BE428086A - - Google Patents

Description

       

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  Improvements to telephone systems;
The invention relates to telephone systems in general, but more particularly relates to automatic switching devices for the treatment of long distance traffic in such systems. The main goal is to provide new and improved switching apparatus and trunk table operating methods, allowing trunk operators to establish and monitor communications more effectively.



   One of the characteristics of the invention is that an operator of a recording position can change her position by operating a key from the recording position to the waiting position or from one point to another and that An operator from a standby position can convert her registration position by resetting a key.

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   Another feature of the invention relates to the method of operation regarding long distance calls from subscribers of a local manual office belonging to the area of a central office.



   Another feature is the inrush current transmission control device.



   Another feature is the arrangement for a trunk operator to control the application of a trouble tone to defective trunk lines in order to mark such lines as "disturbed".



   Another feature is the device for putting on standby the transmission of additional digits by a recording transmitter when an extended automatic selection time is required for automatic level switches.



   Another feature is the call transfer device by means of which any operator can transfer a received call to any other desired operator position of the trunk table.



   Another characteristic is the device by which an operator (by operating an emergency key) can provide an earth potential for starting the researchers of the junction circuits if there is a fault in the distribution equipment.



   Another feature is to provide serial relays in the searcher control lead to control the supervisory lamp to the trunk attendant position.



   Another feature is to provide a disconnection key which must be activated after the long distance operator has operated her keypad to call according to the requested number or the number of the long distance line, in order to automatically disconnect the recording transmitter. when all

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 figures recorded by him were retransmitted.



   Another feature is to provide a recording transmitter having fewer recorders than there are digits in the particular number called.



   The invention will be better understood from the following description relating to the accompanying drawings, comprising Figures 1 to 25 which show by means of usual circuit diagrams, a sufficient quantity of apparatus included in a switching system. long distance to make it possible to understand the invention.



   Fig.l shows a junction diagram showing the local and long distance junction devices of a central office area, Figs. 2 to 25, inclusive, are circuit diagrams
Fig. 26 drawn on the same sheet as Fig. 12 is a layout diagram showing how the various sheets of the plans, Figs. 2 to 25, are to be arranged.



   The arteries of interurban lines,
Referring to Fig. 1, TL-1 and TL-2 trunk lines represent one of the various group of trunk lines running from remote offices to central office or to long distance communications office.



   Long distance traffic over the TL-2 long distance line which passes in tandem through the central office, or originates from this office, can be established to a desired line terminating at the remote office by automatic switches placed there under the central office. Pulse action at voice frequency and likewise for traffic in the opposite direction by line TL-2.



  In addition, long distance traffic originating from the remote end of TL-2 which is to be routed to TL-1 is routed in the same way by automatic switches in the central office.



   The central office of the network uses two numberings

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 6 digits, the first two digits of which designate the desired office on the network, while the remaining 4 digits designate the desired line in the particular office chosen.



   It will be seen from the layout of the junctions of office no.8 of the central office region shown in fig. 1 that the layout of the junctions used is of the standard and well-known type, arranged according to the numbering system generally used in offices using the step-by-step switches, As for the other plans, fig. 2 represents the circuit of a TLC trunk line interposed between the TL-1 two-way trunk line of fig.l and the pads 297 of the bench of the researcher and their multiplication to the researcher Fl shown in fig.6.



   This junction circuit serves as the end of the T-4 circuit from the pads 275 of the bank of the TLS-1 selector, fig. 1 and 9, and their multiplication on the banks of the other selectors, The common starter conductor 286 which ends at the distributor shown in fig.2 is also multiplied on the finder level marking bench in fig.6, in order to mark the particular level on which the finder can find the circuit of the calling trunk line.

   All incoming calls by TL-1 are answered by an indoor operator. watch
Fig. 3 the combined record line CLR junction circuit interposed between the two conductors of circuit T-1 entering through the tenth level of selector OS-1 of the office and the junction circuit TC of the local automatic office n 8 and the studs 360 of the bench of the researcher F-1 of fig. 6 (F-2 of fig.l) and their multiplication in the benches of other similar researchers. Incoming calls received by this long distance line are handled by the CLR operator of the position.

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 universal table.

   Since the researchers F-1 and F-2 with the interior operator equipment and the universal operator equipment are analogous except for slight modifications which will be highlighted below, the researcher
F-1 fig.6 and the equipment of an operator position PE-1 have only been shown in order to simplify the circuit diagram as much as possible. The common starting conductor 313 is connected to the starting relay of the distributor circuit shown in fig. 12 and is multiple to the finder-finder level marking bench in fig, 6 and linked to the particular level on which the finder can find the long distance calling T-1.



   Fig. 4 represents an interurban MR recording circuit interposed between the two conductors of the interurban
T-2 entering through the local manual office n 4 of the central office area and the studs 460 of the researcher's bench Fl of fig. 6 (F-2, of fig.l) and their multiplication on the benches of others analogous researchers.



   The starter conductor 445 is connected to the starter relay known as the distributor of fig. 12 and is multiple on the researcher level marking bench Fl to mark the level of the researcher bench on which the manual recording interurban circuit can be find.



   Fig. 5 represents an ITC transfer circuit from one position to another interposed between the banks of the transfer selector TS of fig. 1 and 9 and the benches of the researcher F-1 of fig. 6 (F-2 of fig.l) and its multiplication on the benches of other researchers. The inter-position transfer circuit is provided to allow an interurban operator of one position to transfer a call to an operator of another interurban position. The common starter conductor 524 is directly connected to the bench for marking the levels of the seeker F-1 in fig. 6 (F-2 in fig.l) to mark the

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 first level of the bench in order to allow the researcher to find the transfer circuit between the calling position.

   The emergency start driver 515 is provided so that the searcher starts immediately without worrying about the conditions of the distributor circuit in fig.12.



   Fig. 6 shows a finder F-1 associated with the position equipment of figs. 11, 13 and 14 and of the type with movement of ascension and rotation, The brushes 618 of the searcher are represented on the left of fig. 6. The finder circuit is provided with a conversation key K1 and a monitoring key K2 and is connected directly through the contacts of the monitoring key to a first interurban selector TFS-1 of fig. 7 which is associated with it. The first TFS-1 long distance selector is individually associated with the finder. The reader conductors of the circuit associating the searcher F-1 with the first interurban selector in fig.7 are multiplied in the banks of junction searchers such as LF-1 and LF-2 in figs.15 and 16 respectively.

   Seeker circuits such as F-1 are accessible by TLC trunk line circuits of Fig. 2, by combined CLR line and recording circuits of Fig. 5, by manual recording trunk circuits MR of fig; 4 and via the first level of each bank provide access to the transfer circuits between ITC-2 positions of fig.5.



   Fig. 7 shows a first TFS-1 interurban selector which is directly associated with the finder F-1 of fig. 6
Fig. 8 shows a TLS-2 trunk selector which is accessible through the fourth level of the first trunk selectors TFS-1 through TFS-4, inclusive, and which provides access to voice frequency trunk lines TS-2 through the 'intermediary to the repeater IR-2 and by levels 6, 7 and 8 of its bench as shown in fig.l.

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   Fig. 9 shows a TFS-1 trunk line selector which is accessible by early trunk selectors such as TFS-1 through TFS-4, inclusive, and which provides access to a trunk line such as TL-1, through the intermediary of the various levels of its bench as shown in fig.l.



  The transfer selectors TS, shown in fig.l, which are accessible via the ninth level of the first interurban selector, provide access through the pads of their bank to transfer circuits between position ITC-1 and ITC-2 of fig. 5.



   Fig. 10 shows the selector of the TOS-11 long distance office which is accessible by the second level of the first long distance switches TFS-1 to TFS-4 and which gives access through the eighth level of its bench and the trunk circuit TC-2 at trunk lines between offices terminating at inbound long distance selector units of mile. In addition, the TOS long distance office selector gives access through the fourth level of its bench and the TC-1 junction circuit to the interurban lines going to the communications request positions of the local manual office No. 4. The TC- junction circuits 1 and TC-2 referring to fig.l are shown in detail in figs.22 and 23 respectively.



   The assembled figs. 11 and 13 represent the equipment of the operator's position and the relays which are common to all the searcher circuits of the same positions which are manually connected to them one at a time by the operation of the conversation keys. circuits of researchers.



   Fig. 12 represents the starting conductors 1200 (which are connected to the individual starting conductors of the line circuits as shown in figs. 2, 3 and 4, according to the levels of the researcher benches through which we end. to these circuits) for controlling common start relay 1210 and for guiding searchers to the particular level they seek for calling lines. Fig. 12

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 also represents the common distributor to the various positions of the table making it possible to distribute the incoming calls to the various operators.



   Fig. 14 shows the keys of the operator positions from K5 to K16, inclusive, which are provided to allow various control maneuvers.



   Fig. 15 shows the circuit of the transmitter SL-1 assembled with the circuit of the finder F-1 and the selector SS-1 of the transmitter.



   The SS-1 transmitter selector associates a free transmitter logger with the SL-1 transmitter circuit, and the LF-1 finder circuit combines the SL-1 transmitter circuit with a finder and the first interurban selector associated with it, such as F-1 in fig. 6 and TFS in fig. 7 respectively. When these connections are made end to end, the operator can control the circuit of the LF-1 seeker to associate the circuit of the transmitter SL-1 with it by means of the equipment of her position in order to route a communication by the "response" side of the researchers.



   Fig. 16 shows the circuit of the SL-2 transmitter assembled with the associated equipment comprising the series of control relays and the operator's DK call keypad. Each operator position has two similar transmitter circuits common to the position.



   Fig. 17 shows the control circuit of the transmitter with registers.



   Figs.18 and 19 represent the control relays of the recorders grouped with; R1 to R6 recorders.



   Fig. 20 shows the switch circuit and the transmitter control relays.



   Fig. 21 shows the pulse counter for controlling the retransmission of the characteristic pulses of the

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 figures received by the various recorders.



   Figs. 22 and 23 show identical interchange circuits TC-2 and TC-1 which are accessible by different levels of the trunk line selectors, Circuit TC-2 is connected to the long distance line T-5 terminating at the automatic office n 8 and the trunk circuit TC-1 is connected to the long distance line T-3 leading to manual office n 4 as shown in fig.l.



   Fig. 24 shows a part of the repeater "R1 of local manual office no. 4 which is associated with the communications call indicator equipment CI-1 as shown in fig.l.



   Fig. 25 shows the remaining part of the repeater Rl of fig. 24 assembled with the supervision lamps and the operator position plug B.



   Fig. 26 is a layout diagram showing how the various sheets of the plans must be arranged to be fully understood.



   A detailed description of the operation of the system will now be given.



     Call from local automatic office 8 to long distance.



   Suppose that the subscriber of set A fig.l of automatic office n 8 wishes to converse with the subscriber reached through TL-2 of fig.l Call from the trunk table of the central office,
When the subscriber picks up his receiver, he is connected to a selector in the office such as OS-1 fig.l via the finder F3.

   It then forms the number 0 reserved for the trunk table and the selector of the OS-1 office chooses a free circuit leading to the trunk table via a trunk circuit such as TC which therefore passes to conditions which characterize it as a calling party to route the call through circuit T-1 to the trunk table

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 via the CLR circuit, fig. 1 and 3.



   The characteristic conditions of call request are therefore imposed on circuit T-1 by the junction circuit TC, fig. l (i.e. an earth or positive potential on the negative conductor and a negative potential on the positive conductor of circuit T-1). The relay 340 of the CLR circuit attracts by its two windings in series with the upper winding of the relay 330 but due to the high resistance of the upper winding of the relay 340, the relay 330 does not attract. Through the armature paddle 341 a negative potential is placed on the type C terminal 360 and on its multiplication through the contacts 331 and the lower winding of the relay 320 to keep the line circuit CLR.



   Through the armature paddle 342 a circuit is closed to bias the winding of the relay 330. A branch circuit leads through the armature paddles 332 to the winding of the relay 310. The relay 330 does not attract since 'it is polarized, but the relay 310 attracts and by the armature pallet 312 places an earth potential on the conductor 313 to mark the level on the benches of the researcher Fl, fig. 6, to which the CLR circuit is connected and for activate relay 1210 in fig. 12.



   By grounding the conductor 313 the relay 1210 attracts. By means of the armature pallet 1211 the ignition circuit of the response pilot light of the various operator positions is closed.



   The researcher starting system.



   Fig. 12 shows the distributor and the common starting wires of which there are ten, generally indicated by the reference number 1200 and being numbered from 1 to 10.



   These last numbers indicate the levels of the researchers (fig. 6) with which the starter conductor 2000 is respectively associated, It will be noted that the conductors of

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 2 to 9, of group 1300 'lead to the contacts of the bank of the vertical broom 617, of the researcher F-1. The tenth contact of the vertical bank of the broom 617 is permanently grounded in order to stop the seeker when the tenth and last level is reached;
Referring to fig. 1, it will be noticed that the first level of the searchers leads either to the 'transfer' circuits between positions such as ITC-1, or to the -first trunk selectors such as TFS-3, through which , deferred calls' are voluntarily routed by the operator.



  This is the reason why there is no conductor in the 1200 group of starting conductors associated with the first level of the researcher bench.



   All the line circuits giving access to a given level of researchers are earthed by the corresponding starting conductors 1200, fig. 12, through the various starting conductors shown in figs. 2, 3 and 4.



   The relays 1210, fig. 12, by drawing under the action of the earth potential on one of the conductors 1200 establishes by the armature-paddle 1211 a circuit to make the response pilot light of each position and by the paddle light up. Armature 1212 closes a circuit to a position starting conductor of one of the four positions which has been preselected by the distributor, or to the next to be selected if none has been preselected.



   With regard to the pre-selection of a position by the distributor in fig. 12, when the attendant is not busy she has received instructions to activate the conversation key of a circuit with seeker and free selector , in order to be ready to receive a call. By means of signal lamps associated with her researchers, an operator can know which researchers are on duty and which are

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 free. The call, answer and busy lamps 601, to 602 and 603 respectively, fig. 6, indicate / the operator of position 1, the situation of the link circuit of the searcher made up of the searcher F-1 , fig, 6, and the first interurban selector TFS-1 fig. 7.



   Preselection of a researcher-selector link circuit.



   If the searcher F-1 is free and the attendant is free for example, she actuates the associated conversation key K1 and thereby establishes a circuit through contacts 696, conductor 604 for the lower winding of relay 670.



  Conductor 604 is one of the common conductors enclosed in cable 1 (which is one of two multiple cables that connect the equipment in position 1 with the group of seeker-selector link circuits assigned to such position). Conductor 604 is normally grounded through armature paddle 1133 of relay 1130.



   By its attraction, the relay '670 of the finder F-1 is blocked by the conductor 605 and by its various armature paddles establishes the link between the finder-selector link circuit and the position equipment.



   In the equipment of the operator position fig.ll the relay 1130 then draws through the conductor 605 of the blocking circuit of the relay 670 and disconnects the earth potential of the conductor 604. By the armature blades 1131 and 1132 the relay 1130 disconnects the associated conversation conductors from the windings of the RC translator coil and extends them to the operator's headband telephone equipment and also establishes a circuit to the earth, / armature pallet 1135, the conductor 1185, the armature pallets 1351,1343, the conductor 1184, the relay 1170, the contact of the key K3 towards the battery.



   Relay 1170 attracts and removes earth potential

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 from the conductor '1188 by the reinforcing pallet 1173; it places an earth potential on the conductor 1189 by the armature pallet 1173 and its front contact; and it connects the driver
1187 to the conductor 1186 by the reinforcing pallet 1172, the latter conductor being connected by the reinforcing pallet 1340, the conductor 1302 and the cable 1 to the connection circuit 'preselected figs.6 and 7.



   If the distributor, fig. 12, is in the normal position shown, the application of the earth potential to the conductor 1189 causes the consecutive operation of the relays 1240, 1250,
1260 and 1270, operation during which the relays perform the test of the position for which a link circuit has been preselected.

   The position which carried out the preselection or (position 1) is characterized by the absence of the earth potential on the conductor 1188. when the relay 1240 attracts it places an earth coming from the armature pallet 1212 through from the reinforcing pallet 1244, on the conductor 1187; it establishes a circuit for the relay 1230 in series with its upper winding by the armature pallet 1242 and by the armature pallet 1241 it opens the blocking circuit by the upper coil of the relay 1270. The relay 1230 attracts in series with the upper coil of relay 1240 and through the armature pallet 1231 opens the initial operating circuit of the lower coil of relay '1240.



   Suppose that the finder scope F-1, fig. 6, is in the position of transfer to the marked vertical bench and that a relay in the equipment of the operator position, fig. 13, is drawn to cause the release of the relay 1170, fig.ll. When releasing relay 1170 the earth is removed from the conductor
1189 and relays 1230 and 1240 release and the distributor relays return to their normal position. However

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 if the operator in position 4, for example, has her conversion key in its working position, the earth coming from the starting relay of the distributor associated with this position maintains the blocking circuit of relay 1230 and the winding top of relay 1240 prevents its release at this time.

   Therefore when earth is placed on conductor 1188, a circuit is established through armature paddle 1234 for the lower winding of relay 1250. Relay 1250 pulls in and locks by paddle. armature 1252 in series with relay 1230 and at the same time opens the blocking circuit of the upper winding of relay 1240 by the armature pallet 1251.



   Since the operator in position 2 does not have a conversation key in the working position, an earth is applied to the guard conductor connected to position 2, consequently causing the attraction of relay 1260 via the paddle d armature 1253. The relay 1260 attracts and blocks by its upper winding in series with the relay 1230. Since the ground of the starting conductor of position 3 is now connected through the armature paddle 1263 to the lower winding of relay 1270, relay 1270 attracts and blocks by its upper winding the armature pallets 1272 and 1241 in series with relay 1230.

   Under the action of the attraction of relay 1270, the earth potential is placed on the position starting conductor which leads to the equipment of the operator in position 4. Uand the researcher link circuit associated with the position 4 is in the transfer position on the level of the marked vertical bench, the earth potential will be placed via the armature pallet 1273 of the guard conductor on the winding of the relay 1220. Under the action of the operation of the relay 1220 the holding circuit of relays 1230 and 1270 is opened by the armature pallet 1221

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 causing the release of this relay.

   By means of the armature paddle 1273, the relay 1270 opens the initial excitation circuit of the relay, 1220. The 1220-being release delay relay does not drop out and does not close the armature pallet 1221 until the 1230 release delay relay has had sufficient time to drop out. The sequence of operations is then repeated to test the various positions until the position is found at which the attendant has activated her conversation key and is ready to answer incoming calls.



   Searching for the calling line,
Now returning to the preselector-researcher F-1, fig. 6, earth goes through reinforcing pallet 1244, conductor 1187, reinforcing pallet 1172, conductor 1186, reinforcing pallet 1344, starter conductor 1302, in cable 1, pallet 'armature 677 from relay 670 (finder Fl, freeze 6) to the winding of relay 660 and the battery.



   Relay 660 draws and sets up a circuit to drive relay 650 through armature paddle 662 and establishes a circuit for the bias windings of relays 610 and 620 through armature paddle 663. A branch of the established circuit by the reinforcement pallet 663 passes through the reinforcement pallets 615, 641 and 635, the winding of the vertical GREEN electromagnet towards the battery. The GREEN vertical electromagnet attracts and advances the finder-finder in vertical steps. By attracting the vertical electromagnet GREEN closes a circuit through the armature paddle 698 of the relay 640 which attracts and opens the initial circuit for energizing the vertical electromagnet through the armature paddle 641.

   The vertical electromagnet releases and opens the circuit of relay 640 which also releases to close the circuit of the vertical electromagnet.

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   This interaction is repeated until the vertical broom 617 comes into engagement with the contact of the previously grounded vertical bench from which it follows that the relay 640 is blocked through a circuit including the starting conductor. ground to the level on which the vertical broom 617 is located, the lower coil of the relay 640, the armature paddle 633, the coil of the relay 640 and the battery. Relay 630 draws in series with relay 640.



  Relay 630 is a bit slow to release and is combined such that its armature paddle 632 first attracts and establishes a blocking circuit through its top winding as follows: earth, top winding of relay 630, con- head tacts 645, ineffective contacts 646, armature paddle 632, resistor R4, battery. Through armature paddle 635 relay 630 transfers the operating circuit from the GREEN ascension electromagnet to the rotation electromagnet ROT and through armature paddle 632 establishes a circuit for relay 1340 ( fig. 13) by: battery, resistor R4, armature paddles 632, 676, conductor 608, cable 1, winding of relay 1340 and earth.



   In addition, the relay 630 through the armature paddle 633 opens the circuit of the relay 640 which de-energizes and closes its armature paddle 641 and its rest contact to establish an operating circuit of the rotation electromagnet ROT. The rotational solenoid ROT and relay 640 react to each other as described above with respect to the vertical solenoid until the brushes 618 engage with each other. the pads 360 of the bench corresponding to the calling line (fig. 3). Consequently, when the stud c is in contact with one of the finder's brushes C-1 or C-2, the finder's movement stops.



   Suppose that the researcher's brush C-1 is the stud C,

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 EMI17.1
 the following circuit is then established: bei; ' f. lower winding of relay 320 of the CLR circuit, fig. 3, armature pallet 331 and 341, conductor C and bench pad or pad 360 is on which / the brush C-1, active winding of relay 610, armature pallet 623, lower winding of relay 650, reinforcement pallet 634, earth.



   By pulling the relay 610 establishes a guard circuit through its middle winding and through the armature vane 614 from the earth to the armature vane 634 while through the armature vane 615 it immediately opens the circuit of the ROT rotation electromagnet to stop the rotation movement. Speaking of armature paddles 611 and 612, relay 610 connects brushes 1 negative (-1) and positive (+1); through armature pallet 613 it bypasses the active winding of relay 610, thereby connecting the earth given by armature pallet 634 through the lower winding of relay 650 and through armature pallet 613 apply an earth directly to the associated brush C-1 to keep the CLR circuit, fig. 3, and to provide a direct circuit to relay 320 of the CLR circuit in series with relay 650 of finder F-1.



   In the CLR circuit, fig, 3, the relay 320 attracts and opens the circuit of the relay 310 through the armature pallet 322 and through the armature pallet 321 it prepares a circuit to bypass the high resistance of the upper winding of the relay 330. Relay 310 therefore releases and through armature paddle 311 establishes the shunt circuit of the top coil of relay 340 and through armature paddle 312 removes the starting earth potential of conductor 313 ,. The high resistance top winding shunt circuit of relay 340 shown above causes sufficient current to flow through the leads of the T-1 junction circuit to force the TC junction circuit to be blocked, Fig.

   1,

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 and to allow the call to be kept by the trunk table in the central office. The relay 330 does not attract because the potential applied to the conductors of the circuit T-1 is applied in the reverse direction to the junction circuit TC, fig, 1 as soon as it is seized from which it follows that a positive potential is now applied to the upper or negative conductor of circuit T-1 and a negative potential is applied to the lower positive conductor.



   In the office ? 8, freeze 1, from where the call is emitted, the reinforced current flows in the conductors of the circuit T-1 and in addition to the guard of the communication under the control of the operator of the central office causes the application an identification tone normally given on entry of the circuit to cease after a sufficiently long time interval to allow the long distance operator at the central office to take note of the type to which the calling line must be attached. The relay 350 is designed to reopen the supervision bridge by operating the call and answer key on the part of the operator in order to cause, if necessary, a new momentary application of the identification tone.

   This new application is performed by removing the short circuit of the supervisory bridge by attracting the relay 310 by the armature paddle 351 of the relay 350. The relay 310 attracts through this circuit and opens the shunt circuit of the upper winding resistance of relay 340 by armature pallet 311. This has the effect of introducing the high resistance top winding of relay 340 into the circuit comprising the conductors of circuit T-1 which produces the necessary operations in the circuit. of the TC junction in fig. 1 to reapply the identification tone to the connecting conductors of circuit T-1.



   In researcher F-1, fig. 6, when the relay 610 draws a circuit is established from the ground to the paddle

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 armature 663, the armature pallet 616, the normal
EC incorrectly closed of the NP shaft springs, EC1 brush, stud / 560 of the CLR circuit control electromagnet, fig. 3, 360 lamp, to the battery. This lamp indicates to the long distance operator the line or trunk group through which the call is received.



   Note that a resistor R4 is included in the blocking circuit of relay 360, fig. 6. It is intended primarily to allow relay 630 to be bypassed and therefore to release under the control of the position equipment, fig, 13.



   Applying the battery to conductor 608 (fig. 13) causes a circuit to be established for relay 1340 which pulls, to open the previously described circuit of relay 1170, fig.11.



  Relay 1170 is slow-operating and remains attracted for a short time after the circuit is opened.



  A circuit is then established by a ground to the armature pallet 1341, conductor 1183, armature pallet 1171, normally closed contacts of the armature pallet 1162, relay winding 1140 and the battery.



   When relay 1140 attracts it disconnects the operator's headband equipment from conductor 1180 and places an earth potential on conductor 1181 and extends conductor 1180 from the operator's headband to conductor 1191 by the 'through the armature paddle 1141 and the normally closed contacts controlled by the armature paddle 1142. A distinguishable high frequency tone is therefore transmitted through the forward contact of the paddle. armature 1141, from the front contact of the armature pallet 1131, from the right winding of the induction coil I, the resistance AL of the artificial line, from the front contact of the armature pallet 1132, to Earth

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 to the reinforcement pallet 1142.



   Relay 1140 establishes a circuit for relay 1150 through armature paddle 1143. Relay 1150 draws in, interrupts the ringing tone current through armature paddle 1151 and at the same time establishes a circuit for relay. 1160 by an earth given by the armature paddle 1152. The relay 1160 then draws and applies again the call tone current through the armature paddle 1161 at the same time as it blocks itself by the conductor 1183 earthed by the armature pallet 1162 and thus opens the initial energizing circuit of relay 1140 by the normally closed contacts, controlled by the armature pallet 1162, Relay 1140 releases after a short time interval and ends the two short applications of the high-frequency calling tone to the connected operator.

   Releasing relay 1140 again connects the operator's headband to conductors 1180 and 1181 through the armature paddles 1141 and 1142 and opens the energizing circuit of relay 1150, which consequently releases and opens the circuit. initial energization of relay 1160 by armature pallet 1152. However, relay 1160 remains in its attracting position thanks to a protective earth on conductor 1183 until relay 1170 releases and opens the blocking circuit from relay 1160 by the reinforcement pallet 1171.



   De-energizing relay 1170 removes the earth potential of conductor 1189 and places an earth potential on conductor 1188. Removing the earth of conductor 1189 allows relays 1230 and 1240 of distributor fig, 12 to be released. another operator has maintained an earth potential on the starting conductor of the distributor, these relays remain attracted and the distributor proceeds to the preselection of another position.

