US2983341A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-erecting derrick
Assignee: Dresser Industries Inc
•
Filing: 1956-02-01
•
Granted: 1961-05-09
•
Expires: 1976-02-01
Abstract
No abstract record available.
Inventors
- 👤 John P Selberg
- 👤 William H Griffith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:47
CPC Classifications
E; E21; E21B; E21B15/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1054737A
Cited
US1819031A
Cited
US2345253A
Cited
US2283049A
Cited
US2336432A
Cited
US2421913A
Cited
US2597958A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-05-08 | 1964-11-07 | 1965-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-05-08 | 1968-11-07 | 1969-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-05-08 | 1972-11-07 | 1973-05-09 | $7700.00 | Window Closed / Lapsed |