Patent US3252913A successfully refreshed from Google Patents.
US3252913A
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Method for preparing manganese-zincferrous ferrite
Assignee: US Philips Corp
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Filing: 1963-03-21
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Granted: 1966-05-24
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Expires: 1983-03-21
Abstract
No abstract record available.
Inventors
- 👤 Cornelis Leonardus Maria Gils
- 👤 Stijntje Theodorus G Wilhelmus
- 👤 Johannes Gerardina Wilhelmu Wa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:18
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/26; C04B35/2658
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
158 words
A METHOD OF MANUFACTURING A MANGANESE-ZINC-FERROUS FERRITE COMPRISING THE STEPS, FORMING A MIXTURE OF OXIDES OF MANGANESE, ZINC AND IRON IN PROPORTIONS FORMING A MANGANESE-ZINC-FERROUS FERRITE UPON HEATING, HEATING SAID MIXTURE IN AN ATMOSPHERE CONTAINING AT LEAST 99% BY VOLUME OF OXYGEN AT A TEMPERATURE OF ABOUT 1375*C. TO 1450*C. FOR A SUFFICIENT TIME TO FORM A MANGANESE-ZINCFERROUS FERRITE, THEN DECREASING THE TEMPERATURE TO BETWEEN 1250*C. AND 1350*C., REDUCING THE OXYGEN CONTENT OF THE ATMOSPHERE TO BETWEEN 0.1 AND 0.5% BY VOLUME, MAINTAINING THE FERRITE AT SAID LATTER TEMPERATURE FOR AT LEAST 30 MINUTES, THEREAFTER COOLING SAID FERRITE TO A TEMPERATURE OF 900*C., REDUCING THE OXYGEN CONTENT OF SAID ATMOSPHERE TO 0.01% BY VOLUME WHEN SAID TEMPERATURE REACHES 900*C., THE OXYGEN CONTENT BEING REDUCED COMMENCING NOT MORE THAN 15 MINUTES PRIOR TO THE START OF THE LATTER COOLING STEP AND NOT LATER THAN THE INSTANT SAID LATTER COOLING COMMENCES, AND COOLING SAID FERRITE FROM 900*C. TO AMBIENT TEMPERATURE.
Claim 2
Independent Claim
158 words
A METHOD OF MANUFACTURING A MANGANESE-ZINC-FERROUS FERRITE COMPRISING THE STEPS, FORMING A MIXTURE OF OXIDES OF MANGANESE, ZINC AND IRON IN PROPORTIONS FORMING A MANGANESE-ZINC-FERROUS FERRITE UPON HEATING, HEATING SAID MIXTURE IN AN ATMOSPHERE CONTAINING AT LEAST 99% BY VOLUME OF OXYGEN AT A TEMPERATURE OF ABOUT 1375*C. TO 1450*C. FOR A SUFFICIENT TIME TO FORM A MANGANESE-ZINCFERROUS FERRITE, THEN DECREASING THE TEMPERATURE TO BETWEEN 1250*C. AND 1350*C., REDUCING THE OXYGEN CONTENT OF THE ATMOSPHERE TO BETWEEN 0.1 AND 0.5% BY VOLUME, MAINTAINING THE FERRITE AT SAID LATTER TEMPERATURE FOR AT LEAST 30 MINUTES, THEREAFTER COOLING SAID FERRITE TO A TEMPERATURE OF 900*C., REDUCING THE OXYGEN CONTENT OF SAID ATMOSPHERE TO 0.01% BY VOLUME WHEN SAID TEMPERATURE REACHES 900*C., THE OXYGEN CONTENT BEING REDUCED COMMENCING NOT MORE THAN 15 MINUTES PRIOR TO THE START OF THE LATTER COOLING STEP AND NOT LATER THAN THE INSTANT SAID LATTER COOLING COMMENCES, AND COOLING SAID FERRITE FROM 900*C. TO AMBIENT TEMPERATURE.
References Cited (Backward Citations)
US3027327A
Cited
US3020236A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-05-23 | 1969-11-22 | 1970-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-05-23 | 1973-11-22 | 1974-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-05-23 | 1977-11-22 | 1978-05-24 | $7700.00 | Window Closed / Lapsed |