Patent US3118260A successfully refreshed from Google Patents.
US3586964A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inductive transducers
Assignee: Associated Engineering Ltd
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Filing: 1969-04-30
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Granted: 1971-06-22
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Expires: 1989-04-30
Abstract
Abstract The present invention relates to inductive transducers and discloses constructions of such transducers having two concentrically arranged coil and core assemblies wherein the cores are formed of ferromagnetic material and have their ends terminating at the working face of the transducer. In operation, the coils of the transducer may be connected in the opposed arms of a bridge circuit, thereby producing a substantially linear output from the bridge circuit.
Inventors
- 👤 Heinrich Strauch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:59
CPC Classifications
H; H01; H01F; H01F37/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
122 words
An inductive transducer comprising a first ferromagnetic core, a first coil extending around said core, part of said first core being turned back round the outside of said first coil, both ends of said first core terminating in a plane forming the working face of the transducer, a second ferromagnetic core disposed around the periphery of said first coil, a second coil extending around said second core, part of said second core being turned back round the outside of said second coil, both ends of said second core terminating at said working face, the spacing between the two ends of one of said cores being substantially greater than the spacing between the two ends of the wires of the other said core.
Claim 2
Dependent Claim
122 words
An inductive transducer comprising a first ferromagnetic core, a first coil extending around said core, part of said first core being turned back round the outside of said first coil, both ends of said first core terminating in a plane forming the working face of the transducer, a second ferromagnetic core disposed around the periphery of said first coil, a second coil extending around said second core, part of said second core being turned back round the outside of said second coil, both ends of said second core terminating at said working face, the spacing between the two ends of one of said cores being substantially greater than the spacing between the two ends of the wires of the other said core.
Claim 3
Dependent Claim
37 words
A transducer as claimed in claim 1, wherein said first and second cores each include a plurality of ferromagnetic wires having part of their length turned back round the outside of the first and second coils respectively.
Claim 4
Dependent Claim
21 words
A transducer as claimed in claim 1, including a screen of ferromagnetic material arranged between the two coil and core assemblies.
Claim 5
Dependent Claim
39 words
A transducer as claimed in claim 1, wherein the first coil is wound between two portions of insulating material surrounding the first core, and the second coil is wound between two portions of insulating material surrounding the second core.
Claim 6
Dependent Claim
29 words
A transducer as claimed in claim 2, wherein the first and second cores are formed from iron wires and the first and second coils are wound from copper wires.
Claim 7
Dependent Claim
68 words
A transducer as claimed in claim 1, wherein the second coil has approximately the same axial extent as the first coil and also has approximately the same number of turns as the first coil and wherein, in order to have the same total resistance as the first coil, said second coil is wound of a wire having a lower specific resistance than the wire forming the first coil.
Claim 8
Dependent Claim
48 words
A transducer as claimed in claim 1, having a substantially circular cross section to the axial direction of said cores and wherein the radial spacing between the two ends of the first core is substantially greater than the radial spacing between the two ends of the second core.
Claim 9
Dependent Claim
45 words
A transducer as claimed in claim 7, wherein the first and second cores each include a plurality of ferromagnetic wires, and the folded back portion of the wires of said first and second cores are substantially equally spaced in a circumferential direction around the transducer.
Claim 10
Dependent Claim
24 words
A transducer as claimed in claim 1, wherein the coil and core assemblies are encapsulated in an insulating material, such an an epoxy resin.
Claim 11
Dependent Claim
77 words
A circuit arrangement including an inductive transducer as claimed in claim 1, wherein said first and second coils are connected to form the opposed arms of a bridge circuit, so that the effect of a change of inductance occurring in one of said coils is at least partially compensated by the effect of a change of inductance in the same sense occurring in the other of said coils, thereby producing a substantially linear output from the bridge.
Claim 12
Dependent Claim
78 words
An arrangement as claimed in claim 10, wherein said first and second coils are connected respectively in first and second arms of an AC bridge circuit, means for deriving an output from across one end of said first and second arms, means connecting the other end of said first and second arms together and to earth potential, and an AC input connected across the common point of the third and fourth arms of the bridge circuit and earth.
Claim 13
Dependent Claim
39 words
An arrangement as claimed in claim 11, in which the AC input is a high frequency carrier wave and the output of the bridge is fed through a synchronous detector and a filter to a recorder or an oscilloscope.
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) | 1974-06-21 | 1974-12-21 | 1975-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-21 | 1978-12-21 | 1979-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-21 | 1982-12-21 | 1983-06-22 | $7700.00 | Window Closed / Lapsed |