Patent US3827701A successfully refreshed from Google Patents.
US3827701A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oil seal for use in rotary piston internal combustion engine
Assignee: Nippon Piston Ring Co Ltd
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Filing: 1972-04-07
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Granted: 1974-08-06
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Expires: 1992-04-07
Abstract
Abstract An oil seal for use in a rotary piston internal combustion engine which has at least one annular groove provided on an annular sliding face formed with an axial outer surface of the oil seal and adjacent to and facing an inside wall face of a side housing of the engine.
Inventors
- 👤 H Sakamaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:34
CPC Classifications
F; F01; F01C; F01C19/00; F01C19/08; F16; F16J; F16J15/00; F16J15/16; F16J15/34
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
74 words
An oil seal for use in a rotary piston internal combustion engine, wherein said seal has an annular sliding face on an axial outer side thereof in contact with a side wall housing, the improvement wherein said sliding face comprises at least two regularly spaced, non-communicating annular grooves therein facing said side wall, and wherein each of said grooves is rectangular in cross section and each has a depth approximating three times its width.
Claim 2
Dependent Claim
74 words
An oil seal for use in a rotary piston internal combustion engine, wherein said seal has an annular sliding face on an axial outer side thereof in contact with a side wall housing, the improvement wherein said sliding face comprises at least two regularly spaced, non-communicating annular grooves therein facing said side wall, and wherein each of said grooves is rectangular in cross section and each has a depth approximating three times its width.
Claim 3
Dependent Claim
33 words
The oil seal as set forth in claim 1, wherein the width of said groove is 0.1 mm to 0.5 mm and the depth of said groove is 0.2 mm to 1.2 mm.
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) | 1977-08-05 | 1978-02-04 | 1978-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-05 | 1982-02-04 | 1982-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-05 | 1986-02-04 | 1986-08-06 | $7700.00 | Window Closed / Lapsed |