Patent GB-513228-A (GB)
Title: Improvements in or relating to telecommunication exchange systems
IPC: H04M15/38
Filed: 1938-04-01
Abstract: 513,228. Automatic exchange systems. STANDARD TELEPHONES & CABLES, Ltd. and WRIGHT, E. P. G. April 1, 1938, No. 10092. [Class 40 (iv)] In a system in which an automatic ticketing machine is taken into use at the termination of a long-distance call to print various information regarding the call, the originating time of the call is derived from the termination time by subtracting the duration of the call which is recorded in the conversation circuit. This operation is performed by common calculating apparatus which is taken into use at the same time as the ticketing machine and which is capable of association with a number of connections terminating at the same time even though their durations may be different. The electric calculating apparatus per se forms the subject matter of specification 513,248. The apparatus comprises an hourswitch H, two ten-minute switches T1, T2 and five minute switches A-F (only A, B being shown in full) advanced from a master clock by means of relays HR, TMR, MR. The contacts of the 10-point 10-wiper switches A-F are connected as indicated to marking wires 0-49 multipled over the 50-point duration switches of the conversation circuits. The contacts of the 10-point switches T1, T2 are connected as indicated to control groups of relays A-F which ground the wipers of the corresponding switches. The operations take place during one cycle of a sequence switch S, which advances automatically when relays ST, IG energize upon seizure of the apparatus. Relays HR, TMR, MR lock if they operate while S is off-normal and do not step the time switches until S again reaches normal. Digits are sent to the printer in the form of code impulses over wires L1-4 by means of relays. W1, W2, W4, W8 which operate singly for the digits 1, 2, 4, 8 and in combinations for other digits, e.g., W1, W2, W4 for 7, W2, W8'for 0. In position 2 of S, the wipers of T2 and wiper hm4 are grounded over wires TL1, TL3 to send the first digit of the preceding hour if the duration is greater than the number of minutes past the hour of the terminating time. Assuming that the time is 24 minutes past the hour, T2 is in position 3 and relay groups D, E, F ground wires 25-49 over the corresponding switches. If a duration switch records 25 minutes or more therefore, a comparison relay operates to connect the code responsive relays to wires L1-4, and ground over wiper hm4 and wire C1 or C48 operates W1 or W4, W8 to send the digit 1 or a space signal thereto. In position 4 of S, relay T is up and the wipers of T1 and wiper hm3 are grounded over wires TL1, TL3 to transfer the first digit of the actual hour if the duration is not greater than the number of minutes of the terminating time. With T1 in position 3, relay groups A, B, C ground wires 0-24, and ground over wiper hm3 operates W1 or W4, W8 as before. In position 5, a signal is sent over wire PL to effect printing. Similar operations take place as regards the second or only digit of the hour, except that wipers hm1, 2 are effective instead of hm3, 4 and control over wires C1-0 the transmission of the actual or preceding hour digit by W1-8. A space signal is sent in position 10 of S. The tens digit of the minutes is sent in four stages in positions 12, 14, 16, 18 in which W1, W2, W4. W8 operate in turn and certain wipers of T1, T2 are connected up in turn by M, N, P, Q. Assuming again that the terminating time is 24 minutes past the hour, so that T1, T2 are in position 3 and A-F are in position 5, wires 5-14, 25-34, 45-49 are grounded in position 12. If a duration switch stands in any one of the corresponding positions, the code responsive relays are connected up to receive an impulse from W1. Different combinations of wires are grounded in positions 14, 16, 18 to allow the receipt of impulses from W2, W4, W8 when required, and the code responsive relays are finally set in accordance with the complete digit, which is printed in position 19. The units digit of the minutes is also sent in four stages in positions 20, 22, 24, 26 in which W1, W2, W4, W8 operate in turn and certain wipers of A-F are connected up in turn by corresponding members of the relay groups A-F. Thus in position 20, relays A1, B1...F1 connect up all the odd wipers, and in the assumed case, an impulse is received from W1 if a duration switch stands in an odd position. The code responsive relays are again finally set in accordance with the' complete digit, which is printed in position 27. When the tariff depends on the time of day, wipers hm5, 6 are provided to apply full ground, resistance ground or nothing to wire KL in position 2 or 4 of S according as the originating time is in the preceding hour or in the same hour as the terminating time.