Patent US2423739A successfully refreshed from Google Patents.
US2423739A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ventilator for buildings
Assignee: Individual
•
Filing: 1945-02-19
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Granted: 1947-07-08
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Expires: 1965-02-19
Abstract
No abstract record available.
Inventors
- 👤 Tillman George
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:25
CPC Classifications
F; F24; F24F; F24F7/00; F24F7/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-07-07 | 1951-01-06 | 1951-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-07-07 | 1955-01-06 | 1955-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-07-07 | 1959-01-06 | 1959-07-08 | $7700.00 | Window Closed / Lapsed |