US2433544A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sectional duct means having a fan for removing air from an enclosure
Assignee: Individual
•
Filing: 1945-01-24
•
Granted: 1947-12-30
•
Expires: 1965-01-24
Abstract
No abstract record available.
Inventors
- 👤 Robert E Blake
- 👤 Walter L Thomas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:41
CPC Classifications
F; F24; F24F; F24F7/00; F24F7/04; F24F7/06; F24F7/065
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US780247A
Cited
US735823A
Cited
US832247A
Cited
US932761A
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US968854A
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US1027740A
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US1138470A
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GB191308621A
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US1230282A
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CH78506A
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US1416381A
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US1518162A
Cited
US2034995A
Cited
US2087637A
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US2053336A
Cited
US2216046A
Cited
US2311948A
Cited
US2350735A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-12-29 | 1951-06-30 | 1951-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-12-29 | 1955-06-30 | 1955-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-12-29 | 1959-06-30 | 1959-12-30 | $7700.00 | Window Closed / Lapsed |