Patent US2635933A successfully refreshed from Google Patents.
US2635933A
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Piston ring construction
Assignee: Wilkening Manufacturing Co
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Filing: 1949-09-28
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Granted: 1953-04-21
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Expires: 1969-09-28
Abstract
No abstract record available.
Inventors
- 👤 Carl F Engelhardt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:50
CPC Classifications
F; F16; F16J; F16J9/00; F16J9/06; F16J9/061; F16J9/063
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US345767A
Cited
US1767711A
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US2044272A
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US2183199A
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US2229578A
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US2333457A
Cited
US2293450A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-04-20 | 1956-10-20 | 1957-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-04-20 | 1960-10-20 | 1961-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-04-20 | 1964-10-20 | 1965-04-21 | $7700.00 | Window Closed / Lapsed |