Patent GB-338125-A (GB)
Title: Improvements in or relating to telephone systems
IPC: H04Q3/58
Filed: 1929-08-09
Abstract: 338,125. Automatic Telephone Manufacturing Co., Ltd., and Gillings, C. Aug. 9, 1929. Automatic exchange metering systems.-In a satellite system in which a call from a satellite subscriber is set up under the control of a codetranslating register-controller at the main exchange, the register-controller sends out an extra digit indicative of the zone of the wanted subscriber to a recording-device at the first code selector, this extra digit serving to select an appropriate impulse sender whereby at the end of conversation a corresponding number of impulses is transmitted over one conductor of the two-wire junction to operate the calling subscriber's meter. The other conductor of the junction is used to control the holding of the junction until the metering operations are completed. The extra digit is sent out prior to the routing digits and may operate the vertical magnet of the first code selector whereby by means of an extra vertical wiper the extra digit results in the operation of one or more storage relays the selector then being released in order to respond in the usual way to the first routing digit. Alternatively the extra digit may be recorded on a single-motion switch associated with the first code selector. Zone metering of calls from a main-exchange subscriber is controlled in a similar manner but takes place when the called subscriber replies. In the system shown, a calling satellite subscriber is connected over a. finder to a repeater, Fig. 1, and thence over a two-wire junction 6, 7 to a first code selector, Fig. 3, at the main exchange. Certain features of the system shown are claimed in divided Specification 338,127. Establishment of connection. Relays RA, RAB, RB, Fig. 1, operate and complete a bridge including relay RD across conductors 6, 7. At the main exchange, relays L, B, operate completing a loop through relays I, D for relay A which energizes relays C, MD, whereby a starting circuit for magnet FDM of the hunting switch FS is closed over a normal contact of the test wiper 33. When an idle A-digit switch is found relay K operates in series with magnet FDM, energizes relay BA, and switches over relay A to the out-pulsing leads 22, 23. Dialled impulses are repeated bv relays RA, L, to the A-digit switch and register-controller over wiper 31. The extra meter-controlling digit sent out by the register-controller is repeated by relay A to vertical magnet VM and at the end of the digit the relapse of relay C completes a circuit over vertical wiper VW for one of the metercontrolling relays 3Z, say, assuming the extra. digit to be 3. Relay 3Z locks up and completes a circuit over off-normal contacts N2 for release magnet ZM. When release is complete, the opening of contacts N2 causes relay 1Z to energize in series with magnet ZM which releases. Relay C operates again over contacts N3 so that the first routing digit operates the vertical magnet VM as usual and on the relapse of relay C, relay G co-operates with the rotary magnet RM to control hunting. When an idle outlet has been found, relay H operates releasing relay A. When all digits have been sent out, relay K releases to complete the talking circuit and when the called subscriber replies relay D operates releasing relay MD and operating relay BR which reverses the current over the junction to operate relays RD, RDR. Relay RDR locks up and holds relay RB. Release; metering. When the calling subscriber hangs up, relays RA, RAB, RD, L, B, release. When cam S, Fig. 8, connects ground to lead 29, relay MS operates so that the subsequent connection of ground to lead 30 by cam Z operates relay MZ which connects lead 26 to conductor 7. Cam 3, Fig. 8, thus transmits three impulses to relay RMR, Fig. 1, which repeats them over a fourth wire M or as booster impulses over a third wire to the calling subscriber's meter. When ground is removed from lead 30 relay MS releases, but relay MZ remains locked over off-normal contacts N4. Battery is thus connected over conductor 6 to .energize relay RMZ which unlocks relay RDR and releases relay RB. The release of relay MS also unlocks relay BR which releases relay BA whereby the release magnet ZM operates and the first code selector returns to normal. Modification employing a single-motion switch associated with the first code selector for recording the wanted zone. The circuits are very similar to those shown in Fig. 3. The stepping magnet of the single-motion switch and the vertical magnet VM are associated with the back contact of relay A over front and back contacts respectively of an additional slowrelease relay (ZC, Fig. 4, not shown) which is operated over a normal contact of a wiper of the single-motion switch and remains locked over the back contact of relay A during impulsing. The impulsing leads 24 - - 28 are associated with conductor 7 over another bank of the switch. Zone metering for call from main-exchange subscriber. The circuits are similar to those shown in Fig. 3, but the metering impulses are transmitted over a third conductor as booster impulses, or over a fourth conductor, and the transmission of the impulses is initiated on the reply of the called subscriber by the release of relay MD, the circuit of the upper winding of relay MS including front contacts of relays B and H. Specification 233,007 is referred to.