Patent GB-715992-A (GB)
Title: Improvements relating to automatic train describer systems
IPC: B61L25/04
Filed: 1952-05-30
Abstract: 715,992. Signalling passage and identity of vehicles. WESTINGHOUSE AIR BRAKE CO. May 30, 1952 [June 26, 1951], No. 13784/52. Class 118 (2). [Also in Group XXX] In automatic apparatus for identifying vehicles e.g., buses or trains which pass over a common section of their routes, each vehicle carries an identifying element which, on passing, selectively actuates an inductive reporting device at the entrance end of the section to apply an indication identifying the vehicle to apparatus for storing and displaying the indication therein and on passing, selectively actuates an inductive reporting device at the exit end of the section to cancel such stored indication. The storing apparatus may comprise a plurality of storage units for storing a. plurality of indications in the order in which their associated vehicles enter the section and each indication is cancelled in the same order by the actuation of the reporting device at the exit end by the vehicle identifying element. When the common section of the routes diverges at the exit end into the several routes, the reporting device at the exit end on operation by a passing vehicle identifying element cancels its stored indication and transmits the indication to a station in advance on the route to be travelled by the vehicle. The storing apparatus may automatically effect operation of the route points switchesto establish a route corresponding to the indication of the vehicle and control the signals governing such route. In the example illustrated when a train V equipped with a coupling coil 10 tuned to frequency f1 passes the first reporting device TD1, it couples the transmitting coil 1 to the receiving coil 4 on the opposite side of the track, the coil 4 being connected through a rectifier to a detector relay AD which is momentarily energised as the train passes, e.g. by a circuit such as described in Specification 706,744, [Group XXX]. Relay L2 is normally energised over back contacts b of relays AD, BD, ND, and back contacts c of relays A2, B2, N2, to condition the unit to receive an indication, and this circuit is interrupted by relay AD but relay L2 is still held over its own front contact a. At its front contact a relay AD picks up relay A2 over the back contacts c of relays Al, B1, N1 and front contact b of relay L2 and at its back contact c relay A2 thereupon releases relay L2 and its front contact c picks up relay L1 which provides a stick circuit for itself over its front contact a. At its back contact c relay L1 opens one of the stick circuits of relay A2 and at its front contact b it picks up relay A1 over push-button CNB. Relay A1 locks over its front contact a and at its back contact c it releases relay A2 which at its front contact c releases relay L1 and at its back contact c picks up relay L2 providing that the train has passed on from device TD1 and relay AD has released. At its front contact d relay A1 lights lamp AE to indicate that route ca is the route for the approaching train and at its front contact e it connects positive battery B to wire N to establish that route automatically providing proper traffic conditions prevail, so represented schematically by operation of locking relay LR. Relay N1 when similarly entergised due to an unclassified train, identified by frequency f3 does not complete any route circuit R, but only lights lamp Ne to indicate the approach of an unclassified train. Should relay Al be energised and a second train identified by frequency f2 pass the device TD1 before the first train reaches device TD2 at point c relays BD and B2 will operate and release L2 as in the case of relays AD and A2 but relay L1 will remain released because its pickup circuit is broken at back contact b of relay A1 and the indication for the second train will remain stored on relay B2 in the second storage unit. Relay 12 remains released and prevents reception of a third indication but additional storage units may be added. On passage of the first train (f) past the device TD2, relay CN is momentarily operated and at its back contact c releases relay A1. Since relay B2 is picked up, relay L1 operates over front contact c of that relay and relay B1 picks up over back contact c of relay CN and front contacts b of relays L1 and B2. Relay B2 is released at front contact c of relay B1 followed by relay L1 and relay L2 picks up. The indication for the second train (f2) is now stored in the first storage unit, lamp BE is lighted and wire R is connected over front contact e of relay B1 to battery terminal B to establish the route cb for this train providing proper traffic conditions prevail as indicated schematically by operation of relay LR. On the second train passing the device TD2, relay CN is momentarily picked up and releases relay B1 to extinguish lamp BE and restores the apparatus to the condition prior to the entry of the first train. In a modification the device TD2 is similar to the device TD1 having also relays AD, BD, ND each provided with a back contact c which replaces contact c of relay CN in the holding circuits of relays A1, B1, N1 and which likewise serves to cancel the indication of the approaching train as soon as it passes the device TD2. In addition, this modified device TD2 serves as a transmitter like the device TD1 to transmit the identification of a train passing the device to an advance station on the route established for the train. To this end a relay operated when the signal governing the route is cleared, closes the transmission circuit for the identification signals.