GB487244A - Improvements relating to driver's brake valve devices for fluid pressure braking apparatus - Google Patents

Abstract

487,244. Drivers' valves. KERSHAW, A. G., SIMMONS, A. W., and WESTING- HOUSE BRAKE & SIGNAL CO., Ltd. Dec. 16, 1936, No. 34606. [Class 103 (i)] [Also in Group XXIX] A driver's valve of the self-lapping type for fluid pressure braking apparatus comprising a controlling handle adapted to co-operate with a floating lever to effect the operation of a fluid supply valve and a fluid release valve together with a movable abutment subject to the pressure of a loading spring and of the pressure obtaining in the brake cylinder and arranged to move the supply and release valves to their closed position under brake cylinder pressure has the supply and release valves adapted to be operated by fluid under pressure under the control of auxiliary valves actuated by the floating lever. The spindle 2 adapted to be rotated by a detachable handle carries a cam 4 adapted to co-operate with a roller 5 on the floating lever 6. This lever which is centrally supported by a link 7 turning on a fixed pivot 8 carries at its extremities rollers 37, 38 co-operating with the valve actuating spindles 35, 36, of the auxiliary valves 21, 32. The valve 21 co-operates with a seat on the main release valve which is actuated by a leaky piston 16 working in a cylindrical chamber formed in the spring loaded pistons 13. The valve 32 co-operates with a seat on the main supply valve 27 actuated by a leaky piston. In the release position shown valve 32 is held in the closed position by spring 33 and valve 27 is also held in the closed position by fluid pressure and spring 34. The main and auxiliary release valves are held in the open position by spring 18, 23 respectively. When the spindle is rotated to apply the brakes the floating lever is first turned about the end 25 causing the valves 21, 16 to be applied to their seats thus closing communication between the chamber 1A connected to the brake cylinder and the conduit 12 leading to atmosphere. Continued rotation turns the lever about the end 10 and opens the valve 32 venting the chamber behind the piston 26 and allowing the supply valve to open. As pressure builds up in the chamber 1A the spring loaded piston 13 is pushed back allowing the lever to turn about the roller 5 and permit the closing of the auxiliary and main supply valves. The spindle 2 is extended downwards where it is formed with a lug 41 having a lost motion connection with a rotary disc valve 40. This valve is arranged to be operated by the movement of the handle beyond the service position to the emergency application position to effect the release of fluid from an emergency brake pipe. When the handle is moved in the opposite direction beyond the release position to the " handle off " position the cam is operated to cause a full service application of the brakes and finally the additional valve closes the communication between the main reservoir and the supply valve. Return of the handle to the release position effects, preferably through the intermediary of the additional valve, the recharging of the emergency brake pipe from the main reservoir through the usual reducing valve. A manually operated stop normally prevents the movement of the handle from the release to the " handle off " position.