Patent ID: 6044940
Filing Date: 2000-04-04
Classification: F16F

Abstract:
Hydropneumatic shock absorber for vehicles comprising:a sliding tube sealed at one end, said one end being provided with an attachment for one of two parts of the vehicle which needs cushioning;a stem presenting at a first end another attachment for the other of said two parts of the vehicle and at a second end a piston engaged within said sliding tube to make a sliding side seal with said tube, said piston being equipped with valve means controlling the flow of a liquid between a first pressure chamber and a second pressure chamber formed within said sliding tube by the opposed faces of said piston, the first pressure chamber being traversed by said stem, said first and second pressure chambers being filled with said liquid to ensure proper braking to the shock absorber during compression and expansion phases;a floating piston within said second chamber to make a sliding side seal to keep said second chamber apart from a compensating chamber filled with gas, wherein the stem is provided with a longitudinal duct or cavity, said cavity communicating through radial ports with said first chamber and through a sized end hole with the second chamber with which a tip of a needle of a variable throttle cooperates, the other end of said throttle presenting a thickened head engaged within a portion of said duct of said stem to make a sliding seal, said duct being filled with liquid and connected, through an external tube with a remote control having a pressure chamber also filled with liquid, said pressure chamber being of a hydraulic cylinder and piston type having a remote piston;wherein the longitudinal cavity of the stem terminates at the end lodging the piston by two consecutive enlarged portions of different diameters increasing towards the thickened head of the needle of the variable throttle engaged within the smaller diameter portion to make a sliding side seal with said other portion, while inside the other portion there is fastened a bushing whose inner cavity forms the sized end hole which cooperates with the tip of the needle of the throttle, while the part of said enlarged portion which is free of the bushing is connected through radial bores with the first pressure chamber of the shock absorber;whereby it is possible by axial displacement of the remote piston in said remote control to change the axial position of said needle of the throttle and therefore also the size or gap of the end hole of said throttle in order to modify the shock absorber braking force.