US Patent 7798052 Fluid pressure cylinder

First and second cushion rings are arranged respectively on both end surfaces of a piston constituting part of a fluid pressure cylinder, through fitting grooves. The first and second cushion rings are formed with substantially hollow cylindrical shapes by press working a metal material, wherein the cushion rings effectuate a cushioning action, which decelerates the displacement speed of the piston, as a result of being displaced in the axial direction together with the piston and being received and accommodated within a recess of the head cover and a rod hole of the rod cover.