Fluid sealing devices

Claim 1

A sealing device comprising a sealing ring of resilient material having a radially extending portion and an axially extending portion; the radially extending portion being disposed in cross section wholly at right angles to said axially extending portion, terminating remotely from said axially extending portion in an innermost circumferential sealing face, and being of constant axial thickness; said radially extending and axially extending portions together providing an outer circumferential sealing face; said axially extending portion having an inner circumferential face of a substantially larger diameter than said innermost circumferential sealing face; an annular radially outwardly directed recess being formed, adjacent to said radially extending portion, in said inner circumferential face of said axially extending portion; and said device also including a supporting ring of a material which is harder than that of the sealing ring; said supporting ring being disposed radially within the axially extending portion and to one side of the radially extending portion, said supporting ring having a radially outwardly directed flange which is of the same radial depth and axial width as and closely fits in said annular recess whereby axial interlocking, and rigid assembly, of said sealing ring and said supporting ring is provided solely by engagement of said flange with said recess; the diameter of said inner circumferential sealing face being only sufficiently less in the free state of the sealing ring than the innermost diameter of said supporting ring for that face to have an interference, and thus fluid sealing, fit with respect to an associated member when that member is so positioned as to be in engagement with the sealing ring, while said supporting ring has a clearance fit with respect to that member.