Patent GB-671673-A (GB)
Title: Several-code numbering-signal reception device applicable to long-distance communications
IPC: H04Q3/42
Filed: 1949-04-08
Abstract: 671,673. Automatic exchange systems. COMPAGNIE INDUSTRIELLE DES TELEPHONES. April 8, 1949 [April 8, 1948], No. 9575/49. Class 40 (iv). In a register-controller system in which numbers may be sent over different lines according to different codes a register responsive to one code is normally connected up and one of a plurality of auxiliary registers responsive to other codes may be temporarily associated with the first register to receive digits and control the first register in accordance therewith. As shown, the subscriber's line is connected over a line finder CA, a link circuit CC, and a link finder CH to the main register. An auxiliary register finder RE connects up the auxiliary registers when required. It is assumed that a call has been initiated and that the main register has been seized. The register start relay 5 (Fig. 2), and the hold relays 3, 4 are therefore up and the driving-magnet of the descriminator D1 is energized. The line equipment relay C pulls up and with the discriminating lead 202 wired to position 0 of D1 relay 1 operates immediately over bank a to stop D1 from stepping. Ground is thus extended over bank c of D1 to the start wire MM of the auxiliary registers and to relay 5 in parallel therewith. In the auxiliary register (Fig. 3) start relay MR pulls up and relays 1 and 2 follow to drive finder RE to the calling register, ground over wiper M releasing the differential relay 2 thus stopping the finder. The resulting operation of relay 3 causes relay 4 to pull up to the calling loop and bring up relay 5. Relay 3 is then held in series with relay 2 (Fig. 2), which removes ground from MM and releases relay 5 (Fig. 2). Dial tone from wire t is returned over bank b to D1 to the caller. In the auxiliary register the lower winding of pendulum relay 6 is energized. This relay is such that when the lower winding is energized it closes its contact y, when the upper winding is then energized the relay releases and the plate 61 oscillates at a period of 50 m sec., contact x closing after 25 m secs. The incoming signals are four-unit code signals, each signal element being of 50 m secs. duration, the space condition being current in the loop and the mark condition no current in the loop. Relay 4 relapses to the " start " signal of the first digit and relay 6 is released, the closure of contact x bringing up relay 9 over bank j of Y. The electromagnet of switch Y is energized and when relay 6 closes contact y relay 11 pulls up and opens the circuit of Y, whereupon it advances to position 1. Contact x is then reclosed just as the first code element is signalled. If this is a mark relay 4 relapses and condenser CO is charged so that when relay 7 pulls up it discharges through the left-hand winding of relay 8 which operates and brings up register relay a. Relay 6 re-closes contact y,whereupon relay 7 relapses and 11 re-operates to step Y to position 2. The cycle is repeated relays b, c, and d being operated if the second, third and fourth elements are marks. When relay 7 operates to the fourth element it brings up 10 over bank k of Y in position 4 which opens the charging circuit of CO and releases 9, whereupon relay 6 is re-energized to bring up 11 and step Y to position 5. Operation of 4 to the " stop " signal releases 10 and the second digit may be received. Relay A pulls up over bank k in position 5 and holds under control of the operated register relay(s). The second digit is registered on relays e, f, g, h. Transfer of digits to main register. Assume the first digit to be 5 (mark, space, mark, space) and register relays a and c to be operated. On the operation of A (Fig. 3), the driving magnet of the first digit register X (Fig. 2) is energized over bank a of the digit distributer DE and wiper R of RE and at the same time relay 6 (Fig. 2) pulls up and energizes the magnet of DE. Register X steps to the contact of bank a marked by the register relays a to d (Fig. 3), whereupon relay C (Fig. 3) operates. Register X is stopped, relay 6 (Fig. 2) and the operated register relays a and c (Fig. 3) release followed by relay A (Fig. 3). Succeeding digits are dealt with in like manner.