GB466944A - Improvements in or relating to electric signalling systems for railways - Google Patents

Abstract

466,944. Electric signalling systems. SVENSKA AKTIEBOLAGET GASACCUMULATOR. Nov. 11, 1936, No. 30842. Convention date, Nov. 11, 1935. [Class 40 (i)] In a system in which codes are transmitted by the selection of a code wheel on a continuously rotating shaft, the circuit of a selected code relay, which determines the code transmitted, is completed by a cam as the shaft is passing through a zero position and is maintained for the remainder of the revolution of the shaft by a second cam. As shown in the Figure, when one of the keys 43-45 is depressed the corresponding relay 50-52 operates and locks. When the shaft passes its zero position, cam 26 completes a circuit, over contacts of the operated relay 50-52, for one of the code relays 23-25 which, over contacts 20-22 connects the code contact to the outgoing line. The operated code relay locks for the duration of the code transmission over cam 27. Lamps 57-59 indicate the code being sent, which code is repeated until release key 53 is operated. The code relays lock in series with relay 42 the resistance of which is such that only one code relay can remain operated at one time. In the embodiment described, the signals are transmitted by wireless, a lamp 63 indicates that the outgoing circuit is functioning and loudspeaker 11 repeats the signal to the operator.