BE411648A - - Google Patents

Description

       

    <Desc / Clms Page number 1>
 



  Improvements to telephone systems.

  <Desc / Clms Page number 2>

 



   The invention relates to telephony systems in general and relates more particularly to semi-automatic telephony systems in which the connections between the lines leading to a central office can be established by means of automatic switches controlled by an operator. serving a table in a remote office.



     The main object of the invention is to provide new and improved circuits to simplify and improve the operation of semi-automatic telephone systems. Local battery circuits in which connections are made between local battery lines by automatic switching devices controlled through a control junction that connects the local battery office and a remote control center. This system has been designed to improve service in rural communities by making it possible to control the connection by a remote operator instead of having a local operator.



  This device is intended to replace manual tables with local battery in offices which cannot support the load of a local operator. Offices of this type, controlled remotely, are generally called RCX. In a system of this type when the local subscriber makes a call by activating his magneto it causes the activation of a searcher who searched for his line and alerts the user. remote operator via a control junction leading to the remote center or main office. The remote operator answers the call, transmits by means of the disk on the same control junction and thereby establishes the desired connection to the called local line, she then rings.

   The remote operator then withdraws from the connection and the calling party

  <Desc / Clms Page number 3>

 can release at the end of the communication by activating its generator.



   According to one of the characteristics of the invention, by making a call in an unserved office, the operator is alerted and a free automatic switch is selected, the operation of the selected switch being controlled by the operator via two wires connected in serial and connecting the operator's table to the unserved office while the sending of the inrush current to the called subscriber is controlled by the operator through the same wires connected in parallel.



   According to another characteristic of the invention the connections to the unserved office are established under the control of the operator by means of a two-wire junction, at the local office organs common to all the switches are provided to establish a conversation circuit between the operator and the caller or called through this junction, these devices operate automatically during certain periods of re-establishment of the connection or are controlled directly by the operator.



   According to another characteristic of the invention, a signal is transmitted automatically to the operator when all the switches are engaged, thereby the operator supervises the switches and releases those which are not used, this signal being retransmitted if the The operator answers and operates the disconnection without releasing the devices seized when the call is sent.



   According to another characteristic of the invention, individual members of the subscriber lines are provided to supply them during the conversation and the operation of these units when the subscriber

  <Desc / Clms Page number 4>

 Hanging up the receiver at the end of the call causes a short pulse to be sent which automatically releases the connection.



   The invention will be better understood from the following description of one of its applications for which reference will be made to the appended drawings comprising FIGS. 1 to 6 inclusive giving detailed circuits.



   Referring to fig. 1 it can be seen that the circle in the upper left corner represents a number of local battery subscriber circuits whose rings can be connected either between wire and earth or between the two line wires. The left circle in the lower corner / schematically represents a number of central battery subscriber circuits whose rings are connected either between wire and earth, or between the two line wires. LC represents the line circuit of one of the local battery subscribers, LC - 1 represents the line circuit of one of the central battery subscribers. The relays 51 and 52 constitute a set called a line adapter allowing central battery lines to be connected to such a desk.

   Finder F is a rotary switch
 EMI4.1
 Lypo bion oonnu including Lori bnlaln nvunoonL pan it ln: j each time his electro control is released and remain in the position to which they were last brought.



   Fig. 2 represents the local connector permanently associated with the researcher F. The local connector is of the well-known type with two movements: vertically and in rotation. Toll-PS-1 shaft springs operate when the connector is brought to the level at which the trunk junctions terminate.



   Fig. 3 shows the distributor preselecting the local feeders such as the one shown in fig. 1 and 2.

  <Desc / Clms Page number 5>

 



  The distributor comprises a rotary step-by-step switch mechanically identical to the researcher F and a group of associated relays.



   Fig. 4 represents the common equipment comprising a group of relays common to all the local feeders and controlling them.



   Fig. 4a shows a group of relays which modify the operating conditions of the circuits of fig.



  4 to give the split call. When the organs of fig. 4 and 4a must be interconnected, it is necessary to disregard the dotted lines of fig. 4 and connect the relays of fig. 4a to the general circuit by connecting the corresponding terminals marked by circles.



   Fig. 5 shows a supervision switch allowing the operator of the remote office to supervise the devices of the R.C.X .. This switch is also a rotary step-by-step switch of the well known type. Local emergency equipment represented by a square in the center of the drawing is substantially identical to the remote control center equipment shown in the dotted rectangle in the lower left corner.



  The equipment installed at the remote office includes the usual operator's station, CD call devices, RC2 translating coil, an answer key, a two-position call and control key and signaling devices.



   Fig. 6 shows a trunk trunk terminating at a jack at the remote control center or other remote office. The equipment includes the usual jack and flap annunciator, the RC4 translator coil and the call key. The interurban junctions are accessible from the interurban levels in the benches of the con-

  <Desc / Clms Page number 6>

 local nectors. The trunk junction also terminates at the trunk line circuit shown to the right of FIG. 6.



   A general description of the system and plans having been given, we will now move on to the detailed explanation of the circuits.



   For this purpose it will be assumed that one of the local battery subscribers, namely M, wishes to be connected to another local station. The caller operates the magneto at his station in the usual way and sends an inrush current through his line and through the top winding of line relay 11. The inrush current through the top winding of the line relay. line 11 causes the attraction of this relay which to the armature 13 connects the negative through the winding of the cut-off relay 12 to the third contact of the bank accessible to the researcher brush 61. To the armature 14 the relay 11 closes the circuit passing through the lower winding of the line relay 11, the armature 18, the starting wire of the finder 30, the winding of the starting relay 201 ot ending in positive. Line relay 11 blocks along this circuit and starter relay 201 pulls.

   At armature 15, line relay 11 opens its original circuit of attraction. The start relay 201 by attracting the armature 212 closes the attraction circuit of the slow relay at the attraction 202 and the armature 213 closes the attraction circuit of the relay 203 after the distributor has selected a free junction .



  The relay 202 attracts after a while and the armature 215 closes the short circuit of its winding to delay its release. Relay 202 thereby intermittently pulls and releases and armature 214 connects and disconnects the positive of wire 270 to output

  <Desc / Clms Page number 7>

 a tone on the control trunk, if it is in service for another call the operator will be informed that a subsequent call has been made by another subscriber. The attraction circuit of relay 203 is as follows: wire 262, armature 232 and contact at rest, wire 273, armature 330, wire 281, armature 237 and contact on, armature 245, armature 213, winding of relay 203, springs control solenoid 253 switches 245, control solenoid winding 253, negative.

   In the case where the distributor brushes have remained engaged on an occupied feeder, the positive on the guard wire 65 is extended through the brush 255, the armature 221 and its contact at rest, to short-circuit the relay 203 and prevent its attraction. The occupancy relay of all feeders 208 is kept attracted as long as a feeder has not become free again. The circuit for maintaining the occupancy relay of all feeders 208 in the drawn position is as follows: positive to the springs 124 of the occupancy keys in all free local connectors, shaft springs 122 of the free connectors, armature 117, common string 69, winding of relay 208, negative.

   We could mention at this point that the wires 260, 261 and 262 can, if desired, be extended to a group of relays allowing the connection of the operator control junction of an R.C.X. on a second R.C.X. identical.



   The relay 203 by attracting following the circuit described above at the armature 219 maintains the occupancy relay of all the feeders 208 in the drawn position, at the armature 220 it closes the attraction circuit of the control electro 64 of the pre-selected feeder, at armature 221 it opens the circuit to attract the electricity.

  <Desc / Clms Page number 8>

 command tro 253 and prepares at one point the circuit of relay 103 and relay 104 of the local connector, the armature 222 closes the circuits of the relays 217 and 203 and the armature 223 it loops the test circuit through the winding of relays 206 and 207.



   Relay 206 attracts via armature 218, before slow pulling relay 217 has drawn fully, it attracts its weighted armature 226 to close springs 286 and 288, thereby establishing the relay circuit slow . release 204. At frame 225 the re-
 EMI8.1
 Here 204 closes its 4Lndéuendemri-.ent blocking circuit of the springs 286 and at the armature 216 it opens at a point the circuit leading to the control electro 253 before the slow relay 217 has closed its armature 224. The slow relay 217 by attracting, the armature 224 prepares the circuit of the control electro 253 and the armature 218 opens the circuit of the relay 205.

   The relay 205 releases its weighted frame 226 which vibrates between the springs 207 and 208 to keep the slow relay 204 attracted for a determined period. This period is approximately 4 seconds or sufficient time to associate the calling line =. a free feeder.



   The circuit for attracting the control electra 64 of the preselected feeder is as follows:
 EMI8.2
 positive by ird, Gl.'l1, ú.J.iu.Íre du l '.. tl't:,:. 1.ture' ..: C ', r :. ture 22C, armature --2e and contact at rest, armature 227, brush 257 engaged on the contact of the bench where the preselected feeder ends, wire 67, winding of the control electro 54, negative. The electro of
 EMI8.3
 command 64 by pulling its pawl into position. of work to advance the researcher's brushes,

  <Desc / Clms Page number 9>

 and at armature 63 it grounds wire 66 to complete the circuit of advancement relay 206 in the distributor. This circuit closes as follows: positive to wire 66 through distributor bank contact, brush 256, relay winding 206, negative.

   At armature 227, relay 206, by attracting, opens the circuit of control electro 64 which releases. The electro 64 by releasing, advances the searcher brushes by one step and at the armature 63 opens the circuit of the advance relay 206. The relay 206 releases and at the armature 227 closes the circuit of the electro 64. This interaction between the electro 64 and the relay 206 continues until the researcher's test brush 61 meets the marking polarity applied to the bench contact of the calling line.



   When the seeker's brush 61 meets the calling line marking polarity, relays 206, 207 and 12 draw in series in the circuit: positive through wire 260, armature 223, lower coil of relay 206, upper coil of test relay 207, brush 258, wire 68, brush 61 engaged on the third contact of the bench, wire 24, armature 13 and winding of the cut-off relay 12, negative. Relay 206 is kept attracted along this circuit to open the circuit from electro 64 to armature 227.

   The cut-off relay 12 by attracting to the armature 16 opens the original circuit of attraction of the line relay 11, to the armature 17 it connects its winding to the wire 24 independently of the armature 13, and to the armature 18 it opens the circuit of the start relay 201 and the blocking circuit passing through the lower winding of the line relay 11. The line relay 11 releases and at the armature 15 prepares the start circuit at one point.

  <Desc / Clms Page number 10>

 versation to the calling line.



   The test relay 207, by attracting, to the armature 228 opens at another point the attraction circuit of the electro 64 and closes the attraction circuit of the control electro 253 through the working contact of armature 220. At armature 230, test relay 207 puts wire 65 to earth to complete the attraction circuit of relays 103 and 104 of the local connector. At armature 231 it closes its blocking circuit through its lower winding and wire 264 grounded, at armature 232 it opens the circuit of relay 203 and at armature 232 and its contact at work it closes the attraction circuit of the relay 430. The starting relay 201 releases when its circuit is opened by the relay 12 and at the armature 212 it opens the circuit of the relay 202 which releases.

   At armature 213, relay 201 opens at another point the circuit of relay 203. Electro 253 attracted as a result of the operation of test relay 207 and places its pawl in the working position for the advancement of the distributor brushes. At the switching springs 254, the control electro 253 opens the circuit of relay 203 at another point.



