Patent GB-898873-A (GB)
Title: Improvements relating to signalling apparatus
IPC: B61L3/22
Filed: 1959-08-22
Abstract: 898,873. Rope railway signalling systems. STANIER, J. F. N. Aug. 22, 1960 [Aug. 22, 1959], No. 28782/59. Class 105. A signalling system for a rope railway or like arrangement comprises a radio receiving aerial which extends along the track from a central and driving point, radio transmitting means on a car of the train for transmission to the aerial, radio receiving means at the control point and relay means coupled to the radio receiver to provide audible and/or visible signals in response to changes in the transmitted signal and to stop or prevent the starting of the train on interruption of the transmitted signal. The outer conductor of a coaxial cable 5, Fig. 2, which extends along the track length acts as the receiving aerial and each train, e.g. A, comprising a man-riding car 1 and other cars 2, carries a transmitter 3 which is operated by key K1 and energized by a battery 6 via a cable connecting all cars in the train. Each train controlled from the control point is allocated a particular transmitter frequency. The receiving equipment at the control point, Fig. 3, comprises a COMMON AMPLIFIER which is connected to the outer conductor of the cable and a number of frequency selective circuits each tuned to a particular train frequency, e.g. the circuit associated with train A which operates at a frequency x comprises a tuned filter x and detector x which provide an output to operate signal relay XA. The train carried transmitters are normally operating and both signal relays are therefore operated. If the guard on train A wishes to stop his train he releases key K1 and cuts off his transmitter, relay XA at the control point therefore releases and energizes relay XB via contact XA2 and operates an alarm signal at its contact XA3. Relay XB locks over its contact XB1, opens the haulage motor control circuit at its contact XB2 whereby all controlled trains are brought to a halt and operates a train identifying light PLP3 at its contact XB3. The trains cannot be restarted until transmission from train A is restored and relay XB is released by the operator at the control point operating switch S2. The train may also be stopped from the trackside by operation of one of a number of keys K2 positioned along the length of the cable 5 and operated by manual pull switches. For this control the cable is supplied from a 15 v. A.C. source at the control point via a D.C. relay ALA, shunted by a condenser C1, in series with an R.F. choke L, and a rectifier MR1 connects the inner and outer conductors of the cable at the cable end remote from the control point. The resulting D.C. current holds relay ALA in its operated state. Operation of a key K2 breaks the cable circuit at its inner conductor, releasing relay ALA whereby a "no volt" control circuit for an oil circuit-breaker O.C.B. in the haulage motor supply is opened at contact ALA1 and a relay ALB, which locks itself over its contact ALB1 and operates an alarm at its contact ALB2, is energized over contact ALA2. The " no volt" circuit is also broken by simultaneous transmission from both trains (contacts XA1 and YA1 open) and by failure of the cable supply or the supply to the receiving equipment. In another arrangement, Figs. 4 and 5 (not shown), the transmitters are modulated to provide a signalling channel superimposed on the arrangement described which operates without disabling the haulage motor circuit.