GB211637A - Improvements in or relating to railway signalling systems - Google Patents

Abstract

211,637. Automatic Telephone Manufacturing Co., Ltd., and Hudd, A. E. Dec. 19, 1922. Electrical systems, aromatic.-In order to provide for the transmission of transient current for the purposes described in Specification 163,418 over long lengths of track while avoiding the need for insulation joints and impedance bonds, there is provided at the positions along the track relaying or re-transmitting apparatus, comprising a relay which is prevented from operating effectively for a predetermined interval after having operated once, and is cut out of circuit while the controlled generator of transient current is transmitting energy to the track rails. The relay 37 responsive to transient alternating currents received over the track and through the transformer 36, has a vibrating armature, broadly tuned, which controls slow acting relays 38, 39 which in turn control the slow acting relay 40, the armature 42 of which, when raised, opens the circuit of transformer 36, which is thus energized only until relay 40 is excited. The armature 50 of relay 40 puts in circuit the vibratory generator 41 which transmits current 'from batteries 51, 52 to the rails. The make-and-break contact 46 of this generator is in the circuit of the relays 38, 39 so that if the relay 37 is energized a second time while the vibrator generator is still in operation, the relays 38, 39 are not energized.