Patent US4421328A successfully refreshed from Google Patents.
US4421328A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Half-keystone compression ring
Assignee: KAYDON ACQUISITION Inc A DE CORP
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Filing: 1982-09-29
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Granted: 1983-12-20
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Expires: 2002-09-29
Abstract
Abstract An improved half-keystone compression ring for use in an internal combustion engine. The improved ring's bottom side is essentially flat, radially and circumferentially, in the closed operating position.
Inventors
- 👤 Kent W. Thurston
- 👤 Jesse H. Barnes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:39
CPC Classifications
F; F16; F16J; F16J9/00; F16J9/12; F16J9/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
51 words
An improved half-keystone compression ring for use in an internal combustion engine, the improvement comprising an essentially flat bottom side of said ring when said ring is in the closed operating position, said bottom side forming a nominal angle of between 0° and plus or minus 8' with a horizontal surface.
Claim 2
Dependent Claim
51 words
An improved half-keystone compression ring for use in an internal combustion engine, the improvement comprising an essentially flat bottom side of said ring when said ring is in the closed operating position, said bottom side forming a nominal angle of between 0° and plus or minus 8' with a horizontal surface.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-19 | 1987-06-20 | 1987-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-19 | 1991-06-20 | 1991-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-19 | 1995-06-20 | 1995-12-20 | $7700.00 | Window Closed / Lapsed |