Abstract: A continuously variable single-tube shock absorber operating according to the skyhook principle and having bidirectional control valves comprising a working cylinder, a piston with piston rod which is movable therein, openings cut out in the piston, spring-loaded shock absorber valves, fitted on either side of the piston, in order to shut off the openings until a certain fluid pressure has been reached, exciting chambers fitted on either side of the piston and each bounded by a stationary disc, a piston skirt which can be slid around such a disc, and a spring-loaded shock absorber valve. The exciting chambers are in communication with a bore in which the pressure is controlled by a control mechanism. Bores through which fluid can flow into the exciting chambers are provided in the stationary discs.

Abstract: A twin-tube shock damper has a hollow piston rod (5) which extends towards the top of the working cylinder (1), a baseplate (8) which closes off the working cylinder and a disc (7) which is arranged inside the working cylinder between the piston (4) and the baseplate and has one or more passages (16) and a non-return valve (17) which allows upward flow through the passages, a central tube (10), a connection (11) between the hollow piston rod and the space above the piston, a damping valve (21) which operates in one direction of flow and servo-control means having an excitation chamber (18) and an excitable coil (30). A control valve in the form of a hollow piston (25) movable in a control valve cylinder (22) provided with orifices (24) and a hollow shaft (27) guided in a valve shaft guide (26) provided with orifices (28) are located in the excitation chamber. Both the control valve cylinder and the control valve are pushed by spring means (23, 29) in the direction of the damping valve body (17).

Abstract: The construction of the shock absorber disclosed in DE-A-2945015 is independently adjustable in two directions however, the adjustment only leads to a variation in the pre-spring tensions in a fixed combination of valves. Only the magnitude of the damping forces may be adjusted, however not the characteristic. The construction of the shock absorber according to the present invention provides the possibility to adjust the characteristic.

Abstract: A twin-pipe shock absorber comprises a working cylinder (1), a piston (4) which is movable in the cylinder and has a passage and upstream valve (13, 14, 15), and external pipe (2) which is fitted around the working cylinder having an oil tank (3) formed therebetween, a disc (7) having a passage (16) and an upstream valve (17) positioned near the passage to shut off the working cylinder, a central pipe (10) extending through the piston (4) having its bottom end projecting through the disc (7) so as to produce a shock absorber in which the shock absorption can be adapted very rapidly to the frequency of movement of the unsprung wheel guide part, the damper valve being disposed at the bottom end of the central pipe (10), and a regulation device to regulate the damping exerted by the damper valve depending at least on the frequency which the working cylinder vibrates.

Abstract: A twin-pipe shock absorber comprises a working cylinder (1), a piston (4) which is movable in the cylinder and has a passage and upstream valve (13, 14, 15), an external pipe (2) which is fitted around the working cylinder having an oil tank (3) formed therebetween, a disc (7) having a passage (16) and an upstream valve (17) positioned near the passage to shut off the working cylinder, a central pipe (10) extending through the piston (4) having its bottom end projecting through the disc (7) so as to produce a shock absorber in which the shock absorption can be adapted very rapidly to the frequency of movement of the upsprung wheel guide part, the damper valve being disposed at the bottom end of the central pipe (10), and a regulation device to regulate the damping exerted by the damper valve depending at least on the frequency at which the working cylinder vibrates.

Abstract: An electrically adjustable shock absorber is disclosed which includes a piston-cylinder assembly with a shock absorbing device. An electrically adjustable cylindrical slide is arranged in a tubular extension which is attached to the piston and which affects the shock absorption device by closing off at least one fluid opening provided in the extension wall to the shock absorbing device.

Abstract: A hydraulic telescopic shock absorber filled with a damping medium in which a piston and a piston rod are reciprocatingly arranged. The piston head which divides the cylinder into two portions is provided with a plurality of longitudinally extending and circumferentially spaced passages extending therethrough. The passage openings on the lower surface of the piston head are closed by a ring-shaped resilient valve. A rigid pie-shaped closing member is coaxially and movably mounted about the piston rod on the upper surface of the piston head. The closing member includes a longitudinally extending adjustment tab which engages an adjustment pin which is fixedly mounted to the lower surface of the cylinder cap. The passages are selectively opened or closed by extending the piston rod until the pin engages the tab and thereafter rotating the piston rod to expose the desired number of passages.

Abstract: An arrangement is provided for adjusting the damping force exhibited by a hydraulic shock absorber. Included is a valve near the piston including passages permitting the flow of fluid through openings in the piston. A linkage is provided which is rotatable about the piston rod to close any or all of the passages through the valve and thus regulate the damping force. The position of the linkage is determined by the interaction of the linkage with a stop member and the piston rod. The stop member is an element which may be extended through one end of the cylinder to engage an extension of the linkage to hold it in place while the piston rod bearing the valve is turned to open or close openings in the valve and thus change the damping force the shock absorber can exert. The stop member is adaptable to be retracted from contact with the linkage so that the adjustment will not be disturbed.