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US3920252A Expired / Lapsed US ⏱️ 0.0 years remaining

Dynamic seal for double-acting piston

Assignee: Individual
•
Filing: 1974-05-21
•
Granted: 1975-11-18
•
Expires: 1994-05-21
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Abstract

Abstract A dynamic seal for a double-acting piston slidable in a cylinder and separating a pair of chambers under pressure comprises a pair of like cup packings arranged parallel to each other and having lips directed toward each other, and a core ring between and bonded to the cup packings. The packings are constituted of a fabric-reinforced elastomer and the core ring is unreinforced and has a smaller modulus of elasticity than the cup packings. A Teflon washer may be received in a groove formed in the core ring between the cup packings, and antiextrusion elements overlying the outer ends of the cup packings may be provided to prevent damage to these cup packings. Pressure exerted on one of the cup packings is transmitted through the core ring to the other cup packing to press it tightly into engagement with the inner wall of the cylinder.

Inventors

  • 👤 Jacques Dechavanne

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 08:59
CPC Classifications
F; F16; F16J; F16J15/00; F16J15/16; F16J15/32; F16J15/3204; F16J15/3208; F16J15/3232

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 96 words
A seal for a piston slidable in a cylinder and separating a pair of chambers under pressure, said seal comprising: a pair of like single-lip cup packings of generally L-section arranged parallel to each other and having their single lips directed toward each other, said packings being constituted of a fabric-reinforced elastomer; and a core ring axially aligned between and bonded to said packings, said ring being unreinforced and having a smaller modulus of elasticity than said cup packings, said core ring having a base of its maximum axial thickness adapted to press against the piston.
Claim 2
Dependent Claim 96 words
A seal for a piston slidable in a cylinder and separating a pair of chambers under pressure, said seal comprising: a pair of like single-lip cup packings of generally L-section arranged parallel to each other and having their single lips directed toward each other, said packings being constituted of a fabric-reinforced elastomer; and a core ring axially aligned between and bonded to said packings, said ring being unreinforced and having a smaller modulus of elasticity than said cup packings, said core ring having a base of its maximum axial thickness adapted to press against the piston.
Claim 3
Dependent Claim 43 words
The seal defined in claim 1 wherein said core ring is formed with an outwardly open groove, said seal further comprising an anti-friction ring received in said groove and having a smaller coefficient of friction than said core ring and said cup packings.
Claim 4
Dependent Claim 57 words
The seal defined in claim 1, further comprising a rigid antiextrusion ring at each axial end of said seal and at least partially radially surrounding said seal, said cup packings being formed at their ends with axially and radially outward open grooves of right-angle profile, said antiextrusion rings being at least partially received formfittingly in said grooves.
Claim 5
Dependent Claim 13 words
The seal defined in claim 3 wherein said antiextrusion rings are cylindrically annular.
Claim 6
Dependent Claim 54 words
The seal defined in claim 3 wherein said antiextrusion rings are of T-section and each has a leg lying against an outer face of a respective cup packing, an arm received in a respective groove, and another arm extending away from the firstmentioned arm and lying parallel to the inner wall of said cylinder.
Claim 7
Dependent Claim 25 words
The seal defined in claim 3, further comprising a second such rigid ring mounted on said piston spaced from each of the first-mentioned antiextrusion rings.

References Cited (Backward Citations)

US2968516A Cited
US3188099A Cited
US3473814A Cited
US3636824A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-11-17 1979-05-19 1979-11-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-11-17 1983-05-19 1983-11-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-11-17 1987-05-19 1987-11-18 $7700.00 Window Closed / Lapsed

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