US3429660A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alumina production
Assignee: Engelhard Industries Inc
•
Filing: 1964-12-08
•
Granted: 1969-02-25
•
Expires: 1984-12-08
Abstract
No abstract record available.
Inventors
- 👤 Carl D Keith
- 👤 Kurt W Cornely
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:51
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/42; C01F7/428; C01P; C01P2002/00; C01P2002/02; C01P2002/60; C01P2004/00; C01P2004/51; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/12
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2258099A
Cited
US2336597A
Cited
US2758011A
Cited
US2950169A
Cited
US2915475A
Cited
US3222130A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-02-25 | 1972-08-26 | 1973-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-02-25 | 1976-08-26 | 1977-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-02-25 | 1980-08-26 | 1981-02-25 | $7700.00 | Window Closed / Lapsed |