Patent GB-144264-A (GB)
IPC: H04Q3/00
Filed: 1920-05-11
Abstract: 144,264. Western Electric Co., (Assignees of Polinkowsky, L.). June 5, 1919, [Convention date]. Automatic and semi-automatic exchange systems.-A call is set up partly by step-by-step selectors operator directly by incoming impulses and partly by power-driven selectors operating under the control of registers set by further impulses from the same source,. In the system described, a call is set up bv a group selector at an exchange, Fig. 1, employing step-by-step switches, and by other group selectors and a final selector at a second exchange, Fig. 2, employing power-driven switches, the connexion including a two-wire interchange trunk 200. Two register sets are available at the second exchange for handling calls from the first exchange, one of these sets being shown in Fig. 3. The equipment at the second exchange is assumed to be of the type in which the registers must be set to the complements of the digits of the wanted number, the impulse-senders of the subscribers on this exchange being arranged to send the complementary numbers. Arrangements must therefore be provided at the second exchange for inverting the digits received from the first exchange. This is effected by recording each digit, as it arrives, on a register 150, Fig. 3, which then continues its rotation until it regains its normal position, and in so doing records the complement of the digit on the thousands, hundreds, &c. registers 110, 120, &c. The equipment of the second exchange may be on a non-decimal basis, the registers being arranged to effect the necessary translation. Step-by-step group selector and repeater, Fig. 1. The first set of impulses (interruptions of the calling line circuit) are repeated by relay 100 to the slow-release relay 104 and primary stepping- magnet PM, and at the termination of the impulses relay 104 relapses and releases magnet ESC, which trips the side-switch to its 2nd position, in which the hunting movement of the selector is effected by the secondary stepping- magnet SM. The magnet ESC is energized, during this movement, at first over the normal contact SON and then over the test-brush 125, but relapses when an idle trunk is found and trips the side-switch to its 3rd position. Relay 108 is now connected to line in place of relay 100, energizing relay 109, which supplies a holding-circuit for relay 103, and bridging the outgoing trunk 200 through relay 117 and inductance 128 so as to energize relay 201, Fig. 2. Subsequent impulses are repeated by relay 108 to relay 201. relay 117 and inductance 128 being short-circuited by a slow-release relay 116 as long as impulses are passing. Connexion of the inter-exchange trunk to an idle register-controller, Fig. 3. Relay 201, Fig. 2, energizes relay 203, and if the register-controller shown in Fig. 3 is idle relay 203 completes the circuit 217 of relay 205, which locks itself up in series with relays 204, 206, and 339, Fig. 3, whereby the register-controller is appropriated and rendered non-selectable to other calls by the opening of circuit 217. (If the register-controller shown in Fig. 3 is already engaged, connexion is made to the second register-controller, if idle, by a relay 208 corresponding to relay 205. If both register-controllers are idle, relays 205, 208 are energized simultaneously, but the energization of relay 208 is only momentary, as its locking- circuit is opened by relay 205.) Registration of the called digits. The registering and controlling operations of the registercontroller are governed, respectively, by sequence switches 320, 350. A slow-response relay 334, energized in a circuit controlled by relays 201, 204, drives switch 320 to its 2nd position, closing a circuit 347, 352 for driving the switch 350 also to its 2nd position, and circuits are then closed for advancing the switches 220 and 350 to their 3rd positions. When the next series of impulses arrives, they are repeated by relav 201 to a differential relay 329, which controls the powerdriven register 150 in known manner, advancing it a step at each impulse. At the first impulse, relay 334 relapses, driving switch 320 to its 3rd position. At the termination of the series of impulses, the slow-response relay 334 is again energized and drives the switch 320 to its 4th position, completing a circuit 336, 152 for driving register 150 forward to its zero position. During this part of its movement, register 150 intermittingly closes a circuit 153, 328 to record the complement of the digit on the thousands register 110, and when the register 150 regains its zero position contact 154 closes a circuit to drive switch 320 to its 5th position. The register 150 is similarly operated by each series of impulses as they arrive, and in returning to its zero position sets the hundreds, tens and units registers 120, 130, 140 in turn to positions corresponding to the complements of the digits. At the end of these operations switch 320 stands in its 14th position. Control of the selectors by the registers. When switch 320 moved to its 5th position, after the setting of the thousands register 110, a circuit 347, 352 was closed to drive switch 350 to its 4th position, energizing relay 355 in series with relay 222, which drives switch 220 to its 4th position. The power-magnet 248 is now energized to rotate the brush-choosing spindle and at each step an interruptor 255 grounds a point in the circuit between relays 222, 355, intermittingly de-energizing the latter, which controls a differential relay 359 to advance register 110 in known manner over circuit 361, 112 towards its zero position. At the next de-energization of relay 355 after register 110 has regained its zero position, a circuit 361, 114, 354 is closed to drive switch 350 to its 5th position, and a relay 362 in a branch of the same circuit opens the circuit of relay 222, which relapses and drives switch 220 to its 5th position, de-energizing power magent 248. Relay 222 is now energized in a circuit through the back contact of relay 216, and the power magnet 261 is energized to rotate the brush carriage. When an idle trunk is found, relays 234, 232 are energized to de-energize the power magnet 261 and to move switch 220 to its 6th position, extending the circuit of the stepping-relay 355 to the next selector 282 over contacts 278, 279. If the setting of the hundreds register 120 has been completed, switch 320 has reached its 8th position and has closed circuit 340, 356 to move switch 350 to its 7th position, so that the circuit of relay 355 is completed at contact 357. The setting of the selector 282 proceeds under control of this circuit, the intermittent de-energization of relay 355 controlling relay 359 to restore the hundreds register 120 to its zero position over circuit 361, 122, whereupon a circuit 361. 124. 114, 354 is closed to energize relay 362 and to drive switch 350 to its 8th position, opening the fundamental circuit at the back contact of relay 362 and at contact 357. If switch 320 has reached its 11th position, circuit 341, 342 is closed to drive switch 350 to its 9th position, again completing the fundamental circuit at contact 357. The setting of the final selector 285 proceeds in a similar manner under control of the tens and units registers 130, 140, and at the next de-energization of the stepping- relay 355 after the selection of the wanted line has been completed a circuit 360, 144, 364 is closed to drive switch 350 to its normal 1st position. Contact 369 then drives switch 320 also to its normal position, and contact 358 unlocks relays 339, 204, 206, 205 so as to disconnect the register-controller and leave it available for other calls. The relapse of relay 205 drives switch 220 to its 7th position, connecting a repeater 229 to the final selector. If the wanted line tests idle, a circuit is momentarily closed to energize relay 242, which drives switch 220 to its 10th position, and on the called subscriber replying relay 242 is again energized and drives switch 220 to its 13th position, in which conversation takes place. In this position relay 202 is energized to reverse the current in the calling line, for metering or other purposes. Translating-arrangements. Translation may be effected by the use of relays 274, 376, Fig. 3, which modify the operations of the registers. If the digit recorded on the thousands register 110 is an odd number, relay 376 is energized as switch 350 runs from its 3rd to its 4th position, and locks itself up, closing a circuit to contact 113 so that the register will stop when it reaches its 9th position. instead of returning to normal. At the next deenergization of the stepping-relay 355 after the hundreds register 120 reaches its zero position (switch 350 being in its 7th position and relay 376 therefore unlocked) a circuit 361, 124, 113 is closed for moving the thousands register to normal, and it is not until the succeeding deenergization of relav 355 that the fundamental circuit is opened and switch 350 advanced to its 8th position. The result is that if the thousands digit is odd the selector controlled by the thousands register takes one step less and the selector controlled by the hundreds register takes one step more than would be the case in a purely decimal system. If the hundreds digit is odd, relay 374 is energized as switch 350 runs through its 6th position and locks itself up. This has the effect of causing the units register 140 to run through an additional cycle, after its first return to zero position, adding ten steps to the units movement of the final selector. The next deenergization of the stepping-relay 355 after the register 140 first returns to zero (switch 350 being in its 11th position) closes a circuit 360, 144, front contact of relay 374 to drive the register again to its 1st position, momentarily opening contact 146 so as to unlock relay 374. Further de-energizations of relay 355 advance the register through the circuit 360, 1