Patent GB-272310-A (GB)
Title: Improvements in or relating to automatic or semi-automatic telephone systems
IPC: H04Q3/42
Filed: 1926-03-20
Abstract: 272,310. Coventry Automatic Telephones, Ltd., and Moss, B. F. March 20, 1926. Automatic exchange systems. - A registercontroller of the code-translating type contains no step-by-step switches, the registration of the dialled digits, the distribution of the digits to the separate registers, and the control of the sequence of operations during the sending out of the translated and untranslated digits, all being effected by relay-chains. In the apparatus shown in Figs. 3-6 ('which should be arranged with Figs. 3, 4, 5 in order from left to right and with Fig. 6 above Fig. 5), the first three (code) digits are repeated by relay 11 to register-chains R1 - - R3 and result in the operation of a relay 13 individual to theparticular exchange required. Relay-chains R1 - - R3 are then released and used again for numerical digits in conjunction with a fourth chain R4, the routing of all the digits to the proper registers being controlled by a relay-chain RS, Fig. 3. The sequence of operations during the sending out of the routing-digits (up to a maximum of six) and of the four numerical digits is controlled by a further relay-chain TS, Fig. 6.. consisting of six relays 190 - - 195, the first five. of which are each used twice in connection with two different digits. The impulse-sending means comprises springs 272, Fig. 6, which are connected up for varying lengths of time to send from one to ten impulses under control of cams 231 - - 240 of a common machine M, Fig. 5. Registration of wanted number. When the register-controller is seized, relay 11 operates and completes circuits for relays 29, 36. Relay 29 closes a cricuit 37, 40, 41 for relay 42. The first impulse of the first digit is repeated by relay 11 over the circuit 51, 53, 54, 131, 56, 59 to relay 105 of the first register-chain R1. The release of relay 11 also operates relay 71 which closes a circuit 37, 73, for relay 72. Relay 105 locks to lead 69 and, at the end of the impulse, as relay 76 is energized over the circuit 82, 81, 80, 77, 133, 54, 53, 51. The second impulse, therefore. passes over the front contact 55 of relay 76 and leads 132, 86 to relay 106 which unlocks relay 105. At the end of this impulse, relay 76 releases and the third impulse passes over back contact 55 and leads 131, 59 to relay 107. In a similar manner, the fourth and fifth impulses operate relays 108, 109 and at the sixth impulse, relay 105 is again operated and in addition a circuit is closed for relay 110 which locks directly to lead 69. Assuming that the digit consists of nine impulses, relays 108, 110 will be operated at the end of the digit and battery over contacts 63, 95 and lead 96 will be connected to the right-hand windings of all relays such as relay 13 to exchange-designations having a first digit. equivalent 9. The relapse of relay 71 at the end of the digit completes a circuit over contacts 37, 40, 112 for relay 43 which releases relay 42 and connects leads 131 - - 134 to the second registerchain R2. The second digit is then recorded in a similar manner and as a result thereof, earth is connected over the circuit 50, 401, 402, 149, to the opposite side of the right-hand windings of relays 13 corresponding to exchangedesignations having a particular second digit. When relay 71 operates at the beginning of the second digit, relay 72 is released and when relay 71 releases at the end of the digit, relay 44 operates so that the third digit is recorded on the register-chain R3. As a result of this, earth is connected over leads 152, 350 to the left-hand windings of a group of relays such as relay 13 but since these relays only operate when both windings receive current, only that one corresponding to the three exchange digits dialled will operate. This will lock up over its left-hand winding in series with relays 154. The first numerical digit is recorded in a similar manner upon the register-chain R4 and during this digit the operation of relays 45, 71 closes a circuit for relay 148 which pulls up slowly. During the interval between the response of relays 71, 148, earth is removed from the locking lead 69 and the first three chains R1 - - R3 are released. At the end of this digit relay 42 again pulls up and the remaining three numerical digits are recorded on registers R1 - - R3. During this operation relays 42 - - 44 remain locked up over contacts of relay 148 so that during the final digit the response of relay 71 completes a circuit 37, 39, 169 for two-step relay 52 which at first pulls up partially and, at the end of the digit, operates completely over both windings. Transmission of translated routing-member. The operation of relay 154 in series with relay 13 connects relay 206 to brush 208 of the impulsemachine M. The first operation of relay 206 over cam 209 completes a circuit for the lefthand winding of two-step relay 210 and on the release of relay 206 relay 210 operates completely. The next operation of relay 206 connects relay 251 over the circuit 252, 253, 260. 261, 262. 254, and thence over a jumper at the distributing frame CF to impulse lead 9 and brush 219. Relay 251 operates over cam 229 and completes a locking circuit in which relay 264 operates as soon as brush 219 leaves this cam. Relay 267 is then operated over cam 239 to remove a short-circuit from impulse spring 272, the dimensions of cam 239 being such that relay 267 remains energized for a sufficient time to permit nine impulses to be transmitted over the outgoing leads 269, 270. Relay 264 also closes a circuit for relay 189 which in turn operates relay 276 over contacts 277, 275, 278, 157. At the end of the digit, the release of relay 206 energizes relay 287 which completes a circuit for relay 191. At the next engagement of brush 208 with cam 209, relays 206, 251 operate again and three more routing digits 6, 1, 4 are sent out in a similar manner after which relay 194 is operated. Since, in the present example, four routing digits only are employed, no circuit is completed over lead 258 for relay 251. Relay 279, which was previously short-circuited at contacts 281, now operates and completes a circuit for relay 191, the latter in turn operating relay 195. Retransmission of numerical digits. Relays 191, 195 energize relay 304 which connects up relay 282. Relay 251 now energizes over contacts 260, 261, 329, 316, leads 172, and one of the leads 176 - - 185 according to the setting of the relay chain R4 and impulses corresponding to the value of the first numerical digit are sent out by springs 272. (The inclusion of contacts 316 and similar contacts 317, 318, 171 in the circuits for relay 251 ensures that the retransmission on any digit is not commenced until that digit has been completely registered). The operation of relay 267 during the digit energizes. relay 282 which on the release of relay 206 completes a circuit for relay 287. Relay 192 therefore operates and the second and succeeding numerical digits are sent out in a similar manner. During the final digit, relays 195, 194, 251 partially operate two-step relay 32 which at the end of the digit operates completely, releasing relays 29, 36 and thus restoring the registercontroller to normal. Specifications 228,660, 235,027, 235,824, and 287,983 are referred to.