Importance

Loading Importance Indicators...

Abstract

A double-acting pneumatic cylinder has a housing with a cylindrical chamber therein. A cylindrical piston is supported coaxially in the chamber for movement axially thereof and has a circumferential groove in the outer surface thereof. A pair of spaced, facing annular surfaces and a radially outwardly extending annular rib are provided in the groove, the rib being axially intermediate the annular surfaces. Two passageways in the housing communicate with the chamber on opposite sides of the piston for supplying compressed air to the chamber. A resilient O-ring encircles the piston within the groove and has annular bands of engagement with the chamber and the rib. The O-ring is transversely movable within the groove between two positions having annular bands of engagement with the respective annular surfaces in the groove in response to low air pressure selectively supplied to the chamber through the two passageways. The O-ring deforms elastically in response to a substantial increase in the supplied air pressure so as to increase the contact area and pressure along the annular bands of engagement with the housing chamber and one of the annular surfaces.

Loading the Abstract Image...

First Claim