Shock absorber with load compensation

In a shock absorber device for an automotive vehicle of the type comprising a cylinder containing a hydraulic fluid;

• a piston located in and dividing said cylinder into a first chamber and a second chamber;
• a rod connected to said piston and extending through said second chamber for actuating said piston in said cylinder;
• means defining a hydraulic fluid reservoir;
• flow restriction means providing fluid communication between said hydraulic fluid reservoir and said first chamber and causing the pressure in the first chamber to increase in response to piston movement toward the first chamber;
• a spring biased control valve on said piston, said control valve being movable during rapid compression movement of said piston from a closed position to an open position at which said first chamber is in communication with said second chamber, said control valve having surfaces exposed to pressures of the fluid in the first and second chambers;
• a substantially fluid tight reference chamber on said piston containing a substantially constant pressure gas for biasing the control valve toward its closed position;
• said control valve and said reference chamber acting as pressure control means operable to provide damping forces which decrease progressively when the compression rate increases;
• an elastic member for fastening said damping device to a part of the vehicle, said elastic member having a first portion defining an end of said first chamber and a second portion outside of said first chamber whereby the pressure of the hydraulic fluid increases to open said control valve in case of a rapid compression stroke;
• means providing an external casing integrally connected with said rod and sealingly enclosing said cylinder for sliding movements of said cylinder within said casing;
• and,
• means for subjecting said external casing, said reference chamber and said fluid reservoir to the same gas pressure of an external source of variable pressure gas so a pressure variation in said external casing results in a corresponding pressure variation in said first chamber during rapid compression movement of the shock absorber, acting on said first portion of the elastic member, such that said elastic member is deformed depending on the ratio between the cross section of the cylinder and the cross section of the first portion of the elastic member.

A shock absorber device for an automotive vehicle comprising an outer envelope containing a hydraulic fluid;

• a cylinder mounted within said outer envelope and communication therewith;
• a piston defining within said cylinder a first chamber and a second chamber;
• a rod connected to said piston and extending through said second chamber for actuating said piston;
• means defining a hydraulic fluid reservoir;
• flow restriction means providing fluid communication between said hydraulic fluid reservoir and said first chamber;
• a spring biased control valve coupling said first and second chambers;
• means defining a reference chamber containing a gas, including a movable wall member integrally connected to said control valve such that movement of said wall member causes a corresponding opening of said control valve in response to a rapid compression movement of the shock absorber;
• means defining an elastic member so mounted within said envelope as to transmit the damping forces to said envelope, said elastic member comprising a first portion defining a limit surface of said envelope and subjected to the pressure in said envelope and a second portion outside of said envelope;
• means providing an external casing integrally connected with said rod and sealingly enclosing said envelope for sliding movements within said casing;
• and,
• means for communicating said external casing, said reference chamber and said fluid reservoir with a common source of variable pressure gas so a pressure variation in said external casing results in a corresponding pressure variation in said envelope during rapid compression movement of the shock absorber, acting on said first portion of the elastic member, such that said elastic member is deformed depending on the ratio between the cross section of the cylinder and the cross section of the first portion of the elastic member.