Patent US3438879A successfully refreshed from Google Patents.
US3438879A
Expired / Lapsed
US
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Protection of permselective diaphragm during electrolysis
Assignee: Hooker Chemical Corp
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Filing: 1967-07-31
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Granted: 1969-04-15
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Expires: 1987-07-31
Abstract
No abstract record available.
Inventors
- 👤 Morton S Kircher
- 👤 George T Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:07
CPC Classifications
C; C25; C25B; C25B1/00; C25B1/01; C25B1/34; C25B1/46
Claims Analysis
Total Claims: 0
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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) | 1972-04-14 | 1972-10-14 | 1973-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-04-14 | 1976-10-14 | 1977-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-04-14 | 1980-10-14 | 1981-04-15 | $7700.00 | Window Closed / Lapsed |