Abstract: A hydraulic damper includes a dual-tube type housing consisting of inner and outer tubes, a piston slidably disposed in the inner tube and dividing the interior thereof into two oil chambers, a piston rod secured to the piston and extending to the outside of the housing, a reservoir chamber defined between the inner and outer tubes and containing therein oil and gas, a passage connecting one of the oil chambers through which the piston rod extends with the gas containing portion of the reservoir chamber, and a valve member formed of a resilient material and having a lip portion acting as one-way valve for allowing fluid flow in the passage only in the direction from the one oil chamber to the reservoir chamber. A substantial portion of the radially inner surface of the lip portion is supported by a rigid annular retaining member.

Abstract: A gas spring comprises a cylindrical outer sheath having a stopper holding structure on the inner surface, a rod and piston unit slidably received in the outer sheath, a rod guide and a packing sealably fitted in the outer sheath, and a stopper freely received in the outer sheath for limiting the upward movement of the piston and having engaging structure on the outer surface to engage on the stopper holding structure to thereby hold the stopper in position in the outer sheath.

Abstract: A shock absorber and suspension strut unit having an outer cylinder containing a predetermined amount of a damping liquid. An inner cylinder is mounted rigidly and concentrically in the outer cylinder and is arranged so as to form an intermediate concentric space between the cylinders. A movable piston rod assembly is movable relative to the double-cylinder assembly and has a piston slidably arranged within the inner cylinder for movement therealong. Check valves are provided in the piston for permitting selective fluid flow from one side of the piston to the other. Further, one or more communication passages are provided in an end of the inner cylinder which abuts the enclosed and the outer cylinder for allowing fluid passage therethrough mutually between a liquid chamber formed below the piston within the inner cylinder and lower part of the annular space formed by and between the cylinders. Thus, these spaces are a substantially unified liquid chamber.

Abstract: A dual tube hydraulic shock absorber includes an inner tube or a cylinder slidably receiving a piston therein, a piston rod secured to the piston and extending out of the cylinder through the upper end thereof, an outer tube surrounding the cylinder to define around the outer periphery of the cylinder an annular reservoir chamber, working liquid filled in the cylinder and in the lower portion of the reservoir chamber, pressurized gas filled in the upper portion of the reservoir chamber, a seal member engaging with the piston rod to seal the shock absorber from the outside, a path connecting the lower portion of the reservoir chamber with the interior of the cylinder, a passage connecting the upper portion of the reservoir chamber with the interior of the cylinder, and check valve means disposed in the passage. The check valve means is formed separately from the seal member and comprises an annular resilient valve member secured to a retaining member formed of a metal.