US2792771A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heating and ventilating conduits with shutters
Assignee: Individual
•
Filing: 1952-05-24
•
Granted: 1957-05-21
•
Expires: 1972-05-24
Abstract
No abstract record available.
Inventors
- 👤 Robert V Burwen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 00:15
CPC Classifications
F; F24; F24F; F24F13/00; F24F13/08; F24F13/10; F24F13/12; Y; Y10; Y10T; Y10T74/00; Y10T74/18; Y10T74/18888; Y10T74/18912
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US800055A
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US1488090A
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US1718254A
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US1809223A
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US1942137A
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US1958342A
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US2087640A
Cited
GB525222A
Cited
US2515255A
Cited
US2519503A
Cited
US2627800A
Cited
US2662747A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-05-20 | 1960-11-19 | 1961-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-05-20 | 1964-11-19 | 1965-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-05-20 | 1968-11-19 | 1969-05-21 | $7700.00 | Window Closed / Lapsed |