GB351071A - Improvements in or relating to train control systems - Google Patents

Abstract

351,071. Track apparatus for stoppingtrains. ASSOCIATED TELEPHONE & TELEGRAPH CO., 1033, West Van Buren Street, and HUDD, A. E., 947, West Van Buren Street, Chicago, U.S.A. March 17, 1930, No. 5680/31. Divided on 351,039. [Class 105.] The apparatus described is the same as that of Specification 351,039 the claims being directed to the control apparatus which acts in conjunction with the stop signal. According to the present invention a train control system comprises two track elements arranged crosswise with respect to each other and with their mid points lying over each other in the mid line of the track, one element always being effective to exert a control influence, and the arrangement is such that if this element only is active it exerts a control to bring about a brake operation but if the second element is also active this exerts a second control which prevents the brake operation. The train apparatus comprises two receiving devices situated crosswise with respect to each other and with their mid points overlying each other in the mid line of the locomotive and the arrangement is such that if one device is operated, the brakes are operated, but if the second device is also operated it prevents the first device having any effect. In the apparatus shown the track elements acting in conjunction with the stop signal S comprise a longitudinal permanent magnet 51 and a transverse electromagnet 52 with their mid points lying over each other in the mid line of the track. The permanent magnet element acts on a pair of longitudinal flux collecting plates 6, 7 and the electromagnet, energized when the stop signal is at clear, acts on a pair of transverse collecting plates 4, 5. An armature 3 normally abuts against polepieces on the plates 4, 5 and is therefore not moved when both pairs of plates are activated. Should, however, the stop signal be at danger the track electromagnet is not active and therefore the track permanent magnet effects movement of the armature which moves a thin metal strip 63 to uncover a venting port 92 in a vacuum pipe system leading to a diaphragm 11 which is therefore released to open a train pipe valve 66 giving a full brake application. The armature 3 can be reset, when the train is at rest to allow access to an acknowledging key APF, by operating the key to connect the vacuum system to the under side of a spring- pressed plunger 8 having a stem to engage the armature ; the acknowledging key APF cannot be held over as a port 14 opens the vacuum system to atmosphere. The collector plates 4 .. 7 are housed in a casing 98 which has its opening to atmosphere 93 in a position to prevent dirt entering the casing.