| 摘要 |
<p>1,267,001. Fluid pressure brakes; valves. WESTINGHOUSE BRAKE & SIGNAL CO. Ltd. 19 Nov., 1970 [16 Jan., 1970], No. 2248/70. Headings F2F and F2V. A fluid control valve assembly for a brake system, e.g. for controlling a spring-applied, air pressure-released parking brake has a selflapping valve 2, with a double-ended closure element 3a engaging an inlet seat 5 or an exhaust seat 7, the output being determined by the position of a member 32 urged by a spring 34 into a predetermined position, the spring being inhibited from moving the member only so long as supply pressure is present at the valve. In the "Park" position shown inter-engaged face-cams 37, 38 cause a rod 25 to lift a piston 20 through a spring 22 against the force of fluid pressure in a chamber 26 connected to inlet port 8 by a conduit 28. A piston 11 is caused by a spring 19 to follow and lift the exhaust valve seat 7 clear of the element 3 and put the outlet port 17 into communication with exhaust port 14, thus putting port 17 at atmospheric pressure and allowing the spring actuator to apply the brakes. Failure of pressure at the inlet port 8 allows the spring 34 to move member 32 back to the "Park" position from any other position by release of cams 37, 38 and movement of rod 25.</p> |
