A damping device includes a housing, a piston and a controller. The housing defines a chamber filled with a damping medium. The piston is movable in the chamber and includes a passage for allowing the damping medium to pass through. The controller includes a control member and a resilient member. The control member is capable of being moved toward the passage of the piston or closing a portion or all portions of the passage of the piston in response to a speed of the piston.

A damper providing varying damping force is provided. The damper may include a housing and a rotary member rotatably received the housing. The rotary member may rotate within the housing between defined end points of travel to define an angular range of travel of the rotary member. An outermost surface of the rotary member may be spaced inwardly from an inner surface of the housing defined between the end points of travel to define a gap between the outermost surface of the rotary member and the inner surface of the housing throughout the angular range of travel. The gap may vary in dimension depending on a rotational position of the rotary member to provide varying damping rates within the angular range of travel of the rotary member.

A piston-cylinder unit has a piston rod at which is arranged at least one piston which has at an outer lateral surface a radially elastic piston ring that moves into a cylinder depending on a stroke position of the piston rod and has a smaller diameter than in a stroke position in which the piston is located outside of the cylinder. The piston ring has a stop that defines a maximum diameter of the piston ring.

A piston-chamber combination including a chamber (2) which is bounded by an inner chamber wall (4), and including a piston (1) in the chamber (2) to be engagingly movable relative to the chamber wall (4) at least between a first position and a second position of the chamber (2), the chamber (2) having cross-sections of different cross-sectional areas and differing circumferential lengths at the first and second longitudinal positions, and at least substantially continuously different cross-sectional areas and circumferential lengths at intermediate longitudinal positions between the first and second longitudinal positions, the cross-sectional area and circumferential length at the second longitudinal position being smaller than the cross-sectional area and circumferential length at the first longitudinal position, and the piston (1) includes a rotatable member (12) for suspension of the sealing (8,9).

A single-way damping plunger cylinder includes a cylinder body (3), a piston rod (4), a piston (6) and a sleeve (2), the piston (6) dividing the cylinder body (3) into a first cylinder chamber (31) and a second cylinder chamber (32), a first end of the first oil passage (40) being communicated with the first cylinder chamber (31) via the second oil passage (41) and a second end of the first oil passage (40) being communicated with the second cylinder chamber (32), the valve (5) movably disposed in the second oil passage (41) to open or close a direct communication of the first and second oil passages (40,41); a damping oil passage (50) defined in the valve (5) to communicate the first oil passage (40) with the second oil passage (41). A forklift is also provided.

Disclosed is a hydraulic damper wherein the main damper tube has a narrowed section and it includes at least one additional piston assembly adapted to be received in the narrowed section to generate additional damping force. The piston assembly comprises a compression valve assembly and a rebound valve assembly each comprising at least one deflective disc. A sealing ring assembly is disposed between the compression and rebound valve assembles and comprises a first annular member having a plurality of channels covered by the deflective disc of the compression valve assembly; a second annular member having a plurality of channels, covered by the deflective disc of the rebound valve assembly; an axial projection between the annular members radially internal to the axial channels; and a sealing ring displaceable axially between the annular members and radially over the axial projection and adapted to cooperate with the narrowed section of the tube.

A device having two glands leading a piston rod the glands being located at one side of a piston, whereas an inner gland divides the chamber inside the closed cylinder into a working chamber limited axially by an inner surface of a bottom and into a lubricating chamber limited axially by the inner surface of the outer gland. The working chamber has a flow zone shaped as the cylinder with its inner diameter increased, placed adjacent to the inner gland, as well as the compression zone, whereas the inner diameter of the cylinder is slidingly fitted with the outer diameter of the piston.

A damping valve for a hydraulic damper comprises a valve housing comprising an inlet chamber and an outlet chamber. A valve seat is arranged between the inlet chamber and the outlet chamber. A valve element having a cylindrical first portion is slidably received in a cylindrical bore of the valve housing. A second portion of the valve element has a valve surface for selectively engaging and disengaging the valve seat to allow passage of hydraulic fluid between the inlet chamber and the outlet chamber. A spring element is mounted within the valve housing for biasing the valve element into engagement with the valve seat.

A stopper mechanism includes a second cylinder provided at an end portion in an inner cylinder, and a second piston configured to move along with movement of a piston rod to be capable of being fit-inserted through the second cylinder. The second piston includes a stopper coupled to the piston rod, a castle integrated with the stopper by plastic flow to form a ring groove on an outer periphery of the second piston between the castle and the stopper, and a piston ring fixed into a ring groove formed by the stopper and the castle so that the piston ring is displaceable in the ring groove in an axial direction and is retained in the ring groove, and has an annular shape with both ends in a circumferential direction which are formed by partially cutting the piston ring.

A damping unit includes a cylinder which is filled with a damping fluid and in which a piston rod is guided, the piston rod associated with a bottom surface which has at least one axial through-hole which defines an effective flow cross section for the damping fluid; wherein the piston rod includes: a sleeve element which is fixed on the piston rod in the axial direction; a piston bottom element which is supported on the piston rod so as to be axially slidable and includes the bottom surface; a resilient element; and a termination element which is fixed on the piston rod in the axial direction and forms an indirect or direct stop for the piston bottom element in the insertion direction of the piston rod.