Shaft seals

Claim 1

In a shaft seal comprising a molded sealing ring of resilient material having a peripheral sealing lip, said lip having inner and outer, mutually convergent, peripheral frustoconical surfaces, respectively facing towards and away from the fluidsealing side of the seal, a continuous circumferential sealing band coaxial with said ring being defined on said lip by the convergence of said frustoconical surfaces, at least one first vane member extending arcuately around part of said outer frustoconical surface, said first vane member having two ends which intercept said continuous circumferential sealing band respectively in opposite circumferential directions at an angle of not more than 20* to the plane of said sealing band, said first vane member also having flank surfaces between said ends, said ends of said first vane member presenting a pair of oppositely directed flank surfaces progressively joining said sealing band, and said pair of flank surfaces being operative as vane surfaces, for one direction and the other respectively of relative shaft rotation when the seal is in use, to sweep back to the sealing band fluid leaking past said sealing band; the improvement which consistS in the provision of at least one second vane member corresponding in all respects to said first vane member except that said second vane member so extends arcuately around said outer frustoconical surface that said vane members mutually intersect and said second vane member presents a second pair of oppositely directed flank surfaces progressively joining said sealing band and operative as vane surfaces in like manner as said vane surfaces of said first vane member.