Patent US1961541A successfully refreshed from Google Patents.
US1961541A
Expired / Lapsed
US
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Portable derrick
Assignee: Individual
•
Filing: 1930-07-09
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Granted: 1934-06-05
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Expires: 1950-07-09
Abstract
No abstract record available.
Inventors
- 👤 William G Adams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:37
CPC Classifications
B; B66; B66C; B66C23/00; B66C23/18; B66C23/36; B66C2700/00; B66C2700/03; B66C2700/0321; B66C2700/0357; B66C2700/0364
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) | 1937-06-04 | 1937-12-04 | 1938-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1941-06-04 | 1941-12-04 | 1942-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1945-06-04 | 1945-12-04 | 1946-06-05 | $7700.00 | Window Closed / Lapsed |