Patent GB-656563-A (GB)
Abstract: 656,563. Automatic exchange systems. WESTERN ELECTRIC CO., Inc. Feb. 20, 1948, No. 5099. Convention date, May 15, 1940. [Class 40 (iv)] Two 10,000 line cross-bar exchanges A, B, Fig. 1, situated in the same building employ common register senders 500 and markers 600 and common switches 700, 701, 900. Some incoming junctors 400 are used for calls to one exchange only and others are used for calls to either exchange. The code and numerical digits of a wanted line 930 are registered in a sender 300 at a calling exchange and when the call is extended by means of a marker 302, the numerical digits are transmitted by revertive impulses to an idle terminating sender 500 common to both exchanges A, B. A transfer relay 601 in the terminating marker 600 routes the call to either A or B. If the junctors 400 are individual to the exchanges A, B, the transfer relay is operated by a marking from the selected junctor. If the junctors are available for calls to either exchange, the transfer relay is controlled by the sender 500 in accordance with an exchange digit registered therein. The originating sender 300 transmits the recorded tens and units digits to the sender 500, but translate the thousands and hundreds digits into three digits, one of which, the exchange digit, falls in the range 1-4 if the call is for exchange A and in the range 6-9 if the call is for exchange B. The transfer relay 601 is operated by the sender if the exchange digit registered is 6-9, and the call is routed to exchange B. Figs. 4-9 should be arranged as shown in Fig. 10 to show the circuit of the two exchanges A, B. Junctors individual to exchanges A, B. Junctors 400, 402 allotted for calls to A, B are connected to group start relays 407, 417 respectively. The lower contacts of relays 408, 418 are patched to ground so that the operation of 407 or 417 leads to the operation of 507 or 508 over contacts of 409 and 502 operated when the sender is seized. With conductor 602 patched to conductor 629, transfer relay 601 is operated or released with the operation of 508 or 507. Conductor 520 is patched directly to relay 512 which operates and conditions the sender for operation. The digits are transmitted from the originating sender 300 to the terminating sender 500 over a trunk 215, a junctor and switches 404, 405 and the sender 300 is released. Junctors common to both exchanges A, B. The patchings at 412 and in sender 500 are so arranged that the operation of any group start relay 407 or 417 is followed by operation of relay 509 and either 507 or 508. The sender conditioning relay 512 is operated over contacts of these relays and of 510 and locks under the control of an off-normal relay 511. The digits are transmitted and the sender 300 is released as before. In the cross-bar register 530, crosspoints 514 for the exchange digits 6-9 are patched to ground so that transfer relay 601 is operated over a contact of 509 when one of the digits 6-9 is registered as an exchange digit. Terminating marker, identification of number terminals in number group frame 707. The digits registered in the sender 500 are transferred to the terminating marker 600 over a marker connector 501 and are recorded on four groups of ten register relays, the groups being represented by a thousands relay 605, a hundreds relay 606, a tens relay 607 and a units relay 608. The hundreds relay 606 operates a relay 610, of which there are five associated with each hundreds relay, and operates a relay 609 to indicate whether the digit is greater or less than five. Over contacts of 603 or 604 the thousands relay 605, in combination with 609, operates one relay 613 of two sets of twenty relays. Each relay 613 represents a block of 500 numbers and the two sets of relays correspond to the same numbers in the two exchanges A, B. Either relay 603 or relay 604 is operated by the transfer relay 601 to determine the exchange in which the selected number group is wanted. A marker relay 705, followed by 708, 709 is operated over contacts of 610 and 613 to mark a number group frame 707 corresponding to a block of 100 numbers. As a number of markers have access to the same number group frame, the marker relays 705 are included in a chain circuit so that only one marker can attach itself to the frame. The tens relay 607 identifies blocks of twenty numbers by operating 617, 618 and also discriminates between odd and even digits by operating 616 for odd digits. The twentyblock relay 710 is operated over contacts of 618, 705, 708, 709 and twenty sets of three terminals 711, 712, 713 ... 714, 715, 716 are marked in the frame. The terminals 711 and 714 are connected over jumpers 724 to the positions assigned to the lines 930 in primary switches 901 and the corresponding busy test relays 621-622 of busy lines are operated. Terminals 712, 713 of the individual wanted line are marked with ground by operation of a selecting relay 619 over conductor 625 and contact of tens and units relays 616, 608. Connection of wanted line. The lines are  arranged in levels, frames and choices, a choice including four frames and frame including ten levels. The choice is marked by operation of one of ten relays 800. The frame and the level are marked by energizing one winding of twenty double-wound relays 802 allotted to the choice, followed by relays 814, 818 if the frame is idle. Relays 800 and 802 corresponding to the wanted line are operated by ground on terminals 712, 713 of the number group frame, the terminals being jumpered as necessary to strips 720, 717. Relays 800 have three windings which are so energized as to indicate whether the line is an individual line, a P.B.X. line, or a party line and if the line is a party line to indicate whether the station is connected to the tip wire or the ring wire. Marker relays 908, 909 are operated and the switches follow to complete the connection as described in U.S.A. Specification 2,232,271.