GB1025252A - Fluid flow control valve for braking systems - Google Patents

Abstract

1,025,252. Fluid-pressure brakes; valves. BENDIX-WESTINGHOUSE AUTOMOTIVE AIR BRAKE CO. March 18, 1964 [March 21, 1963], No. 11502/64. Headings F2F and F2V. A dual circuit brake valve for a vehicle pneumatic braking system, particularly a compressed air system, comprises upper and lower valve sleeves 32, 94, respectively, each slidable in a housing 10 having a central partition 20 and including an inlet exhaust valve element 28, 90, respectively, co-operating with valve seats 26, 116, respectively, to normally maintain inlets 12, 16 isolated from delivery chambers 24, 82 leading to respective delivery outlets 14, 18 for the respective brake circuits, an exhaust plunger 48 having a hollow interior 50 being slidable within the sleeve 32 and having integrally formed thereon a relay piston 84, a skirt 88 of which operates the lower sleeve 94 when pressure rises in the chamber 24, and an operating piston 58 having a skirt 56 which encloses and guides an upward extension 54 of the exhaust plunger 48. The chambers 24 and 82 normally communicate with atmosphere through lateral openings 52 in the extension 54, the interior 50 of plunger 48, the interior 96 of the sleeve 94 and an apertured plate 103 equipped with a dust flap 106. When manual effort is applied to a disc 66 it compresses a rubber spring 74 which moves piston 58 to first contact the top of the extension 54, then by its skirt end 64 contact valve element 28 to close off the upper exhaust connection, then move element 28 away from seat 26 to admit compressed air to chamber 24. The clearance between skirt 88 and lower valve element 90 being sufficient to prevent operation of the latter. As pressure builds up in chamber 24 it acts via passage 86 in the partition 20 on relay piston 84 to cause plunger 48 to operate the lower valve similarly, the valves being subsequently lapped by the rising pressure in chambers 24, 82 acting on pistons 58, 84, respectively.