Patent GB-484568-A (GB)
Title: Improvements in or relating to telephone or like systems
IPC: H04M15/04
Filed: 1936-10-31
Abstract: 484,568. Automatic exchange systems. STANDARD TELEPHONES & CABLES, Ltd. (Hatton, W., Haigh, L. B., and Kozma, L.) Oct. 31, 1936, No. 29638. [Class 40 (iv)] [Also in Group XL] Means for identifying a calling party's line, particularly for transmitting its number to an automatic ticketing machine, comprises two stages of finder switches hunting respectively for the group, e.g. 100's or 200's group, and for the individual line in the group. The invention is described with reference to two arrangements, one of which is described in detail below and the other, in which a 200- point rotary power-driven final selector serving normally for incoming calls is used as the individual-line identifying switch, is identical with that shown in Figs. 4-6 of Specification 484,647. The marking of the calling line and group is effected by alternating current sent back over the established connection from the outgoing junction, the identificationcontrol circuits having thermionic valves for detecting this current and being provided with means by which if a valve is faulty the circuit is released, another one is taken into use, and an alarm is given. Other features of the first system form the subject-matter of Specifications 484,649 and 484,658. Recording called number. On extension of a call over primary and secondary finders 1LF, 2LF, and group selector IGS, Fig. 1, to an outgoing junction, Fig. 3, relays Cw, Jg, Jc, Ri, the circuit for Ri being from ground over lead 5 in the ticketing machine which is similar to that described in Specification 472,434. Relay Jd operates over resistance RST and wiper jsm2, energizing magnet JSM, and relay Jb operates over the outgoing loop, energizing relay Bb which connects the righthand winding of relay Js across the incoming loop. Relay Js operates energizing Jl and Je. At the first impulse of the hundreds digit, relay Js releases and repeats the impulse over relay Si and lead 1 to the ticketing machine. At the same time, relays Jc, Jb are released and an impulse sent over the outgoing junction. To terminate the impulse, on the re-operation of Js, battery at jg4 is connected over contact js1 to the b-wire and ground at jc1 to the a-wire. Relay Jd is released by Si and switch JSM moves to position 2. The remaining impulses are repeated at js1 over the junction and at js2 to the ticketing machine and at the end of the digit the relapse of Si releases Bb, Js, Jl, and Je. Relay Jd and magnet JSM re-operate and ground from lead 2 is extended back over lead 3 to cause the digit to be printed together with two predetermined exchange digits. The removal of ground from lead 5 releases Ri, Jd and switch JSM moves to its third position. Relays Jc, Jb re-operate and when the machine is ready for the next digit relay Ri is re-operated over wire 5, relays Jd, Bb re-operate, and relay Js is again connected across the incoming loop to signal the register-controller to send the next digit. Repetition of the tens and units digits then takes place in a similar manner. At the end of the units digit, marginal relay Nf operates over wiper jsm2 in its 6th position since resistance RST is cut out, connects earth continuously to wire 3 to indicate that no more called-number digits are to be awaited, and energizes relay Es. Relay Ew operates from ground on wire d and connects the windings of Js over earth and battery to the a- and b-wires, respectively, and relay Js re-operates and holds Jl. Relay Nf is released by the ticketing machine. The reoperation of Ri energizes Ac. Recording tariff digits. Relay Ac operates start relays Cs, Is of control circuits, Fig. 4, and when an idle circuit finds the junction, Fig. 3, relay Te operates over wipers cdm1, cjm6, and relay Dt then operates in parallel. Relay Vt operates connecting 500-cycle current to transformer AGT feeding the grid of valve RV, so that anode relay Ap operates energizing Tc which lights lamp LO and releases Vt. Relay Pw operates over wiper cjm1 when relay Ri is energized by the ticketing machine. Relay Ic energizes relay Bd when interrupter INR opens a short-circuit and connects the interrupter to relay Ir which transmits impulses, over wiper cjm3 and lead 1, to the ticketing machine and also to magnet CCM. The end of the first (fixed) digit is determined by the operation of relay Ed over wipers ccm1, cdm3, and three further digits are similarly sent, switch CD being advanced one step for each digit by relay Ed. In the fifth position of wiper cdm3, relay Tf operates and locks in parallel with lamp LA to wiper cdm1. If a different tariff is employed at night, relay Nt, Fig. 4, is energized by clock-controlled contacts to substitute wiper cdm2 for cdm3. Recording calling number. Relay Tf connects 2000-cycle current over wiper cjm5 to the d-wire, Figs. 1, 3, and grounds start lead SVL, Figs. 4, 5, to operate relay Sv which lights the filament of valve DV1. The 2000- cycle current passes over lead 12 to the grid transformer RGT causing the operation of anode relay Rp which energizes relays So, St. The distributer DS is pre-selecting by connection of relay As to test wiper dsm3, relay As when operated by a busy circuit energizing magnet DSM as long as a free circuit is available as determined by the operation of relay Ab. Relay St lights the filament of valve DV, Fig. 2, of the preselected circuit over wiper dsm1 and connects 500-cycle current over wiper dsm2 to operate anode relay A. Relay Str energizes completing a circuit for relay D, Fig. 5, which steps on distributer DS and through a further relay DR cuts off the 2000-cycle current from RGT. The release of relay A operates relay Gt. Magnet CFM now operates to connect switch CF to the circuit, Fig. 1, employed in the connection and when this is reached, the 2000-cycle current on lead 12 passes over wiper cfm8 to operate relay A again. Relay Gf operates releasing Gt, A, and relay Ft then operates and connects ground over wiper cfm7 to relay Fd to cut off the 2000-cycle current. Magnet IFM is energized to step switch IF in search of an idle switch RI giving access to the calling line under the control of relay T which energizes over wipers cfm3, ifm0, ifm9 and battery on lead 8, relay Lt operating to busy the selected switch by connecting up the lowresistance left-hand winding of relay T. Relay Lt also energizes magnet RIM and when the calling line is found by switch RI, the 2000- cycle current on lead passes over one of wipers rima .. rimc, and wipers cfm6, ifm7 to operate relay A. Relay Lf operates, shortcircuiting T and completing a circuit to operate relay Ic when interrupter INT is open. Relay Ic connects the interrupter to relay I and on its first operation, magnet SCM is energized and 500-cycle current from transformer TR is transmitted over wipers ifm7, cfm6 and the d-wire back to valve RV, Fig. 4. Relays Ap, Pi, and magnet CDM operate, and at the end of the pulse, switch CD moves to position 6 in which relay Th operates, opening the start lead SVL and cutting off the 2000- cycle current. When relay I, Fig. 2, releases, wipers scm 1 .. 4 move to position 2 and relay Df operates over wipers scm1, sdm1, scm4 to release Ic and restore switch SCM to normal. Switch SDM moves to position 2. Two exchange digits of 500-cycle pulses are then sent out in positions 2 and 3 of SDM under the control of direct jumperings across the frame and are followed in positions 5, 6 and 7 by the hundreds digit, determined by a jumpering from the bank of wiper cfm1, and the tens and units digits. For values 1 .. 8 of the tens and units digits, ground on wiper scm4 is connected over wipers sdm1 and ifm6 or ifm5 to wiper rimd or rime, the contacts in the banks of which are connected in pairs to leads 4.. 1, directly for odd numbers and over a resistance for even numbers. In the odd positions of switch SCM, relay Df is shunted over wiper scm2 by a resistance which prevents it responding over a resistance in the leads 4 .. 1. Thus, for example, for a tens digit 1, relay Df responds over wipers scm1 (position 1), ifm4, rimd, ifm6, and for a tens digit 2 it responds over wiper scm2 (position 2) when the shunting resistance is cut out. After the last digit, relay Str is short-circuited over wiper sdm2 and the circuit released. The impulses for the digits are repeated by relay Ap, Fig. 4, over relay Pi, wiper cjm3, and lead 1 to the ticketing machine, relay Pi controlling magnet CDM to advance switch CD one step for each digit. After the last digit, direct ground over wipers cdm3, cjm2 operates relay Nf in parallel with Jd. Relay Ps operates, relay Nf connects ground to lead 3 to prepare the ticketing machine for time recording, and relay Ri is then operated from the machine and Nf released so that relay Ac is shortcircuited and releases. The removal of battery from wiper cjm4 releases the control circuit, Fig. 4. Recording duration, time and date of call. When the called party replies, relay Jb. Fig. 3, operates and energizes As. Clock contacts CLC transmit pulses every two seconds, each set of three successive pulses operating relays Fs, Ts, Ss in turn causing magnet JSM to advance wipers jsm1 .. 3 (from position 7) one step every six seconds. In position 8, relay Wp operates and when relay Ac releases at the end of the calling-number transmission, relay Ar operates releasing As, and relay Jd connects ground to lead 3 to cause the machine to punch three holes, representing a first 3- minutes, accompanied by the date, hour and serial number. Relays Ri, Wjp, Jd, release. When wiper jsm2 reaches position 7 on the second rotation relay Tm operates and in position 16 corresponding to the end of three minutes relays. Wp, Jd operate and ground on wire 3 causes the recording of the fourth minute. Owing to the closure of contacts tm3, switch JSM steps immediately to its first position from position 21. For succeeding rotations, therefore, the switch takes 20 steps at 6-second intervals and at each passage ov