JPH09-014328A published by the Japan Patent Office in 1977 discloses a rebound cushion for damping an impact accompanying protrusion of a piston of a strut type hydraulic shock absorber to the protruding limiting position.
The rebound cushion is formed in a cylindrical shape made of low rigidity rubber such as nitrile-butadiene rubber or synthetic rubber and fitted on the outer circumference of the piston rod. The piston rod is provided with a flange for supporting the rebound cushion in a protruding direction of the piston rod.
The piston rod is inserted into a cylinder, and a rod guide is provided at an upper end of the cylinder. The piston rod penetrates the rod guide and the rebound cushion is fitted to an inserted part of the piston rod in the cylinder. An inner space of the cylinder is filled with working oil. The rod guide guides the protrusion and retreat of the piston rod and also defines the protruding limiting position of the piston rod by preventing further displacement of the rebound cushion when in contact with the rebound cushion.
When the piston rod protrudes to the protruding limiting position, the rebound cushion collides against the rod guide and elastically deforms, thereby damping the impact caused by the collision.