Patent GB-279058-A (GB)
Title: Improvements in or relating to telephone systems
IPC: H04Q3/42
Filed: 1927-09-27
Abstract: 279,058. Associated Telephone & Telegraph Co., (Assignees of Stehlik, R. F.). Oct. 18, 1926, [Convention date]. Automatic exchange systems.-In a registercontroller of the code-translating type, the exchange designation (comprising two digits) is registered on a two-directional switch OR and the remaining digits are registered under control of a relay-chain 211-215 on sets of storage relays THU, H, T, the same set being used for the thousands and units digits. The impulses sent out are counted by a relay-chain 321-325. and the wipers of the switch OR and the storage relaysets are made effective in turn by means of a control relay-chain 201-206. The relay-chains comprise two-step relays, and are arranged so that for certain digits or control positions two or more relays may be operated. The scheme of operation of these relays is shown in Figs. 6, 8, 9, while Fig. 7 show the scheme of operation of the storage relays. Means are provided at the distributing frame IDF by which, if the routing-number does not comprise the full number of digits, or if the exchange designation is to be suppressed, certain of the relays 201-206 are energized in quick succession to " skip " the corresponding control positions, Registration of wanted number. The switch DS is started up by the energization of release relay 105 to seize an idle registercontroller. Release relay 302 energizes over wire 132 and lights lamp 338, and dial tone is connected from transformer 246 to impulse wire 131 and thence to line through a condenser. Dialled impulses are repeated by line relay 104 over wire 131 to repeating relay 305, release relay 105 being rendered slow-to-release bv shortcircuiting. The first impulse train is repeated over wire 236 to vertical magnet 408 of the register-switch OR. Relays 306, 307, both of which are slow-to-release, energize in turn at the first impulse, and fall back in turn at the end of the train, sending an impulse over wire 239 to energize two-step relay 207, which locks to wire 240 and brings in rotary magnet 407 in place of vertical magnet 408. After the second train of impulses (which completes the exchange designation), two-step relay 208 energizes in a similar manner, transfers the impulse circuit 236 over wire 246 to the relay-chain 211-215, transfers wire 239 to set-up wire 247, and connects up relay 504, which connects set-up wires 241-244 to the thousands storage relays A1-D1. The thousands impulses are registered in the relay-chain 211-215, locking wire 245 being grounded by relay 307 during the train, and the corresponding storage relays A1-D1 are energized at the end of the train over the contacts thereof by the impulse received over wire 239. The operated storage relays lock over wires 214, 240 in series with relay 501, which substitutes relay 505 for relay 504 to bring in the next set of storage relays. When the tens digit has been registered, relay 503 disconnects relay 506 and prepares a fresh circuit for relay 504, but the units digit cannot be transferred from the relaychain 211-215 to the storage relays A1-D1 until the thousands digit has been retransmitted. When relay 306 falls back after the. units impulse train, the impulse over wire 239 is sent over wires 216, 312 to energize receiving-stop relay 304, which locks, opens the impulse circuit 236 and closes a holding circuit for relay 307. Transmission of routing-number. This is started as soon as the exchange digits have been recorded by the grounding of wire 219 by relay 208, closing a circuit over wire 237 for interrupter 311 and sending relay 310, which controls the impulse circuit 133, 134 of the selector S at contact 354. Relay 310 also sends impulses to the relay-chain 321-325. The first impulse through relay 310 serves only to energize relay 321, which operates pick-up relay 308 to remove a shunt across impulse contact 354, and start the sending operation. Assuming the first routing digit to be O, after ten impulses have been sent, stop relay 309 energizes over wire 356, contacts of relays 321-325, stop wire O, distributing frame 1DF and wiper 401 of the registerswitch OR, locks, disconnects sending relay 310 and releases pick-up relay 308 and relays 321-- 325. Relay 309 relapses slowly and again connects up sending relay 310 to transmit the next digit. Two-step relay 201, which energizes partially in parallel with relay 309 over wire 238, now energizes fully and transfers the control to the second wiper 402 of the register-switch OR. As shown, the terminals on which wipers 401-106 are set are connected at the distributing frame 1DF to transmit three routing digits, the last three terminals being connected to skip conductor 209, over which relays 204, 205, 206 are energized in quick succession in parallel with stop relay 309, which prevents the operation of sending relay 310. The complete exchange designation may be suppressed by connecting all the terminals to skip conductor 209. Retransmission of numerical digits. Relay 206 on operation connects up thousands stop wire 231 in place of wiper 406, and closes a fresh circuit for sending relay 310 over wire 251, provided the thousands digit has been registered, that is, relay 501 is energized. The thousands impulses are sent out by relay 310 until stop relay 309 energizes over contacts of relays 321-325 and relays A1-D1 and wire 231. An impulse is sent over wire 238 to energize relay 201 (for the second time) to render the next set of storage relays effective by connecting up wires 232, 252 in place of wires 231, 251. When relay 202 energizes after the hundrels impulses have been transmitted, wire 210 is disconnected from locking wire 240, causing relay 501 to relapse. Relay 504 energizes and transfers the units digit from the relay-chains 211-215 to the storage relays A1-D1. After the tens impulses have been sent out, relays 203, 206 are both operated, and relay 307 (previously held over 312, 216) releases, restoring the relay-chain 211-215. At the same time, relay 202 is unlocked, and the locking circuit for relays A1-D1 over relay 501 is re-closed. The latter relay disconnects relay 504 and completes the circuit of sending relay 310 for transmission of the units impulses. Switching through and release of the registercontroller. The final impulse over wire 238 at the end of the units impulses energizes relay 204, which connects up switching relay 303, which locks and grounds impulse wire 131 to short-circuit release relay 105 and energize switching relay 106. The switch DS restores when relay 105 falls back, and release relay 302 is disconnected. Guard relay 301, being no longer short-circuited, energizes over wire 227, locks and completes the release circuit for the registerswitch OR. Relay 302 disconnects all the relays which are locked over wire 240 and closes a flashing circuit for lamp 338. Relay 301 falls back when the switch OR reaches normal. If the switch does not restore, lamp 338 continues to flash, and a common supervisory relay in series with relay 301 causes an alarm to be sounded. Specification 294,885 is referred to.