US2925389A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ferromagnetic cores and method
Assignee: US Philips Corp
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Filing: 1954-12-20
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Granted: 1960-02-16
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Expires: 1974-12-20
Abstract
No abstract record available.
Inventors
- 👤 Esveldt Cornelis Jacobus
- 👤 Gorter Evert Willem
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:11
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/26; C04B35/2608; C04B35/2625
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
88 words
A FERROMAGNETIC FERRITE HAVING A SUBSTANTIALLY SQUARE HYSTERESIS LOOP FORMED BY FIRING AT A TEMPERATURE OF ABOUT 1375* TO 1475*C. IN AN ATMOSPHERE CONTAINING MORE THAN 50% BY VOLUME OF OXYGEN A FINELY-DIVIDED MIXTURE OF NICKEL, MAGNESIUM AND IRON OXIDES IN PROPORTIONS CORRESPONDING TO THE FORMULA: NIXMG(1-X)FE2O4, IN WHICH X IS BETWEEN ABOUT 0.2 AND 0.8, SAID FERRITE HAVING A COERCIVE FORCE (HC) LESS THAN 4 OERSTED AND FULFILLING AT LEAST ONE OF THE FOLLOWING CONDITIONS: (A) BR/BCL NOT LESS THAN 0.7, (B) (RS)MAX NOT LESS THAN 0.6.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-02-15 | 1963-08-17 | 1964-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-02-15 | 1967-08-17 | 1968-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-02-15 | 1971-08-17 | 1972-02-16 | $7700.00 | Window Closed / Lapsed |