GB692602A - Improvements relating to pistons of shock-absorbers - Google Patents

Abstract

692,602. Hydraulic dampers. BOURCIER DE CARBON, C.M.L.L. June 7, 1951 [June 13, 1950], No. 13546/51. Class 108 (iii). The piston of a direct-acting hydraulic shockabsorber has two pairs of diametrically-opposed ducts 1, 2 and 3, 4 controlled by respective oneway valves E, F, each valve permitting liquid to enter freely the inlet ends of one pair of ducts and controlling flow from the outlet ends of the other pair of ducts, the valve being formed by a single thin flat disc or a number of superposed discs, which flex under pressure of liquid at the outlet ends of the ducts along diametrically-opposed curves each having rectilinear generators disposed at right-angles to the piston axis. The discs E, F may alternatively be star-shaped, Fig. 2 (not shown), each point or prong of the star controlling flow through a respective port. Other ports opening freely between the prongs are controlled by the correspondingly-shaped lower valve E. In the construction shown in Fig. 3, the piston is cut away at X and Y so as to permit flow from arcuate ports p, q (controlled by a circular disc valve E) to escape without interference from the other valve F. The area of the piston in contact with the valve may be reduced by the provision of grooves milled in the face of the piston, adjacent, but spaced from the surface of the piston. If superposed discs are employed their diameters may progressively decrease in a direction away from the valve seat. Typical dimensions of the ports and disc thicknesses are given. The piston surface may be radially spaced from the wall of its cylinder to provide a laminar damping flow as described in Specification 686,662.