Patent US3754155A successfully refreshed from Google Patents.
US3754155A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motor device whose circuit, comprises a thin layer of hard magnetic material
Assignee: RECH EN MATIERE SOC SOC CIV DE
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Filing: 1972-05-10
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Granted: 1973-08-21
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Expires: 1992-05-10
Abstract
Abstract Micro-motor with a homopolar structure, comprising a coil on the base on which a tubular core is fitted, a second tube fitted on a pole piece carrying a pinion, these two tubes being fitted one in the other, and a rotor comprising a bell with a thin cylindrical wall made of hard magnetic material.
Inventors
- 👤 C Oudet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:08
CPC Classifications
G; G04; G04C; G04C13/00; G04C13/08; G04C13/10; G04C13/11; G04C13/105; H; H02; H02K; H02K37/00; H02K37/10
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
181 words
Micro-motor of the type comprising a rotor with a cylindrical portion made of hard magnetic material and a stator comprising two polar pieces respectively polarized positively and negatively by the current which flows in a coil, these polarized pieces defining an air gap in which said cylindrical portion is placed and one at least of these two polar pieces is fitted with a set of substantially equispaced salient stator poles, said cylindrical portion being magnetized radially and being of such thickness that the ratio x of thE product Hc.L, Hc being the coercive field of said hard magnetic material and L the value of said thickness, to the product Br.e, Br being the remanent induction and e the dimension of the said air gap, is substantially below unity, characterized by the fact that the polar piece of the stator which carries the said set of stator poles is carried at the end of a tube made of soft magnetic material, this tube being fitted telescropically inside a further tube made of soft magnetic material which constitutes the core of the coil.
Claim 2
Dependent Claim
181 words
Micro-motor of the type comprising a rotor with a cylindrical portion made of hard magnetic material and a stator comprising two polar pieces respectively polarized positively and negatively by the current which flows in a coil, these polarized pieces defining an air gap in which said cylindrical portion is placed and one at least of these two polar pieces is fitted with a set of substantially equispaced salient stator poles, said cylindrical portion being magnetized radially and being of such thickness that the ratio x of thE product Hc.L, Hc being the coercive field of said hard magnetic material and L the value of said thickness, to the product Br.e, Br being the remanent induction and e the dimension of the said air gap, is substantially below unity, characterized by the fact that the polar piece of the stator which carries the said set of stator poles is carried at the end of a tube made of soft magnetic material, this tube being fitted telescropically inside a further tube made of soft magnetic material which constitutes the core of the coil.
Claim 3
Dependent Claim
63 words
Micro-motor in accordance with claim 1, further comprising a base on which said core is fixedly mounted, the said tube forming a magnetic joint with the said set of stator poles and the said core forming a further magnetic joint with the said base, the said magnetic joints being of the type having a negligibly small reluctance resulting from annealing at high temperature.
Claim 4
Dependent Claim
45 words
Micro-motor in accordance with claim 1, characterized by a polarized system consisting of an annular permanent magnet fixed above said cylindrical portion and by a toothed wheel made of soft magnetic material wedged on the shaft of the rotor, facing said magnet which encircles it.
Claim 5
Dependent Claim
36 words
Micro-motor in accordance with claim 3, chaaracterized in that said magnet comprises alternate poles equal in number to the number of teeth on said wheel and to the number of stator poles of the said set.
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) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |