Patent US2818387A successfully refreshed from Google Patents.
US2818387A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Square loop ferromagnetic material
Assignee: US Philips Corp
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Filing: 1954-10-28
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Granted: 1957-12-31
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Expires: 1974-10-28
Abstract
No abstract record available.
Inventors
- 👤 Paul W Beck
- 👤 Kenneth E Matteson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:35
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/26; C04B35/265
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
51 words
A FERROMAGNETIC MATERIAL HAVING A SUBSTANTIALLY RECTANGULAR HYSTERESIS LOOP CONSISTING ESSENTIALLY OF THE REACTION PRODUCT OBTAINED BY FIRING IN AN ATMOSPHERE CONTANINING NOT MORE OXYGEN THAN AIR AND AT A TEMPERATURE OF ABOUT 1100*C. TO 1400*C. OF A FINELY-DIVIDED MIXTURE OF BETWEEN ABOUT 40 AND 53 MOL PERCENT OF FE2O3, BETWEEN
Claim 2
Dependent Claim
51 words
A FERROMAGNETIC MATERIAL HAVING A SUBSTANTIALLY RECTANGULAR HYSTERESIS LOOP CONSISTING ESSENTIALLY OF THE REACTION PRODUCT OBTAINED BY FIRING IN AN ATMOSPHERE CONTANINING NOT MORE OXYGEN THAN AIR AND AT A TEMPERATURE OF ABOUT 1100*C. TO 1400*C. OF A FINELY-DIVIDED MIXTURE OF BETWEEN ABOUT 40 AND 53 MOL PERCENT OF FE2O3, BETWEEN
References Cited (Backward Citations)
US2723238A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-12-30 | 1961-07-01 | 1961-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-12-30 | 1965-07-01 | 1965-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-12-30 | 1969-07-01 | 1969-12-31 | $7700.00 | Window Closed / Lapsed |