Patent GB-472402-A (GB)
Title: Improvements in or relating to telephone or like systems
IPC: H04M15/38
Filed: 1936-03-20
Abstract: 472,402. Automatic exchange systems. STANDARD TELEPHONES & CABLES, Ltd., WRIGHT, E. P. G., and LOWRY, L. P. March 20, 1936, No. 8383. [Class 40 (iv)] In a system in which information used for computing charges for calls is recorded on machines available in common to connections set up from a number of substations, a machine is held in use throughout the conversation only when necessitated by the nature of the information due to the kind of call. In the system described, calls may be set up to a subscriber at a tandem exchange or to rural exchanges nearby and distant from the tandem exchange, the recording equipment being at the tandem exchange. In the first kind of call, the recording equipment is taken into use until a discriminator at the incoming repeater at tandem determines that the call is local. In the nearby rural call the equipment is taken into use until a further discriminator in a control circuit of the recording machine releases it, recording equipment being reconnected at the end of conversation to record a code digit, which has been stored by the discriminator at the repeater, together with the number of the calling subscriber, time of day, date, and serial number of the ticket made by the machine. In the case of a distant rural call, the equipment is held in use throughout conversation to record the numerical digits of the wanted party, and to store in a recording control circuit, a code digit of the wanted party (another one is stored at the repeater), the reply signal and first 3-minute period of the conversation, and minute intervals in excess thereof. At the end of conversation, the code digits are recorded on the machine for tariff assessment followed by the number of the calling party, time of day, date, serial number and the minute intervals, if any, in excess of three. Provision for recording the duration of conversation during the conversation, and also the calling number (by voicefrequency signalling) is referred to. The nature of the record may also depend on the group of junctions or other speech circuits to which the equipment is connected. Variation of the tariff digits sent to the machine may be effected by clock-controlled contacts. The calls are set up over a finder and group selector, Figs. 1 and 2, and an outgoing repeater, Fig. 5, which takes into use equipment, Figs. 3, 4 and 6, for identifying and sending the calling number, to an incoming tandem repeater, Fig. 7, which takes into use a recording control circuit, Fig. 8, having access over switch MFM to a recording machine described in Specification 472,434. The reference numerals of the leads to wipers mfm1 ... 8 are those used for corresponding leads in the Specification referred to. Identifying the calling party, Figs. 3 to 6. Switch RFM, Fig. 6, hunts for the outgoing repeater, Fig. 5, at which operation of OBB, OCC has operated start relay IST. Test relay IT pulls up followed by ITT which releases OBB, and holds OCC and operates start relay FST, Fig. 3, of a line identifying switch FFM in the bank ffm2 of which the calling line has been marked by a voice frequency over VFL and rfm2, Fig. 6, and the c-wire. When the calling line is reached, the voice frequency is applied to valve V1 and anode relay AR pulls up, stops the switch, and operates BR followed by HR, FST falling back. Start relay STR of group identifying switch GFM is now operated and when the line identifying switch is found GAR, GBR pull up and STR falls back. The identification equipment now awaits a signal that the ticketing machine is ready to receive the calling number, this signal causing SPR, Fig. 6, to operate over a loop circuit as described in a subsequent paragraph. DRR follows, locks up, and releases SPR, the next opening of impulse springs IPS permitting ICR to operate and connect DIR to the springs. The sending control switch SMC has odd contacts in bank 1 connected to two sets of 4 leads in parallel, one set leading to bank contacts of GFM and the other set to bank contacts of FFM; the even contacts of bank 2 of SMC are connected to the even contacts in bank 1 and the odd contacts of bank 2 are connected to battery. Wipers gfm1 and 2 engage bank contacts cross connected to the terminals 1 ... 0 in accordance with the thousands and hundreds digits of calling lines, and wipers gfm4 and 5 are standing on leads to wipers ffm3 and 4, the bank contacts of which are cross-connected to further terminals 1... 0 in accordance with the tens and units digits. SMC is stepped by DIR, which also repeats impulses over a loop circuit to the distant repeater, until smc1 reaches the lead connected directly or over a resistance to thousands wiper gfm1 and thence to ground at the digit distributer SMD. If the connection at gfm1 is direct, DFR operates over smc1 in spite of the resistance battery shunt over smc2, and releases 1CR which disconnects DIR from the impulse springs. If the connection at gfm1 is over a resistance, DFR remains inert and SMC takes another step, another impulse goes out, and DFR pulls up over smc2, smd1. The release of 1CR at the end of the digit homes SMC whereupon DFR relapses and back-stroke distributer steps on to the hundreds lead, 1CR being reoperated to connect DIR to springs IPS1. The remaining digits are sent in a similar manner as determined by markings over gfm2, ffm3, ffm4, whereupon ITT is shunted over distributer bank smd1 to release the outgoing repeater and identification equipment. Call to subscriber at tandem exchange. Relays OA, OB at the outgoing repeater, Fig. 5, complete the outgoing loop so that TA, AA, TB at the tandem repeater, Fig. 7, operate whereupon start relay ST, Fig. 8, of a recorder control circuit pulls up and finder TFM hunts for the repeater, T pulling up when the repeater is found. TT follows and causes MFM to pick up an idle ticketing machine. The next digit 3 is repeated by TA forward and also to switch CAM, Fig. 7, and relay IR which disconnects wipers cam1, 2 during the train. When IR relapses, TL pulls up over cam2, locks, and opens the start and test circuits of the recorder control circuit which is released, together with the ticketing machine. The call is completed and when the calling'party hangs up, OA, OB at the outgoing repeater fall back OBB being operated during the release period of OB to energize OCC which connects LJR to the outgoing b-wire and operates start relay IST of the identification control circuit, Fig. 6. At the tandem repeater TA, AA, TB relapse followed by TL during the release period of which battery is connected to the b-wire to operate LJR which releases OBB, OCC and the identification control circuit. Call through tandem to nearby rural exchange. The code digits received at tandem are 55, At the end of the first digit, SR and F operate over wipers cam1, 2 and the second digit is repeated to switch DAM in the control circuit, Fig. 8, which has been connected up as previously described. On relapse of series relay BR, relays VR, X pull up and CAM steps by self-interruption to contacts 11, where Q pulls up and opens the start and test circuits of the recording control circuit which releases. When TA, AA, TB, relapse on termination of the conversation, TL has not been operated, so that BB pulls up, locks, and energizes CC which causes a recording circuit to be connected up. When this has been done CC is held over tfm1 by TT which causes switch MFM to hunt for a ticketing machine, an idle one operating MT which energizes MTT whereupon MT relapses. Relay CSR now energizes and TTR in the repeater pulls up followed by ACR, ADR, impulse relay IIR being connected to springs IMP. Relay IIR impulses the switch CAM and also sends impulses over tfm4, mfm6, to the digit wheel in the ticketing machine, ISR, ISRR being operated during impulsing. The digit sent (5) is determined by the operation over cam3 of EFR which releases ACR to disconnect the impulse springs and when ISR, ISRR release in turn JJR is momentarily energized to operate EDR, FIR which hold over mfm8. FIR grounds mfm4 to effect printing of the digit which as explained in Specification 472,434, will be followed by dashes in place of further digits whereupon the ticketing machine on leaving position 7 removes ground from mfm8 to release FIR, EDR, the machine proceeding automatically to position 10, and printing spacing dashes. Relay NAR has operated and locked in response to the operation of FIR so that when this relay releases NBR pulls up, and as RIR operates when the operating shaft of the machine is normal in certain positions of the machine including position 10, FIR re-operates, holds over mfm8, operates NCR, shunts out NAR, and grounds mfm4 to cause the printing of normal spacing dashes, the machine after releasing FIR proceeding to position 16, NBR being now shunted. When in position 16, the machine operates RIR followed by NDR to energize CCR in the repeater, whereupon the lower winding of TA previously disconnected from ground by CC is again connected up to complete a loop from the identification equipment to initiate the sending of the calling number. The re-operation of TA energizes SR, and incoming impulses are repeated by TA over tfm4, mfm6. When the code digit (wanted number) had previously been sent, the operation and release of ISR stepped a control switch CSM so that when ISR, ISRR and JJR function for each digit of the calling number as described for the code digit, resistance ground over csm2 operates FIR which loops mfm4, 5 to operate the clutch magnet in the machine for effecting printing, EDR remaining inert and CSM taking a step for each digit. When all the digits have been sent, csm2 reaches a directly grounded contact whereupon FIR, EDR both operate and are held by the machine which moves to position 22, FIR, EDR being released after position 21. Ground connected to mfm4 causes the machine to print the time, date and serial number of the ticket, the machine being now in