GB572319A - Improvements in or relating to hydraulic shock absorbers - Google Patents

Abstract

572,319. Hydraulic shock-absorbers. NEWTON, N. B. Oct. 14, 1943, No. 16888. [Class 108 (iii)] A hydraulic shock-absorber comprises a cylinder 10, a piston assembly including a piston-rod 31, piston 32 and piston-rod extension 33, guide means 11 and gland packing means 12a, 12b at one end of the cylinder, a bulkhead 16 forming a guide for the piston-rod extension, a recuperative fluid reservoir 23 beyond the bulkhead and a sleeve 20 spaced around the cylinder, the space 21 forming part of a fluid-return passage from the gland packing to the reservoir. The piston assembly also includes opposed control valves 34, 35, loaded by a common spring 36, and spring-loaded non- return plate valves 37, 38 which together control passages for flow of fluid as indicated by the arrows. The loading of the spring 36 is adjustable by axial movementof the seating 40 which is effected by relative rotation of the piston-rod and its extension as described in Specification 572,235. Excessive pressure on the gland packing 12a by fluid leaking past the guide bush 11 is prevented by the provision of a passage 15 which allows the fluid to pass into the space 21 and through passages 19, 17 to the chamber 23. A plug 25 in the chamber 23 serves both as a filling device and to release excess pressure, being provided with a central release passage normally closed by a spring- loaded valve 26. At the other end of the shock-absorber, the sleeve 20 is screwed internally to receive a ring 28 which, acting against a washer 29 to compress a sealing ring 30 against a rear face of the guide bush 11, operates as a final clamping means in the assembly of the parts 10, 11, 16, 20, 23. A flexible end cover 42 is secured between the ring 28 and a further ring 41 attached to the piston-rod.