Patent US5246343A successfully refreshed from Google Patents.
US5246343A
Expired / Lapsed
US
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Fan assemblies and method of making same
Assignee: RB KANALFLAKT Inc
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Filing: 1991-12-23
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Granted: 1993-09-21
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Expires: 2011-12-23
Abstract
Abstract A low cost assembly and method for assembly of a fan having a hub, a spider with arms and blades attached to the arms is provided. The spider is arc welded to the hub and the blades are projection welded to the arms. The blades have a root, a tip, and an ear. The width or chord of the blade decreases from the root to the ear and then increases from the ear to the tip. The blade has an air foil shape defined by the arcs of two circles. The radii of the circles and, thus the profile of the blade, change as a function of the cord length and the camber of the blade. The blades have a pitch angle which decreases from the root to the ear. The spider arms are formed to match the pitch and are rotated slightly with respect to the horizontal. The result is a highly efficient, low cost fan blade assembly construction.
Inventors
- 👤 Jim Windsor
- 👤 Chuck Straight
- 👤 Samir Khouzam
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:38
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/26; F04D29/32; F04D29/325; F04D29/34; Y; Y10; Y10S; Y10S416/00; Y10S416/02; Y10S416/03; Y10S416/05
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
123 words
A fan assembly comprising an annular hub which fits over a motor axle to rotate therewith, a spider fixed to said hub, said spider having a plurality of arms, and a plurality of fan blades fixed to said spider arms having a root section and an ear section; said blade being in the form of an arc defining a chord which decreases along said root section and increases along said ear section, said blade having a blade depitch angle which decreases from the root to the top of said ear section and camber which is kept constant as a percent of said chord; said spider arms having a pitch angle to provide a pitch angle of between 22° -50° to said fan blades.
Claim 2
Dependent Claim
123 words
A fan assembly comprising an annular hub which fits over a motor axle to rotate therewith, a spider fixed to said hub, said spider having a plurality of arms, and a plurality of fan blades fixed to said spider arms having a root section and an ear section; said blade being in the form of an arc defining a chord which decreases along said root section and increases along said ear section, said blade having a blade depitch angle which decreases from the root to the top of said ear section and camber which is kept constant as a percent of said chord; said spider arms having a pitch angle to provide a pitch angle of between 22° -50° to said fan blades.
Claim 3
Dependent Claim
19 words
The fan assembly of claim 1 wherein said camber is from about 6% to about 12.5% of said chord.
Claim 4
Dependent Claim
22 words
The fan assembly of claim 1 wherein the blade depitch angle decreases at a rate of about 1.5° /inch to 3+ /inch.
Claim 5
Dependent Claim
18 words
The fan assembly of claim 3 wherein said blades have a pitch angle of between 22° -50° .
Claim 6
Dependent Claim
34 words
The fan assembly of claim 1 wherein the chord length decreases by about 0.15" per inch from the root to the ear section and increases by about 0.177" per inch along the ear section.
Claim 7
Dependent Claim
28 words
The fan assembly of claim 1, wherein said spider arms have a rib on one face extending the length thereof and a plurality of projections on another face.
Claim 8
Dependent Claim
20 words
The fan assembly of claim 6, wherein said spider arms are formed to match the pitch of said fan blades.
Claim 9
Dependent Claim
18 words
The fan assembly of claim 1 wherein said spider arms are rotated approximately 5° toward their leading edge.
Claim 10
Dependent Claim
136 words
A fan assembly comprising an annular hub which fits over a motor axle to rotate therewith, a spider fixed to said hub, said spider having a plurality of arms, and a plurality of fan blades fixed to said spider arms having a root section and an ear section; said blade being in the form of an arc defining a chord which decreases along said root section and increases along said ear section, the arc being defined by arcs of two circles, one arc defining 1/3 of the chord length, the other arc defining 1/2 the chord length; said blade having a blade pitch angle of between 22° -50° and a depitch angle which decreases from the root to the top of said ear section and camber which is kept constant as a percent of said chord.
