Captive plastic seal

Claim 2

A seal comprising: sealing ring means of deformable sealing material for circumscribing an object, said sealing ring means being subject to plastic flow in response to compressive loading thereof and having first and second circumferentially extending surfaces, said first and second surfaces at least partially defining first and second circumferentially extending cavities, respectively, at least when the sealing ring means is in a relaxed condition; first and second retainer rings lying at least partially within said first and second cavities, said sealing ring means and said retainer rings being generally concentrically arranged; and at least a portion of each of said retainer rings being concave in axial cross section at least when said retainer rings are in a relaxed condition, said concave portions of said first and second retainer rings opening in first and second directions, respectively, said first and second retainer rings being resiliently deformable independently of each other in the first and second directions, respectively, whereby upon compressively loading the sealing ring means the retainer rings are resiliently deformed.

Claim 3

A seal as defined in claim 1 wherein portions of said first and second surfaces are concave, said portions of said first and second surfaces at least partially defining said first and second cavities, respectively, said first and second cavities receiving at least a portion of each of the concave portions of said first and second retainer rings, respectively.

Claim 4

A seal as defined in claim 1 wherein each of said retainer rings is arcuate in axial cross section.

Claim 5

A seal as defined in claim 1 wherein saId sealing ring means includes first and second independent sealing rings separated from each other along a circumferentially extending line, said first and second sealing rings being engageable at least when the sealing ring means is compressively loaded.

Claim 6

A seal as defined in claim 1 wherein said concave portions of said retainer rings cooperate with said cavities, respectively, to mount said retainer rings on said sealing ring means.

Claim 7

A seal as defined in claim 1 wherein said retainer rings are constructed of metal.

Claim 8

A seal as defined in claim 1 wherein said sealing ring means is constructed in substantial part of a fluoro-plastic material.

Claim 9

A seal as defined in claim 1 wherein said first and second surfaces are inner and outer peripheral surfaces, respectively, said first and second retainer rings are inner and outer rings, respectively, said first and second directions are radially inwardly and radially outwardly, respectively.

Claim 10

A seal as defined in claim 1 wherein said seal is devoid of a connector between said retainer rings which is effective in tension.

Claim 11

A seal comprising: sealing ring means for circumscribing an object, said sealing ring means being constructed of a fluoro-plastic material and having inner and outer peripheral surfaces, portions of said inner and outer peripheral surfaces being concave, said portions of said inner and outer peripheral surfaces at least partially defining inner and outer cavities, respectively; said sealing ring means being subject to plastic flow in response to compressive loading thereof; inner and outer retainer rings lying at least partially within said inner and outer cavities, said sealing ring means and said retainer rings being generally concentrically arranged; and said first and second retainer rings being constructed of metal and being concave in axial cross section with the concavities opening radially inwardly and radially outwardly, respectively, said inner and outer retainer rings being resiliently deformable at least in the radial direction independently of each other with the concave configuration of said retainer rings contributing to such resilience, whereby upon axial compression and consequent plastic flow and radial expansion of the sealing ring means the retainer rings resiliently resist said radial expansion of the sealing ring means.

Claim 12

A seal comprising: sealing ring means for circumscribing an object, said sealing ring means being constructed of a fluoro-plastic material and having inner and outer peripheral surfaces, portions of said inner and outer peripheral surfaces being concave, said portions of said inner and outer peripheral surfaces at least partially defining inner and outer cavities, respectively; said sealing ring means being subject to plastic flow in response to compressive loading thereof; inner and outer retainer rings lying at least partially within said inner and outer cavities, said sealing ring means and said retainer rings being generally concentrically arranged; and said first and second retainer rings being constructed of metal and being concave in axial cross section with the concavities opening radially inwardly and radially outwardly, respectively, said inner and outer retainer rings being resiliently deformable at least in the radial direction independently of each other with the concave configuration of said retainer rings contributing to such resilience, whereby upon axial compression and consequent plastic flow and radial expansion of the sealing ring means the retainer rings resiliently resist said radial expansion of the sealing ring means.

Claim 13

A seal as defined in claim 10 wherein said sealing ring means includes first and second independent sealing rings separated from each other along a circumferentially extending region, said first and second sealing rings being engageable at least when the sealing ring means is compressively loaded.

Claim 14

A seal as defined in claim 10 wherein said sealing ring means is in the form of a single integral mass of fluoro-plastic material.