BE482797A - - Google Patents

Description

       

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  "Automatic telephony system with gluing means for a" commuta.tion "train.



   The present invention relates generally to telephony systems and, more particularly, to automatic telephony systems using researchers to connect calling lines to digital or controlled switches.



   The invention aims to establish, in a telephone system of this type, new and novel circuits for making the various telephone connections.



   The invention further aims to establish, in a telephony system of the type indicated, a porfected switching train comprising new and novel means for enabling a called subscriber to prevent a calling subscriber from releasing the switching train, as well as to allow the called subscriber to send a signal to the agent of the office or central to ask him to search for the calling line from which the call originated.

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   The invention further aims to establish an improved finder for use in a communication between two subscriber lines, this finder, when so used, can be released by a long distance operator in a novel way. unprecedented, this before this operator forwards a long distance communication to the calling subscriber line of the previously established subscriber communication, without inviting the calling subscriber to disconnect first.



   The invention further aims to establish a new and efficient switching selector intended for an exchange, this selector becoming an intermediate selector in the switching train after a call initiated in the exchange has been identified as being intended for another line. subscriber belonging to the same exchange, and in such a way that this switching selector repeats the pulses to intermediate and final switches in a corresponding exchange after a call initiated in the aforementioned first exchange has been identified as being intended for an exchange. subscriber line of the corresponding exchange.



   The invention further aims to provide a switching selector capable of "going on" or "forwarding" directly and automatically after the first digit of a number has been formed, but which can "absorb" both or first three digits of a dialed number and then automatically "forward" after the third or fourth digit, depending on the circumstances.



   The invention further relates to a switching selector which incorporates a junction finder in a new and novel way to connect this selector with a free outgoing junction circuit, as soon as this selector is entered.



   The invention further aims to establish new and improved means for rendering "obsolete" or "prescribing" a call.

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 initiated in an exchange equipped with switching selectors, in the event that the calling station fails to dial within a determined period of time with, as a result, an automatic release of the outgoing junction circuit which had been occupied by the switching selector following the initiation of the call.



   The invention also aims to establish an outgoing junction circuit comprising improved and novel means for causing the release of the associated incoming selector provided in the corresponding exchange.



   A feature of the invention is the arrangement whereby a busy guard potential is applied to the special test or test (EC) bench contacts of connectors directly from the private exchange line circuits ( PBX) served by these connectors, with the exception of the last line of each group of private exchange lines, in order to cause these connectors to automatically scan by rotation the busy lines of the group of lines of the private exchange up to whether a free line is chosen in the group or the last line of the group is reached.



   Another feature of the invention relates to the use of a combination of a bed and a vertical wiper, a set of right-hand shaft springs and a set of springs or shaft contacts. left in the switch selector so that the latter is caused to drop and "absorb" certain digits of the number dialed before forwarding the communication to the following switches.



   Another characteristic of the invention relating to the switching selector resides in the fact that, when a call is initiated by means of this selector and the calling party does not start dialing within a determined period of time, the call selector switching is not released

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 as a result of the "prescription" and the resulting disconnection of the outgoing junction circuit busy, but remains [} available to the calling station in the event that the latter subsequently dials a local number with respect to the exchange in which this selector is installed.



   Another feature of the invention relates to an improved monitoring device of the outgoing junction circuit, in which a lamp illuminates with full voltage to indicate that a switching selector has entered the outgoing junction circuit, remains fully. illuminated for the duration of the occupation of this circuit, but is reduced to a faint glow when the switching selector is released, thus providing an indication that this release has taken place and that the associated incoming selector provided at the corresponding exchange has not yet returned to its normal position, this lamp extinguishing when the incoming selector is released, indicating that the outgoing trunk circuit is ready to be used for a new call.



   The invention has yet other objects and characteristics, most of which relate to the details of the circuit necessary to implement these objects and characteristics.



   The various objects and characteristics of the invention will be better understood on reading the following description relating to the accompanying drawings comprising FIGS. from 1-A to 16 inclusive and which represent, using the usual circuit diagrams, a part of the apparatus sufficiently extensive to allow the description and understanding of the invention.



   Fig. 1-A shows a subscriber line of the individual type multiple connected to the respective sets of lower bank contacts of a group of line seekers, one of the researchers of the group being shown in fig. 2.



   Fig. 1-B shows a subscriber line of the "private office" type

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   (PBX), which can be multiple connected to the respective sets of lower bank contacts of the line hunters group in a manner analogous to that shown for the individual subscriber line.



   Fig. 1-C shows a subscriber line (not detailed), which can be either of the individual type according to fig. 1-A, or of the “private exchange” or “shared line” type according to fig. 1-B, this line being connected in multiple to the respective sets of upper bank contacts of the line finder group.



   Fig. 2 shows the layout of the circuit of a line finder with sets of trotters for lower and upper stud banks and with a vertical wiper.



   Fig. 3 shows a distributor who assigns free line seekers of a group in order to search for calling lines among the subscriber lines connected to the sets of contacts or bench pads of the group of line seekers.



   Fig. 4-A shows a group of control relays common to. a group of line seekers, and the associated distributor.



   Fig. 4-B shows a group of control relays common to another group of line seekers, and to the associated distributor.



   Fig. 5 shows a first local selector which combines with a line finder (Fig. 2) to form a line finder-selector junction.



   Fig. 6 shows a circuit of an intermediate selector whose banks are connected to connectors or intermediate selectors.



   Fig. 7 shows an individual line connector used to extend connections to individual type subscriber lines (Fig. 1-A).



   Fig. 8 shows the employee private office type connector

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 to extend connections to private office lines (fig. 1-B).



   Fig. 9 shows the elements and details of the. trunk operator equipment circuit which directly relates to the present invention, all other circuit elements and details of conventional trunk operator equipment being omitted for simplicity of the drawings.



   Fig. 10 shows an outgoing selector used to choose an outgoing junction circuit associated with an incoming selector, in a corresponding office or central. The outgoing junction circuit is shown in fig. 10 by a rectangle, the details of this circuit being the same as those shown in fig 13.



   Figs. 11 and 12 show the components and wiring of a switching selector, fig. 12 also comprising the outgoing junction finder associated directly with this selector. The switching selector in figs. 11 and 12 is combined with a line finder (fig. 2) to form a switch finder-selector junction. The vertical bench wiring of the switching selector according to fig. 11 allows the latter to "enter the game" or "intervene" immediately after the dialing of the third digit, when this third digit of the call number is 1.



   Fig. 13 shows the circuit details of the outgoing junction which is accessible to the outgoing junction finder
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 (fi [,. 12) of the switching finder or secondary outgoing ¯préséleotetlT (fig. 10).



     IL ::. 14 shows an outgoing selector installed in a central terminal and directly associated with a ring circuit.
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 -Outgoing lion (fig. 15) instilled in the original central â-, e.



  Fig. 15 shows the oLTcl.it of the vertical bench of 861 ('0 c8l1r de OOil! LYfute, ticn, n60essairo in order to bring this selector to intervene immediately after dialing the fourth digit of a subscriber number , when the third

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 digit is 6, or to intervene immediately after the coin- position of the first digit when it is 9.



   Fig. 16 is a diagram reduced to its simplest form and showing the method by which the long distance operator "forwards" and "breaks" a call between two local subscribers.



   Fig. 17 shows a numbering plan with a view to assembling the drawing sheets so as to establish a continuous drawing of the circuit according to the invention.



   According to figs. 1-A, 1-B and 11, a subscriber station is associated with each of the subscriber lines of the telephone system, the subscriber stations A (fig. 1-A), B (fig. 1-B ) and C (FIG. 11) being associated respectively with the subscriber lines 100, 100 'and 1107. Each of the subscriber stations is provided with a telephone apparatus, a dialing mechanism and a ringing tone. Each subscriber line has a line relay and a cutoff relay, these relays being indicated respectively by 110 and 120 in line 100 and by 110 'and 120' in line 100 '.

   In addition, an overvoltage counter (not shown) is associated with each subscriber line, the counter associated with the line 100 being connected to the armature 111 of the line relay 110, and the counter associated with. line 100 '- to armature lll' of line relay 110 '. Line 100 represents the type of an individual or unshared subscriber line, while line 100 'represents the type of a private exchange line or shared line. The general differences between the two types of lines are that the line relay 110 'is equipped with an additional armature 114 and an associated working contact, and that the armature 122 of the cutting relay 120' is provided with a working contact as well as of a rest contact.

   The subscriber line 1107 is not shown in detail, but can obviously be either type 100 or type 100 '.

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   The subscriber lines are arranged by first and second groups of 100 lines each, a first group and a second group forming a group of 200 lines. Each group of 200 lines is accessible either to a first and a second group of local searcher-first selector junctions, or to a first and a second group of switching searcher-selector junctions, depending on the type of exchange.



  For example, a main office is equipped with researcher-first local selector junctions (figs. 2 and 5), while a satellite office (branch office) is equipped with researcher-switching selector junctions (figs. 2, 11 and 12). ), each group of trunks being equipped with a common distributor (fig. 3) to assign the free trunks to the calling subscriber lines.

   Each first group of lines relates to a first distributor, while the corresponding second group of lines relates to the corresponding second distributor, so that the calling lines of the first group are normally assigned free trunks. among the first group of corresponding trunks, while the calling lines of the second group of lines are assigned free trunks among the second group of corresponding trunks.

     On the other hand, the first and second distributors are arranged and connected in such a way that a call initiated on a line of the first group is assigned a free junction of the corresponding second group, in the case where all the junctions of the first group would be busy, while a call initiated on a line in the second group is assigned a free trunk in the first group in the event that all the trunks in the second group are busy. The lines of the first group of lines terminate at the first five levels or floors of the first group of line seekers, and the lines of the second group, at the second set of five levels of the first group of researchers.

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 line.

   Conversely, the lines of the first group lead to the second set of five levels of the second group of line seekers, and the lines of the second group to the first set of five levels of the second group of line seekers.



  Then, the contacts or pins n 2 to n 9 inclusive of the vertical banks 250 of the first group of researchers are multiple in reverse order to the contacts n 2 to n 9 inclusive of the vertical banks of the second group of researchers, as shown in figs. . 2 and 4-A. This multiplication of the vertical banks of the two groups of researchers has the effect that pins 5 of banks 250 correspond to pins 6 of banks 250 'and that pins 6 of banks 250 correspond to pins 5 of banks 250', etc. ..



   A group of control relays, such as the group of relays according to fig. 4-A, to control the operation of the junctions and the distributor.



  The relay group consists of a start relay 445, a busy transfer relay 440, a step relay 415, a transfer relay 430, a first group test relay
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 465, a second group test relay 460, 1'819.: 1 duration count 420, 405 and 4-10, a monitoring alarm relay 400, control relays 425, 250 and 470 , and 1.th transfer correction key comprising two. studs 403 and 404.



     Each distributor is arranged and connected in a manner analogous to that of FIG. 3, or this distributor comprises two banks of fixed pins and two trotters associated individually with each of these banks, the corresponding pins of each bank the test or control wires going
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 sux jii> c.li <, t> c respective group, L;

  hn ''! is that lc frct'-urs t "rmindnt test leads going to group (1 <; rel: i (1 floi, i:, #.> .: àr # From aubre part, the distributor <; v,; ii = .rem: 1¯ an elcutro 300 to drive in rotation the rubbers r'.sociés 1:,. 1;., i spindle banks or stud;]. From the mechanical point of view, the G. i, B .l; =: 1 1>; ; -1; <; u.i; .s

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 are analogous to the known step-by-step rotary preselectors which do not have a normal or rest position, but whose circuits have been modified in accordance with the present invention.

   Each distributor is of the pre-assigned type in this sense that a free trunk of the respective trunk group is assigned to a calling line of this group prior to the initiation of a call on a line of this group, another free trunk of the group in question being automatically assigned to the next calling line of the group as soon as the. first assigned trunk works to find the calling line.



   Each finderscope (Fig. 2) includes the well-known 600-point Strowger switch mechanism capable of upward and downward movement and has, in addition to the usual switch rubbers, a shaft trotter 253 exploring a bank of spindles. vertical 250 individual switch. Associated with the Stroviger mechanism are: a set of switching springs 214 actuated by the vertical movement of the switch shaft from its normal position; a set of switching springs 219 actuated by the rotational movement of the switch shaft after this shaft has been lifted up; and, a set of switching springs 237 actuated by movement of the shaft to its eleventh rotary position.

   Each seeker further includes a start relay 200, two switching relays 220 and 230, and accesses a first group of 100 subscriber lines and a second group of 100 subscriber lines.



   Each first local selector (Fig. 5) includes the known 300-point up-and-turn Strowger switch mechanism. To this mechanism is associated a set of switching springs 524 actuated by the vertical displacement of the switch shaft from its normal position, and a set of switching springs 507 actuated.

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 by moving this shaft to its eleventh rotary or horizontal position.

   Each first local selector further comprises a combined line and transmission supply relay 500, capacitors 504 and 505 in the voice transmission circuit, a stick relay 510, a communications count relay 520, a step relay 530, it transfer relay 540, a switching relay 550, a supervisory lamp 533 and an occupancy key 519, and accesses ten groups of ten junctions each.



   The switching selector according to figs. 11 and 12 include the known 300-point Strowger switch mechanism, with vertical and horizontal movements, and in addition to the usual wipers is provided with a shaft slider 1139 exploring an individual vertical pin bank 1138 of the switch. Associated with this Strowger mechanism are two sets of switching springs 1147 and 1148 called the right and left shaft spring sets respectively. Spring set 1147 operates when the switch shaft is lifted to a determined bank level, following the formation of the first digit, in order to bring about an automatic return of the shaft and the wipers of the switch. switch to their normal positions.

   Spring set 1148 works when the switch shaft is lifted to a bench level determined as a result of forming the second digit, also for the purpose of bringing about the automatic return of the shaft and friction. switch to their normal position. The Strowger mechanism further comprises a set of switching springs 1245 actuated by the vertical movement of the switch shaft from its normal position, and a set of switching springs 1225 actuated by the movement of this shaft towards its normal position. eleventh rotary position.

   Like the first local selector, the switching selector has a combined line and transmission power relay, condensers.

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 sators in the voice transmission circuit, control relays, a supervision lamp and an occupancy key.



  The switching selector accesses through its sliders ten groups of ten junctions each.



   An outgoing junction finder (fig. 12) of the known type with a step-by-step rotary preselector is directly associated and permanently connected to each switching selector. The outgoing junction finder comprises three banks of fixed pins and three wipers associated with them individually, the corresponding pins of each bank terminating the conductors of an outgoing junction circuit (fig. 13) while the trotters terminate the conductors of the switch selector. switching. On the other hand, the outgoing junction finder includes an electro 1270 for driving in the horizontal direction the wipers associated with the banks of pins.



   The intermediate selectors, shown clearly in figure 6, each comprise a switch mechanism of the known Strowger type and are arranged in a similar manner to that of the first local selectors described above. Here, however, each intermediate selector comprises a line relay 600, a transfer relay 620, a combined switch and stick relay 630 and a relay 610, instead of the relays indicated for the first local selector; on the other hand, the voice transmission circuit does not include a capacitor.



   The individual line connector according to fig. 7 comprises the known Strewger switch mechanism with 300 points and with an ascending and rotating movement. With this mechanism is associated a set of switching springs 766 actuated by the vertical movement of the shaft from its normal position, a set of switching springs. 771 actuated by the rotational movement of the switch shaft after this shaft has been lifted by the ascent, and a number of control relays.



  The connector accesses a group of 100 individual subscriber lines.

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   The "private office" or "shared line" connector according to fig. 8 features the well-known 400-point Strowger switch mechanism and special vertical and rotary motion control bench. Associated with this mechanism is a set of switching springs 866 actuated by the vertical movement of the switch shaft from its normal position, a set of switching springs 871 actuated by the horizontal or rotational movement of the switch shaft. after this tree has been raised by ascent, and a number of control relays. The shared line connector accesses 100 shared lines or a combination of shared lines and individual subscriber lines, not exceeding a total of 100 lines.



   The outgoing junction circuit (fig. 13) consists essentially of a group of control relays and a transformer. The latter serves to provide a high potential which is momentarily applied to. a conductor of the transmission circuit to achieve a release condition in the manner described in the chapter "Calls from the Satellite Office (Branch Office) to the Main Office".



   Each first incoming selector (fig. 14) is permanently connected to an outgoing junction circuit (fig. 13) and features the known 300-point Strowger mechanism with vertical and rotary motion. With this mechanism is associated a set of switching springs 1425 actuated by the vertical movement of the switch shaft from its normal position, a spring set 1405 actuated by the rotary movement of the switch shaft after this shaft has been lifted by the ascent, and a set of switching springs 1445 actuated by the displacement of said shaft towards its eleventh position, as well as a number of control relays. The first inbound selector accesses ten groups of ten trunks each.

   The outgoing junction circuit distributor according to fig, 10

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 is from l;, J'J) 8 known to hreselect rotary not to. not and comprises three banks of fixed pins and three wipers associated therewith individually, the corresponding pins of each bank terminating the conductors of an outgoing junction circuit similar to that of FIG. 13, while the wipers terminate conductors coming from the multiple banks of the local selector switches or selector switches. In addition, the outgoing junction circuit distributor includes control relays and an electro 1030 for the rotary drive of the wipers associated with the spindle banks.



   It should be noted here that, although the embodiment of the present invention set forth in this description includes the known switches whose banks have determined capacities, this invention is not limited to. this embodiment, but can use switches with banks having other capacities, or other combinations of the switches. It should also be noted that the capacitors provided in the voice current transmission circuits are bypassed by resistors of high values so that battery potentials are applied to "dry" contacts in the voice transmission circuits for the purpose of ensure "silent" voice current transmission circuits.



   In addition, and although the drawings show several battery connections for the switches installed in any one of the exchanges, it should be noted that they preferably relate to the same battery for the exchange considered. In addition, and in order to further simplify the drawings, known accessories such as occupancy keys, jacks to allow an attendant to plug in the various switches, spark arrester devices, monitoring and signaling devices have been omitted. release, duration counters, buzzer and buzzer generators,

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 and the like.

   Buzzer and Buzzer Generators provide known items such as continuous inrush current, interrupted inrush current, generator grounded, switching signal and busy signal.



   After having described the equipment and apparatus, a detailed description of the operation will be given below.



   Post calls coming from the Main Office to Individual Post Lines coming from the Main Office.



   Main office extension calls to individual main office extension lines are set up as will be briefly described below:
The person present at the calling station removes the handset from the fork and, after hearing the usual maneuver signal, dials the number of the desired station. If the latter is busy, the calling party receives a busy signal. If the extension called is not busy, an automatic ringing is heard intermittently.



   Release of the call is normally subject to the will of the caller.



   To describe such a local call in detail, it will be assumed that station A (fig. 1-A) initiates a call to another station belonging to the same exchange. It will also be assumed that the finder shown in fig. 2 has been previously assigned by the relevant distributor (fig. 3). The occupancy transfer relay 440 of the relay group of FIG. 4-A is normally kept attracted by the free researchers of the first group, for example on the circuit: earth, armature 236 and its rest contact (fig. 2), armature 211 and its rest contact, armature spring 216 and its rest pad, conductor 493, armatures 409 and 408 (fig. 4-A), coil of relay 440, battery.

   Removing the handset from the fork at station A closes a circuit to energize line relay 110, as follows: earth, armature 122, current loop

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 continuous in the telephone of set A, armature 121, coil of line relay 110, battery. At armature 112, relay 110 indicates to the benches of the group of researchers having access to the group of lines in which the line circuit of station A is located, that the latter is calling, by connecting the battery by the winding of the cut-off relay 120 and conductor 133 to bank C pins or pads (test) of the line circuit of station A. To the armature 111 and its working pad, the relay 110 connects the earth to the test conductor going to the bench terminals of the connector of the station A ,, to indicate to the connectors having access to this station that it is occupied.

   To the armature 113, the relay 110 applies an earth potential to the starting conductor 115 connected to the pin or pad n 1 of the vertical bench 250 of the researcher assigned in advance according to fig. 2, as well as at pin 1 of the multiplied vertical benches of all researchers of the same group.



   The earth potential connected to pin n 1 of the vertical bench 250 passes through the resistor 251, the conductor 480, the armature 441 and its working pin, the winding of the starter relay 445 from the group of relays to the battery, energizing thus relay 445. At armature 4q6, relay 445 closes an obvious circuit for the duration count relay 420; and, on the armature 437 and its rest pad, the circuit: armature 447, coil of relay 450, conductor 490, interrupt armature 301 (fig. 3), coil of electro 300, battery, circuit which does not is used only to energize relay 450, the high resistance of the latter preventing the energization of the electro 300.

   Also, at frame 447, relay 445 sends. an earth potential of the armature 437 and its resting pad at pin 5 of the vertical bench 250 by the armature 442, the conductor 472, the armature 464 '(fig. 4-B), the conductor 478,

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 the pin 6 of the vertical bench 250 'and the multiplication between the pin 6 of the bench 250' and the bench 250 in order to prevent the researcher (fig. 2) from exploring higher than the fifth level or floor of his benches .



   At armature 453, relay 450 closes @ circuit for the start relay 200 of the searcher junction assigned to advance-selector by: earth, armature 453, conductor 484, searcher distributor wiper 305, distributor bench pin , conductor 495, winding of relay 200 of the researcher, battery, from where energization of relay 200.

   At armature 457, relay 450 closes a multiple circuit for occupancy transfer relay 440; at armature 454, it closes an excitation circuit of step-by-step relay 415, as follows: earth, interrupting armature 240 (fig. 2), interrupting armature 241, armature 205, conductor 485, armature 454 (fig. 4-.A), armature 435 and its resting pin, lower winding of the stepping relay 415, battery; at armature 452, it forms a circuit for energizing test relays 460 and 465, as follows: earth, armature 452, upper coil of relay 460, lower coil of relay 465, resistor 467, battery; and, at armature 451, it closes a multiplied circuit for the duration count relay 420 as follows:

   armatures 446, 451, coil of relay 420, battery.



   The line finder start relay 200 closes to the armature 201 a loop circuit comprising a resistor 215, for the line relay 500 (fig. 5) of the other first local selector, which causes the relay 500 attracting and closing an obvious circuit to bond the relay 510. To the armature 513, the bonding relay 510 connects the earth potential to the conductor 272 through the occupant key 519 for a purpose which will be described below.



   At armature 429, the duration count relay 420 connects a multiplied earth to relay 450 and to pin 5 of the bank

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 vertical 250; and, to the armature 421, connects the earth potential to the conductor 417 of the transfer counter 438, the operation of which will be explained in a later paragraph of this chapter.



   The operation of the step-by-step relay 415 has the effect of closing an excitation circuit of the ascension electro 240 of the researcher, as follows: earth, armatures 428, 416, 427, armature 436 and its rest pad, conductor 489, armature 209 (fig. 2), electro 240 winding, battery. While operating, the electro 240 raises the seeker's shaft and friction sets one step and cuts the circuit from relay 415 to interrupt armature 241 so that this relay drops out.

   Raising the finder shaft by one step activates the ascension shaft contact 214 and the vertical friction selector 253 contacts the # 1 spindle of the vertical bench 250, thus closing a circuit. 'energization of relay 425 as follows: earth, contact 113 (fig. 1-A), conductor 115, pin n 1 of bank 250, trotter 253, armature conductor 115, pin n 1 of bank 250, trotter 253, armature 202, conductor 481, armature 432 (fig. 4-A), upper winding of relay 425, battery, On pulling, relay 425 is blocked in the following circuit: earth, armature 452, armature 434 and its rest contact, winding lower transfer relay 430, armature 426, lower coil relay 425, battery;

   and, At armature 427, cuts the circuit of the ascension electro 240 so that this electro releases and closes the circuit of the relay 415 at the interrupt armature 241. The stepping relay 415 attracts again. .



   Closing the blocking circuit of relay 425 as described in the previous paragraph also causes the transfer relay 430 to be energized, which blocks a circuit evident for its upper winding by armature 433. At armatures 432 and 434, relay 430 cuts the circuits of the soft windings

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 relay 425, which drops out; at the armature 434, the relay 430 closes a bonding circuit for its upper winding independently of the armature 452, as follows: earth, armature 428, armature 434 and its working pin, armature 433, upper winding of. relay 430, battery;

   at armature 436, relay 430 transfers the ascension electro 240 pulse circuit from the seeker to the spin electro 245; at armature 435, it transfers the circuit of cut-off armature 246 of electro 245 from the lower winding of relay 415 to the upper winding of this relay; to armature 437, it connects the earth potential to the counter by tests 438;

   and, to the armature 431, connects an earth multiplied by the armature 451 to the winding of the duration counting relay 420. The step-by-step relay 415 is provided with two coils, a transfer between these coils being carried out according to whether the ascending electro 240 or the rotating electro 245 must receive pulses, since when operating through its lower winding, relay 415 provides a very efficient pulse circuit for the ascending electro 240 , while, when operated by its upper winding, this relay provides an equally efficient pulse circuit for the 245 rotation electro.

   Releasing relay 425 closes the pulse circuit of electro 245 as follows: earth, armatures 428, 416, 427, armature 436 and its working pin, armature 461 and its resting pin, armature 466 and its rest, conductor 488, armature 208 (fig. 2), armatures 225, 235, winding of the rotary electric 245, battery. The researcher is now in the process of exploring, using his wipers 260, 261, 262, 263, 264, 265, the first level or stage of the banks of studs or pins of the subscriber lines.



   The electro 245 operates and moves the shaft and the wiper sets in a horizontal step on the first level of the stud blocks, the rotation shaft contacts 219 being

  <Desc / Clms Page number 20>

 actuated during this step. At the cut-off or interrupting armature 246, the electro 245 interrupts the circuit of the relay 415, thus causing the latter to drop and cut the pulse circuit from the electro 245 to the armature 416. Electro 245 drops out and closes the circuit from relay 415 to the disconnecting armature 246. Relay 415 attracts again and closes the impulse circuit of electro 245. Electro 245 again operates, drives the shaft and the seeker rubbers of a second horizontal step and again cuts the circuit of relay 415.

   This reciprocal action between the electric 245 and the relay 415 continues until one of the subscriber line rubbers contacts a bank pad marked by a calling line. Assuming that the calling line has marked a bench pad which has been reached by the control or test wiper 265, the winding of the cut-off relay 120 (fig. 1-A) will be connected to the test wiper 265 by l the armature 112 of the line relay 110 and the aforementioned bench stud, so that the wiper 265 closes the circuit of the test relay 465 (fig. 4-A) as follows:

   - earth, armature 423, rectifier 458, upper coil of relay 465, conductor 482, armature 203 (fig. 2), trotter 265, bench stud connected to trotter 265, conductor 133, armature 112 (fig. 1-A), winding of the relay 120 of the calling station, battery, thus energizing the relays 120 and 465. The relay 120 connects its winding to the Frotor 265 by the armature 123 and, to the armatures 121 and 122, releases it. line of fasteners. So line relay 110 drops out. At the armature 111 and its rest pad, the relay 110 sends the earth potential through the wiper 265 to the test lead C of the bench multiplication of the connector and to the communications meter wire of the subscriber line; and, at the armature 113, disconnects the earth of the conductor 115 and of the stud n 1 of the bank 250.

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   Test relay 465 cuts off the electro 246 pulse circuit at armature 466 to prevent subsequent horizontal displacement. Relay 465 operates with extreme rapidity with regard to stopping wiper 265 on a bench pad marked with a subscriber line, thanks to the fact that this relay has been pre-energized in its lower winding by the operation of the retort relay 450 indicated in a previous paragraph.

   At armature 466, relay 465 closes a circuit of switching relay 220, as follows: earth, armatures 428, 416, 427, armature 436 and its working pin, armature 461 and its resting pin, armature 466 and its work stud, conductor 487, armature 207 (fig. 2), armature 234, lower coil of relay 220, battery, thus causing relay 220 to attract and lock in a circuit as follows: earth, armature 513, (fig. 5), occupancy key 519, conductor 272, armature 223 (: fig. 2), upper coil of relay 220, trotter 265, bench stud connected to the slider 265, conductor 133, armature 123 (fig. . 1-A), coil of relay 120, battery.



  The relay 120 is also retained in the working position by the blocking circuit which has just been described. To armatures 221 and 222, relay 220 extends the call loop of station A through line relay 500 of the first local selector, multiplying with the loop through resistor 215 and armature 201; and, at. the frame 226, connects the earth potential to the trotter 306 of the searcher distributor for a purpose which will be described later.



   The control circuit of the lower coil of the switching relay 220 is controlled through the armature 416 of the stepping relay 415, the operation of which is in turn controlled by the closing of the cut-off armature contact 246 of the electro. rotation 245, to ensure that an operation
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 d, the establishment of connection "of relay 220 can only take place after the rotation electro 245 is completely

  <Desc / Clms Page number 22>

 released.

   In the event that the searcher slider 265 passes over a subscriber line bench pad as a metering overvoltage is applied to that pad to actuate the communications meter associated with the subscriber line, the high resistance that opposing rectifier 458 to a current in this direction would prevent improper operation of test relay 465.



  We will temporarily depart from the description of the local call to explain the method of automatically assigning seeker-selector junctions to successive calls from local stations. It has been said above that releasing line relay 110 has the effect of removing the earth potential of wire 115 and of pin # 1 of the vertical bench '250 of the finder. This removal cuts the circuit to start relay 445, on condition that no other call has been initiated in the subscriber line group, with release of relay 445.

   This release removes a multiplied earth from the coil of the duration counter relay 420 and, at armature 449, removes the earth potential of the conductor 462 going to a delayed alarm circuit (not shown).



   The earth potential connected to the contactor 306 of the distributor by the armature 226 short-circuits the coil of the relay 450 to the armature 456 and its working contact, the relay 450 drops out. At armature 451, this relay cuts the circuit of relay 420; at armature 452, it cuts the circuit of the upper coil of relay 460 and of the lower coil of relay 465; at armature 453, it cuts the circuit of relay 200 of the finder; and, at armature 454, breaks the circuit of relay 415.



  The short-circuiting of the relay 450 allows the electro 300 of the distributor to operate and to place its pawl in a position preparatory to driving the wipers 305 and 306 by one step. Releasing relay 420 cuts the circuit from the upper coil of relay 465 to armature 423, causing relay 465 to drop; at frame 421, it removes the earth

  <Desc / Clms Page number 23>

 the conductor 417 of the duration counter 438; and, at the armature 428 cuts the blocking circuit of the relay 430. The release of the relay 200 of the researcher has the effect of connecting a multiplied earth to the contactor 306 of the distributor to the armature 210; and, at armature 201, eliminates the bypassing of conductors 270 and 271 by the loop of resistor 215, thereby placing line relay 500 of the first local selector under the control of calling station A.

   Releasing relay 430 removes the earth potential of the test meter 438 to the armature 437.



   The operation of the solenoid 300 of the distributor opens the breaking pads 301, thus causing the release of the electro 300, so that it advances the wipers 305 and 306 by one step. In the event that the next seeker-selector junction is already entered, the friction device 306 would find the earth potential on the bench stud of this junction, which potential would again actuate the electro 300 of the distributor, thus preparing the advancement of the rubbers 305 and 306 by a new step, and would short-circuit relay 450 again to prevent operation of the latter in the event that the start relay 445 were to operate following a call from another subscriber line, before the distributor has found a free seeker-selector junction.

   In the event that the second seeker-selector junction tested were also occupied, there would be an earth potential on the bank contact of this last junction and the electro 300 would be caused to advance the wipers 305 and 306 a new step. This series of steps and tests continues until trotter 306 reaches a bench stud of a free searcher-selector junction. When the distributor finds a free finder-selector junction, no earth potential is returned to actuate the electro 300, and the relay 450 can operate in the event that another call is on hold.

  <Desc / Clms Page number 24>

 



   To return to the description of the local call, the line relay 500 of the first selector is now stuck by the calling loop of station A and the maneuver signal arrives at the caller via the rest pad of the spring el 'a.r1Da. ture 517 of the ascension shaft contacts 524, the conductor 534, the lower coil of the relay 500, the conductor 271, the armature 222 (fig. 2), the trotter 263, and the associated "+" bench block at calling station A, on the conversation circuit of this station.



    Having received the well-known switch signal, the caller dials the number of the desired local extension. Following formation of the first digit, the circuit of the relay 500 of the first selector is interrupted a number of times equal to the number of pulses of the first digit. The relay 500 drops out momentarily at each pulse, and at armature 502 cuts off the circuit of the sticking relay 510. The latter being of the delayed release type, does not drop out during the pulse period. So the circuits controlled by this relay are not disturbed.

   At armature 502 and its rest pad, relay 500 transmits a pulse to 1 ascent electro 560 and to relay 540 on each de-excitation. This multiple circuit is established as follows: earth, armature 502 and its rest pad, armature 514 and its work pad, armature 555, electro coil 560, battery, as well as: armature 514 and its work pad, winding of the rela.is 540, battery.



  Relay 540 attracts and, since it is also unlatched differs, it does not drop out during the pulse period.



  The electro 560 attracts and releases with each de-energization and new energization of relay 500, thus raising the shaft and the rubbers of the first selector by a corresponding number of vertical steps. The ascension shaft contact 524 is actuated during the first vertical step, by disconnecting the operating signal at the resting pad of the armature spring 517 and by connecting the lower coil of the relay 500 to a

  <Desc / Clms Page number 25>

 direct earth @ through the armature spring 517 and its working stud.

   In addition, actuation of the ascension shaft contact 524 closes a circuit of the paspas 530 retort relay follows: earth, armature 515, armature 557 and its resting pin, armature spring 518, cut-off armature 566, winding relay 530, battery, causing so. the. traction of relay 530.



   Shortly after receiving the last pulse of the first digit, relay 540 drops out and closes the circuit of the rotation electro 565 as follows: earth, armature 543 and its rest pad, armature 531, coil of electro 565, drums.



  The electro 565 attracts and rotates the shaft and the rubbers of the first selector one step in the level determined by the ascent pulses. Operation of electro 565 also opens the circuit from relay 530 to disconnect armature 566, so that relay 530 drops out and interrupts the circuit from electro 565 to armature 531. Electro 565 releases at in turn and closes the circuit of relay 530. The operation of the first selector depends at this moment on whether the second selector connected to the first block of pads of the level chosen by the ascent pulses is occupied or free.



   If the second selector is free, the wiper 529 of the first selector finds a battery potential supplied by the second selector on the pin C of the first block of pads, and a circuit for the relay 550 of the first selector closes as follows: earth, armature 515, lower winding of relay 550, cut-off armature 526, trotter 529, bench pad C connected to slider 529, conductor 537, battery potential supplied by conductor 537 from the first selector, so that the relay 550 attracts, and prevents the arrival of subsequent rotational pulses at. first selector. At. case where the second selector is occupied, the wiper 529 of the first selector finds an earth potential on the pad C of the first

  <Desc / Clms Page number 26>

 block of studs, so that the relay 550 of the first selector cannot attract.

   The circuit of the relay 530 is therefore maintained at the armature 557 and its rest pad, which causes the relay 530 to attract again and to close the circuit of the electro 565. The electro 565 'attracts again, advances the The shaft and the wipers of the first selector a second rotary step and again cuts the circuit of the relay 530. The interaction of the electro 565 and the relay 530 continues until the slider 529 finds a battery potential. on the pad C of a block of pads connected to a second free selector, or until the wipers 527, 528 and 529 have been advanced to the eleventh position of the banks.

   In the latter case, the cam contact 507 is actuated and the caller hears
 EMI26.1
 a sina.1 occupa-bion at station A by 1 in-intermediate of the armature spring 509 and the capacitor 505 at the "+" side of the transmission circuit. Operation of cam contact 507 further closes a circuit of relay 550 as follows: earth, armature 515, lower coil of relay 550, armature 558 and its resting pin, armature spring 508, resistor 559, battery, so that the relay 550 attracts and is blocked by the circuit: earth, armature 515, armature 557 and its working contact, upper coil of relay 550, coil of rotation electro 565, battery.

   The high strength of the. upper coil of relay 550 prevents electro 565 from operating on the circuit passing through the upper coil of the relay. 550.



    At armature 557, relay 550 opens the circuit of relay 530,
 EMI26.2
 dn f-Jort (; CJl1 '; the erj rei.i; 1 t of excita Lion of the 565 rotation electro remains cut at the 531 frame, thus preventing the subsequent rotation of the shaft and trotters of the first selector.



   Assuming the second selector according to the. fig. 6 is free and that it has been chosen by the first selector according to FIG. 5, the relay 550 of the first selector is attracted by the circuit: earth, armature 515, lower coil of the relay

  <Desc / Clms Page number 27>

 550, cut-off frame 526, trotter 529, bench block C
 EMI27.1
 connects; [", 1: n t., C) 1: lY 'j2j, conductor 537, 2r;, 1,) tl) rc :: 6'35 and its rest stud, spring caT .-? Rr; l-: 7tLlY'E? 0.2 "j, ',: obina :-(; top of relay iJ2 <.>, battery. The relay r, 20 of the second selector is: '"h'r'le: 1t reached by the e rouit which has just been deorjt pt, a 1 ..' ar:;, a.-ti: r <. 21 and its work block, connects the iJ <J iJ 1. na> j, o îi '.', 7. "7..¯lJ: î and su: ..; 6rj.I.'i l 'of relay 600.

   At armature 557, relay 550 closes a blocking circuit for its upper winding as follows: earth, armature 515, armature 557 and its working pin, upper coil of relay 550, winding,: the rotation electro 565 , battery, the high resistance of the. upper coil of relay 550 preventing operation of electro 565; at armature 555, relay 550 cuts the circuit of electro-ascension 560; at armature 557, it cuts the circuit of relay 530;

   to the armature 558 and its working stud, it short-circuits its own lower winding, thus directly connecting the earth through the armature of
 EMI27.2
 cut 526 to the trotter 529 as guard J.! occupation, 8, insi that to maintain the circuit passing through the upper coil of relay 620 of the second selector; to the frame 554, it connects a multiplied earth to the conductor 272 of the researcher; and, at frames 551, 552 and 553, it extends the transmission circuit from station A to the second selected selector.



   Following formation of the second digit by the calling party, the line relay circuit 500 of the first selector is interrupted a number of times equal to the number of pulses of the second digit. Relay 500 drops momentarily on each pulse and, at armature 502 cuts off the bonding relay 510 circuit. However, relay 510, being delayed release, does not drop during the pulse period. So the circuits controlled by this relay are not disturbed. To armature 502, rela.is 500 transmits a

  <Desc / Clms Page number 28>

 pulse to relay 540 on each de-excitation, via the circuit: earth, armature 502 and its rest pad, armature 512 and its work pad, coil of relay 540, battery.

   Relay 540 attracts and cuts the transmission circuit to armature 541; however, relay 540, being delayed release, does not drop during the pulse period. To armature 501, relay 500 transmits an impulse to line relay 600 (fig. 6) of the second selector each time the circuit is de-energized: earth, armature 501, armature 511 and its working pin, armature 552, wiper 527, bench pad connected to the wiper 527, conductor 535, lower coil of the line relay 600 (fig. 6) of the second selector, armature 621 and its working terminal, upper coil of the relay 600, battery.



  Therefore, the line relay 600 of the second selector attracts and falls on each de-energization and re-energization of the line relay 500 of the first selector. At the armature 601, the relay 600 of the second selector transmits an impulse to the ascending electro 640 and to the lower winding of the rela.is 620 for each de-energization of the line relay 500 of the first selector. This multiple circuit can be established as follows: earth, armature 601, armature 623 and its work terminal, coil of the electro 640, battery, as well as: armature 601, armature 623 and its work terminal, lower coil of the relay 620, battery. This last relay having previously been attracted by its upper winding and being with delayed release, does not drop out during the period of impalsions.

   At armature 622, relay 620 closes the circuit of relay 610 as follows: earth, test conductor 537, armature 633 and its rest pad, armature 622, coil of relay 610, battery, so that this last relay attracts and is blocked by the following circuit: earth, conductor 537, armature 633 and its rest pad, armature 611, coil of relay 610, battery. The zlectro 640 is turned on and off with every

  <Desc / Clms Page number 29>

 energizing and de-energizing the line relay 600, by raising the shaft and the wipers of the second selector by a corresponding number of vertical steps.

   The ascension shaft contact 625 is actuated at the first vertical step, thus disconnecting the upper coil of the relay 620 from the. conductor 537 to the armature spring 626, but this relay remains blocked by its lower winding. At armature 614, relay 610 connects the earth potential to conductor 603 of the communications counter (not shown).



   Shortly after receipt of the last pulse of the second digit, the relay 540 of the first selector drops out and closes a transmission circuit from station A to the second selector at armature 541. The relay 620 of the second selector also drops out at this time, seen that its bonding circuit passing through its lower winding is now cut at the armature 601, which causes the operation of the relay 600 by the circuit: earth, armature 612, armature 634 and its rest pad, cut-off armature 651 of the electro 650, armature 621 and its rest pad, upper coil of relay 600, battery; and, at armature 623, relay 620 closes the circuit of electro 650 as follows: earth, armature 601, armature 623 and its rest pad, winding of electro 650, battery.

   The electro 650 attracts and moves the shaft and the rubbers of the second selector by a horizontal step in the stage chosen by the vertical pulses.



  The operation of the electro 650 also has the effect of cutting the circuit from the line relay (now step relay) 600 to the disconnecting armature 651, so that the relay 600 drops out and cuts the circuit of the electro. 650 to the armature 601. The electro 650 drops back on its turn and closes the circuit of relay 600. The operation of the second selector depends at this time on whether the next comrnutateur connected to the first set of terminals of the stage chosen by the pulses

  <Desc / Clms Page number 30>

 ascent is occupied or free.



   If the next switch is free, the wiper 618 of the second selector receives a battery potential supplied by the next switch on pin C (test) of the first set of pads, and a circuit is established for the combined switching relay and bonding 630 of the second selector as follows: earth, armature 613 and its working pad, lower coil of relay 630, trotter 0'le, pad C connected to .trotter 618, conductor 643, battery potential supplied on conductor 643 of the next switch, so that relay 630. attracts and prevents subsequent rotational pulses of the. second selector.

   If the next switch is busy, the second selector's wiper 618 encounters a ground potential on the C stud of the first set of bank studs and, therefore, the second selector's relay 630 cannot operate at this time. The circuit comprising the upper winding of the relay 600 is therefore maintained at the armature 634 and its rest pad, so that the relay 600 attracts again and restores the circuit of the electro 650. The latter operates again, advance l 'shaft and trotters of the second selector a second rotary step and again cuts the circuit of relay 600.

   This reciprocal action of the electro 650 and the relay 600 continues until the wiper 618 encounters a battery potential on the pin 8 of the connected set of pads; a next free switch or until the trotters 616, 617 and 618 are advanced to the. eleventh position of the benches.

   In the latter case, the cam contact 645 is actuated and a busy signal is sent to the requestor of station A by the armature spring 647 on the "+" side of the transmission circuit. The actuation of cam contact 645 also closes a circuit of relay 630 as follows: earth, armature 613 and its working contact, lower winding of relay 630, armature 638 and its resting contact, reinforcing armature 646, resistor 648, battery, thus causing relay 630 to attract and block by the

  <Desc / Clms Page number 31>

 circuit: earth on conductor 537, armature 633 and its work terminal, upper coil of relay 630, coil of rotation electro 650, battery.

   The high resistance of the upper coil of relay 630 prevents the electro 650 from operating in the circuit comprising this coil. At armature 634, relay 630 cuts the circuit of the upper relay coil 600, and the control circuit of the rotation electro 650 therefore remains cut off at armature 601, thus preventing subsequent rotation of the armature. shaft and trotters of the second selector.



   The switch which follows after the second selector can be another selector (called third selector) of the same type as the second selector, or it can be a connector either of the type according to fig. 7, or of the type according to FIG. 8.



  If the following switch is a third selector inserted in the train, its circuit will be identical to that of the. fig. 6 and its operating mode will be the same as that which has just been described for the second selector. He has. therefore suffices, for the purposes of the. description, d.'indicate this third selector by means of the rectangle 780 in fig. 7, and it is superfluous to give a detailed description.



   It will now be assumed that the connector according to FIG. 7 is the next switch and that this connector is free. In this case, the combined switching and bonding relay 630 of the second selector attracts into the circuit: earth, armature 613 and its working pad, lower coil of relay 630, wiper 618, pad C connected to wiper 618, conductor 643, conductor 727 (fig. 7), armature spring 767, lower winding of. relay 710, battery. Relay 710 also attracts in the latter circuit.

   At armature 633, relay 630 closes a blocking circuit for its upper winding from. earth on conductor 537, la. high resistance of the upper coil of relay 630 preventing the operation of the electro 650. At armature 634, relay 630 cuts the circuit of the upper coil of the relay

  <Desc / Clms Page number 32>

 600, thus preventing the operation of the latter; in frame 633, it opens the circuit of relay 610, thus causing the latter to drop; to the armature 636 and its working stud, it connects the earth directly to the wiper 618 as an occupancy guard, as well as to retain the relay 710 of the connector in the drawn position;

     to armature 637, it connects a multiplied earth to conductor 603 of the communications meter; and, at reinforcements 631 and 632, it extends the transmission circuit from station A to the chosen connector.



   On arma.'cure 712, relay 710 closes an unblocking circuit for itself as follows: earth on conductor 727, armature 712 and its working pad, upper and lower windings of relay 710 in series, battery; at armature 713, it closes a circuit of transfer relay 720 as follows: earth, armature 713, armature spring 772, armature spring 769 and its rest contact, upper coil of relay 720, battery, in
 EMI32.1
 providing 1 excita.tion of relay 720; and, the a.Dfl8.ture 715, it connects the ground potential to the conductor 709 of the communications meter (not shown).



   Following the sending of the third digit by the calling party, the line relay circuit 500 of the first selector is now switched off a number of times equal to the number of pulses of the third digit. Relay 500 momentarily drops off with each pulse and at armature 502 cuts off the circuit of relay 510, which does not drop out during the pulse period. At armature 502, line relay 500 transmits a pulse to relay 540 on each de-energization, so that the latter attracts and cuts the transmission circuit to armature 541.



  As noted above, relay 540 does not drop out during pulse periods. At armature 501, line relay 500 transmits an impulse to line relay 700 (fig. 7) of the connector on each de-energization, via the circuit: earth,

  <Desc / Clms Page number 33>

 armature 501, armature 511 and its working block, armature 552, wiper 527, bench pad connected to wiper 527, conductor 535, armature 631, trotter 616, bench pad connected to wiper 616, conductor 641, conductor 725, upper winding - laughing line relay 700 of the connector, armature 745 and its resting pad, resistor 717, battery. Consequently, connector relay 700 pulls in and drops out on each de-energization and re-energization of line relay 500 of the first selector.

   At the armature 701, the relay 700 transmits an impulse to the ascending electro 770 and to the lower coil of the relay 720 each time the line relay 500 of the first selector is energized. This multiple circuit can be established as follows: earth, armature 701, armature 747 and its resting pad, armature 722, armature 763 and its resting pad, armature spring 773, winding of the electro 770, battery, as well as by 1'armature 701, the armature 747 and its rest pad, the armature 722, the lower coil of the relay 720, battery. As relay 720 has previously been energized by its upper winding and is delayed release, this relay does not drop during the pulse period.

   Electro 770 attracts and falls with each excitation and de-energization of relay 700, raising the shaft and the connector wipers by a corresponding number of vertical steps.



  Ascender shaft contact 766 operates with the first vertical pitch by cutting the circuit from the upper coil of relay 720 to the armature spring 769, but this relay remains blocked by its lower coil.



   Shortly after the reception of the last pulse of the third digit, the relay 540 of this first selector drops out and closes the transmission circuit from station A to the connector to the armature 541. The relay 720 of the connector also drops out at this time, since its bonding circuit comprising its lower winding is now cut at the armature 701, hence the excitation of the relay 760 by the circuit: earth, armature 713, armature spring 772,

  <Desc / Clms Page number 34>

 armature spring 769 and its working block, armature 724 and its rest block, upper coil of relay 760, battery; and, at armature 722, relay 720 cuts the circuit of electro-ascension 770.

