US2517198A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas anchor
Assignee: Shell Development Co
•
Filing: 1946-09-03
•
Granted: 1950-08-01
•
Expires: 1966-09-03
Abstract
No abstract record available.
Inventors
- 👤 Walton E Gilbert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:00
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/34; E21B43/38
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-07-31 | 1954-01-30 | 1954-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-07-31 | 1958-01-30 | 1958-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-07-31 | 1962-01-30 | 1962-08-01 | $7700.00 | Window Closed / Lapsed |