GB407382A - Improvements in or relating to automatic train control systems - Google Patents

Abstract

407,382. Track apparatus for automatic train control. HUDD, A. E., 20, Surbiton Court, Surbiton, Surrey. Aug. 16, 1932, No. 23005. [Class 105.] Automatic train control apparatus comprises a permanent magnet longitudinally disposed along the track and rendered ineffective, under clear signal conditions, by electromagnetic or mechanically operated means which divert the flux away from a train-carried receiver comprising two flux-collecting plates arranged longitudinally so as to be successively energized by both poles of the track magnet, under caution conditions, whereby an armature is moved to effect a warning and braking. Figs. 2 and 3 show in sectional elevation and end view the permanent magnet 10 supported by non-magnetic spacing members 21 in soft-iron cradles 20 attached to the cores 19 of the neutralizing electromagnets 18 ; the assembly is secured by non-magnetic bolts 24 and is mounted on a non-magnetic cast iron base 23. In the arrangement shown in Fig. 6. a magnetic shield 26 carried by arms 27 on an axle 28 is interposed between the train receiver and the permanent magnet 10 by a connection to lever 31 when the signal is cleared. The axle is counterbalanced by a weight 32 and the whole device is enclosed in an aluminium casing. When the track permanent magnet is effective the flux collecting plates 34 of the train-carried receiver, Figs. 9 and 10, direct the flux to polepieces 36 whereby an armature is attracted and removes its turned up spacing lip 40 from between two detent levers 41 which then release a spring-urged plunger 50 in the hollow stem 47 of the brake-pipe venting valve 46 and so permit the valve to open to give an audible signal and a partial brake application. Re-setting is effected by a cable connection 56 which lifts a rod 54 having a lateral member 67 to raise the spring-urged plunger 50 into the position in which it is retained by the detent levers 41 which are then again spaced by the armature lip 40. The rod 54 is recessed at 60 to accommodate in its normal unoperated state one end of a bell crank lever 59, the other end of which actuates the valve stem 47 ; if therefore the rod 54 is wilfully held up the valve 46 remains open. At a danger point, as distinct from a caution point, two longitudinal track permanent magnets are arranged on opposite sides of the centre line of the track and if each is effective two valves are opened thereby giving a full brake application.