Air brake hose coupler gasket

Claim 1

In a gasket for a hose coupler of a railroad car air brake line or the like, comprising an annular one-piece body of resilient compressible material including an annular radially extending outer portion adapted to be received in a groove in the coupler and an annular axially extending inner portion having a mating surface at one axial end of said body and an annular axially projecting protuberance at the other axial end of said body, said mating surface being adapted to seal against the corresponding matingsurface of a second gasket and said protuberance having a tapered configuration in cross-section with a relatively thick base portion and an outer tip portion adapted to be compressed into sealing engagement with the wall of the coupler groove upon installation of the gasket in the coupler groove; the improvement which comprises: an annular sealing lip at said other axial end of said body concentrically spaced between said protuberance and the outer periphery of said annular radially extending outer portion, said lip being thin and flexible compared to said protuberance, and said gasket body being recessed between said protuberance and said lip to provide an annular pocket, said lip extending generally axially from said other end of said body and being inclined inwardly toward said protuberance before installation of the gasket in the coupler groove and being adapted to be displaced further toward said protuberance upon installation of the gasket in the coupler groove, thereby compressing said lip in sealing engagement against the wall of the coupler groove, and said lip also being adapted to be further compressed into sealing engagement with the wall of the coupler groove by fluid under pressure communicating with said recess.