US3768546A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Axial flow fan assembly
Assignee: Hudson Products Corp
•
Filing: 1971-12-27
•
Granted: 1973-10-30
•
Expires: 1991-12-27
Abstract
Abstract An axial flow fan assembly having two or more fans in series to provide successive fan stages in which less than the total number of fans are of the variable pitch type.
Inventors
- 👤 K Shipes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:31
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/26; F04D29/32; F04D29/34; F04D29/36; F04D29/362; F04D19/00; F04D19/007; F04D19/02; F04D19/024; F04D27/00; F04D27/002; F28; F28B; F28B1/00; F28B1/06; F28F; F28F2250/00; F28F2250/08; Y; Y10; Y10S; Y10S165/00; Y10S165/90
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
134 words
An air cooler, comprising a tube bundle, and an axial flow fan assembly mounted on one side of the tube bundle for causing air to pass thereacross, said fan assembly including a fan ring, first and second axial flow fans mounted coaxially within the fan ring and relatively close together, means for rotating the first and second fans, the blades of the first fan having a positive pitch which is non-adjustable during rotation thereof and arranged to move the air through the fan ring in a direction from said first fan to said second fan, and remotely operable means for adjusting the pitch of the blades of the second fan, during rotation thereof, within a range between positive pitches gerater than and less than the positive pitch of the blades of the first fan.
Claim 2
Dependent Claim
134 words
An air cooler, comprising a tube bundle, and an axial flow fan assembly mounted on one side of the tube bundle for causing air to pass thereacross, said fan assembly including a fan ring, first and second axial flow fans mounted coaxially within the fan ring and relatively close together, means for rotating the first and second fans, the blades of the first fan having a positive pitch which is non-adjustable during rotation thereof and arranged to move the air through the fan ring in a direction from said first fan to said second fan, and remotely operable means for adjusting the pitch of the blades of the second fan, during rotation thereof, within a range between positive pitches gerater than and less than the positive pitch of the blades of the first fan.
Claim 3
Dependent Claim
31 words
An air cooler of the character defined in claim 1, wherein said remotely operable pitch adjusting means includes means for adjusting the blades of the second fan to a negative pitch.
Claim 4
Dependent Claim
157 words
An air cooler, comprising a tube bundle, and an axial flow fan assembly mounted on one side of the tube bundle for causing air to pass thereacross, said fan assembly including a fan ring, first, second and third axial flow fans mounted coaxially within the fan ring, the first fan being relatively close to the second fan, and the second fan being relatively close to the third fan, means for rotating the first, second and third fans, the blades of the first fan having a positive pitch which is non-adjustable during rotation thereof and arranged to move the air through the fan ring in a direction from said first fan to said second fan, and remotely operable means for adjusting the pitch of the blades of each of the second and third fans, during rotation thereof, within a range between positive pitches greater than and less than the positive pitch of the blades of the first fan.
Claim 5
Dependent Claim
157 words
An air cooler, comprising a tube bundle, and an axial flow fan assembly mounted on one side of the tube bundle for causing air to pass thereacross, said fan assembly including a fan ring, first, second and third axial flow fans mounted coaxially within the fan ring, the first fan being relatively close to the second fan, and the second fan being relatively close to the third fan, means for rotating the first, second and third fans, the blades of the first fan having a positive pitch which is non-adjustable during rotation thereof and arranged to move the air through the fan ring in a direction from said first fan to said second fan, and remotely operable means for adjusting the pitch of the blades of each of the second and third fans, during rotation thereof, within a range between positive pitches greater than and less than the positive pitch of the blades of the first fan.
Claim 6
Dependent Claim
33 words
An air cooler of the character defined in claim 3, wherein said remotely operable pitch adjusting means includes means for adjusting the blades of the second and third fan to a negative pitch.
Claim 7
Dependent Claim
184 words
An air cooler, comprising a tube bundle, and an axial flow fan assembly mounted on one side of the tube bundle for causing air to pass thereacross, said fan assembly including a fan ring, first, second and third axial flow fans mounted coaxially within the fan ring, the third fan being relatively close to the second fan, and the second fan being relatively close to the third fan, means for rotating the first, second and third fans, the blades of each of the first and second fans having a postivie pitch which is non-adjustable during rotation thereof and arranged to move air through the fan ring in a direction from the first fan to the second fan and from the second fan to the third, with the pitch of the blades of the second fan being greater than the pitch of the blades of the third fan, and remotely operable means for adjusting the pitch of the blades of the third fan, during rotation thereof, within a range between the positive pitches greater than and less than the positive pitch of the second fan.
Claim 8
Dependent Claim
184 words
An air cooler, comprising a tube bundle, and an axial flow fan assembly mounted on one side of the tube bundle for causing air to pass thereacross, said fan assembly including a fan ring, first, second and third axial flow fans mounted coaxially within the fan ring, the third fan being relatively close to the second fan, and the second fan being relatively close to the third fan, means for rotating the first, second and third fans, the blades of each of the first and second fans having a postivie pitch which is non-adjustable during rotation thereof and arranged to move air through the fan ring in a direction from the first fan to the second fan and from the second fan to the third, with the pitch of the blades of the second fan being greater than the pitch of the blades of the third fan, and remotely operable means for adjusting the pitch of the blades of the third fan, during rotation thereof, within a range between the positive pitches greater than and less than the positive pitch of the second fan.
Claim 9
Dependent Claim
31 words
An air cooler of the character defined in claim 5, wherein said remotely operable pitch adjusting means includes means for adjusting the blade of the third fan to a negative pitch.
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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) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |