Patent US3554568A successfully refreshed from Google Patents.
US3554568A
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US
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Piston and piston ring combination
Assignee: Dana Inc
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Filing: 1968-08-19
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Granted: 1971-01-12
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Expires: 1988-08-19
Abstract
Abstract DISCLOSED HEREIN IS THE COMBINATION OF A WEDGESHAPED, PRESSURE-BACKED PISTON RING AND PISTON, WITH THE RING LOCATED CLOSELY ADJACENT THE UPPER END OF THE PISTON. THE TOP LAND OF THE PISTON IS RELIEVED TO ALLOW THE COMBUSTION GASES TO EXERT POSITIVE DOWNWARD AND OUTWARD PRESSURE ON THE RING.
Inventors
- 👤 Robert W Heid Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:14
CPC Classifications
F; F16; F16J; F16J9/00; F16J9/12; F16J9/20
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-11 | 1974-07-13 | 1975-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-11 | 1978-07-13 | 1979-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-11 | 1982-07-13 | 1983-01-12 | $7700.00 | Window Closed / Lapsed |