GB436955A - Improvements in or relating to fluid shock absorbers - Google Patents

Abstract

436,955. Shock-absorbers. CARTER, W. A., 12, Treen Avenue, Barnes, London. April 17, 1934, No. 11526. [Class 108 (iii)] A shock-absorber of the rotary vane or reciprocating piston type comprises a fluid-recuperating chamber 5 separated by a partition 11 from the working chamber 3, a vane or piston extension, piston-rod, or separate member 2 being adapted to enter one end of the working chamber from an auxiliary chamber or the recuperating chamber, on movement of the vane or piston 1 in one direction and to withdraw therefrom on opposite movement of the vane or piston, the working, recuperating, and auxiliary chambers, the vane or piston, and the extension, piston-rod, or separate member being all enclosed within the casing of the shock-absorber. The entrance of the extension &c. into the working chamber causes a displacement of fluid additional to that displaced by the vane &c. and therefore an increased fluid resistance to movement of the vane, the additional fluid displaced leaking into the recuperation or auxiliary chambers, for example through valve-controlled passages. The rotary vane shock-absorber shown in Figs. 3, 4 includes also a reservoir 4, the vane having a curved extension 2 passing through the partition 11. The working and recuperating chambers communicate through non-return valves 10. The fluid transfer passages 6 are controlled by a conical valve 7 and a co-operating floating valve-seat C gives differential action. In a modification, the reservoir, valve 7, and valve-seat C are omitted, the fluid passing through a manually-adjustable orifice in the hub of the vane. In another construction, Fig. 9, a curved member 16 secured to the vane 1 acts through a spring 15 on a separate member 2. The member 16 may be dispensed with and the member 2 spring-pressed to follow the movements of the vane. Figs. 18, 19, 20 show a further construction in which the separate member 2 has a sleeve-like extension 33 adjustable from outside the shock-absorber casing which is fixed to an arm 25 rotatable about a fixed pivot 26. A lever 24 is fixed to the extension 33 and mounted between rubber buffers 27, 28, while links 31, 32 are adapted to rotate the vane 1. In operation the fluid resistance to movement of the vane 1 tends at first to maintain the link 31 and arm 25 comparatively rigid with one another so that they rotate together about pivot 26. The lever 24 accordingly moves relatively to the shock-absorber casing and causes the member 2 to follow the movement of the vane, which latter movement occurs as the fluid is forced through the transfer passages and the resistance decreases so that the link 31 moves relatively to the arm 25 about the axis of the shockabsorber. Fig. 5 shows a reciprocating-piston shock-absorber in which a valve 7, slidable in the hollow piston-rod 2 and manually-adjustable by a tapered pin B, Fig. 6, controls fluid flow through the piston passages 6. Fluid can also pass through a hole 8 in the rod 2, along a groove 12 in the valve 7, and through passages 13, 14 adjustable by a pin 9, Fig. 6, back into the recuperating chamber 5. In a modification, a reservoir surrounds the shock - absorber cylinder and the recuperating chamber is arranged above it. Fig. 14 shows a construction in which an auxiliary spring-pressed plunger 21 is slidable with clearance on the rod 2. In operation, during slow movements of the piston 1 entry of the rod 2 into the cylinder 3 displaces fluid through the restricted clearance space between the plunger 21 and rod 2 and freely past valve 9. During quick movements of the piston some fluid passes through the clearance space while the remainder acts on plunger 21 and causes it to force fluid past the valve 9 which in this case restricts the increased flow. In a modification, the plunger 21 slides in a chamber of smaller diameter than the chamber 3. The construction shown in Fig. 17 includes a piston-extension 2 passing into an auxiliary chamber 22, so that on movement of the piston 1 to the left, the entry of the rod 2 into the chamber 3 causes fluid to be forced from the chamber 3 into the chamber 22, for example, through an aperture in the end of the chamber 22. In certain constructions, the vane or piston extension &c. may vary in cross-section through part or the whole of its length and pass with clearance through the aperture in the partition 11 to provide a variable leak-orifice for the fluid. Alternatively, the extension &c. may be of uniform cross-section and the amount of clearance adjusted manually. British Specification 416,392 and U.S.A. Specification 1,821,142 are referred to.