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   At the end of the call signal current in the receiver of the operator, the latter can immediately converse with the subscriber calling through the conductors 1180 and 1181, the reinforcing pallets 1311 and 1312, the conductors 653 and 654, cable 1, the armature paddles 674 and 672, the armature paddles 612 and 611, the positive +1 and negative-1 brushes and the repeater 300 of the CLR circuit, fig. 3, connected to circuit T-1 entered by the calling subscriber.



   After ascertaining the number (office and subscriber number) of the called subscriber who is supposed to be at the long distance office at the far end of TL-1, the long distance operator proceeds to send this number to a recorder chosen by operating its DK send key, fig. 16.



   Selection of a freed recorder.



   The operator in position 1 has two recorder circuits for her exclusive use SL-1 and SL-2, figs, 15 and 16, respectively. These recorder circuits provide access via the LF-1 and LF-2 searcher circuit to several searcher-selector circuits in position N 1. These recorder circuits also provide access via selectors SS-1 and SS-2 recorders to a group of recorders intended for common use by all operators.



   The relays 1610, 1620 and 1630 automatically attract to operate the SL-1 recording circuits alternately, fig. 15 and SL-2, fig, 16.



   Relay 1340, fig. 13, attracted 'as a result of the operation of relay 630 and by attracting extends the earth applied to the conductor 1185 through the intermediary of the armature pallet 1135 the relays 1610, 1620 and 1630, the armature pallets 1351, 1343, 1362, .1393, conductor 1304, reinforcement pallet 1623 of relay 1620, fig. 16, relay winding

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 1610 to the battery assuming relays 1610, 1620 and 1630 are all at rest.

   Relay 1610 attracts and blocks in series with the left winding of relay 1620 by the following circuit: battery, winding of relay 1610, armature paddle 1613, left winding of relay 1620, normally closed contacts controlled by the paddle armature 1633, springs 1 and 2 of key K4, conductor 1190 to the earth given by armature pallet 1111, relay 1110 being energized as long as the operator has her microphone-receiver equipment plugged into the jack.

   Relay 1620 does not attract through this blocking circuit at this time since its left winding is shunted by the initial operating earth potential applied to relay 1610 through conductor 1304. When relay 1610 attracts it closes a circuit from brush 1506 of the SL-1 recorder circuit, fig. 15, the normally closed contacts controlled by the armature pallet 1583, the armature pallet 1596, the conductor 1647, the armature pallets 1616 and 1625, the conductor 1648, the self-interrupting contacts of the electromagnet SSM, the winding of the SSM electromagnet towards the battery.

   If the recorder to which the SS-1 Recorder Selector brushes are stopped, is busy, the test lead will be grounded and the above circuit is established to operate the rotating solenoid. . The SSM solenoid attracts like a buzzer to advance the brushes of the SS-1 recorder selector until they find a free recorder. A test circuit is also established by: earth, to the normally closed contacts controlled by the armature paddle 1585 of the relay 1580, fig, 15, conductor 1644, armature paddle 1612, armature paddle 1622, conductor 1643 , winding of relay 1590, self-interrupting contacts of the solenoid

  <Desc / Clms Page number 23>

   SSM, winding of the SSM solenoid towards the battery.



  Relay 1590 is grounded, which operates the SSM solenoid as long as SS-1 Logger Selector Test Brush 1506 encounters a ground potential.



   When the free recorder is found the relay 1590 is not bypassed any longer and therefore attracts in series with the SSM solenoid. Due to the high resistance of relay 1590 the SSM solenoid will not attract and the SS-1 log selector brushes will remain in place.



   When relay 1590 pulls it disconnects test brush 1506 from the test circuit and connects it to ground through armature paddle 1596 to mark the recorder as busy. In addition, relay 1590 connects the operator's DK send key, fig. 16, to the recorder and prepare circuits in the SL-1 recorder circuit.



   As a further result of the operation of relay 1610 an outgoing circuit is established for the LFM solenoid of the LF-1 finder circuit by armature paddle 1611 and a test circuit is established by armature paddle 1614 for relay 1610. Researchers normally place a ground potential on the test leads and when a finder is preselected the ground is removed from the test lead. Therefore when the circuit is closed from the test brush 1527 of the LF-1 finder circuit through the winding of the LF-1 electromagnet, the earth encountered by the test brush 1527 causes the electro to attract. - LFM magnet in the manner of a buzzer so that it moves the brushes 1522-1527 of the LF-1 seeker circuit forward.

   Relay 1510 is shunted during this operation of automatic selection of the LFM electromagnet by the earth encountered by brush 1527. When the brushes arrive on the group

  <Desc / Clms Page number 24>

 of the pads associated with the circuit composed of F-1 and TFS-1, the test brush 1527 will not encounter earth on the conductor 1557 and the relay 1510 is not shunted any longer and attracts by: earth, paddles armature 1624 and 1614, conductor 1645, winding of relay 1510, self-interrupting contacts of the LFM solenoid, winding of the LFM solenoid, towards the battery. Relay 1510 attracts in series with the LFM solenoid but the LFM solenoid does not attract due to the high resistance of relay 1510.



   When pulling relay 1510 a circuit is established through the earth given by armature paddle 1515, test brush 1527, conductor 1557, cable 2, armature paddle 675, conductor C773 going to TFS-1, fig. 7. In addition by the reinforcing pallet 1512 a ground is given by the brush 1524, the conductor 1554, cable 2, the conductor 1554 which is also connected to the conductor C773 going to TFS-1, fig. 7. When earth potential is applied to conductor C773 a circuit is established through head contacts 750 and the coil of relay 730 to the battery.



   In addition, the relay 1510 through the armature pallet 1516 establishes a circuit from the earth to the armature pallet 1516, the armature pallets 1535 and 1598, the recorder 1, the modeling light 1500. This lamp illuminates for indicate to the operator that she can then send the requested number using her DK send keys.



   The relay 1510 by the, armature pallet 1516 also establishes a circuit for the relay 1570 which by drawing establishes the operating circuit * of the relay 1560 and prepares a guard circuit for the relay 1580 by the armature pallet 1572.



   Conductors A, B, C and D coming from the operator's DK sending keys, fig. 16, go through

  <Desc / Clms Page number 25>

 armature paddles 159,1-1594 of relay 1590 and brushes 1401-1504 of the SS-1 recorder selector to the corresponding conductors leading to the recorder, fig. 18 and 19.



   SL-1 recorder circuit relay 1590, fig. 15, attracting connects the ground potential to brush 1506 to actuate relay 1730 through conductor 1507, armature paddle 1711, upper and lower windings of relay 1730, and battery. In addition by the armature pallet 1595 of the relay 1590 a polarization circuit is established from the battery to the relay 1520, the normally closed contacts of the armature pallet 1551, the armature pallet 1595, the broom 1505, the conductor 1508, passing through figs. 17, 18 and 20, the reinforcement pallet 2021, the winding of the relay 2040 towards the earth. 'Relays 1520 and 2040 attract through this circuit, impulse relay 1520 establishes a circuit through armature paddle 1521 for relay 710 of the first trunk selector TFS-1, fig. 7, by:

   battery, upper winding of relay 710, armature pallet 741, negative conductor 771, conductor 1552 of cable 2, negative brush 1522, normally closed contacts controlled by armature pallet 1531, armature pallet 1521 of relay 1520, the armature pallet 1511, the positive brush 1525, the conductor 1553, the cable 2, the positive conductor 772, the armature pallet 742, the lower winding of the relay 710 to the previously grounded conductor C773. Relay 710 attracts and prepares the switch for further operations.



   Operation of relay 2040 in series with relay 1520 disconnects conductor 1754 and conductor 1755.



   Save the requested number,
Suppose that the number of the inter-office junction requested is 13 and that the long distance operator has operated

  <Desc / Clms Page number 26>

 consequently the sending keys of its call keypad DK to route the communication, The operation of a sending key has the effect of placing an earth potential on one or more of these conductors and in order to simplify understanding of the circuit the conductors earthed as a result of the operation of each key have been indicated in brackets above each key.



   The relay 1730., fig. 17, was previously energized and by the armature pallet 1731 applies a ground to the conductor 1750 which is extended through the armature pallet 1821 to the winding of the relay 1890.



  In addition, a ground on conductor 1750 prepares a guard circuit for various relays. The relay 1890 attracts and through the armature pallets 1891-1894 extends the conductors A, B, C and D associated with the group of operator keys up to the corresponding relays Al, Bl, Cl and Dl of the recorder R-1. The attendant can then send the digits 1 and 3 of the number of the desired inter-office junction to the recorders.



   When the attendant operates the key 1, the conductors A and B are earthed and cause the operation of the relays Al and Bl of the recorder R-1, fig, 18. By attracting the relays Al and Bl are blocked by the 1815 and 1816 armature pallets through the top winding of relay 1820, armature pallet 1842 and conductor 1750. Relay 1820 does not attract because it is shorted upon application an earth potential to conductors A and B. As soon as key 1 operated is released, the shunt is removed from the winding of relay 1820 and this relay draws in series with relays Al and Bl of recorder R -1.



   The relay 1820 by attracting is blocked by its lower winding, the armature pallets 1812 and 1821 and the

  <Desc / Clms Page number 27>

 conductor 1750. A branch circuit is also established via the armature pallet 1851 and the relay 1895. The relay 1895 attracts and connects the conductors A, B, C and D of the keys via the pallets d frame 1896-1899 to the R-2 recorder. Through the rear contact of the armature pallet 1821, the relay 1820 opens the excitation circuit of the relay 1890 which releases and disconnects the conductors A, B, C and D of the keys of the recorder R-l. Through the armature paddle 1822 the relay 1820 establishes a circuit from the ground through the armature paddles 1825 and 1826, the armature paddle 1822, the conductor 1751, the winding of the relay 1720 to the battery.

   Therefore relay 1720 attracts when recording the first digit of the number to cause the digit which will immediately be transmitted as pulses to the SL-1 recorder circuit, freeze 15, and: retransmitted from there , perform the necessary operations to activate the first interurban selector TFS-1, fig. 7,
During the attraction of the relays Al and Bl an earth is connected to the armature pallets 1832 and 1833 towards the conductor 1 of the marking conductors 1800 leading to the pulse counting relays, fig, 21. This earth passes through the conductor 1750 the 1983, 1953 and 1923 rebar pallets, the 1836 driver, the 1875, 1843, 1832 and 1833 rebar pallets.



   When the attendant operates the send key 3 of the DK call keypad to record the second digit of the junction number, the A and D conductors are earthed and consequently the A2 and D2 relays of the recorder R2 attract via the armature pallets 1896 and 1899. The A2 and D2 attracting relays lock in series with the top winding of the relay 1850 via the armature pallet 1872 and conductor 1750. Relay

  <Desc / Clms Page number 28>

 1860 remains short-circuited as long as the key remains operated and attracts as soon as the key releases and establishes a blocking circuit by its lower winding by the armature pallet 1851 and by its front contacts starting from the conductor 1750 by the 'Intermediate of the frame pallet 1821.

   In addition, the blocking circuit for the lower winding of relay 1850 is also extended through the armature pallet 1881 to cause the operation of relay 1875.



  Through the rear contact of the armature pallet 1851, relay 1850 opens the circuit of relay 1895 which releases and opens the initial energizing circuit of the recording relays of the R-2 recorder. By the armature pallet 1852 an earth is given by the armature pallets of relays A2 and D2 (not shown) to maintain a blocking earth on conductor 1751. Conductor 3 of the marking conductors
1800 is not marked by an earth potential which would be applied to it since this relay 1840 did not attract or establish the marking circuit via the front contact of the armature pallet 1843. The relay 1840 does not not attract until the pulses corresponding to the recording made on the R-1 recorder have been transmitted, by the operation of the pulse counting relays, fig. 21.



   In the case of the communication described, the attendant only records two digits, However if it is necessary for the attendant to record more than six digits, he will continue to operate the DK sending keys according to this number, attracting and lock in their working position, the recording relays of recorders R-3 to R-6, freeze 18 and 19, in series with the associated transfer relays such as 1930 and 1990.



   Suppose the long distance operator has manipulated her DK send keys to register six digits. When the last recorder is activated and the 1990 relay has

  <Desc / Clms Page number 29>

 blocked a ground is also placed through the conductor 1838 on the winding of the relay 1810 towards the battery. The 1810 relay draws and through the armature pallet. 1812 it opens the blocking circuit of the lower winding of relay 1820. Since the first recorded digit has been betrayed by the pulse transmitter, relay 1820 is prepared to release because the circuit including its upper winding is open. as a result of the relays of the R-1 recorder being released which were drawn under the control of the 1840 relay.



   When relay 1820 releases the blocking circuit for the lower windings of all transfer relays is opened by the armature vane 1821 and its front contact and by the rear contact of the armature vane 1821 a circuit is established starting of conductor 1750 to attract relay 1890 again. In addition, releasing relay 1820 also opens the relay excitation circuit
1810. The relay 1810 releases and again prepares the blocking circuit of the relay 1820 by the armature pallet 1912. This blocking circuit however is not established until the relay 1820 is attracted again. Relay 1890 attracts and connects logger relays R-1 to control conductors A, B, 0, and D in the same manner as previously explained.



   When the lower winding blocking circuit of the transfer relays is open, the transfer relays of the recorders which have been released will immediately return to idle and the transfer relays of the recorders which are still drawn will remain energized. As soon as the pulse transmitter transmits pulses corresponding to the recording on one of the recorders put into service, the relay associated with the output command opens the circuit.

  <Desc / Clms Page number 30>

 comprising the upper winding of the transfer relay and the recording relay (s) used. Since the lower winding block circuit has been opened the transfer relay will then release. The other recorders and transfer relays will each return to their normal position.



   At the same time as the pulse transmitter transmits pulses corresponding to the recording on the recorders, which have not returned to idle, the operator can maneuver her send keys to record digits a second time on the recorders returned to idle. Relay 1820 will draw in series with the same recording relay (s) drawn in the manner described above.



  The other recorders can be put back into service successively and when the last recorder is put back into service the same cycle of operations can be repeated.



   The pulse transmitter, fig. 21, will lag slightly on the recording relays, therefore a DC ground potential is placed on conductor 1751 by the attracted recording relays. When the pulse transmitter picks up the loggers in service, the earth potential will be removed from conductor 1751 and will therefore cause relay 1720 to release, fig. 17, in order to defer a new transmission of the pulses by the pulse transmitter until the next recorder has been put into operation.



   If the attendant discovers an error while operating the sending keys, she can stop the part of the number that was recorded by operating the ER key. This pulls relay 1360 of the equipment into the operator position, fig. 13, via the conductor 1450. The relay 1360 opens the initial circuit of the relay 1610. From which it follows

  <Desc / Clms Page number 31>

 that the relays 1610 and 1620 pull in series through the conductor 1190. The pull relay 1620 releases the SL-1 logger circuit and prepares a circuit through the armature paddle 1623 to pull the relay 1630. The Releasing the SL-1 recorder circuit allows the release of the selected recorder equipment and each switch controlled by the recorder.

   When the relay 1360 releases when releasing the key ER the recorder circuit SL-2, fig, 16, is seized, When the relay 1360 attracts again and closes the circuit through the armature paddle 1362 the potential earth applied to conductor 1304 establishes relay 1630 circuit causing recorder circuit SL-2 to start LF-2 finder circuit and recorder selector SS-2 to operate. the same manner as that described with regard to the operation of the SL-1 recorder circuit, fig, 15.



   Switching on the pulse transmitter.



   Pulse transmitter control circuit relay 1720, Fig, 17, is pulled when earth potential is applied to conductor 1751. Upon pulling relay 1720 a circuit is established by armature paddle 1721 for the relay 1740. By attracting the relay 1740 is blocked by the armature pallet 1741 and at the same time opens its initial excitation circuit. Through the armature paddle 1723 the relay 1720 opens the circuit of the conductor 1755 at one point and through the armature paddle 1743 places a ground potential on the conductor 1752 to establish a circuit for the relay 2010, fig. 20, and cause the retransmission of the pulses of the recorded digits.



   During the attraction of the relay 2010 a blocking circuit is established by the armature pallet 2011 and by the armature pallet 2012 a circuit is established to operate-

  <Desc / Clms Page number 32>

 Relay 2020. Relay 2020 establishes an excitation circuit for relay 2030 through the armature pallet 2021.



  By pulling the relay 2030 opens the initial circuit of excitation of the relay 2010 by the armature pallet 2031. The relay 2010 releases and opens the circuit of the relay 2020, this relay on releasing opening the circuit of the relay 2030. On releasing relay 2030 again restores the original circuit of relay 2010. This cycle of operations continues until the 1752 conductor is no longer grounded.



   While the 2020 relay is drawn into the circuit comprising the 2040 and 1520 relays in series of the recorder circuit, fig. 15, is opened by the armature pallet 2021. Momentary release of relay 1520 opens the circuit loop of relay 710 of the first interurban selector TFS-1, fig. 7.



  When relay 2020 releases, the circuit of relays 1520 and 2040 in series is again established thereby looping the circuit of relay 710 again through the armature paddle 1521. Additionally the first time relay 2020 puts current on the 1754 conductor which extends through the 2022 rebar pallet, 2095 conductor to the 2100 relay winding and the battery. The starting relay 2100 associated with the relays 2101-2110, attracts and blocks by the armature pallet 2131, the armature pallets 2121-2130 of the relays 2101-2110, the conductor 2094, the armature pallet 2054, conductor 2093, lower coil of relay 2101, conductor 2090, rebar pallet 2051, rebar pallet 2062 to conductor 1754.



  No current will flow through the blocking circuit of relay 2100 as long as the initial circuit of that relay remains on. However when relay 2020 releases release 2101 draws in series with relay 2100 to connect conductor 1 of the marking conductors 1800. Relay 2101

  <Desc / Clms Page number 33>

 establishes a blocking circuit for itself by the armature pallet 2111 from the conductor 2090. In addition, the relay 2101 opens its initial excitation circuit from which follows the release of the relay 2100 and by the front contact of armature pallet 2121 prepares the circuit of relay 2102.



   Since conductor 1 of the marking conductors 1800 is marked by the R-1 recorder, relay 2050 draws through a circuit comprising its bottom winding, conductor 2096 and armature pallet 2141. A circuit is then established by the armature pallet 2055 to prevent conductor 1508 from being opened by the armature pallet 2021 of the relay 2020. This shunt circuit established on the circuit by the armature pallet 2021 prevents the transmission of an additional pulse during operation of relay 2020.



  The pulse forming the digit 1 as recorded by recorder R-1 is therefore terminated.



   In addition to the shunt circuit shown above for conductor 1508, relay 2050 blocks by a circuit comprising its top winding, armature paddles 2053 and 2083, and conductor 1754. Through armature paddle 2154 the relay 2050 prepares a circuit for the 2060 relay; the reinforcement pallet 2051 and its rest contact it removes an earth from the conductor 2090 allowing the relay 2101 to release and through the front contacts of the reinforcement pallet 2051 it extends the conductor 1754 by means of the pallets d 'reinforcement 2062,2051, 2081 towards the conductor 1975. This earth is extended by the reinforcement pallets 1981, 1951 and 1921, the conductor 1833, the reinforcement pallets 1871 and 1831 towards the winding of the relay 1830 and battery.

   Relay 1830 attracts and through the armature pallet 1831 prepares a blocking circuit for itself in series with relay 1840. Also long. that the earth is maintained on the conductor 1975 the circuit of relay 1840 is shunted by the conductor 1750. However

  <Desc / Clms Page number 34>

 when earth is removed from the 1975 conductor the 1840 relay pulls in series with the 1830 relay.



   Since the 1751 conductor is grounded by the recording relays which are pulled in, the 1740 relay maintains a ground on the 1752 conductor and thereby keeps the 2010,2020 and 2030 relays drawn. Therefore during operation. Following relay 2020, relay 2100 draws again through the circuit comprising conductor 1754, armature pallet 2022 and conductor 2095.

   When relay 2020 releases and opens the circuit, relay 2100 establishes a blocking circuit for itself in series with the lower coil of relay 2060 by: battery, coil of relay 3100, armature pallet 2131, pallets of reinforcement 2121-2130, conductor 2094, reinforcement pallet 2054, reinforcement pallet 2064, lower coil of relay 2060 to conductor 1754,
The 2060 relay by attracting gets blocked by the 1754 conductor and a circuit comprising its top winding, the 2063 armature pallet and the 2083 armature pallet, it prepares a circuit for the 2070 relay through the 2065 armature pallet which s 'sets at the end of the interval between sending the first and second digit;

   it extends the conductor 1754 to the conductor 2090 via the armature paddles 2072 and 2061, it opens its excitation circuit to the rear contacts of the armature paddle 2064 thereby releasing the relay 2100; the front contact of the reinforcement paddle 2064 it prepares a new circuit through the armature paddles 2074 and 2054 to start the operation of the pulse counter relays in order to count a determined number of attractions of the relay switch and by the same / duration of spaces between two digits;

   and by the reinforcement pallet 2062 it disconnects the earth potential of the conductor 1975,

  <Desc / Clms Page number 35>

 After this last operation, the winding of relay 1840 is not shunted any longer and it draws in series with relay 1830. This has the effect of transferring the 1975 conductor to the winding of relay 1860 associated with relay 1870. When the 1975 conductor is next grounded the 1860 relay will pull and when the earth potential is removed the 1870 relay will pull in series with the 1860 relay in order to connect the R-3 recorder to the 1800 marker conductors. Further through the armature pallet-1842, the relay 1840 opens the guard circuit of the relay 1820 and the logging relays drawn from the logger R-1.

   The attracted recording relays will release but relay 1820 remains in its attracted position by the action of a blocking circuit comprising its lower winding and conductor 1750.



   If the attendant has not put the recording relays of the second recorder in serive by means of her DK send blocking keys, the earth (s) of the recording relays will be removed from the conductor 1751 by releasing the recording relays of the recorder. R-2 and therefore will de-energize relay 1720. Relay 1720 by releasing an earth on conductor 1755 through armature pallet 1723.



   By the attraction of the relay 1840 an earth is removed from the armature pallet 1843 and at its rear contact is conductors marking 1800 and / transferred via the front contact of the armature pallet on the R-2 logger relays to ground conductor 3 of the 1800 marking conductors.



   With relays 2050 and 2060 blocked in the catch position and with relays 2101-2110 released, the circuit is then prepared for counting the interval time between the transmission of the recorded digits. When the relay

  <Desc / Clms Page number 36>

 
 EMI36.1
 2100 is drawn the next time paf '1è' ê'1'a '! S 2020, it does so when the circuit is established by the armature vane 2022 and is blocked in series with the lower winding of the relay 2101, when relay 2020 releases again, through the following circuit: battery, winding of relay 2100, armature pallet 2131, armature pallets 2121-2130 of relays 2101-2110, conductor 2094, armature pallets 2064 and 2074, conductor 2093, lower winding of relay 2101 to conductor 2090.

   The relay 2101 establishes a blocking circuit for its upper winding through the armature pallet 2111 and the conductor 2090 and through the armature pallet 2121 it opens its initial excitation circuit and the blocking circuit. of relay 2100.



  Therefore when relay 2100 draws the next time it locks in series with the lower winding of relay 2102 when its initial drive circuit is open. Relay 2102 establishes a blocking circuit for its upper winding through armature pallet 2112 and opens the circuit of relay 2100 at the rear contact of armature pallet 2122 and through the front contact prepares the circuit for winding of relay 2103. Note that the counting relays establish the circuit for testing the 1800 marking conductors by the armature paddles 2141, 2142, etc. but because the relay 2050 is drawn to an earth potential encountered on any one conductors marking 1800 has no effect.

   The following counting relays are successively attracted by the successive attractions of relay 2100 until relay 2070 attracts. The moment at which relay 2070 is drawn depends on the position of distribution conductor 2180. As shown, distribution conductor 2180 interconnects terminal 2186 associated with relay 2070 through the connector.

  <Desc / Clms Page number 37>

 conductor 2092 and rebar 2065 with terminal 2183 connected to the top winding of relay 2104.



  Thus when the relay 2104 attracts and is blocked by the conductor 2090, a circuit is closed through the intermediary of the distribution conductor 2180, the conductor 2092, the armature pallet 2065 of the relay 2060 towards the lower winding of the relay 2070. Relay 2070 attracts and prepares a circuit for switching on the transmission of pulses because the figure has been recorded on the recorder R-2, fig. 18,
Pulling relay 2070 establishes a blocking circuit for its upper winding through armature paddle 2073 and removes ground from conductor 2090 through armature paddle 2072 thereby allowing attracted count relays to release again. .

   When this is and at the same time the relays 2050, 2060 and 2070 are pulled, the next time the relay 2100 is pulled in a blocking circuit closes for the relay 2100 in series with the lower winding of the relay 2080. This blocking circuit passes through: winding of relay 2100, armature pallet 2131, 2121-2130, conductor 2094, armature pallets 2054, 2064, 2074 and 2084, lower winding of relay 2080 towards the conductor 1754. Relay 2080 establishes a blocking circuit for its top winding through armature pallet 2082 in multiple with armature pallets 2052, 2062, and 2072 to conductor 1754.

   Through the armature paddle 2084 the relay 2080 opens its initial excitation circuit to allow the relay 2100 to release and through the armature paddle 2081 it opens at one point the circuit of the output control relays by the 1975 driver. Through the armature pallet 2083, relay 2080 opens the blocking circuit of relays 2050,2060 and 2070 to allow all these relays to release. When the relays

  <Desc / Clms Page number 38>

 2050, 2060 and 2070 release they disconnect the 1754 conductor from the upper winding of the 2080 relay to allow this relay to release, The shunt placed on the 2021 pulse contacts of the 2020 relay is removed when the 2050 relay is released .



   With relays 2050, 2060, 2070 and 2080 released again and with relays 2101-2110 also released, the pulse transmitter device can then transmit and count the pulses constituting the second digit recorded on the R-2 recorder. by the long distance operator.



     Very pulses are then transmitted by the armature pallet 2021 of the relay 2020 by which the time relays 2101 and 2102 have been attracted to test the marking conductors 1 and 2 belonging to the marking conductors 1800; and the blocking circuit of relay 2100 comprises the lower winding of relay 2103. Then when relay 2020 releases to complete the third transmitted pulse forming a train and at the same instant it opens the initial circuit of relay 2100, the relay 2103 attracts through the blocking circuit of relay 2100 and connects the third conductor of the marking conductors 1800 to the lower winding of relay 2050 which attracts and gives the same effects as previously described.

   However, at this time the grounding of the 1975 conductor by means of the armature 2051 of the relay 2050 establishes a driving circuit for the relay 1860. The relay 1860 in turn prepares a circuit for the relay 1870.



  When earth is removed from the 1975 conductor by the next pull of relay 2060, relay 1870 pulls in series with relay 1860 through the circuit comprising conductor 1835, armature paddle 1922, and conductor 1750. The attraction of relay 1870 transfers the marking earth potential from recorder R-2 to recorder R-3

  <Desc / Clms Page number 39>

 by the reinforcement pallet 1873 in order to prepare the marking of the conductors 1800 according to the figures recorded by the recorder R-3. By the reinforcement pallet 1872 the relay
1870 opens the circuit of relays 1830 and 1840, these relays therefore releasing and at the same time opens the blocking circuit of the attracted recording relays of the R-2 recorder allowing these relays to return to their normal position.



