Patent US3700942A successfully refreshed from Google Patents.
US3700942A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-starting synchronous motors
Assignee: Individual
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Filing: 1971-02-03
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Granted: 1972-10-24
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Expires: 1991-02-03
Abstract
Abstract A conductive metal disc is mounted on a shaft. A number of magnets are mounted on said disc in a cicle, equidistant from each other, equidistant from said shaft and a distance in from the edge of the disc. This is the rotor. The stator comprises a number of coils mounted on U-shaped iron cores. The cores are positioned, open ends inwards, towards the shaft, overlapping the edge of the disc, circumferentially about the rotor. Cores are directed at equal angles , from 15* to 90* to the radii of the disc. As flux propagation is in relatively narrow bands at an angle other than radial to the shaft, the conductor is repulsed and turns. Synchronization occurs at a speed related to number of driving poles and rotating fields. Alternately, PMs may be replaced by coils powered by DC taken from slips rings; by induced AC power converted to DC by rectifiers connected to the coils and mounted on the rotor, and by shorted turns on said rotating poles.
Inventors
- 👤 Max Alth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:56
CPC Classifications
H; H02; H02K; H02K19/00; H02K19/02; H02K19/10; H02K21/00; H02K21/12; H02K21/24
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
120 words
A self-starting synchronous motor comprising an electrical conductive means generally circular in outline and fastened to a shaft means orthogonal to its center, a plurality of small permanent magnets piercing said conductive means, said magnets generally positioned a distance inward from edge of said conductive means and generally equidistant from each other and generally circular aboutsaid shaft means; said magnets cooperating with the flux to produce synchronization; a plurality of AC-flux generating means comprising a plurality of electrical coils mounted on a plurality of U-shaped cores of magnetically permeable material, open ends of said U-shapes passing above and below said conductive means, all said arms generally parallel and directed at an angle generally oblique to radii of said conductive means.
Claim 2
Dependent Claim
120 words
A self-starting synchronous motor comprising an electrical conductive means generally circular in outline and fastened to a shaft means orthogonal to its center, a plurality of small permanent magnets piercing said conductive means, said magnets generally positioned a distance inward from edge of said conductive means and generally equidistant from each other and generally circular aboutsaid shaft means; said magnets cooperating with the flux to produce synchronization; a plurality of AC-flux generating means comprising a plurality of electrical coils mounted on a plurality of U-shaped cores of magnetically permeable material, open ends of said U-shapes passing above and below said conductive means, all said arms generally parallel and directed at an angle generally oblique to radii of said conductive means.
Claim 3
Dependent Claim
80 words
A device as claimed in claim 1, said flux generating means to comprise an annulus of magnetically permeable material, said annulus to have a U-shaped cross section the edges of which are deeply notched to form a plurality of pole arm pairs, all generally parallel, all pointing generally inward towards the center of said conductive means at an oblique angle, said arm pairs passing above and below said conductive means, in addition an electric coil of wire within said annulus.
Claim 4
Dependent Claim
40 words
A device as claimed in claim 1, said magnetic pole means to comprise a single piece of permanently magnetized material, generally circular in shape, generally flat with edges cut into a plurality of small arcs, each an individual magnetic pole.
Claim 5
Dependent Claim
65 words
A device as claimed in claim 1, said magnetic pole means to comprise a pair of hubs of magnetically permeable material, pierced to accept said shaft means, circumferentially notched to form a plurality of magnetic poles, said poles to be within the influence of said alternating current magnetic pole means, in addition a coil positioned axially between said hubs, said coils connected to slip rings.
Claim 6
Dependent Claim
97 words
A device as claimed in claim 1, having an electrically conducTive means generally circular in outline and fastened to a shaft means orthogonal to its center and having a plurality of permanent magnets piercing said conductive means, said magnets generally positioned a distance from each other and generally circular about said shaft means, in addition having a plurality of magnetically permeable cores generally positioned circularly about said shaft and a distance inward from the edge of said conductive means, said permeable magnetic cores disposed to cooperate in conjunction with said permanent magnets and said AC flux means.
Claim 7
Dependent Claim
66 words
A device as claimed in claim 1, said magnetic pole means to comprise a pair of hubs of magnetically permeable material, pierced to accept said shaft means, circumferentially notched to form a plurality of magnetic poles, said poles to be within the influence of said alternating current magnetic pole means, in addition a coil positioned axially between said hub, said coil connected to a rectifying means.
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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) | 1975-10-24 | 1976-04-24 | 1976-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-24 | 1980-04-24 | 1980-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-24 | 1984-04-24 | 1984-10-24 | $7700.00 | Window Closed / Lapsed |