Patent US3856434A successfully refreshed from Google Patents.
US3856434A
Expired / Lapsed
US
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Centrifugal fan wheel
Assignee: AMERICAN DAVIDSON Inc
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Filing: 1973-10-18
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Granted: 1974-12-24
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Expires: 1993-10-18
Abstract
Abstract A centrifugal fan wheel and blade assembly is provided, including a center-plate, a side-plate, and a plurality of twopiece airfoil-type blades located between the plates, each blade having a tail-piece permanently secured between the plates, and a nose-piece removably secured between the plates for field replacement.
Inventors
- 👤 J Hoffmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:26
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/26; F04D29/28; F04D29/281; F04D29/282; F01; F01D; F01D5/00; F01D5/12; F01D5/14; F01D5/147; F04D29/30
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
142 words
A centrifugal fan wheel and blade assembly comprising, a center-plate, a side-plate axially spaced from said center-plate, a plurality of airfoil-type blades to be located between said center-plate and said side-plate, each of said airfoil blades having at least two segments including a nose-piece segment defining the leading edge of said airfoil in the assembled relation, said nose-piece segment being provided with an aperture extending longitudinally through the major axis of said nosepiece from the side-plate to the center-plate and a tail-piece segment defining the trailing edge of said airfoil in the assembled relation, means to permanently secure said tail-piece segment between said center-plate and said side-plate, and means to removably secure said nose-piece segment between said centerplate and said side-plate in the assembled relationship, wherein said removable securing means includes a bolt extending through said aperture and said center- and side-plates.
Claim 2
Dependent Claim
142 words
A centrifugal fan wheel and blade assembly comprising, a center-plate, a side-plate axially spaced from said center-plate, a plurality of airfoil-type blades to be located between said center-plate and said side-plate, each of said airfoil blades having at least two segments including a nose-piece segment defining the leading edge of said airfoil in the assembled relation, said nose-piece segment being provided with an aperture extending longitudinally through the major axis of said nosepiece from the side-plate to the center-plate and a tail-piece segment defining the trailing edge of said airfoil in the assembled relation, means to permanently secure said tail-piece segment between said center-plate and said side-plate, and means to removably secure said nose-piece segment between said centerplate and said side-plate in the assembled relationship, wherein said removable securing means includes a bolt extending through said aperture and said center- and side-plates.
Claim 3
Dependent Claim
20 words
Apparatus of claim 1 wherein said nose-piece segment is removably secured to the skin of said tail-piece with threaded fasteners.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-23 | 1978-06-24 | 1978-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-23 | 1982-06-24 | 1982-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-23 | 1986-06-24 | 1986-12-24 | $7700.00 | Window Closed / Lapsed |