   The relays 103 and 104 of the local connector attract according to the circuit: positive to the armature 230, contact to the work of the armature 221, brush 255, wire 65, springs 123 of the occupancy key, shaft springs 125 and contact at rest, winding of relay 103, negative and via the normally closed springs controlled by armature 140 through the winding of relay 104 and negative. At armatures 115 and 119, relay 103 prepares the conversation circuit to the calling line, at armature 117 it disconnects one of the

  <Desc / Clms Page number 11>

 multiple positive of the chain wire 69, at the armature 118 it closes its own blocking circuit at the armature 112 earthed; armature 116 connects armature ground 155 to connector blocking wire 68 to keep calling line circuit cut-off relay 12 engaged.

   At armature 120, relay 103 opens at one point the circuit of electro release 109. Relay connector 104, by attracting, to armatures 127 and 137 connects the calling line to conversation wires 268 and 269 of the equipment. common, to the frame 128 it connects the negative ringing wire 187 to the brush 151, to the frame 136 it connects the positive ringing wire 188 to the brush 154; the armature 129 it connects the positive to the brush 152; at armature 130 he prepares the circuit of electro-ascension 111, at armature 131 11 prepares the circuit of relay 105; at armature 134 he prepares the circuit of the electro of rotation 110; at armature 135 it prepares the circuit of release relay 102 and at armature 132 it prepares the circuit of relay 106.



   The relay 203 releases after a while and at armature 219 removes one of the positives of wire 69.



  At armature 220, relay 203 opens the circuit of electro 253 to release it. At armature 221 it closes the preselection search circuit to allow the distributor to preselect a free junction; at armature 222 it opens the circuit of relay 217; and at armature 223 it opens the test circuit at one point. The electro 253, by releasing, advances the brushes, 255 to 258 inclusive, of the distributor by one case and closes its switch springs 254 to complete the preselection circuit which will allow the distributor to preselect a free feeder.

   In the event that the broom 255

  <Desc / Clms Page number 12>

 is engaged on its bank contact where the ground wire of an occupied feeder ends, this wire is earthed and therefore a clean control circuit closes for the electro 253 as follows: positive on contact with the bank on which the brush 255 is engaged, armature 221 and contact at rest, switch springs 254, winding of the electro 253, negative. The electronic control 253 operates as a buzzer as long as the brush 255 remains engaged on grounded bank contacts, it stops when the brush 255 no longer encounters a grounded contact.

   Since all busy feeders have their ground wire, such as wire 65, grounded, the 253 electro will continue to advance the distributor brushes until the 255 brush stops on a bank contact. which ends with a wire 65 not connected to earth. Relay 217 releases after a while and armature 218 prepares the circuit for relay 205. Relay 204 also releases after a while when weighted armature 226 stops vibrating between springs 286 and 288.



   At this point of the description, it is undoubtedly interesting to describe the operation of the delayed release device when, as a result of any fault, a searcher cannot find the calling line.



  In this case, as a result of the fault, the relay 207 does not attract and after a determined period the relay 204 releases, at the armature 216 it causes the control electro 253 to be attracted by the intermediary of the armature 224. The electro 253, with the switching springs 254, opens the circuit of the relay 203 which therefore releases. At armature 222, relay 203 opens the circuit of relay 217 which releases and at armature 224 it opens the circuit of electro 253

  <Desc / Clms Page number 13>

 to cause the search for another free feeder.



   Relay 430 attracts as a result of operation of test relay 207 following the circuit: to wire 262, armature 232 and contact on, armature 252, wire 263, normally closed springs controlled by armature 437, winding of relay 430, negative . At armature 432 relay 430 opens the loop of wires from control junction 451 and 452 to the far center and at armature 433 completes the pull circuit of slow relay to pull 431 as follows: Armature 433, Wire 291, Armature 289, Wire 290, Relay Winding 431, Negative.

   At armature 434, relay 431 prepares the circuit of relay 303 at one point, at armature 439 it closes the circuit of the emergency control device E.O.S .; at reinforcements 435 and 436 it disconnects the supervision switch; at armature 438 it locks to grounded wire 264 via wires 291 and 290, at armature 437 it opens the circuit of slow relay on release 430; at armature 441 it prepares at one point the circuit bypassing the right-hand winding of the translating coil RC1 of the common equipment.



   Relay 470 at the remote control center is normally energized by the control junction as follows: positive through the lower windings of relays 302 and 301, wire 271, lower left winding of the RC1 translator coil, wire 452, lower right winding of the translator coil RC2, upper winding of low resistance of relay 470, lower winding of high resistance of relay 470, resistance R, on contact and armature 372, normally closed contacts controlled by the springs of key 462,

  <Desc / Clms Page number 14>

 top winding of translator coil RC2, wire from junction 451, armature 432, top left winding of translator coil RC1, wire 270, top windings of relays 301 and 302 in series, negative.



  As a result of the introduction into the circuit of the resistor R and the high resistance of the winding of the common relay 470, the line relay 302 of the equipment does not draw. Furthermore, the relay 301 being a differential relay does not attract according to this circuit. Relay 470 at the remote control center drops when relay 430 at armature 432 opens the circuit described above. At the armature 472 the relay 470 interrupts its own circuit and substitutes the relay 471 which draws in the circuit of the control junction when the relay 430 releases, which it does a little after the relay 431 has opened its circuit to the armature 437. The relay 430 by releasing, to the armature 432, through the control junction, closes the attraction circuit of the relay 471 through the armature 472 and its contact at rest.

   At armature 475, relay 471 closes the lamp ignition circuit 474 to alert the operator of the remote office, the operator circuit being marked 0.



  In addition in the event that the night alarm key NA is closed, as shown in the plan, releasing the relay 470 to the armature 473 closes the supply circuit of buzzer B which operates to attract the attention of the operator.



   When the lamp 474 comes on, the operator operates the key K to connect her station to the terminals of the left windings of the translating coil RC2 by means of the springs 460 and 464. The operation of the key K opens also the relay circuit 471 to the normally closed contacts controlled by the springs 462 and

  <Desc / Clms Page number 15>

 plus replaces the lower strength upper winding
 EMI15.1
 Lunau du roluis 470 mt ruiuin = L "l1. The roiais 470 is, supplied through the windings of the line relay 312 of the common equipment according to the circuit described previously, through the straight windings of the translator coil RC2 and the upper winding of the relay 470, by means of the springs 461, the impulse springs 469 of the call device CD, the spring 462 and its contact to work.

   At armature 472, relay 470 opens at another point the circuit of relay 471 and at its working contact prepares the circuit inserting resistance R and the lower winding of high resistance in series with the control junction when the key K is returned to rest. At armature 473, relay 470 opens the buzzer circuit.



   In the event that the call comes from a prepaid station a group of tone relays (not shown) is put into service, it connects a special tone to wire 270.



   If another subscriber connected to the RCX made a call the start relay 201 and the relay 202 would operate in the same way as previously described, and in this case the intermittent operation of the relay 202 connects the positive through the armature. 214 and resistance to wire 270 to alert the attendant that a second call is pending. In the application described here the dial tone is connected as soon as the call is made.



   When the low resistance top winding of relay 470 at the remote office is connected to junction wires 451 and 452 as a result of the K key operation, line relay 302 draws through wires 270 and 271 in the circuit described above. AT

  <Desc / Clms Page number 16>

 armature 317 relay 302 disconnects the positive of wire 277 and at armature 318 completes the attraction circuit of slow release relay 305. At armature 322 relay 305 earths wire 278 and completes the attraction circuit of the slow release relay 306. At armature 323, relay 305 prepares the pulse circuit at one point and at armature 326 it maintains wire 264 to earth.

   At armature 325, relay 306
 EMI16.1
 prnpnrc on a point 1? ;; l1ir (, lIitr end c; nrnxir5n nt rla liIJ.- ration, at armature 327 it grounds the tone start wire and blocking wire 390, at armature 328 it grounds the wire start of the call machine and removes one of the positives of wire 264; finally at armature 330 it opens at one point the original circuit of attraction of relay 203.



   All the operations which have just been described result from the fact that a call has been made and that the operator of the remote office has applied her disk key and answer K. The operator answers the call and takes note of the call. requested number. The conversation circuit between the calling subscriber and the operator is as follows: calling line and line wires 22 and 23, brushes 60 and 62, wires 72 and 73, armatures 115 and 119, armatures 1.13 and 147 and their contacts at rest, armatures 127 and 137, wire 185 and 186, contacts at rest and armatures 329 and 331, wires 268 and 269, translator coil RC1, wires 451 and 452, translator coil RC2, key springs 460 and 464, switch station circuit the operator. After having taken note of the requested number, the operator transmits the first digit of the requested number using the calling device.

   The springs 465 to 468 inclusive close as soon as the calling device starts and remain operated until it has resumed its rest position. Springs 465 and 466

  <Desc / Clms Page number 17>

 close the shunt circuit of the lower left winding of the RC2 translator coil and the shunt springs 467 and 468 close the short circuit of the upper coil of the relay 470 to improve the pulse circuit. This short circuit passes through the left terminal of the top winding of relay 470, springs 461, shunt springs 468 and 467, key springs 463, and the right terminal of relay 470. Pulse springs 469 of the call device CD are connected in parallel on the junction as follows: key springs 462, impulse springs 469, shunt springs 468 and 467, key springs 463.



   As a result of the operation of the impulse springs 469 the circuit which through the control junction leads to the relays 301 and 302 is opened at each of the
 EMI17.1
 impula-tono of the emitted cipher, the rolaja of line 302 releases with each impulse and to the armature 318 connects the impulse circuit to the series relay 311 and the ascension electric in parallel, as follows: through the armature 318 and its contact at rest, armature 323, armature 348 where the circuit is divided, one branch borrows the winding of the slow series relay on release 311 and the negative, the other branch borrows the armature 353 and its contact at rest, the wire 190, the armature 130, the winding of the ascension electro 111 and the negative.

   The relay 311 being slow to release is kept attracted during the period of sending the pulses and at armature 349 it short-circuits the right winding of the translator coil RC1 via
 EMI17.2
 'you thread 2C, () and. do the armaturu 'il. With the arineituro 350 10 ro- au lais 311 disconnects the positive of wire 189 and / contact to the work of the armature 350 it completes the circuit of attraction of the relay 312 through the armature 352

  <Desc / Clms Page number 18>

 and its contact at rest. At armature 351, relay 312 closes the short-circuit of relay 313 as follows: positive through armature 350 and its contact on, armature 352 and contact off, winding of relay 313, armature 351, blocking wire grounded 390.



   The ascension electro 311 raises the brushes 151 to 154 inclusive, by one step for each pulse received, so it brings the brushes of the local connector in front of the level of the bench where the called line ends. At the first step of ascent of the brushes the shaft springs 125 put the ground wire 65 and open the original circuit of attraction of the relays 103 and 104 which now remain attracted by the armature 112. The springs of shaft 122 operate on the first step of ascent of the brushes to open the chain wire grounding circuit at another point 69. Shaft springs 121 also operate on the first step of ascent of the brushes to open the circuit of the liberation electro 109.



   After the period of sending the pulses, the slow release relay 311 releases and the armature 350 opens the short-circuit of the winding of the relay 313 which has the effect of causing the relay 313 in series with the relay 312 through blocking wire 390 grounded. At armature 352, relay 313 opens the original circuit for attracting relay 312 which now remains attracted in series with relay 313 and when it is on contact it prepares the circuit for relay 314. At armature 353, relay 313 transfers the pulse circuit of the ascension electro 111 to the rotation electro 110 and to the armature 354 it prepares the circuit of the supervision electro 401 at one point.



   Under the action of the impulses of the second train the

  <Desc / Clms Page number 19>

 line relay 302 releases again on each pulse and on each release transmits a pulse to the series relay 311 following the circuit described previously and to the rotation electro as follows: positive to armature 318 and its contact at rest, armature 323 , armature 348, armature 353 and contact on, terminal 9, dotted line connecting terminal 9 to terminal 10, wire 195, armature 134, rotation electro 110, negative ... The rotation electro turns the connector brushes local in the bank to the contacts where the called line ends.

   The relay series 311 attracts again during the sending of the impulses and to the armature 350 disconnects the positive of the wire 189 and of the brush 152 during the rotational movement, in contact with the work of the armature 350 it completes the circuit of attraction of relay 314 as follows: positive to armature 350 and its contact on, armature 352 and contact on, armature 353, winding of relay 314, negative. At armature 356, relay 314 closes the short-circuit of the winding of relay 315 from the grounded blocking wire 390 to the grounded armature 350. After sending the pulses the relay Series 311 releases and armature 319 removes the short circuit of the RC1 translator coil.

   At armature 350, relay 311 puts wire 189 to earth to complete the circuit for attracting the cutoff relay, such as cutoff relay 12, of the called line; its contact on, it removes the short-circuit of relay 315 to allow the attraction of relay 315 in series with relay 314: The attraction circuit of relay 315 is as follows: positive to the blocking wire grounded 390 , armature 356 and contact on, winding of relays 315 and 314 in series, negative. At armature 357, relay 315 opens at one point the original circuit of attraction of the

  <Desc / Clms Page number 20>

 relay 314 and armature 358 it completes the attraction circuit of relay 307 as follows: positive to armature 358, armature 320, winding of relay 307, negative.

   The circuit for attracting the cut-off relay of the called line is as follows: positive at armature 350 and contact at rest, wire 189, armature 129, brush 152, test contact of the called line, winding of the cut-off relay identical to cut-off relay 12, negative.



  The cut-off relay of the called line, attracting, to the upper armature corresponding to the armature 16, opens the circuit of the line relay; at its lower armature corresponding to armature 18 it opens the starting circuit at one point and at its median armature corresponding to armature 17 it earths the searcher bench and corresponding connectors to occupy the line in these switches.



   Relay 307, pulling, to frames 329 and 331 disconnects the conversation wires, terminating at the calling line, from wires 268 and 269 and connects conversation wires 268 and 269 to ring positive and negative wires 187 and 188 to provide a listening circuit which will allow the attendant to see if the called line is free or busy. The attendant is now connected to a conversation circuit at the same time as the called line, as follows: contacts of the called line, brushes 151 and 154, armatures 128 and 136, positive and negative ringing wires 187 and 188, contacts on work and reinforcement 329 and 331, wires 268 and 269, right winding of the RC1 translating coil.

   The voice frequency currents are induced, through the left windings of the RC1 translator coil, in the wires of the junction 451 and 452 towards the right windings of the RC2 translator coil at the far center from where these

  <Desc / Clms Page number 21>

 currents are retransmitted through the left windings of the RC2 translator coil through the key springs 460 and 464 to the operator's station, If the called line is busy and if it is part of a group of lines having the same call number, the operator emits the number 1 and the rotary switch 110 moves the connector brushes to the next line. The attendant resumes listening and continues to send the number 1 until a free line or the last line of the group is reached.



  In the event that the attendant does not hear speaking, she will announce herself to determine whether the line is in service or not. If the attendant receives no response, she will then send the ringing code of the called subscriber.



   If the line is busy, the attendant will momentarily operate the two-position key to the control position to cause the pulling of the differential relay 301 of the common equipment. As a result of this operation the lower winding of the relay 301 is short-circuited which has the result of attracting co relays. The circuit; bypassing the lower winding of relay 301 is as follows: positive to key springs, springs 463, lower right winding of RC2 translator coil, wire 452, lower left winding of RC1 translator coil, wire 271, lower relay winding differential 301, lower winding of line relay 302, positive.

   Line relay 302 is kept attracted by its top winding and differential relay 301 by pulling to armature 316 grounds wire 275 to complete the pull circuit of relay 303 through armature 434 and his contact at work, wire 274,
 EMI21.1
 1 '; a rmW, uro aï (he do uon oontejrb un ropoa, do onroulumont

  <Desc / Clms Page number 22>

 relay 303 and negative. At armature 319, relay 303 short-circuits relay 304 as follows: positive to armature 316 and circuit described previously, armature 321 and contact at rest, winding of relay 301, armature 319 and blocking wire 390 on. To the earth. By returning the key to two positions in the normal position, the short-circuit of the lower winding of the differential relay 301 is eliminated, the latter therefore releasing.

   In frame 316, relay 301 disconnects the positive of wires 275 and 274 to eliminate the short circuit of relay 304, this draws in series with relay 303 and the grounded blocking wire 290. At armature 321, relay 304 opens the original circuit of attraction of relay '303 and when it contacts to work it prepares the circuit of bell relay 308, at armature 320 it opens the circuit of relay 307. The relay 307 releases and to its frames 329 and 331 reconnects the conversation threads 268 and 269 associated with the control junction to the conversation threads of the calling line. The attendant then informs the caller that the called line is busy.



   If the line is free, the operator operates her key in the control position, which has the effect of attracting relays 301, 303, 304 and 307 as has just been described. The operator then operates the two-position key in the call position depending on the school of the called subscriber. The differential relay 301. Each operation of the key to the call position, it --and wires 270 and 271 to earth as described previously.

   On each attraction of the differential relay 301, the latter to the armature 316 places the wires 275 and 274 to the ground through the intermediary of the armature 434 from which the circuit is extended through the armature. 321 and its contact at work, via terminal 6, the dotted line, terminal

  <Desc / Clms Page number 23>

 5, winding of bell relay 308 and relay 309 in parallel to negative. The bell relay 308 attracts each time the key is put in the call position while the slow release relay 309 remains attracted during this period.

   Each time the bell relay 308 pulls the called subscriber's calling circuit closes at armatures 338 and 341 as follows: generator wire G, wire 75, contact on and armature 338, terminal 1, dotted line, terminal 2, wire 187, armature 128, brush 151 engaged on the bench contact of the called line, called subscriber line, ringing, positive line wire, brush 154, armature 136, wire. 188, terminal 3, dotted line, terminal 4, armature 341 and contact on, wire 76 and return wire to generator G.P ..

   At armature 335 the ringing relay 3 08 prepares the attraction circuit of relay 106 used for communications between two stations connected to the same shared line and for long distance communications, at armature 333 it completes the circuit of attraction of the relay 310, and to the reinforcements,: j "5 nt 339 he closes the ringing tone and ringing for the calling subscriber and for the operator. The ringing circuit for the The operator is as follows: wire coming from the generator, wire 75, tone C capacitor, armature 336, wire 268, and then the circuit described previously, through the translatrioe coil RC1 to wire 269, armature 339, the capacitor tone C 'and the return wire to the generator.

   Return tone `` the call to the caller travels the circuit: Tone C capacitor, armature 336 and idle contact, wire 185, armature 127, armature 143, armature 115, loop of the calling line, wire 73, armature 119, armature 147, and idle contact, armature 137, wire 186, armature 331, armature 339, tone capacitor C '.

  <Desc / Clms Page number 24>

 



   If for the needs of a previous communication, another connector was brought to the base contacts of the called line and if the subscriber neglected to summon the end, the first pulse sent by the generator to
 EMI24.1
 the called line has the effect of doing it to alternating current 107 of this connector to operate the release. The circuit for attracting relay 107 of this connector is as follows: negative on the contacts of.
 EMI24.2
 bench of the called line, broom 151, armatures144 and 138, upper left winding of the RC translating coil, winding of relay 107, lower left winding
 EMI24.3
 of the translator coil t3C, armature 146, brush 1-4, positive in contact with the bank of the called line.

   The relay 107 from the connector not released to the armature 148 closes the attraction circuit of the relay 102 which causes the release of this other connector in a manner which will be described in more detail below.



   Relay 309 due to its release delay remains attracted during the period of sending inrush current, to armature 343 it connects the positive through the two left windings of the RC3 translator coil to connect the positive to the negative and positive bell wires 187 and 188 when the bell relay 30 @ is released in order to discharge the capacitors of
 EMI24.4
 ringing asscciàs ¯ the liana called. At the / ::: 'l,.' 21:,; u.re 0 - ..: ':; ; .ra.Him = su <J <iàc <> i ,,, a,: L, a JL't: if.t'u! .tt '! t ..' t:!.

   Jl'uLI t. [, Read .... m "translator RC. The relay 310 by attracting to the armature 345 prepares at one point the three-way conversation circuit for the calling party, called party and operator; at armature 346 it prepares at one point the conversation circuit and the circuit allowing the positive of armature 343 to discharge the ringing capacitors associated with the called line; at armature 335 it prepares wax at one point. 1 =

  <Desc / Clms Page number 25>

 of relay 105; at armature 347 it completes its blocking circuit at armature 327 earthed; finally at armature 348 it opens the pulse circuit at one point.



  Each time the two-position key is put in the call position it will cause the pulling of the differential relay 301 and the bell relay 308 to call.
 EMI25.1
 1 <.I;:, lr.v5; juivunL sun oude j,> ruj¯ira, lia little Ujjrùs read period of sending of the inrush current relay 309 releases, at armature 342 it completes the three-way circuit between the two subscribers and the operator of the remote office as follows: conversation circuit between the calling subscriber and the operator is the same as that which has been described previously; one branch of this circuit is extended by the wires 268 and 269 through the right windings of the translator coil RC3.

   The vocal frequencies currents are induced in the left windings of the RC3 translator coil and from there are sent through the wires in reinforced lines, armatures 389, and 341, wires 187 and 188, armatures 128 and 136, brooms 151 and 154 and wires from the called line to the station.



   The attendant can wait until the called subscriber has answered or can disconnect from the control trunk and release the common equipment without waiting for the called subscriber to answer. Assuming that the attendant waits for the called subscriber to answer and to ensure that the conversation is initiated, she returns the key K to the normal position to release the common equipment which. by freeing itself a new conversation circuit is established between the calling and called subscribers. By setting the key K to rest, the springs 460 and 464 disconnect the operator's station and the springs 462 and 463 reconnect the two windings of the relay 470 and the

  <Desc / Clms Page number 26>

 resistor R bridging wires 270 and 271 to release line relay 302.

   Line relay 502 when releasing, at armature 318 opens the circuit of slow relay on release 305. Relay 305 releases after a moment and at the NO contacts of armature 322 disconnects the positive of wire 278 and opens the relay. relay 306 circuit, when it comes into contact with the meal it momentarily earths wire 191 to cause the attraction of relay 105. At armature 326 relay 305 disconnects the positive of wire 264 to release relay 207 and
 EMI26.1
 the ralcis 431. The rolaio 207 on releasing Il the o.r:, (1, '11 ". 228 prepares the circuit of the control electro 64; at the armature 231 it opens at one point its own circuit of blocking, and at armature 232 it grounds wire 273 to prepare the circuit for relay 203.

   Relay 431 on releasing armature 434 disconnects wires 274 and 275; at armature 441 it disconnects wires 266 and 268; at reinforcements 435 and 436 it reconnects the supervision switch to wires 268 and 269; at armature 438 it opens its own blocking circuit at one point and at armature 437 it prepares the circuit of relay 430 at one point.



