GB174559A - Improvements in train control mechanism for use on railways and the like - Google Patents

Abstract

174,559. National Safety Appliance Co., (Assignees of Folker, H. S.). Jan. 22, 1921, [Convention date]. Fluid-pressure. - Apparatus, in which the brakes are applied when magnetic means carried on the vehicle are influenced by magnets placed on the track, is constructed for control of vacuum brake systems. Similar apparatus for use with pressure brake systems is described in Specification 170,814. The brake pipe is opened by a pneumatic stop valve, which is opened by atmospheric pressure when a vacuum pipe is opened by a duplex valve carried below the locomotive or tender and normally maintained closed by the action of permanent magnets, the effective field of which is weakened on passing over an active permanent magnet fixed on the track. Two valves controlled by permanent magnets, the poles of which are reversely situated, are used on the train in order that one of these valves may always be released by the weakening of the magnetic force on the armature independently of the polarity of the track magnet, or by the weakening of one of the control magnets in relation to the other. Each track magnet has associated with it an electromagnet, controlled automatically by track-circuits, which neutralize the track permanent magnet under line-clear conditions. The arrangement of control magnets, and their coacting pole-pieces and inductor plates is similar to that described in Specification 170,814, the passages controlled by the valve being modified for control of a vacuum system. Fig. 1 shows the control valve F and the stop valve D and the manually operated releasing valve 302. The control valves connected to the armature 45 of each duplex magnet M, M<1> are double-seated valves serving, when the armature is raised, to connect conduits 131, 132 in the valve cap 70 and shut off these conduits from atmospheric pressure in the housing 22. When the armature is released, the flange 54 closes conduit 132 and atmosphere is admitted to conduit 131 through a side port in the valve seating. A ball valve 150 closes the connection to the other valve and conduit 132, which is connected by pipe 128 through a restricted passage 128<1> and the releasing valve 302 to the vacuum chamber. Air is thus admitted to the pipe 130 and the chamber C of the stop valve D. This valve includes a diaphragm 209 attached to the valve 203 which seats on. the flanged seating to' close chamber A from chamber B which is open by ports e to atmosphere. Air in the chamber C raises the valve and admits air from chamber B to the brake pipe T. To reset the duplex-valve, the releasing-valve 302 is turned to shut the pipe 118 and to connect the conduit 132 to atmosphere. The control valve being then subjected to equal pressure above and below, the magnet is able to lift it, and when the valve 302 is replaced the chamber C is exhausted and the valve 203 closes the train-pipe.