GB1048463A - A pneumatic suspension levelling device for vehicles - Google Patents

Abstract

1,048,463. Air suspension valves. FABBRICA ITALIANA MAGNETI MARELLI S.p.A. Feb 6, 1964 [Feb. 7, 1963], No. 5130/64. Heading B7D. A levelling device of an air suspension system comprises a piston 34 which is moved downwards by spring 50 when a pressure air supply to chamber C from inlet 62 is cut off or falls to close the passage between piston flange 52 and seal 54 isolating the outlet 64 to the air springs from the levelling valve which comprises a spring- loaded valve 40 seating in piston 34 and a hollow pushrod 30 responsive to suspension movements through ball 28, rotary cam 14 and arm 18. In operation when the air pressure in chamber C is sufficient to raise piston 34 air is supplied to outlet 64 for levelling when valve 40 is displaced downwardly by pushrod 30 and returns from outlet 64 when cam 14 rotates clockwise and spring 32 raises the hollow pushrod first seating valve 40 and then permitting air to pass through the central passage and bores 72 of the pushrod, the castellated top 74 of piston 34, passages 76 and 78 and a dustguard (Fig. 2, not shown). In an alternative embodiment (Fig. 3, not shown) a piston 34a is pushed down against a spring 100 when the inlet air pressure is sufficient opening a passage between seal 104 and annular ridge 102 of the piston and thus connecting the passage 70a leading to the air springs with the levelling valve which includes valve 40a, check valve 94 and pushrod 30a.