Patent US2239738A successfully refreshed from Google Patents.
Patent US4296486A successfully refreshed from Google Patents.
US4296486A
Expired / Lapsed
US
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Shielded electromagnetic acoustic transducers
Assignee: Boeing North American Inc
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Filing: 1980-01-24
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Granted: 1981-10-20
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Expires: 2000-01-24
Abstract
Abstract Disclosed is an electromagnetic acoustic transducer, including a source of magnetic flux for establishing a static magnetic field, an electrical conductor for conducting an alternating current in the static magnetic field, and an electrically conductive, nonmagnetic shield disposed between the source of magnetic flux and the conductor.
Inventors
- 👤 Carmine F. Vasile
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:35
CPC Classifications
H; H04; H04R; H04R9/00; H04R9/02; H04R9/04; H04R9/046; H04R9/047; B; B06; B06B; B06B1/00; B06B1/02; B06B1/04
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
74 words
An electromagnetic acoustic transducer for use near a surface of an electrically conductive object, comprising: a source of magnetic flux for establishing a static magnetic field in said object; an electrical conductor disposed between said source of magnetic flux and said surface and proximate to said surface for conducting an alternating current in said static magnetic field; and a thin, electrically conductive, nonmagnetic shield disposed between said source of magnetic flux and said conductor.
Claim 2
Dependent Claim
74 words
An electromagnetic acoustic transducer for use near a surface of an electrically conductive object, comprising: a source of magnetic flux for establishing a static magnetic field in said object; an electrical conductor disposed between said source of magnetic flux and said surface and proximate to said surface for conducting an alternating current in said static magnetic field; and a thin, electrically conductive, nonmagnetic shield disposed between said source of magnetic flux and said conductor.
Claim 3
Dependent Claim
13 words
The transducer of claim 1, wherein said shield comprises a thin metallic sheet.
Claim 4
Dependent Claim
13 words
The transducer of claim 2, wherein said shield further comprises a copper sheet.
Claim 5
Dependent Claim
23 words
The transducer of claim 3, wherein said shield is disposed in contact with said source of magnetic flux and spaced from said conductor.
Claim 6
Dependent Claim
20 words
The transducer of claim 1, wherein said source of magnetic flux further comprises a row of alternately oriented permanent magnets.
Claim 7
Dependent Claim
15 words
The transducer of claim 1, wherein said source of magnetic flux further comprises an electromagnet.
Claim 8
Dependent Claim
88 words
An electromagnetic acoustic transducer for use near a surface of an electrically conductive object, comprising: a row of alternately oriented permanent magnets for establishing a static magnetic field in said object; an electrical conductor disposed between said row of magnets and said surface and proximate to said surface for conducting an alternating current in said static magnetic field; and a thin metallic shield disposed between said row of magnets and said conductor such that said shield contacts said row of magnets and is spaced slightly from said conductor.
Claim 9
Dependent Claim
88 words
An electromagnetic acoustic transducer for use near a surface of an electrically conductive object, comprising: a row of alternately oriented permanent magnets for establishing a static magnetic field in said object; an electrical conductor disposed between said row of magnets and said surface and proximate to said surface for conducting an alternating current in said static magnetic field; and a thin metallic shield disposed between said row of magnets and said conductor such that said shield contacts said row of magnets and is spaced slightly from said conductor.
Claim 10
Dependent Claim
77 words
An electromagnetic acoustic transducer for use near a surface of an electrically conductive object, comprising: an electromagnet for establishing a static magnetic field in said object; an electrical conductor disposed between said electromagnet and said surface and proximate to said surface for conducting an alternating current in said static magnetic field; and a thin metallic shield disposed between said electromagnet and said conductor such that said shield contacts said electromagnet and is spaced slightly from said conductor.
Claim 11
Dependent Claim
77 words
An electromagnetic acoustic transducer for use near a surface of an electrically conductive object, comprising: an electromagnet for establishing a static magnetic field in said object; an electrical conductor disposed between said electromagnet and said surface and proximate to said surface for conducting an alternating current in said static magnetic field; and a thin metallic shield disposed between said electromagnet and said conductor such that said shield contacts said electromagnet and is spaced slightly from said conductor.