   At armature 765, relay 760 closes a circuit of relay 720 as follows: earth, armature 713, armature spring 772, armature 765, upper coil of relay 720,
 EMI34.1
 'oî, t-ter1-e- and,' '. armature î63, rel - '' is 760 transfers the pulse circuit of the ascension electro 770 to. the rotation eleotro 775. The re-energization of relay 720 closes a bonding circuit of relay 760 independently of the voltage shaft contact 771, by the circuit: earth, armatures 713, 764-, armature 724 and its work terminal, upper coil of relay 760, battery.



   Following the sending of the fourth digit by the calling party, the line relay circuit 500 of the first selector is now switched off a number of times equal to the number of pulses of the fourth digit. Relay 500 drops momentarily with each pulse and, at armature 502, cuts the circuit to relay 510, but the latter does not drop out during pulse periods. At armature 502, relay 500 transmits an impulse to relay 540 on each de-energization, thus ensuring the energization of relay 540, which cuts off the transmission circuit to armature 541. Relay 540 does not drop during periods of power. pulse periods.

   At armature 501, relay 500 transmits an impulse to line relay 700 of the connector on each de-energization, by the circuit indicated in the preceding paragraph concerning the transmission of the third digit. So the 700 line relay pulls in and drops out. each de-energization and @ 6-energization of the line relay 500 of the first selector.



  At the armature 701, the relay 700 transmits an impulse to the rotation electro 775 and to the lower coil of the relay 720 on each de-energization of the line relay 500 of the first selector. This multiple circuit can be established as follows: earth, armature 701,

  <Desc / Clms Page number 35>

 armature è'è and its rest block, armature 722, armature 763 and its work block, winding of electro 775, battery, as well as: armature 701, armature 74.7 and its rest block, armature 722, lower winding of the relay 720, battery. Relay 720 does not drop out during this pulse period.



  The electro 775 attracts and falls with each energization and de-energization of the line relay 700, by driving the shaft and the wipers of the connector by a corresponding number of horizontal steps. The walkers 706, 757 and 788 now rest on the multiple connector bank pads of the requested local station.



  Ascension shaft contact 771 is actuated on the first rotary step by opening the circuit from the upper coil of relay 720 to armature spring 772, but this relay is held by its lower coil.



   Shortly after receipt of the last pulse of the fourth digit, the relay 540 of the first selector drops and closes the transmission circuit from station A to. fi connector. the armature 541. The relay 520 of the connector also drops out at this time, since its bonding circuit which includes its lower winding is now cut at the armature 701, by cutting the blocking circuit of the upper winding of the relay 760 at the 'frame 724; and by cutting, at armature 722, the pulse circuit of the rotation electro 775. The relay 760 is of the delayed release type and, therefore, remains attracted for a short period of time. which the requested extension line is tried.



   If the called station is busy, trotter 768 encounters a ground potential on the multiple bank contact of the called station connector. The switching relay 730 cannot therefore operate and the calling station A receives a busy signal (when the connector relay 760 drops) via the following circuit: armature spring 774, armatures 761,

  <Desc / Clms Page number 36>

 731, 751 and their rest pads, capacitor 708 and armature 721 on the negative side of the transmission circuit.

   If the requested station is free, the wiper 722 of the connector encounters a battery potential, coming from the cut-off relay of the requested station, on the multiple bank pad of the connector of the. station requested, Relay 730 closes the circuit: earth, armatures 713, 764, 723, upper coil of relay 730, armature 748 and its rest pad, lower coil of relay 730, wiper 782, bench pad C connected to trotter 788 , multiplication of connector banks, winding of the cut-off relay of the requested station, battery, so that relay 730 attracts and locks in the following circuit: earth, armatures 713, 736, lower winding of relay 730, wiper 788, stud of bank C connected to the slider 768, multiplication of the connector banks, winding of the cut-off relay of the station requested, battery.

   The cut-off relay of the requested station also attracts in the circuits which have just been described, thus freeing the line from the ties.



   The operation of relay 730 closes the signaling circuit of the station requested as follows: conductor 777 of the inrush current generator, armature 742 and its rest contact, armature 734, wiper 787, bench contact "+" connected to the slider 787, ringing loop of the requested station, bench pad "-" connected to the slider 786, slider 786, armature 733, armature 741 and its rest contact, upper winding of the bell cutoff relay 740, armature 752 and its rest pad, armature 762 and its work pad, conductor 774 connected to the "continuous" generator. Relay 740 is not attracted by the inrush AC current flowing through the bell and capacitor of the called station, but the bell is activated immediately.

   



  Relay 760 drops out after a brief interval and transfers the signaling circuit of lead 778 from the "continuous" generator to lead 779 connected to the "interrupted" generator and to the multiple signaling battery. Ringing of the requested extension

  <Desc / Clms Page number 37>

 is then activated automatically intermittently insou '@ what the called party answers or that the caller gives up.

   The calling party at point A perceives a "free" signal during the ringing periods, by the armature 732 and the capacitor 739,
If the call remains unanswered and the calling party at station A decides to give up, he hangs up his handset which has the effect of cutting the line 500 relay circuit of the first selector, so that this relay drops. At armature 502, relay 500 cuts relay circuit 510, but before the latter drops out, there is a momentary closure of relay circuit 540 by armature 514 and its working pin, so that this last relay attracts. After a brief interval, relay 510 drops out and after it relay 540.



  At armature 515, relay 510 removes direct earth from wiper 529 to determine release of the second selector; at frame 515, it also removes the. earth of the upper winding of relay 550, causing the release of relay 550; and, at the armature 513, it removes the earth of the conductor 272 to produce the release of the finder and the cut-off relay 120 of the calling station A. The circuit of the release electro 525 of the first selector closes by: earth, armature 502 and its resting pin, armature 514 and its resting pin, armature 542 and its resting pin, armature 556, armature spring 516 , coil of element 525, battery.

   The operation of the electro 525 causes the release of the first selector of the. manner known in the Strowger system, and the armature 526 of the electro 525 maintains the cut of the circuit of the wiper 529 during the release of the first selector. The circuit of the electro 525 is cut by the armature spring 516 of the ascension shaft contacts 524 when the switching shaft reaches its normal position.



   The removal of the earth from the conductor 272 which returns to the searcher has the effect of cutting the blocking circuit of the

  <Desc / Clms Page number 38>

 upper coil of relay 220 of the researcher, as well as the circuit of cut-off relay 120 of the calling station. Relay 220 drops out and closes the searcher-releasing electro 255 circuit by: earth, armatures 236,211 and their rest pads, armature spring 216 and its working pad, armature 227 and its rest pad, winding of electro 255, driver 494, winding of relay 470 (fig. 4-A), battery.



  The excitation of the electro 255 brings about the release of the. seeker in the manner known in the Strowger system, and the circuit of electro 255 and relay 470 is cut by the armature spring 216 of the ascension shaft contacts 214 when the seeker reaches its normal position. Energizing relay 470 causes a circuit of a common delayed release alarm device (not shown) to close. Releasing the cut-off relay 120 of station A releases the line circuit.



   The release of the second selector operates as follows: removing the earth from the wiper 529 of the first selector (as described in connection with the release of the first selector) has the effect of breaking the blocking circuit of the upper coil of the relay 630 (fig. 6), with release of relay 630. At armature 635, relay 630 closes the circuit of the release elec- tro 605 by: - earth, armature 613 and its rest stud, armature 635, spring armature 627, coil of electro 605, battery; and, at the working pad of the frame 636, it removes the earth from the wiper 618 and from the conductors 643 and 727 going to the connector.

   The energization of the release solenoid 605 releases the second selector of the. manner known in the Strowger system and the circuit of the electro 605 is cut by the armature spring 627 of the ascension shaft contacts 625 when the switching shaft reaches its normal position.

  <Desc / Clms Page number 39>

 



   The release of. connector is made known as follows:
Removing the earth from conductor 727 (as described for releasing the second selector) cuts the blocking circuit of relay 710 (fig. 7), with release of relay 710.



  At armature 713, this relay cuts the blocking circuit of the lower coil of relay 730, thus releasing the latter; at. the armature 713, the relay 710 also removed the earth from the wiper 788 by releasing the cut-off relay of the requested station; and, at armature 715, it removes ground from conductor 709 of the communications meter. At armature 738, relay 730 closes the circuit of electro release 776 by: earth, armatures 714, 738, armature spring 768, coil of electro 776, battery. The energization of the release solenoid 776 causes the connector to release; in the well known Strowger manner, and the circuit of the solenoid 776 is cut by the armature spring 768 of the shaft contacts. ascent 766 when the switching shaft is released.

   Releasing the cutoff relay of the called station returns the line circuit of this station to the normal state.



   If the calling party does not abandon the call, but on the contrary the called party picks up his handset, the call cut-off relay 740 of the connector is actuated by the direct current loop of the. called station. At armature 749, relay 740 is blocked by its lower winding by: earth on armatures 713,749, lower winding of relay 740, .battery; at armatures 741 and 742, it cuts the ringing circuit; to the a.rmatures 741 and 742 and their work pads, it extends the loop of the station called to the battery and to the earth provided by the upper and middle windings of the relay 750; to reinforcements 741 and 742 and their work pads, it extends the transmission circuit from station A to the called station; to armature 744, it connects the battery to the previous switch (second selector) by:

   conductor "+" 726 of the battery, resistor 717, armature 754 and its

  <Desc / Clms Page number 40>

 rest, lower winding of relay 700, armatures 744 and 735, conductor 726. Relay 750 operates in the listening circuit of the requested station and, to armature 735, connects the earth to the previous switch (second selector) by: conductor "-" 725, through the armature 711, 755, armature 745 and its working block, upper coil of relay 700, conductor 725. At armature 754, rela.is 750 removes the battery from the lower coil of the relay 700; and, to the armature 754 and its working pad, connects the earth potential to the lower winding of the relay 700 by: armatures 711, 755, armature 745 and its work pad, armature 754 and its work pad.

   To armature 757, relay 750 connects a multiple earth to the lower winding of relay 740 by: armature 737 and its working contact, armature 749, lower winding of relay 740. To armature 757, relay 750 connects also an earth multiplied with the trotter 788 by: armature 737 and its working stud, armature 736, lower coil of relay 730.

   The transmission current is supplied to the requesting station A by the line relay coils 500 of the first selector and, to the called station, by the upper and middle coils of the relay 750 of the connector,
After that the. conversation has been ended and the two parties have hung up their handsets, the recording of the communication by the communication counter is carried out following (before releasing the switches): The line relay loop 500 of the first selector switch is off when the caller hangs up, and this relay drops out. At the armature 502, the relay 500 cuts the circuit of the relay 510, but, before the latter drops out, a circuit of the relay 540 is closed by the armature 514 and its working pin.

   Therefore, this last relay attracts and, being delayed release, remains attracted for a certain time after releasing the relay 510.

  <Desc / Clms Page number 41>

 



  As soon as the latter releases, a circuit of relay 520 closes by: earth, coil of relay 520, armature 512 and its rest pad, armature 553, wiper 528, bench pad "+" connected to wiper 528, conductor 536 , armature 632, wiper 617, bench pad "+" connects to wiper 617, conductor 642, conductor 726 (fig. 7), armatures 735, 744-, lower winding of relay 700, armature 754 and its rest pad, resistance 717, battery, with excitation of relay 520.

   To armature 521, relay 520 sends an overvoltage via: resistor 523, occupancy key 519, conductor 272, armature 223 (fig. 2), upper coil of relay 220, wiper 265, bench contact connected to the wiper 265, conductor 133 (fig. 1-A), armature 123, armature 111 and its rest pad, winding of the communications counter of the counter station (not shown), causing the operation of this counter. Rectifier 532 prevents surge current from flowing to ground through armature 554.

   At armature 522 and its work pin, relay 520 closes a circuit of relay 540 by: earth, coil of relay 520, resistor 538 at high ohmic value, armature 522 and its work block, coil of relay 540, battery , in order to prolong the bonding action of the relay 540, since the initial circuit of this relay is now cut at the working pad of the armature 514. However, the relay 540 does not stick indefinitely in the circuit which comes from be described and containing the. resistance 538, but falls back after a short interval. On the NO contact of the armature 543, the relay 540 cuts the blocking circuit of the upper winding of the relay 550 and removes the earth of the wiper 529 of the second selector.



  Relay 550 drops out and cuts the circuit from relay 520 to frame 553, causing relay 520 to release after a brief interval. At armature 522, relay 520 disconnects relay 540 from resistor 538 and,.} Armature 521, removes the overvoltage from the station's conversation counter circuit.

  <Desc / Clms Page number 42>

 calling, thus allowing the counter to be released. The relays 540, 550 and 520 trip with a sufficient delay for the communication count to have time to complete.



   If the called party's party does not hang up at the same time as that of calling station A, the conversation count is delayed until the called party hangs up.



  The fact that the called party does not hang up, prevents the battery from being connected through resistor 717 to the lower winding of relay 700, since armature 754 is connected to its working pad and, therefore, the earth through relay 520 (fig. 5) on the "+" conductor going to the connector meets an earth through armatures 711, 755, armatures 745, 754 and their work pads. Under these conditions, the relay 520 cannot attract and the counting does not take place.



  However, relay 540 is kept attracted by: earth, armatures 711, 755, armature 745 and its working pin, upper coil of relay 700, conductor 725, conductor 641 (fig. 6), bench plug "- "connected to baby walker 616, shoe 616, frame 631, conductor 535, bench block" - "connected to baby walker 527 (Fig. 5), baby walker 527, frame 552, frame 511 and its resting stud, frame 522 and its stud idle, winding relay 540, battery. At armature 542, relay 540 keeps the release circuit of the first selector cut off; and, at. the frame 543 and its working stud, maintains the earth on the trotter 529, to keep the second selector in the position (the operation.

   As soon as the called party hangs up, relay 750 of the connector drops, and the. battery is connected to the internal winding of relay 700 through resistor 717 and armature 754 and its rest pad. So, relay 520 attracts and counting is carried out as described in the previous paragraph.



   After the communication a. been registered by the counter, the switches are released in the general manner previously described in this chapter e.g. where the caller of the

  <Desc / Clms Page number 43>

 station A drops the call because the called station does not answer. not.



   If the calling party calls from a private exchange (PBX), for example set B (fig. 1-B), and not from an individual set A (fi.g. 1-A), the associated line circuit will be as shown in fig. 1-B instead of that of fig. 1-A.



  The line circuit of FIG. 1-B differs from that of fig 1-A by the presence of an additional armature 114 to the line relay 110 ', of a work contact associated with the armature 122' of the cutout relay 120 'and of a special test lead (EC) going to the bank multiplication of the line circuit connector.

   The special test lead is grounded by armature 114 when relay 110 'attracts, as well as by armature make contact 122' when cut-off relay 120 'attracts, for a purpose which. will be described in the chapter "Calls from Posts under the Central Office to Private Central Lines under this Office". In all other respects, the line circuits of figs. 1-A and 1-B are identical, and the above description of an urban call by a caller at station A also applies to the caller at station B, with the slight exception that the working block of reinforcement 113 'is connected to pad n 2 of vertical bank 250, instead of being connected to pad n 1 of this bank.



   In the event that all searchers in the first group are busy and another call is initiated on a line terminating at one of the first five floors of the first group of searchers, earth will have been removed from conductor 493 at the time of l engagement of the last seeker, but the relay 440 will have remained attracted from the earth through the armature 457. The relay
 EMI43.1
 450 ocra rcto '.! Fb6 shortly after and will have removed lr. -Gcn''0) of relay 440, thus releasing the latter.

   At armature 441, relay 440 operates the switching of conductor 480 of the starting relay

  <Desc / Clms Page number 44>

 445 to the start relay 445 'of the second group by the conductor 476, the armature 441' and its working pin (assuming that there is at least one free seeker in the second group and that the relay 440 'is actuated accordingly). To the Armaturan;

   464 the relay 440 disconnects the pin 5 of the vertical benches 250 'of the second group of researchers from the conductor 477, thus allowing the researchers of the second group to explore the second series (the five stages of the second group. L 'call'
 EMI44.1
 supra, ai ;; <;> i: e; 1 a (11 :; 1 '-' 'remicr group of lines, will be. lll,; j il "ltCr.Ul (1t taken up by a researcher of the second group of the Lic, .il¯ É .. '¯ "'. '.:

   analogous to that described earlier in this paragraph about a initiated call, and the second group of hunters will continue to serve calling lines from the first group of lines as long as there are no hunters available in the first group. group of researchers.

   Releasing relay 440 further cuts off the associated distributor's electrical circuit 300 to prevent the associated distributor from searching for a free seeker as long as no seeker is available. As soon as a seeker of the first group is free, the relay 440 a. Immediately draws again in the circuit comprising the.

   earth on conductor 493, and the first group of researchers is therefore automatically released for a new use. The calling lines of the second group of lines are transferred to the first group of hunters, when all hunters are on. second group are occupied, in a manner analogous to that which. has just been described in connection with the transfer of a calling line from the first group of lines to the second group of hunters.

     When all the researchers in the first and second groups are busy, the two relays 440 and 440 'drop, with the circuits of the start relays 445 and 445' cut off. Therefore, any call initiated while relays 440 and 440 'are released is delayed until a searcher in a group becomes available.

  <Desc / Clms Page number 45>

 



   Assume now that a searcher of the first group scans one of the first five floors for a calling line and that neither of the trotters C 264 or 265 meets the battery potential of the line cut-off relay. .nte. In this case the seeker's shaft and rubbers rotate to the eleventh position of the banks, with actuation of the cam springs 237. A circuit of the lower winding of relay 460 is closed by: earth, armature 424 , rectifier 459, lower coil of relay 460, conductor 483, armature 204, cam springs 237, resistor 238, battery, with engagement of relay 460. At armature 461, relay 460 cuts off the electro circuit. 245 to prevent subsequent rotation.

   And, at armature 461 and its working pin closes the circuit of the lower coil of relay 230, with energizing of relay 230. At armature 236, relay 230 closes a circuit of electro 300 of the distributor by: earth , armature 236 and its work block, trotter 306, conductor 492, armature 456 and its work block, conductor 491, winding of the electro 300, battery. the electro 300 operates and cuts the circuit of relay 450 to the cut-off armature 301, so that the relay 450 drops out and cuts the circuits of relays 420, 415, 430, 200 and that of the eleotro 300. The release of the electro 300 brings the wipers 305 and 306 of the. distributor on the next free seeker, releasing relay 200 closes the circuit of release solenoid 255 and the seeker is released.



   It will now be assumed that the shaft and the rubbers of the first group seeker are raised by the action of the ascension electro 240 and that the vertical scrubber 253 does not find soil on the first four stages of the. vertical bench 250.



  In this case. earth on the fifth stud of bank 250, connected as follows: reinforcements 429, 442, conductor 472, reinforcement 464 - ', conductor 478, stud n 6 of vertical bench 250, and the multiple conductor to stud 5 of vertical bench 250 bring her

  <Desc / Clms Page number 46>

 rotation of the researcher's shaft and trotters to the eleventh position of the benches. From this point, the operation will be the same as that described in the previous paragraph.



   The operation of the group relay transfer circuit will be explained below. In a previous paragraph of this chapter it has been indicated that the energization of the counting relay of duration 420 (then the initiation of a call in the first group of lines) brought about the connection of an earth potential to the conductor 417. transfer counter 438 through armature 421. This grounding of conductor 417 operates counter 438, which then alternately connects pulses of earth potential to conductors 418 and 419 from that counter.

   The earth pulses on the conductors 418 and 419 are used for the adjustment of the correct operation of the searchers and are spaced so as not to interfere with the normal operation of the latter. The relay 420 operates for brief periods not exceeding half a second, the operation of the finder being very fast.



    However, if abnormal conditions occur in the operation of the finder and associated common relay group, this would indicate that a finder is taking an unreasonable amount of time to find a calling line, and the relay 420 would remain drawn beyond the normal time. , thus triggering the following operations: An earth pulse on conductor 418 closes the circuit of the lower winding of relay 405 by means of armatures 422 and 412 thus activating relay 405, which is blocked to earth by its upper winding and the armature 407. At armature 406, relay 405 connects the upper coil of relay 410 to conductor 419 of the counter.

   After a new interval, the counter 438 applies an earth pulse to the conductor 419, thus closing the circuits by the upper coil of the relay 410 and activating the latter, which locks in the circuit: earth on the conductor 493 '(at , suppose that a researcher is

  <Desc / Clms Page number 47>

 available in the second group), armatures 409, 408 ', conductor 474, transfer correction key 403, armature 411, lower coil of relay 410, battery.

   At armature 413, relay 410 closes an obvious circuit of relay 400, so that relay 400 pulls and locks to ground from transfer correction element 404 .; at armature 409, this relay cuts the circuit of relay 440, which releases; the relay 410 further closes a circuit of the electro 300 of the distributor by the armature 414; and, at armature 414, further bypasses relay 450, thus cutting off the blocking circuit of relays 420 and 405.



  At armature 402, relay 400 closes an alarm supervision circuit (not shown) to draw the supervisor's attention to this transfer. Releasing relay 400 transfers conductor 480 from. starter relay 445 to starter relay 445 'to armature 441; and, at frame 464 removes soil from pin # 5 of vertical bank 250 'of the second group seeker to allow that seeker to explore the top five floors to find the calling line of the first group of lines. Relay 445 drops out and releases the solenoid 300 of the distributor, as well as all the relays activated in the relay group of fig. 4 except relays 400 and 410, which are blocked by the. transfer correction key.

   The release of the electro 300 causes the wipers 305 and 306 to move away from the searcher occupied in the first group. The calling line of the first group of lines, which caused the transfer set in time, is now the responsibility of the second group of researchers.



   Under the conditions indicated in the previous paragraph, relay 410 will remain energized until all researchers of the second group are occupied, or the supervisor releases the transfer correction key, and relay 400 will remain activated until this release. . When relay 410 drops out, relay 440 attracts again and transfers the con-

  <Desc / Clms Page number 48>

 driver 480 from start relay 445 'to start relay 445.



   If all the researchers of the second group are busy when the relay 410 draws, the latter cannot get stuck in the a.t-pulled position, since there is no earth on the conductor 493 '. Therefore, the relay 410 remains attracted for the duration of the earth pulse on the conductor 419, which is however long enough to produce the drive of the rubbers 305 and 306 of the distributor to another seeker of the first group. When relay 410 drops out at the end of the ground pulse on conductor 419, relay 440 attracts again and transfers conductor 480 from start relay 445 'to start relay 445.



   Calls from Extensions under the Main Office (Main Stations) to Private Offices under this Office (Main Private Offices (PBX).



   The lines (fig. 1-B) of each subscriber to a private exchange (PBX) are grouped together so as to represent successive numbers on the same floor of connector banks assigned to the group of the private exchange, and the connectors associated with these benches are arranged as shown in fig. 8, instead of as shown in fig. 7. All the additional test bench pads EC of such a private exchange group, except those which correspond to the last number of this group, are connected to the corresponding EC conductors coming from the lines of the group. These pads and these conductors are intended to automatically choose a free line in this group, in the following manner.



   During a local call to a private exchange line or multi-line installation (PBX), initiating the call, actuating the searcher, group relays, distributor, first selector and second selector operate as described in the chapter "Calls from Post Office

  <Desc / Clms Page number 49>

 Main to Individual Post Lines reporting to the Main Office ", it is therefore unnecessary to discuss these bodies again in this chapter.



   It will now be assumed that the FBX private exchange connector in fig. 8 is free and can be used to establish the connection with the PBX lines (fig. 1-B). In this case, the combined switching and bonding relay 650 of the second selector is actuated by: earth, armature 613 and its stud. working, lower coil of relay 630, wiper 618, bench block C connects to wiper 618, conductor 643 (fig. 6), conductor 827 (fig. 8), armature spring 867, lower coil of relay 810, battery . Relay 810 also operates in the circuit just described.

   To the armature 636 and its working block, the relay 630 connects the direct earth to the trotter 618 as an occupancy guard, as well as to retain the bonding relay 618 of the connector in the pulled out position.



  At the armature 812, the relay 810 closes a bonding circuit for itself by: earth on the conductor 827, armature 812 and its working pad, upper and lower coils of relay 810, battery; at armature 813, it closes a circuit of relay 820 by: earth, armature 813, armature spring 872, armature spring 869 and its rest pin, lower winding of relay 820, 'battery, from where engagement relay 820; and, at armature 815, relay 810 connects an earth potential to conductor 809 of the communications counter (not shown).



