Patent US3558371A successfully refreshed from Google Patents.
US3558371A
Expired / Lapsed
US
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Method of making permanent magnet material powders
Assignee: General Electric Co
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Filing: 1968-05-20
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Granted: 1971-01-26
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Expires: 1988-05-20
Abstract
Abstract THE GRINDING OF BULK PERMANENT MAGNET MATERIAL TO POWDER CAN RESULT IN A RELATIVELY LOW VALUE OF THE MAXIMUM COERCIVE FORCE OBTAINABLE. BY THE PRESENT METHOD INVOLVING IMMERSION OF SUCH BULK MATERIAL FOR A SHORT TIME IN NITRIFIC ACID, HYDROCHLORIC ACID, SULFURIC ACID, PHOSPHORIC ACID, OR ACETIC ACID, POWDER PARTICLES ARE PRODUCED WHICH HAVE HIGH COERCIVE FORCES.
Inventors
- 👤 Joseph J Becker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:23
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04; H01F1/06; B; B22; B22F; B22F9/00; C; C22; C22C; C22C19/00; C22C19/07; H01F1/047; H01F1/053; H01F1/055; H01F1/0551; H01F1/0552
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |