Patent GB-531205-A (GB)
Title: Improvements in or relating to telecommunication exchange systems
IPC: H04M15/08
Filed: 1939-06-30
Abstract: 531,205. Telegraph exchange systems. STANDARD TELEPHONES & CABLES, Ltd. (Haigh, L. B., Rousseau, E. J., and Clemens, P. J.). June 30, 1939, No. 19115. [Class 40 (iii)] In a system in which a call is set up over a finder-connector link LF, S with the help of a register-controller, automatic ticketing apparatus TP associated with the link receives from the register-controller first the number of the calling line, as determined by a finder IF provided for the purpose and then the number of the called line. A timing-switch SM sends metering impulses to the ticketing apparatus periodically while the connection lasts. Establishment of call. Relay RSr energizes when the finder LF is in engagement with the calling line, and the operation of relays Rc1r, Rc2r, Rc5r or Rc3r, Rc4r, Rc6r takes into use a registercontroller in which Rhr pulls up. Dialled impulses are repeated by Rr1 to -Ir to set the. registers SM1-3, change-over being effected by Clr, C2r, and relay Edr operates at the end of dialling. If the first digit indicates a local call, a circuit is made for Sar, Sbr over SM1(b), and the connector S moves to the wanted-line in two stages under the control of markings supplied over SM2(c), SM3(c). Relay Gtr responds to the marking and connects up Scr, Sdr at its first operation and Esr at its second operation. Assuming the line is idle, test relay Str connects up Rbr. which in turn connects up switching relay Thr of the link and releases the register-controller, provided it has transferred its records to the ticketing apparatus. If the first digit indicates a junction call, a circuit is made for Ocr, Lor; and the connector S hunts for an idle junction of a group marked by SM1 (c). Test relay Gtr connects ub Shr, Oxr, and relay Rir responds to + over the a wire of the junction when the distant apparatus is ready and connects up Opr. Three trains of impulses are now sent over the b wire by Osr under the control of impulse generator IS. A switch SM4 which counts the impulses is controlled in turn by markings over SM1(c), SM2(c), SM3(c) and terminates each train. Relays Cxr, Sar, Sbr energize after the hundreds digit, Scr, Sdr after the tens digit, and Esr after the units digit, the last relay connecting up Rbr. Control of ticketing apparatus TP. Upon seizure of the register-controller, the finder IF hunts for the calling line which is marked over wiper e of LF, and Itr pulls up. Relay Idr is connected up by Rar which is controlled from TP, and Tar now starts impulsing from the generator IS, impulses being repeated by Tsr to TP and to a counting switch SM6. The hundreds digit of the calling line is determined by an invariable marking, and the tens and units digits by markings over wipers b, c of IF, the markings being applied in turn by a sequence switch SM5. Relay Ttr operates to end each impulse train and controls Dfr, to effect printing. Provided Edr is up, indicating that dialling is finished; the digits of the called line are transferred in a similar way under the control of SM1(d), SM2(d), SM3(d). The operation of switching relay Thr starts a timing Switch SM, which is stepped by clock control every 18 seconds. A circuit is made after the first 'step, and then after every ten steps, for Dfr to effect printing by TP. Arrangement of links and register-controllers. The links are arranged in three groups which are served by three register-controllers in such . a way that each register-controller is first choice to one group and second choice to another group. To avoid cross-connections, the connectors S have two marking banks d; e' which are adapted to be controlled respectively by the first and second-choice register-controllers associable therewith. Similarly, the finder IF is adapted to hunt over -either of wipers a, d for + or - potential, dependent on the condition of Rxr, Chr, these relays as well as Rhr being controlled over wires 1-5 by the associating relays. Specification 472,434, [Group XXXIX], is referred to.