US3594098A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fan with weighted flexible blades
Assignee: Fram Corp
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Filing: 1969-09-15
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Granted: 1971-07-20
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Expires: 1989-09-15
Abstract
Abstract An automotive fan having flexible curved blades of resilient material which decamber as rotational speed increases in which an integral portion of each blade, having a mass of the order of 2 percent to 40 percent, preferably 8 percent to 10 percent, of the remainder of the blade, extends continuously along substantially the entire trailing edge of the blade and is folded upon itself at the trailing edge on the upstream side of the blade, thereby rigidifying and weighting the trailing edge to reduce vibration and noise and to assist the decambering of said blade at a predetermined rate.
Inventors
- 👤 Shrinivas V Pratinidhi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:43
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/26; F04D29/32; F04D29/38; F04D29/382
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
101 words
In an automotive fan having curved smooth-surfaced resilient blades which decamber as rotational speed increases, said blades each having a leading edge extending in a radial direction and an extended trailing edge generally parallel to said leading edge, that improvement in which continuous structure is positioned on and continuously connected to each of said blades along substantially the length of said trailing edge which is generally parallel to said leading edge, which structure provides a weight for reducing vibration and noise created by such vibration, and for assisting the decambering of said blades at a controlled rate at increased rotational speed.
Claim 2
Dependent Claim
101 words
In an automotive fan having curved smooth-surfaced resilient blades which decamber as rotational speed increases, said blades each having a leading edge extending in a radial direction and an extended trailing edge generally parallel to said leading edge, that improvement in which continuous structure is positioned on and continuously connected to each of said blades along substantially the length of said trailing edge which is generally parallel to said leading edge, which structure provides a weight for reducing vibration and noise created by such vibration, and for assisting the decambering of said blades at a controlled rate at increased rotational speed.
Claim 3
Dependent Claim
36 words
The fan as claimed in claim 1 in which the mass of each said weight is of the order of 8 percent to 10 percent of the mass of the blade on which it is positioned.
Claim 4
Dependent Claim
37 words
The fan as claimed in claim 1 wherein each weight-providing structure is formed integrally with the blade by a fold of a small radius at the trailing edge of the blade and is arcuate in cross section.
References Cited (Backward Citations)
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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) | 1974-07-19 | 1975-01-18 | 1975-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-19 | 1979-01-18 | 1979-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-19 | 1983-01-18 | 1983-07-20 | $7700.00 | Window Closed / Lapsed |