Patent US2521866A successfully refreshed from Google Patents.
US2521866A
Expired / Lapsed
US
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Air-heating furnace with automatically controlled air by-pass for preventing condensation
Assignee: Individual
•
Filing: 1946-09-09
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Granted: 1950-09-12
•
Expires: 1966-09-09
Abstract
No abstract record available.
Inventors
- 👤 Oran W Ott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:04
CPC Classifications
F; F24; F24H; F24H9/00; F24H9/20; F24H9/2064; F24H9/2085; F24H15/00; F24H15/20; F24H15/254; F24H15/30; F24H15/305; F24H15/31; F24H15/33; F24H15/355; F24H15/36; Y; Y10; Y10S; Y10S165/00; Y10S165/921
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US843909A
Cited
US1737189A
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US1734962A
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US1746564A
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US1748091A
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US1914604A
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US1945223A
Cited
US1958331A
Cited
US2015960A
Cited
US2190349A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-09-11 | 1954-03-13 | 1954-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-09-11 | 1958-03-13 | 1958-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-09-11 | 1962-03-13 | 1962-09-12 | $7700.00 | Window Closed / Lapsed |