Ventilanordnung mit einem Steuerventil fuer zwei Druckmittelsysteme

1,112,330. Valves; fluid pressure brakes. WAGNER ELECTRIC CORPORATION. 21 Sept., 1966 [3 Dec., 1965], No. 42099/66. Headings F2F and F2V. A control valve for a pneumatic braking system comprises a first valve 53 controlling the connection of a brake cylinder port 13 to a supply port 8 or exhaust port 45 in response to movement of a piston 55 by a brake pedal engaging a spring 60, in a well-known manner, and an emergency valve 82. Under normal conditions, the valve 82 engages a seat 66 on the housing so that a secondary supply connected to inlet port 17 flows through ports 75 of a piston member 70 and past valve seat 74 to chamber 80 which has an outlet port 21 connected to a spring-loaded piston of the brake cylinder whereby the piston is moved against the spring to disengage from a diaphragm actuated by the first valve 53. If the first supply fails, continued movement of the brake pedal causes piston 55 to engage an abutment 90 of a rod 86 to move the piston member 70 downwards whereby the seat 74 engages the valve 82 and lifts it off the seat 66 thus connecting the port 21 to exhaust 45. The reduction in pressure at the port 21 allows the piston of the brake cylinder to move against the spring to apply the brakes. After the piston 70 has engaged the valve 82, the pressure area subjected to the inlet pressure increases and the valve laps to close the outlet 21 from supply end exhaust. Further movement of the pedal will increase the braking action. Fig. 1 (not shown) illustrates the air circuit in which a compressor (2) supplies a main reservoir (4) which feed reservoirs (10), (18). The reservoir (10) is connected to inlet port 8 and the reservoir (16) is connected to port 17. Port 21 of the valve is connected through a push-pull valve (23) to the brake cylinder (15). The push pull valve may be actuated to vent the line to the cylinder (15) for parking.