GB356100A - - Google Patents

Abstract

356,100. Automatic exchange systems. SIEMENS & HALSKE AKT.-GES., Siemensstadt, Berlin. March 21, 1930, No. 9132. Convention date, April 11, 1929. [Class 40 (iv).] Telegraph connections are set up over existing telephone lines leading from subscribers to their exchanges by means of numerical selectors at the telephone exchange. The line may be extended to a telegraph line or to an automatic telegraph exchange. If the subscriber FA, Fig. 1, wishes to select the telegraph line TA, he removes his receiver and dials the particular number of the line TA, thereby setting the selector LW on terminals connected to a relay U, which switches the line a, b through to the relay N. The subscriber then presses key ET, energizing relay B and closing a circuit from the sub-station battery B<1> for the relay N, which causes relay R1 to energize relay C thereby causing the rotary magnet DAS1 to rotate the line finder AS1 until the calling line is found. Relays P, T, A, V energize in the usual way, relay A extending the line to the telegraph apparatus and relay T closing a fresh circuit for the relay U. To release the connection, the subscriber replaces key ET and depresses key AT, thereby de-energizing relays B, N, &c. To call a particular line from the telegraph station the corresponding key RT is depressed, thereby causing a free line finder to extend the telegraph line TA to the line a, b, say, as described above, the switch ar1, ar2 being then moved to send current of a frequency to which the relay R is tuned, thereby causing relay B to extend the line a, b to the telegraph receiving apparatus ER. In the arrangement shown in Figs. 2, 2a a combined telephone and telegraph subscriber may obtain a telegraph or a telephone connection to a combined subscriber of another telephone exchange, by dialling different numbers according to whether a telephone or a telegraph connection is desired. To obtain a telegraph connection, the completion of the preliminary dialling operates a relay U at the telephone exchange (FV1, Fig. 2a) which switches the line through to the selector devices of a telegraph exchange TV from which the line is extended to a combined subscriber F/T of the telephone exchange FV2 on the completion of dialling impulses which effect the operation of the U relay allocated to the desired subscriber at the exchange FV2. The transmission of the messages in the two directions is effected by relays Er, Es, operating contacts er, es and within the telegraph exchange is carried over two pairs of double lines as described in principle in Specification 306,406, [Class 40 (iii), Telegraphs, Electric]. A telephone conversation between subscribers of the exchanges FV1, FV2 is carried on over the line VL connecting the two telephone exchanges.