US3840624A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing a ferrite magnet
Assignee: ZF International UK Ltd
•
Filing: 1972-01-26
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Granted: 1974-10-08
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Expires: 1992-01-26
Abstract
Abstract 1. A METHOD OF MANUFACTURING A FERRITE MAGNET HAVING A REDUCED TENDENCY TO FORM AND PROPAGATE CRACKS IN THE GREEN COMPACT AND IN THE FINISHED MAGNET COMPRISING, (A) MIXING APOWDERED FERRITE MAGNET MATERIAL WITH A FIBROUS MATERIAL; (B) PRESSING THE MIXTURE OF POWDERED FERRITE MAGNET MATERIAL AND FIBROUS MATERIAL IN A MAGNETIC FIELD TO THEREBY PRODUCE A COMPACT OF THE DESIRED SHAPE; (C) DEMAGNETISING SAID COMPACT; AND (D) SINTERING SAID COMPACT.
Inventors
- 👤 T Tombs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:54
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/10; H01F1/11; H01F1/113
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
70 words
A METHOD OF MANUFACTURING A FERRITE MAGNET HAVING A REDUCED TENDENCY TO FORM AND PROPAGATE CRACKS IN THE GREEN COMPACT AND IN THE FINISHED MAGNET COMPRISING, (A) MIXING APOWDERED FERRITE MAGNET MATERIAL WITH A FIBROUS MATERIAL; (B) PRESSING THE MIXTURE OF POWDERED FERRITE MAGNET MATERIAL AND FIBROUS MATERIAL IN A MAGNETIC FIELD TO THEREBY PRODUCE A COMPACT OF THE DESIRED SHAPE; (C) DEMAGNETISING SAID COMPACT; AND (D) SINTERING SAID COMPACT.
Claim 2
Independent Claim
70 words
A METHOD OF MANUFACTURING A FERRITE MAGNET HAVING A REDUCED TENDENCY TO FORM AND PROPAGATE CRACKS IN THE GREEN COMPACT AND IN THE FINISHED MAGNET COMPRISING, (A) MIXING APOWDERED FERRITE MAGNET MATERIAL WITH A FIBROUS MATERIAL; (B) PRESSING THE MIXTURE OF POWDERED FERRITE MAGNET MATERIAL AND FIBROUS MATERIAL IN A MAGNETIC FIELD TO THEREBY PRODUCE A COMPACT OF THE DESIRED SHAPE; (C) DEMAGNETISING SAID COMPACT; AND (D) SINTERING SAID COMPACT.
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) | 1977-10-07 | 1978-04-08 | 1978-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-07 | 1982-04-08 | 1982-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-07 | 1986-04-08 | 1986-10-08 | $7700.00 | Window Closed / Lapsed |