US3814445A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Seal assembly
Assignee: De Zurik Corp
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Filing: 1972-02-10
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Granted: 1974-06-04
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Expires: 1992-02-10
Abstract
Abstract An improved seal assembly includes a ''''Teflon'''' seal ring of rectangular cross-section and a resilient O-ring disposed in a stepped circumferential recess in the piston of a linear actuator. Two axially spaced grooves in the outer surface of the seal ring opposite the sidewalls of the inner portion of the stepped recess concentrate the sealing force of the compressed Oring on the central portion of the seal ring. The edges of the seal ring outboard of the grooves are positively backed-up by shoulders in the stepped recess to prevent twisting and roll out of the seal assembly. The seal ring is loosely fit into the outer portion of the stepped recess to reduce friction on the leading and trailing edges and to admit entrance of the fluid medium from the high pressure side of the piston into the step recess to increase the sealing force exerted by both the seal ring and the O-ring.
Inventors
- 👤 J Bitzan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:54
CPC Classifications
F; F16; F16J; F16J15/00; F16J15/16; F16J15/32; F16J15/3204; F16J15/3208
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
304 words
A seal assembly for sealing the space between an internal wall of a cylinder and a piston reciprocally mounted therein, comprising: an annular recess in one of said cylinder and piston, said recess having a first portion of given axial width and a second portion of greater axial width, said second portion of said annular recess being closer to the other of said cylinder and piston than said first portion of said annular recess, the axial ends of said first portion being spaced axially from the axial ends of said second portion to form shoulders in said recess; a sealing ring in said second portion of said annular recess, said sealing ring having an axial width that is less than that of said second portion of said annular recess and greater than that of said first portion of said annular recess; said sealing ring having a first axially extending surface facing said other of said cylinder and piston and a second surface axially extending from one end of said sealing ring to another end of said sealing ring and facing said shoulder, said second surface being spaced from said shoulder to permit fluid to be sealed to pass between said shoulder and said sealing ring; a pair of annular grooves axially spaced in the first surface of said sealing ring to divide said sealing ring into a central band and sidebands, at least a portion of each of said grooves axially overlapping one of said shoulders; and a resilient ring radially compressed between an axially extending wall of said first portion and said central band of said sealing ring, whereby said resilient ring and said fluid cooperate to force said central band of said sealing ring into fluid tight engagement with said other of said cylinder and piston while reducing wear of said sidebands.
Claim 2
Dependent Claim
304 words
A seal assembly for sealing the space between an internal wall of a cylinder and a piston reciprocally mounted therein, comprising: an annular recess in one of said cylinder and piston, said recess having a first portion of given axial width and a second portion of greater axial width, said second portion of said annular recess being closer to the other of said cylinder and piston than said first portion of said annular recess, the axial ends of said first portion being spaced axially from the axial ends of said second portion to form shoulders in said recess; a sealing ring in said second portion of said annular recess, said sealing ring having an axial width that is less than that of said second portion of said annular recess and greater than that of said first portion of said annular recess; said sealing ring having a first axially extending surface facing said other of said cylinder and piston and a second surface axially extending from one end of said sealing ring to another end of said sealing ring and facing said shoulder, said second surface being spaced from said shoulder to permit fluid to be sealed to pass between said shoulder and said sealing ring; a pair of annular grooves axially spaced in the first surface of said sealing ring to divide said sealing ring into a central band and sidebands, at least a portion of each of said grooves axially overlapping one of said shoulders; and a resilient ring radially compressed between an axially extending wall of said first portion and said central band of said sealing ring, whereby said resilient ring and said fluid cooperate to force said central band of said sealing ring into fluid tight engagement with said other of said cylinder and piston while reducing wear of said sidebands.
Claim 3
Dependent Claim
30 words
A seal assembly as defined in claim 1, wherein said one of said cylinder and piston is said piston, and said other of said cylinder and piston is said cylinder.
Claim 4
Dependent Claim
24 words
A seal assembly as defined in claim 2, wherein said sealing ring is made of a flourinated hydrocarbon polymer principally comprised of polymerized tetraflouroethylene.
Claim 5
Dependent Claim
28 words
A seal assembly as defined in claim 3, wherein said sealing ring is generally rectangular in axial cross-section and said resilient ring is generally circular in axial cross-section.
Claim 6
Dependent Claim
54 words
A seal assembly as defined in claim 4, wherein said central band is slightly wider than said side bands, said grooves having a depth between about one-fifth and about one-third of the radial thickness of said sealing ring, and said resilient ring engaging said second surface of said sealing ring on the central band.
Claim 7
Dependent Claim
23 words
A seal assembly as defined in claim 5, wherein said resilient ring engages one side of said first portion of said annular recess.
References Cited (Backward Citations)
GB756460A
Cited
US3149849A
Cited
US3268235A
Cited
DE1901274A1
Cited
US3678809A
Cited
US3663024A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-03 | 1977-12-03 | 1978-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-03 | 1981-12-03 | 1982-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-03 | 1985-12-03 | 1986-06-04 | $7700.00 | Window Closed / Lapsed |