US2573689A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Internal-combustion engine variable combustion chamber
Assignee: Individual
•
Filing: 1947-12-12
•
Granted: 1951-11-06
•
Expires: 1967-12-12
Abstract
No abstract record available.
Inventors
- 👤 Butler Frank David
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:31
CPC Classifications
F; F16; F16J; F16J1/00; F16J1/10; F02; F02B; F02B75/00; F02B75/04; F02B75/044; F02D; F02D15/00; F02D15/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US752936A
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US878783A
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US1252269A
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US1610137A
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US1637245A
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US1825163A
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US2134995A
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US2107795A
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US2380907A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-11-05 | 1955-05-07 | 1955-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-11-05 | 1959-05-07 | 1959-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-11-05 | 1963-05-07 | 1963-11-06 | $7700.00 | Window Closed / Lapsed |