Combination lip seal and o-ring

Claim 2

A fluid seal comprising: a ring member of resilient flowable material including a rearward section having a one periphery of at least a semicircular profile at one end overlying a square section; a forward section integrated with the rearward section and having a first lip angularly extending and stopping in its free state beyond the free extension point of the semicircular profile of the rearward section whereby said lip axially stiffens the seal and prevents its inversion on assembly, said forward section also terminating in a second lip of less length and angularly projecting therefrom to rest in its free state further from said ring than the surface of the square section of the rearward section therebehind; and said first lip having one surface flared into the profile of the rearward section and its underlying surface flared into the square section of the ring member below a plane passing through the center of the ring member in cross section.

Claim 3

A piston and seal assembly which is exposed to fluid under one pressure on one side and another pressure on the other side and including in combination: a stepped groove in the piston of a predetermined depth at its lowest point having a rounded shoulder thereabove facing away from the side of the piston exposed to the one pressure; and an annular seal having a face with lips of differing length one of which rests on said rounded shoulder and another face comprising a rounded portion in its surface from which the longest lip projects and a square portion thereunder which forms a flat surface with the shortest lip at the bottom of the groove.

Claim 4

A piston and seal assembly which is exposed to fluid under one pressure on one side and another pressure on the other side and including in combination: a stepped groove in the piston of a predetermined depth at its lowest point having a rounded shoulder thereabove facing away from the side of the piston exposed to the one pressure; and an annular seal having a face with lips of differing length one of which rests on said rounded shoulder and another face comprising a rounded portion in its surface from which the longest lip projects and a square portion thereunder which forms a flat surface with the shortest lip at the bottom of the groove.

Claim 5

In a fluid motor: a housing defining a bore therewithin; a piston slidable in said bore; a circumferentially extending groove in said piston; an annular seal in said groove; said groove being stepped to present an inner circumferential surface and an intermediate circumferential surface disposed between said inner circumferential surface and the outer circumferential surface of the piston, said inner and intermediate surfaces defining a shoulder therebetween; said seal having a base section disposed in the portion of the groove defined by said inner surface, a lip section engaging the wall of the bore extending axially from said base section into the portion of the groove defined by said intermediate surface, and another section extending from said base section toward the wall of the bore; the corner formed by the intersection between said shoulder and said intermediate circumferential surface engaging one side of said lip section to urge the other side of said lip section into engagement with the wall of the bore.

Claim 6

In a fluid motor: a housing defining a bore therewithin; a piston slidable in said bore; a circumferentially extending groove in said piston; an annular seal in said groove; said groove being stepped to present an inner circumferential surface and an intermediate circumferential surface disposed between said inner circumferential surface and the outer circumferential surface of the piston, said inner and intermediate surfaces defining a shoulder therebetween; said seal having a base section disposed in the portion of the groove defined by said inner surface, a lip section engaging the wall of the bore extending axially from said base section into the portion of the groove defined by said intermediate surface, and another section extending from said base section toward the wall of the bore; the corner formed by the intersection between said shoulder and said intermediate circumferential surface engaging one side of said lip section to urge the other side of said lip section into engagement with the wall of the bore.

Claim 7

The invention of claim 3: said corner having a radiused surface thereon for engaging said lip.

Claim 8

The invention of claim 3: said base section being substantially rectangular in cross section to present a substantially flat lower edge engaging said inner surface.