US4063852A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Axial flow impeller with improved blade shape
Assignee: Madison Management Group Inc
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Filing: 1976-01-28
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Granted: 1977-12-20
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Expires: 1996-01-28
Abstract
Abstract An axial flow impeller for low pressure ratio applications in the range 1.03 and below and comprising a hub carrying a plurality of similar circumaxially arranged air moving blades. Each blade has a root portion attached to the hub and a radially outwardly disposed tip portion. The camber of each blade decreases from root to tip with 0.1203 root camber and .023 tip camber for a ratio of 5.23 to 1. Pitch also decreases from root to tip with a root pitch of 46° and a tip pitch of 27.4° for a ratio of 1.68 to 1. Chord increases from root to tip with a 1.528 inch root chord and a 2.59 inch tip chord for a 1.7 to 1 ratio. The blade camber and chord both change gradually at the blade inner and mid portions with a 35% camber decrease in the outermost 20% of blade span, and with substantially all of the chord increase occurring beyond the blade midpoint.
Inventors
- 👤 John F. O'Connor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:41
CPC Classifications
F; F01; F01D; F01D5/00; F01D5/12; F01D5/14; F01D5/141
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
133 words
An axial flow air impeller for low pressure ratio applications in the range 1.03 and below; said impeller comprising a hub adapted for rotation about an axis and carrying a plurality of similar circumaxially arranged air moving blades, each of said blades having a root portion attached to the hub and a radially outwardly disposed tip portion with smoothly curving side edges therebetween, the camber of each blade decreasing nonlinearly in value as the blade is viewed from its said root portion to its said tip portion, and the chord measurement of each blade being substantially less at its root portion than at its tip portion, substantially in excess of 50% of the blade camber decrease and substantially all of the blade chord change occuring over the outermost 40% of the blade span.
Claim 2
Dependent Claim
133 words
An axial flow air impeller for low pressure ratio applications in the range 1.03 and below; said impeller comprising a hub adapted for rotation about an axis and carrying a plurality of similar circumaxially arranged air moving blades, each of said blades having a root portion attached to the hub and a radially outwardly disposed tip portion with smoothly curving side edges therebetween, the camber of each blade decreasing nonlinearly in value as the blade is viewed from its said root portion to its said tip portion, and the chord measurement of each blade being substantially less at its root portion than at its tip portion, substantially in excess of 50% of the blade camber decrease and substantially all of the blade chord change occuring over the outermost 40% of the blade span.
Claim 3
Dependent Claim
36 words
An axial flow air impeller as set forth in claim 1 wherein the camber at the root portion of each blade does not exceed 0.15 and the camber at the tip portion is at least 0.02.
Claim 4
Dependent Claim
36 words
An axial flow air impeller as set forth in claim 1 wherein the camber at the root portion of each blade is at least 0.1 and the camber at the tip portion does not exceed 0.04.
Claim 5
Dependent Claim
34 words
An axial flow air impeller as set forth in claim 1 wherein the ratio of camber at the blade root portion to camber at the blade tip portion is less than 7.5 to 1.
Claim 6
Dependent Claim
34 words
An axial flow air impeller as set forth in claim 1 wherein the ratio of camber at the blade root portion to camber at the blade tip portion is more than 2.5 to 1.
Claim 7
Dependent Claim
34 words
An axial flow air impeller as set forth in claim 1 wherein the ratio of blade root to tip camber is no higher than 7.5 to 1 and no lower than 2.5 to 1.
Claim 8
Dependent Claim
31 words
An axial flow air impeller as set forth in claim 1 wherein camber at the blade root portion is approximately 0.12 and camber at the blade tip portion is approximately 0.02.
Claim 9
Dependent Claim
25 words
An axial flow air impeller as set forth in claim 1 wherein the ratio of blade root to tip camber is approximately 5.2 to 1.
Claim 10
Dependent Claim
44 words
An axial flow air impeller as set forth in claim 1 wherein the pitch decreases from root to tip, and wherein pitch at the root portion of each blade does not exceed 70° and the pitch at the tip portion is at least 10°.
Claim 11
Dependent Claim
36 words
An axial flow air impeller as set forth in claim 9 wherein the pitch at the root portion of each blade is at least 30° and the pitch at the tip portion does not exceed 20°.
Claim 12
Dependent Claim
34 words
An axial flow air impeller as set forth in claim 9 wherein the ratio of pitch at the blade root portion to pitch at the blade tip portion is less than 7 to 1.
Claim 13
Dependent Claim
34 words
An axial flow air impeller as set forth in claim 9 wherein the ratio of pitch at the blade root portion to pitch at the blade tip portion is more than 3 to 2.
Claim 14
Dependent Claim
34 words
An axial flow air impeller as set forth in claim 9 wherein the ratio of blade root to tip pitch is no higher than 7 to 1 and no lower than 3 to 2.
Claim 15
Dependent Claim
31 words
An axial flow air impeller as set forth in claim 9 wherein pitch at the blade root portion is approximately 46° and pitch at the blade tip portion is approximately 27°.
Claim 16
Dependent Claim
25 words
An axial flow air impeller as set forth in claim 9 wherein the ratio of blade root to tip pitch is approximately 1.7 to 1.
Claim 17
Dependent Claim
34 words
An axial flow air impeller as set forth in claim 1 wherein the ratio of chord at the blade tip portion to chord at the blade root portion is less than 2.5 to 1.
Claim 18
Dependent Claim
34 words
An axial flow air impeller as set forth in claim 1 wherein the ratio of chord at the blade tip portion to chord at the blade root portion is more than 1.3 to 1.
Claim 19
Dependent Claim
34 words
An axial flow air impeller as set forth in claim 1 wherein the ratio of blade tip to root chord is no higher than 2.5 to 1 and no lower than 1.3 to 1.
Claim 20
Dependent Claim
37 words
An axial flow air impeller as set forth in claim 1 wherein the chord measurement at the blade root portion is approximately 1.5 inches and the chord measurement at the blade tip portion is approximately 2.6 inches.
Claim 21
Dependent Claim
25 words
An axial flow air impeller as set forth in claim 1 wherein the ratio of blade tip to root chord is approximately 1.7 to 1.
Claim 22
Dependent Claim
44 words
An axial flow air impeller as set forth in claim 1 wherein blade camber decreases from approximately 0.12 to approximately 0.02 over the root to tip blade span, and wherein blade chord increases by 60% to 80% over the root to tip blade span.
Claim 23
Dependent Claim
28 words
An axial flow air impeller as set forth in claim 1 wherein blade camber decreases approximately 35% over the outermost 20% of the root to tip blade span.
Claim 24
Dependent Claim
39 words
An axial flow air impeller as set forth in claim 1 wherein the blade side edges are substantially straight in the innermost 60% of the blade span and flare arcuately outwardly in the outermost 40% of the blade span.
References Cited (Backward Citations)
CA516440A
Cited
US995562A
Cited
US1088883A
Cited
US1546554A
Cited
US1515268A
Cited
GB228177A
Cited
AT115470B
Cited
US1688809A
Cited
US1891612A
Cited
US1855660A
Cited
US3023709A
Cited
DE1805961A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-12-19 | 1981-06-20 | 1981-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-19 | 1985-06-20 | 1985-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-19 | 1989-06-20 | 1989-12-20 | $7700.00 | Window Closed / Lapsed |