US3521153A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Geophysical prospecting with electromagnetic waves of extremely low frequency
Assignee: American Smelting and Refining Co
•
Filing: 1968-07-11
•
Granted: 1970-07-21
•
Expires: 1988-07-11
Abstract
No abstract record available.
Inventors
- 👤 Calvin K Moss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:57
CPC Classifications
G; G01; G01V; G01V3/00; G01V3/15; G01V3/17
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1676779A
Cited
US1818331A
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US1792910A
Cited
US2172688A
Cited
US2268106A
Cited
US2731596A
Cited
US2992325A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-07-20 | 1974-01-19 | 1974-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-20 | 1978-01-19 | 1978-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-20 | 1982-01-19 | 1982-07-21 | $7700.00 | Window Closed / Lapsed |