US2197493A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical prospecting apparatus
Assignee: Sperry Sun Well Surveying Co
•
Filing: 1939-04-11
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Granted: 1940-04-16
•
Expires: 1959-04-11
Abstract
No abstract record available.
Inventors
- 👤 Lacoste G Ellis
- 👤 John W Millington
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 19:36
CPC Classifications
G; G01; G01V; G01V3/00; G01V3/18; G01V3/20; G01V3/24
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1943-04-16 | 1943-10-16 | 1944-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-04-16 | 1947-10-16 | 1948-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-04-16 | 1951-10-16 | 1952-04-16 | $7700.00 | Window Closed / Lapsed |