Patent US2642337A successfully refreshed from Google Patents.
US2642337A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of converting crystalline alumina hydrate to alpha alumina
Assignee: Alcoa Corp
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Filing: 1948-06-09
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Granted: 1953-06-16
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Expires: 1968-06-09
Abstract
No abstract record available.
Inventors
- 👤 James W Newsome
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:08
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/44; C01F7/447; C01F7/448; C01F7/441; C01F7/442
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
34 words
THE METHOD OF CONVERTING CRYSTALLINE ALUMINA HYDRATE TO ALPHA ALUMINA, COMPRISING HEATING THE ALUMINA HYDRATE IN CONTACT WITH STEAM AT A PRESSURE OF 350-2500 POUNDS PER SQUARE INCH AND AT A TEMPERATURE OF 400-550*C.
Claim 2
Independent Claim
34 words
THE METHOD OF CONVERTING CRYSTALLINE ALUMINA HYDRATE TO ALPHA ALUMINA, COMPRISING HEATING THE ALUMINA HYDRATE IN CONTACT WITH STEAM AT A PRESSURE OF 350-2500 POUNDS PER SQUARE INCH AND AT A TEMPERATURE OF 400-550*C.
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) | 1956-06-15 | 1956-12-15 | 1957-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-15 | 1960-12-15 | 1961-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-15 | 1964-12-15 | 1965-06-16 | $7700.00 | Window Closed / Lapsed |