The first piston body includes a first passage which has a first opening that opens to the first chamber on the coupling surface with the second piston body and extends in the axial direction, and a second passage which has a second opening on the coupling surface, extends in the axial direction and has a third opening that opens to the second chamber, the second piston body is coupled to the first piston body to prevent direct communication with the first chamber of the second opening, the second opening has an inner opening portion that opens further inward in the radial direction than the first opening, and the inner opening portion communicates with a third passage formed in the second piston body.

A hydraulic shock absorber including a housing and an absorber unit. The absorber unit is movable relative to the housing in the axis direction of an absorber unit middle axis A-A and includes a piston which is arranged on a piston rod and which subdivides the housing into a first and a second working space which is filled with damping fluid.

A damping valve includes: a ring-shaped leaf valve having either one of an outer circumference and an inner circumference as a free end, the free end being allowed to be deflected toward both sides in the axial direction; a ring-shaped opposing portion that opposes the free end of the leaf valve with a gap; a first sub leaf valve stacked on one side of the leaf valve in the axial direction; and a first passage formed in the leaf valve so as to extend in parallel with the gap, the first passage being configured to be opened when the leaf valve is deflected in the direction away from the first sub leaf valve.

A valve seat member is provided with: a first seat arranged so as to be spaced apart from an opening of a port; a second seat connected to the first seat at both ends so as to surround the opening of the port; an island portion arranged on the first seat side of the opening of the port in a region surrounded by the first seat and the second seat such that a hollow space is formed between the island portion and the first seat; and a passage configured to extend through the island portion to allow communication between the port and the hollow space.

A hydraulic shock absorber including a housing and an absorber unit. The absorber unit is movable relative to the housing in the axis direction of an absorber unit middle axis A-A and includes a piston which is arranged on a piston rod and which subdivides the housing into a first and a second working space which is filled with damping fluid.

A vehicle suspension damper including: a cylinder; a piston assembly; and an adjuster, wherein the piston assembly compresses fluid as it moves within the cylinder and the adjuster obstructs fluid flow from a first side of a damping piston of the piston assembly to a second side of the damping piston.

A restriction for a vibration damper, comprising an annular element with variable diameter which is supported by a support and which occupies a restriction position depending on a flow velocity of a damping medium within the restriction proceeding from an open position through a radial closing movement in direction of a flow guiding surface. The annular element has at least two legs supported so as to be movable around a pivot bearing.

A hydraulic damper assembly comprises a housing defining a fluid chamber. A piston is slidably disposed in the fluid chamber dividing the fluid chamber into a compression and a rebound chamber. A piston rod couples to the piston for movement between a compression and a rebound stroke. The piston has a compression surface and a rebound surface. The piston defines at least one compression channel, at least one rebound channel, and at least one additional channel. A compression valve covers the at least one compression channel. A rebound valve covers the at least one rebound channel. A proportional bleeding system located between the compression valve and the piston to establish a bleeding flow passage between the at least one rebound chamber and the at least one additional channel for reducing operation harshness of the hydraulic damper assembly. A piston for the hydraulic damper assembly is also disclosed herein.

A damping valve includes a damping valve body with an annular groove which has a base and which is limited by an inner valve seat surface and an outer valve seat surface for at least one valve disk. The base of the annular groove has a maximum distance from the valve seat surface along a circumferential area and has a minimum axial distance from the valve seat surface in another circumferential area.

One embodiment provides a damping force generator. The damping force generator includes: a valve body having a compression-side inlet port into which the oil pushed by the piston flows; and a compression-side damping valve provided so as to block a port outlet and elastically deformed according to pressure of the oil flowing into the compression-side inlet port to thereby exhibit damping force. An opening cross-sectional area of a port inlet opening is larger than a passage cross-sectional area of the compression-side inlet port.