  ¯The 1850 relay remains attracted by its blocking circuit comprising its lower winding and the armature pallet
1851.



   Similarly, the digits recorded on the R-3 and R-6 recorders are transmitted with suitable intervals between the pulse trains constituting the digits.



   When the dialer disconnection key, from the DK operator's sending keys, is operated after entering the necessary digits, the. conductor 1649 is earthed to attract relay 1580. Relay 1580 by attracting is blocked. by the armature pallet
1583 and earth to the rebar pallet 1572.

   In addition by the armature pallet 1582 the relay 1580 closes a multiple circuit for the relay 1520; by the normally closed contacts controlled by the armature pallet 1585, it opens the blocking circuit of the relay 1590, while by the front contacts of this armature pallet a second blocking circuit is established by the relay 1510 in series with the LFM electromagnet of the LF-1 line finder; and through the armature pallet 1583 it transfers the conductor 1507 from the earthed armature pallet 1596 to the upper coil of relay 1530. The upper coil of 1530 is then connected by the pallet d 'armature 1583, broom 1506, conductor 1507, rebar pallet 1711,

  <Desc / Clms Page number 40>

 
 EMI40.1
 the two windings of relay 1730 to the battery.

   Relay 1730 remains attracted to this circuit but due to the high resistance of its upper winding relay 1530 will not attract,
When switching relay 1590 of the selector of the transmitter SS-1 is de-energized, the DK send keys of the operator are disconnected from the brushes 1501-1504 of the switch of the transmitter by the armature paddles 1591-1594.



  In addition, relay 1590 disconnects conductor 1649 from the operator's DK sending keys via the armature pallet 1597 and at one point it opens the circuit of the pilot light 1500 of the transmitter 1 via the armature pallet 1598 producing some decrease in the illumination of the lamp, the circuit now including resistor R-3. This gives an indication to the long distance operator that the pulses leaving the logger transmitter are still being transmitted to the pulse circuit.



   By attracting relay 1870, fig. 18, the circuit of blocking relay 1850 drawn in series with recording relays A2 and D2 of recorder R-2 is opened by the armature pallet 1872 and therefore the Logger relays attracted A2 and D2 release and remove the blocking earth of conductor 1751. Since no other logger has been put into service, conductor 1751 is no longer earthed and relay 1720 released. Thereby the ground to the armature pallet 1723 is applied to the conductor 1755 and thus provides a shunt circuit of the relay 2080.

   The pulse circuit by wire 1508 is shorted by the armature paddle 1055 of the relay 2050, The relay 1720 opens at one point the initial circuit for energizing the relay 1740 by the armature paddle 1721 and by the 1722 armature pallet places a short on the high resistance top winding of relay 1730. This

  <Desc / Clms Page number 41>

 shunt circuit allows relay 1530 of transmitter circuit SL-1, Fig. 15, to pull in series with the lower winding of relay 1730. Relay 1730 remains engaged and relay 1530 locks by its winding ' lower and by the 1534 rebar pallet.

   Through the armature paddle 1531 the relay 1550 opens the loop of the circuit comprising the brushes 1522 and 1523 and connects the winding of the relay 1540 to the negative side of the junction line through the negative brush 1522 of the LF-1 finder circuit, conductor 1552 and cable2, negative 'and conductor / 771 of the junction circuit; the armature pallet 1523 it places a negative on the conductor EC via the resistor RI, the armature pallet 1513, the brush EC-1535, the conductor 1555 and the conductor 774 of EC; and by the armature pallet 1533 he prepares a circuit to place a ground potential on the conductor 1556 in order to attract .le -relay 680 of fig.6.

   Through the armature pallet 1535, the relay 1530 opens the circuit of the modeling lamp 1500 of the transmitter 1 to make it turn off in order to indicate to the operator that the digits that she has recorded have all been transmitted. As a further result of the opening of the circuit by the armature paddle 1535 the relay 1570 also releases after a short time interval and by the armature paddle 1572 opens the circuit of the delay relay on release 1560 which also relax. In addition to opening the 1560 relay circuit, the 1572 armature pallet opens the 1580 relay blocking circuits.



   When relay 1580 releases a circuit is established from ground to armature paddle 1581, armature paddles 1532, 1533 and 1514, brush 1526, conductor. 1556 ', wire 2, through the upper winding of relay 680, Note however that this circuit

  <Desc / Clms Page number 42>

 relay 680 is not established if relay 1540 is pulled and the circuit is open to armature pallet 1542.



  The relay 680 attracts and by the armature pallet 685 is blocked in series with the relay 1350, fig. 13.



   Moreover, the relay 1580 by releasing opens the circuit comprising the relays 1520 and 2040 by the armature pallet 1582 and these two relays release, by the armature pallet 1581 it disconnects the upper winding of the relay 1530 from the conductor 1507 thus allowing at relay 1730 to release at the same time it again prepares the electro SSM circuit; and by the armature pallet 1585 it opens the blocking circuit of relay 1510 which releases,
Releasing relay 1730 removes the earth potential applied to conductors 1750, 1752 and 1754 thereby releasing the attracted relays of figs. 18-21 inclusive. In addition, relay 1730 opens the blocking circuit of relay 1740 which also releases.



   The occupancy key BK shown in fig. 20 is provided so that a recorder transmitter can, if desired, be made "occupied" at the banks of the transmitter selectors, When the BK key is operated an earth applied the driver 1754 attracts the relay 1710. By / rear contact of the armature pallet 1711 the relay 1710 disconnects the relay 1730 from the conductor 1507 and through the front contact of the armature pallet 1711 it applies a ground potential to the driver 1507 thus preventing entry of the recorder transmitter by a recorder selector.



   Due to the slow release operation of relays 1560 and 1570, relay 1570 will first release and close a circuit through armature vane 1571 before relay 1560 has time to release. These relays are designed for

  <Desc / Clms Page number 43>

 connect the battery through resistor R2 to the positive conductor of the circuit loop so that a trunk line circuit relay automatically transmits the inrush current on the trunk line to signal to the far operator. However, since the described call was routed by an operator from a universal position, the establishment of the automatic call circuit of the rebar pallets 1561 and 1571 has no effect at this time.



   After all the digits recorded by the transmitter logger have been transmitted a ground is applied to the conductor 1556 to make the relay 680 attract. The relay 680 by attracting is blocked by its lower winding, the armature pallet 685 , the armature pallet 669, the conductor 1355 and the cable 1, the upper winding of the relay 1350 and the battery. Relay 1350 draws in series with relay 680 and the earth potential is removed from conductor 1304 by armature paddle 1351. 'When earth is removed from conductor 1304 relay 1620 draws in series with relay 1610 by the circuit comprising the conductor 1190. Through the armature pallet 1623, the relay 1620 prepares a circuit to cause the relay 1630 to attract this circuit being established when the next call is routed by the operator.

   Relay 1620 also opens the various control circuits of the SL-1 transmitter circuit, fig. 15, allowing the SL-1 transmitter circuit and the transmitter recorder connected to it to return to their position. normal. Another effect of the attraction of relay 680 is to multi-circuit for lamp 603 through armature paddle 686. Direct relay 680 also places a ground potential / on the 0-773 conductor of the associated selector. TFS-1, through armature pallets 681 and 682 it closes the talk circuit and through armature pallet 684 it connects lamp 601 to conductor EC774.

  <Desc / Clms Page number 44>

 



   When the SL-1 transmitter circuit, fig, 15, has returned to rest, the brushes of the LF-1 finder circuit are disconnected and the bridge between the positive and negative conversation conductors of the junction circuit shown in figs. 6 and 7 is open.



   Operation of the first TFS-1 long distance selector.



   Let us now refer to the first indoor selector TFS-1, fig. 7, the conductor C773 was grounded by the attraction of the relay 1510 of the circutt of the transmitter SL-1, fig, 15, This has the effect of 'applying an earth to the lower winding of relay 710 and pulling relay 730. Relay 730 prepares a circuit for the GREEN ascension electro- and also a blocking circuit for its lower winding by the pallet armature 732, it opens the circuit of the rotation electromagnet ROT through the armature pallet 733 and through the armature pallet 731 it connects the brush C of group 770 to the lower winding of the relay 740.



   When relay 1520 of the SL-1 transmitter circuit, fig, 15, establishes a circuit loop through the armature paddle 1521, the relay 710 attracts by: battery, upper coil of relay 710, fig. 7, armature paddle 741, negative conversation conductor 771, conductor 1552 and cable 2, negative brush 1522 of LF-1 finder circuit, normally closed contacts controlled by armature paddle 1531, armature paddles 1521 and 1511, positive brush 1525, conductor 1553 and cable 2, positive conversation conductor 772, armature pallet 742, lower coil of relay 710 to grounded conductor C773.



  Relay 710 establishes a circuit through armature paddle 711 to relay 720 from ground to paddle

  <Desc / Clms Page number 45>

 armature 746. The release relay 720 attracted by this circuit and by the armature paddle 723 makes an additional application of ground to the conductor C773 and it energizes the bias winding of the relay 740 through the armature paddle 722.



   On receipt of the first series of pulses, relay 710 circuit is momentarily interrupted by pulse contacts 1521. When relay 710 releases after the first digit 1, a circuit is established from earth to the paddle. armature 746, armature pallet 711, armature pallet 724 and its front contacts, armature pallet 732, the winding of the GREEN ascent electromagnet to the battery and a branch of the circuit passes through the lower winding of relay 730 to the battery.



   The brushes 770 are therefore raised one step by the operation of the vertical GREEN electromagnet. Head contacts 751 and 752 prepare circuits for the rotation solenoid ROT and release solenoid RLSE, respectively, while the head contacts 750 open the initial circuit of the top winding of relay 730 to to allow relay 730 to release at the end of the trains of pulses transmitted to the GREEN ascending electromagnet, the lower coil of the relay being sufficient to keep the relay attracted for the duration of the trains of pulses.



   When relay 730 releases at the end of the first digit it disconnects its own lower winding and the GREEN ascending electromagnet by the armature paddle 732, it connects the test winding of relay 740 to brush C by the armature pallet 731 while by armature pallet 733 it establishes an anti-switch circuit for the rotation electromagnet ROT through the head contacts 751 the armature pallet 711, 710, and earth to the pallet 746 reinforcement

  <Desc / Clms Page number 46>

 relay 740. The ROT rotation electromagnet then functions as a buzzer to rotate the brush 770 on the pads of the chosen level in search of a free junction leading to the requested trunk line selector.



   Operation of the TLS-1 trunk line selector.



   When a free selector is reached either selector TLS-1 in fig. 9, the test winding of relay 740 of selector TFS-1 meets a negative potential given by brush C of brush group 770 and conductor C914 of the TLS-1 selector, fig. 9, which is obtained through the head contacts 991 and the upper winding of the relay 930. The relay 740 attracts and through the armature paddle 746 opens the circuit of the rotation electromagnet ROT and also of the relay circuit. 720.

   In addition, relay 740 extends the incoming conductor EC774 to the EC brush of brush group 770, through the armature paddle 743 it gives an earth potential through brush C of brush group 770 via the normally closed contacts of the armature pallet 731 and by the same operation short-circuits the upper winding of the relay 740, while by the armature pallet 745 it establishes a circuit for the middle or guard winding to block the relay in its position of attraction by the incoming conductor earthed C773 and by the armature paddles 741 and 742 it disconnects the conversation conductors 771 and 772 from relay 710 and extends them to the positive brushes of the brush group 770. The relay 710 then releases and prepares a circuit for the RLSE releasing solenoid through the armature pallet 711.

   The relay 720 therefore returns to its normal position by opening the test winding of the previously shunted relay 740, opens the excitation circuit of the polarized winding of the relay 640 through the armature paddle 722 and removes the locally applied earth. coming from the stray conductor C by the

  <Desc / Clms Page number 47>

 
 EMI47.1
 rebar pallet 723 by abandoning the conouotor grounded by rebar pallet 1512.



   The TLS-1 trunk selector, fig. 9, having been chosen the relay 930 is energized by the conductor 914 through the head contacts 991 and its upper winding and the relay 910 is energized by the circuit comprising the positive and negative conductors 912 and 913 and the impulse contacts 1521. -The relay 920 attracts following the operation of the relay 910 by the following circuit: earth to the armature pallet 987, armature pallet 911 and winding relay 920 to the battery. When pulling relay 930 a circuit is established by armature paddle 932 to operate relay 940. This circuit is established from conductor 914 through shaft contacts 997, the armature pallet 932 and the winding of relay 940 towards the battery.

   In addition, the relay 930 prepares a circuit through the armature pallet 933 for its lower winding in multiple with the vertical GREEN electromagnet. As a result of the pull of the relay 920 a circuit is prepared by the armature paddle 921 for the test winding of the relay 980, a circuit is established by the armature paddle 922 for the energization of the winding biasing of relay 980, through armature paddle 923 an additional earth potential is applied to conductor C-914 and through armature paddle 924 the multiple circuit for the lower winding of relay 930 and the electromagnet VERT climb is prepared.



   Referring again to the attraction of relay 940, it opens through the armature pallet 941 the circuit of the brush C of the broom group 990, through the armature pallet 942 it establishes a multiple circuit for itself through the 'intermediate the reinforcement pallet 961, through the reinforcement pallet 943,

  <Desc / Clms Page number 48>

 it disconnects the BC brush belonging to the brush group 990 from the active winding of the relay 970 and by the armature paddle 944 prepares a bridge for the circuit of the rotation electromagnet ROT. When the second stored digit (digit 3) is transmitted, relay 910 is momentarily de-energized three times and the vertical GREEN solenoid operates each time.



  The lower coil of relay 930 keeps the relay energized after the upper coil has been disconnected by the head contacts 991 during the first step made by the switch. The head contacts 992 and 993 are thus closed during the first step of ascent of the switch to prepare the circuit of the release electromagnet RLSE and of the rotation electromagnet ROT. Following the 3 pulses transmitted to the line relay 910, the relays rise to the third level.



   Shaft contacts 997 are open when brushes 990 are at the level of the third level since these contacts are only open for the levels reserved for groups of junctions that can be obtained by a single number and remain closed for all levels for which the junction groups are chosen by a 2-digit number.



   At the end of the pulse trains, relay 930 releases and opens the initial circuit for excitation of relays 940 by the armature pallet 932.In addition, since the shaft contacts 997 are open, the blocking circuit of relay 940 is open and the relay releases and prepares a circuit for the rotation electromagnet ROT by the armature pallet 944 and also connects the test winding of the relay 970 to the brush BC of the brush group 990, it opens the relay circuit 950 at the front contact of the armature pallet 944 and by the armature pallet 941 connects the brush C of the brush group 990 to

  <Desc / Clms Page number 49>

 the test winding of relay 980.



   As soon as the relay 940 releases and closes the rear contacts of the armature pallet 944 an auto-switch circuit is established for the rotation electromagnet ROT by the following circuit: earth, armature pallet 987, armature pallet 911 , closed contacts of the head contacts 993, auto-switch contact 996 of the rotation solenoid ROT, armature pallet 944, normally closed contacts controlled by the armature pallet 964, winding of the rotation solenoid ROT , to the battery.



   The rotating electromagnet attracts to the. way of a buzzer and rotates the 990 brushes on the requested trunk group bank contacts.



   Let us now suppose that the TL-1 trunk line, fig.l and 2, is free when the brushes 990 arrive on the pads 275 of the bank associated with the TLS-1 trunk selector of the chosen level. Relay 980 will attract by the following circuit: battery, winding of relay 290 of fig. 2, armature paddles 283 and 245, conductor C278 of the stud group 275, brush C of brush group 990, armature paddles 971.965, 951.941, normally closed contacts controlled by armature paddle 931, armature paddle 921, relay test winding 980, to conductor C914 grounded.

   While waiting for relay 980 'stops the rotational movement of the brushes and opens the excitation circuit of relay 920, it establishes a blocking circuit for its middle winding by the armature pallet 986, it disconnects the brush BC from the relay'970 by the armature paddle 985, it connects the incoming conductor EC915 to the EC brush of the broom group 990 through the armature paddle 984, it applies a direct earth potential to the brush C of the broom group 990 by the reinforcement pallet 983 for

  <Desc / Clms Page number 50>

 keep TLC and it transfers the incoming positive and negative conductors 912 and 913 respectively from the windings of the relay 910 to the positive and negative brushes of the brush group 990 respectively, through the armature paddles 981 and 982.



  Earth at armature paddle 983 also places a shunt on the test winding of relay 980 but the relay remains attracted to its blocking circuit.



   Relay 910 releases and closes the RLSE release solenoid circuit at one point. The TLS-1 trunk selector is held in its attractive position by the earth potential supplied by conductor 914 and coming from the previous first TFS-1 trunk selector, fig.7.



   Operation of the TLC circuit of the trunk line,
In the trunk line circuit TLC, fig. 2, the relay 290 is attracted by the circuit indicated above and by the armature pallet 293 connects the conductor 278 to the pad 297 and its multiplication to occupy the trunk line circuit In addition, the relay 290 opens the starting circuit at one point by the armature pallet 295 and by the armature pallet 294 it opens at a point the circuit through which the relay 280 is blocked locally. during an incoming call, the conductor 279 is then connected through the lower winding of the relay 280 to open contacts while the negative and positive conductors 276 and 277 are respectively connected to a ground potential via the windings of relay 220.



  This is the condition for which the calling line tests empty.



   Circuit test. When relay 1550 draws into the SL-1 transmitter circuit, it connects a ground potential across the winding of relay 1540 and through the armature paddle 1531 to the negative conversation conductor in order to test a

  <Desc / Clms Page number 51>

 negative potential.

   In the communication described above the negative and positive conversation conductors have been connected to earth and therefore relay 1540 does not attract,
However if the line relay of the first trunk selector or the trunk line selector is still connected to the terminals of the talk leads, the negative talk lead will have a negative battery potential which will be applied to it through the coil of the relay. line connected and relay 1540 draws in series with the connected line relay and through the armature pallet
1542 prevents the IC conductor from being grounded. Relay 680 is therefore prevented from being drawn and the associated switch train cannot be connected to seeker F-1.



   In addition by the armature pallet 1543 an earth is applied to the coil of the relay 1570 to prevent its release and also to make the lamp 1500 illuminate.



   The attendant is informed that the communication has not been fully established and resets her K-1 conversation key, thereby releasing the SL-1 transmitter circuit, fig. 15, and the switches in the working position controlled by the operator. recorder-transmitter equipment.



   Manual call.



   When the long distance operator is warned by the extinction of the lamp 1500, fig. 15, that the communication has been established. to a trunk line of the desired group, momentarily. it operates / its key to unstable position K-13 thus establishing a circuit through contacts 1422 to attract relay 1320, fig.15. By the armature pallets 1321 and 1322 the relay 1320 connects the conductors 656 and 655, respectively to the contacts 1421 and 1420 of the key K-13.



   Therefore when contact 1421 of key K-13 is

  <Desc / Clms Page number 52>

 closed, a momentary call control pulse is transmitted from the negative pole of the office battery through resistor R7, contact 1421 of key K-13, conductor 1446, armature paddle 1321, conductor 656 and cable 1, the reinforcement pallet 673, the reinforcement pallet
682 to the positive conversation conductor 772. At the same time this application of the negative potential to the conversation conductor takes place, a ground being applied to the negative conversation conductor via the contacts
K-13 key 1420, conductor 1447, reinforcement pallet
1322, conductor 655 and cable 1, the reinforcement pallet
671,

   the armature pallet 681 towards the negative conversion conductor 771. This last condition prevents any possibility of unwanted operation of the relay 240 by the negative conversation conductor and by induction through the capacitor associated with the windings on the side of the table of the translating reel 200.



   In the TLC trunk line circuit, Fig. 2, the momentary call control pulse has the effect of operating relay 230 through the lower winding of coil 240 and armature pallet 244 of the relay 240. On pulling relay 230 applies a ringing current of selected frequency to trunk line TL-1 and coming from common call conductor 296.



   Control of the artificial interurban line of complement.



   It is common practice to provide an artificial complement line at each end of the central office side of a trunk line with repeater such as artificial line 21. This artificial line consists of two resistors in series with center tap and a shunt resistor connected to the center taps and in series with an isolation capacitor.

  <Desc / Clms Page number 53>

 



   When the TL-1 trunk line, fig. 2, is in service and relay 290 is therefore drawn, a circuit is closed by the armature pallet 291 through the armature pallet 221 of the relay 220 through the winding of relay 210 to the battery. Relay 210 attracts unless relay 220 is attracted.



  Relay 220 is drawn to the terminated trunk line. sant at the table and through a simplex circuit provided there is a connection made to the conversation conductors connected to the trunk line. Each of these circuits used to connect the trunk line to the local line is provided with a 44000 ohm center tap resistor through which current is applied to operate the control relay of the artificial line.

   One of these artificial line control resistors is connected to the windings, table side, of the translator coil 500 of the OLR circuit, fig. 5. The current flowing through relay 220 is supplied by one of the resistors and with the middle taps indicated above / is insufficient to attract relays 240 and 230, neither of which is as sensitive as relay 220 and each of them being only crossed by half of the current flowing through relay 220.



   The long distance operator can manipulate the K-5 key to disconnect the called side of the call while she is talking on the TL-1 long distance line if she wishes.



   Likewise it operates the K-15 key if it wishes to converse with the called side of the communication without being heard by the calling side.



   When the operator operates her K-13 key and relay 1320 attracts, conductors 656 and 655 are disconnected from conductors 1180 and 1181 to prevent the potential

  <Desc / Clms Page number 54>

 
 EMI54.1
 of the battery through the 44,000 ohm resistor 2 of the artificial line is connected to conductors 656 and 655. Therefore relay 220 is not attracted at this time. The relay 210, fig.2, is attracted by an earth given by the reinforcing pallet 291. By the reinforcing pallets 211, 212 and 213, the relay 210 disconnects the artificial line 214 of the conversation conductors of the junction.

   The inrush current is then transmitted over the TL-1 trunk line through the translator coil 200 to recall the operator located at the far end of the TL-1 trunk line.



   The long-distance operator from the central office operates the K-13 key only momentarily and therefore the call control impulse only causes momentary operation of relay 230. In addition, relay 1320 fig.



  13, again connects leads 656 and 655 respectively to leads' 1180 and 1181 from the position terminating at the operator's telephone set. The potential of the battery through the 44,000 ohm control resistor of the reserve line is again connected between conductors 656 and 655 via the closed contacts of the armature paddles 1321 and 1322. this takes place the relay 220 is energized by this simplex circuit as described above. Through the armature paddle 221 the relay 220 opens the circuit of the relay 210 which immediately drops and the artificial line 214 is connected to the new / talk leads of the junction.



   If the first application of the inrush current transmitted on the TL-1 trunk line does not elicit a response from the remote operator, the trunk operator can again transmit an additional pulse of

  <Desc / Clms Page number 55>

 inrush current having the same effect as indicated above.



   When the remote operator answers she is informed of the called number and establishes the call in the usual way and when the long distance operator at the central office hears that the called subscriber answers, she marks the long distance card to indicate the moment when started the conversation between the calling and called subscribers.



   The long distance operator at the central office then restores her K-1 key to its normal position and thereby opens the guard circuit of relay 670 through contacts 695, the initial circuit for energizing relay 670 through contacts 696. and through the normally open contacts 694 disconnects the lamp 601 from the conductor 1358 and connects it to the office battery through the normally closed contact 694.



   When relay 670 releases relay 1130 from equi-. the operator position, fig. 11, also releases. As a result of the de-energization of relay 670, the conversation conductors of the calling subscriber are extended to the called subscriber through the normally closed contacts controlled by the armature paddles 672 and 674 consequently disconnecting the telephone circuit of the operator of the calling and called lines. Via the armature paddle 676, the relay 670 disconnects the battery potential of the conductor 608 thereby causing the release of the relay 1340, fig. 13, and through the armature paddle 677 it opens the circuit of the relay 660.

   Relay
1350 was energized in series with the lower winding of relay 680 but the latter remains blocked by the circuit comprising resistor R5 and the battery through the armature pallet 685 while relay 1350 releases. Releasing relay 660 opens the circuit (see continued on page 55 bis)

  <Desc / Clms Page number 56>

 the upper winding of the relay 650 by the armor pallet 662 and disconnects the earth of the polarization windings of the relays 610 and 620 and by the same operation causes the excitation of the lamp 360. By the pallets of armature 664 and 665 relay 660 transfers lamp 602 from control of relay 1370 to the lower winding of relay 650 and to conductor C-1 of brushes 618. Relay 650 remains in series with the lower winding of relay 320, fig.5.



   As a result of the de-energization of relay 1130 of the attendant position and of relays 1330, 1350, 1370, fig. 13, the equipment of the operator position returns to its normal position.



   After key K-1 is returned to its normal position and relay 670 has released relay 220 of the trunk line circuit in fig. 2 is drawn through the 44,000 ohm control resistor of the artificial line. circuit and the battery placed in bridge on the windings on the switch side of the translator coil 300 of the CLR junction circuit of fig. 3.



   The calling and called subscribers can converse with each other even when the K-1 key has not been returned to its normal position, the conversation circuit closing via the closed contacts of relay 670 through the operator position relay in fig. 15 before key K-1 is returned to its normal position and after it is returned to this position the conversation conductors of the junction are normally extended by contacts closed controlled by relay 670.



   Supervision signal by the station fork contact. of the local automatic subscriber.



   If the local calling subscriber of set A wishes to attract

  <Desc / Clms Page number 57>

 the attention of the interurban operator of the central office it can 'do it by actuating its contact of fork momentarily one or more times. Each time its fork contact is actuated the junction circuit TC of fig. 1, is put into operation in the manner, well known to return the application of the potential to the two conductors of the junction T-1 thereby reversing the current flowing through the lower winding of the relay 340 and the upper winding of the relay 330 of the CLR junction circuit of fig. 3. Whenever the current is,

  inverted relay-330 attracts to introduce a high resistance R in the circuit of relay 320 and the associated conductor C being extended to the terminals 360 of the finder benches, fig. 6, for the duration / reversal of the current. Note that the resistor R and the resistance of the upper winding of the cut-off relay 320 are normally shunted by the armature paddle 331 of the relay 330. Therefore when the relay 330 attracts, the battery through the two coils of relay 320 and / resistor R is connected through armature paddle 341 to conductor C going to terminals 360 of the researcher benches, fig. 6, thereby reducing the current sufficiently for relay 650 to operate between certain limits relaxes.

   By releasing relay 650, fig. 6, establishes a circuit from earth to armature pallet 634, armature pallet 652, normally closed contacts controlled by armature pallet 664, lamp 602 to
The dotted connection battery / jumper 653, comprising the armature pallet 651 and which bypasses the lower winding of relay 670 is not used in the CLR or from contact to contact in the operator position and has no influence on the operation of the circuit at this time.

