US3453532A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Metal detector including a hartley oscillator with field effect transistor and delayed automatic amplitude stabilizing feedback
Assignee: ROBERT F GARDINER
•
Filing: 1967-09-06
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Granted: 1969-07-01
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Expires: 1987-09-06
Abstract
No abstract record available.
Inventors
- 👤 Robert F Gardiner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:49
CPC Classifications
G; G01; G01V; G01V3/00; G01V3/08; G01V3/10; G01V3/101; G01V3/102
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2807720A
Cited
US2919413A
Cited
US2907017A
Cited
US3201774A
Cited
US3202909A
Cited
US3329906A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-06-30 | 1972-12-30 | 1973-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-06-30 | 1976-12-30 | 1977-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-06-30 | 1980-12-30 | 1981-07-01 | $7700.00 | Window Closed / Lapsed |