Patent GB-361849-A (GB)
Title: Improvements in or relating to telephone systems
IPC: H04Q3/00
Filed: 1930-08-21
Abstract: 361,849. Automatic exchange systems. AUTOMATIC TELEPHONE MANUFACTURING CO., Ltd., Strowger Works, GILLINGS, C., 28, Eldred Road, Mossley Hill, and BELAS, F. T., 24, Stanley Street, all in Liverpool. Aug. 21, 1930, No. 25066. [Class 40 (iv).] The sending switch of a code-translating register controller is employed to record the B digit and the sender-control switch to record the C digit, the records being transferred to a translating switch in which adjacent sets of terminals represent alternative routes to the same office. The sending switch also times the pause between digits and the period allowed for releasing a partially established connection. Registering number translating arrangements. When the register controller is seized, A, B, BA pull up. A repeats the digits to the sending switch S (wipers 1b .. 5b), sender control switch C (wipers 1c .. 6c), and digit registers TH (wipers 1e, 2e), HU (wipers 1f .. 3f), T (wipers 1g .. 3g), U (wipers 1a .. 5a), the last-mentioned acting under control of relay C as the digit distributer. Relay N replaces the off-normal contacts of the usual BC switch. One or two code switches FC (wipers 1d .. 8d), FD (wipers not shown) are employed, the alternative circuits being shown in chain-dotted and dotted lines respectively. When the B and C digits have been recorded a circuit is made over 2a for IG which, when next the springs HPS open, locks up and drives FC until a circuit involving wipers 5b, 4c is found for FA which locks and releases IG to home the sending switch and control switch in turn after which HB initiates the transmission of the digit as described below. If a busy condition is encountered D operates intermittently in response to a low-frequency signal pulling up, falling back and pulling up again while the sending switch wipers move over contacts 14-21 to time the hunting period and energizing in turn AR, BR, CR. The last connects low-resistance ground via BR to wire 14 to release the first code selector, energizes the driving magnet of the code switch, and drives the control switch via AR to its second starting position. When the first code selector is released, BR releases CR (AR having fallen meanwhile) and the code switch moves its wipers, the terminals now encountered providing the alternative translation. Transmission by register controller. HB makes a circuit for IG which when next springs HPS open connects them to SDM to drive the sending switch which after two steps removes a short-circuit from the loop springs LPS. When 4b encounters the marking potential the springs are short-circuited by SZ which locks up, cuts off IG and makes a circuit for driving the sender switch rapidly to its fourteenth terminals (and from terminals 22-25) and for stepping it by interrupter impulses from 14-22 to allow hunting time. SZ also allows the sender control switch to move its wipers. When the sender switch reaches home, SZ falls re-energizing IG and the next digit is sent. Release of register controller. When the control switch reaches its eleventh (or twenty-second if rerouting has taken place) terminals, CO pulls up, locks and sends the switches home in turn, the restoration of the last releasing N. Zero calls. A-digit switches seize register controllers on the tenth level with the leads 12, 13 reversed. D therefore responds energizing MB which causes the code switch to be stepped to its final terminals to select the code for routing to an operator. Standstill releases. If the subscriber delays in dialling, the " S " relay TP will be held long enough for M to receive a ''Z" pulse. M opens the impulsing loop, connects up 19 and energizes HB. When next springs MPS operate IG makes the driving circuit for the sender switch which moves to its thirteenth teminals and then energizes SZ which earths the forced release wire 15. If a spare code is dialled the code switch, failing to find a marking potential, energizes AR, BR the first time it reaches its last terminals and M the second time and forced release then ensues. Zone metering. The first digit sent by the register controller may control metering. In such a case the control switch has a wiper 5c which, when the metering train has been sent, grounds the rerouting wire 14 to operate a relay in the A-digit switch. , The Provisional Specification describes with reference to drawings a similar register controller in which the test relay FA of the code switch is a shunt-field relay relying on two simultaneous circuits in place of the series circuit, and differing in other minor respects from that described above.