Patent GB-940221-A (GB)
Title: Improvements in or relating to data registration systems
IPC: H04M1/27495
Filed: 1960-12-22
Abstract: 940,221. Automatic exchange systems. WESTERN ELECTRIC CO. Inc. Dec. 22, 1960 [Jan. 5, 1960], No. 44067/60. Heading H4K. In a selection circuit, associated with a keyboard at a cordless P.B.X., first and second outputs of the circuit (corresponding to the tens and units digits of an extension number) are connected automatically and sequentially over a group of connector conductors to first and second sections respectively of a register. The first and second outputs each consist of a group of conductors-corresponding to the digits 1-0, one conductor in each output group being marked (by ground) when a key is operated. Then, in turn, the tens and units (first and second outputs) conductors are connected to a two-store register, the marked conductors in each case causing the operation of corresponding storage relays in the register so that output conductors of the register are marked for subsequent operations involving the extension of an incoming call to the called subscriber. It is stated that the only operator action now required is the operation of the appropriate extension key and that the operation of hold keys and impulse transmitter is no longer necessary. General description.-The present invention is described as being for use in conjunction with a cross-bar switching system of the type disclosed in U.S.A. Specification 2,904,637. In the drawings, make contacts and break contacts of relays are represented by a cross " X " and bar " 1 " respectively drawn on the pertinent line with a reference to the relay concerned alongside, e.g. make contact 12 of relay U is shown as U * 12. A keyboard selector circuit is shown in Fig. 1, the keys being indicated at K11-K00, the " tens " output being the group of conductors marked TK1-TKO, and the " units " output group being marked UK1- UK0. The keyboard is connected to a register (Figs. 2 and 3) over a group of conductors C1-C0, the " tens " output being extended horizontally to "tens" register relays TD1-TD0 and the " units " output being extended vertically to " units " register relays UD0- UD9. Finally, one lead in each of the groups T2-T0-T0-0 and U0-0-U9-0, is marked for allowing the call to be completed through the P.B.X. Particular description.-The operator, upon ascertaining the extension to which an incoming call is to be extended, operates the appropriate key, say K40. This causes ground on bus GRD to be applied to wires TK4, UK0 and energizes relay C. Relay HP pulls up, followed by HPI with subsequent release of HP. The momentary operation of HP causes: (1) a register and marker circuit to be associated with the keyboard; (2) the operation of relays SR and ON (not shown) in the register; (3) the energization of a relay RAOA and one each of the sets of relays TRC0, TRC1 and RGA, RGB (all not shown and all in the line, link and marker circuit. Fig. 3) and hence the energizing of relay KPC (Fig. 3); and also (4) the operation of some or all of the class of service relays TLD, TLA, COT, TTR (in this case only the first three). The marker circuit then releases from the register but relays SR, ON, TLD, TLA and COT therein remain held. The operation of KPC connects the conductors C1-C0 to the register and extends control channel KRA (Fig. 1) to key register advance relay KRA in the register. Hence the ground condition on conductor TK4 allows relay TD4 to pull up, which then holds and marks (grounds) wire T4-T0 in the output of the register. A relay P2A (Fig. 3a, not shown) pulls up and holds when KRA operates, this action being necessary to over-ride a pulse storage circuit (Fig. 3a, not shown) which may be associated with the P.B.X. when " operator dialling " of an extension number is used. Relay KRA also guards against registration of spurious " line opens " which was accomplished in the Specification referred to above by delayed operation of P2A. Slow operate relay T (Fig. 1) now comes up to open the connection between conductors TK1- TK0 and C1-C0,and that between the control channel KRA and relay KRA. Hence relay SW (Fig. 3) pulls up followed by STR (Fig. 2). Steering relay STR locks up and transfers the register input on wires C1-C0 from the " tens " digit relays to the " units " digit relays UD0- UD9. Eventually, slow operate relay U comes up, thus completing the connection between units conductors UK1-UK0 and the " units " relays and because of ground on UK0, UD0 pulls up, thus marking wire U0-0 in the second output of the register. Energization of U also re-operates KRA, hence cutting-off SW, and operating relay UD which then locks up. After a short time slow-operate relay S comes up to release KRA. The latter completes the circuit for a relay DC which releases KPC and thus in turn relays T, U and S, and also severs the connection between the key pulse circuit (Fig. 1) and the register (Fig. 2). The operation of DC also recalls a marker circuit to the register so that the now-registered call can be extended and operated relays in the register released. When the called party is being run or answers, or if he is busy (all of which can be signalled to the operator by any of the usual means), she releases key K40 so that the still-operated relay C may relapse. The key pulse circuit is thus restored to normal.