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US1684645A
Expired / Lapsed
US
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Ion concentration control
Assignee: Leeds and Northrup Co
•
Filing: 1922-01-03
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Granted: 1928-09-18
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Expires: 1942-01-03
Abstract
No abstract record available.
Inventors
- 👤 Irving B Smith
- 👤 Earl A Keeler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:35
CPC Classifications
G; G05; G05D; G05D21/00; G05D21/02; Y; Y10; Y10T; Y10T137/00; Y10T137/0318; Y10T137/0324; Y10T137/0329; Y10T137/034
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) | 1931-09-18 | 1932-03-19 | 1932-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1935-09-18 | 1936-03-19 | 1936-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1939-09-18 | 1940-03-19 | 1940-09-18 | $7700.00 | Window Closed / Lapsed |