Patent GB-669069-A (GB)
Title: Improvements relating to telephone sets
IPC: H04M1/274
Filed: 1949-06-13
Abstract: 669,069. Automate exchange systems. KAELIN, P. June 13, 1949 [June 14, 1948], No. 15643/49. Class 40 (iv). A telephone subscriber is provided at his substation with means for automatically diverting his incoming calls to other substations according to a time-scheme prepared in advance by the subscriber. The recipient substation may be changed at certain intervals of time, such as an hour or a day. The subscriber sets a switch MAH to the interval required, lighting a corresponding lamp LMAH to illuminate part of a dial CCA, and sets up the numbers of the recipient substations on series of switches COF, of which only one is shown. For each switch COF there is a ring of contacts round the dial CCA which may be connected by means of manually operated contacts CLS with corresponding contacts of a step-by-step switch DD which is stepped at the predetermined intervals by a relay RDD controlled by a clock CPE and the switch MAH. The subscriber arranges the contacts CLS to correspond to his scheme of recipient substations and times, and closes a switch MAS to transfer wires 11, 12 from the subscriber's ordinary line ab to an auxiliary line albl. The lamp LMAH then goes out. In the event of a subsequent incoming call on the line ab, a relay RDE is energized and brings up a relay RM3 which applies battery for 3 minutes to a wire 40 under the control of a clockwork. RDE also connects the rings of contacts round the dial CCA with a wire 79 over leads 36, 37, 38. One of these leads is fed from the switch DD over the contact CLS corresponding to the time of the call and energizes relays RTR and RSA, which both lock. A relay RTK follows RSA and completes a circuit containing a current source S and a motor MO which drives a rotary contact CTO, a cam CMO, and a drum TCH comprising ten contact wheels, each making contact for a different fraction of a turn. At each rotation the contact CTO energizes and releases a relay RDG which advances a distributer DG-DF by one step. In the first off-normal position Y, a relay RF opens the line circuit and in the subsequent positions I to IX a relay RCH removes a shunt from two contacts 1, 2 for various times depending upon the operative contact wheels of the drum TCH and hence upon the number prepared on the operative switch COF. During those times the cam CMO sends impulses corresponding to the prepared number over contacts 1, 2 into the line a<SP>1</SP>b<SP>1</SP>, thereby in effect dialling the predetermined recipient substation. In position XIII of the distributer DG-DF a relay ROC is energized over wiper DG1 and releases the relay RTR, stopping the motor MO and disconnecting the rotary contact CTO. The relay RDG energizes over wiper DG4 and by self-interruption steps the distributer DG-DF to its normal position Z. A relay RSL then operates over wiper DG2 and connects the two lines ab, a<SP>1</SP>b<SP>1</SP>. The call can then continue normally. After 3 minutes the clockwork releases relay RM3 and removes battery from the wire 40, releasing the relay RSA followed by the rest of the equipment. The auxiliary line a<SP>1</SP>b<SP>1</SP> may be borrowed from a neighbour, in which case a meter T is provided for recording only the diverted calls. An absent subscriber is enabled to communicate with his home by means of a microphone connected across terminals MM and a loudspeaker on terminals 72, 73 with an amplifier AH. Before leaving he closes a switch MAC and connects contacts CLS<SP>1</SP> for the required time to an inner ring 27 of contacts round the dial CCA. At the predetermined time he calls his own station, operating relays RDE, RM3, RSA and RTK to close the line circuit. The microphone and loud-speaker are then in operation. The connection is released after 3 minutes as before.