US3882436A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differential transformer
Assignee: Pickering Controls Inc
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Filing: 1974-08-05
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Granted: 1975-05-06
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Expires: 1994-08-05
Abstract
Abstract A rotary variable differential transformer is provided. The transformer comprises an elongated bobbin formed of nonmagnetic, non-conductive material about which a primary coil is circumferentially wound. A secondary coil adjacent to the primary coil is also wound about the bobbin extending longitudinally from a first position proximal the primary coil to a second position distal the primary coil and thereafter returning to the first position along a substantially axial line. A core is disposed for rotation within the bobbin. The core carries an elongated magnetic member which serves to couple the primary and secondary coils, the position of coupling being determined by the position of the core. The output of the differential transformer may be linear (or have some other desired shape) over a relatively wide angle of rotation of the core.
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
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
97 words
A rotary variable differential transformer comprising: an elongated bobbin forMed of non-magnetic, non-conductive material; a primary coil wound circumferentially about said bobbin; a secondary coil adjacent said primary coil wound circumferentially about said bobbin and extending longitudinally from a first position proximal said primary coil to a second position distal said primary coil and thereafter returning to said first position; a rotor assembly disposed for rotation within said bobbin; and an elongated ferromagnetic core secured to said rotor assembly for rotation therewith, said core extending longitudinally between said primary and secondary coils and providing magnetic coupling therebetween.
Claim 2
Dependent Claim
97 words
A rotary variable differential transformer comprising: an elongated bobbin forMed of non-magnetic, non-conductive material; a primary coil wound circumferentially about said bobbin; a secondary coil adjacent said primary coil wound circumferentially about said bobbin and extending longitudinally from a first position proximal said primary coil to a second position distal said primary coil and thereafter returning to said first position; a rotor assembly disposed for rotation within said bobbin; and an elongated ferromagnetic core secured to said rotor assembly for rotation therewith, said core extending longitudinally between said primary and secondary coils and providing magnetic coupling therebetween.
Claim 3
Dependent Claim
16 words
The transformer in accordance with claim 1 further comprising a ferromagnetic shell disposed about said bobbin.
Claim 4
Dependent Claim
51 words
The transformer in accordance with claim 1 further comprising a second secondary coil disposed adjacent said primary coil opposite said first secondary coil, said second secondary coil extending longitudinally from a first position proximal said primary coil to a second position distal said primary coil and thereafter returning to first position.
Claim 5
Dependent Claim
33 words
The transformer in accordance with claim 1 wherein said bobbin is cylindrical and said secondary coil first and second positions are on a line substantially parallel to the axis of said cylindrical bobbin.
Claim 6
Dependent Claim
54 words
The transformer in accordance with claim 3 wherein said bobbin is cylindrical; said secondary coil first and second positions are on a line substantially parallel to the axis of said cylindrical bobbin and said second secondary coil first and second positions are on a line substantially parallel to the axis of said cylindrical bobbin.
Claim 7
Dependent Claim
42 words
The transformer in accordance with claim 5 wherein said secondary coil first and second positions and said second secondary coil first and second positions are all on a common line, said line being substantially parallel to the axis of said cylindrical bobbin.
Claim 8
Dependent Claim
25 words
The transformer in accordance with claim 6 wherein said secondary coil and second secondary coil have identical windings and are connected in bucking series relationship.
Claim 9
Dependent Claim
33 words
The transformer in accordance with claim 7 wherein said core comprises a non-magnetic cylindrical member and said ferromagnetic core is secured at the periphery of said rotor assembly closely adjacent to said bobbin.
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) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |