Patent GB-672983-A (GB)
Title: Improvements relating to a telephone set with a device for composing call-signs
IPC: H04M1/272
Filed: 1949-06-13
Abstract: 672,983. Automatic exchange systems. KAELIN, P. June 13, 1949 [June 14, 1948], No. 15644/49. Class 40 (iv). A substation is provided with means for registering the number of a wanted subscriber and repeatedly transmitting the dialling impulses corresponding to this number until the call is successful. Registering wanted number, say 136. The substation has ten numbered keys MAN1 ... MAN0. The subscriber depresses the key MAN1, causing a relay RR to advance a switch CRR by one step and to energize a relay RTR which locks, lighting a lamp LMAA and bringing up a relay RA. The switch CRR in position I feeds a group of ten storage relays PR<SP>I</SP>1 ... PRIO, of which one, PR<SP>I</SP>1, selected by the key MAN1, operates and locks over a wire 21. The subscriber releases the key MAN1 and depresses the key MAN3. The switch CRR now advances a second step to position II, where it feeds a second group of storage relays PR<SP>II</SP>1 ... PR<SP>II</SP>0 (not shown), of which PR<SP>II</SP>3 operates and locks, having been selected by the key MAN3. Similarly the subsequent depression of the key MAN6 causes the operation of a relay PRm6. The wanted number 136 is now stored in the relays PR. The keys MAN may be replaced by a dial. Outgoing call. To call the stored number the subscriber presses a key MTK, lighting a lamp LMTK and energizing a relay RTK which closes the line circuit 10, puts an alternating current source S in circuit with an amplifier AH and a motor MO, and releases the relay RA, thereby returning the switch CRR to normal. The motor MO drives a rotary contact CTO which at each revolution momentarily energizes a relay RDG to advance a distributer DG by one step. In its first off-normal position Y, the distributer arm DG2 feeds a relay RF which opens the line circuit 10. In the subsequent positions I to XII, the distributer arms DG2, DG1 feed, through the contacts of the operated storage relays PR and the corresponding contact wheels of a drum TCH driven by the motor MO, a relay RCH which removes a shunt from contacts 1, 2 for various times depending upon the selected contact wheels. During these times a cam CMO driven by the motor MO transmits impulses corresponding to the stored number over the line ab, while indicator lamps LMAN are lit. In positions XIII to XVIII, the distributer arm DG3 completes a circuit for a loudspeaker connected to terminals 72, 73. If the called line is engaged, the caller hears busy tone on the loudspeaker and the call is repeated until the called line becomes free, whereupon the caller hears ringing tone or an answer and presses a button MAA. This releases the relay RTR, stopping the motor MO and switching battery from the rotary contact CTO to the distrivuter arm DG4 over which the relay RDG by selfinterruption drives the distributer DG to its normal position Z. The conversation takes place over the loudspeaker and a microphone or by means of the usual handset lifted from a cradle F to disconnect the loud-speaker. The depression of the button MAA may be replaced by the operation of a relay ROC when the called party lifts his receiver or by other similar relay means. The button MAA may also be used to cancel a wrong number during the registering process. To avoid delays while the amplifier AH warms up, it may be kept in circuit by a switch MACH having an indicating-lamp LMACH. Incoming call; automatic answering device. On receiving a call, the subscriber presses the key MTK to operate the relay RTK and close the line circuit 10, or he may have previously brought into use an automatic answering device by closing a switch MAR, thereby lighting a lamp LMAR. The incoming call then operates a relay RDE which brings up a relay RSA to energize the relay RTK. The line circuit is then closed and the microphone and loudspeaker are in operation, so that the subscriber may engage in a conversation. At the end of the conversation, he releases the key MAR. The relays RSA, RTK restore and the subscriber may close the key MAR again in readiness for any subsequent incoming call. Modified system. The storage relays PR and switch CRR may be replaced by adjustable cams CA, Fig. 4, arranged in grooves I, II, III, &c. on a cylinder TE which rotates stepwise under the control of a relay STE. The cams CA are selectively set by relays RCA controlled by the keys MAN and operate contacts CTE feeding the contact wheels of the drum TCH. The relays STE, RCA may be replaced by mechanical transmission members. Registering two numbers for two successive calls. This is achieved by setting up the first number on the keys MAN as before, closing a switch MAD, and then setting up the second number. The switch MAD lights one of two lamps DU, PL and brings up the relay RR which by self-interruption steps the switch CRR until it reaches its position VI where it operates a relay RDU to disconnect the relay RR. The switch CRR therefore stops in position VI and the storage of the second number then begins in position VII and the group of relays PR<SP>VII</SP>. The subscriber presses the key MTK and the first number is called as before. If it is busy, the distributer DG continues its travel and, in position Y, the arm DG3 causes a relay RDD to advance a switch DD through one step. The wiper DD1 is now connected to the distributer arm DG1 instead of DG2 and the second stored number is called. This process continues while the lamps DU, PL light alternately according to which number is being called, the signals such as busy tone being heard on the loudspeaker. When one line is found free, the caller presses the button MAA and converses. The distributer DG goes home and the relays PR release, except those storing the number not yet obtained, which are held over a wiper DD2 and wire 20 or 21. At the end of the conversation, the caller opens the switch MAD to extinguish the lamps DU, PL and transfer battery from the distributer arm DG3 to a wiper DD4 over which the relay RDD drives home the switch DD. A wiper DD3 passes over a contact XXV and operates the relay RTR to start the calling of the second stored number. Frequently-wanted numbers may be kept set up on series of switches COF. To call one of them, the subscriber presses a corresponding button, say MAF1, which lights a lamp LMF1, feeds an arm DF1 of the distributer DG, operates the relay RTK, starts the motor MO, and feeds the rotary contact CTO which causes the relay RDG to drive .the distributer DG. In its first off-normal position Y, the distributer arm DF1 extinguishes the lamp LMF1 and brings up the relay RTR to take over the feeding of the motor MO. The distributer arm DF1 continues its travel and the registered number is called by means of the drum TCH as before, under the control of the switches COF over wires M1 to MO. The subscriber may register a number during a telephone conversation by operating the keys MAN as before. The relay RTR operates and momentarily energizes a relay RBL, which holds since the relay RTK is already operated and prevents the motor MO from starting and the relay RA from releasing. At the end of the conversation, the subscriber releases the key MTK, restoring the relays RTK, RBL, and he may call the registered number by once more pressing the key MTK. The apparatus may be provided with a timing device, such as a luminous clock, and means for recording, on paper tape for example, the stored numbers and other information. Reference has been directed by the Comptroller to Specification 672,689.