GB493657A - Improvements in resilient struts for use more especially in connection with tanks and the like - Google Patents

Abstract

493,657. Shock - absorbers. RIBBESFORD CO., Ltd., and THORNHILL, P. W. July 16, 1937, No. 19773. [Class 108 (iii)] An oleo-pneumatic shock - absorbing strut comprises a pair of cylindrical members 10, 11 arranged longitudinally side by' side, preferably concentrically, one cylinder 10 being substantially completely filled with liquid and the other cylinder 11 containing gas for resilience, while a plunger 18 fitted with a damping head or piston 19 works in the liquid chamber and also acts directly to compress the gas in the other chamber. In the construction shown the cylinders 10, 11 are arranged concentrically, and the inner cylinder 11 is fitted with a floating piston 17 which separates the liquid in the cylinder 10 and part 15a of the cylinder 11 from air contained in the remainder of the cylinder 11 and in the end portion 28 of the plunger 18. The spaces 10, 15a communicate by apertures 16, and the damping head 19 is provided with a number of passages, the combined area of which is greater than the total area of the apertures 16, but through which in one direction of movement of the head 19 the flow is restricted by an annular flutter valve 23 having only a few relatively small passages 25. During an inward movement of the plunger 18, liquid is displaced in the cylinder 10 from one side of the head 19 to the other substantially freely and, except under very sudden shocks, no liquid is forced into the space 15a except the amount displaced by the entrance of the wall of the cylinder 18. The return movement is damped by the action of the valve 23. Leakage of liquid is prevented by rubber packing elements disposed on the pistons 17, 19 and at the various joints.