  <Desc / Clms Page number 58>

   When the current flowing through T-1 is restored in the normal direction, relay 330 releases and again bypasses resistor R and the upper winding of relay 320 through armature pallet 331.

   Relay 650 draws in series with the lower coil of relay 320 and opens the ignition circuit of lamp 602 through armature vane 652.



   Following the flashing of the lamp 602, the attendant can again operate the key K1 to activate the relays 1130, 670 and 660 and to connect the conductors 1180 and 1181 to the calling line. When the attendant has responded to this signal and has conversed with the calling subscriber, she can reset key K-1 again to release relays 1130, 560 and 660 and disconnect the conversation conductors from her position, or else she may abandon the established call and establish another in the event that it finds that the first call has not been established with the called line requested.



   Supervisory signal by callback from the called trunk line.



   If the remote operator connected to TL-1 wishes to put in communication with the long distance operator who made the call, she momentarily applies the inrush current to TL-1 to attract relay 270 and open the circuit normally. closed relay 260.



   Momentary de-energization of relay 260 establishes a circuit from earth to armature vane 246, armature vane 261, the upper coil of relay 280. Relay 280 is blocked by armature vane 284 in series with relay. EC-279 driver, the EC brush of the 990 brush group, the armature paddles 984 and 962, the EC-915 driver and the bench stud of the first interur-

  <Desc / Clms Page number 59>

 previous bath, EC broom of broom group 770, reinforcement pallet 744, conductor EC-774, reinforcement pallet
684, the lamp 601, the contact 694 of the key K1 to the battery. Lamp 601 is continuously illuminated by this blocking circuit to warn the operator.

   When the operator responds by operating the key Kl the relays 1130, 670 and 660, at the same time as the other relays of the circuit of the operator position will attract and connect the conductors 1180 and 1181 to the conductors 656 and 655 going to the operator called by TL-1. Disconnecting the lamp 601 by operating the key K1 opens the blocking circuit of the relay 280 which immediately releases and the lamp 601 goes out.



   During the operation of the relay 280, a circuit is established by the armature paddle 281 to block the relay 290 and to maintain a ground on the conductor 0 going to the researcher benches, FIG. 6, and by the armature paddle 283 an earth is applied to the conductor C of the T-4 junction to occupy the junction to the researcher benches When the operator operates her key K-1 to connect the conversation conductors from its position at the TL-1 talk leads the 601 lamp circuit is transferred from the battery to the normally closed contacts 694 of the K-1 key, to the normally open contacts 694 thereby setting the lower winding relay 280 and lamp 601, in series with high resistance 1303, and the winding. of relay 1300.

   This additional resistance causes relay 280 to drop since its guard winding effectively acts only within certain limits. When the remote attendant has established her communication with the interurban operator at the central office, the latter sets her K-1 key in its normal position.



   Clearance of a call on the calling side.



  * When communication is established, hang up the

  <Desc / Clms Page number 60>

 receiver at the local calling station A causes relay 330 to attract resistance R and the resistance of the upper coil of relay 320 in conductor C connected to the researcher benches. The relay 650 is released to make the lamp 602 illuminate permanently as a communication end signal.



   It is understood that when the operator releases a searcher all the conversation keys of the other searchers associated with this position must be in the normal position while the conversation key K-1 of the searcher to be released must be operated at the same time as the K8 key or K-1 key can be operated first, K-8 key then. When key K-1 is operated, relay 370 is attracted by conductor 604 and is blocked by means of its upper winding in series with the winding of relay 1130.

   In addition conductors 653 and 654 are connected to conductors 1180 and 1181, relay 630 is kept drawn in series with relay 1340, relay 660 is attracted by the grounded starter conductor 1302 and relay 1350 draws in series with the lower coil of relay 680. Relay 660 establishes an obvious circuit for relay 650.



   The attendant then momentarily operates her key K8 to cause relay 1310 to be attracted by grounded contacts 1409 of key K-8. The relay 1310 disconnects the conductors 653 and 654 from the conductors 1180 and 1181 by the reinforcement pallets 1311 and 1312 and by this same operation disconnects the conductors 653 and 654 from the conductors 656 and 655 to prevent the operator and the called subscriber from receive unpleasant "clicks" in their receiver while releasing the switches.

   Using contacts 1408, the K-8 key earths the 608 conductor, which has the effect of

  <Desc / Clms Page number 61>

 to bypass relay 1340 and remove the shunt from the upper coil of relay 630,., The blocking circuit of relay 630 which includes the earth through its upper winding, the head contacts 635, the springs are to encumber / 646, the armature pallet 632, the resistor R4 and the battery, is short-circuited when the conductor 608 is grounded by the operation of the key K-8. Relay 1350 remains attracted however and when relay 1340 releases the circuit established by armature paddle 1343 to cause relay 1170 to attract is not closed because its circuit is opened by armature paddle 1351 of relay 1350.

   In this way further incoming calls cannot be received and further operation of the transmitter control relays is prevented.



   When relay 1340 de-energizes the earth at armature paddle 1344 is removed and relay 660 releases to remove the earth from the bias windings of relays 610 and 620 and also to remove the earth from the EC-1 brush of the group. broom 618 so that the lamp 360 goes out. Via the armature pallet 662 the relay 660 opens the de-energizing circuit of the upper winding of the relay 650 which thereby releases. Following the de-energization of relay 630 the earth at the armature pallet 634 is removed from the middle winding or 'relay blocking winding' 610 and brush C-1 of brush group 618 to allow relay 610 to release.

   Through armature pallet 631, relay 630 establishes a circuit from earth, armature pallet 631, armature pallet 661, head contacts 647, the coil of the release solenoid RLSE to the battery. The shaft brushes are then returned to their normal position. When the K-8 key is restored to its normal position after

  <Desc / Clms Page number 62>

 having been actuated momentarily the relay 1310 returns to its normal position and again connects the conductors 633 and 654 to the conductors 1180 and 1181 which has no effect on the circuit at this time because the calling side of the communication has been released by the return to rest of the researcher F1.

   Relay 1340 has released, relay 1350 remaining pulled in series with relay 680 as long as key Il-1 remains in its working position.



   In the CLH circuit of fig. 3, relay 320 releases when the earth potential is removed from the conductor and by the armature pallet 321 removes the shunt of the high resistance upper winding of relay 340. This one gives supervision of the disconnection of the TC junction circuit, Fig, l, The relay 310 is not attracted at this moment because it is disconnected by the armature pallet 332 of the relay 330. As soon as the usual operation of the relay takes place in the TC junction circuit switches OS-1 and 1-3. (shown in Fig.l) release and the conductors of the T-1 junction are disconnected so that the current no longer flows there. When this happens, relay 340 releases.

   Relay 330 releases when its bias circuit is opened by armature paddle 342 by de-energizing line relay 340.



   Before releasing the called side of the call because of the end signal, the trunk operator at the trunk table in the central office can momentarily return inrush current to TL-1 by operating the K-13 key. . This will signal the remote operator to send a release call signal.



   If the called subscriber of the remote long distance office has hung up his receiver and the attendant has therefore received a release signal, she sends a inrush current

  <Desc / Clms Page number 63>

 on TL-1 to cause the operation of relay 270 of the trunk line circuit shown in fig. 2. The operation of this circuit due to the transmission of an inrush current by the remote operator is finally summed up by the lighting of the lamp 601. After having taken note of the end signal the long distance operator can either speak to the remote operator or she can assume that the illumination of the call lamp 601 is an end signal and operate the key K12 to restore the called side of the communication to its normal position.



   The called side of the communication is released due to the momentary operation of the K-12 key. Due to the closing of the contacts 1419 the earth is connected via the conductor 1348 to the winding of the relay 1320; this relay when operating disconnects the conductors 655 and 656 from the conductors 1180 and 1181 to prevent the operator from receiving unpleasant "clicks" in her receiver. through contacts 1418, the key K12 connects an earth through conductor 1355 to keep relay 1350 drawn and to place a shunt on the blocking winding of relay 680 of finder F-1. The K-1 key is operated during the time that the long distance operator releases the calling and called sides of the connection and is re-established after the called side of the connection is released.

   Relay 680 releases when its blocking or bottom winding is bypassed, disconnecting from it. makes the conductors 771 and 772 of the reinforcing pallets 681 and 682; it removes the blocking earth from conductor 0773 at armature paddle 683 and it disconnects lamp 601 from conductor EC-774 at armature paddle 684 and through armature paddle 686 opens the circuit of lamp 603 to indicate that the F-1 finder is available for others

  <Desc / Clms Page number 64>

 calls, when the key K-12 is returned to its normal position, relays 1320 and 1350 return to their normal position.

   If the long distance operator wishes to release the called side of the call before she has received an end signal from the remote operator, she can first momentarily operate the K-13 key to cause the sending of inrush current. on TL-1 to give the remote operator a release call signal. The long distance operator then operates the K-12 key to release the equipment. If the long distance operator is not busy establishing other calls, she can leave the K-1 key in its working position in order to make the F-1 finder available for other calls.



  If this is the case, de-energizing relay 1350 has the effect of making relay 1170 re-attracted. This removes the occupancy potential of conductor 1188 to mark the operator position "free" on the test relays of the distributor. and to place a ground on conductor 1189 to turn on the distributor to connect the operator position and the chosen finder to a free transmitting recorder by means of a free transmitter circuit.



  Referring to the first inter-city selector, de-energizing relay 680 releases relay 740 because the blocking circuit by its middle winding is disconnected by removing the earth at conductor C-773. A circuit is then closed by ground to the armature vane 746, the armature vane 711, the armature vane 724, the head contacts 752, the coil of the release solenoid RLSE, to battery. The brushes 770 are therefore returned to their normal position.



   In the TLS-1 trunk line selector, relay 980 releases when the previous selector removes the ground potential of conductor C-914. By releasing the

  <Desc / Clms Page number 65>

 relay 980 disconnects negative, positive and EC brushes from brush group 990 and removes ground from brush C through armature paddle 983. Through armature paddle 987 relay 980 establishes an operating circuit of the RLSE release electromagnet via the armature paddles 911 and 924 of the de-energized relays 910 and 920 and the head contacts 992. The brush group 990 is therefore returned to its normal position.



   In the TLC trunk line circuit, fig. 2, the removal of the ground potential of the conductor C-278 by the preceding switch makes the circuit accessible to the other selectors and allows the relay 290 to release and put the circuit under normal conditions.



   Congestion situation at the first long distance selector.



   If the first TFS-1 trunk selector cannot find a free junction on the desired level, the rotation of brushes 770 continues until the brushes advance to the out-of-position position. Blanking contacts are provided on the broom bank C of broom group 770 and a counter is preferably connected to each of these contacts to record the number of unsuccessful attempts to find a free junction in the group. The test winding of relay 740 draws in series with the meter and applies a ground to brush C to operate the occupancy meter.

   At the same time the congestion contacts 753 are closed and connect the upper winding of relay 730 into the circuit to provide an effective source of potential for operation of relay 740 if the occupancy meter is high. resistance. When relay 740 establishes a bypass on its test winding to apply an earth potential directly to brush C, relay 730

  <Desc / Clms Page number 66>

 is attracted and by the reinforcing puck 731 modifies the connection of the earth potential to the brush C of the reinforcing pallet 722 of the relay 720.

   By this arrangement when the relay 720 releases following the operation of the relay 740 and the release of the relay 710, the earth is disconnected from the brush C of the brush group 770 in order to leave the occupancy counter without the possibility of being pressed before the TFS selector returns to idle. Relay 730 remains attracted through the coil of relay 740 by a ground given by the incoming conductor C-773. connect
In addition, the encumbrance contacts 754: / the conductor of the switch device at sixty pulses per minute which is associated with it with the associated conductor EC-774 in order to form a circuit making the lamp 601 flash and characteristic of all the junctions occupied when relay 680 attracts.

   The TFS-1 long distance selector creamer is released as previously described when removing the ground potential of the incoming conductor 0-773.



   Congestion situation at the trunk line selector.



     Com..e indicated by the connection bar 287 in dotted lines of FIG. 2 the pads B and C of the last trunk line in the group are connected together to provide a circuit to actuate relay 970 if the last trunk line of a particular group is also busy.



  In addition the conductor C is earthed thus preventing the relay 980 to attract when the brushes 990 advance to the last junction of the group. The test winding of relay 970 is excited by an earth potential given by the conductor C-178 and by the intermediary of the bar 287, the brush BC of the brush group 990, fig. 9, the armature paddles 985, 963, 943 of the de-energized relays 980,960 and 940 to the upper or active winding of the relay 970.

  <Desc / Clms Page number 67>

 



  The bias winding of relay 970 is energized by the grounded conductor 914. Pulling relay 970 disconnects broom C from broom group 990 to prevent further operation of relay 980 as the brooms pass rotating on trunk lines of subsequent groups of the level. By this operation it is ensured that the self-interrupting circuit of the rotation electromagnet which causes the brushes to move step by step will remain established until the brushes reach the eleventh position of rotation.

   When this occurs, congestion contacts 994 are closed to attract relay 980 to complete the movement of the rotation electromagnet ROT and to operate relay 930 such that the count pulse momentary will be provided as explained with respect to the first toll selector. Note also that the jammed contacts 995 are closed to connect the sixty pulse per minute interrupter lead to the associated incoming lead EC-915 to produce flashing of lamp 601 when all junctions are occupied. The selector is released in the usual way. is
The test winding of relay 970 / higher resistance than the test winding of relay 980.

   If, therefore, the last trunk line of the group is guarded by a relay analogous to the guard relay 240 of the trunk line circuit TLO, fig. 2, the current flows through these two test windings in series and this current rises to the operating current in the winding of relay 970 before it reaches the operating current in the winding test relay 980. Relay 970 quickly pulls in and disconnects relay 980 before relay 980

  <Desc / Clms Page number 68>

 had time to draw in series with the test winding of relay 970.



   Guard of a defective trunk line.



   If the TL-1 trunk line is seized and found to be defective, the operator can keep this trunk line against another seizure and report it to the test station by
K-1 maneuvering his key K-14 tanais that the key / is in the working position. By the momentary operation of the key K-14 a circuit is established starting from the earth at the springs 1425 to operate the relay 1520 through the conductor 1448. By the armature paddles 1321 and 1322 the conductors 656 and 655 are disconnected from conductors 1180 and 1181 and conductors 653 and 654.

   By the springs 1424 of the key K-14 the potential of the battery by the intermediary of the resisted this R-1, the conductor 1447, the conductor 655 and the cable 1, the armature pallets 671 and 681, is connected to conductor 771, negative conductor 912, negative 276, shock coil upper winding 250, relay lower winding 240, and relay winding 220 to ground. Relay 240 attracts and locks by its top coil and frame pallet 245 in series with lamp 217 of test panel 216.

   Relay 240 also disconnects relay 230 through armature paddle 244, through armature paddle 245 it opens conductor C of junction T-4 to prevent seizure of trunk line circuit and paddles of reinforcement 241 and 242 it connects the common guard tone conductors to the conversation conductors of the TL-1 trunk line to place a tone on this trunk line which can be heard

  <Desc / Clms Page number 69>

 if the trunk line is seized at the far end to indicate that it is defective and will be kept in a similar fashion at the far end - ..

   When the trunk line is repaired the relay 240 can return to idle by opening its blocking circuit with the key K-18 of the test panel 216 from which it follows that the lamp 247 is extinguished.



   Call coming from a long distance line to a local automatic office N 8.



   Now suppose that a subscriber of a remote network calls the subscriber of station A and the call is received by trunk line TL-1 which terminates at trunk line TLC circuit of FIG. 2.



   When the TL-1 trunk line is seized by the remote office and inrush current is sent to that line, relay 270 is actuated and thereby opens the relay 260 drive circuit. On releasing, the relay 260 closes a drive circuit for the top winding of relay 280. Relay 280 establishes a blocking circuit for its top winding from earth to the armature pallet 284, the armature pallet 294, the armature pallet 294. - upper bearing of relay 280, towards the battery. Relay 280 places an earth potential on conductor C of branch junction T-4 through armature pallet 283 to occupy the trunk line and also to remove the potential indicating "free" from the relay winding. 290,, To the rear contacts of the armature pallet 283.

   Through the armature paddle 282 the relay 280 connects the potential of the battery through the winding of the relay 290 to the conductor C going to the researcher benches and through the armature paddle 285 applies a ground to the conductor 286 to start the searcher in order to search for the calling line.



   We will assume that an operator at a table position has operated her KL-1 key to choose a free finder

  <Desc / Clms Page number 70>

 and thereby marked its position as "free" on the dispenser test circuit and its position was therefore chosen by the dispenser to respond to this call.



   It will be assumed that the calling line is connected to the banks accessible by negative 2, positive 2, brushes C2 and EC2 of group of brushes 618. Consequently when these brushes come into contact with pads 297 a circuit is established for the winding test of relay 620 in series with relay 290 of the trunk line circuit by the following route: when winding relay 290, armature pallet 282, pin C-297, brush C2 of brush group 618, winding relay 620, armature paddle 613, relay lower winding 650, armature paddle 634 to earth. Relay 620 attracts and extends the response side of the equipment from the attendant position to the calling trunk line circuit via brushes N 2 of brush group 618.

   Relay 620 locks by its guard winding to armature pallet 624 and by the forward contact of armature pallet 623 shunts its test coil such that when earth is returned to the brush C2 through the trunk line circuit, this earth is placed directly on the lower winding of relay 650.



   In the trunk line TLC-1 circuit, relay 290 is blocked by armature paddles 293 and 292 and earth at armature paddle 281. Earth at armature paddle 281 is directly connected by 'intermediary of the reinforcing pallet 292 at the stud C of the studs 297 of the researcher's bench and with the studs which are multiplied there to occupy this trunk line circuit.



  By means of the armature pallet 295 the relay 290 opens the starting circuit and by the armature pallet 294 it opens

  <Desc / Clms Page number 71>

 the blocking circuit of relay 280 which releases.



   Earth is now connected to the C2 brush of finder F-1 through the armature paddle 634 of the relay 630, the lower winding of the relay 650, the armature paddle 723 and the brush group 02 brush 618, goes through the conductor C of the contact group 297 and the armature pallet 293 to one of the branches of the blocking circuit of the relay 290 and through the other branch goes through the armature pallet 283 from de-energized relay 280, armature paddle 245 to conductor C-278 to occupy the trunk line circuit.



   The earthing of the C stud to the researcher's benches also places a potential of occupying earth on the multiple of the C studs.



   The lamp 215 comes on when the searcher brushes engage on the pads 297 to indicate the interurban group on which the call is received.



   The long distance attendant receives the dial tone due to the operation of relay 1140 and the resulting operation of relays 1150 and 1160 and can converse with the remote operator over the TL-1 long distance line and be informed of the call. destination to be reserved for this call.



   Operation of the combiner control relays.



   The operation of relays 1610 and 1620 during the transmission of the digits stored during the last communication prepares the control equipment of the combiner so that when the operator in the position shown in fig. 11 receives another call, relay 1630 attracts by applying earth to conductor 1304 in order to connect the SL-2 transmitter circuit of FIG. 16 which is identical to the SL-1 transmitter circuit of fig. 15.



   When relay 1630 attracts it opens the circuit of

  <Desc / Clms Page number 72>

 blocking of relay 1610 by the normally closed contacts controlled by the armature pallet 1633 and consequently the relay releases and thereby establishes a blocking circuit for the right winding of relay 1620 to prevent the relay from releasing then that the SL-2 transmitter circuit is in service. Lamp 1600 will illuminate to indicate to the operator that the SL-2 transmitter circuit is ready for another operation i.e., the LF-2 finder circuit has been connected to the preselector finder such as the finder F-1 fig. 6 and that the SS-2 transmitter selector has been connected to a free transmitter recorder.



   The operator can then maneuver her DK sending keys according to the number requested, the equipment of the recording transmitter will record and retransmit the impulses in the manner previously described and during this transmission period the lamp 1600 will decrease in illumination and go off. will turn off when all stored digits have been retransmitted. The conductor 1304 will then be grounded causing relays 1630 and 1620 to release. Therefore the SL-1 transmitter circuit is again ready to connect a free transceiver through the transmit selector switch. - tor SS-1 to a pre-selector finder circuit via the LF-1 finder circuit.



   The attraction of relay 630 during the operation of finderscope F-1, fig. 6, when connecting the finder to the calling line, attracts relay 1340 which places a ground on conductor 1304. Assume that relay 1610 is ready to attract again when conductor 1504 is grounded in order to switch on the SL-1 transmitter circuit, fig. 15, for research

  <Desc / Clms Page number 73>

 a free recorder transmitter and to connect the SL-1 transmitter circuit and the selected recorder transmitter to the searcher-selector circuit.



   In the position of the operator's table the lamp 215 of the trunk line circuit, fig. 2, the lamp 603 of the researcher F-1, fig. 6, and the SL-1 transmitter circuit lamp 1500, fig. 15, are all on to give the operator the necessary signals to indicate that she can proceed with establishing interurban line calls.



   The long distance operator at the central office takes note of the call and receives the remote operator's indication of the destination to be reserved for this call.



   When the operator notices the illumination of the lamp 1500 indicated above, she operates her sending keys DK to register the number 284161 on the registers Rl-R6 inclusive of figs. 18 and 19. The recording and transmission of digits takes place as previously described.



   As soon as she has operated the disconnection key, the operator can reset her K-1 key and allow the equipment to be released from the position. When the key is K-1 reset, relays 670 and 660 / released because relay 670 circuit is open at contact 695 of key K-1 and relay 670 opens circuit for start relay 660 by the reinforcement pallet 677.



   Relay 670 disconnects the conversation conductors from the position conversation conductors circuit and connects them through the armature paddles of relay 680 and disconnects conductors 1355, 1356, 1302 and 608. Relay 670 turn off the lamp

  <Desc / Clms Page number 74>

 215 and disconnects conductors 606 and 607. Relays 620, 630 and 650 remain engaged. In the equipment of the position of pins 11 and 13, the relay 1130 releases when the conversation key K-1 is restored while the relay 1340 releases because the conductor 608 is disconnected as a result of the release of the relay 670. ' The position equipment is now in normal conditions ready for the attendant to accept a new call.



  Ground is removed from conductor 1304 when relays 1130 and 1340 release hence it follows that the initial circuit of relay 1610 is open and the shunt is removed from the coil of relay 1620. Relay 1620 then draws in. series with relay 1610 to prepare a new selection of the SL-2 transmitter circuit.



   The first TFS-1 long distance selector in fig. 7 responds to the first group of pulses which form the first digit 2 by raising the brushes to the height of the second level of its associated bank contacts and rotating the brushes in search of a free long distance office selector. Suppose that the TOS long distance office selector of FIG. 10 is the first which is found free, this selector is entered by means of the pads 1015 shown in FIG. 10.



   How the TOS long distance office selector works.



   When the TOS office long distance selector switch of Fig, 10 is grasped, ground applied to the incoming conductor C prepares relay 1010 to operate through the circuit loop comprising the positive and negative talk conductors and establishes the drive circuits for the top winding of relay 1030 and the bias winding of relay 1060. When the circuit loop comprising the positive and negative talk conductors

  <Desc / Clms Page number 75>

 is established by switching by means of the previous connector the relay 1010 attracts and by the armature paddle 1011 establishes an energizing circuit of the relay 1020. The energizing of the relay 1030 prepares the circuit of the electro- GREEN ascent magnet and a blocking circuit for its lower winding by the armature pallet 1033.

   Operation of relay 1020 establishes another point in the ascending electromagnet circuit through armature vane 1024.



  Since extension A's line number is 284161, the digit 2 is followed by subscriber number 84161.



   Relay 1010 is therefore actuated eight times in a row and each time a circuit is established from ground to armature vane 1046, armature vane 1011, and its normally closed contact, armature vane 1024, the armature pallet 1033, one branch of the circuit comprising the lower coil of the relay 1030 and the battery to keep the relay attracted during the upward movement of the switch and the other branch of the circuit comprising the coil of the electro- GREEN ascent magnet and battery. The GREEN ascension electromagnet acts whenever this circuit is established to raise brushes 1016 to the eighth level of the bank contacts.



  At the end of the pulses, relay 1010 remains attracted and the rear contact of the armature pallet 1011 opens the circuit of the lower winding of relay 1030 which releases and opens the operating circuit of the electromagnet. GREEN ascent through armature pallet 1033 and through armature pallet 1034 closes the following circuit for the rotation electromagnet ROT: to armature pallet 1046, armature pallet 1011, head contacts 1093, armature pallet 1034, ROT rotation solenoid self-interrupting contact, solenoid winding

  <Desc / Clms Page number 76>

 ROT rotation magnet towards the battery.

   Due to the action of the self-interrupting contacts on the ROT rotation electromagnet, brushes 1016 scan the bench contacts in search of a free junction circuit connected to a free junction line between offices going from the selector incoming long distance TMS units of thousand, fig. 2, at the automatic office requested N 8.



   Suppose that the TC-2 junction circuit of fig. 22 is grasped when the battery potential applied to pad C-2200 of the TOS banks via the winding of relay 2200 and the armature pallet. 2211 is extended by brush C of brush group 1016 for attract relay 1040. Relays 1040 and 2200 attract in series in a circuit going from the battery, by the winding of relay 2220, the armature pallet 2211, the stud C-2200, the brush C of the group of brushes 1016, the normally closed contacts controlled by the armature paddle 1031, the armature paddle 1021, the test winding of the relay 1040 and the incoming conductor C grounded.

   The pull of relay 2220, the winding of relay 2210 of the negative talk conductor by the armature vane 2212 and the relay 1040 in pulling establishes a blocking circuit for its guard winding through the vane. 1045 armature and incoming conductor C. Relay 1040 also applies an earth directly to brush C through armature paddle 1043 to keep the seized TC-2 junction circuit relay 2220 in its working position and to keep the line of contact. junction.

   The relay 1040 also stops the rotational movement of the switch by the armature vane 1046 and it prepares a guard and connection circuit by the forward contact of the same armature vane;

  <Desc / Clms Page number 77>

 by the armature paddles 1041 and 1042 it disconnects the incoming positive and negative conversation conductors of relay 1010 and extends them through the normally closed contacts of relays 1050 and 1080 and by the positive and negative brushes of the group of brushes 1016 to the conductor positive and negative conversion of the TC-2 junction circuit, fig. 2, and then via the T-5 junction line between offices to the TMS long distance selector for thousand units, fig. 1. The active coil of relay 1060 is connected in series with the positive talk conductor but it does not attract.

   Due to the pulling of the switching relay and the disconnection of the relay 1010 from the talk conductors, the relay 1010 releases and opens the circuit of the relay 1020 which also releases. Releasing the relays 1010 and 1020 prepares a circuit for the RLSE releasing solenoid with the circuit closed when the relay 1040 is returned to its normal position.



