US3573693A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multinull rotary variable differential transformer
Assignee: Pickering Controls Inc
•
Filing: 1969-03-06
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Granted: 1971-04-06
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Expires: 1989-03-06
Abstract
Abstract A rotary variable differential transformer having a plurality of null positions within 360 * of mechanical rotation having each of two primary windings associated with a toothed magnetic ring, with the rings identical but angularly displaced and the primary windings wound in series opposition, and a secondary winding associated with a toothed rotor being rotatable with respect to the toothed rings whereby the angular position of the rotor determines the voltage in the secondary winding from null to peak output.
Inventors
- 👤 Jacob Chass
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:51
CPC Classifications
H; H01; H01F; H01F29/00; H01F29/08; H01F29/10; H01F38/00; H01F38/18
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
153 words
A rotary variable differential transformer including in combination a magnetic casing, first, second and third coils wound on a bobbin of nonconducting, nonmagnetic material within said casing and insulated therefrom, said coils being longitudinally displaced with said third coil between said first and second coils, said first and second coils providing a first winding, said third coil providing a second winding, first and second rings of magnetic teeth supported by said casing respectively within the magnetic fields of said first and second coils, said first magnetic teeth being angularly displaced from said second magnetic teeth, a rotor member rotatably supported by said casing, a third ring of magnetic teeth provided on said rotor within the magnetic field of said third coil, and means for energizing one of said windings whereby the remainder of said windings is energized in accordance with the relative position of said third teeth and said first and second teeth.
Claim 2
Dependent Claim
153 words
A rotary variable differential transformer including in combination a magnetic casing, first, second and third coils wound on a bobbin of nonconducting, nonmagnetic material within said casing and insulated therefrom, said coils being longitudinally displaced with said third coil between said first and second coils, said first and second coils providing a first winding, said third coil providing a second winding, first and second rings of magnetic teeth supported by said casing respectively within the magnetic fields of said first and second coils, said first magnetic teeth being angularly displaced from said second magnetic teeth, a rotor member rotatably supported by said casing, a third ring of magnetic teeth provided on said rotor within the magnetic field of said third coil, and means for energizing one of said windings whereby the remainder of said windings is energized in accordance with the relative position of said third teeth and said first and second teeth.
Claim 3
Dependent Claim
22 words
A rotary variable differential transformer in accordance with claim 1 in which said first and second coils are connected in series opposition.
Claim 4
Dependent Claim
67 words
A rotary variable differential transformer in accordance with claim 1 in which a bore is formed in said casing, said first and second rings of magnetic teeth are supported within said bore and said third ring of magnetic teeth is rotatably supported within said bore with said first and second rings disposed at either end of said bore radially inwardly of said first and second coils respectively.
Claim 5
Dependent Claim
32 words
A rotary variable differential transformer in accordance with claim 3 in which there are equal numbers of said first and second magnetic teeth of identical dimension but angularly displaced one tooth width.
Claim 6
Dependent Claim
64 words
A rotary variable differential transformer in accordance with claim 4 in which said third ring of magnetic teeth includes teeth equal in number to the teeth on one of said first and second rings and each of said third teeth has the same width as each of said first and second teeth with the gaps between teeth equal to the width of a tooth.
References Cited (Backward Citations)
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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) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |