Patent US2561840A successfully refreshed from Google Patents.
US2561840A
Expired / Lapsed
US
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Centrifugal fan
Assignee: MACHF Gebr STORK & CO N V
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Filing: 1946-06-05
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Granted: 1951-07-24
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Expires: 1966-06-05
Abstract
No abstract record available.
Inventors
- 👤 Jan C Busquet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:29
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)
USRE20394E
Cited
US1892303A
Cited
GB302953A
Cited
US1906180A
Cited
US1997506A
Cited
US1978129A
Cited
US2201437A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-07-23 | 1955-01-22 | 1955-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-07-23 | 1959-01-22 | 1959-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-07-23 | 1963-01-22 | 1963-07-24 | $7700.00 | Window Closed / Lapsed |