Patent US2663843A successfully refreshed from Google Patents.
US2663843A
Expired / Lapsed
US
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Magnetic gradiometer
Assignee: Gulf Research and Development Co
•
Filing: 1950-08-03
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Granted: 1953-12-22
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Expires: 1970-08-03
Abstract
No abstract record available.
Inventors
- 👤 Warren E Wickerham
- 👤 Orville K Doolen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:59
CPC Classifications
G; G01; G01V; G01V3/00; G01V3/08; G01V3/087; G01R; G01R33/00; G01R33/02; G01R33/022
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2406870A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-12-21 | 1957-06-22 | 1957-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-12-21 | 1961-06-22 | 1961-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-12-21 | 1965-06-22 | 1965-12-22 | $7700.00 | Window Closed / Lapsed |