   As soon as the following digits are retransmitted the call is / is routed further by the operation of the TMS trunk selector of the thousand units, fig.l, the trunk selector of the hundreds and the local and trunk connector combined to the line of station A.



   After all the pulses have been sent to relay 1530 of fig. 15 attracts by a circuit established for its upper winding by the conductor 1507 and is blocked by a ground given by the armature pallets 1534 and 1562. By attracting the relay 1530 places a ground on the negative conversation conductor through the intermediary of the relay 1540 and the armature pallet 1531 and by the same action opens the circuit loop to the contacts normally closed by the armature pallet 1531; it connects the battery via the resistor R1 and the armature pallet 1532 to the conductor EC; by the reinforcement pallet 1533 it connects

  <Desc / Clms Page number 78>

 a ground to the conductor 1556 to attract the researcher relay 680, fig. 6; by the armature pallet 1535 the circuit of the lamp 1500 is opened.

   By armature pallet 1536 a protective earth is placed on the coil of relay 1510 to prevent releasing of the relay until relay 1530 releases. If the call has not been fully established by operation of the various switches in the switch train, battery potential will be applied to the negative talk conductor by one of the switch train switch line relays. When this occurs relay 1540 will attract and through armature paddle 1542 will prevent the application of a ground to conductor 1556 to attract finder relay 680 thus preventing the switch train from being connected to the circuit of the finder. associated researcher.

   When the operator returns the K-1 key, ground will be removed from conductor 1304 and the entire switch train at the same time as the SL-1 transmitter circuit will release. In the event that an incomplete call is encountered after the attendant returns her K-1 key to its normal position, the SL-1 transmitter circuit and the associated set of switches will release immediately after the 1540 relay has been pulled. .



   If the called party is not busy when the call is terminated on his line, relay 1540 of the SL-1 transmitter circuit will not pull and conductor 1556 is grounded through contacts of the armature pallet 1533 to attract the finder's relay 680, fig. 6, and the battery is connected to the EC conductor through the contacts of the armature pallet 1532 and the resistor R4 in order to introduce the translator coil and the capacitors of the TOS long distance office switches of fig. . 10 in the associated switch train circuit. Via the 1535 armature pallet, the 1530 relay opens the lamp circuit

  <Desc / Clms Page number 79>

 1500 which consequently goes out and by the same action opens the circuit of relay 1570.

   Relay 1570 therefore releases opening the circuit of relay 1560 through armature paddle 1572, but before relay 1560 releases a momentary negative pulse is applied to the positive talk lead 1553. via resistor R2 , the reinforcement pallet 1571, the reinforcement pallet 1561, the bar 1575 connected between terminals 1576 and 1577 to the positive conversation conductor of the junction in order to attract the call relay of the long distance office selector , fig. 10.



  It is understood that the bar 1575 connected between the terminals 1576 and 1577 of the transmitter circuit SL-1, fig, 15, is connected in the transmitter circuit provided inside the operator position only so that the call on distant lines can be triggered automatically. Relay 1560 slowly releases shortly after its circuit is opened by armature vane 1572 and by armature vane 1562 opens the blocking circuit of relay 1530 which also releases. When relay 1530 de-energizes the SL-1 transmitter circuit, fig. 15, is disconnected from the finder F-1, fig. 6, and communication is kept via relay 680 frame paddles.



   Let us now refer to the TOS trunk switch selector, fig. 10, it will be noticed that the momentary application of the battery potential to the EC conductor due to the operations indicated above of the relays of the transmitter circuit SL-1, fig, 15, establishes a circuit through the intermediary of the paddle. armature 1044, head contacts 1095, normally closed contacts controlled by armature paddle 1056, top winding of relay 1050, to earth.



  Relay 1050 attracts and blocks via incoming conductor C to rebar 1055; he introduces a trans-

  <Desc / Clms Page number 80>

 latrice 1000 by the armature pallets 1051, 1053 and 1054 and it opens its initial excitation circuit comprising its upper winding by the armature pallet 1056 and the normally closed contacts, and by the same action by the front contacts of the armature pallet 1056 prepares the supervision circuit for lamp 601 at the operator's table.



   When the connector such as C-1 enters the line of station A, the TMS trunk selector of the thousand units reverses the direction of the current in the trunk line T-5 to attract the relay 1060. By pulling the relay 1060 establishes a bypass on its line winding through the armature pallet 1061 in order to prevent the resistance of the relay from influencing the talk circuit; connects the incoming conductor C grounded to the armature pallet 1071 of relay 1070, to the armature pallet 1062 and through the armature pallet 1063 it establishes a multiple blocking circuit for the lower winding of the relay 1050 .

   The battery potential connected to the loop of the circuit by the TMS interurban selector of the mile units of the automatic office attracts the relay 1070 and by the armature paddle 1071 prolongs the earth which is applied to it through the intermediary of the armature pallet 1062 and from the incoming conductor C to the armature pallet 1056, the blanking contacts 1095, the armature pallet 1044 and to the incoming conductor EC thus completing the circuit via the preceding switches to illuminate the lamp 601 at the long distance operator position to indicate to the long distance operator that the call has been routed to the called subscriber line.

  <Desc / Clms Page number 81>

 



   Since the communication which has been described was established by an interurban operator has an interior position, the momentary application of the battery potential to the positive conversation conductor of the communication was automatically made by the action of the relays of the circuit of the communication. SL-1 transmitter, fig, 15, as previously described. In the TOS office long distance selector, fig, 10, the battery potential applied to the positive talk conductor passes through the armature paddles 1042 and 1054, the lower left winding of the transmission coil 1000, the armature pallet 1052, the winding of relay 1080 to earth.

   Relay 1080 is momentarily drawn and applies an inrush current through armature paddles 1081 and 1082 at the T-5 inter-office long distance service junction and causes the switches in the automatic office to perform the necessary operations. normal intermittent inrush current at the called line.



   The called subscriber answers.



   When the subscriber of station A answers the current in the T-5 trunk of inter-office inter-office service is discontinuous; and TOS long distance office selector relay 1070 drops, communication being held during conversation by the called line.



  When the relay 1070 releases it removes the earth potential of the conductor EC associated by the armature paddle 1071 thereby causing the extinction of the lamp 601 to indicate to the operator that the called party has answered.

  <Desc / Clms Page number 82>

 



   Note that the de-energization of relay 1080 establishes a blocking circuit for the selector by applying an earth potential through the armature paddle 1046 to the incoming conductor C through the armature paddles 1071 and 1062 d. 'where it follows that the selector does not return to its idle position in the event that the long distance operator cuts off the called side of the call while the receiver is off hook at the called station. It should also be noted that the relays 1040, 1050 and 1060 are blocked in their attractive position by means of the grounded conductor C.



   During conversation the relay 220 of the trunk line circuit, fig. 2, is kept attracted by the current supplied through the 44,000 ohm center tap resistors associated with the left winding of the translator coil 1000 of the TOS office toll selector. Therefore the relay 210 is prevented from operating so that the artificial line 214 is connected in this circuit.

  <Desc / Clms Page number 83>

 



   Supervisory signal ar return inrush emitted by the calling long distance office.



   If the calling long distance operator wishes to alert the long distance operator at the central office at any time after the communication has been established, she transmits a inrush current on IL-1 to momentarily attract relay 270. and to momentarily release the relay 260. The relay 260 closes the circuit of the upper coil of the relay 280 through the armature pallet 261 from which it follows that the relay 280 is momentarily attracted.

   With relays 280 and 290 attracted, a direct earth potential is placed on the conductor C going to the stud 297 of the researcher benches Fig. 6 thus causing the release of the relay 650, the cié K-1 being reestablished as it has been described. previously. not
Relay 280, however, does not lock / pull at this time and therefore releases and again removes the ground potential of conductor C going to stud 29 and finder relay 650. When earth is applied to conductor C and to stud 297 at the finder-finder banos in Fig. 6, it is extended further by means of brush C2 of brush group 618, the armature paddle 623 towards the lower winding of relay 650, earth being applied to the pad facing the lower winding of relay 650 by the armature pallet 634.

   Relay 650 returns to its normal position and places a short circuit on its lower winding through bar 653 and armature pallet 651.



  Relay 650 will not draw in series with relay 290 in the trunk line circuit as long as the short is maintained.



   The relay 290 however is kept attracted during this circuit modification first by the armor paddle 281 grounded and when this relay releases the earth is again given back by the armature paddle 634 by

  <Desc / Clms Page number 84>

 through brush C2 of brush group 618 and conductor C of pads 297. Lamp 602 is now permanently on to attract the attention of the long distance operator at the central office. this lamp goes out when the operator operates her K-1 switch to attract relays 670, 660 and 650.

   When relay 650 is re-drawn through its upper winding due to the pull of relay 660, the short of its lower winding is removed from the circuit and the relay will remain drawn in series with the relay. 290 of the trunk line circuit after the excitation circuit of its top winding has been removed. Researchers associated with the CLR operator position however are not expected with the bar 653 and the frame pallet 651 mentioned above since the CLR operators answer all CLR calls.



   Communication release,
When the called subscriber hangs up his receiver, the train of switches of the called office causes a reduction in the intensity of the current in the conductors of the T-5 junction between offices, drawing relay 1070 again by interconnecting conductor C again. earthed with the associated conductor EC from where it follows that the lamp 601 of the finder Fl Fig.6 lights up as an end signal.



     The long distance operator of the central office can release the calling side of the communication by operating her key K.8 and she can release the called party of the communication by operating her key K.12. The keys K.8 and K.12 allow the long distance operator to release. ' either one or the other side of the communication separately while the K.11 key is a combination of the K.8 and K.12 keys.

  <Desc / Clms Page number 85>

 



   Let us suppose that the long distance operator of the central office releases the communication by momentarily manipulating its olé K.11. It should be noted that contacts 1408 and 1409 of olé K.8 and that contacts 1414 and 1416 of key K.11 fulfill the same functions, i.e. place an earth on conductors 608 and 1443. In addition, contacts 1418 and 1419 of ole K.12 and contacts 1415 and 1417 of key K.11 also perform the same functions. The earthing of the conductors 1443 and 608 due to the momentary operation of the olé K.11 causes the release of the seeker F.1 Fig.6 in the same way as described above.

   When the finder F1 returns to its normal position, its brushes 618 are disconnected from the pads 297 to which the circuit of the trunk line TLC of Fig. 2 is connected from where it follows that the relay 290 releases in same time as relay 220. The circuit of the trunk line TLC is then available for a new use.



   The release of the called side of the call is the same as described above with regard to the release of the called side of the call by momentary operation of the K.12 key.



   In the selector of the long distance office TOS Fig.lO the relays 1040, 1050 and 1060 release as a result of the elimination of the earth potential of the incoming terminal 0-1015 by the previous selector. Releasing relays 1040 and 1050 breaks the blocking circuit through the positive and negative brushes of brush group 1016 to allow the called office switches to release.



   Congestion situation at the long distance office selector.



   If all the junctions accessible by the TOS long distance office selector on the chosen level are occupied, the brushes 1016 advance to the "full" position. When this position is reached, the contacts

  <Desc / Clms Page number 86>

 1095 disconnect the top winding of the 1050 relay to prevent unwanted pulling of this relay by the EC conductor after all ohifres have been retransmitted by the transmitter, while the 1094 obstruction contacts connect the winding top of relay 1030 in the circuit of the top winding or test of relay 1040 in order to attract the relay 1040 to stop the operation of the rotation eleotro ROT.

   This circuit runs from the battery to the top winding of relay 1030, blanking contacts 1094, test winding of relay 1040 to the incoming conductor C grounded. The relay 1030 is attracted to move the brush C of the group of brushes 1016 from the earth given by the armature pallet 1022 and therefore a momentary count pulse determined by the release time of the relay 1020 is sent by the brush C of brush group 1016. Relays 1030 and 1040 remain energized after relays 1010 and 1020 are released.



  A flashing supervisory signal is transmitted by the device driver at 60 pulses per minute through congestion contacts 1095, the EC lead to flash lamp 601 at the trunk table.



   The TOS trunk switch is released from the "congestion" position when ground potential is removed from the incoming conductor C to allow relays 1040 and 1030 to release.



   Calling busy lines,
When a called line is busy, the devices of the trunk of the long distance service cause in the trunk line T-5 between offices to reverse the direction of the current and its interruption at the rate of 120 times per minute which is twice that of the blinking. when all the junctions are occupied or the end situation

  <Desc / Clms Page number 87>

 bulk is met. In the selector of the TOS long distance office, the reversal of the direction of the current which occurs when the occupancy conditions are met causes the relay 1060 to be drawn.

   It follows that the intermittent attraction and release of relay 1070 caused by the intermittent current in the conductors of the T-5 trunk line between offices has the effect of placing an intermittent earth at the rate of 120 times per minute on the associated conductor entering EC through earth at armature paddle 1046 and switch armature paddle 1071 from relay 1070. This action results in a characteristic somewhat rapid flashing of lamp 601 to indicate to l operator that the called line is busy.



   When the long distance operator cuts off the communication under these conditions, the selectors release as described previously and the selector of the long distance office TOS releases between successive attractions of the supervision relay 1070. The switches of the called office release due to the opening. when the TOS selector is released.



   Call from the central office area to an office accessible by a TL2 long distance line.



   Let us suppose that the subscriber of station A of the automatic office N 8 calls the trunk table of the central office by the junction CLR and the junction line T-1 fig. 1 and 3 and requests that the line be connected to a line in the long distance office accessible by the TL2 trunk line. Suppose this call has been routed to a certain point and the F-1 seeker Fig. 6 has been connected to the T-1 junction through the CLR circuit of Fig. 3 and the long distance operator answered this call.



   In order to route the communication further, the operator operates the send key DK to send the number of the requested subscriber, preceding this number with digits.

  <Desc / Clms Page number 88>

 prefixes 4 and 6, characteristics of the TL2 trunk line.



   Fig, 1 indicates that the communication will be routed by the .CLR operator which is associated with the searcher F-2 and the first long distance selector TFS-1.



   Suppose that the lamp 1500 is lit to indicate to the operator that the transmitter recorder has been chosen and connected to the associated searcher-selector circuit of Figs. 6 and 7 respectively. The operator then operates her sending keys DK to record the prefix digits 4 and 6 followed by the number of the requested subscriber on the registers Rl to R6 inclusive of FIGS. 18 and 19 respectively. The operator then restores her K-1 key associated with the researcher F-1.



   The first interurban selector TFS-1 in Fig. 7 responds to the first train of pulses forming the first digit 4 and its brushes rise to the 4th level of the associated bank contacts and begin to rotate at When looking for a free trunk line selector, let's say the TLS-2 trunk selector in Fig.8.



   Earth is applied to conductor C through pad C-800 to prepare for the attraction of relay 810 through the circuit loop including the positive and negative talk conductors and to establish a drive circuit of. the upper winding of relay 830 through head contacts 881. The circuit loop is established by the switching operation of selector TFS-1 which has the effect of attracting relay 810 and setting an excitation circuit for relay 820.



   The pull of relay 830 connects brush C of brush group 801 to the bias winding of relay 870 through armature paddle 831, it prepares a circuit

  <Desc / Clms Page number 89>

 blocking for its lower winding by the green ascent magnet pallet of armature 832 in multiple with the circuit of the electro- / '. and it opens at one point the circuit of relay 860 by the rear contacts of the armature pallet 833 while by its front contacts it prepares a circuit for the relays 840 and 850.

   Due to the attraction of relay 820, earth at armature paddle 822 is applied to brush C of brush group 801 by armature paddle 831 and also to the bias winding of relay 870; earth at armature paddle 832 is connected to test winding of relay 870 to prepare test / brush circuit C through armature paddle 821 and normally closed contacts of armature paddle 831 after that relay 830 has released.



  By means of the armature pallet 824, the relay 820 prepares a circuit for the GREEN ascension solenoid and a blocking circuit for the relay 830.



   Relay 810 responds to the second digit and is momentarily released 6 times in a row each time establishing a circuit from the earth to the armature vane 876, the armature vane 811 and its rear contact, the tro-magnet vane. armature ascender 824 and its front contact, the winding of the elec- / GREEN towards the battery, one branch of this circuit being established for the lower winding of the relay 830 by the armature pallet 832 and the lower winding towards the battery.



  Both relays 830 and 820 are kept pulled during pulse trains. Closing head contacts 883 establishes a circuit for relay 840 through: earth to armature pallet 876, armature pallet 825, head contacts 883, armature pallet 833, relay 830, coil of relay 840 to battery. The relay 840 circuit is closed for the duration of the vertical movement in order to maintain a ground potential on the upper winding of the relay 850 to prevent the relay 850 from attracting prematurely.

  <Desc / Clms Page number 90>

 when the VW tese vertical brush passes over the grounded vertical test contacts.



   Automatic level selection.



     At the end of the pulse trains, the brushes 801 are located opposite the sixth level of the bank contacts. Relay 830 releases shortly after the last level choice pulse is received by the ascending solenoid and the armature paddle 832 prepares an automatic level selection circuit for the ascending solenoid GREEN, at the same time opening the initial circuit of relay 840 through armature paddle 833. Releasing of relay 840 depends on whether all the junctions of the sixth level of bank contacts are in service or not.

   If all of these junctions are in use, relay 802 is pulled in and has removed the earth potential of the sixth level test contacts in the banks of all vertical test brushes such as VW switches having access to automatic trunk lines. , when this happens there is no guard circuit for relay 840 nor an operating circuit for relay 850 by the VW vertical test brush and relay 840 releases to give an additional impulse to the electro- GREEN lift magnet from which it follows that the switch takes one more vertical step to go to the next level on which the same occupancy test is carried out.

   This self-interrupting circuit of the ascension electromagnet is established by a ground at the armature vane 876, the armature vane 825, 820, the head contacts 883, the armature vane 833, the reinforcement pallet 83, reinforcement pallet 841, reinforcement pallet 832, the winding of the GREEN ascent electromagnet towards the battery. The ascension electromagnet will attract by this circuit and make the brushes rise by one step and by its armature paddle 891 it establishes a circuit to make the relay 84U attract again, in order to stop the movement. - vertically by opening the electromagnet circuit

  <Desc / Clms Page number 91>

 Ascension tro-magnet by the armature pallet 841. Lëlec- releases and opens the circuit of the relay 840 by the armature pallet 891.

   This removes the earth potential of the top winding of relay 850 so that the vertical broom VW can test the 7th switch level by the earth potential.



  If free trunk lines are now available in the 7th level, the earth potential is returned by the VW vertical test brush through the upper winding of relay 850 and the winding of relay 840 to the battery. '840 remains attracted to prevent continued vertical brush movement and relay 850 attracts. Through the armature pallet 852, the 850 tro-magnet ascension relay prepares the circuit of the electec- and through the armature pallet 851, it establishes a blocking circuit for its lower winding by ground to the pallet frame 876.



   Now suppose that there are one or more free junctions on the level where the junction called (the sixth) the relay 802 is located, does not attract when the selector brushes return to rest. Under these conditions, releasing relay 830 at the end of the pulse trains allows relay 850 to draw in series with relay 840 by a circuit comprising the vertical test brush VW, the 6th level of the test contacts. vertical and the contacts of relay 802 de-energized to earth.



  Relay 850 closes the blocking circuit for its bottom winding through armature paddles 851, 833, head contacts 883, armature paddle 825, armature paddle 876 to earth. Relay 850 also opens another point of the stepping GREEN self-magnet ascent progression circuit of the electro- / at the rear contact of the armature vane 855 and through the front contacts of the armature vane 852 it closes the auto-switch circuit

  <Desc / Clms Page number 92>

 of the rotational electromagnet ROT. Brushes 801 thereby step by step scan the sixth level of the bank contacts looking for a free junction.



   From the first step of rotation, the VW vertical test brush is released from the vertical test bench thus opening the indicated circuit which would precede respectively for relays 840 and 850. Relay 840 releases but relay 850 is kept drawn into the circuit. blocking indicated above to keep closed the self-interrupting circuit of the rotation electromagnet and open the circuit of the tro-magnet ascension electromagnet. The ROT rotating electromagnet rotates the brushes 801 stepwise on the bank contacts of the chosen level until a free trunk line is reached.



   Relay 860 was attracted due to releasing of relay 830 at the end of the level pick pulses.



  By attracting, relay 860 places a battery potential on the incoming conductor Ec through resistor R-8 and armature paddle 861. This battery potential applied to the incoming conductor EC causes relay 1550 to attract. circuit of transmitter SL-1, fig. 15, The attraction of relay 860 is carried out in order to prevent the transmission of additional pulses by the equipment of the recorder transmitter during the time that the Trunk line selector TLS-2, fig. 8, is looking for a free trunk line in the selected group of trunk lines, If the transceiver transmitter equipment continues to / transmit pulses to the normal transmission speed,

   the additional pulses may be received by the TLS-2 trunk selector before the brushes 801 have selected a free trunk line from the desired trunk group. Therefore any pulse retransmitted by the transmitter

  <Desc / Clms Page number 93>

 recorder before a trunk line has been selected will be lost and a call will result with a wrong number.



   If the TL-2 trunk line associated with the IR-2 repeater Fig.l is the first that is found free, a battery potential will be encountered by the brush C which will thereby establish an excitation circuit for it. - relay test bearing 870. This circuit can be considered as starting from the battery encountered by the brush
C of brush group 801, normally closed oontaots controlled by armature paddle 831, armature paddle 821, relay test winding 870, to incoming grounded C conductor. Relay 870 draws (through this circuit and is blocked by its middle blocking winding from the incoming C conductor grounded through armature paddle 875.

   The ascension tro-magnet relay 870 also opens the self-interrupting circuit of the electro- the blocking circuit of relays 850 and 860 by the armature paddle 876, it establishes a bypass on its own coil. - test element by placing an earth on the brush C of the group of brushes 801 by the reinforcement pallet 873; it extends the incoming EC conductor to the TR-2 repeater of the
Fig.l through the armature pallet 874 and it disconnects the incoming positive and negative conversation conductors from the windings of relay 810 and extends them to the repeater IR-2 through the front contacts of the armature pallets 871 and 872 and the positive and negative brushes of the brush group 801 respectively. Relay 810 releases and relay 820 releases with a delay.

   De-operation of relay 860 removes the battery potential of the incoming EC conductor to allow relay 1550 of the SL-1 transmitter circuit Fig. 15 to release. When relay 1550 releases the logger transmitter equipment operates

  <Desc / Clms Page number 94>

 again to transmit the remaining pulses forming the digits recorded on the associated recorders.



   Referring to the transmitter circuit SL-1 Fig. 15, it will be noted that when relay 1550 attracts, it disconnects relay 1520 from the series circuit comprising the relay, 2040 Fig. 20 and connects it to a blocking earth potential through the front contact controlled by the armature pallet 1551. The relay 1520 remains attracted by this circuit to keep the loop of the circuit comprising the relay 810 closed. The relay 2040 however releases and by armature pallet 2041 passes the earth potential of conductor 1754 to conductor 1755, thereby bypassing the lower bearing of relay 2080. As long as relay 2080 is prevented from attracting, no new digit is not transmitted.

   Removing the battery from the EC conductor when releasing relay 860 allows relay 1550 to release and reconnect the pulse circuit including relays 1520 and 2040. Relay 2040 removes the shunt from the relay winding 2080.



  Relay 2080 can then attract in the manner previously described, thereby allowing the transmitter equipment to transmit the next digit.



   The remaining pulses transmitted by the fact of pulling relay 1520 of the transmitter circuit SL-1 Fig. 15 are received by the pulse repeater IR-2 Fig.l and are retransmitted on the trunk line TL-2 to make progress by steps the automatic switches of the remote office towards the line of the called subscriber. If the called subscriber's line is not busy when the call is established, the office switches

  <Desc / Clms Page number 95>

 remote function and cause the IR-2 pulse repeater in Fig. 1 to apply a ground potential to the EO brush group 801 in the TLS-2 inter-city line selector in Fig. 8.

   This ground potential is fed back through the TLS-2 trunk selector selector and through the first / trunk in the TFS-1 working position to illuminate the 601 lamp at the central office trunk operator position. to indicate that the call has been routed to the called line and that this line is free and has been seized.



   The operator observing that the lamp 601 is on now and momentarily operates her key K-13 so that the battery potential will be applied to the positive conversation conductor to activate the automatic call from the telephone line. subscriber requested by the calling equipment of the remote long distance office. The detailed operation of the equipment at the central office trunk table due to the momentary operation of the K-13 call key is the same as described above.



   Response supervision signal.



   When the called subscriber answers, the usual supervisory maneuver takes place in the train, from the switches of the called office, to cause the return transmission of a response supervision signal on the TL-2 trunk line to the IR-2 pulse repeater of Fig.l.



   In the calling central office network when this response supervision signal is received by the IR-2 pulse repeater, the earth is disconnected from the EC brush of brush group 801, which turns off the lamp 601 at the central office long-distance table (researcher

  <Desc / Clms Page number 96>

 F-1 Fig. 6) to inform the long distance operator that the call has been answered.



   The conversation then takes place via the established communication. The long distance operator at the central office marks the long distance card to indicate the start time of the communication and she also restores her K-1 conversation key to disconnect the calls. conversation conductors of its communication position so that it can establish further communications.



   End of communication supervision signal.



   When the conversation is over and the called subscriber of the remote long distance office hangs up his receiver, the pulse repeater 1R-2 is again controlled by the switches of the remote office to place a ground on the broom EC of the 801 broom group. of Fig. 8. When this happens, lamp 601 is turned on again to give the supervisory signal to the long distance operator of the central office long distance table.



   It is understood that if the called subscriber of the remote long distance office wishes to inform the operator of the long distance table of the central office, he can do so by operating the contact of his switching fork a number of times so that the lamp 601 starts blinking.



   When the calling subscriber from the automatic office N 8 hangs up his receiver, the relay 650 will release and cause the lighting of the lamp 602, indicating to the long distance operator the end of conversation signal of the calling subscriber.

  <Desc / Clms Page number 97>

 



   Release of communication.



   The attendant can now release the call by operating the K-11 key, thereby freeing the calling side and the called side of the call. Releasing the first TFS-1 long distance selector in Fig. 7 and the searcher F-1 of Fig. 6 have been previously described.



   In the TLS-2 trunk selector Fig. 8 when the earth is removed from the 0-800 pad when releasing the first TFS-1 trunk selector, the relay 870 releases and disconnects the brushes 801 at the same time as it closes a circuit through the armature paddle 876 through the contacts of the relays 810 and 820 at rest and through the head contacts 882 for the RLSE release electronics. By the attraction of the RLSE release electro, the 801 brushes return to their normal position.



   Congestion situation at the TLS-2 trunk selector.



   The operations that take place when a congestion situation is encountered at the TLS-2 interurban line selector will be explained.



