US3665381A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Movable coil bi-gradient transducer
Assignee: United States Department of the Navy
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Filing: 1971-01-25
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Granted: 1972-05-23
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Expires: 1991-01-25
Abstract
Abstract A movable coil bi-gradient transducer responsive to the angle of arrival of a given sound wave. An orthogonal array of four coils are embedded in a flat non-magnetic disk and suspended in the air gap of an annular magnetic unit by four thin rods. Opposite coils are wired in series with only their outer halves normally in the annular field of flux whereby the combined voltages of the coils is equal to zero. A cylindrical acoustically transparent boot, filled with silicon oil, encases the magnetic unit and suspended disk. Acoustic pressure waves arriving at the outside of the boot are transmitted through the silicone oil causing lateral displacement of the four coils in the same direction as the pressure wave to produce electrical output signals at respective pairs of coils indicative of the sine and cosine functions of the arrival angle of the pressure wave.
Inventors
- 👤 Benjamin B Bauer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:13
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/32; H04R1/40; H04R1/406; H04R11/00; H04R11/04
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
123 words
A bi-gradient electroacoustic transducer comprising: an acoustically transparent cylindrical housing sealingly enclosed at both ends; magnet means supported witHin and slidable along the length of said housing and forming a gap with an annular field of flux parallel to the length of said housing; a flat element having an annular matrix of four orthogonally positioned embedded coils, opposite ones of said coils being wired in series, and the outer halves of said coils being radially coextensive with the annular field of flux; four rods normally suspending said element coaxially in said gap and electrically connected to respective ones of said coils for transmitting signals therefrom; and a fluid completely filling the interstices formed by said magnet means, element and rods in said housing.
Claim 2
Dependent Claim
123 words
A bi-gradient electroacoustic transducer comprising: an acoustically transparent cylindrical housing sealingly enclosed at both ends; magnet means supported witHin and slidable along the length of said housing and forming a gap with an annular field of flux parallel to the length of said housing; a flat element having an annular matrix of four orthogonally positioned embedded coils, opposite ones of said coils being wired in series, and the outer halves of said coils being radially coextensive with the annular field of flux; four rods normally suspending said element coaxially in said gap and electrically connected to respective ones of said coils for transmitting signals therefrom; and a fluid completely filling the interstices formed by said magnet means, element and rods in said housing.
Claim 3
Dependent Claim
41 words
A transducer according to claim 1, further comprising: said magnet means including a cylindrical outer cage, and upper and lower end plates affixed to the ends of said cage, the gap being formed within said cage and between said end plates.
Claim 4
Dependent Claim
29 words
A transducer according to claim 2, further comprising: said magnet means including a magnet polarized along the length of said housing affixed at one pole to the upper plate.
Claim 5
Dependent Claim
62 words
A transducer according to claim 3, further comprising: said magnet means including an upper pole piece affixed to the other pole of said magnet and forming an annular planar surface at the gap, and a lower pole piece affixed to said lower plate and forming an annular planar surface at the gap and confronting said other surface in parallel and spaced relationship.
Claim 6
Dependent Claim
32 words
A transducer according to claim 4, further comprising: said upper and lower plates of said magnet means having openings formed therethrough for establishing free fluid communication between the ends of said housing.
Claim 7
Dependent Claim
40 words
A transducer according to claim 5, further comprising: compliant means interposed respectively between said upper and lower plates and the confronting ends of said housing for resiliently positioning said magnet means in a position intermediate the length of said housing.
Claim 8
Dependent Claim
30 words
A transducer according to claim 6, further comprising: said rods having an elasticity for uniform deflection along their lengths with lateral displacement of said element relative to said magnet means.
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) | 1975-05-23 | 1975-11-22 | 1976-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-23 | 1979-11-22 | 1980-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-23 | 1983-11-22 | 1984-05-23 | $7700.00 | Window Closed / Lapsed |