Patent US4189699A successfully refreshed from Google Patents.
US4189699A
Expired / Lapsed
US
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Limited-rotation motor with integral displacement transducer
Assignee: STOCKER & YALE Inc A MASSACHUSETTS Corp
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Filing: 1978-05-17
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Granted: 1980-02-19
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Expires: 1998-05-17
Abstract
Abstract The armature of a limited-rotation motor which rotates about an axis relative to a stator is extended axially beyond the stator between arcuate, non-magnetic capacitor plates disposed in a cylindrical array coaxial with the rotation axis. The capacitor plates are connected in a bridge circuit whose output is a selected function of armature displacement. The capacitor plates are installed at the end of the motor stator during assembly of the motor as tines of a unitary slotted bushing that is reamed simultaneously with the motor stator, following which the bushing is circumferentially cut to electrically isolate the bushing tines to form the individual plates.
Inventors
- 👤 Edward F. Burke, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 11:34
CPC Classifications
H; H01; H01G; H01G5/00; H01G5/01; H01G5/013; H01F; H01F29/00; H01F29/14; H01F29/143; H01F7/00; H01F7/06; H01F7/08; H01F7/14; H01F7/145; H02; H02K; H02K26/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
171 words
A limited rotation motor of the type having an array of pole pieces defining a cylindrical passage and an armature rotatively mounted coaxially in the passage and biased toward a reference position, the improvement comprising A. a bushing made of an electrically conductive non-ferromagnetic material having an inside diameter that is equal to the diameter of said passage and positioned coaxially with the passage so that the bushing forms an extension of said passage, B. means defining lengthwise slits in the bushing so as to form at least one pair of tines, C. means defining a circular cut in the bushing that separates the tines from each other and from the bushing collar so as to electrically isolate the tines, and D. an integral extension on the armature that projects beyond the pole pieces through the bushing so that the opposing surfaces of the armature and the tines form an armature displacement transducer whereby the differential capacitance between the armature surfaces and the tines provides an indication of armature angular displacement.
Claim 2
Dependent Claim
171 words
A limited rotation motor of the type having an array of pole pieces defining a cylindrical passage and an armature rotatively mounted coaxially in the passage and biased toward a reference position, the improvement comprising A. a bushing made of an electrically conductive non-ferromagnetic material having an inside diameter that is equal to the diameter of said passage and positioned coaxially with the passage so that the bushing forms an extension of said passage, B. means defining lengthwise slits in the bushing so as to form at least one pair of tines, C. means defining a circular cut in the bushing that separates the tines from each other and from the bushing collar so as to electrically isolate the tines, and D. an integral extension on the armature that projects beyond the pole pieces through the bushing so that the opposing surfaces of the armature and the tines form an armature displacement transducer whereby the differential capacitance between the armature surfaces and the tines provides an indication of armature angular displacement.
Claim 3
Dependent Claim
88 words
The motor defined in claim 1 and further including A. a shaft projecting axially from one end of the armature, B. means for journalling the shaft in the bushing collar beyond the bushing tines, C. an electrically conductive torsion spring connected to the armature and extending axially from the armature through the shaft and through the bushing collar, D. means for conductively anchoring the outer end of the spring to the bushing, and E. means for establishing an electrical connection to the armature by way of the spring.
Claim 4
Dependent Claim
35 words
The motor defined in claim 1 and further including A. a shaft projecting axially from one end of the armature, and B. means for journalling the shaft in the bushing collar beyond the bushing tines.
Claim 5
Dependent Claim
43 words
The motor defined in claim 3 and further including A. a torsion spring connected to the armature and extending axially from the armature through the shaft and through the bushing collar, and B. means for rotatively anchoring the outer end of the spring.
Claim 6
Dependent Claim
16 words
The motor defined in claim 4 wherein the torsion spring and anchoring means are electrically conductive.
References Cited (Backward Citations)
US2426199A
Cited
US3337789A
Cited
USRE26749E
Cited
US3517282A
Cited
US3652955A
Cited
US4110879A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-02-18 | 1983-08-20 | 1984-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-18 | 1987-08-20 | 1988-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-18 | 1991-08-20 | 1992-02-19 | $7700.00 | Window Closed / Lapsed |