A height adjustment device used on furniture includes an inner tube having multiple clamp portions and multiple contact portions extending from the inner periphery thereof. Multiple grooves are defined in the outer periphery of the inner tube. A pneumatic tube is inserted into the inner tube and clamped by the contact portions. The inner tube is located in an outer tube that has a bottom cap and a top cap. Multiple ridges extend from the inner periphery of the outer tube. Each reduced opening accommodates the ridge corresponding thereto. The pneumatic tube has a piston rod and is connected to the bottom cap of the outer tube. The piston rod drives the inner tube to move relative to the outer tube. Multiple roller units are connected to ridges and roll the grooves of the inner tube to reduce friction between the inner tube and the outer tube.

A damping device includes a housing and a piston. The housing has an inner wall, and a chamber is defined by the inner wall. The chamber has a damping medium filled therewith. The piston is movable in the chamber, wherein the inner wall has a plurality of inner diameters.

A damper device includes a cylinder, a piston, a seal ring member, and a transmitting portion. The piston includes an annular outer circumferential portion, a first stopper portion, a second stopper portion, and a projecting portion. The projecting portion has an inclined surface which is inclined radially outwards form a side of the second stopper portion towards a side of the first stopper portion. The seal ring member is configured to allow a first chamber to communicate with a second chamber when a portion of the seal ring member which is not restricted by the first stopper portion is deformed in a direction away from the second stopper portion due to friction caused between the seal ring member and the cylinder or a fluid pressure from the second chamber to ride on the inclined surface.

An air spring assembly is disclosed. The air spring assembly includes a piston assembly including a piston, at least one compliant member, a seal configured to provide an air tight seal between the piston and a wall of an air chamber, and a fastener configured to couple the piston with a shaft.

A damper device is configured so that a piston moves in a cylinder. A seal ring member is provided to the outer periphery of the piston to device the inside of the cylinder into a first chamber and a second chamber. A transmission member is connected to the piston and can transmit external force to the piston. A cutout section is formed with a predetermined circumferential width in a first stopper surface. A communication section has an opening in an annular outer peripheral section located closer to the second chamber than the cutout section. When the seal ring member is pressed toward the first stopper surface, the seal ring member is deformed so as to partially enter the cutout section.

A fluid-filled piston cylinder unit comprises a housing with a longitudinal axis and with an interior, a piston rod guided out from the housing in a sealing manner, which can be displaced along the longitudinal axis, as well as a piston connected to the piston rod, which divides the interior into a first sub-interior and a second sub-interior. The piston has a first fluid channel and a second fluid channel in each case for a fluid flow between the first sub-interior and the second sub-interior. The piston has a piston valve for closing the first fluid channel, whereby the piston valve in dependence of a fluid pressure opens the first fluid channel.

A gas-filled cylinder, particularly for a damping device with single manifold, the cylinder comprising: a tubular jacket, closed at one end by an annular head portion, a rod with a piston which translates inside the jacket through the head portion, the piston being directed toward the inside of the jacket, the jacket and the piston defining a portion of an expansion/compression chamber for the gas, at least one sealing element between the piston and the internal surface of the jacket. The cylinder has at least one safety hole on the internal surface of the jacket.

A shock absorber includes a first end and a second end that reciprocate relative to one another. The shock absorber includes a gas spring chamber, a damping chamber, and a floating piston. The first side of the floating piston is in fluid communication with the gas spring chamber. The second side of the floating piston is in fluid communication with the damping chamber. The gas in the gas spring chamber applies pressure against the floating piston, which applies pressure to the substantially incompressible fluid in the damping chamber. This pressure transfer may be adequate to minimize or prevent cavitation.

A shock device for an at least partially muscle-powered two-wheeled vehicle, including at least one tube system having two telescopic tubes, the tube system extending from a first end to a second end. A suspension system is provided which is effective between the two ends and which biases the two tubes to an extended position. The suspension system includes a positive air spring and an independent, series-connected supplementary spring. Both the positive air spring and the supplementary spring bias the tube system to the extended position. The supplementary spring shows a lower breakaway force than does the positive air spring, and the ratio of the suspension travel of the positive air spring to the suspension travel of the supplementary spring is higher than 4:1.

A damper includes a piston and a cylinder housing the piston, and generates a braking force based on a movement or relative movement of the piston. The piston includes a trunk portion and a seal ring surrounding the trunk portion. A first seal portion against an inner wall of the cylinder is formed on an outer peripheral portion in the seal ring, and a second seal portion against a circumference wall portion projecting from the trunk portion is formed in a front end portion positioned on a pressure chamber side. Also, a support rib portion is provided outside the trunk portion, which allows the seal ring to move within a predetermined range along a moving direction of the piston in a state wherein a movement gap for a fluid is formed between the trunk portion and an inner peripheral portion of the seal ring.