Patent GB-980707-A (GB)
Title: Automatic vehicle operation system
IPC: B61L23/00
Filed: 1962-02-20
Abstract: 980,707. Automatic train control systems. WESTINGHOUSE AIR BRAKE CO. Feb. 20, 1962 [Feb. 20, 1961], No. 6467/62. Heading B7N. In an automatic train control system for controlling the movement of trains over a stretch of track divided into blocks TS1-TS5 and a stopping block TS6 by locations LOC1- LOC6, and particularly for a monorail system as shown, the trains are controlled by signalling tones picked up on the train from block conductors BC1-BC6 which extend through the blocks adjacent the tracks. The apparatus at each location TT1-TT6 is supplied from a carrier frequency source CT via a line RFC and includes means for modulating the source signals with signal tones before applying it to the associated block conductor. The apparatus includes at each block junction, e.g. junction TT3, a coil 3LI which co-operates with a coil, e.g. coil V2L3F, at the front part of a train to momentarily operate relay F3 when a train enters the block and a coil 3L2 which cooperates with a coil, e.g. V2L3R, at the rear of the train to momentarily operate relay R3 when the train leaves the previous block. These relays co-operate with their repeater relays FP3, RP3 to release a normally energized stick relay TS3R, which release indicates the presence of a train in the block, and to re-energize the stick relay in the preceding block via line TS2C. The apparatus at locations TT1-TT4 can modulate the carrier signal with one of two tones, a first tone which signals a train speed of 10 m.p.h. and a second which signals 25 m.p.h., in the absence of a modulating tone the train is controlled to stop. The tones are applied in accordance with the occupied or unoccupied state of the ahead blocks, if the next, the next but one, and the next but two blocks are occupied the train is controlled, respectively, to stop, 10 m.p.h. and 25 m.p.h. In block TS5, the block preceding the stopping block TS6, the train can only be controlled to stop or 10 m.p.h. In block TS6, the circuit of an additional slow to energize relay TCR is completed when a train enters the block. Due, however, to the slow to energize characteristic the output of the modulator is applied via a back control of the relay to a line DOC which extends parallel to the station platform, hence a train entering the block receives no signal from block line BC6 and is controlled to stop. The parameters of the section are such that a brake application on entry brings the train to a stop at the station platform. The released state of relay TER also energizes tone generator 3 which modulates the carrier signal and signals the train to open its doors. When the delay time expires relay TER picks up, tone 3 is switched off so that the train doors close and line BC6 is energized with either the 10 m.p.h. or the 25 m.p.h. tones in dependence on the state of the following blocks and the train moves out of the station.  The train equipment includes a carrier frequency receiver CR, three selective circuits Tone 1-Tone 3 which energize relays LSR, HSR and DOR respectively on receipt of their respective tones, a brake application device BVM which is de-energized to apply the brakes when neither speed tone is received, engine control relays T1, T2 which pick up on receipt of Tone 1 (10 m.p.h.) and Tone 2 (25 m.p.h.), respectively, to control the train engine to these speeds and a door-operating mechanism DOM controlled by relay DOR.