Fluid pressure cylinders provided with impact absorbing mechanisms

Abstract

A fluid pressure cylinder includes a cylinder body, a piston accommodated in the cylinder body to define first and second pressure chambers therein, means for supplying fluid to each chamber to reciprocate the piston between a first stroke end and a second stroke end, first and second bumper surfaces, an annular cushion retainer connected to the first bumper surface, and an elastomeric cushion for deforming and cushioning an impact produced when the piston reaches the first stroke end. The bumper surfaces approach each other when the piston reaches the first stroke end and separate from one another when the piston moves toward the second stroke end. The cushion has a shape corresponding generally to a hollow conical section. The cushion includes a base section retained by the cushion retainer and a buffer section joined to the base section. The buffer section has an outer surface for contacting the second bumper surface and an inner surface that faces the first bumper surface. The outer surface forms a circular seal with the second bumper surface when the piston approaches the first stroke end. The cushion is flexed such that the buffer section moves toward the first bumper surface. The buffer section moves away from the first bumper surface when the piston moves towards the second stroke end.