Piston ring

摘要

A piston ring having a general shape of a cylinder with the first section in the shape of an annulus for engaging a portion of the surface of a piston to provide a fluid-tight seal with the piston and a second section in the shape of a thin-walled bowl with sealing means on the outer surface of the bowl for providing a fluid-tight seal between the ring and the cylinder wall. The ring is especially constructed for use at cryogenic temperatures of -320 DEG F and below.