GB204635A - Improvements in shock absorbers - Google Patents

Abstract

204,635. Kerr, B. Feb. 5, 1923. Dash-pots.-In a shockabsorber of the dashpot type for vehicles, means are provided wherebv the recoil is cushioned from its commencement to approximately the normal loaded position of the suspension spring and the remaining movements in both directions are left comparatively free. A cylinder 10, Fig. 2, having working therein a piston 17 with spring-controlled valves 27, is provided at its upper part with a bypass comprising a jacket 14 communicating with the interior of the cylinder 10 by apertures 15, 16. On the downward motion of the piston, the fluid, which may be air, passes freely from the lower side of the piston to the upper through valves 2'7 and the by-pass. On the upward movement the valves close and the air above and below is compressed and rarified respectively, so providing a check action for the recoil until the piston reaches the lower end of the by-pass, when the upward motion of the piston ceases to be retarded. At the commencement of the upward movement, the velocity of the piston is comparatively slow owing to the fact that the suspension springs are overcoming the inertia of the vehicle body; the velocity is then increased and subsequently is retarded by the compression until the by-pass is reached. In a modification, the cylinder communicates with a reservoir by means of a tube 37, Fig. 5, and an inwardly opening valve 32 which is closed only when the pressure in the cylinder rises.