GB463946A - Improvements relating to fluid pressure braking apparatus - Google Patents

Abstract

463,946. Fluid pressure brakes. KERSHAW, A. G., SIMMONS, A. W., and WESTINGHOUSE BRAKE & SIGNAL CO., Ltd. Oct. 3, 1935, No. 27293. [Class 103 (i)] In a combined fluid-pressure and electricallycontrolled fluid-pressure brake the electrical controller 9 controls communication between the main reservoir and a driver's valve 7, which controls the fluid-pressure brake. The controller 9 is self-lapping and when a brake cylinder pressure corresponding to the position in the range S.E. to which the controller has been moved, is attained, a cylinder 78 connected to the brake cylinders returns the controller to holding position. The controller 9 comprises a pneumatic control attachment 10 which by means of a port connects driver's valve and main reservoir in release and train pipe and an interlock valve 11 in application and holding position. An inertia device 15 controls the electric-fluid-pressure brake according to the vehicle speed. When the brakes are applied electrically the controller 9 is turned to connect contacts 50, 55 and energize application train wire 16 and application valves 12, and to connect main reservoir pipe 1 to the brake cylinders and also to energize holding valves 13 to close the triple valve exhaust. The resultant retardation of the vehicle causes the pendulum 56 of the inertia device to swing, disengage contact 57 and engage contact 62. The contactor 60 is thereupon de-energized so that its contact 68 breaks the circuit of the application valves 12, which closes, and closes a contact to energize the holding train wire 17 and the second coil 41 of the holding valves 13, the first coil 40 being de-energized by the contact 68. If the inertia device moves further it engages contact 63 and disengages contact 62, whereupon contactor 67 will be de-energized and will de-energize the blow down train wire 19 causing the opening of valves 43 to connect the brake cylinders to escape valves 76, which exhaust the brake cylinders to a certain low pressure. Engagement by arm 56 of the contact 63 energises and maintains closed interlock valve 11. If the current supply should fail or contactor 67, 68 or valve 54 should fail to operate valve 11 would be de-energized and the brakes applied by release of air from the train pipe 3. In holding position of controller 9, holding train wire 17 is energized by contacts 50, 53 and coil 41 of holding valve 13 is energized and maintained closed to prevent release of fluid from the brake cylinders. In emergency position of the controller 9, the pneumatic control attachment 10 connects the train pipe 3 to atmosphere so as to produce a pneumatic application also.