Patent US3917997A successfully refreshed from Google Patents.
US3917997A
Expired / Lapsed
US
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Magnetic flux closure member for an angular velocity sensing device
Assignee: General Research Inc
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Filing: 1974-09-20
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Granted: 1975-11-04
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Expires: 1994-09-20
Abstract
Abstract A sensing device with improved sensitivity for sensing the velocity of a rotating magnetizable wheel is disclosed. The sensing device utilizes two closed-loop magnetic cores and four inductive windings which are interconnected to form a four-arm active bridge circuit, all arms of which are affected by the rotating wheel. A permanent magnet biases the two magnetic cores to partial saturation and also supplies magnetic flux to the rotating wheel. In one version, two windings are wound around each of the cores. In another version, one winding is wound around each of the cores; and a separate magnetic member that provides a return path for the bias magnetic flux that passes through the cores has two apertures at its ends and each of the other two windings is wound through one of these apertures.
Inventors
- 👤 Edward F Sidor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:29
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/321; B60T8/329; G; G01; G01P; G01P3/00; G01P3/42; G01P3/44; G01P3/48; G01P3/481; G01P3/488
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
334 words
In a velocity sensing device for sensing the velocity of a rotating member having a plurality of projections of substantially equal width separated by spaces of substantially equal width on its periphery with said projections being capable of conducting magnetic flux to create a time-varying magnetic field comprising a four-arm, four-terminal active bridge circuit sensing means that comprises a pair of magnetic cores positioned adjacent the periphery of said rotating member, a first winding on one of said cores, a second winding on the other of said cores, third and fourth windings which are interconnected with each other and with said first and said second windings to form said bridge circuit, the center line of a first one of said cores being aligned with the center line of a first one of said projections when the center line of the second one of said cores is approximately aligned with the center line of the space between said first one of said projections and the next adjacent projection, and excitation generator means coupled to supply a carrier signal across two terminals of said bridge circuit, so as to provide an output signal across the other two terminals of said bridge circuit; the improvement comprising a magnetically permeable flux closure member positioned adjacent said cores and having first and second legs and a section that joins said legs, said first leg having a first aperture therein and said second leg having a second aperture therein constructed so as to receive said third winding through said first aperture and said fourth winding through said second aperture and so that the center lines of said legs are spaced such that the center line of said first leg is aligned with the center line of the projection that precedes said first one of said projections when the center line of said second leg is approximately aligned with the center line of the space that succeeds said space between said first one of said projections and said next adjacent projection.
Claim 2
Dependent Claim
334 words
In a velocity sensing device for sensing the velocity of a rotating member having a plurality of projections of substantially equal width separated by spaces of substantially equal width on its periphery with said projections being capable of conducting magnetic flux to create a time-varying magnetic field comprising a four-arm, four-terminal active bridge circuit sensing means that comprises a pair of magnetic cores positioned adjacent the periphery of said rotating member, a first winding on one of said cores, a second winding on the other of said cores, third and fourth windings which are interconnected with each other and with said first and said second windings to form said bridge circuit, the center line of a first one of said cores being aligned with the center line of a first one of said projections when the center line of the second one of said cores is approximately aligned with the center line of the space between said first one of said projections and the next adjacent projection, and excitation generator means coupled to supply a carrier signal across two terminals of said bridge circuit, so as to provide an output signal across the other two terminals of said bridge circuit; the improvement comprising a magnetically permeable flux closure member positioned adjacent said cores and having first and second legs and a section that joins said legs, said first leg having a first aperture therein and said second leg having a second aperture therein constructed so as to receive said third winding through said first aperture and said fourth winding through said second aperture and so that the center lines of said legs are spaced such that the center line of said first leg is aligned with the center line of the projection that precedes said first one of said projections when the center line of said second leg is approximately aligned with the center line of the space that succeeds said space between said first one of said projections and said next adjacent projection.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |