GB609007A - An improved resilient shock absorber - Google Patents

Abstract

609,007. Hydraulic shock-absorbers; liquid springs. DOWTY EQUIPMENT, Ltd., and ORD, L. R. March 25, 1946, No. 9183. [Class 108 (iii)] A hydraulically damped resilient device comprises a damping chamber 6, a plunger 1 with a damping head 7 which provides damping on both compression and extension strokes, and by which liquid is displaced on the compression stroke through a flow restriction outlet 26, to provide hydraulic damping with resilient compression of liquid entrapped in the chamber 6 at a high rate of plunger travel, a recuperation chamber 17 communicating with the damping chamber through a non- return valve (not shown) which is automatically closed on the compression stroke and opened on the extension stroke. In the construction shown in Fig. 2 a cylinder 14 encloses the damping chamber 6 which is in communication with the recuperator chamber 17 through the ducts 26 at the upper end and the non- return valve at the lower end (not shown) of the shock absorber. The ducts 26 are formed by radial slots in shims 25 positioned between the end of the cylinder wall 14 and a head 5 of the damping chamber 6. In a modified construction, Fig. 1 (not shown), a single leakage port formed in the wall of the cylinder 14 is employed. The plunger 1 passing through low and high-pressure glands 35, 29 carries a damping head 15 having two sets of ports 8, 9 controlled by a ring 13 and a spring-loaded valve 10 respectively. An annular baffle (not shown) in the recuperator chamber prevents emulsification of the damping liquid. Liquid which may escape through the high-pressure gland 29 is returned through passages 32, 34, to the recuperator chamber 17. Operation.-On compression at a normal rate, the non-return valve at the bottom of the damping chamber is closed and liquid displaced by entry of the plunger 1, flows with damping action through the ducts 25. Damping also occurs through the ports 8 in the damping head 15. At a high rate of compression resilient compression of the liquid momentarily occurs in the chambers 6 due to the large restriction caused by the ducts 25. On extension, the damping chamber 6 is replenished from the recuperator chamber 17 by opening of the non-return valve ; the ports 8 in the damping head are closed by the ring 13 but damping takes place through the ports 9.