US4544904A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite magnet and magnetic circuit
Assignee: Individual
•
Filing: 1984-02-24
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Granted: 1985-10-01
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Expires: 2004-02-24
Abstract
Abstract Disclosed herein is a composite permanent magnet and a circuit which employs a plurality of such magnets. The composite magnet combines discrete sections of a first magnet material with at least one discrete section of a second magnetic material. The first material has a high residual magnetic strength and a moderate energy product. The second material is many times more expensive than the first material and is characterized by a high residual magnetic strength and a high energy product. Also disclosed is a circuit combining a plurality of such composite magnets. The circuit combines the above magnets in such a way that there is a reduction in magnetic leakage in the circuit.
Inventors
- 👤 Kishore Tarachand
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:15
CPC Classifications
H; H01; H01F; H01F7/00; H01F7/02; H01F7/0205; H01F7/021
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
104 words
A composite magnet comprising: at least a first discrete section of a first magnetic material, having a high residual magnetic strength, and an energy product greater than 3 million G-Oe; a second discrete section of a second magnetic material comprising at least 1/3 of the composite and dissimilar to the first material, having a high residual magnetic strength, at least a high energy product greater than 15 million G-Oe; an intrinsic coercive force (H ci ) greater than 3000 Oe, the first material in contact with the second and the first material surrounding at least 30% of the surface area of the second material.
Claim 2
Dependent Claim
104 words
A composite magnet comprising: at least a first discrete section of a first magnetic material, having a high residual magnetic strength, and an energy product greater than 3 million G-Oe; a second discrete section of a second magnetic material comprising at least 1/3 of the composite and dissimilar to the first material, having a high residual magnetic strength, at least a high energy product greater than 15 million G-Oe; an intrinsic coercive force (H ci ) greater than 3000 Oe, the first material in contact with the second and the first material surrounding at least 30% of the surface area of the second material.
Claim 3
Dependent Claim
31 words
A composite magnet as set forth in claim 1, wherein there are at least 2 discrete first sections and the first material surrounds at least 2 sides of the second material.
Claim 4
Dependent Claim
36 words
A composite magnet as set forth in claim 1, wherein the energy product of the first material is between 3-12 million G-Oe and the energy product of the second material is greater than 17 million G-Oe.
Claim 5
Dependent Claim
27 words
A composite magnet as set forth in claim 3 wherein the second magnetic material is from the family of elements known as rare earth transition metals (RE-TM).
Claim 6
Dependent Claim
23 words
A composite magnet as set forth in claim 4 wherein the first magnetic material is barrium ferrite oxide (BaFe 2 O 3 ).
Claim 7
Dependent Claim
19 words
A composite magnet as set forth in claim 4 wherein the first magnetic material is aluminum nickel cobalt (A1NiCo).
Claim 8
Dependent Claim
100 words
A magnetic circuit, comprising: a plurality of composite magnets as set forth in claim 1; the magnets being located adjacent one another and coaxially aligned; the magnets being spaced apart by a fixed air gap, such that the first material of one magnet is directly adjacent the first material of another magnet; each adjacent magnet being different in polarity thereby creating alternating north and south poles; whereby strong lines of flux are created across the air gap by the directly adjacent first materials causing the lines of flux of adjacent second materials to be bowed away from the air gap.
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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) | 1988-09-30 | 1989-04-01 | 1989-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-30 | 1993-04-01 | 1993-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-30 | 1997-04-01 | 1997-10-01 | $7700.00 | Window Closed / Lapsed |