US2638835A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Roof ventilator
Assignee: Individual
•
Filing: 1951-05-17
•
Granted: 1953-05-19
•
Expires: 1971-05-17
Abstract
No abstract record available.
Inventors
- 👤 Fern A Strawsine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:19
CPC Classifications
F; F24; F24F; F24F7/00; F24F7/02; F24F7/025
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) | 1956-05-18 | 1956-11-17 | 1957-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-05-18 | 1960-11-17 | 1961-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-05-18 | 1964-11-17 | 1965-05-19 | $7700.00 | Window Closed / Lapsed |