Patent US3712857A successfully refreshed from Google Patents.
US3712857A
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US
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Method for controlling a reduction cell
Assignee: Reynolds Metals Co
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Filing: 1968-05-20
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Granted: 1973-01-23
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Expires: 1988-05-20
Abstract
Abstract A METHOD OF OBJECTIVELY CONTROLLING AN ELECTROLYTIC CELL WHEREIN ALUMINA IS FED INTO THE CELL''S BATH IN RESPONSE TO THE DETECTION OF A PREDETERMINED CHANGE OF THE CELL''S RESISTANCE; BUT WHEREIN FEEDING IS PREVENTED FOR A GIVEN DWELL PERIOD AFTER EACH FEED CYCLE EVEN THOUGH SUBSE- QUENT FEEDING CONDITIONS OTHERWISE EXIST DURING THE DWELL PERIOD.
Inventors
- 👤 R Piller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:32
CPC Classifications
C; C25; C25C; C25C3/00; C25C3/06; C25C3/20
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-23 | 1976-07-24 | 1977-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-23 | 1980-07-24 | 1981-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-23 | 1984-07-24 | 1985-01-23 | $7700.00 | Window Closed / Lapsed |