GB681961A - Improvements in or relating to shock absorbers - Google Patents

Abstract

681,961. Hydraulic shock-absorbers. MERCIER, J. Jan. 10, 1951 [Jan. 20, 1950], No. 727/51. Class 108 (iii). A shock absorber comprises a bellows 6 (or alternatively a telescopic chamber) forming a liquid reservoir A, a piston 2 defining two chambers B, C in a cylinder 1, a piston rod 3 formed with spaced ports 23 and slidable in contiguous relation over a hollow counter rod 22 which has at least one port 25 communicating with the chamber C. Liquid can thus pass from the reservoir A to the chamber C. A valve 19 (which may alternatively be disposed in the counter rod 22), limits pressure in the cylinder space above the piston. Flow through the port 25 is controlled by a spring- loaded valve 24. In operation, movement in either direction from the central position is substantially undamped since one or other of flap valves 13, 14, carried by the piston, is free to move against the light loading of its respective spring 17 or 18. On the return movement however the respective spring 17, 18 of the valve, which is otherwise free to open, is under compression and applies a loading to the valve which accordingly provides a damping action to the flow of liquid through the piston. The springs 17, 18 may have a variable homothetic elasticity. In a simpler embodiment, Fig. 2 (not shown), flow through the piston is provided solely by a valveless orifice and the valves 19 and 24 are replaced by mere orifices. The bellows 6 is replaced by an extensible rubber sheath secured at its upper end to the head 5 and its lower end to the outer periphery of the lower end of the cylinder 1. Specification 681,416 is referred to.