Sealing gasket assembly

Claim 1

A sealing assembly operable between a first cylindrical component and a second cylindrical component, which first and second components are telescopically displaceable relative to each other, said gasket comprising: an annular flange being stationary relative to one of said first and second cylindrical components, which annular flange includes a vent passage therethrough; a first sealing ring; a second sealing ring separated from said first sealing ring at a fixed distance, which first and second sealing rings cooperate to define a space therebetween; an annular piston mounted and operable in said space, which space is vented between said annular flange and said annular piston by said annular passage vent; one of said first and second sealing rings positioned in proximity to said first cylindrical component, said one sealing ring having a generally rectangular configuration in cross-section and defining an annular surface contacting said annular flange and an opposite surface away from said annular flange, a first and a second radially-viewed cylindrical boundary surface, and, a groove which extends toward said annular flange from said opposite surface, first and second sealing lips being formed, respectively, between said groove and said first and second cylindrical boundary surface; the other of said first and second sealing rings having a radially-viewed cylindrical boundary surface, said other ring cylindrical boundary surface sealingly contacting said second cylindrical component, which second cylindrical component moves relative to said sealing assembly, said other sealing ring further including an annular surface contacting said annular flange and a sloped surface extending between said annular surface contacting said annular flange and said cylindrical boundary surface and terminating in cross-section at a sharp point at said cylindrical boundary surface distal from said annular flange; said annular piston having a generally wedge-shaped cross-section with a cylindrical boundary surface to contact at least a portion of the cylindrical boundary surface of the sealing ring in proximity to said first component adjacent a sealing lip and having a curved form boundary surface conforming to said sloped form of the sealing ring in proximity to said second component, said annular piston of a material relatively harder than said sealing rings and movable in said space toward said annular flange to maintain said first and second sealing rings in sealing contact with said first and second components.