   Following formation of the third digit by the caller, the line relay circuit 500 of the first selector is cut a number of times equal to that of the pulses of that digit.



  Relay 500 drops momentarily with each pulse and, at armature 502, cuts the circuit to relay 510, but the latter does not drop during the pulse periods. At armature 502, relay 500 transmits an impulse to rela.is 540, and this

  <Desc / Clms Page number 50>

 the latter drops out and cuts off the transmission circuit to armature 541. Relay 540 does not drop out during the pulse period.

   To armature 501, relay 500 transmits an impulse to line relay 80 @ (fig. 8) of the connector via: earth, armature 501, armature 511 and its working pin, armature 552, wiper 527, bench connected to the slider 527, conductor 535, armature 631, slider 616, bench stud connected to the slider 616, conductor 641 (fig. 6), conductor 825 (fig. 8), upper coil of the line relay 800 of the connector, armature 845 and its rest pad, resistor 817, battery. So relay 800 pulls in and drops out on each de-energization and re-energization of row relay 500 of the first selector. At armature 801, relay 800 transmits an impulse to the vertical electro 870 and to the upper coil of relay 820 each time the line relay 500 of the first selector is de-energized.

   This multiple circuit is established as follows: earth, armature 801, armature 847 and its rest block, armature 893 and its rest block, armature spring 873, winding of the electro 870, battery, as well as: armature 801 , armature 847 and its rest pad, armature 822, upper coil of relay 820, battery.



  As relay 820 was previously energized by its lower winding, and it is with delayed release, it does not drop during the pulse period, The electro 870 attracts and falls on each excitation and de-energization of relay 800 in raising the shaft and the connector trotters a corresponding number of vertical steps. The 866 ascension shaft contacts work with the first vertical step by cutting the circuit from the lower coil of relay 820 to armature spring 869, but relay 820 remains blocked by its
 EMI50.1
 bobiinn.t; e Sl1: l. rh: l #.

   Fire 8.1) n'.s upon receipt of the J., rn.icr2 inrhulsiorl of the third digit, the relay 540 of the first selector drops out and closes the transmission circuit from station A to the connector to the armature

  <Desc / Clms Page number 51>

 541. The connector relay 820 also drops out at this time, since its bonding circuit including its upper winding is now cut at the armature 801, so that the relay 890 attracts by: earth, armature 813, armature spring 872, armature spring 869 and its working block, armature 824 and its rest block, lower coil of relay 890, battery.

   In frame 894, relay 890 closes a circuit of relay 820 by:
 EMI51.1
 earth, armature E13, armature resaort 872, armature 894, lower winding of relay 820, battery; at armature 895, it closes the circuit of relay 860 par. earth, armature 813, armature 895 and its working pin, winding of armature 893, and transfers the pulse circuit of the ascension electro 870 to
 EMI51.2
 the rotation eleotro> <> 7 d;

   and, as the armature 13 p i, connects the battery to the LI 369 by its upper winding. re-operation of relay 820 has the effect of closing a bonding circuit of relay 11) independently of the shaft contacts of rotation 871 by: earth, armature 813, armature 835 and its working pin, armature 824 and its work, lower winding of relay 890, battery.



   In addition to sending the fourth digit by the caller, the line relay circuit 500 of the first selector is now turned off a number of times equal to the number of pulses of the digit. Relay 500 drops momentarily with each pulse and, at armature 502, cuts the circuit to relay 510, but the latter does not drop during the pulse period.



  At armature 502, relay 500 transmits a pulse to relay 540, which turns on and off the transmission circuit to armature 541. Relay 540 does not drop during the pulse period. At the armature 501, the relay 500 transmits a pulse to the line relay 800 of the connector through the circuit indicated in a previous paragraph concerning the transmission of the third digit.

   Line relay 800 is therefore attracted and released each time the line relay 500 is de-energized and re-energized.

  <Desc / Clms Page number 52>

   first selector. At armature 801, relay 800 transmits an impulse to the rotation electro 875 and to the upper coil of relay 820 on each de-energization of line relay 500 of the first selector.

   This multiple circuit can be established as follows: earth, armature 801, armature 847 and its rest pad, armature 893 and its work pad, winding of the electro 875, battery, as well as: armature 847 and its rest pad, armature 822, upper coil of relay 820, battery. relay 820 does not drop out during the pulse period. the electro 875 attracts and falls each time relay 800 is energized and de-energized by turning the shaft and the contact pads of the connector by a corresponding number of steps.

   The trotters 886, 887, 888 and 889 now rest on the multiple bank pads of the connector that controls the first line circuit of the called PBX group. The shaft contacts of rotation 871 operate with a first rotary pitch by breaking the circuit of the lower coil of relay 820, but the latter is held by its upper coil.



   Shortly after receiving the last pulse of the fourth digit, the first selector relay 540 drops and closes the transmission circuit from station A to connector at armature 541.

   The connector relay 820 also drops out at this time, because its bonding circuit via its upper winding is cut off at the armature 801, with the blocking circuit of the lower winding of the relay 890 at the armature 824 being cut. relay 890 has a delayed release and therefore remains attracted for a brief interval during which the test of the first line of the PBX group takes place.



   If the. first PBX line is busy, the trotter 888 encounters an earth potential on the multiple bank stud of the connector which controls this line. Therefore, the switching relay 830 cannot operate at this time. The 889 slider will also find soil on the EC multiple bank stud of the

  <Desc / Clms Page number 53>

 connector controlling the first line, this earth potential being supplied either by the armature 114 of the line relay 110 '(fig. 1-B) of the first line, or by the armature 122' and its relay working pin 120 'cut-off.

   The earth potential applied by the EC 889 wiper excites the upper winding of relay 890 before the latter can drop out, so that this relay is kept attracted. Relay 800 is also energized by: earth on the EC 889 wiper, armatures 891, 823, circuit breaker 859 of the electro 875, armature 819, armature 844 and its rest pad, lower winding of relay 800, armature 854 and its rest pad, resistor 817, battery.

   At armature 801, relay 800 closes the circuit of electro 875 by: earth, armature 801, armature 847 and its resting pad, armature 895 and its working pad, winding of electro 875, battery, so that the electro 875 energizes and turns the shaft and the connector trotters with a new rotary pitch to the bench pads of the second line of the PBX group. At the cut-off armature 859, the electro 875 cuts the circuit of the relay 800, which drops out and cuts the circuit of the electro 875 at the armature 801. The electro 875 in turn drops and closes the circuit. relay 800. Assuming that this PBX group consists of three line circuits, the operation of the connector at this time depends on whether the second line in the group is busy or free.



   If this line is busy, the trotter 888 encounters a ground potential on the multiple bank pad C of the connector controlling the second line. Therefore, relay 830 cannot a.tract at this time. The slider 889 also encounters a ground potential on the EC multiple connector bank pad of the second line, and the upper coil of relay 890 is energized by this latter ground potential before the release of relay 890.

   This last relay is therefore kept attracted

  <Desc / Clms Page number 54>

 and the relay 800 is re-energized and closes the circuit of the electro 875. The electro 875 is re-energized, advances the shaft and the wipers of the connector to the third and last line of the group, and cuts the circuit again. relay 800. This drops out and cuts off the circuit of electro 875 again.



  If the third row is busy, the trotter 888 finds a ground potential on the C connector multiple bank pad of the third row, but the slider 889 does not find a ground potential on the corresponding EC multiple connector bank pad seen. that the third row is the last of the group. Under these conditions, the relay 830 cannot attract, the relay 890 drops out and the relay 800 cannot cause a step of the electro 875 to move the shaft trotters away from the studs on the bench. third line.

   The busy signal is supplied to the calling station by armature spring 874, armatures 861, 831, 851 and their rest pads., Capacitor 808, and armature 821 on the negative side of the trans. - mission.



   We will now assume that one of the three lines was free at the time of the test by the conncoter. In this case, the trotter 888 finds a battery potential, coming from the cut-off relay of the, free line on the multiple connector bank pad 0 of the free line, while the ruber 889 does not find, ruas of potential of. earth on the EU connector multiple bank stud of the free line.

   The circuit of relay 830 then closes by: earth, armature 813, armature 895 and its rest pad (relay 890 having fallen in the meantime), armature 863, upper coil of relay 830, armature 848 and its rest pad, winding lower relay 830, Des trotter, bank pad C connected to slider 888, multi-connector bank, winding of the cut-off relay from the free line, battery, so that the relay 830 attracts and locks to earth in the following circuit:

   underwire 813, 836, lower bobiriage

  <Desc / Clms Page number 55>

 of relay 830, wiper 888, bank pad C connected to wiper 888, multiple connector bank, winding of the covpure relay. selected line, battery. The cut-off relay of the chosen line also operates in the indicated circuit, by freeing the line from the clips.

   the description of the establishment of the ringing circuit, of the signaling of the selected line of the PBX group, and of the answer to the call obtained from the selected line, is the same, as that which was made in detail for the connector of individual lines in the chapter entitled "Calls from Posts under the Main Office (Main Posts) to Individual Line Posts falling under the Main Office (Individual Lines (the Main Posts), with the only exception that the first digit of each reference number is "8" instead of "7." There is therefore no need to repeat this detail.



   The communication count, the. releasing the first selector and releasing the second selector operate as for the connection described in the chapter just cited. The release of the PBX line connector is the same as for the single line connector described in the above chapter, with the only exception that the first digit of each reference number is "8" instead of "7".



  These details will therefore not be repeated in this chapter.



   Local Calls to the Satellite Office (Branch Office).



   In order to describe in detail a local call from a satellite office, it has been assumed that station C (Fig. 11) sends a call to another station in the same office. It was also assumed that the rubbers 1124, 1125 and 1126 of the finder 1108 were found and connected to the line circuit 1107 of the station C in a manner analogous to that described in chapter
 EMI55.1
 "hpe7¯s dc; posts under the ii'rine Bureau; 1 = pril 8.llXPc, stec of Lines = ¯v:? ¯LVi.dm7¯lf .; relev:, nt of Bureau Br.Lncipa.1".

   We have. further assumed that the trotters 1237, 1238 and 1239 of the researcher

  <Desc / Clms Page number 56>

   outgoing junction chcur (Fig. 12) are located on a junction going to a free outgoing junction circuit as shown in fig. 13. Under these conditions, relay 1100 of the selector
 EMI56.1
 tor of OOl!:, mtatiol1 is IIl8.intp-nu attracted on the calling loop of set C. At the armature 1102, the relay 1100 completes an obvious circuit to stick the relay 1110, from where the latter is energized.

   To armature 1113, relay 1110 connects the earth potential to conductor 1129 through conductor l190, armatures 1215, 1255, conductor 1189, rectifier 1137 and occupant key 1109, to maintain finder 1108 and line circuit cut-off relay 1107. The relay 1110 also closes a circuit of the relay 1230 by: earth, armature 11-15, conductor 1200, armature 1257 and its rest pin, armature spring 1247 and its rest pin , the lower winding of relay 1230, battery, with energization of relay 1230.

   At armature 1235, relay 1230 closes a circuit of relay 1210 by: armature 1135 and its rest pad, conductor 1205, armature 1235, upper coil of relay 1210, trotter 1259, bench pad connected to trotter 1239, battery supplied on conductor C of the outgoing junction circuit connected to the aforementioned bench stud, so that the relay 1210 attracts and locks to earth by the armature 1115, resting pin of the armature 1172, armatures 1156, 1167 , conductor 1206, armature 1218 and its working stud, lower winding of relay 1210. The application of earth by the upper winding of relay 1210 to trotter 1239 has the effect that the outgoing junction circuit connected to trotter 1237, 1238 and 1239 is entered as described in the chapter "Calls from.

   Satellite Office (Branch Office) at the Main Office ".



  * At armature 1219, relay 1210 directly connects earth to wiper 1239 as an occupancy guard, as well as to retain the outgoing junction circuit entered. At armature 1216, relay 1210 terminates a circuit of relay 1130 as follows: earth,

  <Desc / Clms Page number 57>

 armature 1113 and its work pin, conductor 1190, armature 1216, conductor 1191, upper coil of relay 1130, battery, so that the -¯relay 1130 attracts and is blocked to the earth by armature 1113 and its work pin and the armature 1139. At the armatures 1212 and 1213, the relay 1210 extends the transmission circuit of the calling station C to the outgoing junction circuit seized, through the wipers 1237 and 1230.

   At armature 1131, relay 1130 sends the operating (or transmission) signal back to the caller via: armature 1131 and its working pin, armature resting pin 1141, conductor 1185, armature 1232 and its work pad, conductor 1184, lower coil of relay 1100, conductor 1128, wiper 1125, conductor 1118, line circuit 1107, station C conversation circuit. Having heard the known maneuver signal, the caller dials the number of. desired local extension.



   It will be assumed that the number of the local extension requested is 50.1599 and that the discrimination in the switching selector (or discriminator) between a local number and a main office number occurs after the second digit. In this case, the right rest shaft contact 1147 is set to make contact when the shaft of this selector reaches the fifth stage (the first digit of the local number being 5) while the shaft contact Left idle 1148 is set to make contact when the shaft of this selector reaches the tenth stage (the second digit of the local number being 0). After forming the first digit (5), the circuit of the switching selector relay 1100 (discriminator selector) is interrupted five times.

   The relay 1100 drops out momentarily after each pulse and, at the armature 1102, cuts the circuit of the bonding relay 1110. However, the latter, being with delayed release, does not drop again during the period of pulses, therefore the circuits. controlled by the

  <Desc / Clms Page number 58>

 relay 1110 are not disturbed. At the armature 1102 and its rest pad, the relay 1100 transmits a pulse to the ascending electro 1260, to relay 1240 and to the upper winding of relay 1230, on each de-energization.

   This multiple circuit can be established as follows: earth, armature 1102 and its rest pad, armature 1114, conductor 1180, armature 1231, coil of electro 1260, battery; on the other hand, as follows: earth, armature 1102 and its rest pad, armature 1114, conductor 1100, coil of relay 1240, battery; and, as follows: earth, armature 1102 and its rest pad, armature 1114, conductor 1180, armature 1231, upper coil of relay 1230, battery. Relay 1240 pulls in and, being delayed release, does not drop out during the pulse period.

   To armature 1244, relay 1240 connects a multiplied earth to the upper winding of relay 1130. Relay 1230 is also delayed release and does not drop out during pulses after the circuit of its lower winding has been cut by the spring in the armature. .rmature 1247 of the ascension shaft contact 1245. The electro 1260 is energized and falls again with each de-energization and re-energization of relay 1100, raising the shaft and the trotters of the switching selector (discriminating selector) a corresponding number of vertical steps (in this case the shaft and the rubbers are raised to the fifth floor).

   The ascension shaft contact 1245 works with the first vertical pitch by opening the circuit from the lower coil of the relay 1230 to the armature spring 1247, but the relay 1230 is stuck by its upper coil and by the fact that it is delayed release during pulses. Shortly after receiving the first pulse of the first digit, relays 1240 and 1230 drop out. At. armature rest pad 1232, relay 1230 replaces the operating signal with direct earth.

   At armature 1234, relay 1230 closes a circuit of the release electro 1275 by: earth, armature 1234,

  <Desc / Clms Page number 59>

 conductor 1194, armature 1142 and its resting stud, right-hand repus shaft contact 1147 (now actuated because the discrimination selector shaft has been raised to the fifth stage), armature 1133, conductor 1196, winding of the electro 1275, battery. The energization of the electro 1275 causes the shaft of the gravity discriminator selector to drop to the normal position and the circuit of the electro 1275 is cut at the right rest shaft contact 1147. The shaft contact of ascension 1245 returns to rest when the shaft of this selector is released.

   The excitation of electro 1275 also closes a circuit of relay 1140 by: earth, armature 1115, conductor 1200, armature 1277 and its working pin, conductor 1198, armature 1144 and its resting pin, upper winding of the relay 1140, battery, and a second circuit of relay 1140, by: earth, armature 1115, conductor 1200-, armature 1277 and its working pin, conductor ll98, armature 1144 and its resting pin, lower winding of relay 1140, armature 1145 and its rest pad, frame 1154 and its rest pad, frame 1164, resistor 1168, battery. However, the relay 1140 cannot attract in the circuits which have just been indicated, because its two coils are excited in opposite directions.



  The cutting of the two circuits of the windings of relay 1140 to the armature 1277 by the release of electro 1275, produces a momentary magnetic imbalance between the two windings of relay 1140 and, consequently, the latter attracts and is blocked by: earth, armatures 1115, 1146, lower and upper windings of relay 1140 in series, battery. Triggering of the ascension shaft contact 1245 closes a circuit of relay 1250 by: earth, armature 1115, conductor 1200, armature 1257 and its resting pin, armature spring 1247 and its resting pin, winding lower relay 1230, battery.

   So the 1230 relay draws to. new 'and maintains direct earth by: lower coil of the relay

  <Desc / Clms Page number 60>

 1100, armature 1141 and its work block, conductor 1185, armature 1232 and its work block, conductor 1184.



   Following the formation of the second digit (0), the circuit of relay 1100 is cut ten times and pulses are transmitted accordingly to the ascension electro 1260, to the relay 1240 and to the upper coil of the relay 1230 from the earth and the rest contact of the armature 1102. The relays 1240 and 1230 do not drop during the pulses. The electro 1260 pulls in and falls with each impulse, raising the shaft and the discriminator selector wipers to the tenth floor of the benches.



   Shortly after receiving the last pulse of the second digit, relays 1230 and 1240 drop out. At the rest pad of the armature 1232, the relay 1230 maintains the direct earth on the lower winding of the relay 1100; and at armature 1234, it closes a release circuit for the electro 1275 by: earth, armature 1234, conductor 1194, armature 1142 and its working pin, left rest shaft contact 1148, (now actuated because that the disoriminator selector shaft has been raised to the tenth stage), armature 1151 and its resting stud, armature 1133, conductor 1196, coil of electro 1275, battery. The energization of the electro 1275 causes the shaft of the discriminator selector to drop by gravity to the rest position, and the circuit of this electro is cut at the left rest shaft contact 1148.

   Ascension shaft contact 1245 returns to rest when the shaft reaches its normal position. The excitation of electro 1275 also closes a circuit of relay 1150 by: earth, armature 1115, conductor 1200, armature 1277 and its work pin, conductor 1198, armature 1144 and its work pin, armature 1153 and its rest pad, upper coil of relay 1150, battery; as well as a second circuit of relay 1150 by: earth, armature 1115, conductor 1200, armature 1277 and its working pin,

  <Desc / Clms Page number 61>

 conductor 1198, armature 1144 and its work block, armature 1153 and its rest block, lower coil of relay 1150, armature 1145 and its work block, armature 1154 and its rest block, armature 1164, resistor 1168, battery.



  However, relay 1150 does not attract, because its two coils are energized in opposite directions. The cutting of the two circuits of relay 1150 to armature 1277 by the release of electro 1275 causes a momentary magnetic imbalance between the two coils of relay 1150 and, consequently, relay 1150 attracts and locks in the circuit: earth , armature 1115, armature 1155, lower and upper windings of relay 1150 in series, battery. At armature 1156, relay 1150 cuts off the blocking circuit of the lower winding of relay 1210, hence triggering of the latter. Releasing relay 1210 disconnects the transmission circuit from the outgoing junction to armatures 1212 and 1213; and, at armature 1219, removes earth from wiper 1239 to free the seized outgoing junction circuit.

   Triggering of the ascension shaft contact 1245 closes a circuit of relay 1230 by: earth, armature 1115, conductor 1200, armature 1257 and its resting pin, armature spring 1247 and its resting pin, lower winding of the relay 1230, battery, so that the relay 1230 draws again and maintains the direct earth on the lower winding of the relay 1100 by: armature 1141 and its work pin, conductor 1185, armature 1232 and its work pin, conductor 1184.



   Following the formation of the third digit (1), the circuit of relay 1100 is cut once. Relay 1100 momentarily drops once, and at armature 1102 cuts the circuit to relay 1110, but the latter does not drop.



  At armature 1102 and its rest pad, relay 1100 transmits an impulse to the ascension electro 1260, to the relay

  <Desc / Clms Page number 62>

 1240 and to the upper coil of relay 1230 by a multiplied circuit described in the previous paragraph concerning the pulses of the first digit. Relays 1240 and 1230 do not drop as a result of this pulse. The Eleotro 1260 pulls in and out by raising the shaft and the discriminating selector wipers by a vertical step.



   Shortly after receiving the pulse of the third digit, relays 1240 and 1230 drop out. At rest pad of armature 1232, relay 1230 maintains direct earth on the lower winding of relay 1100. At armature 1234, relay 1230 cuts a circuit of relay 1160 by: earth, armature 1234, conductor 1194, armature 1162 and its resting stud, wiper 1139 of vertical bench 1138, pin no.1 of vertical bench 1138, armature 1152, conductor 1197, armature 1276, conductor 1202, lower and upper windings of relay 1160 in series, battery, of so that the relay 1160 attracts and blocks in the circuit: earth, armatures 1115, 1165, lower and upper windings of relay 1160 in series, battery. At armature 1231, relay 1230 cuts the circuit of its upper winding as well as of the ascension electro 1260.

   At armature 1166, relay 1160 closes the circuit of relay 1220 by: earth, armature 1115, conductor 1200, armature 1257 and its resting pin, armature spring 1247 and its working pin, conductor 1201, armature 1166, conductor 1204, cut-off armature 1266, coil of relay 1220, battery, from where energization of relay 1220. The discrimination selector is now ready to turn its wipers to choose a second free local selector.



   The excitation of relay 1220 closes the circuit of the rotation electro 1265 by: earth, armature 1234, conductor 1194, armature 1162 and its working pin, conductor 1195, armature 1221, winding of electro 1265, battery. Electro 1265 attracts and rotates the selector shaft and rubbers

  <Desc / Clms Page number 63>

 Disoriminator (switching selector) of a step in the first stage of banks (stage "1" chosen by the impulse of the third digit). The energization of the electro 1265 further cuts the circuit of the relay 1220 to the disconnecting armature 1266, so that this relay drops out and cuts the circuit of the electro 1265 to the armature 1221. The electro 1265 drops out. in turn and closes the circuit of relay 1220.

   The operation of the discrimination selector at this time depends on whether the second selector connected to the first set of bench pads of the first stage is occupied or free.



   If the second selector is free, the wiper 1229 of the discriminator selector finds a battery potential supplied by the second selector on the pin C of the first set of bench pads and a circuit for the relay 1250 is closed by: earth, armature 1115 , conductor 1200, armature 1277 and its rest pad, upper coil of relay 1250, wiper 1229, bench pad C connected to wiper 1229, battery supplied by the second selector to the aforementioned bench pad, so that relay 1250 attracts and Prevents subsequent rotational pulses of the discriminator selector by cutting the circuit from relay 1220 to armature 1257.

   If the second selector is occupied, the wiper 1229 of the discriminator selector finds the earth potential on the pin C of the first set of bank pads and, therefore, the relay 1250 of this selector cannot attract at this time. . Therefore, the circuit of the relay 1220 is maintained at the armature 1257 and its rest pad, causing a re-use of the relay 1220 which closes the circuit of the electro 1265. The latter is energized again, advances the shaft and the contactors of the switch. 'a second rotation step and again cuts the circuit of relay 1220.

   This reciprocal action of the electro 1265 and the relay 1220 continues until the wiper 1229 finds a battery potential.

  <Desc / Clms Page number 64>

 on the stud C of a set of bench studs connected to a second free selector or until the rubbers 1227, 1228 and 1229 are advanced to the eleventh position of the banks. In the latter case, the cam contact 1225 is actuated and the busy signal is returned to recall at station 0 by the armature spring 1223 and the capacitor 1105 at the "+" side of the transmission circuit.

   The actuation of the cam contact 1225 also has the effect of closing a circuit of the relay 1250 by: earth, armature 1115, conductor 1200, armature 1277 and its rest pin, upper coil of relay 1250, armature 1258 and its rest pin , armature spring 1224, resistor 1226, battery, so that the relay 1250 attracts and blocks by the circuit: earth, armature 1115, conductor 1200, armature 1257 and its working pin, lower coil of relay 1250, winding of electro rotation 1265, battery.

   The high resistance of the lower winding of relay 1250 prevents electro 1265 from drawing into the circuit containing the lower winding of relay 12500 At armature 1257, relay 1250 opens the circuit of relay 1220, so that the control circuit of the electro 1265 remains cut at the armature 1221 thus preventing the subsequent rotation of the shaft and of the rubbers of the discrimination selector.



   If the second selector shown in fig. 6 is located in the branch office, is free and has been chosen by the discriminator selector in figs. 11 and 12, the relay 1250 of the latter selector is attracted by its upper winding in the manner described in the first part of the preceding paragraph.

   At armature 1257, relay 1250 closes a blocking circuit for its lower winding by: earth, armature 1115, multiple signal generator or "multiple ground" (multiple ground), armature 1135, conductor 1200, armature 1257 and its stud working, lower winding of relay 1250, winding of electro 1265, battery, high winding resistance

  <Desc / Clms Page number 65>

 lower relay 1250 preventing operation of electro 1265;

   at armature 1257, relay 1250 cuts the circuit of relay 1220; to the armature 1258 and its working stud, it short-circuits its upper winding, thus connecting the continuous signal generator or "direct ground" (direct ground) by the armature 1277 and its rest contact to the wiper 1229 to as an occupation guard, and closes the upper coil circuit of relay 620 of the second selector; at frame 1254, it connects the multiple signal generator to lead 1129 of finder 1108; and, at frames 1252 and 1253, extends the transmission circuit from station C to the second selected selector.



   Following the formation of the fourth digit (5), the circuit of the relay 1100 is interrupted five times and the pulses are transmitted accordingly to the relay 1240 by the earth and the rest pad of the armature 1102. The relay 1240 attracts with the first pulse and cuts the transmission circuit from the second selector to armature 1241. At armature 1101, relay 1100 transmits an impulse to line relay 600 (fig. 6) of the second selector at each de-energization, by: earth , armature 1101, armature 1111 and its work block, conductor 1181, armature 1252, wiper 1227, bench pad connected to the wiper 1227, conductor 1285, conductor 535, lower coil of relay 600 of the second selector, armature 621 and its contact pad work, upper coil of relay 600, battery.

   So the line relay 600 of the second selector pulls in and drops for each de-energization and re-energization of the line relay 1100 of the discriminator selector. From this moment on, the operation of the second selector is the same as that described in the chapter "Calls for sets under the Main Office (Main Posts) and Individual Extension Lines under this Office (Main Individual Lines)"; it is therefore unnecessary to repeat these details in these chapters.



   It will now be assumed that the connector according to FIG. 7

  <Desc / Clms Page number 66>

 shows, in the main office switching train, the switch which succeeds the second selector according to FIG. 6, and that this connector is free. In this case, the relay 630 of the second selector attracts by: earth, armature 613 and its working stud, lower coil of relay 630, wiper 618, bench pad C connected to wiper 618, conductor 643, conductor 727 (fig. 7) , armature spring 767, lower coil of relay 710, battery. Relay 710 also operates in this circuit.

   At armature 633, relay 630 closes a blocking circuit for its upper winding by: earth on conductor 537, armature 633 and its working pin, upper winding of relay 630, winding of electro 650, battery, resistance high of the upper winding of relay 630 preventing operation of electro 650; at armature 634, relay 630 cuts the circuit of the upper winding of relay 600.

   At armature 633 it cuts the circuit of relay 610 by releasing the latter; at armature 636 and its working pin, it connects the direct earth to the wiper 618 as an occupancy guard, as well as to retain the relay 710 of the connector in the drawn position; to armature 637, it applies a multiple signal to conductor 603 of the communications counter, and to armatures 631 and 632 extends the transmission circuit from station C to the chosen connector.



   The bonding relay 710 of the connector attracts as described in the previous paragraph. At the armature 712, this relay closes a blocking circuit for itself by: on conductor 727, armature 712 and its working terminal, upper and lower windings of relay 710 in series, battery; to armature 713, it closes a circuit of relay 720 by: earth, armature 713, armature spring 772, armature spring 769 and its resting pin, upper coil of relay 720, battery, by attracting the relay 720; to armature 715, connects the potential of

  <Desc / Clms Page number 67>

 earth to conductor 709 of the communications counter (not shown).



   Following the formation of the fifth digit (9), the circuit of the discriminator selector relay 1100 is interrupted nine times and the pulses are consequently transmitted to the relay 1240 by: earth, rest pad of the armature 1102.



  Relay 1240 attracts with the first pulse and cuts the transmission circuit to armature 1241. At armature 1101 this relay transmits a pulse to line relay 700 of the connector on each de-energization by: earth, armature 1101, armature 1111 and its work block, conductor 1181, armature 1252, wiper 1227, bench pad connected to wiper 1227, conductor 1285, conductor 535, armature 631, wiper 616, bench pad connected to this wiper, conductor 641, conductor 725, upper winding of the relay 700 of the connector, armature 745 and its resting pad, resistor 717, battery. The line relay 700 of the connector therefore attracts and falls on each de-energization and each re-energization of the line relay 1100 of the discriminator selector.

   At armature 701, relay 700 transmits an impulse to electro-lift 770 and to the lower coil of relay 720 on each de-energization of line relay 1100 of the discriminator selector. This multiplied circuit is established as follows: earth, armature 701, armature 747 and its resting pad, armature 722, armature 763 and its resting pad, armature spring 773, winding of electro 770, battery, as well as que: armature 722, lower winding of relay 720, battery. As relay 720 is already energized by its upper winding and is delayed release, it does not drop out during the pulse period. The electro 770 attracts and falls with each excitation and de-energization of the relay 700, raising the shaft and the wipers of the connector to the ninth level.

   The 766 Ascension Shaft Contacts are actuated at the first vertical pitch, cutting the

  <Desc / Clms Page number 68>

 circuit from the upper coil of the relay 720 to the armature spring 769, but the relay 720 remains blocked by its lower coil.



   Shortly after receiving the last pulse of the fifth digit, the discriminator selector relay 1240 drops out and closes the transmission circuit from station C to connector at armature 1241. Connector relay 720 drops out at the same time, because its bonding circuit by its lower winding is now cut to armature 701, with attraction of relay 760 by: earth, armature 713, armature spring 772, armature spring 769 and its working pin, armature 724 and its rest pad, upper coil of relay 760, battery; and at armature 722, relay 720 cuts the circuit of the ascension electro 770.

   At armature 765, relay 760 closes a circuit of relay 720 through: earth, armature 713, armature spring 772, armature 765, upper coil of relay 720, battery, and to armature 763, transfers the armature. pulse circuit from the ascension electro 770 to the rotation electro 775. The re-energization of the relay 720 closes a bonding circuit of the relay 760 independently of the shaft contacts of rotation 771 by: earth, armatures 713, 764, armature 724 and its work block, upper coil of relay 760, battery.



   Following formation of the sixth digit (9), the circuit of the disoriminator selector relay 1100 is interrupted nine times. From this moment, the operation of the connector following this last digit (9) is similar to that described for the fourth (last) digit in the chapter "Extension calls coming from the Main Office (Main Posts) to the Post Lines Individuals reporting to this Office (Main Individual Lines) "; it is therefore unnecessary to repeat these details in this chapter. When the called station (501599) answers, the transmission current is supplied to the calling station C by the coils of the line relay

  <Desc / Clms Page number 69>

 
1100 of the discriminator selector, and, at the called station, by the upper and middle windings of the relay 750 of the connector.



   If, at the end of the conversation, both parties have placed their handsets on the respective forks, the call is recorded (before the switches are released) as follows:
The line relay 1100 loop of the discriminator selector is cut when the caller hangs up, and this relay drops To armature 1102, this relay cuts the circuit of relay 1110, but before releasing the latter it goes off. Blows a circuit of relay 1240 through armature 1114 and its working pin. Therefore, relay 1240 attracts and, being delayed release remains attracted for a brief period.

   As soon as relay 1110 drops out, a circuit of relay 1120 is established by: earth, coil of relay 1120, armature 1112 and its rest pad, conductor 1188, armature 1253, wiper 1228, bench pad "+" connected to this slider, conductor 1286, conductor
536, armature 632, slider 617, bench stud "+" connected to this slider, conductor 642, conductor 726, armature 735, armature
744, lower winding of relay 700, armature 754 and its rest pad, resistor 717, battery, with attraction of relay 1120.

   At armature 1121, relay 1120 extends an overvoltage through resistor 1123 and occupancy key 1109 to conductor 1129 going to contactor 1126 of seeker 1108, and from contactor 1126, through conductor 1119, to line circuit 1107 , to activate the counter of station C in a manner similar to that explained for recording the call from station A in the chapter "Calls from Extensions under the Main Office to Individual Extension Lines under this Office". Rectifier 1137 prevents surge current from flowing to earth at armatures 1254 and 1113.

   Releasing relay 1110 also removes the ground of conductor 1129 from finder 1108 to armature 1113, the ground of

  <Desc / Clms Page number 70>

 upper coil of relay 1130 to armature 1113, and the earth of the lower coil of relay 1250 to armature 1115, but the earth is retained on conductor 1129 at armature 1254, on the upper coil of relay 1130 to l armature 1244, and on the lower coil of relay 1250 to armature 1135 and its working pin. Releasing relay 1240 cuts the upper coil circuit from relay 1130 to frame 1244, and relay 1130 drops out after a brief interval.



  At armature 1135, relay 1130 cuts the circuit of the lower coil of relay 1250, with the latter releasing after a brief interval. At armature 1253, relay 1250 cuts circuit 1120 by releasing the latter after a brief interval.



  At armature 1121, relay 1120 removes the overvoltage from the previously indicated circuit of the counter of station C thus freeing this counter. Relays 1240, 1130, 1250 and 1120 are released sufficiently slow to allow the necessary time to recording (counting) the call.



   If the called party does not hang up at the same time as the calling party at extension C, the call count is delayed until the called party hangs up. The fact that the called party does not hang up prevents the connection of the battery through the resistor 717 to the lower winding of the relay 700, because the armature 754 is connected to its working pin and, therefore, the earth is connected by the relay 1120 on the "+" conductor at the connector meets an earth connected by the armatures 711, 755, the armatures 745,754 and their work pads. Under these conditions, relay 1120 cannot attract and counting does not occur.

   However, relay 1240 remains attracted by: earth, armatures 711, 755, armature 745 and its working pin, upper winding of relay 700, conductor 725, conductor 641, bench terminal "-" connected to the wiper 616, wiper 616, armature 631, conductor 535, conductor 1285, bench stud "-" connected to the wiper 1227, wiper 1227,

  <Desc / Clms Page number 71>

 armature 1252, conductor 1181, armature 1111 and its rest pad, armature 1122, conductor 1180, coil of relay 1240, battery. At armature 1242, relay 1240 keeps the discriminator selector release circuit cut off; and, at armature 1244, maintains the blocking circuit of relay 1130. Thus, relay 1130 remains attracted, and the earth by armature 1135 and its working pin keeps relay 1250 blocked.

   At the armature 1258 and its working pin, the relay maintains the earth, of the armature 1135 and its working pin, on the wiper 1229, to keep the second selector actuated. Following the hang-up by the interlocutor of the requested station, the connector relay 750 drops, and the battery is connected to the lower coil of the relay 700 by the resistor 717 and the armature 754 and its rest pad.



  Therefore, relay 1120 attracts and counting is carried out as described in the previous paragraph.



   After the call has been counted, the switches are released as follows:
The discriminator selector 1100 line relay loop circuit is cut when the caller at station C hangs up and relay 1100 drops out. At armature 1102, this relay cuts the circuit of relay 1110, but before the latter drops out, a momentary circuit of relay 1240 is established by armature 1114 with attraction of this relay. After a brief interval, relay 1110 drops out, and then relay 1240.



  At armature 1113, relay 1110 removes the earth of conductor 1129 to free searcher 1108 and the cutting relay of calling station C as explained in the chapter "Calls from Posts under the Main Office to Individual Post Lines falling under this Office ". When releasing in connection with the call count, relay 1130 removed a ground from the blocking circuit of relay 1250, and when releasing relay 1110 the remaining earth was removed from the block circuit.

  <Desc / Clms Page number 72>

 blocking circuit of relay 1250, with release of the latter. Releasing relay 1130 also removed earth from wiper 1229, to free the second selector.



  The circuit of the release electro 1275 of the dis "criminal selector is now closed by: earth, armatures 1242, 1259, 1217, conductor 1203, armature 1134 and its rest pad, conductor 1199, armature spring 1246, winding of electro 1275, battery The energization of the electro 1275 causes the release of the discrimination selector according to the known Strowger system, and the armature 1277 of this electro keeps the circuit of the wiper 1229 cut off during the release of this electro. Selector Switch The circuit of the electro 1275 is cut by the armature spring 1246 of the ascension shaft contacts 1245 when the switch shaft reaches its home position.

   The second selector (fig. 6) and the connector (fig. 7) are released in the general manner described in the chapter "Calls from Extensions under the Main Office to Individual Line Positions under this Office" concerning the case where the caller at set A drops the call. There is therefore no need to repeat these details in this chapter.



   Although the communication described in this chapter uses the connector according to fig. 7, it should be noted that the connector for multiple PBX line subscribers, shown in fig. 8 and described in the chapter "Extension calls coming from the Main Office (Main Stations) to Private Central Subscriber Lines (PBX) coming from this Office" can just as well be used instead of the connector of fig. 7.



   Calls from the Satellite Office (Branch Office) to the Main Office.



   To describe a call from a local extension of a satellite office to a main extension, assume that extension C (fig. 11) calls a main extension. We will further assume

  <Desc / Clms Page number 73>

 that the wipers 1124, 1125 and 1126 of the searcher 1108 found the line circuit 1107 of the station C and connected to this circuit in a manner similar to that described in the chapter "Calls from Extensions under the Main Office to Post Lines Individuals reporting to this Office ". It will further be assumed that the rubbers 1237, 1238 and 1239 of the outgoing junction finder (fig. 12) rest on a junction going to a free outgoing junction circuit according to Fig. 13, and that the latter circuit is connected directly to a first incoming selector from the main office according to fig. 14.



   In the case indicated in the previous paragraph, the line relay 1100 of the discriminator selector is kept drawn on the calling loop circuit of station C, and the relay 1330 of the outgoing junction circuit is kept drawn on the loop circuit by: earth, frame 1422 and its rest stud, frame 1412 and its rest stud, frame 1435, frame spring 1427 and its rest stud, conductor 1303, frame 1311 and its rest stud, resistor 1315, frame 1342, rest stud armature 1321, armature rest pad 1343, upper coil of relay 1330, armature rest pad 1341, conductor 1300, upper coil of relay 1400, armature spring 1426 and its rest pad, lower winding of relay 1400, battery.

   The high resistance of the top winding of relay 1330 prevents operation of relay 1400 in the circuit just shown. Resistor 1315 is provided in the "+" side of the junction circuit, so that the resistance of this circuit can be adjusted to the desired value. At armature 1102, relay 1100 closes an obvious circuit of relay 1110, with the attraction of the latter.

   To armature 1113, relay 1110 connects the earth potential to conductor 1129 by: conductor 1190, armatures 1215, 1255, conductor 1189, rectifier 1137 and occupancy key 1109, to keep searcher 1108 and the switching relay energized.

  <Desc / Clms Page number 74>

 line circuit 1107, Relay 1110 also closes an air-cured of relay 1230 by: earth, armature 1115, conductor 1200, armature 1257 and its resting pin, armature spring 1247 and its resting pin, lower coil of the relay 1230, battery, by drawing relay 1230.

   At armature 1235, relay 1230 closes a circuit of relay 1210 by: earth, armature 1135 and its rest pad, conductor 1205, armature 1235, upper coil of relay 1210, wiper 1239, bench pad connected to wiper 1239, conductor 1302, armature 1345 and its rest pad, upper coil of relay 1310, armature 1321 and its rest pad, lower coil of relay 1330, battery.



  The circuit of the upper coil of relay 1310 and of the lower coil of relay 1330 to the battery is multiplied with respect to the latter through resistor 1329 and armature 1322 in order to provide the wiper 1239 with the eigenvalue for the selective search of drums. The relays 1210 and 1310 attract in the circuit which has just been indicated the relay 1330 having been previously attracted in the circuit indicated in the first part of this paragraph. The operation of relay 1310 in the outgoing junction circuit causes this circuit to be entered by the discrimination selector as described in the previous paragraph.

   At armature 1311, relay 1310 cuts the circuit of the upper winding of relay 1330, but the latter sticks in the circuit passing through its lower winding; àl'armature 1311 and its working pad, the relay 1310 connects the conductor 1301 to the conductor 1303 of the first incoming selector; at armature 1312, it closes an obvious circuit for supervisory lamp 1306; at armature 1313, it removes the earth of conductor 1304 of the common relay "all junctions occupied"; and to reinforcement 1313, connects the earth to conductor 1305 of the communication counter (not shown) by: earth, reinforcement 1313 and its working stud, reinforcement 1327 and its resting stud, reinforcement 1314,

  <Desc / Clms Page number 75>

 conductor 1305.

   At armature 1218, relay 1210 closes a blocking circuit for its lower winding by: earth, armature 1115, resting pad for armature 1172, armatures 1156, 1167, conductor 1206, armature 1218 and its working block, winding lower of relay 1210, battery. In frame 1219, relay 1210 connects "direct earth" to wiper 1239 as a busy guard, as well as to hold back the seized outgoing trunk circuit. At armature 1216, relay 1210 closes a circuit of relay 1130 by: earth, armature 1113 and its working pin, conductor 1190, armature 1216, conductor 1191, upper coil of relay 1130, battery, so that the relay 1130 attracts and is blocked to the ground by the armature 1113 and its working pin, and the armature 1132.



  At armatures 1212 and 1213, relay 1210 extends the transmission circuit of calling station C to the outgoing junction circuit seized by wipers 1237 and 1238. At armature 1131, relay 1130 sends the transmission signal back to l 'calling by: armature 1131 and its working block, resting block of the armature 1141, conductor 1185, armature 1232 and its working block, conductor 1184, lower coil of relay 1100, conductor 1128, wiper 1125, conductor 1118, line circuit 1107, listening circuit of station C.



   We will temporarily depart from the description of a call initiated at station C, to explain how an outgoing junction finder (fig. 12) searches for a junction going to a free outgoing junction circuit, for example like that of fig. 13. If, the outgoing junction finder brushes 1237, 1238, and 1239 are not stopped on a junction going to a free outgoing junction circuit, relay 1210 cannot attract when relay 1230 attracts, because the ground potential is connected to the wiper 1239 by the conductor 1302 of the busy outgoing junction circuit,.



  On the other hand, relay 1230 closes a circuit of electro 1270

  <Desc / Clms Page number 76>

 of the outgoing junction finder by: earth, reinforcement 1115, resting stud of reinforcement 1172, reinforcement 1156, 1167, conductor 1206, reinforcement 1218 and its resting stud, reinforcement 1222, conductor 1208, reinforcement 1136 and its stud rest, conductor 1207, armature 1236, electro coil 1270, battery.



  Electro 1270 attracts, places its pawl in a position preparatory to the advancement of wipers 1237, 1238 and 1239 by one step, and closes a circuit of relay 1220 by: earth, armature 1135 and its rest pad, conductor 1205 , armature 1235, breaking or breaking armatures 1271, 1266, winding of relay 1220, battery with excitation of relay 1220. At armature 1222, relay 1220 cuts the circuit of electro 1270, so that the latter releases and advance the wipers 1237, 1238 and 1239 one step towards the bench pads of the next junction. At the rupture armature 1271, the electro 1270 cuts the circuit of the relay 1220, releasing the latter.



  If the outgoing junction circuit connected to these bank pads is free, a battery potential is connected by the conductor 1302 of the free outgoing junction circuit to the upper coil of the relay 1210 through the wiper 1239, so that this relay attracts and locks in the manner previously indicated in this chapter.



  The circuit of electro 1270 is now cut at armature 1136 and no rotation of trotters 1237, 1238 and 1239 can be made.



   If the outgoing junction circuit connected to the bench pads on which the wipers 1237, 1238 and 1239 arrived by rotation, according to the preceding paragraph, is occupied, the relay 1210 cannot attract and the relay 1130 remains in its normal position. The circuit of the electro 1270 is therefore closed at the armature 1222 following the release of the relay 1220 after the first energization of the electro 1270, and the latter attracts again, brings its oliquet into a prepared position.

  <Desc / Clms Page number 77>

 to the advancement of the wipers 1237, 1238 and 1239 by another step, and closes the circuit of the relay 1220 to the rupture armature 1271. The relay 1229 again attracts and cuts the circuit of the electro 1270 to the armature 1222, so that this electro falls by advancing the wipers 1237, 1238 and 1239 of a new step.

   This interaction of electro 1270 and relay 1220 continues until wiper 1239 encounters a battery potential returned to conductor 1302 of a selected free outgoing junction circuit. When all outgoing junction circuits connected to the outgoing junction finder banks are busy, the common "all junction busy" relay 1280 drops out, because there is no earth potential on the common conductor 1304.



  At armature 1281, relay 1280 applies a interrupted signal at about sixty pulses per minute to the lower coil of relay 1130 by armature 1233, so that relay 1130 attracts and blocks by its upper coil within a second. the occupation of the discriminator selector. At armature 1136, relay 1130 cuts off the circuit of electro 1270, so that the latter releases and advances the wipers 1237, 1238, and 1239 a further step. However, the control circuit of the relay 1210 cannot close, since all the outgoing trunk circuits are busy and, therefore, the transmission circuit of the discriminator selector is not extended to the armatures 1212 and 1213. The station Caller then receives a dial signal and the caller can start dialing.

   If the call is intended for a set in the same (local) office, communication is established as described in the chapter "Local calls to the Satellite Office". If the call is to a main office (correspondent) extension, the busy signal will be returned to the calling extension after the call has been identified as local. In the latter case, the busy signal circuit can be established as follows:

  <Desc / Clms Page number 78>

 busy signal socket at armature 1161, conductor 1186, armature 1211, armature spring 1248 and capacitor 1105 at the "+" side of the transmission circuit.



   We will now come back to the description of the call from set C to a main set. Assume that the latter's call number is 53999, and that in the discriminator selector, the discrimination between a local number and a main office number occurs after the second digit.



  In this case, the right rest shaft contact 1147 is set to make contact when the shaft of this switch reaches the fifth level (the first digit of the main office call number or main number being 5). The left rest shaft contact 1148 is set to make contact when the switch shaft reaches the tenth level or floor as explained in the "Local Calls to Satellite Office" chapter.



   On perceiving the well-known switching signal, the caller to station C transmits the number 53999. Following the sending of the first digit (5), the discriminator selector shaft is raised to the fifth level and is then automatically released. as described in the chapter "Local calls to the satellite office" about sending the first digit (5) of a local number to the satellite office. During the pulses of the first digit, the relay 1100 of the discriminator selector also sends corresponding pulses to the relay 1400 of the first incoming selector, through the circuit: earth, armature 1101, armature 1111 and its working pin, conductor 1181, armature 1212, wiper 1237, driver 1300, so relay 1400 of the first incoming selector pulls in and drops out five times.



  The circuit of the first pulse is closed by: upper winding of relay 1400, armature spring 1426 and its resting pin, lower winding of relay 1400, battery and, for the four remaining pulses, by: upper winding of

  <Desc / Clms Page number 79>

 relay 1400, armature 1421 (relay 1420 being attracted during the first pulse), lower winding of relay 1400, battery. At armature 1401, relay 1400 transmits an impulse to electro-ascension 1440 and relay 1420 in parallel, each time the line relay 1100 of the discriminator selector is de-energized.

   The multiplied circuit of electro 1440 and relay 1420 for the first pulse can be established as follows: earth, armature 1401, resting pad of armature 1423, armature 1414 and its resting pad, winding of electro 1440 , battery, as well as: earth, armature 1401, rest pad for armature 1423, armature 1414 and its rest pad, coil of relay 1420, battery. The multiplied circuit of electro 1440 and relay 1420 for the four remaining pulses is closed by: earth, armature 1401, armature 1423 and its working pin, electro winding 1440, battery, as well as: earth, armature 1401 , armature 1423 and its working pad, coil of relay 1420, battery, relay 1420 being attracted by the first pulse, and the others for the duration of the following pulses.

   At armature 1421, relay 1420 directly connects the upper and lower windings of relay 1400 in series to establish a circuit for that relay after the ascension shaft contact 1425 has been actuated by the elevation of the switch shaft.



  Electro 1440 pulls in and drops with each excitation and de-energization of relay 1400, raising the shaft and trotters to the fifth level and actuating the ascent shaft contact 1425 with the first vertical step.



   Closing of relay 1420 also closes a circuit via: earth, armature 1422 and its working contact, lower winding of relay 1460, lower winding of relay 1410, battery, with energization of relays 1460 and 1410. To armature 1462 , relay 1460 closes a bonding circuit for relay 1410 and for itself, independently of relay 1420 by:

  <Desc / Clms Page number 80>

 earth, armature 1462, upper coil of relay 1410, lower coil of relay 1460, lower coil of relay 1410, battery. With the armatures 1412 and 1414, the relay 1410 prepares a circuit of the lower winding of the relay 1400 and a circuit of the electro rotation 1450.



   After the ceasing of the pulses coming from the line relay 1100 of the discriminator selector, the relay 1400 of the first incoming selector drops out and cuts the blocking circuit from the relay 1420 to the armature 1401, with the release of the relay 1420 after a brief interval. At armature 1423, relay 1420 cuts the circuit of vertical electro 1440, at armature 1421 it disconnects the lower coil of relay 1400 from the upper coil of this relay; at armature 1422 it closes a circuit of the lower winding of relay 1400 on the ground, armature 1422 and its rest stud, armature 1412 and its working pin, armature 1434 and its rest pin, armatures 1451, 1463, spring armature 1426 and its working pin, lower winding of relay 1400, battery, with excitation of relay 1400.

   At armature 1401, relay 1400 closes the circuit of rotary electro 1450 by: earth, armature 1401, resting pad of armature 1423, armature 1414 and its working contact, electro coil 1450, battery.



  The electro 1450 attracts and rotates the shaft and the wipers of the first entering or arriving selector by one step in the bank level chosen by the ascent pulse (fifth level). Rotation shaft contact 1405 works with the first rotary step of the switch shaft, connecting the battery potential through resistor 1406 to breakout pin 1451 of electro 1450 in parallel with the lower coil of relay 1400 in order to reduce the bursting of sparks at the breaking contact 1451 during rotation. The actuation of the electro 1450 also has the effect of interrupting the circuit of relay 1400 at the disconnecting armature 1451,

  <Desc / Clms Page number 81>

 so that this relay drops out and cuts the circuit from electro 1450 to armature 1401. This electro drops in turn and closes the circuit of relay 1400.

   At this time, it works. The first incoming selector depends on whether the second selector connected to the first set of bank pads of the fifth level is occupied or free.



   If the second selector is free, the slider 1418 of the first incoming selector finds a battery potential supplied by the second selector on pin C of the first set of bank pads, and a circuit closes for the relay 1430 of the first. selector entering via: earth, armature 1413, lower coil of relay 1430, wiper 1418, bench pad C connected to wiper 1418, conductor 1443, battery (supplied to this bench pad by the second selector), so that relay 1430 attracts and prevents subsequent rotational pulses from the first incoming or outgoing selector, by cutting the circuit from relay 1400 to armature 1434.

   If the second selector is busy, the slider 1418 of the first incoming selector meets the ground potential on the pin C of the first set of bank pads, so that the relay 1430 of the first incoming selector cannot attract. The relay circuit 1400 is therefore maintained at the armature 1434 and its rest pad, so that the relay 1400 again attracts and closes the circuit of the electro 1450. The latter attracts again, advances the shaft and them. switch wipers a second rotation step, and again cuts the relay circuit 1400.

   This reciprocal action between the electro 1450 and the relay 1400 continues until the slider 1418 encounters a battery potential on the pin C of a set of bench pads connected to a second free selector, or until that the rubbers 1416, 1417 and 1418 are advanced to the eleventh position of the benches. In the latter case, cam contact 1445 is actuated and the busy signal is sent to the caller at

  <Desc / Clms Page number 82>

 station C by the armature spring 1447 at the "+" side of the transmission circuit.

   Actuation of the cam contact 1445 also has the effect of closing a circuit of relay 1430 by: earth, armature 1413, lower coil of relay 1430, armature 1436 and its resting pin, armature spring 1446, resistance 1448, battery, so that the relay 1430 attracts and blocks by: earth, armature 1422 and its resting pin, armature 1412 and its working post, armature 1434 and its working pin, upper winding of relay 1430, winding of electro rotation 1450, battery. The high resistance of the top coil of relay 1430 prevents electro 1450 from operating in the circuit of this coil.

   At armature 1434, relay 1430 cuts the circuit of the lower winding of relay 1400; therefore, the control circuit of the rotation electro 1450 remains cut off at the armature 1401, thus preventing the subsequent rotation of the shaft and of the rubbers of the first incoming selector.



   It will now be assumed that the second selector shown in FIG. 6, is housed in the main office, is free and was chosen by the first incoming selector in fig. 14.



  In this case, the relay 1430 of the first incoming selector is attracted by its lower winding as described in the first part of the previous paragraph. At armature 1434, relay 1430 closes a blocking circuit of its upper winding by: earth, armature 1422 and its resting pin, armature 1412 and its working pin, armature 1434 and its working pin, upper coil of the relay 1430, coil of electro 1450, battery, the high resistance of the upper coil of relay 1430 preventing actuation of electro 1450; to armature 1436 and its working pin, relay 1430 connects the continuous signal "direct ground" to the contactor 1418 as an occupancy guard, as well as to close the circuit of the upper coil of the relay 620 of the second selector;

   to the armature 1457, it connects the earth to the conductor 1403 of the comp-

  <Desc / Clms Page number 83>

 communications tor (not shown); and, at frames 1431 and 1432, extends the transmission circuit from station C to the second selected selector.



   Following the sending of the second digit (3) the circuit of relay 1100 is interrupted three times, and the pulses are transmitted accordingly to the electro 1260, to the relay 1240 and to the upper coil of the relay 1230 from earth and the rest contact of the armature 1103. The relays 1240 and 1230 do not drop during the pulses. The electro 1260 attracts and falls with each impulse raising the shaft and the sliders of the discrimination selector to the third level of the bench blocks as described in the chapter "Local Calls to the Satellite Office" about sending. the third digit (1) of a local number for that office.



   Shortly after receiving the last pulse of the second digit (3), relays 1240 and 1230 drop out. At armature 1231, relay 1230 cuts the circuit of its upper winding and of the vertical electro 1260. At the rest contact of armature 1232, relay 1230 maintains the continuous signal (direct earth) on the lower winding of the relay 1100. However, in this case, releasing relay 1230 cannot cause relay 1160 to actuate, because the circuit of the latter's windings is cut at armature 1152. Therefore, relay 1220 cannot attract to this moment, because its circuit is cut at contact 1166, and the circuit of the rotation electro 1265 is therefore cut at the armatures 1221 and 1162.

   The rubbers of the discriminator selector are therefore maintained at the level of the third stage of the discriminator selector blocks and cannot rotate in this level, since the circuit of the rotation electro 1265 cannot be closed.



   During the pulses of the third digit (3), the relay 1100 of the discriminator selector also transmits corresponding pulses to the relay 600 of the second selector via: earth,

  <Desc / Clms Page number 84>

 armature 1101, armature 1111 and its work stud, conductor 1181, armature 1212, wiper 1237, conductor 1300, (fig. 13 - fig. 14), armature 1431, wiper 1416, bench stud connected to wiper 1416, conductor 1441 connected at the aforementioned bench block, conductor 535 (fig. 6), lower coil of relay 600, armature 621 and its working block, upper coil of relay 600, battery. The line relay 600 of the second selector attracts and therefore falls on each de-energization and re-energization of the line relay 1100 of the discriminating selector.

   From this point, the operation continues as described in the chapter "Calls from Main Extensions to Individual Main Extension Lines", and it is therefore unnecessary to repeat these details in this chapter.



   It will now be assumed that the third selector designated by 780 in FIG. 7, has the same circuit details as the second selector according to fig. 6, is housed in the main office, is free, and was chosen by the second selector in fig. 6. In this case, the relay 630 of the second selector is attracted by: earth, armature 613 and its working pad, lower coil of relay 630, wiper 618, bench pad C connected to wiper 618, conductor 643, battery potential supplied by the third selector 780 on conductor 643.

   At armature 633, relay 630 closes a blocking circuit for its upper winding by: earth, armature 1436, wiper 1418, stud of bench C connected to wiper 1418, conductor 1443, conductor 537 (fig. 6), armature 633 and its working pad, upper coil of relay 630, coil of rotation electro 650, battery, the high resistance of the upper coil of relay 630 preventing operation of electro 650; at armature 634, relay 630 cuts the circuit of the upper winding of relay 600, thus preventing the operation of this relay; to armature 633, it cuts the circuit of relay 610, releasing

  <Desc / Clms Page number 85>

 thus the latter; to the frame 636 and its working block, it connects the "direct earth" to the wiper 618 as an occupancy guard, as well as to glue the third seized selector 780;

   to armature 637, it connects a "multiple earth" to conductor 603 of the conversation counter; and, at reinforcements 631 and 632, extends the transmission circuit from station C to the third selector 780. Following the sending of the third digit (9) the circuit of relay 1100 of the discriminator selector is cut nine times, and pulses are transmitted accordingly to relay 1240 via earth and the resting pad of armature 1102. Relay 1240 attracts with the first pulse and, at armature 1241, cuts off the transmission circuit to the second and third selectors. .

   At armature 1101, relay 1100 transmits a pulse to the line relay of the third selector 780 (the line relay of the third selector 780 being analogous to the line relay 600 of fig. 6) on each de-energization, by: earth, armature 1101, armature 1111 and its working stud, conductor 1181, armature 1212, wiper 1237, conductor 1300 (fig. 13 - fig. 14), armature 1431, wiper 1416, bench stud connected to the wiper 1416, conductor 1441 connected to this bench block, conductor 535 (fig.

   6) of the second selector, armature 631, wiper 616, bench stud connected to wiper 616, conductor 641 going to the third selector 780, windings of the line relay of the third selector 780, battery (the line relay of the third selector n This is not shown, being analogous to the line relay 600 of the second selector (Fig. 6) So the line relay of the third selector 780 pulls in and drops out on each de-energization and re-energization of the line relay 1100 of the discriminator selector.

   From this moment, the description of the operation of the third selector 780 is the same as that which appears in the chapter "Calls from Main Extensions to Individual Main Extension Lines" regarding the second

  <Desc / Clms Page number 86>

 selector, with this general difference that the third selector 780 is driven by the pulses to the ninth level of its blocks of pads by sending the third digit (9).



   It will now be assumed that the connector according to fig. 7 is housed at the main office, is free and has been chosen by the third selector 780. In this case, the operation of this connector following the sending of the fourth digit (9) and the fifth digit (9) is analogous to that described with regard to the third and fourth digits in the chapter "Calls from Main Extensions to Individual Main Extension Lines"; it is therefore unnecessary to repeat these details in this chapter. When the called station (53999) answers, the transmit current is supplied to the calling station C through the winding of the line relay 1100 of the discriminator selector and, to the called station through the upper and middle windings of the relay 750 of the connector. .



   It will then be assumed that the conversation has been ended, that both parties have hung up and that the recording (counting) of the call has taken place in a manner analogous to that explained in the chapter "Local calls to the Satellite Office ( Branch Office) ". In this case, the switches are released as follows: the discriminator selector switch 1100 line relay loop circuit is cut when requestor C hangs up, and relay 1100 drops out by cutting the circuit from relay 1110 to armature 1102. Afterwards a brief interval, the relay 1110 drops out and, at the armature 1113, eliminates the earth of the conductor 1129 to free the searcher 1108 and the cut-off relay of the calling station C in a manner analogous to that explained in the chapter "Station calls Main to Individual Main Post Lines ".

   At the moment when the relay 1130 has triggered in relation to the count of the commu ..

  <Desc / Clms Page number 87>

 This relay removed a ground from the blocking circuit of relay 1250 and, when relay 1110 de-energized, the remaining ground was removed from the blocking circuit of relay 1250, releasing the relay. Releasing relays 1130 and 1110 eliminated "multiple grounds" from the blocking circuit of relay 1210, so that the latter tripped and removed the earth from wiper 1239 to free the outgoing junction circuit (fig. . 13) seized.



  The circuit of the electro-release 1275 of the discriminator selector is now closed by: earth, armatures 1242, 1259, 1217, conductor 1203, armature 1134 and its rest stud, conductor 1199, armature spring 1246 and its stud working, coil of electro 1275, battery, Operation of electro 1275 releases the shaft and the wipers of the discriminator selector, and the circuit of this electro is cut by the armature spring 1246 of the contact d 1245 ascension shaft when the shaft of this switch reaches its normal position.



   The elimination of the earth potential of the wiper 1239, described in the previous paragraph, cuts the circuit of the upper winding of relay 1310 and of the lower winding of relay 1330 of the outgoing junction circuit of fig, 13, Relay 1330 drops out immediately, closing a circuit of the upper winding of relay 1320 through: earth, armature 1331, lower winding of relay 1310, upper winding of relay 1320, battery. Relay 1320 attracts and closes a blocking circuit for its upper winding from earth through armatures 1331 and 1323. At armature 1323, relay 1320 short-circuits the lower coil of relay 1310, and the latter drops out after a brief interval.

   However, before tripping, of relay 1310, relay 1320 closed a circuit of the primary winding of transformer 1335 by: earth, armature 1313 and its working pin, armature 1327 and

  <Desc / Clms Page number 88>

 its work pad, resistor 1332, primary winding of transformer 1335, battery. Therefore, a high voltage is induced in the secondary winding of this transformer and is transmitted through the "+" side of the transmission circuit through the armature 1325 and the armature 1311 and its working stud, to the conductor 1303. of the first incoming or outgoing selector (fig. 14), in order to release it in the manner described in the last paragraph of this chapter. On the other hand, at armature 1327, relay 1320 removes the ground potential of conductor 1305 of the communications counter.

   Releasing relay 1310 cuts the circuit from the primary winding of transformer 1335 to armature 1313, thereby eliminating the high voltage potential on the "+" side of the transmission circuit. At armature 1312, relay 1310 eliminates direct earth from supervision lamp 1306; to armature 1313, it connects the earth to supervision lamp 1306 by means of armature 1313 and its resting post, armature 1326 and its working post, and resistor 1316 , so that this lamp gives a dim light (instead of a clear light), which indicates that the previous switch (discriminator selector) has tripped; at armature 1311, it disconnects conductor 1301 from conductor 1303 of the first incoming selector;

   and, to the armature 1311 and its rest pad, again connects the upper coil of the relay 1330 in series with the resistor 1315 in shunt on the conductors 1300 and 1303 of the first incoming selector.



   The momentary high voltage potential received on conductor 1303 from the first incoming selector (before relay 1310 drops out and opens the make contact of armature 1311) is conducted through armature 1411 and resistor. 1465 (shunted by capacitor 1466) to gas-filled tube 1464, the other terminal of which is connected to earth.

   The high voltage potential immediately "snaps" the high resistance

  <Desc / Clms Page number 89>

 gas in tube 1464 in the manner well known in electronic phenomena, thus causing a momentary flow of direct current from the battery through: secondary winding of transformer 1335, armature 1325, armature 1311 and its working stud, conductor 1303, armature 1461, upper coil of relay 1460 to earth, through the now reduced internal resistance of tube 1464, before this high voltage potential has been dissipated and this resistance has returned to its normal high value.

   The upper and lower windings of relay 1460 are wound in opposite directions; therefore, the momentary flow of DC current through the upper coil neutralizes the direct current flow through the lower coil, and this relay drops out.



  At armature 1462, this relay cuts off current flow through its lower coil and the coils of relay 1410, thus maintaining itself at rest and causing relay 1410 to trip after a brief interval. At armature 1412, relay 1410 cuts the blocking circuit of the upper winding of relay 1430, which drops out. At armature 1436, relay 1430 eliminates the earth of the wiper 1418 to free the second selector; at reinforcements 1431 and 1432, it cuts the transmission circuit of the second selector; and, at armature 1435, closes the circuit of the release electro 1405 by: earth, armature 1422 and its rest pad, armature 1412 and its rest pad, armature 1435, armature spring 1427 and its working pad, winding of the Eleotro 1405, battery.



  The energization of the electro 1405 causes the release of the first incoming selector according to the known Strowger system, and the circuit of the electro 1405 is cut by the armature spring 1427 when the switch shaft reaches its normal position. . Releasing relays 1410 and 1460 disconnects tube 1464 from the "+" side of the transmission circuit to armatures 1411 and 1461.

  <Desc / Clms Page number 90>

 



   In the event that the high voltage potential transmitted on the "+" side of the transmission circuit to the first incoming selector as described in the previous paragraph failed to release that selector, a momentary additional high voltage potential would be transmitted on this same side. of said circuit in the manner described in this paragraph. The moment relay 1320 pulled in and blocked, it closed the starting circuit for a periodic signal transmitter (timer) 1350 to armature 1328. This transmitter applies an earth pulse through: "PU" conductor , lower winding of relay 1320, armature 1324, resting pad of armature 1346, coil of relay 1340, battery, so that relay 1340 attracts and locks to earth by the "BOND" conductor from said transmitter and working block of the armature 1346.

   At armature 1344, relay 1340 connects earth to conductor 1302, to indicate to all other calls that the outgoing trunk circuit is busy; and, to frame 1347, connects a "multiple earth" to the "START" conductor of said transmitter. A subsequent earth pulse on the 1 "PULSE conductor coming from the transmitter closes a circuit of the upper winding of relay 1330 by armature 1343 and its working pin, the upper coil of relay 1330, armature 1341 and its working stud, resistor 1348, battery, so that the relay 1330 attracts and cuts the blocking circuit of the relay 1320 to the armature 1331. The relay 1320 drops out.

   An earth pulse on the "IMPUISION 2" conductor coming from the transmitter closes a circuit of the upper winding of relay 1310 by: armature 1345 and its working pin, upper coil of relay 1310, resting pin of armature 1321, lower winding of relay 1330, battery, so that relay 1310 attracts. of the latter attracted previously in the circuit comprising its upper winding and the earth pulse of the conductor "IMPUISION 1".

  <Desc / Clms Page number 91>

 



  At the end of the first cycle of the duration counter or periodic pulse generator (timer) 1350, the earth is eliminated from the "PU", "BOND" ', "PULSE 1" and "IMPUISION 2" conductors, and the related circuits relays 1320, 1340, 1330 and 1310 are cut. Relays 1330, 1320 and 1340 drop immediately, but relay 1310 remains energized for a short time, being delayed release. Releasing relay 1330 closes a circuit of the upper coil of relay 1320 through the lower coil of relay 1310, so that relay 1320 again attracts and locks by its armature 1323 before releasing relay 1310.

   Therefore, a second high voltage momentary potential is applied to the "+" side of the transmission circuit as described in the previous paragraph for the first high voltage momentary potential. In the event that the first incoming selector is not released as a result of the second momentary high voltage potential applied to the "+" side of the transmission circuit, the duration counter (timer) 1350 performs one or more additional cycles, up to release of the first incoming selector. The duration counter is common to several outgoing trunk circuits and starts each time the "START" conductor is earthed.



   Releasing the first incoming selector (fig. 14) closes a circuit of the upper winding of relay 1330 of the outgoing junction circuit by: earth, armature 1422 and its resting stud, armature 1412 and its resting pin, armature 1435, spring of 'armature 1427 and its rest pad, conductor 1303, armature 1311 and its rest pad, resistor 1315, armature 1342, armature rest pad 1321, armature rest pad 1343, upper coil of relay 1330, armature rest pad 1341, conductor 1300, upper coil of relay 1400, armature spring 1426 and its rest pad, lower coil of relay 1400, battery, resistor

  <Desc / Clms Page number 92>

 high winding of the upper winding of relay 1330 preventing operation of relay 1400, To armature 1331,

   relay 1330 cuts the blocking circuit of the upper winding of relay 1320, releasing the latter. The circuits of the supervision lamp 1306 are cut at armatures 1312 and 1326, and the extinction of this lamp indicates that the outgoing junction circuit (fig. 13) and the first incoming selector associated with it (fig. 14) are released.



   The second selector (fig. 6) of the third selector 780 and the connector (fig. 7) is released in a manner similar to that described in the chapter "Calls from Main Extensions to Individual Main Extension Lines" regarding releasing the second selector (fig. 6) and the connector (fig. 7) after a local call to the main office.



   Although the communication described in this chapter uses the connector according to fig. 7, it should be noted that the PBX connector selcn fig, 8 described in the chapter "Calls from Main Extensions to Main PBX Lines" can be used instead of the connector according to fig. 7 described in this chapter.



   Calls from the Main Office to the Satellite Office (Branch Office).



   To describe a call from a local extension in the main office to a station in the satellite office, assume that station A (Fig. 1-A) calls a station in the satellite office. It will also be assumed that the rubbers 261, 263 and 265 of the finder of FIG. 2 found the line circuit 100 of station A, on which they stopped, in the manner described in the chapter "Calls from Main Stations to Individual Main Station Lines". It will also be assumed that a set of bench pads from the fifth level of the first local selector in fig.



  5, from the main office, is connected to conductors 535, 536 and 537 of the second local selector (fig. 6) of the main office;

  <Desc / Clms Page number 93>

 that a set of tenth level bench studs from the second local selector (fig. 6) of the main office is connected to leads 1300, 1301 and 1302 of the outgoing trunk circuit (fig. 13) of the main office; that the conductors 1300 and 1303 of this outgoing junction circuit are connected directly to the third incoming selector (fig. 14) of the satellite office; that a set of bench pads of the first level of the third incoming selector (fig. 14) of the satellite office is connected to conductors 641, 642 and 643 of the fourth local selector 780 (fig. 7) of the satellite office;

   and, that a set of fifth level bench pads (not shown) of the fourth local selector 780 of the satellite office is connected to the conductors 725, 726 and 727 of the connector (Fig. 7) of the satellite office.



   Under the conditions indicated in the previous paragraph, the line relay 500 of the first local selector (fig. 5) is kept attracted to the calling loop of station A, and an operating signal is sent to the calling party by: spring rest pad 517 of the elevator shaft contact. sion 524, conductor 634, lower coil of relay 500, conductor 271, armature 222, trotter 263, bench block "+" associated with calling station A, listening circuit for station A Having perceived the well-known switching signal, The caller dials the number of the requested extension of the satellite office, assumed to be 501599.

   Following the formation of the first number (5) the shaft and the wipers of the first local selector (fig. 5) are raised to the fifth level and brought to place on the set of bench studs connected to the conductors 535, 536 and 537 of the second local selector (fig. 6) as described in detail in the chapter "Calls from Main Extensions to Individual Main Extension Lines".



   Following the sending of the second digit (0) the shaft and the wipers of the second local selector (fig. 6) rise

  <Desc / Clms Page number 94>

 up to the tenth level and are placed on the set of bench studs connected to the conductors 1300, 1301 and 1302 of the outgoing junction circuit (fig. 13) as described in the chapter "Calls from Main Stations to Individual Main Substation Lines "about the operation of the second selector.



  An earth potential by: 613 and its working contact, lower winding of relay 630, wiper 618, conductor 1302 of the outgoing junction circuit (fig. 13), armature 1345 and its rest contact, upper coil of relay 1310, armature 1321 and its rest pad, lower coil of relay 1330 and battery, causes relay 1310 to operate, relay 1330 being normally attracted. The activation of relay 1310 has the effect of seizing the outgoing junction circuit by the second local selector in a manner analogous to that described in the third paragraph of the chapter "Calls from the Satellite Office to the Main Office".



   Following the sending of the third digit (1) the shaft and the wipers of the third incoming selector (fig. 14) are raised to the first level and brought to the set of bench studs connected to the conductors 641, 642 and 643 of the fourth local selector 780 (fig. 7) in a manner similar to that described in the chapter "Calls from the Satellite Office to the Main Office" regarding the actuation of the first incoming selector.



   Following the sending of the fourth digit (5) the shaft and the wipers (not shown) of the fourth local selector 780 are raised to the fifth level (not shown) and brought to the set of bench studs connected to conductors 725,726 and 727 of the connector (fig. 7) in a manner similar to that described in the chapter "Calls from Main Extensions to Individual Main Extension Lines" about the operation of the second local selector.

