US3864808A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of deforming sintered magnets without significantly reducing magnetic properties
Assignee: General Electric Co
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Filing: 1973-09-06
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Granted: 1975-02-11
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Expires: 1993-09-06
Abstract
Abstract A method of hot-forming aligned sintered magnets. Such magnets are heated to a temperature at which plastic deformation can take place but which is below their sintering temperature. Under such conditions deformation can take place without sufficient magnetic reorientation to bring about a serious reduction in magnetic properties. After heating in the manner described above the magnet is slowly bent in a die over a period of not less than one-half hour to achieve a bending angle of about 90* to produce the desired deformation.
Inventors
- 👤 Manfred Doser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:23
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/24; H; H01; H01F; H01F41/00; H01F41/02; H01F41/0253; H01F41/0273; H01F41/028; Y; Y10; Y10S; Y10S72/00; Y10S72/70; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49075; Y10T29/49076
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
62 words
The method of forming a sintered magnet produced from powdered metal into various shapes by plastic deformation without significantly reducing desired magnetic properties which comprises: heating said magnet to a temperature below the melting temperature but at a temperature at which plastic deformation can take place, and, while maintaining said temperature, die-forming said magnet at a rate slow enough to prevent recrystallization.
Claim 2
Independent Claim
62 words
The method of forming a sintered magnet produced from powdered metal into various shapes by plastic deformation without significantly reducing desired magnetic properties which comprises: heating said magnet to a temperature below the melting temperature but at a temperature at which plastic deformation can take place, and, while maintaining said temperature, die-forming said magnet at a rate slow enough to prevent recrystallization.
Claim 3
Dependent Claim
15 words
The method of claim 1 in which the sintered magnet is a cobalt-rare earth magnet.
Claim 4
Dependent Claim
18 words
The method of claim 2 in which the sintered magnet is in the form of an elongated bar.
Claim 5
Independent Claim
49 words
The method of bending a cobalt-rare earth flat magnet without significantly reducing desired magnetic properties which comprises: heating said magnet to a temperature below its melting temperature but at which plastic deformation takes place; and die-bending said magnet at a rate not exceeding about 9* per inch per minute.
Claim 6
Independent Claim
49 words
The method of bending a cobalt-rare earth flat magnet without significantly reducing desired magnetic properties which comprises: heating said magnet to a temperature below its melting temperature but at which plastic deformation takes place; and die-bending said magnet at a rate not exceeding about 9* per inch per minute.
Claim 7
Dependent Claim
16 words
The method of claim 4 wherein the bending rate is about 3* per inch per minute.
Claim 8
Dependent Claim
17 words
The method of claim 4 wherein the die-bending takes place at a temperature between 700*C to 1,150*C.
References Cited (Backward Citations)
US1768529A
Cited
US2241441A
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US2219423A
Cited
US3428498A
Cited
US3469433A
Cited
US3785038A
Cited
US3766642A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-10 | 1978-08-12 | 1979-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-10 | 1982-08-12 | 1983-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-10 | 1986-08-12 | 1987-02-11 | $7700.00 | Window Closed / Lapsed |