GB1354385A - Telescopic hydraulic shock absorbers - Google Patents

Abstract

1354385 Telescopic shock absorbers ARMSTRONG PATENTS CO Ltd 16 Nov 1972 [16 Nov 1971] 53059/71 Heading F2S A telescopic hydraulic shock absorber of the uni-directional flow type comprises a pressure cylinder 12 coaxial within a cylinder 10 with the annular space 14 constituting an hydraulic reservoir, a piston 16 provided with a valve 28 to permit flow through the piston from the pressure cylinder space in front of the piston to the space behind it, a piston-rod guide 20 closing and locating the one end of the cylinders and having two ports 44 to communicate with the space behind the piston, two adjustable valves 52, 72 accessible externally of the outer cylinder controlling fluid flow through the respective ports from the last mentioned cylinder space into the reservoir and a valve block 22 closing and locating said cylinders relative to one another at their opposite ends and provided with valve means 38 for permitting fluid flow from the reservoir into the cylinder space in front of the piston. The valve 52 can be rotated by a screw-driver to bring one of two ports 54, 56 (of different diameters) into operation to connect one of the ports 44 through a tube 46 and the valve to the reservoir. The pressure-responsive valve 72 is also adjusted by a screw-driver to increase or decrease the loading of a spring 74 on the valve to determine the rebound damping characteristic. It acts as a fine adjustment to the valve 52. If the screw 68 of the valve 72 cannot compress the spring 74 completely, the valve can act as a safety valve. The valve adjustment may be made through a mechanical or electro-mechanical drive.