Patent US4249129A successfully refreshed from Google Patents.
US4249129A
Expired / Lapsed
US
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Efficient simultaneous electromagnetic transmission or reception at different frequencies in electromagnetic mapping
Assignee: Scintrex Ltd
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Filing: 1979-04-02
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Granted: 1981-02-03
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Expires: 1999-04-02
Abstract
Abstract This invention relates to electromagnetic mapping wherein magnetic fields of two or three different and normally audio frequencies may be transmitted or received efficiently using induction coils with the same orientation and essentially the same spatial location. Flat, air cored coils are used and are overlapped so as to have essentially zero mutual inductance between pairs.
Inventors
- 👤 Ivo Brcic
- 👤 Valentine Burda
- 👤 Ulrich W. Rentsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:57
CPC Classifications
G; G01; G01V; G01V3/00; G01V3/08; G01V3/10; G01V3/104; G01V3/105; G01V3/107
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
101 words
Electromagnetic exploration apparatus comprising means for simultaneously transmitting electromagnetic fields of three different frequencies, means for receiving transmitted electromagnetic fields of three different frequencies, at least one of said transmitting means and said receiving means including three air cored coils each lying in its own plane and having an axis perpendicular to its plane, said coils being mounted with their axes at least substantially parallel and with their planes closely spaced and at least substantially parallel, each coil being overlapped sufficiently with respect to the other two coils that the mutual inductance of said three coils is at least substantially zero.
Claim 2
Dependent Claim
101 words
Electromagnetic exploration apparatus comprising means for simultaneously transmitting electromagnetic fields of three different frequencies, means for receiving transmitted electromagnetic fields of three different frequencies, at least one of said transmitting means and said receiving means including three air cored coils each lying in its own plane and having an axis perpendicular to its plane, said coils being mounted with their axes at least substantially parallel and with their planes closely spaced and at least substantially parallel, each coil being overlapped sufficiently with respect to the other two coils that the mutual inductance of said three coils is at least substantially zero.
References Cited (Backward Citations)
FR960966A
Cited
US2451596A
Cited
US2557994A
Cited
US3012190A
Cited
US2642477A
Cited
US2955250A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-03 | 1984-08-04 | 1985-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-03 | 1988-08-04 | 1989-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-03 | 1992-08-04 | 1993-02-03 | $7700.00 | Window Closed / Lapsed |