Claim 12
Dependent Claim
79 words
An improved electromagnetic acoustic transducer for use near a surface of an electrically conductive object, including a source of magnetic flux for establishing a static magnetic field in said object and an electrical conductor disposed between said source of magnetic flux and said surface and proximate to said surface for conducting an alternating current in said static magnetic field, wherein the improvement comprises a thin, electrically conductive, nonmagnetic shield disposed between said source of magnetic flux and said conductor.
Claim 13
Dependent Claim
79 words
An improved electromagnetic acoustic transducer for use near a surface of an electrically conductive object, including a source of magnetic flux for establishing a static magnetic field in said object and an electrical conductor disposed between said source of magnetic flux and said surface and proximate to said surface for conducting an alternating current in said static magnetic field, wherein the improvement comprises a thin, electrically conductive, nonmagnetic shield disposed between said source of magnetic flux and said conductor.
Claim 14
Dependent Claim
14 words
The transducer of claim 9, wherein said shield further comprises a thin metallic sheet.
Claim 15
Dependent Claim
67 words
An electromagnetic acoustic transducer for use near a surface of an electrically conductive object, comprising: means for establishing a static magnetic field in said object; means disposed between said magnetic field means and said surface and proximate to said surface for conducting an alternating current through said magnetic field; and a thin, electrically conductive, nonmagnetic shield disposed between said static magnetic field means and said conducting means.
Claim 16
Dependent Claim
67 words
An electromagnetic acoustic transducer for use near a surface of an electrically conductive object, comprising: means for establishing a static magnetic field in said object; means disposed between said magnetic field means and said surface and proximate to said surface for conducting an alternating current through said magnetic field; and a thin, electrically conductive, nonmagnetic shield disposed between said static magnetic field means and said conducting means.
Claim 17
Dependent Claim
82 words
An improved method for generating an ultrasonic wave in an electrically conductive object, including the steps of positioning a source of magnetic flux to establish a static magnetic field in the object, positioning an electrical conductor between the source of magnetic flux and the surface and proximate to the surface, and connecting the conductor to an alternating current source, wherein the improvement comprises the step of positioning a thin, electrically conductive, nonmagnetic shield between the source of magnetic flux and the conductor.
Claim 18
Dependent Claim
82 words
An improved method for generating an ultrasonic wave in an electrically conductive object, including the steps of positioning a source of magnetic flux to establish a static magnetic field in the object, positioning an electrical conductor between the source of magnetic flux and the surface and proximate to the surface, and connecting the conductor to an alternating current source, wherein the improvement comprises the step of positioning a thin, electrically conductive, nonmagnetic shield between the source of magnetic flux and the conductor.
Claim 19
Dependent Claim
85 words
An improved method for detecting an ultrasonic wave in an electrically conductive object, including the steps of positioning a source of magnetic flux to establish a static magnetic field in the object, positioning an electrical conductor between the source of magnetic flux and the surface and proximate to the surface, and detecting the signal induced in the conductor by the ultrasonic wave, wherein the improvement comprises the step of positioning a thin, electrically conductive, nonmagnetic shield between the source of magnetic flux and the conductor.
Claim 20
Dependent Claim
85 words
An improved method for detecting an ultrasonic wave in an electrically conductive object, including the steps of positioning a source of magnetic flux to establish a static magnetic field in the object, positioning an electrical conductor between the source of magnetic flux and the surface and proximate to the surface, and detecting the signal induced in the conductor by the ultrasonic wave, wherein the improvement comprises the step of positioning a thin, electrically conductive, nonmagnetic shield between the source of magnetic flux and the conductor.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-10-19 | 1985-04-20 | 1985-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-19 | 1989-04-20 | 1989-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-19 | 1993-04-20 | 1993-10-20 | $7700.00 | Window Closed / Lapsed |