   The automatic level selection of this selector is under the control of relay 850 and the VW vertical test brush and if no free junction is found in the last level of the group the selector brushes continue to rotate until so that they pass on the eleventh position of rotation or "encumbrance" position. When this position is reached, the blanking contacts
884 are closed to provide a new operating circuit from the battery through the upper winding

  <Desc / Clms Page number 98>

 of relay 830, clearance contacts 884, test winding of relay 870, incoming conductor C grounded. Relays 830 and 870 will both pull through this circuit, relay 870 opening the ROT rotation magnet circuit in stepping of the electro- / armature pallet 876.

   The relays 810 and 820 return to their normal position and the relay 870 is then kept attracted by a blocking circuit comprising its middle winding, the armature pallet 875 and the incoming conductor C grounded. Relay 830 remains attracted to incoming conductor C grounded in series with the top winding of relay 870 through actuated clearance contacts 884.



   During the time required for relay 820 to release, a count pulse is transmitted through the earth given by the armature pallet 822, the armature pallet 831, the relay 830 attracted and the brush C of the group of brushes 801.



   The supervisory pulses of approximately 60 pulses per minute are transmitted back by the incoming conductor EC through the congestion contacts 885 to flash the lamp 801 and thereby alert the calling trunk operator of the occupation. - tion of the group.



   When the previous switch returns to key idle due to the / K-12 maneuvering by the interurban operator at the central office, the earth potential is removed from the incoming conductor C of the TLS interurban line selector. -2 thereby eliminating the blocking circuit of relays 830 and 870 which then return to their normal position. Through armature paddle 876, relay 870 establishes a circuit through armature paddles 811 and 824

  <Desc / Clms Page number 99>

 and the head contacts 882 of the RLSE release solenoid which pulling it releases the selector in the usual manner.



   Busy line called.



   When the called long distance line is busy, the long distance operator position lamp 601 will flash at the rate of 120 times per minute instead of 60 times per minute. When the long distance operator receives the flashing signal characteristic of a busy line, she operates her K-12 key to release the called side of the communication but she does not operate the K-8 key in order to keep the side. caller of communication. The attendant can then re-establish the connection to call the requested subscriber.



   Calling an interurban operator via the TL-2 interurban line.



   In order to ensure the routing of the communication described above to the trunk table located at the far end of the TL-2 trunk line instead of to the called subscriber, the trunk operator of the office central transmits the digits 4 and 6 by its call keypad DK to route the communication to a group of trunk lines to which the trunk line TL-2 belongs. The transmission of inrush current after seizure of the TL-2 trunk line without the intervention of other digits has the effect of warning the operator at the end of the TL-2 trunk line.



   In the communication described, the transmission of digits 4 and 6 to choose the trunk group in which the TL-2 line is located is immediately followed by the call control pulse which has the effect of notifying the user. long distance operator at the remote long distance office.

  <Desc / Clms Page number 100>

 



   Suppose the communication is routed through the seeker-selector circuit of Figs. 6 and 7 and the TLS-2 trunk selector to the TL-2 trunk line via the IR-2 repeater of Fig.l. This repeater works to connect relay 1540 of the SL-1 transmitter circuit of Fig. 15 to the negative conversation lead at the same time as it opens the positive conversation lead to make the junction unpowered.



  When relay 1540 releases due to de-energizing the loop circuit, relays 1560 and 1570 momentarily connect the negative pulse controlling the call to the positive talk lead of the junction to control the call relay in the repeater. IR-2. At the central office, lamp 601 turns on and the IR-2 repeater controls signaling to the trunk operator at the far end of the TL-2 trunk line.



   The central office attendant position lamp 601 remains on for the time that elapses until the remote office long distance operator is notified and when the remote office attendant answers, the response supervision is transmitted back to the TL-2 trunk line to cause lamp 601 to turn off in order to give the trunk attendant at the central office a response supervision signal by turning off the telephone. lamp.



   The long distance operator at the central office gives the remote long distance operator the information necessary for routing the call to the called subscriber in the far long distance office area.



   After the established call is terminated and the long distance operator at the central office receives

  <Desc / Clms Page number 101>

 the end of communication supervision signal by turning on its call supervision and response lamps 601 and 602 respectively, it can operate its key K-11 to release the entire communication.



   Call from the long distance office to the local manual office N 4.



   Suppose now that a subscriber of the inter-city office (interconnected by means of trunk lines such as trunk line TL-1) calls the subscriber of station B and the call is received by trunk line.
TL-1 which terminates at the TLO trunk circuit of the
Fig. 2.



   When the TL-1 trunk line is seized at the remote office and inrush current is sent to that line, relay 270 is actuated to open the relay 260 field circuit. Relay 280 is by default. sequent attracted causing the conductor to ground
286 to put. turn on the distributor of Fig. 12 and to mark the conductor C on the researchers' benches.



   It will be assumed that an interior operator at the central office table Fig. 11 has manipulated her conversation key K-1 to choose a free researcher, such as researcher F-1 in Fig. 5 and therefore has marked its position as "free" on the distributor test circuit
Fig. 12. In addition, it will be assumed that the researcher was chosen by the operation of the distributor to respond to this call. Finder F-1 in Fig. 6 searches for the circuit of the calling trunk line and when found, the trunk operator at the central office receives the dial tone indicating it is seized. The long distance operator converses with the remote operator by

  <Desc / Clms Page number 102>

 TL-1 trunk line and receives information as to the destination of the call to be routed.



   Interurban line circuit 215 lamp
TLC is on to indicate the trunk group through which the call is received, lamp 603 is on to indicate the link circuit used for connection with the calling line, and lamp 1500 is on to indicate that the SL- transmitter circuit 1 has found a free recorder transmitter equipment and is ready to receive the digits of the requested number.



   Having read the call and having received the number of the called subscriber who in this case is subscriber B of the local manual office belonging to the central office zone, the operator is then ready to send the call. 'call by the maneuver of himself; sending keys DK.



   The operator of the internal position of the table when she wants to send the digits of the number of the called subscriber must precede them by the prefix continued by the digits 2 and 4 for selecting the junctions.



   Operation of the first long distance selector.



   When the long distance operator notices that the 1500 lamp is on, she operates her sending keys
DK to store the digits 2 and 4 in addition to the subscriber number of set B. The digit registration and retransmission takes place as before and the first TFS-1 long distance selector in Fig. 7 answers to the first group of pulses forming the first digit 2 by raising its brushes to the height of the second level of its associated bank contacts and rotating them automatically in search of a free long distance office selector. The selector of the TOS long distance office

  <Desc / Clms Page number 103>

 of Fig. 10 is the first which is found free and is therefore seized by the studs 1015 shown in FIG.



   Operation of the TOS interurban office selector.



   When the TOS trunk switch of Fig. 10 is entered, ground potential is applied to conductor 0 preparing relay 1010 to operate on the circuit loop comprising the positive and negative reverse conductors. The interurban desktop selector responds to the second group of pulses forming the second digit 4 by raising its brooms to the 4th level of its associated bench contacts.



   Bases 1016 then scan the bank contacts for a free junction circuit analogous to the TC-1 junction circuit shown in FIG. 22A, connected to a trunk line between offices which is free such as trunk line T-3 going to repeater R-1 of
Fig. 23 and 24 of the manual office called No. 4.



   Suppose the first free junction circuit reached by brushes 1016 is the TO-1 junction circuit of Fig. 23. When this occurs, the battery potential applied to the 0-2250 pad of the TOS selector bank through the winding of relay 2270 and the armature pallet 2261 is met by brush C of the switch group. brushes 1016, The relays 1040 and 2270 draw in series in the circuit going from the battery by the winding of the relay 2270, the armature pallet 2261, the stud
0-2250, brush 0 of brush group 1016, normally closed contacts controlled by armature vane 1031, armature vane 1021 and test winding from relay 1040 to incoming conductor C set to Earth.



   The attraction of relay 2270 of the TC-1 junction circuit

  <Desc / Clms Page number 104>

 removes battery potential through the winding of relay 2260 from the negative talk lead through armature paddle 2271. TOS selector relay 1040 attracts to extend the loop of the pulse-giving circuit to junction circuit TC-1 and the junction line T-3 to the repeater R-1 of manual office n 4. Relay 1040 also places a direct earth potential on brush C to keep the junction circuit and it stops the rotational movement of the switch and prepares the supervision circuit by the EC conductor, as indicated previously.



   Entering the repeater R-l.



   When the loop of the circuit shown above is extended by the positive and negative talk conductors to function T-3, a circuit is established for the relay 2410 of the repeater R-1 shown in Figs.



  23 and 24. The operating circuit of relay 2410 passes through: earth, upper winding of relay 2410, normally closed contacts controlled by the armature pallet 2354 the armature pallet 2342, the upper winding of relay 2330, the armature paddle 2352, the armature paddle 2311, the positive conversation conductor of the circuit loop including the pulse contacts 1521, return through the negative conversation conductor, the armature palettes 2312 , 2351 and 2341, the lower winding of relay 2330, the normally closed contacts controlled by the armature pallet 2355, the lower winding of relay 2410 to the battery. Relay 2410 draws through this circuit and establishes an operating circuit from relay 2420 through ground to armature vane 2411.



   It will be assumed that the recorder selector

  <Desc / Clms Page number 105>

 (not shown) associated with the repeater R-1 has its brushes connected to a busy recorder (not shown). Therefore when the repeater R-1 is seized and the relays 2410 and 2420 are pulled, the conductor 2373 is grounded and establishes a circuit for the operation of the electro of the associated logger selector, by the following circuit : conductor 2373, reinforcement pallets 2359,
2444 and 2424, conductor 2375 to attract the electro of the recorder selector to cause the advance of his brushes in search of a free recorder. R-1 repeater relay 2440 is shorted to ground to frame paddle 2421 so that it cannot attract until a free recorder is found.



  Through armature paddle 2422, relay 2420 prepares a circuit for the transmission of pulses through conductor 2374 and through armature paddle 2423 opens the circuit of relay 2310 to prevent the junction busy relay attract and disconnect the talk leads from the T-3 junction of the R-1 repeater. When a free logger (not shown) is found by the logger selector (not shown), ground is removed from conductor 2373, thereby removing the short circuit of the coil of relay 2440. When this occurs, relay 2440 attracts through a circuit from earth to the armature pallet 2412, the armature pallet
2357, winding of relay 2440, conductor 2375 to battxie via the electro of the recorder selector.

   The electro of the recorder selector (not shown) does not attract in series with the resistance of relay 2440 but relay 2440 attracts and replaces an indirect earth by the armature paddle 2421 held on the conductor 2373 by a direct earth from rebar 2444. The direct earth placed on the con-

  <Desc / Clms Page number 106>

 Driver 2373 locks the gripped recorder (not shown) while closing the contacts on the armor paddle 2441 prepares the pulse circuit to the gripped recorder via conductor 2374.



   Repeater R-1 is now prepared to receive the pulses forming the remaining digits of the requested subscriber number. Relay 1520 of the transmitter circuit SL-1 Fig.15 interrupts the circuit of relay 2410 by pulse contacts 1521. Relay 2410 follows the pulses of each received train causing the operation of the various recorders of the control equipment. signaling of calls, in order to display the number of the subscriber requested on the lamp panel at the position of the operator's table B. The impulses to operate the various recorders are transmitted from the earth to the armature pallet 2410.

   Whenever relay 2410 releases, this ground is applied through armature paddles 2422, 24-il, and 2423 on conductor 2474 to operate the loggers listed above. Relay 2420 is of the slow release type and remains engaged during the momentary interruption of its circuit by releasing relay 2410.



   When the lamps in the call indicator panel of the taole are on, a ground is applied to conductor 2376 to attract relay 2470 and cause lamp 2415 to be illuminated by the following circuit: lamp conductor grounded ,, paddle armature 2442, relay coil 2470, armature pallet 2356, armature pallet 2492, lamp 2415 to battery. One branch of the circuit includes armature paddles 2472 and 2406, lamp 2416, and battery. The two lamps 2415 and 2416 will illuminate the last lamp only lighting up momentarily.

  <Desc / Clms Page number 107>

 t momentarily because of the immediate attraction of relay 2470 in series with lamp 2415.



   The way in which operator B handles the call signaled in front of her by the call indicator lamp panel will now be considered. The 2415 lamp which is particular to the end of the repeater R-1 where one plugs in, lights up simultaneously with the lamps in the lamp panel thus allowing the operator to know which of the repeater circuits is being used by the incoming call. When the operator has read the line number of the called subscriber and knows from the winding of the call lamp 2415 that the repeater R-1 is the one being used, the The operator will test the jack in multiples on the line of the requested subscriber with the head of its plug P in the usual way in order to find out whether the called line is busy or not.



   Due to the momentary application of the battery to the positive talking lead, the TOS long distance office selector relay 1080 of Fig. 10 is momentarily attracted and connects the call generator GEN to the negative talking lead and the earth to the positive conversation conductor of the T-3 junction via the positive and negative brushes of the brush group 1016. When this occurs the relay 2320 of the repeater R-1 Fig. 23 is momentarily attracted and Closes a circuit from relay 2450 through armature pallet 2321.



  Relay 2450 pulls and locks through armature paddle 2453 through armature paddles 2461 and 2482 to ground at armature paddle 2421. When the negative impulse on the positive conversation conductor is removed from the de-energizes relay 1560 of the

  <Desc / Clms Page number 108>

 SL-1 transmitter circuit in Fig. 15, TOS toll office selector relay 1080 releases and reconnects the talk leads of the circuit through repeater R-1. Relay 2320 releases and opens the initial drive circuit of relay 2450 which is now blocked through the circuit including armature vane 2453.

   When operating relay 2450, a circuit is prepared for relay 2450 by armature pallet 2451 and the inrush circuit is prepared by closing the front contacts of armature pallet 2452.



   The repeater R-1 is then prepared for the called subscriber's call, which will be made when the operator inserts the P plug into the called subscriber's line jack.



   Called line busy.



   If the line requested is busy, operator B operates the occupancy key, thus applying an earth potential to conductor 2379. Relay 2480 is then attracted by armature pallets 2471 and 2402. Relay 2480 is activated. blocks by the reinforcement pallet 2482 and a ground to the reinforcement pallet 2421.

   Via the rear contacts of the armature pallet 2482, the relay 2480 opens the blocking circuit of the relay 2450 which releases; it establishes a circuit for relay 2350 from grounded conductor 2376, armature paddles 2442 and 2484, normally closed contacts controlled by armature paddle 2357, winding of relay 2350 to the drums; and through the armature pallet 2481, it connects the conductor 2377 to the upper winding of the relay 2340 by the following circuit: conductor 2377, armature pallet

  <Desc / Clms Page number 109>

 2481, resistor R9, lower right winding of translator coil 2360, upper winding of relay 2340 to the battery.



   Due to the attraction of relay 2350, the current which circulates in the conversation conductors of the junction is reversed by the reinforcing pallets 2354 and 2355; thereby reversing the current in the upper winding of relay 1060 of the selector of the TOS interurban office in Fig. 10 to prepare the supervision circuit by the lamp 601 of the interurban operator's table . Relay 1070 is also drawn to the circuit loop and makes a circuit through armature paddle 1071 to ignite lamp 601.

   The R-1 repeater relay 2340 attracts and releases quickly and therefore removes the talk lead battery from the T-3 junction at the contacts, rear of the armature paddles 2341 and 2342; to the front contacts of the armature pallet 2342, the relay 2340 establishes a blocking circuit for the lower winding of the relay 2410 from earth to the armature pallet 2431 to prevent the relay 2410 from releasing at the time where the 2340 relay is drawn.

   This rapid removal of the battery potential of the conversation conductors at junction T-3 acts as a switch circuit for relay 1070 of the toll office selector Fig.10. Conductor 2377 intermittently connects a ground to the conductor at a rate of about 120 per minute and therefore relay 2340 also pulls in and releases at the same rate at the same time as relay 1070. When this happens, the intercity operator table lamp 601 circuit is interrupted at the same rate, hence. the result is a characteristic flashing of the lamp 601.

  <Desc / Clms Page number 110>

 



   As a further result of the pull of relay 2350, a direct earth applied to conductor 2373 is removed by reinforcing pallet 2359 and has the effect of returning the call indicator equipment to its normal position (not shown). ; it is blocked by the ground with the armature pallet 2421 and it opens the circuit of the lamp 2415 by the armature pallet 2356.



   The long distance operator of the central office releases the called side of the communication by operating the key K-12 which has the effect of releasing the selectors used for the present communication and as described previously the selector of the TOS long distance office of Fig.10 releases between successive attractions of relay 1070. When the selector of the TOS trunk office releases, it opens the loop circuit of relay 2410 when relay 340 has returned to its normal position; this relay releases and opens the circuit of relay 2420. Through the armature paddle 2421, the relay 2420 removes the ground of the relays 2350 and 2480 and consequently the repeater R1 is returned to its normal position.



   Line called free.



   If the called line is free, the attendant will insert the P plug into the line jack of the requested line (not shown) and cause the immediate pulling of the 2400 relay through the conductor ending in the barrel of the jack set. to the earth and belonging to the line of the called subscriber. The called line cut-off relay is energized in series with relay 2400 to disconnect the line from its normal connections with battery and earth.



   When the 2415 lamp is on, the 2410 relays

  <Desc / Clms Page number 111>

 2420,2440, 2450,2470 are all attracted when the operator inserts the card.? into the jack of the requested subscriber line. Therefore when the relay 2400 is attracted, it performs the following various operations: by the armature pallet 2401, the relay 2400 removes the conductor 2378 from the head of the plug P and by its front contact prepares a point of the conversation circuit ;

   by armature pallet 2402, it opens a point of the circuit of relay 2480, it opens a point of the blocking circuit of relay 2490 by armature pallet 2403, by armature pallet 2407 it establishes a circuit excitation for relay 2350 by conductor 2376, armature paddles 2443 and 2407 normally closed contacts controlled by armature paddle 2357, winding of relay 2350 to the battery; and by paddle d armature 2408, it prepares a circuit for the lamp 2416 which is at this moment open thanks to the relay 2350.



   Relay 2450, on pulling, blocks through armature vane 2357 and its forward contact by a ground to armature vane 2421 while at rear contacts of the same armature vane the initial excitation circuit relay 2440 is open allowing the relay to release while through the normally closed contacts controlled by the front contacts of the armature pallet 2357, it opens its initial excitation circuit in order to release the relay 2440 and the subsequent disconnection driver 2376 will have no effect on relay 2350 at this time.



  As a further result of the pull of relay 2350, the inrush current is then sent to the line called by the following circuit: conductor 2371, armature pallets 2353 and 2452, neck of the P plug, inrush conductor the

  <Desc / Clms Page number 112>

 line of the called subscriber and through the ringing associated with it return by the line conductor to the head of the plug P, the reinforcement pallet 2401, the armature pallet 2451 of the call relay 2450 attracted, winding of relay 2460 to the battery.

   At the same time, a call return circuit is established for the transmission of the call tone to the calling subscriber (or to the outside operator if she has not returned her conversation key K -1) through tone capacitor 2409, armature paddle 2481, resistor R9, lower right winding of translator coil 2360, upper winding of relay 2340 to the battery. The tone current flowing through the right winding of the translator coil 2360 induces a tone in the left winding which can be heard by the calling subscriber or the long distance operator as appropriate.

   The attraction of relay 2350 removes the shunt from the left winding of the translator coil 2360 by opening the contacts of the armature paddles 2351 and 2352 so that the tone indicated above can be heard by the one who is listening. As a further result of its attraction, relay 2350 at one point opens the circuit of lamp 2416 through armature paddle 2358; it removes the earth of the conductor 2373 through the reinforcement pallet 2359 thus allowing the associated call indicator to return to its normal position;

   it opens the circuit of relay 2470 to the rear contacts of the armature pallet 2356, while by its front contacts it prepares a circuit to connect the lamp 2415 to the conductor 2377 in order to make operator B appear to flash the lamp in the event that it prematurely removes the P plug from the jack of the called subscriber line. In addition, by the reinforcing pallets

  <Desc / Clms Page number 113>

 2354 and 2355 the 2350 relay reverses the direction of the current in the conversation conductors of the T-3 junction thereby causing the pulling of the switching control relay 1060 of the TOS office long distance selector Fig. 10. R-1 repeater relay 2330 will not pull because its windings are in opposition.



   Supervision signal for the interurban operator of the central office.



   Referring now to the selector of the TOS long distance office Fig. 10 it will be noted that when the direction of the current in the T-3 junction is reversed, the current through the upper winding of the relay 1060 is in the correct direction and the relay attracts and bypasses its top winding by armature vane 1061. However the relay will not release because of its guard circuit maintained across its bottom winding. Through armature pallet 1062, relay 1060 connects the incoming 0 conductor grounded through the armature pallet 1071 and through armature pallet 1063 connects the incoming C grounded conductor through the lower winding of relay 1050.



   When all the digits have been retransmitted by the recording transmitter equipment of the long-distance operating table, a momentary pulse from the battery is applied to the EC conductor having the effect of attracting the 1050 relay through its upper winding. - laughing.



   If the relay is not attracted for some reason the circuit established for its bottom winding by the armature vane 1063 of the relay 1060 will cause the relay to pull at this time. Suppose however

  <Desc / Clms Page number 114>

 that the relay was previously pulled, and that relay 1070 is pulled through the circuit loop in series with relay 2410 of repeater R-1. Therefore when the earth is connected to the armature pallet 1070, it is extended by its front contacts, the armature pallet 1056, the clearance contacts 1095, the armature pallet 1044, to the conductor. EC, thereby causing the lamp 601 to be turned on at the position of the interurban operating table.

   If the long distance operator has brought back her K-1 key, she will not hear the call tone signal in return but will know that the called subscriber is currently called because of the illumination of lamp 601. D on the other hand, if she has not returned her K-1 key, she will hear the ringing tone signal back, she will also receive the visual signal and return her key.



   The called subscriber answers.



   When the called subscriber answers, relay 2460 of repeater R-1 pulls and opens the blocking circuit of relay 2450 by armature paddle 2461. Relay 2450 releases, opening the excitation circuit of relay 2460 by the front contacts of the armature pallet 2451 and removing the conductor 2371 from the called subscriber line to the front contacts of the armature pallet 2452 while at the rear contacts of these armatures it connects the called subscriber line to the right hand windings of the translator coil 2360 thus establishing a conversation circuit for the called subscriber. Relay 2340 attracts via the loop of the called subscriber and de-energizes junction T-3 via reinforcement pallets 2341 and 2342.

   Through the rear contact of the armature pallet 2341, the relay 2340 opens the circuit for the upper winding of the

  <Desc / Clms Page number 115>

 relay 2410 which cannot release because of the closed circuit through its lower winding via the front contact of the armature pallet 2342; through the front contact of the armature pallet 2341 the left windings of the translating coil 2360 are connected in series with the conductors of junction T-3, while through the rear contact of the armature pallet 2342, the battery from the lower coil of relay 2410 is disconnected from the upper coil of relay 2330 and from the lower left coil of the transfer coil 2360.



   When the T-3 junction is unpowered, the TOS supervisory relay 1070 returns to its normal position thereby removing the earth potential of the incoming conductor EC coming from the trunk attendant table. earth potential is removed from the conductor EC the lamp 601 of the long distance operator position is off. The required conditions being established, the subscribers can then converse.



   Supervision signal by action of the switch fork at the station of the subscriber called in the manual.



   If the local subscriber of the set B manual wishes to call back the long distance operator at the central office, he momentarily and repeatedly actuates his switch fork, which has the effect of momentarily opening and closing the 2340 relay circuit. The battery and earth from the windings of relay 2310 are momentarily connected to the talk leads of junction T-3 through the rest contacts of the armature blades 2341 and 2342 and the winding of the relay. 2330 causing the momentary attraction of the relay

  <Desc / Clms Page number 116>

 1070 of the TOS long distance office selector Fig. 10. Each time the relay is energized, it applies a ground from the incoming conductor C to the incoming conductor EC through the armature paddles IC62 and 1071.

   This has the effect of flashing the lamp 601 of the interurban operator's table indicating to the operator that the called subscriber wishes to converse with her. The operator then operates her key K-1 to connect the conversation conductors of her position with the conversation conductors of the established communication.



   Control of the artificial trunk line. When the call from a long distance operator of a remote long distance office is established by the long distance operator of the central office to an office belonging to the area of the central office, the artificial long distance line 214 is connected in the long distance line circuit.



   Disconnection supervision signal.



     When the conversation is over and the long distance operator at the remote long distance office is sending inrush current on the TL-1 long distance line, relay 270 responds and de-energizes relay 260. Finder relay 650 will release and de-energize Fl. will turn on light 602 to give the trunk operator at the central office the disconnect signal on the calling side of the call. When the subscriber called from manual office N 4 hangs up his receiver, relay 2340 of repeater 9-1 returns to its normal position thereby connecting the windings of relay 2410 to the conductors of junction T-3.

  <Desc / Clms Page number 117>

 



  The relay 1070 and the selector switch of the TOS long distance office are actuated and connect the earth potential via the armature pallet 1071 to the EC conductor and thus the lamp 601 lights up.



   The long distance operator having received the disconnection signal can then operate the K-11 key to release both sides of the call.



   When releasing the switch preceding the TOS interurban office selector Fig. 10, the earth is removed from the incoming conductor 0, thereby opening the. blocking circuit for relays 1040., 1050 and 1060 which release. When relay 1040 releases a circuit is established for the RLSE release solenoid and the switch is therefore returned to its normal position. When earth is removed from the incoming conductor C, relay 2270 releases. The circuit maintained through the right winding of the translator coil 1000 through the junction line T-3 for the relay 2410 of the repeater R-1 is opened by the armature pallets. 1053 to release relay 2410.



   Note, however, that if the called subscriber has not released the communication and if the relay 2340 is maintained in its attracting position, the relay 1070 of the long distance office selector will be de-energized. Therefore when earth is removed from the incoming conductor C by releasing the previous switch, the relays
1040, 1050 and 1060 indicated above are then kept attracted by a given earth by the reinforcing pallet 1046 of the relay 1040 attracted via the reinforcing pallet 1071 and the reinforcing pallet 1062. By con - sequent the selector of the TOS long distance office cannot be released by the long distance operator before the subscriber

  <Desc / Clms Page number 118>

 hung up his receiver.



   Suppose relay 1070 has been pulled due to the de-energization of relay 2340. L1 follows that armature paddle 1053 opens the circuit of relay 2410 which releases and opens the circuit of relay 2420 which releases with delay. Through armature paddle 2421, relay 2420 opens the blocking circuit of relay 2350. Relay 2350 releases through armature paddle 2358 and closes a circuit for lamp 2416. Note that when relay 2420 releases , a circuit is established from earth at the armature pallet 2404, the armature pallet 2423 to the coil of relay 2310. Relay 2310 draws and connects a ground through the armature pallet 2312 to the negative conductor of junction T-3 causing the attraction of relay 2260 of the associated junction circuit TC-1 Fig. 22A.

   Through the armature pallet 2261, the earth potential is applied to the conductor C to occupy the junction circuit while the operator B disconnects the repeater R-1 from the called subscriber icon.



