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Patent US2727680A successfully refreshed from Google Patents.
US2727680A
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US
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Centrifugal fan
Assignee: Buffalo Forge Co
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Filing: 1951-08-02
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Granted: 1955-12-20
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Expires: 1971-08-02
Abstract
No abstract record available.
Inventors
- 👤 Richard D Madison
- 👤 Howard C Burgin
- 👤 Walter R Elliot
- 👤 Robert D Robson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:40
CPC Classifications
F; F04; F04D; F04D17/00; F04D17/08; F04D17/16; F04D17/162; F04D29/00; F04D29/40; F04D29/42; F04D29/4206; F04D29/4213
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US909863A
Cited
US2083996A
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US2050700A
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US2160666A
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US2117416A
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US2190245A
Cited
US2316608A
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US2453524A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1958-12-19 | 1959-06-20 | 1959-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-12-19 | 1963-06-20 | 1963-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-12-19 | 1967-06-20 | 1967-12-20 | $7700.00 | Window Closed / Lapsed |