US3021909A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Means for offshore drilling
Assignee: California Research LLC
•
Filing: 1958-10-01
•
Granted: 1962-02-20
•
Expires: 1978-10-01
Abstract
No abstract record available.
Inventors
- 👤 William R Postlewaite
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:06
CPC Classifications
E; E21; E21B; E21B7/00; E21B7/12; E21B7/128
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1427524A
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US1894446A
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US1732887A
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US1699936A
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US2777669A
Cited
US2676787A
Cited
US2808229A
Cited
US2798692A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1965-02-19 | 1965-08-21 | 1966-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-02-19 | 1969-08-21 | 1970-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-02-19 | 1973-08-21 | 1974-02-20 | $7700.00 | Window Closed / Lapsed |