  <Desc / Clms Page number 95>

 



   Following the sending of the fifth and sixth digits (9 and 9), the connector (fig. 7) is made to choose the line circuit of the station of the satellite office, corresponding to the number 501599 in a manner analogous to that described. for the third and fourth digits in the chapter "Calls from Main Extensions to Individual Main Extension Lines". When the called station answers, transmit current is sent to the main calling station A through the coils of the relay 500 of the first local selector and, to the called station of the satellite office, through the upper and middle coils of the connector relay 750.



   It will now be assumed that the conversation has been terminated, that the caller at the main set A and the called party in the satellite office have both hung up, and that the call count has been carried out as explained in the "Calls from" chapter. Main Posts to Individual Main Post Lines ". In this case, the switches are released as follows: the first local selector, the researcher associated with it, the line circuit 100 of calling station A and the second local selector at the main office are released as described in the next chapter. to be cited. The outgoing trunk circuit (fig. 13) of the main office and the third incoming selector (fig. 14) of the satellite office are released as described in the chapter "Calls from the Satellite Office to the Main Office".

   The fourth local selector, the connector and the line circuit of the called station belonging to the satellite office are released as described in the chapter "Calls from Main Extensions to Individual Main Extension Lines" with regard to equivalent switches.



   We will now consider the case where the traffic leaving the central office to the satellite office is sufficiently large to require a considerable number of junction circuits between the two offices if the junction circuits

  <Desc / Clms Page number 96>

 outgoing (fig. 3) are connected directly to the blocks of the second local selector as indicated in the explanation above about a call from a central station to a station in the satellite office.

   In this case the number of junction circuits between the two offices can be appreciably reduced by the use of distributors or distributors of outgoing junction circuits, interposed between the benches of the second local selectors of the main office and the outgoing junction circuits, seen that the use of such distributors makes it possible to reduce the number of outgoing trunk circuits required.

   When using outgoing trunk circuit distributors, conductors 1035, 1036 and 1037 (fig. 10) are connected to a set of tenth level bench pads of the second local selector (fig. 6) in the main office. , and the conductors 1000, 1001 and 1002 (fig. 10) are connected to the conductors 1300, 1301 and 1302 of the outgoing junction circuit (fig. 13), the corresponding conductors of other distributors of outgoing junction circuits being of even connected to other sets of bank studs on the second local selectors (fig. 6) and outgoing junction circuits (fig. 13).

   The other switches of the switching train intended to establish communications from the main stations to the stations in the satellite office are arranged and connected as described in detail in the first paragraph of this chapter.



   The outgoing trunk distributor (fig.



  10), operates: the preselection of a free outgoing junction circuit (fig. 13). If the outgoing junction circuit on which the wipers 1027, 1028 and 1029 are stopped is already seized by another switch also having access to this circuit, the earth potential on the conductors 1002 will be applied by: wiper 1029, armatures 1041, 1071 , disconnecting armature 1031, winding of relay 1050, battery with excitation of the

  <Desc / Clms Page number 97>

 relay 1050. At armature 1051, this relay closes the circuit of electro 1030, so that the latter attracts and places its pawl in a position preparatory to the advancement of rubbers 1027, 1028 and 1029 of a not.

   At the cut-off armature 1031, the electro 1030 cuts the circuit of the relay 1050, and the latter drops out and cuts the circuit of the electro 1030 at the armature 1051. Therefore, this electro releases, by advancing the friction. - teurs 1027, 1028 and 1029 of one step. If the next outgoing junction circuit is busy, the slider 1029 finds a ground potential on the conductor 1002 of the last-mentioned outgoing junction circuit, and this ground connection will cause the 1050 relay to attract again and close a once again the circuit of the electro 1030. The latter attracts again and places its pawl in a position preparatory to the advancement of the wipers 1027, 1028 and 1029 by another step, while cutting the relay circuit 1050.

   Stepping and testing continues until slider 1029 reaches a bench pad of a free outgoing trunk circuit. When the last free outgoing junction circuit has been "preselected", the common "All Junctions Busy" relay 1060 drops out, as the last earth connection to common conductor 1059 is removed at armature 1313 of the last junction circuit. outgoing free and that, at armature 1061, relay 1060 closes the circuit of common relay 1070. Excitation of common relay 1070 cuts off the circuit of relay 1050 at armature 1071, so that the electro 1030 cannot plus produce a step-by-step advancement.



  When an outgoing trunk circuit becomes available again, the "All Trunk Busy" relay 1060 is pulled to release the common relay 1070, thereby preparing the circuit from relay 1050 to armature 1071.



   It will now be assumed that the outgoing trunk circuit distributors are used as indicated in a previous paragraph of this chapter. In this case, an earth potential

  <Desc / Clms Page number 98>

 applied by: armature 613 and its working pin, lower coil of relay 630, wiper 618, conductor 1037 of the distributor (fig. 10), coil of relay 1040, armature 1041, 1071, cut-off armature 1031, coil of relay 1050 and battery, will cause relay 1040 to actuate (relay 1050 does not operate at this time); on the other hand, the earth potential applied by:

   armature 613 and its working pin, lower coil of relay 630, wiper 618, conductor 1037 of the distributor (fig. 10), resistor 1045 in parallel with the coil of relay 1040, wiper 1029, conductor 1002, conductor 1302, upper coil of the relay 1310, lower winding of relay 1330 and battery, causes actuation of relay 1310 (relay 1330 being normally attracted).



   Operation of relay 1040 breaks the circuit of relay 1050 to armature 1041 and connects a ground potential to conductor 1043 of the communications meter (not shown) to armature 1042 * When pulling, relay 1310 grabs the junction circuit outgoing in a manner similar to that described in the third paragraph of the chapter "Calls from the Satellite Office to the Main Office".

   From this moment the description of the establishment of a communication by the third selector on arrival (fig. 14) of the satellite office, the fourth local selector 780 of the satellite office and the connector (fig. 7) of the office satellite is the same as that contained in the first part of this chapter for the case where the conductors 1300, 1301 and 1302 of the outgoing junction circuit are connected directly to a set of bench pads of the tenth level of the second local selector (figo 6).



   Collage of Local Communications for Malicious Call Tracing.



   If the user of a station called in a local call wishes to know the identity of the calling station, in the case where

  <Desc / Clms Page number 99>

 the call can be considered as malicious, the called station does not hang up but keeps the communication after the calling station hangs up. It will now be assumed that the selectors according to figs. 5 and 6 and the connector (fig. 7) were used to connect the calling station to the called station, and that the party at the calling station hung up without revealing his identity. In this case, the called party's caller keeps the call to prevent the switch train from being released and to attract the attention of a supervisor in the originating office to have the call tracked.

   Under these conditions, the relay 750 of the connector remains attracted and the earth is therefore applied to the relay 540 of the first selector by: armatures 711, 755, armature 745 and its working pin, upper coil of relay 700, conductor 725, conductor 641 (fig. 6), bench block "-" connected to the slider 616, slider 616, armature 631, conductor 535, bench block "-" connected to the slider 527, slider 527, armature 552, armatures 511, 522 and their rest pads, thus retaining the relay 540 in the drawn position. So the circuit of the release electro 525 of the first selector is cut to the armature 542, and the earth is connected to the wiper 529 by the armature 543 and its working pad, to keep the second selector actuated.

   Therefore, the switch train is not released at this time.



   The relays 500 and 510 were released as a result of hanging up at the calling station, which had the effect of closing a circuit of the supervisory alarm lamp 533 by: earth, armatures 502,514 and their rest pads, armature 542 and its work pin, lamp 533, battery. The supervisor is therefore informed that the connection via the first local selector (fig. 5) has been maintained and that his attention is required.



  The supervisor then inserts his plug into the test jack (not shown) of the selector (fig. 5), thus breaking the circuit from lamp 533 to armature 502 and converses with the called local station.

  <Desc / Clms Page number 100>

 



  The supervisor then proceeds using one of the following two methods:
First method: The supervisor invites the called station to stay on the call and follows the connection to the track to the calling station. Having determined the identity of the calling station, the supervisor then transmits the information to the station called on hold, invites it to hang up and removes its plug from the selector test jack (fig. 5). As a result of hanging up the called station, relay 750 drops off and removes earth from the "-" side of the connection to armature 755 allowing relay 540 of the first selector to drop after a brief interval.

   At armature 542, relay 540 closes the circuit of the release electro 525 by: earth, armatures 502, 514, 542 and their rest pads, armature 556, armature spring 516, coil of electro 525 , drums ; at reinforcement 543, it eliminates the earth from the wiper 529. From this moment on, the set of switches is released as described in the chapter "Main substations calls to individual main substation lines".



   Second method: The supervisor activates the occupancy key 519 of the selector (fig. 5), invites the called party to hang up and then removes his plug from the selector test jack (fig. 5). The actuation of the occupancy key 519 applies a bonding earth on the conductor 272 to maintain the circuit of the cut-off relay of the calling station, and hanging up at the called station releases the relays 750 and 540. The electro circuit release 525 of the selector (fig. 5) is now closed to the frames 502,514, 542 and their rest pads, and the first selector.

   (fig. 5) and the following switches are released as described in the chapter "Calls from Main Extensions to Individual Main Extension Lines", The supervisor then follows the connection to the track to the calling station and, after determining

  <Desc / Clms Page number 101>

 the identity of the latter, returns the occupancy key 519 to its normal position in order to free the searcher (fig. 2) and the calling station cut-off relay.



   In the event that the local communication has been established with the participation of the discriminator selector according to Figs. 11 and 12, instead of the first local selector according to fig. 5, relay 1240, release electro 1275 and occupancy key 1109 would operate in a manner analogous to that just described with respect to relay 540, release electro 525 and occupancy key 519,
Release by "Foreclosure" of Junctions from the Satellite Office to the Main Office.



   When the user of a calling station from a satellite office equipped with discriminating selectors according to figs, 11 and 12 fails to operate the dial within a predetermined time after initiation of a call, the equipment " foreclosure "will prevent that user from occupying the seized outgoing trunk circuit (Fig. 13) after this time has elapsed. However, in this case the busy discriminator selector is not disconnected from the calling station and the latter can therefore set up a local call to the satellite office after having been the subject of a "foreclosure" with regard to the outgoing trunk circuit. that was entered when the appeal was initiated.

   The purpose of releasing the outgoing trunk circuit entered in the event that the user of the calling station fails to operate the dial within a determined time is to prevent unjustified occupation of the outgoing trunk circuit entered. In certain cases of deferred dialing, the user of the calling station wishes to transmit a local number of the satellite office and it would therefore be unnecessary for him to occupy the outgoing trunk circuit entered; while in cases where this user intends to dial a number from the main office, he is not entitled to defer the numbering beyond a fixed period.

  <Desc / Clms Page number 102>

 



   It will now be assumed that a satellite office set has initiated a call but has not started dialing. In this case, the discriminator selector (figs, 11 and 12) has entered an outgoing trunk circuit (fig. 13) in the manner described in the chapter "Local calls to the Satellite Office". A duration counter (timer) 1175 periodically connects an earth pulse through the duration conductor or periodic pulse generator 1173 to the coil of the relay 1170 of the selector discri. miner by the rest pad of the armature 1171. This earth pulse only causes the operation of the relay 1170 when the two armatures 1136 and 1236 are connected to their respective work pads.

   Relays 1130 and 1230 occupy the attracted position after initiation of the call and before the caller begins dialing, and remain in this position until the end of the first dialing period, after which relay 1230 drops out. . So the closing of the circuit through the coil of the relay 1170 is only possible when the armatures 1136 and 1236 and their respective working pads are closed during the period when an earth pulse is received on the conductor 1173. Therefore, if l The caller omits to number before applying the earth pulse to conductor 1173, this pulse is transmitted by: coil of relay 1170, armature 1136 and its work pad, conductor 1207, armature 1236 and its work pad , electro coil 1270, battery.

   The relay 1170 attracts in the circuit thus established, but the high resistance of its winding prevents the actuation of the electro 1270.



   The operation of relay 1170 closes a blocking circuit for this relay by the earth applied through the armature 1115 and the armature 1171 and its working pin, independently of the earth pulse applied to the conductor 1173. A armature 1172, relay 1170 transfers the blocking circuit of the lower winding of relay 1210 to armature 1115 and

  <Desc / Clms Page number 103>

 rest pad of the reinforcement 1172 to a "timed holding ground" by the conductor 1174; therefore, if the relay 1230 has not been released by sending the first digit by releasing the relay 1170, the expiration of the timed sticking period on the conductor 1174 will have the effect of unblocking the relay 1210 and therefore the release outgoing trunk circuit seized.

   It will now be assumed that the occupation of the outgoing trunk circuit has been "foreclosed", that this circuit has been released as indicated in the previous paragraph, and that the caller begins dialing a local number of the satellite office. . In this case, such a communication is established as described in detail in the chapter "Local calls to the Satellite Office".



   "First Digit Discriminator Selector Intervention".



   In the chapter "Calls from the Satellite Office to the Main Office", the description of the operation of the discriminator selector (figs. 11 and 12) includes the arrangement by which the discrimination, in this selector, between a call intended for a local number of the satellite office and a call to a main office number is made after the second digit. However, the discriminator selector is on the other hand set so that discrimination can take place after the first digit, so that this selector "comes into play" or "comes in" after the first digit instead of it. do after the third number as indicated in the above chapter.



  The "in-game" or "intervention" after the first digit is used to connect trunk groups to exchanges other than the associated central office, for example directing junctions to an adjacent office having a first different from that of the satellite office, or for junctions going to an interurban operator's table, and the like.

  <Desc / Clms Page number 104>

 



   In order to describe a call from a local station of the satellite office with regard to a number with "intervention" after the first digit, it will be assumed that station C (fig.ll) initiates a call for connection to a junction going to a nearby long-distance operator's table, and that the first digit of the code number of this table is nine (9). It will also be assumed that the ninth level of the bench blocks associated with the wipers 1227, 1228 and 1229 of the discriminator selector is connected to the junctions going to the aforementioned table (not shown), and that the wipers 1237, 1238 and 1239 of the seeker of outgoing junction (fig. 12) are stopped on a junction going to a free outgoing junction circuit (fig. 13).

   It will also be assumed that the rubbers 1124, 1125 and 1126 of the searcher 1108 have found the line circuit 1107 of the station C and sty are connected, in a manner analogous to that described in the chapter "Calls from Main Stations to Main Station Lines Individual ". Under these conditions, the line relay 1100 of the discriminator selector is kept activated on the calling loop of station C, and the relay 1330 of the outgoing junction circuit is kept attracted in the manner described in the second paragraph of the chapter "Calls from the Satellite Office to Main Office 'The discriminator selector relays 1230 and 1210 are also drawn as described in the second paragraph above.

   At armature 1216, relay 1210 closes a circuit of relay 1130 by: earth, armature 1113 and its working pin, conductor 1190, armature 1216, conductor 1191, upper coil of relay 1130, battery, so that relay 1130 attracts and is blocked to the earth by armature 1113 and its working stud and armature 1132. At armature 1131, relay 1130 sends an operating signal to the calling station and, when it perceives this signal, the The caller dials the operator's table code number, the first digit of which is 9.

  <Desc / Clms Page number 105>

 



   Following the formation of the first digit (9), the circuit of relay 1100 is cut nine times. Relay 1100 drops momentarily with each pulse and armature 1102 breaks the circuit of relay 1110, but the latter does not drop during the pulse period. At armature 1102 and its rest pad, relay 1100 transmits an impulse to the ascension electro 1260, to relay 1240 and to the upper coil of relay 1230 on each de-energization. Relay 1240 attracts and does not drop during the pulse period. At armature 1244, relay 1240 connects a "multiple earth" to the upper coil of relay 1130. The latter is also delayed release and does not drop out during the pulse period.



  Electro 1260 attracts and falls with each de-energization and re-energization of relay 1100, raising the shaft and the discriminator selector wipers by a corresponding number of vertical steps (in this case the shaft and the wipers are raised at the ninth level).



   Shortly after receiving the last pulse of the first digit, relays 1240 and 1230 drop out. At the rest pad of armature 1232, relay 1230 maintains a "direct earth" on the lower winding of relay 1100. At armature 1234, relay 1230 closes a circuit of relay 1160 by: earth, armature 1234, conductor 1194 going to fig. 15, frame 1162 and its rest stud, wiper 1139 of the vertical bench 1138, stud n 9 of this bench, frame 1143, conductor 1197 going towards FIG. 12, armature 1276, conductor 1202, lower and upper windings of relay 1160 in series, battery, so that relay 1160 attracts and locks to the circuit by: earth, armatures 1115, 1165, lower and upper windings of relay 1160 in series , drums.

   At armature 1231, relay 1230 cuts the circuit of its upper winding as well as of the lift electro 1260. At armature 1166, relay 1160 closes the circuit.

  <Desc / Clms Page number 106>

 of relay 1220 by: earth, armature 1115, conductor 1200, armature 1257 and its resting pin, armature spring 1247 and its working pin, conductor 1201, armature 1166, conductor 1204, rupture armature 1266, winding of the relay 1220, battery, with actuation of relay 1220; and, at armature 1167, relay 1160 cuts off the lower coil blocking circuit of relay 1210.

   Releasing the latter disconnects the transmission circuit from the outgoing junction circuit to armatures 1212 and 1213, and, at armature 1219, removes earth from wiper 1239 to free the rushing circuit. outgoing tion seized. The discriminator selector is now ready to turn its wipers in the ninth level of the bench blocks.



   The operation of relay 1220 closes the circuit of the rotation electro 1265 by: earth, armature 1234, conductor 1194, armature 1162 and its working pin, conductor 1195, armature 1221, winding of electro 1265, battery.



  The electro 1265 attracts and turns the shaft and the discriminator selector wipers one step in the ninth level of the bench blocks. It will now be assumed that the junction connected to the first set of ninth level bench studs is free.



  In this case, the wiper 1229 of the discriminator selector encounters a battery potential supplied by means of the junction to the pin C of the first set of bench pads, and a circuit of the relay 1250 is closed by: earth, armature 1115, conductor 1200, armature 1277 and its rest pad, upper coil of relay 1250, wiper 1229, to the battery connected to bench pad C connected to wiper 1229, so that relay 1250 attracts and prevents subsequent rotation pulses - inputs from the disoriminator selector by cutting the circuit of relay 1220 to armature 1257.

   At armature 1257, relay 1250 also closes a blocking circuit for its lower winding; to the frame 1258 and its working stud it short-circuits

  <Desc / Clms Page number 107>

 its upper winding, thus connecting a direct earth through the armature 1277 and its rest pad to the wiper 1229 as an occupying guard, as well as to occupy the chosen junction; to reinforcement 1254 it connects a multiple earth to conductor 1129 of line finder 1108; and, to the frames 1252 and 1253 extends the transmission circuit from station C to the chosen junction. From this point, reestablishment of communication to the trunk attendant table is carried out in the conventional manner and, as this does not relate to the present invention, it is unnecessary to explain it further.



     Fourth Digit Discriminator Selector "Intervention".



   In the chapter "Calls from the Satellite Office to the Main Office", the description of the operation of the discriminator selector (figs. 11 and 12) includes the arrangement by which the discrimination, in this selector, between a call intended for a local number of the satellite office and a call to a main office number is made after the second digit. However, the discriminator selector can be set so that discrimination can take place after the third digit.



  In order to describe a local call to the satellite office in the case where the discriminator selector is set so that the discrimination between a local call and a call to the main office is after the third digit, it will be assumed that the station C ( fig. 11) initiate a call to establish communication with another local extension in the satellite office, and all local extension numbers begin with the code 506 followed by three additional digits. It will also be assumed that the connections to the vertical bench 1138 and to the vertical wiper 1139 are established according to FIG. 15 instead of being according to FIG. 11, the wiring, not shown in fig, 15, being identical to that of fig. 11.

   It will also be assumed that the rubbers 1124, 1125 and 1126 of the searcher 1108 have found the

  <Desc / Clms Page number 108>

 line 1107 of station C and stopped there in a manner analogous to that described in the chapter "Calls from Main Substations to Individual Main Substation Lines", and that the wipers 1237, 1238 and 1239 of the circuit finder outgoing junction (fig. 12) are stopped on a junction going to a free outgoing junction circuit according to fig. 13.



  Under these conditions, the line relay 1100 of the selector discri. caller is kept attracted to the calling loop of station C, and the relay 1330 of the outgoing trunk circuit is kept attracted as described in the second paragraph of the chapter "Calls from the Satellite Office to the Main Office". The discriminator selector relays 1230 and 1210 are also drawn in the manner described in the second paragraph above. At armature 1216, relay 1210 closes a circuit of relay 1130 by: earth, armature 1113 and its resting pad, conductor 1190, armature 1216, conductor 1191, upper coil of relay 1130, battery, and relay 1130 attracts and is blocked to the ground by the frame 1113 and its working stud and the frame 1132.

   At armature 1131, relay 1130 sends an operation signal to the calling station and, when it perceives this, the calling party dials the number of the local station requested (for example 506399). It should be remembered that the right rest shaft contact 1147 of the discriminator selector is set to make contact when the shaft of this switch reaches the fifth level (the first digit of the local number being 5), and that the contact Idle Shaft Left 1148 is set to make contact when the switch shaft reaches the tenth level (the second digit of the local number being 0).



   The operation of the discriminator selector following the formation of the first digit (5) and the second digit (0) of the desired local number is the same as that described in the chapter "Local calls to the Satellite Office" regarding the first digit (5 ) and the second digit (0); it is therefore unnecessary to repeat here

  <Desc / Clms Page number 109>

 these operations. Shortly after receiving the last pulse of the fourth digit, relays 1230 and 1240 drop out.

   At the rest pad of the armature 1232, the relay 1230 maintains a direct earth on the lower winding of the relay 1100; and, at armature 1234, it closes a circuit of the release electro 1275 by: earth, armature 1234, conductor 1194, armature 1142 and its working pin, left rest shaft contact 1148, armature 1151 and its rest pad, armature 1133, conductor 1196, electro coil 1275, battery, Operation of electro 1275 causes the shaft of the discrimination selector to drop by gravity to the normal position, and the This electro circuit is cut at the left rest shaft contact 1148. The ascension shaft contact 1245 returns to the normal position when the switch shaft reaches its normal position.

   On the other hand, the excitation of the electro 1275 closes a circuit of the relay 1150 by: earth, armature 1115, conductor 1200, armature 1277 and its rest pad, conductor 1198, armature 1144 and its work pad, armature 1153 and its rest pad, upper winding of relay 1150, battery, and, a second circuit of relay 1150 by: earth, armature 1115, conductor 1200, armature 1277 and its working terminal, conductor 1198, armature 1144 and its work post, armature 1153 and its rest post, lower coil of relay 1150, armature 1145 and its work post, armature 1154 and its rest post, armature 1164, resistor 1168, battery. However, relay 1150 does not attract because its two windings are energized in opposite directions.

   The cutting of the two circuits of relay 1150 at armature 1277 by releasing electro 1275 causes a momentary magnetic imbalance between the two windings of relay 1150 and, consequently, relay 1150 attracts and blocks by: earth, armatures 1115 , 1155, lower and upper windings of relay 1150 in series, battery. The works'-. ment of relay 1150 cuts the rest contact of armature 1156

  <Desc / Clms Page number 110>

 with this armature, but the wire 1157 shunting the armature 1156 and its resting pin (figo 15) prevents the cutting of the blocking circuit of the lower coil of the relay 1210, and the latter therefore does not drop out at this time.

   Releasing the ascension shaft contact 1248 closes a circuit of relay 1230 so that the latter again draws and maintains a direct earth on the lower coil of relay 1100 through armature 1141 and its stud of the conductor 1185, of the frame 1232 and its work block and of the conductor 1184.



   Following the sending of the third digit (6) the circuit of relay 1100 is interrupted six times, and impulses are consequently transmitted to the ascension electro 1260, to relay 1240 and to the upper coil of relay 1230 by the earth and the rest contact of the armature 1102. The relays 1240 and 1230 do not drop during the impulses o The electro 1260 attracts and releases with each impulse, raising the shaft and the rubbers of the discriminator selector to the sixth level of the blocks from the bench.



   Shortly after receiving the last pulse of the third digit, relays 1230 and 1240 drop out. At the rest pad of the armature 1232, the relay 1230 maintains a direct earth on the lower winding of the relay 1100; and, at armature 1234, closes a circuit of the release electro 1275 by: earth, armature 1234, conductor 1194 going towards FIG. 15, frame 1162 and its rest stud, vertical wiper 1139, stud n 6 of the vertical bench 1138, frame 1151 and its working stud, frame 1133, conductor 1196 going towards FIG. 12, coil of electro 1275, battery, Energizing electro 1275 causes the shaft of the discriminator selector to drop back to the normal position, and the circuit of electro 1275 is cut when the vertical rub is released.

   The lift shaft contact 1245 returns to the normal position when the switch shaft reaches its home position. On the other hand, the exci-

  <Desc / Clms Page number 111>

 operation of the electro 1275 closes a circuit of the relay 1160 by: earth, armature 1115, conductor 1200, armature 1275 and its work pin, conductor 1198, armature 1144 and its work pin, armature 1153 and its work pin, armature 1163 and its rest pad, upper coil of relay 1160, battery; and, a second circuit of relay 1160 by:

   earth, armature 1115, conductor 1200, armature 1277 and its work stud, conductor 1198, armatures 1144, 1153 and their work pads, armature 1163, lower coil of relay 1160, armature 1154 and its work pin, armature 1164 , resistor 1168, battery.



  However, relay 1160 does not attract, because its two coils are energized in opposite directions. The cutting of the two circuits of the relay 1160 to the armature 1277 by releasing the electro 1275 causes a momentary magnetic imbalance between the two windings and, consequently, the relay 1160 attracts and locks in the circuit: earth, armature 1115 , armature 1165, upper and lower windings of relay 1160, battery.



  At armature 1167, relay 1160 cuts the blocking circuit of the lower winding of relay 1210, where the latter is released. This release has the effect of disconnecting the transmission circuit from aveo the outgoing junction circuit to the armatures 1212 and 1213; and, at armature 1219, removes earth from wiper 1239 to free the seized outgoing junction circuit. Releasing the ascension shaft contact 1245 closes a circuit of relay 1230 so that the latter again attracts and maintains a direct earth on the lower winding of relay 1100 by: armature 1141 and its working pin, conductor 1185, armature 1232 and its work block, conductor 1184.



   Following the sending of the fourth digit (3), the circuit of relay 1100 is cut three times, and pulses are transmitted accordingly to the electro-ascension 1260, to the relay 1240 and to the upper coil of the relay 1230 by the

  <Desc / Clms Page number 112>

 earth and the rest contact of the armature 1102. The relays 1240 and 1230 do not drop during the pulses. The electro 1260 attracts and releases with each impulse by raising the shaft and the rubbers of the disoriminator selector to the third level of the bench blocks.

   The ascension shaft contact 1245 is actuated with the first vertical pitch of the shaft, closing the circuit of relay 1220 by: earth, armature 1115, conductor 1200, armature 1257 and its resting pin, spring of armature 1247 and its working pin, conductor 1201, armature 1166, conductor 1204, cut-off spring 1266, coil of relay 1220, battery, with energization of relay 1220. Shortly after receiving the last pulse of the fourth digit, relays 1240 and 1230 fall. At the rest pad of the armature 1232, the relay 1230 maintains a direct earth on the lower winding of the relay 1100; and, at armature 1231, cuts the circuit of its upper winding and that of the electro-ascension 1260.

   The operation of relay 1220 closes the circuit of the rotation electro 1265 by: earth, armature 1234, conductor 1194, armature 1162 and its working pin, conductor 1195, armature 1221, coil of electro 1265, battery.



   The electro 1265 attracts and turns the shaft and the rubbers of the discriminator selector by one step in the third level (level n 3 selected by the pulses of the fourth digit). On the other hand, the actuation of the electro 1265 cuts the circuit of the relay 1220 to the cut-off armature 1266, so that this relay drops out and cuts the circuit of the electro 1265 to the armature 1221. This electro drops in turn and closes the circuit of relay 1220. This reciprocal action between electro 1265 and relay 1220 continues until wiper 1229 encounters a battery potential on pin C of a set of bench pads. connected to a free next switch.

   It will now be assumed that this switch is the connector according to fig. 7, In this case, establishing communication to

  <Desc / Clms Page number 113>

 the called set (506399) and the final interruption of this communication are analogous to what has been described in the chapter "Local calls to the Satellite Office" concerning equivalent operations, and it is therefore unnecessary to explain these operations in detail in this chapter.



   It is therefore understood that the discriminator selector can be set so that it can not only "intervene" at the fourth digit, as described in this chapter, but also "intervene" at the first digit on at least one level. Therefore, fig. 15 was set to show that pad # 6 of vertical bank 1138 is connected to provide "fourth digit intervention", and pad # 9, to provide "first digit intervention". Operation by "first digit intervention" is explained in detail in the chapter "Intervention" of the First Digit Discriminator Selector ", and there is therefore no need to repeat these details in this chapter.



   "Intervention" and Cut-off by the Interurban Operator.



   According to the present invention, calls can be made from the long distance operator table to automatic local stations and, in addition, the long distance operator can "step in" in an ongoing call and offer a long distance call to the local station. request. The interurban operator can also, if conditions allow it, decon. connect the local extension requested with the call in progress and make the long distance call to the disconnected local extension, without having to dial the local number again.



   Fig. 9 shows the elements and circuit details of the equipment of a long distance operator, which relate directly to the present invention. All other circuit elements and details have been omitted in the drawing as not being essential and in order to simplify the explanation. It should be noted, however, that

  <Desc / Clms Page number 114>

 the trunk attendant equipment may include all of the conventional and well-known accessories and elements for maintaining long distance service, to and from stations in the local central office network.



     The interurban operator equipment according to fig. 9 comprises the wipers 927, 928 and 929 of the first interurban selector, the banks of which are connected to junctions going to the first selectors as shown in fig. 6.



   In addition, the long-distance operator has facilities indicated by contacts 970 and 971 respectively, for connecting a battery potential to the "+" conductor of the transmission circuit in order to "intervene" in a communication in progress. current, and to connect an earth potential to the "-" conductor in order to interrupt a communication previously established to or from the requested local station.



   In order to describe the method by which the long distance operator "intervenes" in a communication in progress, "cuts" this communication to free the local extension requested, and places the long distance call to this extension thus released, it will be assumed that a communication was established between two automatic local stations, as shown in the simple summary diagram in fig. 16, and that the long distance operator wishes to establish a long distance call to the requested local extension participating in the local call in progress.

   In fig. 16, the calling station cut-off relay is shown to be kept attracted by the earth applied to the upper coil of the call finder relay 220, armature 223 and its work pin, and armature 513 and its work pin. the first selector; on the other hand, the cut-off relay of the called station is shown as attracted by the earth applied to the lower winding of the connector relay 730, the armatures 736, 737, 757 and their working pads. The conversation circuit between the calling and called stations is closed by the

  <Desc / Clms Page number 115>

 reinforcements 221, 222, 733, 734 and their working blocks. A detailed description of the communication between these sets can be found in the chapter "Calls from Main Extensions to Individual Main Extension Lines".



   It will now be assumed that the long distance operator has activated the first selector by forming the first digit of the number of the desired local extension, so that the wipers 927,928 and 929 are connected to the conductors 935,936 and 937 going to the second selector (fig. 6). ; that it has formed the second digit to cause the second selected selector to enter a free connector, for example that of FIG, 7; and that it has formed the last two digits of the requested number, to cause the wipers 786, 787 and 788 to be placed on the multiplied bench pads of a connector corresponding to the requested local station. In this case, the long distance operator receives a busy signal indicating that the requested local extension is busy with another call.

   The busy signal circuit can be established as follows: armature spring 774 and its working pin, armatures 761, 731, 751, capacitor 708 and armature 721 at the "-" side of the transmission circuit returning to the equipment from the long distance operator.



  By perceiving the busy signal, this operator decides to “intervene” in the local communication, and, consequently, connects a battery potential to the “+” conductor of the transmission circuit by actuating the contact 970.



   The actuation of the contact 970 closes the circuit of the lower and middle windings of the relay 750 of the connector by: trotter 928, conductor 936 going towards fig. 6, conductor 536, frame 632, wiper 617, conductor 642 going towards FIG. 7, conductor 726, armature 743, lower and middle windings of relay 750, earth, with attraction of relay 750.



  At armature 751, relay 750 cuts off the busy signal circuit; and, to reinforcements 751 and 753 extends the circuit of

  <Desc / Clms Page number 116>

 transmission from the interurban attendant's table through the wipers 786 and 787 to the bench multiplication of the connector which controls the requested local set, so that this attendant can converse with the two local sets using the local connection. The operator then offers long distance communication to the local extension requested.



   We will now assume that the long distance operator will "cut" the local call and place the long distance call to the called local extension. In this case, the attendant connects an earth potential to the "-" conductor of the transmission circuit by actuating contact 971. Actuation of this contact closes a circuit of the upper winding of the connector relay 700 by means of: wiper 927 , conductor 935 going towards FIG. 6, conductor 535, armature 631, wiper 616, conductor 641 going towards FIG. 7, conductor 725, upper coil of relay 700, armature 745 and its rest pad, resistor 717, battery, hence the attraction of relay 700.

   At armature 702, this relay closes a circuit of relay 760 by: earth, armature 757, armature 737 and its rest pad, armature 702, lower coil of relay 760, battery, so that relay 760 attracts; and, to the armature 701, the relay 700 connects a direct earth to the wiper 788 through the armature 747 and its rest pad and the armature 756.



   The direct earth on the slider 788 of the connector used by the long-distance operator is extended through the bank multiplication of the connector to the winding of the cutoff relay of the local station called, thus closing a sticking circuit for the cutoff relay independently connector (fig. 16) used for local communication. On the other hand, this direct earth shunts the lower winding of relay 730 of the connector (fig. 16), hence the triggering of relay 730. At armatures 733 and 734, relay 730 disconnects the transmission circuit of the local station called, by releasing relay 750.

  <Desc / Clms Page number 117>

 



  The called local set is now released from the connector (fig. 16), and its cutout relay is kept stuck by the direct earth coming from the connector of the long distance operator. Triggering relay 750 (fig. 16) connects a busy signal to the transmission circuit of the calling local station to armature 751 and, when this last station hangs up, the set of switches used for local communication. is released in the manner explained in the chapter "Calls from Main Extensions to Individual Main Extension Lines".



   After the trunk attendant has actuated contact 971, thus cutting off local communication, she releases contacts 970 and 971, so that relays 750 and 700 of the intercity train connector drop out. At armature 757, relay 750 eliminates the earth of the lower winding of relay 760, but the latter, being with delayed release, remains attracted for a brief interval after its circuit has been cut.



  To promote the delay in tripping relay 760 after cutting the circuit of its lower winding than armature 757, a circuit of the upper coil of relay 760 is closed by: earth, armatures 713, 764, resistance 718, upper coil of relay 760, battery, when the circuit of the lower coil of relay 760 is closed. Resistor 718 has a sufficient value to prevent relay 760 from sticking indefinitely in the circuit comprising its upper coil and resistance 718.

   At armature 756, relay 750 eliminates the direct earth of the wiper 788, so that the relay 730 attracts by: earth, armatures 713, 764, 723, upper coil of relay 730, armature 748 and its rest pad, winding lower relay 730, wiper 788, bank pad C connected to this wiper, connector bank multiplication, winding of the cut-off relay of the local station called, battery. Relay 730 is blocked in the circuit: earth, armatures 713, 736, lower winding of relay 730, wiper

  <Desc / Clms Page number 118>

 788, bench pad C connected to this wiper, connector bank multiplication, winding of the cutoff relay of the local station called, battery.

   At armatures 733 and 734, relay 730 closes the direct current loop of the local substation called, by the upper coil of relay 740, so that the latter attracts and blocks by: earth, armatures 713, 749, lower coil of the relay 740, battery,
At armatures 741 and 742, relay 740 cuts the circuit comprising its upper winding; armatures 741,742 and their work pads, it closes the direct current loop of the local station called, passing through the upper and middle windings of relay 750, hence the attraction of relay 750, and, to armatures 741,742 and their work pads, extends the transmission circuit from the long distance operator's equipment to the called local station, At armature 757, relay 750 connects a multiple earth to wiper 788 by:

   armature 737 and its working block, armature 736 and the lower winding of relay 730, and on the other hand connects a multiple earth to the lower winding of relay 740 by armature 737 and its working block and armature 749 If the user of the local station called hung up before Empress interurban has finished cutting off the local communication, this station will automatically receive a signal through the upper coil of relay 740 and the rest pads of reinforcements 741 and 742. following the closing of armatures 733 and 734 by the operation of relay 730.



   It will now be assumed that the local set whose number was dialed by the long distance operator is the calling set of the local communication according to fig. 16. In this case, the actuation of contact 971 by the long-distance operator has the effect of applying a direct earth through the wiper 788 of the connector used by this operator, and through the bench multiplication of the connector, to the winding. relay of

  <Desc / Clms Page number 119>

 disconnection of the calling station (fig. 16), thus closing a sticking circuit for the cutting relay independently of the line finder used in the lccal communication. This same earth on the other hand shunts the upper winding of relay 220 of the line finder, so that this relay drops out.

   At armatures 221 and 222, relay 220 disconnects the transmission circuit of the calling local station, so that relay 500 of the first selector drops out and the train of switches used for local communication is released as described in the chapter "Calls from Main Stations to Individual Main Post Lines ". The local calling station is now clear of the line finder (fig. 16), and its breaking relay is kept attracted by the direct earth coming from the connector of the long distance operator. From this moment on, the operation of the connector used by the long distance operator is the same as that described when the set with which the long distance operator wishes to communicate is the called set participating in the local call.



   In the previous paragraph it was assumed that the multiplication of the calling station was housed in the lower banks of the line finder and that, consequently, the finder relay 220 was the blocked relay of the finder which was shunted by the direct earth. coming from the connector used by the trunk attendant. It should be noted however that this opera. It might just as well be the intention to connect to a calling station controlled by the top benches of the line (or call) finder. In the latter case, the relay 230 of the call finder would be the blocked relay which is shunted by the direct earth coming from the connector used by the long distance operator.


    

Claims (1)

CLAIMS. ------------------------------ 1 - Telephony system in which a calling line can be connected to a switch comprising a slider, and in which the switch is moved following a digit sent on this line, and returns to the normal position (is released) after have been moved, this system comprising means for advancing the released switch, following another digit sent on this line, by actuating the slider of this switch, and means influenced by the operation of the slider, for moving the switch in another way, so that this switch grasps the control circuit. 2 - A telephone system according to claim 1, with main office, satellite office (branch office), an outgoing trunk line from the satellite office to the main office, and a local trunk line to the satellite office, this system comprising a connection established by the outgoing trunk line from the satellite office to the main office following the occupation of a selector by the calling line, this selector being first moved following a series of im - pulses sent by the calling line, and being released after its primary movement, lice be subjected to a second primary movement as a result of another series of pulses sent by the calling line, and then being released, this system further comprising means influenced by the release of the selector after the second primary movement, to put out of effect the connection established to the main office. 3 - Telephone system according to claims 1 and 2, wherein the selector performs a third primary movement following another series of pulses on the calling line, this system comprising a friction in the selector moved by the third primary movement, and means controlled by the movement of the slider so that secondary movement of the <Desc / Clms Page number 121> selector connects the latter to the local trunk line. 4 - The telephony system according to claims 2 and 3, wherein the selector comprises ascent and rotation electros for the step-by-step movement and a release electro, this system comprising means controlled by the electro of ascent in order to move the selector, a contact provided for the selector and controlled by the movement of the latter to cause the operation of the release electro, so as to release the selector, as well as other influenced means by a number sent on the calling line, to cause a second and a third movement of the selector and an operation of the release eleotro to release the selector after each of these movements, the selector rotation electro producing, following the movement of the selector slider, another movement of the selector, with a view to connecting it to the local trunk line, the release of the selector being caused by a third actuation of the release relay. 5 - Telephone system according to claims 2 to 4 comprising a connector selected by the movement of the selector produced by sending digits on the calling line, and means controlled by the calling line to cause the connector to send a signal to the called line, this line controlling means influenced by the response on this same called line, to complete a conversation connection between the two lines, and means controlled by the called line through the connection of conversation, to deactivate the means which are normally controlled by the calling line, in order to release the selector and the calling line, 6 - A telephone system according to claim 5, comprising: a supervision signal, a potential, means controlled by the called line to superimpose the potential on the two con- <Desc / Clms Page number 122> conductors of the conversation circuit between the lines, the superposition of this potential putting out of effect the means for releasing the connector and the selector actuated by the calling line, to prevent the release, by the calling line, of the selector and of the connector, the supervision signal being applied when the calling station tries to cause the release of the selector and the connector to become effective after the superposition of the potential. 7 - The telephone system according to claim 1, in which a switch controlled by a calling line comprises two appliances for step-by-step movements, one of which is actuated by the first, the second and the third digits, this system comprising means for activating said electro after the fourth digit of a number dialed, this only when the third digit of the number dialed has identified the call as being a local call, and further comprising means for activating the second electro only after a fourth digit has caused the operation of said first electro. 8 - Telephone system according to claims 1, 3 and 4, comprising in a selector a set of springs (contact) controlled by a movement of the selector to actuate the release means for the selector, while the selector friction is controlled by a another operation of the selector to actuate the means for releasing it. this. 9 - A telephone system according to claim 8 comprising, in the set of springs, a contact controlled by a movement of the selector to actuate the release means, and a second contact controlled by a second movement of the selector to actuate the release means, the selector slider being actuated by a third movement of the selector to actuate the means for releasing the latter. 10 - A telephone system according to claims 1, 8 and 9, <Desc / Clms Page number 123> with an auxiliary wiper forming part of the selector, and means controlled by the auxiliary wiper for releasing the selector line wipers whenever the operation of the selector has caused displacement of the line wipers and said auxiliary wiper. from one level to another, of the selector. 11 - A telephone system according to claim 1, with a trunk line terminating on an automatic switch to which the calling line is extended by pulses generated by the dial of the calling station, this system comprising: a relay, means time-based to actuate the relay in the event that the user of the calling station fails to operate the dial after a determined time, a time-based control circuit and the means influenced by the actuation the relay to connect the means which maintain the established communication to the time-based control circuit, combined with means influenced by an intervention of the time-based control circuit to cause the holding means to go out of effect when the user of the calling station fails to operate the dial before the time-based circuit ends 'intervenes. 12 - A telephone system according to claim 11, comprising means for putting the time-based control circuit out of effect when the dial is operated by the caller before an intervention of the time-based control circuit. . 13 - Telephone system according to claims 11 and 12 comprising means for causing the operation of the selector following the pulses generated by the dial when the holding means for the communication established EMI123.1 are ineffective, with release of established communication. 14 - Telephone system according to claims 1, and 11 to 13, wherein the time-based circuit occurs after <Desc / Clms Page number 124> the expiration of a second period to put out of effect the means for maintaining an established communication, while the relay is actuated after the expiration of a first time delay period, and the means controlled by the calling station to activate the switch before the second period has expired to cause another intervention of the time relay. 15 - Telephone system according to claim 1, with junction wipers can be brought on outgoing junction lines, and line wipers to which local lines are accessible, this system comprising means for causing a relay to send pulses to ' one of the selector electros to produce the rotation of the junction wipers to select a free outgoing junction, and means to cause this same relay to send pulses to the other electro of the selector to rotate the line wipers to select a line local free. 16 - Telephone system according to claims 1 and 15, wherein the junction rubbers are normally connected to one of the outgoing junction circuits, while the line rubbers have access to the local junction circuits, and wherein the selector has three electros for step-by-step movement comprising means influenced by the occupation of the selector by the calling station to cause a relay to advance one of these step-by-step electros in order to cause the junction wipers to seek an outgoing junction circuit free and to be connected to it when the junction wipers are connected to a busy outgoing junction circuit, and means for causing the selector to enter the free outgoing junction circuit to which the junction rubbers are connected, and countermeans. extended by the calling station following the connection of the junction rubbers to the free outgoing junction circuit to ensure the release of the seized junction circuit, the station <Desc / Clms Page number 125> calling also controlling means for energizing another electro of the selector following the step-by-step movement to cause the actuation of the line wipers for the purpose of moving these wipers, while the relay energizes the third electro of the selector following the step-by-step movement to cause the displaced line rubbers to seek out and connect to a free local junction circuit. 17 - Telephony system comprising: connectors, a line, a group comprising a first line and a second line, each comprising multiplication positions accessible to the connectors, a conductor connecting the first line to a first test pad in each of the first line multiply positions ... range, a second conductor separately connecting the first line to another test pad of the first line multiplication positions, this system comprising a third conductor connecting the second line to the first line. 'one of the test pads of each of the multiplication positions of said second line, the other of said test pads in each of said multiplication positions of said second line having no electrical connection with this second line, a potential, relay pads in said second row to connect this potential to said first conductor when said first row is occupied, so as to pass this potential to said first test pad in each of said first row multi-range positions , means influenced by the fact that a calling connector tests said first test pad in one of said first line multiplication positions and encounters said potential there on that pad to prevent the calling connector from connecting. on said first line, other relay pads in said first line to connect said potential to said second conductor when said first line is occupied, so as to pass said potential to said other test pad in each of said positions of <Desc / Clms Page number 126> first line multiplication, means influenced by the. causes said calling connector to test said other test pad in said first line multiplication position and meets said potential therein to cause said calling connector to select a multiplication position of said second line, relay contacts in said second line for connecting this potential to said third conductor when said second line is occupied by the latter to extend this potential to said first test pad of each of said second line multiplication positions, means influenced by the fact that a calling connector tests the test pad in one of said second line multiplication positions and encounters said potential therein to prevent this last calling connector from connecting to this second line, and means for returning a busy signal when a calling connector attempts to connect to said second line when the latter is busy. 18 - The telephone system according to claim 1, wherein the calling line and the called line are connected by a train of switches comprising a finder provided with a relay normally controlled by the calling line to keep this line connected to the train of switches. , this system comprising a switching table controlled by an operator, means influenced by the fact that the calling line is called from the operator table by the second train of switches so that the latter connects to the first train and means influenced by the fact that the second train connects to the first to send a busy signal to the operator's table. 19 - The telephony system according to claim 18 comprising, in the switching table, means controlled by the operator to cause the second train to intervene despite the occupation of the first train to establish a connection. <Desc / Clms Page number 127> conversation between the operator or switching table and the first train without entering the latter, and means, in the switching table, controlled by the operator to cause the second train to enter the calling line to establish a connection conversation from the switching table to this line and to disable control of the relay by the calling line, so that the calling line is disconnected from the first set of switches. 20 - Telephone system according to claim 1, with main office and satellite office (branch office), in which are housed respectively a calling line and a called line, comprising means reacting to the fact that the two lines disconnect from their conversa link. - tion to cause the switch train of the satellite office to release and thus free the calling line and the outgoing junction circuit of the satellite office, means in the outgoing junction circuit released to generate a high voltage potential and for momentarily connect this potential to the arrival selector at the main office, and means, in the arrival selector of the main office, influenced by the momentary application of the high potential to release the arrival selector, so that the remainder of the main office switch train is released, 21 - The telephony system according to claim 20, comprising means, in the scrtante junction circuit of the satellite office, for momentarily applying said potential a second time to produce the release of the arrival selector if the first momentary application of this potential did not cause the release of this arrival selector. 22 - Telephone system according to claim 1, with supervision lamp which illuminates at full voltage, following the occupation of a second switching member by a first switching member, this system comprising means <Desc / Clms Page number 128> to cause the second switching member seized to enter a third switching member to connect the first switching member to this third member, which can then be actuated by the first switching member, the supervision lamp remaining illuminated at full voltage at following the occupation and the actuation of the third organ, the second organ being released following the release of the first organ, and the third organ being released after the release of the second organ, the supervision lamp illuminating at reduced voltage following the release of the second organ and extinguishing following the release of the third organ to indicate that all the organs are out of their normal state. 23 - A telephone system according to claim 22, comprising means for causing the supervision lamp to remain in the reduced lighting state when the third member does not release, which indicates incomplete release. 24 - Telephone system in substance as described and shown, and for the stated purpose.