US2113391A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Centrifugal fan
Assignee: BF Sturtevant Co
•
Filing: 1937-04-16
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Granted: 1938-04-05
•
Expires: 1957-04-16
Abstract
No abstract record available.
Inventors
- 👤 Amos C Bartlett
- 👤 Merton S Leonard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:51
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/40; F04D29/42; F04D29/44; F04D29/46; F04D29/462; F04D29/4206; F04D29/4213; F05; F05D; F05D2250/00; F05D2250/50; F05D2250/51
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1941-04-04 | 1941-10-04 | 1942-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1945-04-04 | 1945-10-04 | 1946-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1949-04-04 | 1949-10-04 | 1950-04-05 | $7700.00 | Window Closed / Lapsed |