Claim 11
Dependent Claim
136 words
A fan assembly comprising an annular hub which fits over a motor axle to rotate therewith, a spider fixed to said hub, said spider having a plurality of arms, and a plurality of fan blades fixed to said spider arms having a root section and an ear section; said blade being in the form of an arc defining a chord which decreases along said root section and increases along said ear section, the arc being defined by arcs of two circles, one arc defining 1/3 of the chord length, the other arc defining 1/2 the chord length; said blade having a blade pitch angle of between 22° -50° and a depitch angle which decreases from the root to the top of said ear section and camber which is kept constant as a percent of said chord.
Claim 12
Dependent Claim
67 words
An airfoil shaped fan blade having a root, a tip, an ear between said root and said tip, and a leading edged and a trailing edge, the distance between said edges defining a chord, said chord decreasing from said root to said ear at a rate of about 0.15"/inch of blade length and then increasing from said ear to said tip by about 0.177"/inch of blade length.
Claim 13
Dependent Claim
67 words
An airfoil shaped fan blade having a root, a tip, an ear between said root and said tip, and a leading edged and a trailing edge, the distance between said edges defining a chord, said chord decreasing from said root to said ear at a rate of about 0.15"/inch of blade length and then increasing from said ear to said tip by about 0.177"/inch of blade length.
Claim 14
Dependent Claim
83 words
An airfoil shaped fan blade having a root, a tip, an ear between said root and said tip, and a leading edged and a trailing edge, the distance between said edges defining a chord, said chord decreasing from said root to aid ear and then increasing from said ear to said tip; said airfoil shape being defined by a first arc, which defines said leading edge, and a second arc which defines said trailing edge; said fan blade having a constant camber ratio.
Claim 15
Dependent Claim
83 words
An airfoil shaped fan blade having a root, a tip, an ear between said root and said tip, and a leading edged and a trailing edge, the distance between said edges defining a chord, said chord decreasing from said root to aid ear and then increasing from said ear to said tip; said airfoil shape being defined by a first arc, which defines said leading edge, and a second arc which defines said trailing edge; said fan blade having a constant camber ratio.
Claim 16
Dependent Claim
15 words
The fan blade of claim 11 wherein said camber is about 6%-12.5% of the chord.
Claim 17
Dependent Claim
32 words
The fan blade of claim 12, wherein said arcs have radii, said radii changing along the length of aid blade, said radii being a function of said camber and said chord length.
Claim 18
Dependent Claim
71 words
An airfoil shaped fan blade having a root, a tip, an ear between said root and said tip, and a leading edge and a trailing edge, the distance between said edges defining a chord, said chord decreasing from said root to said ear and then increasing from said ear to said tip; said blade having a pitch which decreases along the length thereof at a rate of about 1.5°/inch to 3°/inch.
Claim 19
Dependent Claim
71 words
An airfoil shaped fan blade having a root, a tip, an ear between said root and said tip, and a leading edge and a trailing edge, the distance between said edges defining a chord, said chord decreasing from said root to said ear and then increasing from said ear to said tip; said blade having a pitch which decreases along the length thereof at a rate of about 1.5°/inch to 3°/inch.
Claim 20
Dependent Claim
74 words
An airfoil shaped fan blade having a root, a tip, an ear between said root and said tip, and a leading edged and a trailing edge, the distance between said edges defining a chord, said chord decreasing from said root to said ear and then increasing from said ear to said tip; said blade having a pitch which decreases along the length thereof; said blades have a pitch angle of between 25° -40° ;
Claim 21
Dependent Claim
74 words
An airfoil shaped fan blade having a root, a tip, an ear between said root and said tip, and a leading edged and a trailing edge, the distance between said edges defining a chord, said chord decreasing from said root to said ear and then increasing from said ear to said tip; said blade having a pitch which decreases along the length thereof; said blades have a pitch angle of between 25° -40° ;
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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) | 1996-09-20 | 1997-03-22 | 1997-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-09-20 | 2001-03-22 | 2001-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-09-20 | 2005-03-22 | 2005-09-21 | $7700.00 | Window Closed / Lapsed |