Patent US4704680A successfully refreshed from Google Patents.
Patent US868841A successfully refreshed from Google Patents.
US868841A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotary engine.
Assignee: Individual
•
Filing: 1907-06-03
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Granted: 1907-10-22
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Expires: 1927-06-03
Abstract
No abstract record available.
Inventors
- 👤 Homer H Calkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:42
CPC Classifications
F; F01; F01C; F01C21/00; F01C21/08; F01C21/0809; F04; F04C; F04C2/00; F04C2/30; F04C2/34; F04C2/344; F04C2/3446
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) | 1910-10-21 | 1911-04-22 | 1911-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1914-10-21 | 1915-04-22 | 1915-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1918-10-21 | 1919-04-22 | 1919-10-22 | $7700.00 | Window Closed / Lapsed |