   When operator B receives the disconnect signal, she removes plug P from the called subscriber's line jack to release relay 2400. The earth is removed from the winding of relay 2310 by the pallet. armature 2404 thereby eliminating the conditions of occupation of the selector benches of the long-distance office and opening the circuit of the lamp 2416 by the armature pallet 2408.



  Repeater R-1 is then returned to its normal position and is available for new calls.



   Reception of a subscriber number called before the repeater R-1 is connected to a device: free call indicator.



   The purpose of the 2340 relay will now be explained.



  Suppose the repeater R-1 has been entered, if it is not

  <Desc / Clms Page number 119>

 then associated with a free call indicator, relay 2440 cannot attract. The attraction of the relay 2420 closes a circuit through the armature paddle 2424 to cause the rotation electro of the call indicator selector to be attracted through the conductor 2375 and starting from the conductor 2373. However, it is possible that a free call indicator be associated with repeater R-1 before part of the first digit of the requested subscriber number is received by relay 2410. Therefore when relay 2410 releases the first time, a circuit is established from earth to the armature pallet 2411, the armature pallets 2422 and 2441, the winding of 2430 to the battery.



  Relay 2430 attracts and blocks by armature vane 2432 and armature vane 2433 at one point opens the circuit passing through conductor 2374. Therefore each time relay 2410 releases due to the remaining pulses of the first digit, the relay 2430 circuit is established, thus preventing the pulses of the first digit from being re-transmitted by conductor 2374 to control the call recorders / indicator equipment. If relay 2440 is attracted, it simultaneously prepares the pulse circuit through the front contact of the armature pallet 244L.

   After the pulses of the first train have been received, relay 2410 remains attracted for a longer time and release delay relay 2430 releases and again prepares the pulse circuit by conductor 2374 to the rear contacts of the switch. frame pallet 2433.



   Therefore when the remaining pulses are received by relay 2410, the call indicator equipment registers associated with repeater R-1 are actuated according to the received digits.

  <Desc / Clms Page number 120>

 



  * When lamp 2415 and the lamps of the indication panel are on in front of operator B, it will immediately know that one of the digits of the called subscriber's number has not been registered and therefore it operates its occupancy key. The 2480 relay attracts when the occupancy key (not shown) is operated and alerts the operator of the trunk table in the central office.



  The operator at the central office will then re-establish communication in the usual way.



   The local manual office subscriber in the central office area calls long distance.



   A description will now be given of a call made by a subscriber of the local manual office, for example the subscriber of set B of the local manual office N 4 to a subscriber of a remote long distance office accessible by the long distance line. TL-1.



   Suppose that the subscriber of set B has picked up his receiver and that operator A of local manual office no.4 has answered and routed the call through the trunk line T-2 to the MR circuit for manual recording of the Fig. 4. When operator A inserts her plug into the junction jack, relay 410 of the MR manual recording circuit is drawn through the loop of the circuit including the cord circuit of operator A. By the paddle. of reinforcement 412,? relay 410 establishes a circuit for the lower winding of relay 420 and through the armature pallet 411 the battery potential of the upper winding of relay 430 is connected to conductor 0-460 and its multiplication.

   Following the pull of relay 420, earth is applied to conductor 445 by armature paddle 442 to turn on the distributor of Fig. 12.

  <Desc / Clms Page number 121>

 



   It will be assumed that a CLR operator at the central office table has manipulated a talk key from a free seeker circuit and thereby marked her position.



  "free" to the distributor test circuit Fig.12. In addition, it will be assumed that the searcher has been chosen and found the calling line which in this case is the manual recording junction circuit of Fig. 4 and that the attendant has been warned by the switching on of the lamp. busy circuit and that moreover it received the tone of call.



   When the finder finds the manual record junction relay 430 is pulled when earth is returned to conductor 0 by the finder. Through the armature pallet 431, the relay 430 prepares a blocking / circuit for each of its windings in series with the conductor 0 grounded; by the armature pallet 433 it prepares a shunt circuit for the lower winding of the relay 410 and by the armature pallet 432 it establishes an excitation circuit for the relay 440.

   The relay 440 attracts and through the rear contact of the armature pallet 442, it opens the excitation circuit of the relay 420; it opens the conductor 445 by the reinforcement pallet 444; it prepares a blocking circuit for the relay 430 by the armature pallet 441 this circuit being now short-circuited by the circuit comprising the upper winding and it is blocked by the armature pallet 442 and its front contact. Due to the de-energization of relay 420, the high resistance of the lower winding of relay 410 is shunted out of the circuit loop and causes the supervisory lamp to go out in the operating position. Has manual office.

   The manual logging trunk lamp 450 is on to indicate to the trunk operator the trunk group on which the call was received.

  <Desc / Clms Page number 122>

 



   The long distance operator takes note of the call and talks with the operator of the manual office who made the call and receives the necessary information including the number of the calling subscriber and the number of the called subscriber.



   The operator position A cord circuit is not provided with the necessary equipment for long distance supervision. Consequently, the inter-city operator of the central office establishes a new communication for the subscriber calling from station B to the call indicator position of the table of the local manual office.



   The long distance operator at the central office can drop the calling subscriber and operator A and then route a new communication through the operator B position of call indicator to the subscriber who sent. the call.



   In this case, however, it will be assumed that the central office long distance operator maintains the first call while establishing a new call through the call indicator position from the manual office to the calling subscriber.



   Supervision on primitive communications.



   If operator A of the manual office wishes to call the long distance operator of the central office back, she momentarily and several times removes her plug from the junction jack, thereby causing the answer lamp of the connected searcher to flash. When the plug is momentarily removed, relay 410 releases opening the initial excitation circuit of the upper winding of relay 430 through armature pallet 411. Relay 430 remains in its engaging position via the

  <Desc / Clms Page number 123>

 blocking circuit comprising each of its two windings and resistor R-10.

   The resistance of the lower coil of the relay added to resistor R-10 now connected to lead 0 causes the finder supervisor relay to release and the response supervisor lamp to light.



   When operator A at the manual office reinserts the plug into the junction jack, relay 410 will draw again through the circuit loop and close the circuit through armature paddle 411 of the upper coil of relay 430, removing thus the high resistance circuit will start from conductor 0. When resistance is removed from the circuit comprising the lower winding of relay 650, the relay will be energized again and will open the circuit for lamp 603. central office will then operate the key K-1 to establish communication with operator A.



   When the long distance operator of the central office wishes to flash the lamp of the operator of the manual table, she operates the key K-1 to connect the key
K-7 momentarily, thereby connecting the battery and earth through contacts 1405 and 1404 and conductors 1445 and 1444 respectively to the conductors
653 and 654 and to the positive and negative talk leads of the incoming communication, causing the pull of the relay 420 in the MR junction circuit of manual registration of Fig.4. When this happens,

   the shunt of the high resistance lower winding of relay 410 is removed by opening the armature pallet 421 thereby introducing the high resistance lower winding of relay 410 into the loop of the circuit going. to operator position A in the manual causing operations in the cord circuit to turn on the supervision lamp. When operator A of the manual answers

  <Desc / Clms Page number 124>

 when the supervision lamp flashes, the long distance operator at the central office can give her the information she wants.



   Routing of a call by the answer side of a researcher.



   To allow the long distance operator to establish a communication through operator B of the manual office, a K-9 key has been provided.



     When the CLR operator operates the K-9 key, an earth is given by the contacts 1412 and by the intermediary of the conductor 1440 in the first level of the vertical benches accessible to the operator who answers. In addition, the earth given by the circuits 1410 is provided through the conductor 1449, the armature pallet 1344, the conductor 1302 to prepare the operation of a chosen finder, while through the contacts 1428 a ground is applied. to conductor 1451 to cause the operation of relays 1380 and 1350.



   In order to prepare the attendant equipment to route a return communication to the calling subscriber from the manual through the operator B position the operator CLR first operates the key K-3 Fig.ll to prevent other incoming calls from being received at its position. When this key is operated, the battery is removed from relay 1170 thereby preventing the relay from attracting to remove the protective earth from conductor 1188 going to the distributor of Fig. 12. Consequently, other calls cannot be received by the operator handling a deferred call.



   It will be assumed that the first call from operator A of the local manual office has been established at

  <Desc / Clms Page number 125>

 through a seeker similar to the finder F-1 of fig. 6 and that the communication established for the callback of the subscriber of the manual via the operator position.



   B is performed by the finder F-1 shown in fig. 6.



   With keys K-3 and K-9 in working position, the following operations take place: earth on contact
1410 is extended through conductor 1449, reinforcement pallets 1363 and 1344 up to the conductor
1302 to start the operation of a selected finder. Earth is applied through the. contact 1428 to the driver 1451 to activate the relays
1380 and 1350 via a circuit comprising the normally closed contacts controlled by the armature paddle 1392. The relay 1350 attracts and through the armature paddle 1351 at another point opens the circuit of the relay 1170.



   Due to the attraction of relay 1380, by the idle contacts of the armature pallet 1382, the conductor
606 is disconnected from the winding of relay 1370 and is connected through conductor 1318 and wire 3 to the EC bank contacts in the group of bank contacts for deferred call of line seekers LF-1 and LF-2 associated with the SL-1 and SL-2 transmitter circuits of the interurban operator position equipment; by the armature pallet 1385 the earth is placed on the conductor 1304 in order to attract one of the relays 1610 or 1630 depending on the circuit of the selected transmitter;

   by the frame pallet
1386 an excitation circuit is established for relay 1310 which extends conductors 653 and 654 through front contacts of armature pallets 1311 and 1312, conductors 1315 and 1316, of cable 3, to the bank contacts positive and negative contact group for deferred call

  <Desc / Clms Page number 126>

   to the benches of the LF-1 and LF-2 line researchers; by armature paddle 1387 the guard earth is removed from conductor F-1317 to mark the bank contacts for delayed call as "free".



   Suppose that grounding conductor 1304 causes relay 1610 to operate, which causes the SL-1 transmitter circuit to operate to connect a free recorder transmitter to the transmitter circuit through the switch selector. - transmitter SS-1 and to connect the circuit of the transmitter SL-1 and the selected free transmitter-recorder to the equipment of the operator position through the bank contacts for deferred call associated with the circuit of the FL-1 researcher.



   The operation of the SL-1 transmitter circuit, fig. 15, has been described above and it is understood that when brushes 1522-1527 have arrived at the bank contacts connected to conductor 1315 to 1319 no earth potential will be encountered on conductor F-1517 and the short circuit is removed from relay 1510 which will attract with the LFM electromagnet to stop the progression by brush steps. All F conductors are grounded to prevent the LF-1 finder from entering a finder circuit while searching for a group of delayed call bank contacts that is marked.

   These contacts will either be grounded through the rear contacts of the 675 armature paddle of the disconnect relay or if a finder was previously entered, and used for communication, the F conductor will be grounded through of the connected conductor C and the front contacts of the armature pallet 675 of a drawn connection relay.



   When the SL-1 transmitter circuit has finished its

  <Desc / Clms Page number 127>

 operation, the lamp will light up to indicate to the long distance operator that the equipment is ready to send pulses.



   The long distance operator then chooses a free searcher by manipulating the conversation key, ie K-1 associated with the searcher. The finder F-1 then operates in the manner previously described but in this case the vertical movement stops at the first level due to the marking potential applied to the vertical brush. The researcher searches this level to find a free deferred call selector.



   Suppose that the first TFS-1 long distance selector in fig. 7 (to which we will refer during this communication as a deferred call selector) is the first that is found free and that it is seized by its incoming conductors. Relay 610 is then drawn through a circuit comprising its upper winding, armature paddle 623, lower coil of relay 650, to earth at armature paddle 634 and connects negative 1, positive 1, brushes 0 -1 and EC-1 of the group of brushes 618 to the incoming conductors 771, 772, 773 and 774 of the delayed call selector of fig. 7.



   As relay 630 attracted and blocked, battery potential was applied to conductor 608 causing relay 1340 to operate. Through armature vane 1342, relay 1340 established a blocking circuit for the top winding of the battery. relay 1380 and the ground potential applied to conductor 1302 is transferred from key K-9 to the front contact of armature paddle 1342. As another effect of the pull of relay 630 a circuit is established by the armature paddle 636 to turn on the lamp 603.

  <Desc / Clms Page number 128>

 when the long distance operator notices that the lamp 603 is on, she operates her sending keys DK to register the trunk group number and the number of the calling station B. The recording and retransmission of digits takes place in the manner previously described .



   The first TFS-1 long distance selector responds to the first group of pulses, raising its brushes to the second level of its associated bank contacts, and the brushes automatically begin to rotate in search of a long distance office selector. free.



   It will be assumed that the selector for deferred call seizes the long-distance office selector TOS by the intermediary of the pads 1015 shown in FIG. 10. The TOS selector attracts in the manner previously described and responds to the second group of pulses composing the second digit 4 by raising its brushes to the fourth level of its associated bank contacts.



   TOS long distance office selector brushes 1016 scan the fourth level bank contacts for a free trunk circuit analogous to the trunk circuit TC-1 shown in fig. 23 and connected to a junction line between free offices such as the junction line T-3 leading to the repeater R-1 of fig. 24 and 25 in the manual office N 4.



   Assume that the first free trunk circuit reached by the TOS toll office selector brushes is trunk circuit TC-1 of FIG. 23.



   When this occurs, the junction circuit is put into service as previously described and extends the loop of the pulse circuit to the repeater R-1 in the manual office. when the circuit loop is extended to

  <Desc / Clms Page number 129>

 repeater R-1 of fig. 24 and 25, the circuit is established for the relay 2210 which follows the received pulses and causes the operation of the call indicator equipment as previously described.



   When the SL-1 transmitter circuit, fig. 15, has finished retransmitting the recorded digits, relay 1530 draws and connects the battery potential through resistor Rl and armature paddle 1532 to brush EC-1525 to attract relay 1050 of the TOS long distance office selector, fig. 10.

   This circuit can be indicated by starting from the battery to the EC-15.25 brush, the conductor 1318 and the cable 3 connected to the deferred call bank, the reinforcing pallet 1382, the conductor 606 and the cable 1, the reinforcing pallet 664, shaft contacts 627, brush EC-1 of group of brushes 618, conductor EC-774 passing through the delayed call selector, fig. 7, to the incoming driver EC of the TOS long-distance office selector, fig. 10, the armature pallet 1044, the space contacts 1095, the normally closed contacts controlled by the armature pallet 1056, the top winding of the relay 1050 to the battery. The relay 1050 attracts and introduces the translator coil 1000 in the manner previously described.



   In addition, the relay 1530 of the SL-1 transmitter circuit also closes the test circuit by the attraction of the armature paddle 1531, through the armature paddle 1533 a ground is connected to the brush 1526 thereby causing the attraction of relay 1390 from the operator position relays, fig. 13, and by the armature pallet 1535 the circuit of the lamp 1500 is opened to turn off the lamp.



   After the long distance operator has maneuvered her DK sending keys according to the trunk group number and the

  <Desc / Clms Page number 130>

 number of the calling subscriber and after the momentary operation of the transmitter disconnection key, it operates the K-16 key. Operating the K-16 key connects the battery through resistor R-7, contacts 1411, contacts 1427, conductor 1452 to the armature paddle 1394 of relay 1390. The K-16 key is provided in order to give operator B in the manual office a flashing signal indicating that she can plug into the jack of the calling line without performing the usual busy test.



   Due to the attraction of relay 1390 the circuit comprising the lower windings of relays 1350 and 1380 is opened by the normally closed contacts controlled by the armature pallet 1392 and by the armature pallet 1391 the relay 1390 opens the circuit of blocking of the upper winding of relay 1380. Relays 1350 and 1380 both release and through the armature pallet 1386 relay 1380 opens the circuit of relay 1310.

   Before relay 1310 has had time to release, the battery potential applied to conductor 1452 extends through the armature paddle 1394 of the relay 1390, the armature paddle 1312, the conductor 654 and cable 1, to the negative conversation conductors of the finder Fl, the deferred call selector (selector TFS-1) of fig. 7, the upper left winding of the translating coil 1000 (TOS selector in fig. 10) via the armature pallets 1041 and 1051, the armature pallet 1057, through the coil of the relay 1090 down to earth. This battery potential is only momentarily applied until relay 1310 releases and transfers leads 653 and 654 to leads 1180 and 1181.



   When de-energizing relay 1380, the battery applied to the EC driver of the long distance office selector

  <Desc / Clms Page number 131>

 TOS through armature pallet 1382 and conductor 606 is transferred to the rear contacts of armature pallet 1382 and now includes the winding of relay 1370. By armature pallet 1381, earth is removed of the driver KC-1356 to release the finder F-1 of the equipment from the position when the conversation key K-1 is returned to its normal position and if it has not been returned to its normal position the seeker F-1 is kept under the control of the operator by the K-1 conversation key.



   In the TOS trunk switch of fig, 10 when the battery is momentarily applied to the incoming negative conductor and causes the pull of the relay 1090, the earth applied to the negative brush of the brush group 1016 by a ground given by the paddle armature 1091. This earth is extended through the negative pads 2250 of the TC-2 junction circuit, fig. 22A, the negative talk conductor of junction T-3, the armature paddles 2312, 2351 and 2341, the lower winding of the relay 2330, the normally closed contacts controlled by the armature paddle 2355 , the lower winding of relay 2410, towards the battery.

   This circuit holds relay 2410 and because of the shunt of the top winding of relay 2330 and the top winding of relay 2410 by the same earth applied by the armature vane 1091 no current is flowing through the top winding of the relay. relay 2330 or in the upper winding of relay 2410.



  Relay 2330 is then attracted because no current is flowing through its upper winding while a drive circuit is established for its lower winding. When the 2330 relay is pulled in, a circuit is then established for the 2490 relay by an earth given by the ar-

  <Desc / Clms Page number 132>

 mature 2321, the winding of relay 2490 to the battery.



   Relay 2490 draws through this circuit and is blocked by armature pallet 2491, armature pallet 2403, and a given earth by armature pallet 2421.



   As a further effect of this attraction, relay 2490 connects conductor 2377 through armature paddle 2492 to lamp 2415 and to the battery. When this circuit is closed lamp 2415 gives a flashing signal to operator B to indicate that the line which was called by the operator at the central office is busy and that the subscriber is waiting for his communication to be established. When operator B inserts plug P into the jack of the calling subscriber's line, the conversation will then be established with the long distance operator via operator B's table, junction T- 3 and the switching devices described.



   Operator B connects to the line of the calling subscriber,
Since the communication is routed by the CLR operator, relay 2450 of repeater R-1 of fig. 24 and 25 is not automatically attracted at the end of the transmission of the digits via the transmitter circuit SL-1 of fig. 15. The inrush current produced by the CLR operator position is controlled by the operation of the K-13 key.



  However, in this particular type of call, the subscriber does not hang up his receiver while the long distance operator at the central office calls him back and therefore it is not necessary to ring on the subscriber's line.



   When operator B plugs plug P into the jack of the called subscriber (not shown), relay 2400 is drawn.



  Through the armature paddle 2407 the relay 2400 establishes a circuit for the relay 2350 thereby reversing the direction of the current in the junction line T-3 and causing the

  <Desc / Clms Page number 133>

 operation of relay 1060 in the TOS long distance office selector, fig. 10. Relay 1060 is blocked by the incoming conductor from its grounded lower winding and by rebar 1061 it places a shunt on its upper winding to remove the upper winding of the conversation conductors from the junction.



  Relay 1070 draws through the loop of the circuit including battery and earth to relay 2410 and connects earth through armature paddles 1062,1071 and 1056, clearance contacts 1095 and armature paddle 1044 to con- EC driver. The earth applied to the EC conductor is extended through the EC brush of the group of brushes 770 of the delayed call selector to the EC brush of the brush group 618, the shaft contacts 627, the armature pallet 664, the conductor 606, cable 1, armature pallet 1382 to the relay coil 1370 and the battery. Relay 1370 attracts and through armature paddle 1371 connects a ground to conductor RL-607 to cause lamp 602 to be ignited.

   The lamp 602 lights up momentarily to signal to the long distance operator that operator B has routed the call to the line of the calling subscriber.



   The above stated operation effecting the ignition of the lamp 602 is controlled by the pull of the relay 2250 of the repeater R-1 which in turn is controlled by the armature paddle 2407 of the relay 2400. By the paddle armature 2401 of relay 2400 a circuit is also closed for relay 2340. However the setting of armature paddles 2401 and 2407 is such that armature paddle 2407
2401 closes its contact before the rebar / closes its front contact. When the armature pallet 2401 closes the circuit with its front contact, the relay 2340 is attracted by the circuit loop including the line from station B. The relay

  <Desc / Clms Page number 134>

 2340 attracts and de-feeds the T-3 junction.



   The TOS long distance office selector relay 1070 of fig. 10 returns to its normal position when the T-3 junction circuit is de-energized and removes the earth of the incoming conductor EC from the TOS selector thereby causing the release of relay 1370 and opening the circuit of the lamp 602.

   It should be noted from the above description of the operation of relays 2350 and 2340 that the slight delay between the operation of relay 2350 and the subsequent operation of relay 2340 is sufficient to allow reversal of the current direction. in junction T-3 and thereby to remove the resistance of the top winding of relay 1060 of the conversation circuit and also burn a signal to the long distance operator to indicate that operator B has routed the call to line of the calling subscriber before the T-3 junction is de-energized.



   Calling subscriber callback.



   If the calling subscriber has hung up his receiver, the long distance operator can call the subscriber back by operating key K-7 in fig. 14. When the key K-7 is momentarily operated, an earth is applied to the conductor 1443 to cause the attraction of the relay 1310 thereby extending the conductors 853 and 654 by the intermediary of the armature paddles 1311 and 1312 and the conductors 1445 and 1444 towards the battery and the earth by contacts 1405 and 1404. The battery and the earth are extended by means of the positive and negative brushes of the Fl researcher, fig. 6 and the first TFS-1 interurban selector in fig. 7 respectively to the positive and negative conductors of the first TOS interurban selector of FIG. 10.

   The battery potential applied to the positive conductor is extended via

  <Desc / Clms Page number 135>

 of the armature pallets 1042 and 1054, the lower left hoarseness of the translator coil 1000, the armor pallet 1052, the winding of the relay 1080 to earth. The earth connected to the negative conductor has no effect at this time. The relay 1080 is momentarily attracted and by the armature paddles 1081 and 1082 connects the generator of the inrush current through the positive and negative brushes of the 1016 brush group to the T-3 junction line causing this causes the attraction of the relay 2320 by the repeater Rl.

   The 2320 relay draws in and through the armature paddle 2321 establishes a circuit for the relay 2450 which is blocked through the armature paddle 2453 and the ground given by the armature paddle 2421. By the paddles of armature 2451 and 2452 relay 2450 establishes the inrush current circuit to the subscriber line.



   When the subscriber responds by picking up his receiver, relay 2460 attracts and disconnects the inrush current and relay 2340 is drawn by the loop of the subscriber circuit.



  The pulling of relay 2340 cuts off power to junction T-3 thereby causing the release of relay 1070 of the TOS selector and it follows the extinction of the lamp 602 at the trunk operator table.



  Restoration of the answer key to its normal position,
When the long distance operator receives the answer signal, she returns her K-9 key to its normal position. When earth is removed from conductor 1451 by opening contacts 1428 of the K-9 key, relay 1390 returns to its normal position causing the reapplication of earth to conductor 1304. Relay 1630 attracts and turns on the circuit. the SL-2 transmitter looking for a free recorder and the chosen F-1 finder. By contacts 1412, the key K-9 removes the ground of the conductor 1440 and by the

  <Desc / Clms Page number 136>

 contacts 1410 earth is removed from conductor 1449 while through contacts 1411 battery potential, applied through contacts 1427 of key K-16 is removed from conductor 1452.



   The SL-2 transmitter circuit then functions in the same way as previously described to find free recorder-transmitter equipment and to connect the seized recorder-transmitter equipment to the finder who is connected to the data line. the calling subscriber of station B. The researcher F-1 is marked on the banks of the circuit of the researcher LF-2 by the absence of an earth on the conductor F-1557 which is multiple on the banks of the circuits of the researchers LF-1 and LF-2. Since the LF-2 seeker circuit is the only one in service, it finds the seeker-selector circuit made up of seeker F-1 in fig. 6 and the first TFS-1 interurban selector in fig. 7, and prepares the TFS-1 switch to operate in the same way as described above.

   Lamp 1600 turns on when the recorder-transmitter equipment is connected to the searcher-selector circuit. The recorder-transmitter equipment is then connected to the calling side of the searcher circuit and the long distance operator then operates her send keys DK according to the selection number of the trunk of the long distance line terminating at the remote office.



   In the communication described, the desired trunk line is trunk line TL-1 of FIG. 1 which is reached by the operation of the sending keys 1 and 3. Immediately after the operation of the keys 1 and 3, the interurban operator operates the transmitter disconnection key which causes the operation of the disconnection relay of the transmitter. SL-2 transmitter circuit and prepares the transmitter circuit to disconnect recorder-transmitter equipment.

  <Desc / Clms Page number 137>

 transmitter connected immediately after the stored digits have been retransmitted.



   The first TFS-1 long distance selector in fig. 7 responds to the first train of pulses which is in this case the number 1 by raising its brushes to the first level of its associated bank contacts and by turning them automatically in search of a free trunk line selector. . Suppose the first TLS-1 trunk line selector in Fig. 9 is the first that is found free, it will be seized by means of the pads connected to the conductors 912-915 of the banks of the TFS-1 selector. The TLS-1 trunk line selector in fig. 9 responds to the second train of pulses forming the second digit 3 by raising its brushes to the third level of its associated bank contacts and automatically spinning them in search of a free trunk line circuit.

   It will be assumed that the circuit of the trunk line TLC of FIG. 2 is the first found free, it is then entered by means of the studs 275 shown in FIG. 2.



   The circuit of the TLC trunk line in fig. 2 is entered in the manner described above and the interurban operator having observed the extinction of the lamp 1600 operates the key K-13. Through the contacts 1421, the key K-13 applies the battery through the conductors 1446, the armature pallet 1321, the conductor 656 to cause the attraction of the relay 230 of the trunk line circuit TLC of fig. 2. Relay 230 draws and transmits inrush current over the TL-1 trunk line to alert the remote operator.



   When the remote operator answers the long distance operator at the central office indicates the number of the desired subscriber. The remote operator establishes communication

  <Desc / Clms Page number 138>

 to the called subscriber and when the subscriber answers, the long distance operator at the central office restores her conversation key K-1 to its normal position thereby disconnecting the blocking circuit of relay 670 which returns to its normal position and which removes the operator's conversation leads from the established call and also releases the relays drawn into the position equipment.



  The calling subscriber from station B of manual office No. 8 can then converse with the called subscriber of the remote long distance office.



  When the conversation begins, the long distance operator at the central office marks the long distance record to indicate the moment at which the conversation started.



   Release of operator A.



