A damper device includes an outer cylinder, an inner cylinder disposed inside the outer cylinder and having an inner chamber, a lower open end, and an upper closed end wall with a vent hole, a piston disposed in the inner chamber and having a passageway, a check valve coupled to the passageway to permit only upward flowing of a working fluid in the inner chamber through the passageway, and a piston rod having a lower rod end disposed outwardly of the outer cylinder, and an upper rod mounted to permit the piston to slide with the piston rod. The sliding of the piston rod is dampened by sliding of the piston in the inner chamber. A hinge assembly including the damper device is also disclosed.

A pneumatic hydraulic retractable device includes a fluid pressure cylinder having a cylinder body and a plug seat disposed in the cylinder body, a piston rod movably disposed in the fluid pressure cylinder, a control valve set having a valve seat disposed at the piston rod and forms an upper fluid chamber and a lower fluid chamber with the cylinder body therebetween, and a valve rod disposed in the valve seat for controlling communication between the upper and lower fluid chambers, and a pressure relief element forming a pressure relief gap with the piston rod. The pressure relief gap communicates with the lower fluid chamber through a communication portion of the pressure relief element. As such, when the valve rod is opened, the fluid is allowed to flow between the lower fluid chamber and the pressure relief gap through the communication portion for reducing airtight effect.

A vehicle suspension damper comprises a cylinder and a piston assembly including a damping piston along with working fluid within the cylinder. A bypass permits fluid to avoid dampening resistance of the damping piston. A fluid path through the bypass is controlled by a valve that is shifted by a piston surface when the contents of at least one predetermined volume is injected against the piston surface which acts upon the valve. In one embodiment, the bypass is remotely operable.

A vehicle suspension damper comprises a cylinder and a piston assembly including a damping piston along with working fluid within the cylinder. A bypass permits fluid to avoid dampening resistance of the damping piston. A fluid path through the bypass is controlled by a valve that is shifted by a piston surface when the contents of at least one predetermined volume is injected against the piston surface which acts upon the valve. In one embodiment, the bypass is remotely operable.

A spring system that includes an adjustable spring system that is operated by a motor.

A spring system that includes an adjustable spring system that is operated by a motor.

A spring system that includes an adjustable spring system that is operated by a motor.

A spring system that includes an adjustable spring system that is operated by a motor.

A method for damping a movement of a door system of a vehicle that is equipped with a damping system having an adjustable and controllable damping action. A movement of the door system between a closed position and an open position is damped in a controlled manner. A measurement of the change in speed of the speed of movement of the door system is calculated and if the change in speed exceeds a predefined limit value, a set, gentle damping action is changed over to a greater damping action.

A hydraulic shock absorber includes a piston, a damper tube, a suspension spring, a plunger, a jack chamber, a pump case, a pump piston, a screw shaft, and a drive unit. Both end surfaces of the pump piston in a reciprocating direction are a first end surface demarcating the pump chamber, and a second end surface demarcating the gas chamber, the second end surface having a screw hole into which the screw shaft is screwed. The pump piston includes a space portion between a bottom plate defining the first end surface and the screw hole. The screw shaft has a through-hole connecting the gas chamber with the space portion.