US3390531A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Offshore drilling platform
Assignee: Shell USA Inc
•
Filing: 1967-04-14
•
Granted: 1968-07-02
•
Expires: 1987-04-14
Abstract
No abstract record available.
Inventors
- 👤 Lowell P Johnston
- 👤 Dillard S Hammett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 05:21
CPC Classifications
E; E02; E02B; E02B17/00; E02B17/02; E02B17/027; E02B17/0004; E21; E21B; E21B7/00; E21B7/04; E21B7/043
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1900163A
Cited
US3315473A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-07-02 | 1972-01-01 | 1972-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-07-02 | 1976-01-01 | 1976-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-07-02 | 1980-01-01 | 1980-07-02 | $7700.00 | Window Closed / Lapsed |