Patent US2570451A successfully refreshed from Google Patents.
US2570451A
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US
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Liquid level control system
Assignee: Penn Electric Switch Co
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Filing: 1948-08-17
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Granted: 1951-10-09
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Expires: 1968-08-17
Abstract
No abstract record available.
Inventors
- 👤 Frederick W Hottenroth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:22
CPC Classifications
G; G05; G05D; G05D9/00; G05D9/12; Y; Y10; Y10T; Y10T137/00; Y10T137/1842; Y10T137/1939; Y10T137/7287; Y10T137/7297
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1294074A
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US1837213A
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US1988877A
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US2018097A
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US2083780A
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US2324647A
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US2394885A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-10-08 | 1955-04-09 | 1955-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-10-08 | 1959-04-09 | 1959-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-10-08 | 1963-04-09 | 1963-10-09 | $7700.00 | Window Closed / Lapsed |