GB895433A - Improvements relating to vehicle air springs - Google Patents

Abstract

895,433. Road vehicle levelling valves. WESTINGHOUSE BRAKE & SIGNAL CO. Ltd. Nov. 11, 1960 [Nov. 11, 1959], No. 38214/59. Class 108(2). A levelling valve for vehicle air springs comprises an open-ended hollow stem 32 giving access to a release or exhaust path 34, which is movable axially by an operating arm 24 to engage sealingly at its open end and unseat an admission valve member 42/46 biased to seat on a barrel 38 and in which the barrel and stem are relatively adjustable so that for a given position of the operating arm 24 the valve can be preset in the lapped position. In the embodiment a casing 10 houses the barrel 38, slidable stem member 26 and in a crossbore the cam body 20 which is rotated by the attached operating lever 24 and has a cam portion 22 which imparts axial movement to the stem member 26 against the bias of spring 36. In operation when stem member 26 moves left the hollow stem 32 seals against and then lifts primary admission valve 42 off seat 40 in the barrel when air from inlet 70 flows through the hole in secondary valve 46 until on further movement of the stem valve 42 lifts valve 46 off seat 48, allowing an increased air flow into casing 10. When the stem returns to the right, valves 46 and 42 seat on the barrel and then the casing 10 is connected through the stem with exhaust path 34. To preset the valve the arm 24 is fixed relative to the casing 10 as with a dowel 64 locating in holes in the arm and lug 59 provided on the casing and the barrel 38 is screwed in or out of the casing 10 until the valve is lapped. The barrel is then locked in position with locknut 68.