   The long distance operator of the central office can then release the premitive call established by operator A of manual office n 4. In order to carry out this operation, the long distance operator operates the searcher's conversation key which is still connected to the call circuit. MR manual recording junction in fig. 4. This researcher is marked at the central office operator position by switching on the occupancy lamp associated with it.

   After the attendant has operated the conversation key associated with the connected searcher, she then operates the K-8 key. thereby connecting earth through contacts 1408 and conductor 608 to bypass relay 1340 and the changeover relay. When the change-over relay releases it prepares a circuit for the finder-finder release electromagnet.

   The finder-start relay releases when earth is removed from conductor 1302 due to the de-energization of relay 16 = thus establishing the circuit of the connected finder-release electromagnet. When the release electromagnet operates, the finderscope returns to its normal position, due to the finder finder returning to rest

  <Desc / Clms Page number 139>

 earth is removed at pin 460-C thereby causing relay 430 to de-energize. Relay 430 releases and through armature paddle 433 removes the high resistance lower winding shunt of relay 410 causing the relay to drop. the operator's position supervisory lamp A on the manual table is switched on to give operator A the disconnection supervision signal.

   Operator A removes her cord from the jack on the calling subscriber line and from the jack connected to trunk T-2.



   When operator A removes her plug from the jack connected to the T-2 junction line, relay 410 returns to its normal position and through the armature paddle 412 opens the blocking circuit of relay 440. Relay 440 releases and returns the circuit to its normal position. The trunk attendant at the central office brings the release key back to the K8 answer side and the searcher talk key released when the circuit busy light is off.



   Supervision signal by the switching fork. of the calling subscriber of the manual.



   If the subscriber calling from the manual of station B wishes to call back the long distance operator of the central office, he momentarily and repeatedly operates his switch fork opening and closing the circuit of relay 2340 of the repeater R-1, figs. .24 and 25.



   The battery and ground of the windings of relay 2310 are momentarily applied to the conductor of junction T-3 through relay 2330 and the left windings of the translator coil 2360 thereby causing the momentary attractions of relay 1070 in the 'TOS long distance office selector, fig. 10. As noted above anytime the 1070 relay released ground is applied to the incoming LC conductor. This land is extended

  <Desc / Clms Page number 140>

 through the deferred call selector via its brush EC and the incoming conductor EC-774 to brush EC-1 of group of brushes 618 of finder F-l, freeze 6.



  In finder F-1 the earth is extended further through shaft contacts 627, normally closed contacts controlled by armature paddle 664 to lamp 602 and battery. This lamp lights up momentarily each time the 1070 relay attracts. The operator of the central office can connect her conversation conductors to the communication by operating her conversation key K-1.



   The calling subscriber can then converse with the long distance operator at the central office.



   Control of the artificial trunk line. When communication is established between the trunk operator at the central office and the remote trunk operator by trunk line IL-1, the artificial trunk line 214 of the trunk line circuit TLC of FIG. 2 is connected in the trunk line circuit for the purposes described above.



   End of communication supervision signal.



   When is the subscriber calling from the manual office? 4 hangs up its receiver at the end of the conversation, repeater R-1 relay 2340, fig. 24 and 25, releases and reapplies the battery to the conductors of the T-3 junction causing the pull of the relay 1070 in the TOS selector of the fig, 10. The lamp 602 is permanently on to give the long distance operator from the central office the end of communication supervision signal and it again proceeds to the marking of the long distance card to indicate the time during which the calling subscriber used the long distance line.

  <Desc / Clms Page number 141>

 



   The long distance operator of the remote long distance office sends inrush current on the TL-1 long distance line when the called subscriber hangs up thereby causing the pull of relay 270 and therefore de-energization of relay 260. When relay 260 releases the circuit is established by the upper winding of the relay 280 which by pulling connects a ground to the conductor EG-279. This earth is extended through the EU conductors of the TLS-1 trunk selector, of the first TFS-1 trunk selector, fig. 9 and 7, respectively, thereby causing the lamp 601 to come on.



   Having received the end of communication signal, the long distance operator can then operate the K-1 key to associate her equipment with the communication and then actuates the K-11 key to restore all the switching devices to their normal position.



   Transferring a call.



   This type of communication typically occurs as a result of repeated attempts by the operator at the central office trunk table to establish a communication from a calling subscriber from the local office in the central office area to a subscriber in a remote office. and usually happens for person-to-person calls. When the attendant reaches the requested set but is unable to reach the called party, she can notify the called set that the called subscriber will get in touch with her as soon as he returns.



  The operator at the central office then warns the calling subscriber that she will call him back when the called subscriber is switched off.



   When the called subscriber returns he makes this call, the operator at the far end of the TL-1 trunk line routes the call and rings on the TL-1 trunk line to cause the operation of relay 270.

  <Desc / Clms Page number 142>

 in the circuit of the TLC interurban line, fig. 2. A researcher finds the circuit of the calling trunk line TLC of fig. 2. The operator of the internal position receives the information from the remote operator and operates her sending keys to route the call to the operator in question first and whose number is for example 942. .



   It will be assumed that the operator will operate her sending keys from her position to send the digits 9,4 and 2 thereby causing the brushes of the first TFS-2 interurban selector to be raised, fig. l, up to the ninth level and the rotation of the brushes on the benches in search of a free transfer selector TS in fig. 1 or the transfer selector in fig. 9. The transfer selector TS raises its brushes to the fourth level of its banks due to the four pulses making up the number 4 and turns the brushes by two steps due to the pulses of the number 2 to choose the transfer circuit between position ITC of fig. 1 and 5 which is specific to the operator position requested.



   The TS transfer selector, fig. 9, having been chosen the relay 930 is attracted by the C-914 grounded conductor through the head contacts 991. and the relay 910 is attracted through the conversation conductors and through the pulse contacts of the relay transmitter circuit pulses. Relay 920 attracts due to the attraction of relay 910. Relay 940 is also attracted by conductor C-914 grounded through armature paddle 932. When the pulses composing the second digit 4 are received by relay 910, it momentarily releases four times in a row.

   The GREEN ascent electromagnet responds to the pulses given by relay 910 through the armature paddles 911, 924 'and 923 and raises the brushes 990

  <Desc / Clms Page number 143>

 up to the fourth level of his bench. The lower coil of relay 930 keeps the relay attracted after its upper coil has been disconnected at head contacts 991 due to the first vertical pitch of the brushes.



   At the end of the pulse trains the relay 950 releases and opens the initial circuit of the relay 940 by the armature pallet 932 but this relay remains attracted by its blocking circuit comprising the armature pallets 942 and 946.



  Through the armature paddle 933 the relay 930 transfers the operating circuit from the GREEN ascent electromagnet to the rotation electromagnet ROT through the relay 950, the armature paddle 944 and the normally closed contacts controlled by armature pallet 964.



   When the pulses of the last digit 2 are received by relay 910 the ROT rotation electromagnet circuit closes twice. The ROT rotation electromagnet rotates the brushes 990 by two steps to engage them on the group of contacts 560 of the transfer circuit between position ITC-2 fig. 5. Relay 950 attracts in series with the rotation electromagnet ROT from the first rotation pulse. Pulling relay 950 disconnects brush C-990 by armature paddle 951 and pulls relay 960 by armature paddle 952. Relay 960 disconnects brush BC-990 and opens relay 940 blocking circuit .



  Through the front contact of the armature pallet 964, the relay 960 closes a new rotary feed circuit that does not depend on the armature pallet of the relay 940.



   At the end of the pulse trains controlling the rotation, the relay 950 releases and through the armature pallet 952 it disconnects the operating circuit of the relay 960.



  By armature paddles 951 and 965 the C-990 brush is reconnected to the test winding of relay 980.

  <Desc / Clms Page number 144>

 



   Suppose that the transfer circuit between position ITC-2 in fig. 5 is free when the brushes 990 arrive on the pads 960, the test winding of the relay 980 will be energized by the conductor C through the armature paddles 541, 532 and the winding of the relay 510. By attracting the relay 980 stops the rotational movement and it extends the incoming positive and negative and the EC conductors to the transfer circuit between position ITC-2, moreover by closing the blocking circuit for its middle winding, it applies a ground to the brush C- 990 through the armature paddles 983, 951, 941, 951, 965 and 971 as a shunt of its test winding to keep the transfer circuit between positions from any further input.



   Relay 910 releases and at the end of a certain time interval relay 920 releases. The selector remains attracted to a ground provided by the incoming conductor C-914 from the preceding selector.



   Due to the attraction of the relay 510 a circuit is established by the armature paddle 511 to turn on the lamp 561 at the desired operator position, thereby indicating to the operator that a call is transferred to her. Through the armature pallet 512 the relay 510 prepares a circuit for the lower winding of the relay 520; the armature pallet 513 it prepares a blocking circuit for the relay 520 and through the armature pallet 514 it prepares a grounding circuit for the conductor 524 in the first level of the researchers associated with the operator position requested.



   When the lamp 561 is on, this operator operates a conversation key associated with the free seeker circuit. One will assume that the conversation key K-1 associated with the researcher F-1, fig. 6, or the one that was chosen. When the K-1 key is actuated, relay 670 pulls in and the following circuit is established starting from earth to

  <Desc / Clms Page number 145>

 the lower winding of the relay 520, fig. 5, the armature pallet 512, the conductor 515 passing through fig.ll, to the armature pallet 1363 of fig. 13, the armature pallet 1344, conductor 1302 and cable 1, armature pallet 677, winding of relay 660 to the battery.



  The relay 660 draws in series with the relay 520 to start the searcher looking for the transfer circuit between position ITC-2 in fig. 5. The relay 520 by attracting establishes a blocking circuit for its upper winding, by the armature pallet 525 it places an earth on the conductor 524 to mark the first level of the contacts .du vertical bench associated with the finder of fig.6; and by the armature pallet 522 it connects the battery of the upper coil of the relay 530 to the pin C-570 to mark the line as "calling" to the researcher benches, fig.6.



   Since this call is received by an operator at a trunk table position, the K-3 key is in a working position. The conductor 524 and the junction conductors of the transfer circuit between positions are common to all searchers accessible only by the position of the table indicated above.



   The finder F-1 in fig. 6 responds to the operation of relay 660 and raises its brushes to the first level where the vertical test brush 617 meets the grounded conductor 524 which has the effect of stopping the vertical movement of the switch and replace with rotational movement. The brushes rotate by one step up to the first group of bank contacts of the first level to which the junction conductors of the transfer circuit between positions of fig. 3 are connected.

   The battery found on conductor 0 of the pads 570 of the bench par. the brush 02 of the brush group. 618 causes the attraction of the relay 620 con-

  <Desc / Clms Page number 146>

 thereby necting the negative 2, the positive 2, the brushes 02 and EC2 of the group of brushes 618 which are engaged at this moment on the pads 570 of the transfer circuit between positions of FIG. 5. The circuit comprising the upper winding of relay 530 and the upper winding of relay 620 causes the pull of the two relays in series. The F-1 finder draws in the same way as described above.



     , when the communication routed by the internal attendant enters the transfer circuit between positions, fig. 5, the earth applied to the incoming conductor EC by the armature paddle 531 turns on the call supervision lamp associated with the searcher used by it to establish communication.

   The illumination of the call supervision lamp is an indication to the interior attendant that the call has been routed to the desired operator position. When the finder F-1 of this operator position finds the transfer circuit between positions, fig. 5, and causes the pull of relay 530, ground is removed from the EC conductor to turn off the call supervision lamp at the inside attendant position as an indication that the desired operator position has responded.



   As a further result of the pull of relay 530, relay 510 releases and opens the blocking circuit of relay 520 which also releases. Lamp 561 in the desired operator position goes out and earth is removed from conductor 524. Through armature paddle 533 relay 530 establishes a circuit to operate relay 540, this relay being blocked by the incoming conductor. C and the armature pallet 542. The resistance of relay 540 is high enough to prevent entry of the transfer circuit between position by another transfer selector keeping this

  <Desc / Clms Page number 147>

 makes the transfer circuit of fig. 5 of any seizure since it is busy. Through the armature pallet 534 the relay 530 prepares a circuit for its lower winding.



  Due to the energization of the high resistance relay 540, the armature vane 543 establishes a multiple blocking circuit for the upper winding of the relay 530 thereby bypassing the circuit comprising its lower winding, the armature vane 534. and resistance R-10.



   When the call supervision lamp in the interior attendant position is off, the attendant immediately disconnects her headset from the communication established by returning her conversation key associated with the connected circuit to its normal position carrying this makes the communication received by the TL-1 trunk line directly to the desired operator position. This operator answers the call and receives the necessary information from the long distance operator who made this call.



   The first of these two operators checks through the long distance card which subscriber in the central office area has tried to establish a call with the subscriber of the remote long distance office. It then forms this subscriber number with the sending keys to route the communication to this subscriber line and then operates its call key K-13 to ring the device of the requested subscriber.



   When the subscriber answers the operator warns him that she has established the connection he had previously requested.



  The operator disconnects from the conversation conductors of the junction by bringing back her K-1 key and the subscribers are in communication. The operator then proceeds to mark the long distance record to indicate the moment of the start of the conversation and supervise the call in the usual way.

  <Desc / Clms Page number 148>

 



   End of communication supervision signal,
The local subscriber in the central office area hangs up his receiver after the conversation is terminated, thereby causing lamp 601 to light up in the operator position in order to give the end of communication supervision signal. usual. The attendant then operates her conversation key K-1 from the connected researcher F-1 to make sure that the subscribers have hung up.



   After trying the line and finding that the call has been cleared by both subscribers, the attendant operates the K-11 key thereby causing the calling and called sides to reestablish their train of switches in their normal position.



   The operator again marks the long distance record to indicate when the conversation ended in order to establish the cost of the long distance call obtained to be paid by the local central office subscriber.



   The researcher F-1, fig. 6, returns to its normal position when the K-11 key is operated and removes the earth from stud C-570 of the transfer circuit between position ITC-2, fig, 5.



   When this occurs the relay 530 releases and through the armature pallet 531 applies a ground to the incoming conductor EC. The application of the earth to the EC conductor causes the lighting of the call supervision lamp in the interior operator position to give an end of communication signal.



   Before cutting off the call at her position, the inside operator sends inrush current over the TL-1 trunk line to give the remote inter-city operator the end signal. It then operates its key similar to key R-11 and the set of switches that it controls is released in the usual manner.

  <Desc / Clms Page number 149>

 



   When this key is operated, the finder returns to its normal position and removes the earth of conductor C connected to pad 297, fig. 2, thereby releasing the trunk line circuit TLC, fig. 2. As a further result of the operation of the call and release key on the answer side, the first toll selector TFS-2 returns to its normal position and disconnects its brushes from the transfer selector TS. When the TS selector brushes have returned to their normal position, earth is removed from pin C-560 of the inter-position transfer circuit, Fig. 5, thereby allowing the high resistance relay 540 to release.



   Monitoring of established communication.



   If the operator wishes to monitor the established communication, she operates the key K-2 thereby connecting the conversation conductors corresponding to the head and the neck of the plug to conductors 1366 and 1365 and the earth being applied to the conductor 1357 via springs 692. The earth of conductor 1357 is extended via cable 1, reinforcing pallet 1334, conductor 1182, reinforcing pallet 1134 and the winding of relay 1120 towards the drums. The pulling of relay 1120 connects the operator's receiver to the secondary winding of the RC translator slide instead of its normal connection to the secondary winding of the induction coil I thus effectively providing a circuit. surveillance cooked.

   The operator can then listen to the conversation established to ensure that the communication is satisfactory without disturbing the connected subscribers.



  When the K-2 key is restored to its normal position, relay 1120 returns to its normal position and disconnects the operator's receiver from the secondary winding of the RC translator coil.

  <Desc / Clms Page number 150>

 



   Emergency devices.



   Emergency devices are provided to have a bypass on the distributor of fig, 12; to shut down one or both of the transmitter circuits SL-1 of fig, 15 and SL-2 of fig, 16 if one or both of them should be momentarily defective; and to transfer the operator control conductors to an adjacent position in the event that a position is not served when calls remain to be released.



   If the dispenser of fig, 12 makes a mistake, the operator can control her equipment so that a chosen finder can be operated to find a calling line. The relay 1210 of fig, 12 is pulled when a call comes in and turns on the response lamps at the operator positions. Let us suppose that the operator having access to the searcher F-1 of fig, 6 has manipulated his key K-1 to allow the seeker to find the calling line.



  However, due to the fault with the distributor in fig. 12, earth is not applied to conductor 1187 to cause the attraction of relay 660. The attendant having observed that the calling line is not connected to its position operates the K-10 unstable key. Earth is then applied to the conductor 1449 passing through the springs 1413 of the K-10 key, the conductor 1449, the reinforcing pallets 1363 and 1344, the conductor 1302 and cable 1, the reinforcing pallet 677, winding relay 660 to the battery. Pulling relay 660 causes finder F-1 to operate in the usual way to find the calling line.

   When the brushes 618 have risen to the level on which the calling line is located the relay 630 attracts and blocks by the battery to the armature paddle 632 and the resistor R-4, in addition

  <Desc / Clms Page number 151>

 this battery potential is extended by conductor 608 and cable 1 up to the winding of relay 1340 and earth.



  The relay 1340 attracts by this circuit and by the front contact of the armature pallet 1344 applies a direct earth to the conductor 1302. The operator is warned that this operation has taken place by the lighting of the lamp 603 which is controlled by pallet 636 and it will reset its K-10 emergency key to its normal position.



   The following operations of the finder are the same as those described.



   If the SL-2 transmitter circuit becomes faulty, the operator may notice by observing lamp 1600 that this circuit is not functioning correctly. When this takes place, it operates the key K-4 of fig. 16 to open the normally closed contacts of the N 1 transmitter cut-off springs called and thereby prevent relay 1620 from attracting to prepare relay 1630 circuit.



  Since no blocking circuit then exists for relay 1610, relay 1610 pulls whenever the control conductor of transmitter 1304 is grounded to the position equipment, thereby causing the operation of the SL-1 transmitter circuit instead of alternating with the operation of the SL-2 transmitter circuit.



  When this situation exists, the operator must refrain from operating a conversation key during a period of occupation of a free circuit following the acceptance of a new call until the pilot light 1500 which illuminates weakly. - ment is extinguished by releasing relay 1530 to indicate that the previously stored number has been completely retransmitted and that the transmitter circuit is released
In the event that it is the SL-1 transmitter circuit instead of the SL-2 transmitter circuit that becomes faulty,

  <Desc / Clms Page number 152>

 the operator can place the key K-4 in the opposite working position to close the normally open contacts of the switch-off device of transmitter N 2. In this case, relay 1620 is kept attracted each time by driver 1190.

   Whenever conductor 1304 is grounded relay 1630 will pull through contact 1623. With relay 1630 pulling alone whenever the transmitter control conductor is grounded, the transmitter circuit SL- 2 is used for each call instead of being used alternately with the SL-1 transmitter circuit.



   If an operator in any of the positions of the table finds it necessary to leave her position, at a time when a call remains to be released, she operates her key K-17, fig. 13, thus causing the attraction of relay 1330.



  By the reinforcement pallets 1331 to 1335 inclusive, the relay 1330 transfers the conductors 1366, 1365, 604 and 605 to the adjacent operator positions so that the operator who will succeed her can talk or monitor on the unserved position, the end of current communications.


    

Claims (1)

R E V E N D I C A T I O N S. 1. A telephone system employing searcher-selector circuits combined to be associated with a central office operator position for the purpose of establishing long-distance communications, in which the searcher is under the control of a switching operation. performed by the operator to make it work either with automatic selection of the calling line or with automatic selection of an automatic switch having access to a line terminating at the line of the remote office, the selector of the junction circuit in both case being controlled by the operator to route the communication through an outgoing line terminating at another remote office. 2. A telephone system employing operators at the central office for the establishment of long-distance communications in which the operators can establish one of the two types of communication, excluding the others, relating to long-distance communications. gues distances emitted by the local automatic offices or relating to long-distance communications emitted by the local manuals, the changes of circuits necessary in the equipment of the operator position to handle the two types of communication being carried out by the operation of a key by the operator. 3. A telephone system employing searcher-selector circuits combined to be associated with an operator position of the central office in which the operator positions are of two types the searchers of the junction circuits associated with the positions of one of the types having <Desc / Clms Page number 154> access to lines leading to remote offices and researchers associated with positions of the other type having access to local offices while the selectors of all trunk circuits have access to lines going to both remote offices and local offices. 4. A telephone system employing combined transceivers to transmit the working position command pulses of a set of switches according to the digits retained by the recorder, in which if one of the switches is combined to perform an extended automatic selection, the transmission of transmitter pulses is automatically delayed until the completion of the given automatic selection by the return of a signal to the transmitter-recorder by another conductor than those employed for conversation. 5. The use in telephone systems of a transceiver-recorder controlled by an operator's position and having the capacity to record a determined number of digits in which the digits of the requested number are successively stored in the recorder. and are successively retransmitted as soon as the first recorder has been activated, the recorders releasing after the stored digits have retransmitted, whence it follows and if the number of digits to be stored to be retransmitted is greater than the number recorders available, the excess digits are stored successively on the released recorders. 6. A telephone system as claimed in claim 1 ,. 2 or 3 in which the functioning of the finder is <Desc / Clms Page number 155> controlled by a distributor and that if the distributor fails, the searcher is combined to be able to be controlled by the operator. 7. A telephone system as claimed in claim 6 in which a researcher starting circuit is normally closed by the distributor to make it work, but if the distributor fails, the starting circuit is restored by the operation of a key by the operator. 8. A telephone system as claimed in claim 1 in which the finder aims to make an automatic selection of an automatic switch for long distance communications from the local manual office. 9. A telephone system as claimed in claim 2 in which communications are established by the operators by means of combined seeker-selector circuits to be associated with the equipment of an operator position by the operation of a key. . 10. A telephone system as claimed in claim 8 or 9, in which during a long distance call from a local manual office communication is established to the central office by an operator A of the manual office and when the operator of the central office has obtained details of the desired communication communication is established by the researcher and the operator B from the manual office to the calling subscriber. 11. A telephone system as claimed in claim 10 wherein when the communication through operator B position has been established, communication through operator A position is released. <Desc / Clms Page number 156> 12. A telephone system as claimed in claim 10 in which communication to the called party is established by the selector of the seeker-selector circuit. 13. A telephone system as claimed in claim 1 in which the switching operations consist in the operation of a key. 14. A telephone system as claimed in claim 2 or 13, in which the operation of the key prevents the searcher from making the automatic selection of the calling line on the benches and when the circuit is associated with an operator position allows the searcher broom to move. automatically raise up to a determined level to make the automatic selection of a free automatic switch accessible by this level. 15. A telephone system as claimed in claim 10 wherein since communication through operator position A is still established when communication through operator position B is established and thus the calling party's line will be tested as "busy", the operator trice B receives a characteristic signal to indicate that it is connected to the line without this line being tested. 16. A telephone system as claimed in claim 15 wherein the characteristic signal is the intermittent operation of a signal lamp. 17. A telephone system as claimed in claim 16 in which, for a normal call, the lamp lights up continuously to warn the operator of the manual that she must test the line. <Desc / Clms Page number 157> 18. A telephone system as claimed in claim 10 in which the called number is manifested at operator B position by means of a call indicating device. 19. A telephone system as claimed in claim 10 in which the automatic call of the line by the equipment of the operator position B ceases under the control of the operator at the central office. 20. A telephone system as claimed in claim 3 in which provisions are made whereby an incoming call is transferred from an operator of one type to an operator of another type. 21. A telephone system as claimed in claim 20 wherein upon receipt of a call to be transferred the operator establishes a communication through a circuit which gives the seeker access to trunk circuits associated with the other operator. 22. A telephone system as claimed in claim 21 in which the communication is established by a selector operating under the control of the first operator. 23. A telephone system as claimed in claim 21 or 22 in which the communication established between the two subscribers passes through the seeker-selector circuits of each operator position. 24. A telephone system as claimed in claim 20 in which the possibility of transferring calls is provided and where one of the operators answers the incoming calls coming from the remote office, another establishing the calls to this remote office. 25. A telephone system as claimed in claim 24 in which if the called party of the remote office is not <Desc / Clms Page number 158> not accessible, a message is left for him asking him to get in touch with the operator who, when the call is received, will transfer him to the operator who had established the first call. 26. A telephone system as claimed in claim 4 in which the delay is applied only for switches having automatic level selection capabilities. 27. A transceiver as claimed in claim 5 in which if the transceiver catches up the digits stored by the loggers, the next operation of the transceiver is delayed until another digit is registered. 28. A transceiver as claimed in claim 5 in which storage of digits on freed loggers continues uninterrupted after the digit is logged on the last logger. 29. A recording transmitter as claimed in claim 5 in which the recording transmitter is automatically associated with the operator position by a trunk circuit when the attendant answers a call and is disconnected from it by the maneuver. with a key when all the digits have been stored. 30. A recording transmitter as claimed in claim 5 in which a group of count relays placed in the transmitter is used to determine the time interval between the transmission of pulses of two consecutive digits, the number of relays being capable of being. easily modified to vary the length of this interval. <Desc / Clms Page number 159> 31. A telephone system as claimed in claim 1, 2 or 3 in which a supervisory lamp is provided in each circuit to give a visual indication of the progress of the call and is illuminated to remind the operator. 32. A telephone system as claimed in claim 31 in which the supervisory lamp circuit is controlled by a relay which is kept attracted during the duration of the call and which releases, to ignite the lamp when the call is on. operator is called back. 33. A telephone system as claimed in claim 32 in which a momentary signal is transmitted on the junction .circuit to cause the release of the relay which remains de-energized until the operator answers. 34. A telephone system as claimed in claim 33 in which for a communication established over a line terminating at the remote office, the signal consists of an AC pulse transmitted over the trunk line and for an established communication. from a local office the signal consists of the reversal of the battery connections against the talk leads. 5. A telephone system as claimed in claim 34 wherein the AC pulse causes a relay to operate in a line circuit to bypass the supervisory relay circuit. 36. A telephone system as claimed in claim 34 in which reversal of the battery connections causes a relay to operate to introduce a resistance in the supervisory relay circuit of a value such as the supervisory relay <Desc / Clms Page number 160> released. 37. A telephone system as claimed in claim 1, 2 or 3 in which if a line which terminates at the remote office becomes defective, an operator who seizes this line by a junction circuit orders by one of the conversation conductors the application of a special tone on the line . 38. A telephone system as claimed in claim 37 in which a relay in the line circuit associated with the defective line is actuated following a momentary switching maneuver by the operator and controls the application of a tone on the line and also keeps the line against any further seizure. 39. A telephone system as claimed in claim 38 in which the relay is blocked in series with the lamp placed at the test panel. 40. A telephone system as claimed in claim 39 in which when the line is repaired the blocking circuit is opened by the operation of a key at the test panel and the line circuit restored to its normal position. 41. A telephone system as described herein and shown on the attached plans.