Patent GB-656562-A (GB)
Title: Improvements in or relating to telephone systems
IPC: H04Q3/00
Filed: 1948-02-20
Abstract: 656,562. Automatic exchange systems. WESTERN ELECTRIC CO., Inc. Feb. 20, 1948, No. 5090. Convention date, May 15, 1940. [Class 40 (iv)] In a system of the kind in which calls are set up between subscribers in different exchanges under the control of an operator at a central exchange not in the line of connection, a register sender controlled by the operator is split between the central exchange and a terminal switch. ing exchange, the two parts of the sender being described for convenience as the control section and the terminal section. The two sections are connected by four conductors and each section comprises a register. The system includes a marker and a terminal section of a sender arranged as a unit common to two exchanges housed in the same building, as described in Specification 656,563. The Figures should be arranged as shown in Fig. 12. When a call originates at a manual exchange X, Fig. 1, an A operator selects a junctor 101 leading to the wanted exchange M or N, M and N both being in the same building. A sender connector 110 hunts for the terminal section, Figs. 2 to 5, 7, 8, of an idle sender and a talking circuit is established to the control sender, Figs. 6 and 9 to 11. A position-finder 900 then hunts for and seizes an idle B operator's position, Fig. 6. A tone signal is transmitted from the B position to the A position and both lamp signals and tone signals are given at the B position. When the A operator repeats the wanted number, the B operator sets it up on a key-set 640 controlling a register, Fig. 11. When the registration is complete, the B operator's position is released and the number is transferred by revertive impulses to a cross-bar register, Figs. 4, 7, in the terminal section of the sender. The number is then transferred to a marker, Fig. 8, not shown, which sets up a connection between the junction and the wanted line. The sender and the marker are released. If the selected junction gives access to both of the two exchanges M, N the B operator receives a tone indicating that an exchange indication will be necessary. On learning what exchange is wanted, the B operator presses a key to add five impulses to one of the digits transmitted and thereby to control the marker to direct the call to the wanted exchange. The B operator may cancel a registration by pressing a key 644. The B position can be released by operation of a key 603 once if a registration has been made or twice if no registration has been made, a relay 534 being operated and a re-order signal being transmitted to the marker. The marker is described in U.S. Specification 2,232,371. Selection of sender and operator's position. The sender is seized by application of ground to conductor 111 to operate relays 500, 502. The exchange M, to which the junctor 101 gives access, is marked by ground on a conductor 118 of a group 118 ... 121, and is recorded by relay 208 of a group 208 ...211, 212. The identity of the frame in which the junctor is located is registered by operation of relay 301 or 304 over conductor 506 or 507 and by operation of a select magnet 704, over conductor 503, and a hold magnet 410 in the crossbar register. The link control circuit (not shown in detail) tests the registration and operates relays 206, 200 over conductors 510, 210. The relays lock and hold the registrations independently of the link control circuit which is now released. Relay 200 also operates a hold magnet 411 in the cross-bar register, operates relay 230 to complete signalling circuits over the four wires 227, 228, 232, 233 connecting the sender sections and operates a junctor relay (not shown) to complete the talking circuit to the sender. In the B operator's position, relay 604 is operated whenever an operator is in attendance and applies battery over test wire 600 to a contact of switch bank 906 to mark the position idle. When relay 230 operates, relay 912 follows in the control section over a loop including conductors 227, 228. Relays 913, 914 operate and conductor 920 is grounded to operate a relay 908 and a magnet 907 which together step the switch 900 until an idle position is found. Relay 916 then operates to stop the switch and locks. There are six banks in the finder switch, two (901, 902) for speaking wires, one (906) for test wires and three (903 ... 905) for register conductors. When 916 operates, 919 and 915 follow and the call is indicated to the operator by a flashing lamp 609. Relay 611 is operated over the speaking wires by battery at 926 and ground at 1001. Relay 629 follows and connects tone from 616 which is heard by both A and B operators. Relays 618, 623, 617 interact to limit the tone to two pulses and to change the flashing of lamp 609 to a continuous glow. Registration of digits. When relay 618 operates, it is followed by operation of 602 and release of 916, 919 to extend register conductors 929, 932, 933 from the operator's position to the register, Fig. 11, in which relays 1115 and 1116 to 1145 and 1146 operate. Lamp 648, which was lit when the position was seized is extinguished to indicate that the register is ready. The register includes four digit registers 1110 ... 1140. The operator, having ascertained the wanted number sets it up on the key-set 640. The digits 5-9 are distinguished from the digits 0-4 by a high resistance 647 which prevents the operation of one of the marginal relays 1114 to 1144 in the register over conductor 933. The digits of each group 0-4, 5-9 are distinguished by high and low resistance battery signals over conductors 929, 933. When a digit is registered 1102 operates and adjusts a chain circuit over 1115 ... 1145 to connect the operating wires to the next digit register. When the fourth digit is registered, relay 1000 operates and prepares the circuit for the transfer of the number to the terminal section and for the release of the position circuit. Transfer of registration from central section to terminal section. With relay 1000 operated, stepping relay 1004 is operated in a circuit over wires 232, 233 and over contacts of relay 1027, battery being supplied through the winding of 310 and ground through the winding of 514. Relays 514 and 530 operate and release alternately and generate pulses which are followed by 1004. At the terminal section, relay 312 operates and releases alternately in response to successive releases of 530 and ground from relays 306, 308 is fed to the counting relays 321 ... 326 over the back and front contacts of 312 alternately. The counting relays operate in the order 1 ... 5, 5 and 6, 6 and 1 ... 6 and 4, At the central sender, impulses are counted by a group of relays 1020 ... 1026 associated with relays 1010 ... 1016. The relay at which the count starts is determined by a digit register (1110 ... 1140) and the end of the count is determined by the operation of 1027 which opens the impulsing circuit over conductors 232, 233. Relays 1030, 1031 were operated by 913 when the control section was first seized and remain operated during the transmission of the first digit. At the end of the digit, the next pair of relays 1032, 1033 operates and the first pair releases, the digits being counted in effect by the operation in turn of the relay pairs 1030, 1031 ... 1038, 1039. For a digit n, the control sender transmits n + 1 impulses. The digit 10 is represented by one impulse. The thousands and hundreds digits are translated into three digits determined by registers 1110 alone, 1110 and 1120 together and 1120 alone. The tens and units digits are transmitted as they are registered on registers 1130, 1140. When the impulsing circuit is opened at the end of a digit the impulse counting relays 321-326 transfer the digit to the crossbar register by operation of a select magnet and a hold magnet for each of the five digits. The hold magnets are operated in the order 411, 412, 413, 414, 415, magnet 410 having already been operated as described, to register the junctor frame number. When the hold magnet 415 is operated, relay 520 follows, the four-wire circuit between the sender sections is opened by relay 230 and the terminal sender is returned to normal. The marker, Fig. 8 (not shown), is seized by battery over contacts of relays 576, 520 and over cable 536. The registered number is transferred to the marker which completes the connection and operates relay 516 to start the release of both the sender and the marker. To transfer the registered number, ground from a back contact of relay 762 marks the number over the operated crosspoints and cable 536. This marking is not effective in the marker until the marker returns ground over conductors 801 to 804 to test the circuits and then removes the ground. Relay 805 in the marker (not shown) is operated or. released with the operation of 212 or 208 to direct the call to exchange N or M. Junctor giving access to two exchanges. If the junctor 103 is selected, the call proceeds as before until relay 211,.operates to indicate that the junctor gives access to two exchanges. Relay 211 reverses battery over wires 232, 233 in the impulsing circuit and operates relays 1002, 1003 at the control section. During the interval between the operation of 923 and the release of 919, 624 is operated and a lamp 655 indicates to the operator that an office indication will be necessary. The lamp signal is accompanied by a single prolonged tone. The operator presses a key 651 or 652 to direct the call to exchange M or N. A polarized relay 925 or 924 follows and the identity of the wanted exchange is recorded on relay 942 or 940. Relay 940, when operated, modifies the counting circuit so that five pulses are added to the second of the five digits transmitted to the terminal register. When a digit of five or more is recorded under the control of hold magnet 412, ground is applied directly to conductor 761 and relay 805 in the marker (not shown) is operated over a contact of 211 to direct the call to excha