   The circuit for attracting relay 105 after releasing relay 305 is as follows: positive to armature 322 and its contact at rest, armature 325, armature 355 and contact on, wire 191, armature 131, winding of the relay 105, negative. To the armatures 133 and 142 the relay 105 connects the right windings of the translator coil RC to the calling line; to armature 138 it connects the left windings of the translating coil to the called line; on the armature 139 it puts the brush 152 to the ground to maintain the cut-off relay
 EMI26.2
 12 of the called line in the drawn position; at armu'.ure 140 it completes its blocking circuit specific to arma-cure

  <Desc / Clms Page number 27>

 
112 earthed, it also opens the circuit of relay 104 which releases;

   at armature 141 it prepares the circuit of relay 102; at the armature 155 it disconnects the direct positive from the wire 68 and substitutes a positive for it through the winding of the marginal relay 170 to maintain the cut-off relay 12 of the calling line in the drawn position; at frame 145 it prepares a circuit used for the establishment of long distance communications.



   Releasing relay 104, at its armatures, disconnects the common equipment from the local connection circuit. The calling and called subscribers are now connected to the following conversation circuit: calling line and circuit described previously using the wires marked in reinforced lines, reinforcements 115 and 119, reinforcements 143 and
147 and their contacts at rest, armatures 133 and 142, right winding of the RC translating coil. The called subscriber is connected to the conversation wires of his line to the brushes 151 and 154 and from there through the armatures 144, 138 and 146 through the left windings of the RC translator coil.

   The voice frequency currents are induced through the windings of the RC translator coil thus allowing the calling and called subscribers to converse together.



   The slow release relay 306 releases a little after the opening of its circuit caused by the release of the relay 305; at armature 325 it opens the original attraction circuit of relay 105 which is now blocked in the attracted position. At armature 327 the relay
306 disconnects the positive of the tone start wire @ TS and of the blocking wire 390 to cause the release of the relays 303,304, 310, 312, 313, 314 and 315. At frame 328 the relay 306 disconnects the positive from the relay. start wire of the call machine RMST and set wire 264 to

  <Desc / Clms Page number 28>

 Earth. At armature 330, relay 306 prepares the circuit for relay 203, at armature 332 it grounds wire 277 and brush 403 of the supervisory switch.



  The common equipment is released: - and can be used for another call.



   After the conversation and as a result of sending the terminating current by the calling party, relay 108 draws into the conversation circuit described above for the calling line. If the called party rings the end of the relay 107 draws into the conversation circuit described for the called line. As a result of the attraction of the relay 107 or of the relay 108, the attraction circuit of the relay 102 closes: on the armature 148 or 149 via the positive of the armature 141. The relay 102 by attracting to the armature 113 connects a multiple positive to relays 103 and 105 to keep it attracted; at armature 114 it grounds wire 74 and closes the attraction circuit of relay 101. Relay 101 at armature 112 disconnects one of the multiple positives keeping relays 103 and 105 attracted.

   After the end relays 107 and 108 have released and opened the circuit of the relay 102, the relay 102 releases and at the armature 113 opens the circuit of the relays 105 and 103 which also release; to frame It! it opens the circuit of the slow relay on release 101 which releases after a certain time. The relay 105 by releasing, at the armatures 133 and 142 disconnects the right windings of the translator coil RC, at the armature 138 it disconnects the left windings of the translator coil RC; at the armature 139 it disconnects the positive from the brush 152 to release the cut-off relay 12 of the called line; at armature 140 it opens its own blocking circuit at one point and prepares the attraction circuit of relay 104, at armature 141 it opens the circuit of relay 102.

   Relay 103, when releasing, to arma-

  <Desc / Clms Page number 29>

 tures 115 and 119 opens the circuit of the calling line; at armature 117, it prepares the chain circuit at one point towards the occupancy relay 208 of all the feeders; at armature 118 it opens its own blocking circuit at one point; at armature 116 it opens the circuit of cut-off relay 12 of the calling line which releases, at armature 120 it closes the circuit for attracting the release electro 109. The slow release relay 101 releases afterwards. a while, that's at. say after releasing the relays 103 and 105. As a result of the operation of the release electro 109 the switch brushes return to the normal position in the well known manner.

   The engagement springs 121 open when the brushes reach their rest position and open the circuit of the release electro 109. As a result of the resting of the engagement springs 125 the positive is removed from the wire. guard 65 to make this local connector free for selection and to prepare the attraction circuits for relays 103 and 104. Putting the springs to rest 122 puts the starter wire in chain 69 to earth to maintain the relay 208 of occupation of all feeders in the drawn position.



   In the circuit of the calling line the cut-off relay 12 releases, at the armature 16 it reconnects the line relay 11, at the armature 18 it reconnects the starter wire 30. In the circuit of the line called the relay of The cutoff releases and reconnects the line relay and the starter wire in an identical manner. The disconnect circuit is now free and can be used for another call.



   In the event that the attendant finds the called line occupied, she places her two-position key in the test position to disconnect from the called line and

  <Desc / Clms Page number 30>

 the to connect / control trunk to the calling line as previously described. The operator informs the calling subscriber that the line is busy and returns the K key to idle. In a manner identical to that which has been described above, putting the key K to rest causes the relays 502 and 305 to be released, which release the common equipment and the local connector.

   The release of lead 305, at this moment, since the call current has not been sent, closes the attraction circuit of the release relay 102 of the connector as follows: positive, armature 322 and contact at rest, armature 325, armature 355 and contact at rest, release wire, armature 135, winding of relay 102, negative. The relay 102 attracts and causes the release of the local connector in the manner already described. In the common equipment, the relay 305 causes the release of the latter as has been said above.



   Communication between two sets connected to the same shared line.



   To obtain a communication with a set connected to its own line, the caller will operate as described previously. When the attendant answers the call and realizes what the caller wants to talk to a subscriber on the same line as him, she asks the caller to hang up. The attendant then places her two-position key 3. in the test position and then in the call position and rings the called party according to her own code without sending any digit. The finder F, the distributor and the relays 103 and 104 of the local connector operate as described previously.

   Putting the two position key into the test position will ground control junction wires 451 and 452 as well as wires 270 and 271 to pull differential relay 301 as previously described. Relay

  <Desc / Clms Page number 31>

 differential 301 by attracting, to armature 316 completes the attraction circuit of relay 303 through wires 275 and 274. When the key leaves the test position the differential relay 301 releases and removes the short circuit of the relay 304 which therefore attracts in series with relay 303 as described above.

   The operator then places the two-position key in the call position and activates it according to the code of the called subscriber; therefore it causes the pulling of the differential relay 301 each time the key is put in the call position.



  Whenever the differential relay 301 pulls the bell relay 308 also pulls to send the inrush current to the calling line. Relay 309 draws in parallel with relay 308 and due to its delay in releasing it remains drawn during the send period.



  At armature 333 the relay 308, attracting for the first time, closes the attracting circuit of the relay 310 which attracts and blocks at the blocking wire 390. At armature 355 the bell relay 308, attracting for the first time, closes the local connector relay 106 attraction circuit as follows: to blocking wire 390, armature 356 and contact at rest, armature 335, wire 192, armature 132, winding of relay 106, negative.

   At armatures 338 and 341, relay 308 closes the circuit sending the ringing current to the calling line as follows: generator, wire 75, contact on and armature 338, terminal 1, dotted line, terminal 2, wire 187, armature 128, make contact and armature 143, armature 115, wire 73, 'broom 60, wire 22, calling line loop, wire 23, broom 62, wire 73, armature 119, armature 147 and contact at work, armature 136, wire 188, terminal 3, dotted line, terminal 4, armature 341 and contact on, return wire to generator 76. Relay 106, in

  <Desc / Clms Page number 32>

 attracting, at frames 144 and 146 disconnect the left windings of the translator coil.

   In reinforcements 143 and 147, it completes at one point the circuit for sending the inrush current to the calling line as has already been described. Relay 309 by pulling armature 343 discharges the ringing capacitors of the calling line during the silent period when ringing relay 308 is in the released position. When the calling and called subscribers answer the operator straightens the key K, thereby relays 302 and 303 release in the manner already described. At armature 322, relay 305 completes the attraction circuit of relay 105 of the connector as follows: positive ù armature 322 and its contact at rest, armature 325, armature 355 and contact on, wire 191, armature 131, winding of relay 105, negative.

   At armature 326, relay 305 opens the circuit of relays 207 and 431 to cause their release; to armature 322 and on contact it closes the circuit of relay 105.



  The relay 105 by attracting the armature 140 again closes its blocking circuit and opens the attraction circuit of the relay 140 which releases. To the armatures 133 and 142 the relay 105 prepares the circuits connecting the right winding of the translator coil RC to the calling line.



  Relay 104 by releasing disconnects the local connector of the common equipment and at armature 132 opens the circuit of draw of relay 106. Relay 106 by releasing at armatures 143 and 147 and at the rest contacts connects the right winding of the relay. RC translator coil at the calling line. In the common equipment relay 306 releases after a certain time and at armature 327 opens the circuit of relays 303, 304, 310, and 106.



   At the end of the communication when the calling party rings the end, relay 108 draws into the circuit

  <Desc / Clms Page number 33>

 of the calling line, at armature 149 it closes the attraction circuit of relay 102 which takes a positive at armature 141. At armature 114, relay 102 completes the attraction circuit of relay 101 and at armature 114 armature 113 it closes a blocking circuit on positive of all relays 103 and 105 which are attracted. The relay 101 by attracting to the armature 112 opens one of the positive circuits of the relays 103 and 105. When the end is sounded the relay 108 releases and to the armature 149 opens the circuit of the relay 102 which releases. At armature 113, relay 102 opens the circuits of relays 103 and 105 which release, at armature 114 it opens the circuit of relay 101 which also releases after a certain time.

   The relay 103, by releasing the armatures 133 and 142, disconnects the translating coil from the calling line. The relay 103, by releasing the armature 118, prevents the earthing of the guard wire 65, the positive of which had been removed following the release of the relay 102; at armature 117 it puts wire 69 to earth to keep relay 208 in the drawn position and at armature 116 it disconnects the positive through the winding of marginal relay 170 from wire 68 to release the cutout relay 12 of the calling line. The cutoff relay 12 on releasing reconnects the line relay and the starter wire as already described. Local battery lines with earth return make and receive calls as described above.

   The RC3 translator coil of common equipment allows a line having its negative wire grounded to converse with a line having its positive wire grounded, if it were otherwise two such lines interconnected by the common equipment would be shorted to ground, no conversation could take place until the operation.

  <Desc / Clms Page number 34>

 failure to disconnect the common equipment from the connector.



   Central battery subscriber lines can also be connected to this type of R.C.X. by making use of a line adapter such as the one shown in fig. 1 and including relays 50 to 54 inclusive. When a central battery subscriber, such as the one marked S, picks up relay 50 draws into the line circuit, as follows: positive and lower winding of relay 50, contact at rest and armature 56, armature 58 and contact at rest, loop of the calling line, armature 55 and closed contact, armature 57 and closed contact, upper winding of relay 50, negative. At armatures 90 and 91, relay 50 disconnects the alternating current relays 53 and 54, at idle contacts and at work contacts it prepares the conversation circuit at several points.

   At armature 59, relay 50 closes the attraction circuit of the slow relay on release 51. At armature 93, relay 51 closes the attraction circuit of the slow relay on release 52 and on armatures 92 and 94 momentarily. , it closes the line relay attraction circuit 31 through its upper winding, as follows: positive at armature 92 and working contact, idle contact and armature 96, armature 36, upper coil of the relay line 31, armature 35, armature 97 and contact at rest, armature 94, resistance 99, negative.



   Line relay 31 by drawing to armature 33 connects the inrush polarity, through the winding of cutoff relay 32, to the researcher bench; to the frame
34 it hangs on the starter wire 20 and causes the attraction of the starter relay 201; at armature 35 it opens its original attraction circuit at one point after it has blocked. The slow relay at attraction 52 attracts after a while, at frames 96 and 97 it

  <Desc / Clms Page number 35>

 opens at one point the original line relay attraction circuit 31.

