US2716971A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Free piston engine
Assignee: Individual
•
Filing: 1953-04-23
•
Granted: 1955-09-06
•
Expires: 1973-04-23
Abstract
No abstract record available.
Inventors
- 👤 Allen H Sykes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:37
CPC Classifications
F; F02; F02B; F02B71/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US880502A
Cited
GB225258A
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US2025362A
Cited
US2208730A
Cited
US2305772A
Cited
US2275285A
Cited
GB606336A
Cited
US2452193A
Cited
US2435970A
Cited
US2547224A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1958-09-05 | 1959-03-07 | 1959-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-09-05 | 1963-03-07 | 1963-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-09-05 | 1967-03-07 | 1967-09-06 | $7700.00 | Window Closed / Lapsed |