Hydropneumatic resilient suspension cylinder

Claim 1

A hydropneumatic resilient suspension cylinder adapted to be arranged between a wheel supporting means and a vehicle body for stabilizing the height of the vehicle body independently of load variations on the vehicle, comprising a cylinder housing, a head for the cylinder housing, a piston slidable in the housing and a level control means within the housing operative independently of the height of the vehicle body above the wheel supporting means for connecting the pressure space of the cylinder housing with either a pressure source or drain, said level control means including a control piston slidable in said head, said head having passages therein communicating with the pressure space, the pressure source and drain with such passages being controlled by said control piston, spring means within the cylinder head operably related to the control piston upon retraction of the piston from the level position to move the control piston to a position in which communication is provided between the pressure space and pressure source via the passages, a tension spring operably connected to the control piston, and an abutment for the tension spring movable by the piston so that upon extension of the piston beyond the level position against the force of the spring means, the control piston is moved to establish a connection between the drain and the pressure space via the passages while in the level position said passages are blocked by the control piston.