US3830743A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ceramic permanent magnet
Assignee: Shell USA Inc
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Filing: 1971-09-27
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Granted: 1974-08-20
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Expires: 1991-09-27
Abstract
Abstract MAGNETOPLUMBITES HAVING THE FORMULA PHO.NFE203, WHEREIN N IS FROM ABOUT 3 TO ABOUT 6.5, HAVING DENSITES OF NOT LESS THAN 85% OF THE THEORETICAL MAXIMUM, HAVING AVERAGE CRYSTALLITE SIZES OF LESS THAN ABOUT 2.0 MICRONS, HAVING AT LEAST 90% OF THEIR CRYSTALLITES LESS THAN 2.5 MICRONS IN DIAMETER AND CRYSTALLITE ORIENTATIONS OF NOT LESS THAN ABOUT 70% YIELD PERMANENT CERAMIC MAGNETS HAVING BOTH HIGH COERCIVE FORCES AND REMANENCES.
Inventors
- 👤 C Schlaudt
- 👤 R Clendenen
- 👤 E Olson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 02:34
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/10; C; C04; C04B; C04B35/00; C04B35/01; C04B35/26; C04B35/2683
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) | 1977-08-19 | 1978-02-18 | 1978-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-19 | 1982-02-18 | 1982-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-19 | 1986-02-18 | 1986-08-20 | $7700.00 | Window Closed / Lapsed |