   The sequence of operations from this moment is the same as that described for a local battery line, the conversation circuit borrows the lines in reinforced lines through the line adapter, as follows: 90 and 91 and their contacts at work, capacitors C and C ', contacts at rest and armatures 57 and 56, armatures 55 and 58 and their contacts at rest, calling party loop. The supply current for the caller is given through the windings of the relay 50. At the end of the communication when the caller hangs up the relay 50 releases and at the armatures 90 and 91 open the conversation circuit. At armature 59, relay 50 opens the circuit of slow release relay 51 which releases after a certain time.

   Relay 51 at armature 93 opens the circuit of relay 52 which releases after a certain time since relay 52 is slow to release as well as pull. At armatures 92 and 95, relay 51, releasing before relay 52 attracts, momentarily connects the positive and negative to the wires of the LC - 1 line to cause the attraction of the relays, such as 107 or 108, from the connector in service to cause its release.

   The attraction circuit of relay 108 of the connector is as follows: positive at armature 92 and contact at rest, contact on work and armature 96, reinforced line of the conversation circuit of the LC - 1 line, finder brush 60 , wire 72, armature 115, armature 143 and contact at rest, armature 133, upper right winding d, e translator coil RC, winding of relay 108, lower left winding of translator coil RC1, armature 142, contact at rest and armature 147, armature 119, wire 73, brush 62 engaged on the fifth contact of the bench, armature 35, armature 97 and contact at work, armature 95, resistance 98, negative.

   As a result of the stattrac-

  <Desc / Clms Page number 36>

 When relay 108 is released, the connector is released as described above.



   In the case of a call to a central battery line, the operations are identical to those which have already been described. In the case where the bell of the central battery station called is bridged on the line wires or connected between the negative wire and the earth, the inrush current is sent to the retort wire described above and, through the intermediary of the armature 90 and the contact at rest, through the winding of the alternating current relay 53 towards the positive. AC relay 53 draws along this circuit and to armatures 57 and 58 and their idle contacts disconnect relay 50, thereby reducing the impedance of the inrush circuit to the called line.

   To armatures 57 and 58 and their contacts at work, the alternating current relay establishes the inrush circuit through armature 55 through the rings and the positive to armature 58 in the case where the rings are bridged on the line wires or against the bells and ground taken at the stations themselves in the case where the bells are connected between the negative wire and the ground taken at the stations. when the called subscriber answers the circuit described above for the attraction of the relay 50 closes during the first period of silence when the relay 53 is attracted. Relay 50 to armatures 90 and 91 completes the conversation circuit and armature 59 attracts relay 51.

   The relays 51 and 52 attract in the same way as that which was previously described but in the present known case the cut-off relay 32 was attracted when the line was seized, the line relay 31 does not attract when the positive and the negative are momentarily connected to the line wires. To the

  <Desc / Clms Page number 37>

 end of communication when the called party hangs up relays 50, 51 and 52 release as described above and momentarily close the relay attraction circuit, such as relay 107, of the local connector to cause the release of the latter as a result the momentary connection of a positive and a negative to wires 39 and 40. In the case where the bell of the called station is connected to the positive wire, the inrush current is connected to wire 41 as described below for the split call.

   In this case the inrush current is established, via the armature 91 and the contact at rest, through the winding of the alternating current relay 54 towards the positive to cause the attraction of this relay to each application of the inrush current to the wire 41. At the armature 56, the relay 54 completes the circuit passing through the contact at rest and the armature 58 to activate the bells connected between the positive wire and the earth. During a period of silence and when the called party answers the relay 50 draws into the circuit of the called line, it completes the conversation circuit as described previously.



   Long distance communications.



   To establish a long distance call to a subscriber connected to the R.C.X. the operator of the long distance office pushes the plug of a cord circuit into the jack J. Following the insertion of the plug into the jack J the springs 521 close the attraction circuit of the relay 503 as follows:

   positive through lower winding of relay 503, lower winding of differential relay 504, lower left winding of RC5 translator coil, idle contact and 527 armature, wire 591, lower right winding of RC4 translator coil, 521 jack springs , upper right winding of the RC4 translator coil, wire 590, armature 525 and contact at rest, in-

  <Desc / Clms Page number 38>

 RC5 translator coil upper left bearing, differential relay 504 upper coil, line relay 503 upper coil, negative. Line relay 503 attracts in the circuit described above but differential relay 504 does not attract because its two windings: slow are equal and work in opposite directions.

   At armature 531, relay 503 closes the attraction circuit of the slow release relay 502. At armature 528, relay 502 prepares the circuit of the upper winding of relay 503, at armature 529 it closes the circuit for attracting relays 506 and 508 as follows: positive to armature 529 and contact on, normally closed springs controlled by armature 538, armature 545 and contact at rest, windings of relays 506 and 508 in parallel, negative. At armature 534, relay 506 short-circuits the right winding of the translator coil RC5 to avoid noise in the operator's receiver.



  The relay 508 by attracting to the armatures 541 and 542 completes the attraction circuit of the line relay 511 of the trunk line circuit, as follows: positive at idle contact and at armature 537, on contact and armature 542, armature 563, upper winding of relay 511, armature 564, armature 541 and NO contact, armature 536 and contact closed, resistance 535, negative.



    At armature 543, relay 508 closes the attraction circuit of the slow release relay 507. The relay 511 by attracting to armature 561 connects the inrush polarity ¯. through the windings of the relays 509 and 512 to the terminals of the finder via the wire 165. At the armature 562 it locks itself to the common starting wire 30 and it causes the starting relay 201 to be attracted; at armature 563 it opens its original circuit of attraction at one point after its blocking circuit has been established.

   The slow relay at attraction 507 attracts after a while, at

  <Desc / Clms Page number 39>

 armatures 536 and 537 it opens the original line relay attraction circuit 511 and connects the generator to contacts 581 and 582 to release any connector which has its brushes engaged on these contacts. At armature 538, relay 507 completes its blocking circuit at earthed armature 529 and opens the circuits of relays 506 and 508 which release after a certain time. The relay 508 by releasing the armatures 541 and 542 disconnects the generator from the wires 161 and 164 and from the bank contacts 581 and 582, it connects the right winding of the translating coil R05 to the wires 161 and 164.



  At armature 543, relay 508 opens the original circuit of attraction of relay 507. Relay 506 by releasing at armature 534 removes the short-circuit of the right winding of translator coil RC5.



   The attraction of the start relay 201 causes the searcher to search for the trunk line in the manner which has been described previously; therefore relays 500 and 512 draw in series with relays 206 and 207 as follows: positive to wire 260, armature 223, lower coil of relay 206, upper coil of. test relay 207, brush 258, wire 68, brush 61, fourth bank contact, wire 165, armature 561, the circuit then splits, one branch goes to the cut-off relay 512 and the negative; the other branch goes through the armature 544 and the contact at rest, from the winding of the relay 509 towards the negative.

   Relay 512 attracting, at armature 564 disconnects line relay 511, at armature 565 it maintains its own circuit, at armature 566 it opens the starting circuit of relays 201 and the blocking circuit of relay 511 Line relay 511 therefore releases and armature 563 prepares the conversation circuit at one point. Relay 509, at the ar-

  <Desc / Clms Page number 40>

 nature 546, opens the relay 510 circuit to prevent the trunk line from being taken for a call.



  The attendant is warned as in the case of a local call and answers by operating the K key. A conversation circuit between the long distance operator and the operator of the control desk is established as follows: cord circuit and extension of the interurban operator, jack springs 522 and 523, translator coil RC4, wires 590 and 591, armatures 525 and 527 and their contacts at rest, translator coil RC5, contacts at rest and armatures 541 and 542, armature 563, wires 161 and 164, brushes 60 and 62 of seeker F, assuming that seeker F and the local connector of FIG.

   2 are part of the feeder that was entered for this call, wires 72 and 73, armatures 115 and 119, armatures 143 and 117 and their contacts at rest, armatures 127 and 137, wires 185 and 186, contacts at rest and armatures 329 and 331, wires 268 and 269, translator coil RC1, wires 451 and 452, translator coil RC2, key springs 460 and 464, operator's station.



   When the operator at the order desk answers, the long distance operator gives her the number of the desired subscriber. The operator of the order desk transmits the digits of this number and operates the local connector as has already been described. The emission of the digits of the called number causes the attraction of the relay 307 which disconnects the calling trunk line from the control junction and connects the called line in its place to allow the operator of the control desk to go coyote if the called line is free or busy.

   If the called line is free, the operator at the control desk first operates her two-position key in the test position to cause the attraction of the
 EMI40.1
 1 '() 11l1r; .liCT, 1 <.rnfiel; j01 and cht r'31o.is .j0 as 4Ç previously written.

  <Desc / Clms Page number 41>

 



   Returning the key to its normal position releases the differential relay 301 and allows the attraction of the relay 304 in series with the relay 303 as already described.



  Pulling relay 304 causes the relay to release
 EMI41.1
 507 which again connects the long distance operator to the operator at the order desk. The latter then operates the key in the call position according to the code of the called subscriber. Each time the key is operated in the call position, the differential relay 301 attracts and causes the attraction of the bell relay 308 which rings the called party as already described. When the called party answers the operator of the control desk withdraws from the communication by raising the key K and thereby causing the release of the relays 302 and 305 to attract the cut-off relay 105 of the local connector as described above.

   When relay 105 to armature 155 clears the short circuit of relay 170, the latter draws into the following circuit: coil of relay 170, armature 116, wire 68, brush 61, wire 165, armature 565, relay windings 512 and 509 in parallel.



   As a result of the increase in negative polarity across the two windings of relays 509 and 512 the marginal relay 170 attracts and transfers control of the connection from the local subscriber to the long distance operator. At armature 171, relay 170 closes the attraction circuit of relay 102 by means of the earthed armature 141, at armature 172 it completes the attraction circuit of relay 106 by means of the 'frame 141.

   The relay 106, by attracting to the armatures 143, 144, 146 and 147 disconnects the translator coil RC and connects the wires 72 and 73 directly to the brushes 151 and 154 thus completing a direct conversation circuit between the long distance operator and the line called independently of the RO translator coil.

  <Desc / Clms Page number 42>

 



   The relay 102 by attracting,. To the armature 113 keeps the relays 103 and 105 attracted, to the armature 114 it clamped the circuit of the relay 101. The relay 101, to the armature 156, partially short-circuits the winding. from relay 170 through resistor 173, this relay does not release at this time. When the called party rings the end of communication, the ringing current flows through the following circuit: brushes 151 and 154, contacts on and armatures 143 and 147, armatures 115 and 119, wires 72 and 73, brushes 60 and 62, wires 161 and 166, armature 563, armature 541 and 542 and contacts at rest, right winding of the RC5 translator coil, winding of relay 505. Relay 505 attracts under the action of the ringing current and at armature 533 closes the circuit. attraction of the 501 relay.

   At armature 526, relay 501 closes the blocking circuit of relay 503 through its upper winding, at armatures 525 and 527 and their working contacts it connects the incoming and return wires of the generator to wires 590 and 591 and by induction through the translator coil RC4 towards the cord of the interurban operator to give the latter the end supervision.



   The long distance operator can call back the called subscriber by operating his call key 524 which causes the attraction of the differential relay 504 since the lower winding of the differential relay 504 is short-circuited by the operation of the key 524. This circuit is as follows: positive to springs 524, upper right winding of the RC4 translator coil, 521 jack springs, lower right winding of the RC4 translator coil, wire 591, armature 527 and contact at rest, lower left winding of the coil translator RC5, lower winding of differential relay 504, lower winding of relay 503, positive.

   This positive continues on the upper thread

  <Desc / Clms Page number 43>

 conversation through key 524, wire 590 of armature 525, top winding of the translator coil and through the top windings of relays 504 and 503 to keep relay 503 attracted.



  Since the lower winding of differential relay 504 is shorted, relay 504 attracts. At armature 532, relay 504 closes the circuit for attracting relays 506 and 508 in parallel. At armature 534, relay 506 again short-circuits the translatrioe coil RC5; and relay 508 to frames 541 and 542 connects the incoming, DG, and return, GR1, wires from the generator to wires 161 and 166 to ring the called subscriber. Each operation of the key 524 therefore attracts the relay 504 and the relay 508 to connect the inrush current to the called line and to return the code specific to the latter.



   When she receives the end signal, the long distance operator removes the jaok J plug which separates the jack springs 521 and opens the attraction circuit of the relay 503. The relay 503 by releasing the armature 531 opens the circuit of the relay 502 which releases after a certain time. On armature 529 and on contact on, relay 502 opens the circuit of relay 507 which releases and on contact at rest of armature 529 causes relay 510 to momentarily attract. Relay 510 by attracting armature 544 puts the wire 165 to earth through the armature 565 and maintains the cut-off relay 512 in the operated position. At armature 544 and at rest contact, relay 510 opens the circuit of relay 509 which releases.



  After a while the relay 507 releases and at the armature 539 opens the circuit of the relay 510 which releases after a certain time. In the local connector the relay 170 is short-circuited by the direct positive connected to the wire 165 through the armature 544 which makes re-

  <Desc / Clms Page number 44>

 let go of this relay. After a while the relay 510 releases, removes the positive of the wire 165 and opens the circuit of the cut-off relay 512. At the same time in the local connector the relay 170 releases and at the armature 171 opens the circuit of the relay 102 which releases . At armature 172 it opens the circuit of relay 106 which releases.



  Relay 102 by releasing at armature 113 opens the circuit of relays 103 and 105 which consequently release, at armature 114 it opens the circuit of relay 101 which releases after a certain time; at armature 116 releasing relay 103 opens the circuit of cut-off relay 512 and relay 512 releases when relay 510 at armature 544 releases to open its circuit. The local connector now releases as described previously.



   It will now be assumed that a subscriber of R.C.X. wishes to obtain long distance communication. By making his call the subscriber of R.C.X. is connected to the control junction and the operator of the control desk is notified as described above. After having answered the call the operator of the control desk operates the connector to bring the brushes in front of the level of the trunk lines under the action of the characteristic pulses of the numbers corresponding to the groups of the trunk lines. If we assume that the local connector of fig. 2 is the connector put into service, it can be seen that when the brushes are brought in front of the interurban level, the springs 157 close.



  This action prepares the circuit of relay 106. In the manner described previously the operator rotates the brushes of the local connector to find a free trunk line in the group. Assuming that the trunk line of FIG. 6 is the one that is put

  <Desc / Clms Page number 45>

 in service, we see that when the series relay 311 of the common equipment releases after sending the pulses and puts the brush 152 to the ground, the attraction circuit of the relay 510 of the interurban junction closes as follows: positive to armature 350 and at contact at rest, wire 189, armature 129, brush 152, bank contacts 583, wire 162, armature 546, coil of relay 510, negative.



  At armature 544 the relay 510 completes the attraction circuit of the cut-off relay 512 of the trunk line circuit and at armature 545 prepares the circuit of relay 507. The relay 512, attracting, to armature 565 connects the positive through armature 544 to wire 165 to occupy this line at the researchers' benches. At armature 564, relay 512 disconnects line relay 511 and at armature 566 at one point opens the circuit for starter wire 30. The operator of the control desk now operates her key in the test position and then in the call position to attract relays 301, 303, 314 and 308 as described previously.

   As a result of the operation of the relay 308, the inrush current is connected to them sweeps 151 and 152 in the manner previously described by means of the armatures 541 and 542 and their contacts at rest and to the winding of the relay 505. The relay 505 attracts and to the armature 533 completes the attraction circuit of the relay 501. To the armatures 525 and 527 the relay 501 connects the inrush current to the wires of the interurban junction 590 and 591 and through the translator coil RC4 to make drop the DR valve to the position of the urban operator. After calling the long distance operator, the operator at the control desk returns her key to two idle positions, which stops sending the inrush current on the long distance lines and releases relay 505.

   Relay 505 when releasing opens the

  <Desc / Clms Page number 46>

 relay circuit 501 which also releases. In armatarés 525 and 527, relay 501 prepares the circuit of relay 503. When the valve falls, the long distance operator inserts the plug of a cord circuit in the J jack to remove the annunciator from the circuit and to raise the valve.

   On the springs of jack 521, the attraction circuit of relay 503 closes as follows: positive, lower winding of relays 503 and 504, lower left winding of the RC5 translator coil, contact at rest and armature 527, wire 591, lower right winding of the RC4 translator coil, jack springs 521, upper left winding of the RC4 translator coil, wire 590, armature 525 and contact at rest, upper left winding of the RC5 translator coil, upper winding of relays 504 and 503, negative. At armature 531, relay 503 closes the attraction circuit of relay 502.

   On armature 529, relay 502 completes the attraction circuit of relay 527 as follows: positive on armature 529 and on contact, normally closed springs controlled by armature 538, armature 545 and contact on, relay winding 507, negative. At armature 538 the relay 507 closes its own blocking circuit at armature 529 grounded.

   When the long distance operator answers and has informed himself of the request, the operator of the control desk withdraws by returning the key K to the normal position, which has the effect of attracting relay 105 and releasing the common equipment. as described above. The relay 105 by attracting, to the armature 139 puts the brush 152 to the ground to keep the relay 510 attracted, the armature 140 completes its blocking circuit and it opens the circuit of the relay 104; to armature 141 it completes the attraction circuit of relay 106 through

  <Desc / Clms Page number 47>

 the springs 157; at armature 145, it prepares the circuit of relay 102 at one point.

   The relay 106 by attracting, disconnects the translator coil and connects the caller directly to the trunk line through the brushes 151 to 154 inclusive.



   When the communication is terminated and the subscriber connected to the R.C.X. rings the end of the attraction circuit of relay 505 of the interurban junction closes followed by: the ringing current generated by the calling subscriber runs through the conversation wires marked in reinforced lines, it borrows the reinforcements 143 and 147 and their contacts at work, the brushes 151 and 154, the connector benches 581 and 582, the wires 161 and 164, the armatures 541 and 542 and their contacts at rest, the right windings of the translatrioe coil R05 and the rolais 505.



  Relay 505 to armature 533 closes the draw circuit of relay 501 and the latter to armatures 525 and 527 connects the generator ringing current to wires 590 and 591 through translator coil RC4 to the cord circuit of the operator to operate the end supervisory bodies in the well-known manner.



  The long distance operator is therefore notified that the conversation is over and if she wishes she can ring the caller again. On reception of the end signal, the long distance operator removes the jack J which opens the circuit of the relay 503 to the springs of the jack 521. The release of the relay 503 causes the release of the relay 502 after a certain time. At armature 529 and its contact at work, relay 502 opens the blocking circuit of relay 507 and at its rest contact momentarily completes the blocking circuit of relay 510, through armature 539, and during the time taken by relay 507 to release. The relay 507 in addition to its delay on attraction is slow on release.

   AT

  <Desc / Clms Page number 48>

 armature 530 relay 502 grounds wire 163 momentarily through armature 540 to close the local connector release relay 102 attraction circuit, as follows: positive to armature 530, armature 540, wire 163, bank contact 584, brush 153, armature 145, relay winding 102, negative. The relays 102 and 101 of the local connector attract in the manner previously described. In the trunk trunk the relay 507 releases after a certain time and at the armature opens 5-1: '-,' the circuit of the relay 102. As a result of the release of the relay 102 the relays 103 and 105 release.

   At armature 141, relay 105 opens the circuit of relay 106 which releases, at armature 139 it opens the circuit of relay 510 which also releases in the case where armature 539 is open. The local connector returns to the normal position as described previously and the trunk trunk and the local connector can therefore be used for other calls.



   The operator at the control desk is notified when all the local connectors are busy because they are all in service, or because the local subscribers have failed to ring the end of the call. The occupancy relay of all feeders 208 is normally drawn into the chain circuit of wire 69 which runs through all local connectors and is connected to earth through armatures 117, engagement springs 122 and of the springs 124 of the occupancy key in all the local connectors. When all of the local connectors are occupied all of the ground connections of wire 69 are removed, as a result the hold relay of all feeders 208 will drop.

   Relay 208 by releasing to armature 234 prepares at one point the circuit connecting the wire of the busy tone 223

  <Desc / Clms Page number 49>

 at the control junction, at armature 235, it disconnects the earth of the multiple bank contacts accessible to brush 255 to stop the brushes of the distributor; at armature 237 and on contact at work it opens the circuit of relay 203 at one point and at its contact at rest it prepares the circuit of relay 211 through its lower winding, at armature 233 it prepares at one point the re-circuit
 EMI49.1
 lais: 03% through its upper onrouloment, (ytiand 1 1 ol) c) - failure to retire after establishing the call which took the last available local connector, relay 306 by releasing closes the attraction circuit of relay 211 as following:

   positive to wire 262 grounded, armature 232 and contact at rest, wire 273, armature 330, wire 281, armature 237 and contact at rest, bottom winding
 EMI49.2
 du râlais 311, negative. Relay 211 an tlti! 'Cu1f h 1'01'- mature 248 connects the busy tone wire to wire 268, at armature 250 it closes its blocking circuit through its upper winding to earthed armatures 241 and 235; to armature 247 it connects armature 240 grounded to wire 269; at armature 251 it closes the circuit for attracting relay 207 to trovors its lower winding, at armature 285 it prepares the circuit of relay 209.

   At armature 231, relay 207 closes its blocking circuit through its lower winding than wire 264 to earth; at the armature 229 it opens the circuit of the control electro 401 at one point; at armature 232 and at rest contact it opens at one point the original attraction circuit of relay 211 and at work contact it completes the attraction circuit of relay 430 as described previously. As has already been said, relays 430 and 431 attract to warn the operator of the control desk. This responds by operating the key K and receives the occupancy tone indicating

  <Desc / Clms Page number 50>

 that all connectors are occupied.

   The busy tone sending circuit is as follows: tone wire 223, armature 234 =, armature 238, idle contact and armature 244, armature 248, wire 268, straight windings of the RC1 translator coil, wire 269, armature 297, armature 243 and contact at rest, wire 240 grounded. The busy tone is induced in the left windings of the translator coil RC1 and from there sent through the wires at junction 451 and 452 to the operator's station.



   To cut off the sending of the busy tone, the attendant transmits the number 1, as previously described, line relay 302 follows the received pulse and by releasing, pulls relay 311 and through l The armature 324, the wire 279, the armature 285, the armature 233 and its contact at rest closes the circuit of attraction of the relay 209 through its upper winding towards the negative.

   At armatures 238 and 240, relay 209 by attracting, disconnects the busy tone from the control junction, at armature 239 it completes its blocking circuit through its lower winding via wire 278 grounded , at armature 242 it prepares the circuit of electro 401 at one point, at armature 252 it opens at one point the original circuit of attraction of relay 430; on armature 289 it opens the blocking circuit of relay 431 to cause its release. The series relay 311 by attracting to the armature 350 and the on contact, closes the attraction circuit of the relay 312 which attracts and to the armature 351 prepares the circuit of the relay 313.



  At the end of the pulse, the relay 311 releases and on the armature 350 and its contact at work eliminates the short circuit of the relay 313 which draws in series with the relay

  <Desc / Clms Page number 51>

   312 through the grounded blocking wire 390. The relay 313 by attracting to the armature 354 prepares the circuit of the electro 401 of the supervisory switch.



  Relay 431 when releasing to armatures 434, 435 and 456 connects the brushes of the supervisory switch to the common equipment.



   For the purpose of checking local connections and to determine if local connectors are. eu service at the time considered the operator of the control desk emits the number 1 to bring the brushes to the bench contacts to which the first local connector ends. When line relay 302 releases as a result of sending this pulse, the following circuit is established: armatures 318 and 324, wire 279, armature 242, wire 280, armature 354, wire 276, winding of the control electro of the supervision switch 401, negative.

   As a result of the attraction and release of the electronic control 401, the brushes of the supervisory switch are brought to the first group of bank contacts, the brush 404 being connected to the wire 74, the brush 405 being connected to the wire 72 and the brush 406 being connected to the wire 73. As the relay 431 is not attracted at this moment, the control junction is bridged directly on the conversation wires of the first local connector via the armatures 435 and 436. L The operator is therefore able to determine whether there is a conversation in progress, if she hears nothing she announces herself online and if she obtains no answer she operates her two-position key.

   If the first local connector is in service, the attendant will hear the conversation in progress or receive a response when it announces itself. Since the first connector is in service, the attendant will emit the number 1 again to re-attract relay 302 and

  <Desc / Clms Page number 52>

 so that the control eleotro 401 brings the brushes of the supervision switch to the second local connector.



  The operator of the control desk continues to check all the other local connectors by releasing those which are not in use in a manner which will be described below. The rectifier cell 490 is bridged to the brushes 405 and 406 of the supervision switch to prevent the erected pulses from disturbing the connections already established and encountered by the brushes of the supervision switch.



   After the attendant has announced herself online to ensure that the connector on which the supervision switch brushes are engaged is not in service at the time considered, she operates the 2-position key to cause the attraction of the differential relay 501 as described previously. Following the operation of the differential relay 301, the relay 101 of the local connector connected to the brushes of the supervision switch attracts according to the circuit: positive at armature 316, wire 275, armature 434 and contact at rest, brush 404 engaged on the contact of bench where wire 74 of the local connector occupied but not in service ends, winding of relay 101, negative.

   The relay 101 of the local connector by attracting to the armature 156 partially short-circuits the winding of the relay-170 to cause the release of this one if it is attracted, to the armature 112 it opens the blocking circuit of the relays 103 and 105 to cause the release as well as that of the connector in the manner described above. All the local connectors controlled by the attendant and which are not in service at the time in question are released in the same way,
As soon as one of the local connectors becomes free, the positive is connected to the chain wire 69 by this one

  <Desc / Clms Page number 53>

 and the occupancy relay of all feeders 208 attracts.

   The relay 208 by attracting, to the armature 235 opens one of the multiple earth circuits of the relay 211 and connects the positive to the contact of the multiple bank accessible to the brush 255 to cause the distributor to search for a free connector. At armature 237, relay 208 prepares the circuit of relay 203 at one point and at armature 233 it prepares the circuit at one point
 EMI53.1
 of the shine 280. The prelui81'6 fols that the rolais 3U2 releases as a result of the sending of a pulse after one of the connectors has become free, the relay 280 draws in the following circuit: positive to the armature 318 and at contact at rest, armature 324, wire 279, armature 285, armature 233, winding of relay 280, negative. This pulse in addition to the fact that it operates the brushes of the supervisory switch therefore causes the operation of relay 280.

   At armature 241, relay 280 opens the blocking circuit of relay 211 which releases. Releasing relay 211, at armature 251, opens the original attraction circuit of rela.is 207 so that this relay will release when the attendant disconnects from the control junction. At armature 285, relay 211 opens the circuit of relay 280 to prevent it from being re-drawn. After having checked all the connectors, the operator withdraws and thereby opens the circuit of relay 302. Relay 302 and then relay 305 release. At armature 322, relay 305, when releasing, opens the circuit of relay 209 which releases and at armature 326 disconnects the earth of wire 264 to cause the release of relay 207.



   If the attendant withdraws without checking the local connectors, relay 208 is maintained in the operated position. The relay 211 remains attracted by the in-

  <Desc / Clms Page number 54>

 intermediate of the frame 235 and its contact at rest.



  The relay 207 also remains attracted by the intermediary of the armature 251. When the relay 209 releases following the release of the relay 305, the relay 430 re-attracts by the intermediary of the armatures 232 and 252 to once again warn the operator. via the circuit described above. From the above it can be seen that the operator is continually warned as long as all the connectors are occupied, so she must necessarily check the connectors and release at least one of those which are not in service.



   In the event that a fuse blows, or when the charger fails or when a connector does not return normally a group of relays (not shown) are provided to ground wire 236 in the well known manner applied. usually in systems
 EMI54.1
 a.1.t0: ¯: J.fi, aes. When wire 236 is earthed, the attraction circuit of relay 210 closes via armature 282. At armature 242, relay 210 prepares the circuit connecting the signaling current to wire 268 ; at armature 246 it completes the circuit of relay 211 in the case where relay 207 is not attracted; at armature 245 it opens the circuit of relay 203 at one point.



  If no call is in progress, relay 211 attracts following the circuit: positive to wire 262, armature 232 and contact at rest, wire 273, armature 330, wire 281, armature 246, lower winding of relay 211, negative. To armatures 248 and 247 the relay 211 connects the wire of the generator 75 by the intermediary of the capacitor M, the contact to the work and the armature 244 to the wire 268, then
 EMI54.2
 through the winding of the translatrioe coil;.; 1 to wire 269 and finally via armature 247 to armature 243 and its working contact to the return wire of generator 76. The ringing current is in-

  <Desc / Clms Page number 55>

 in the left winding of the RC1 translator coil to warn the operator, when she answers, that a fault has occurred in the R.C.X ..

   At armature 250, relay 211 closes its blocking circuit at armature 241 which is earthed; at armature 251 it completes the circuit for attracting relay 207 through its lower winding. The relay 207 by drawing to the armature 231 closes its blocking circuit; at armature 232 and its contact at work, it completes the attraction circuit of relay 430 to warn the operator of the control desk in the manner described above. When the attendant responds by lowering her key K, the signal transmitted by the generator as described above is heard by the attendant, which indicates that a fault has occurred in the RCX. The attendant withdraws by straightening her key K and thereby opening the circuit of relay 302.

   Relay 302 opens the circuit of relay 305, but before releasing relay 305 the attraction circuit of relay 280 closes as follows: positive to armature 318 and its contact at rest, armature 324, wire 279, armatures 285 and 284, relay winding 280, negative. Relay 280 at armature 283 blocks at alarm wire 236, at armature 282 it opens the circuit of relay 210 which releases, at armature 241 it opens the blocking circuit of relay 211.



  The relay 211 attracting to the armatures 248 and 247 disconnects the alarm tone of the translating coil RC1, to the armature 285 it opens the original circuit of attraction of the relay 280, finally to the armature 251 it opens the original circuit attraction of relay 207. Relay 210 by releasing at armatures 244 and 243 opens at another point the circuit connecting the alarm tone to the control junction; at armature 246 it opens the original circuit

  <Desc / Clms Page number 56>

 attraction of relay 211, at armature 245 it prepares the circuit of relay 203.

   After a certain time, relay 302 releases; relay 305 releases and at armature 323 opens the circuit of relay 311, at armature 326 it opens the circuit of relay 341 and the blocking circuit of relay 207, at armature 322 it opens the circuit of relay 306 The relays 431 and 207 release. When the positive is removed from the alarm wire 236, the blocking circuit of the relay 280 is opened, as a result this relay releases and at armature 282 connects the alarm wire to the relay 210.



   Divided calls.



   Referring to fig. 4 and! La we see that the. circuit of fig. 4 can be transformed to give the call divided by the incorporation of the relays of fig. 4a when these are connected to the corresponding terminals marked with a circle in fig. 4. In this case the dotted lines in fig. 4 are deleted and the corresponding terminals connected together. The relay group for the split call shown in fig. 4a gives the) possibility of ringing subscribers whose rings are connected between any of the line wires and the earth. Since the operation of the system is the same for all types of communications except as regards the mode of call, only a brief description of these operations will be given.

   To use the split call the operator after having sent the first of the two digits the called subscriber sends the digit 1 or the digit 2 to select the line wire on which the inrush current is to be transmitted to call the subscriber request.



     When relay 302 is released for the first time, when the first digit of the requested number is sent,

  <Desc / Clms Page number 57>

 this relay to the armature 317 closes the attraction circuit of the relay 701 as follows: positive to the armature 317, armature 332 and contact on, terminal 7, armature 707 and contact at rest, winding of relay 701, negative.



  On armature 706, relay 701 prepares the pull circuit of relay 702 in series with relay 701, but relay 702 is short-circuited by the positive to the blocking wire 390 and through the intermediary of the armature 359, from terminal 8 of armature 706 and from positive to armature 317. At the end of the first pulse when the
 EMI57.1
 1'u10.io N03 ruutbiru lu posibif Qsb ddoollituot6 du lu bUJ: JW 7 which eliminates the short circuit of relay 702 which draws in series with relay 701 through the grounded blocking wire 390. A the armature 707 the relay 702 opens the original attraction circuit of the relay 701 and on contact with the work of the armature 707 it prepares the circuit of the relay 703.

   Under the action of the second pulse of the first digit, relay 703 draws into the following circuit: positive to armature 317, armature 332, terminal 7, armature 707, armature 710, winding of relay 703, negative. Similarly, relay 703 to armature 709 prepares the circuit for relay 704 but this is short-circuited by wire 390 grounded until relay 302 re-attracts and removes the short circuit. from relay 704 to armature 317.



  The subsequent pulses are inoperative with regard to relays 701 to 704 and they therefore remain attracted - through the grounded blocking wire 390: Under the action of the pulses of the second digit of the number called the relay series 311 attracts and causes the attraction of relay 314 which at armature 359 opens the blocking circuit of relays 701 to 704 which release. Relays 701 to 704 attract under the action of

  <Desc / Clms Page number 58>

 pulses of the first digit sent by the operator 'day allow the latter to establish a communication
 EMI58.1
 "L.: '1'" duax uuuüaés related to the denial l1Óll6 P'-1.L'tugée.



  In a call of this kind the first digit emitted determines the line wire on which the ringing current will be transmitted to the called subscriber. It will be remembered that at the end of the second digit the series relay 311 releases and causes the attraction of the relay 315 which, at the armature 361, prepares the blocking circuit of the relays 701 to 704 inclusive. Except for calls between two subscribers connected to the same shared line, the next digit, or third digit, determines on which wire of the called line the inrush current will be transmitted. In the event that the third digit emitted is the number 1, the relays 701 and 702 re-attract and lock to the wire 390 through the armature 361.

   Relays 701 and 702 are the only ones that operate for digit 1 and the bell relay circuit 705 does not close in this case, it follows that when the call key is operated the relay 308 attracts as described. previously but this time the circuit passes through terminal 6, the araature 711 and its contact at rest, terminal 5 and the winding of the bell relay 308. The wire of the generator 75 is connected to the negative brush 151 to ring the subscribers which have their ringtones connected between the negative wire and the ground.

   In the case where the number 2 is emitted as the third number, the relays 701 and 702 attract as for the first pulse and the relays 703 and 704 attract under the action of the second pulse as described previously. At the armature 708 the relay 704 by attracting prepares the circuit of the electro rotation of the local connector to allow the operator of the control desk to advance the brushes of the connector.

  <Desc / Clms Page number 59>

 one step at a time to select a free trunk trunk. At armature 711, relay 704 prepares the circuit of relay 705, at armature 711 and its contact at rest it opens the circuit connecting terminal 6 to terminal 5.

   When the operator operates her call key according to the code of the subscriber called the relay 705 attracts, each time the differential relay 301 operates, as follows: positive at armature 316, wire 275, armature 434 and contact on work, wire 274, armature 321 and contact on, terminal 6, armature 711 and contact on, relay winding 705, negative. On armature 712 and when the contact is at rest, relay 705 disconnects terminal 2 from terminal 1, when contact is open it connects terminal 2 to terminal 4. At armature 713 and when contact is idle, relay 705 disconnects terminal 3 of terminal 4 and the NO contact connects terminal 3 to terminal 1. The operation of armatures 712 and 713 therefore reverses the connections of the inrush circuit.

   At armature 714, relay 705 closes the attraction circuit of bell relay 318 as follows: positive at armature 714, terminal 5, winding of bell relay 308, negative. Whenever relay 705 pulls relay 308 also pulls and closes the following circuit: generator wire '75, NC contact and armature 338, terminal 1, NC contact and armature 713, terminal 3, wire 188, armature 136, broom 154, called party line positive wire and bell connected to this line wire, earth.



   When the operator of the order desk establishes a communication towards an interurban junction she always emits the digit '2 to prepare the circuit of relay 705 and to cause the attraction of relay 704 which to its armature 708 connects terminal 10 to terminal 9 to allow the operator of the order desk to ac-

  <Desc / Clms Page number 60>

 Operate the local connector's rotation electromagnet to advance the brushes of the latter one step at a time to find a free trunk line in a group.



   Tone for prepaid telephone.



   It will now be assumed that the calling subscriber uses a prepaid set. Referring to the LC line circuit of fig. 1 it can be seen that wires 86 and 42 alone are connected to the line circuit in the
 EMI60.1
 case of a prepaid item. In this case, it will be assumed that the subscriber line shown in the upper left corner is that of a prepaid station and
 EMI60.2
 that the wires -: h2 and 86 are connected neck, -., e it is represented .¯f: '¯t ..- L2au3 on é.1 and an a9'el au: xoyen of a pre- ): Üe. ::::;

  l1t eii activating the generator, the other live relay. Relay 11 closes its blocking circuit through its lower winding and also closes via wire 42 the attraction circuit of relay 43 (fig. 4) in the group of tone relays for
 EMI60.3
 ¯> ostz 1. prepaid. At armature 7, relay 3 sets up the blocking circuit at 1 ar: ature zip3, at ar:.; Ature '16 it tr4? Are at a point the connection circuit of te- -iali3 for prepaid station: .. ent at the cont junction! <3l'3 via wires 85 'and 270. Starter relay 201 also attracts in series with line relay 11 to cause the search for the calling line by a free seeker and to attract the relay cut-off 12 as described above.

   The cut-off relay 12 to the armature 18 opens the blocking circuit of the relay 11 as well as the original circuit of attraction of the relay 43. The relays 11 and 43 are kept attracted by the intermediary of the positive of the armature 48. The same positive keeping cutoff relay 12 attracted occurs.

  <Desc / Clms Page number 61>

 lanyard through wire 86 to attract relay 82. At armature 83, relay 82 closes in a joint the circuit connecting the tone for prepaid station to wire 270 of the control junction.



   When the attendant answers the call, the relays 302, 305 and 306 attract as described previously. At the armature 322, the relay 305 closes the attraction circuit of the relay 81 which causes its weighted armature to vibrate. Relay 45 is slow to pull, so it does not pull completely while armature 80 is vibrating. When arming 389, relay 306 closes the circuit for attracting differential relay 84 through its lower winding. Relay 84 attracts and armature 49 closes the circuit of its upper winding so that it releases and armature 49 opens. When armature 49 opens differential relay 84 attracts again through its lower winding and closes again. arma bure 19 to bring about its own release.

   Differential relay 84 operates like a buzzer to generate a tone which is connected to the control junction through capacitor 50, armatures 83 and 46, and wires 85 and 270. Some time after the relay 81 has attracted the vibrating armature is kept attracted which causes the attraction of the slow relay at attraction 45. Because the weighted armature 80 continues to vibrate for a determined time, the slow relay at attraction 45 n do not attract until a certain time has elapsed. The relay 45 by attracting. To the armature 48 opens the blocking circuit of the relays 43 and 11.

   At armature 46, relay 43 disconnects the dial tone from the control junction and relay 11 by completely releasing at armature 15 the conversation circuit between the operator and the subscriber using the set.

  <Desc / Clms Page number 62>

 prepaid.

   It will be noted that the tone for a prepaid station is generated each time the common equipment is put into service by the operator of the remote office if the relay 82 were removed there would be the possibility for the operator to hear the dial tone. prepaid set when answering a regular call if a subscriber using a prepaid set made a call immediately after a regular subscriber.

   for example, supposing that a subscriber, with local battery, ordinary made a call and alerted the operator and that before the answer of this one a subscriber using a prepaid set also initiates a call, under these conditions relay 43 is attracted but as the dispenser is on and has not yet been released to allow a pager to search for the calling line relay 82 is not attracted and the dial tone for prepaid station n 'is not connected to the trunk when the attendant answers the call from the ordinary set.



   In the case considered if the relay 82 had been omitted when the operator had answered the call of the ordinary subscriber she would have heard the dial tone.
 EMI62.1
 :. J1. ' .Je 10 ..:. In what would have given it a 1 ± 1 (11 Where t1 "is false. The presence of relay 82 means that the dial tone for a prepaid station is connected to the junction only when a seeker is connected to the post line and when the common equipment has been entered for this abbel.


    

Claims (1)

CLAIMS. 1. A telephone system comprising an unsupervised office equipped with automatic switches for the establishment of local and long distance communications. EMI63.1 n'llf1 7 oontrnig rl'll11ü j5rrzt; r'lnn non ll '(J11VlJl1l, riii 1111 f'n- right away from this office in which the sending of a call to the monitored office alerts the operator and causes the selection of a free switch, the operation of the selected switch being controlled by the operator by means of two wires connected in series which connect the operator position and the unattended desk while sending of inrush current to the requested subscriber is controlled by the operator using the same wires connected in parallel. 2. A telephone system comprising an unattended office equipped with automatic switches for the establishment of local and long-distance communications under the control of an operator located in a place far from this office in which the connections to the unattended office are carried out under the control of the operator via a two-way junction, components common to all the switches of the local office being provided to establish a conversation circuit between the operator and the operator. calling subscriber or called subscriber by means of this junction, these units being controlled either automatically for certain stages of the selection or under the control of the operator. 3. A telephone system comprising an unattended office equipped with automatic switches for establishing local and long-distance communications under the control of an operator located in a place far from this office in which a signal is <Desc / Clms Page number 64> automatically transmitted to the attendant when all the switches are engaged, the latter then checks the switches and releases those of them that are not in service, this same signal being retransmitted if the attendant answers and cuts off connection without knowing the cause of its sending. 4. A telephone system comprising an unsupervised office / automatic switches for the establishment EMI64.1 cai:.; local anications under the control of an OP3- ratrix in which individual devices to the subscriber lines are provided to provide the power supply for the conversation, the operation of these devices when the The subscriber hangs up at the end of the call used to send a short pulse which causes the automatic release of the connection. 5. A telephone system as claimed in claim 1 in which the wires are normally connected: - in series, this serial connection being opened at the notice of the sending of a call to cause the inter- EMI64.2 mi an iirnal towards the OPÓ1'Q,! 'lce of the Óloi01Ó office. 6. A telephone system as claimed in claim 1 in which the setting of the switch in the unattended office is effected by means of a relay common to all the switches and controlled by the attendant by the operator. 'intermediary of the two wires connected in series. 7. A telephone system as claimed in claim 1, 2 or 3 in which a differential relay at the unattended office is connected in series with the two wires of the junction and is controlled by the operator to establish the talk circuit. between the operator and the calling subscriber and to cause the sending of the inrush current on the called line or to cause, <Desc / Clms Page number 65> while checking which switches are engaged, release those which are not in service. 8. A telephone system as claimed in claim 5 in which the serial link is opened, due to the pull of a relay, when a free switch is found. 9. A telephone system as claimed in claim 1 in which an unattended office differential relay is connected to each of said wires and operates when in the operator position one of these wires is connected to earth. 10. A telephone system as claimed in claim 1 in which when a call is made from a prepaid station a special dial tone is generated at the unsupervised office and transmitted through the two wires to the telephone. operator. 11. A telephone system as claimed in claim 2 in which the first operation of the key by the operatriae disconnects the called subscriber from the trunk and connects the calling subscriber to it while subsequent operations of this key transmit the inrush current on the called line. 12. A telephone system as claimed in claim 2 in which a conversation circuit between the operator and the called subscriber closes automatically when a selector has been placed on the called line. 13. A telephone system as claimed in claim 12 in which the operation of a relay in the unattended office upon completion of the sending of the pulses completes the establishment of the conversation circuit. 14. A telephone system as claimed in claim <Desc / Clms Page number 66> cation 13 in which the operation of a key by the operator releases the relay to establish a conversation circuit between the operator and the calling subscriber. 15. A telephone system as claimed in common claim 2 in which there is provided a coil translating to all the switches of the unattended office which establishes a temporary conversation circuit between the calling and called subscribers, the two wires of the telephone. junction being connected to the same side of the coil. 16. A telephone system as claimed in claim 15 in which a conversation circuit between the calling and called subscribers is established when the attendant withdraws from the trunk to the unattended office. 17. A telephone system as claimed in claim 3 in which a supervisory switch has been provided at the unattended office having access to the conversation wires of the selectors, the supervisory switch being successively connected to the conversation wires. switches whatever their state, free or busy, to allow the attendant to check this state. 18. A telephone system as claimed in claim 17 in which the supervisory switch advances step by step under the action of the impulses transmitted by the operator through the two-wire trunk. 19. A telephone system as claimed in claim 17 or 18 in which a rectifier cell is bridged to the brushes of the supervisory switch to avoid disturbances which occur on the conversation wires of the switches during supervision. 20. A telephone system as claimed in claim <Desc / Clms Page number 67> cation 4 in which the operation of the individual units when a subscriber goes off hook to make a call causes the transmission of a signal to the operator to let him know that a call is pending. 21. A telephone system as claimed in claim 4 or 20 in which the individual parts include a relay which, when the line is called, is disconnected from it while the call current is being sent. A telephone system as claimed in claim 20 or 21 in which an individual relay on each line operates while the inrush current is being sent to disconnect that first relay from the line and to pass the current on to it. 'call on one of the line wires connected to the earth. 23. A telephone system as claimed in claim 21 or 22 and having shared lines constituting two groups of subscribers which have their ringers connected in a different manner in which the line wire over which ringing current is transmitted is chosen by sending an additional digit by the operator to attract one or two relays depending on the value of the digit sent. 24. A telephone system as claimed in claim 1 or 2 in which the release of local connections is made by either of the subscribers while in the case of long distance communications control is removed from the subscribers. and exercised by the operator who established the communication. EMI67.1 25 * A telephone system in pr1no1HiI oommo due rit wh ro- presented in the appended plans. @