Air pump and shock absorber piston - has ring seal which slides in tapered groove

摘要

A piston (1) has an O-ring seal (3) set into an axially tapered groove (2). During the compression stroke the diameter of the O ring (3) increases to achieve a seal, while the diameter is reduced as the piston returns. The flange (6) contacted by the seal (3) during the return stroke is webbed, grooved or studded. ADVANTAGE - The piston can be made from a single casting.