US4295632A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for reducing torque on an air damper
Assignee: Schneider Electric Buildings Americas Inc
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Filing: 1978-09-28
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Granted: 1981-10-20
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Expires: 1998-09-28
Abstract
Abstract A volume air flow controller having a butterfly damper mounted within an air duct and movable between open and closed positions employs a baffle, located upstream from the damper, as an air flow impedance to change the flow conditions upstream from the damper so as to reduce the normal damper closing torque resulting from aerodynamic forces produced by air flow past the damper.
Inventors
- 👤 Roger P. Engelke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:33
CPC Classifications
F; F16; F16K; F16K1/00; F16K1/16; F16K1/18; F16K1/22; F16K47/00; F16K47/08; F24; F24F; F24F11/00; F24F11/70; F24F11/72; F24F11/74
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
181 words
A volume air flow controller comprising a duct, a butterfly damper mounted in the duct, said damper movable about a pivot and having leading and trailing portions, and control means adapted to position said damper to control air flow through the duct, and a fixed air flow impedance located in said duct upstream from said damper and extending across said duct generally in the direction of the damper axis, said air flow impedance medially positioned within said duct offset to the leading portion-side of the axis of said damper and displaced from substantially opposite duct wall portions so as to permit portions of the air flow to pass between said opposite duct wall portions and respective sides of said air flow impedance in the directions of said leading and trailing portions respectively, said impedance changing the air velocity profile within the duct so that the velocity of air acting upon at least a portion of the leading portion of said damper is reduced whereby the damper-closing torque resulting from the aerodynamic forces produced by air flow past said damper is reduced.
Claim 2
Dependent Claim
181 words
A volume air flow controller comprising a duct, a butterfly damper mounted in the duct, said damper movable about a pivot and having leading and trailing portions, and control means adapted to position said damper to control air flow through the duct, and a fixed air flow impedance located in said duct upstream from said damper and extending across said duct generally in the direction of the damper axis, said air flow impedance medially positioned within said duct offset to the leading portion-side of the axis of said damper and displaced from substantially opposite duct wall portions so as to permit portions of the air flow to pass between said opposite duct wall portions and respective sides of said air flow impedance in the directions of said leading and trailing portions respectively, said impedance changing the air velocity profile within the duct so that the velocity of air acting upon at least a portion of the leading portion of said damper is reduced whereby the damper-closing torque resulting from the aerodynamic forces produced by air flow past said damper is reduced.
Claim 3
Dependent Claim
17 words
A volume air flow controller according to claim 1 wherein said air flow impedance comprises a baffle.
Claim 4
Dependent Claim
31 words
A volume air flow controller according to claim 2 wherein said baffle comprises a substantially flat plate extending across said duct substantially parallel to the axis about which said damper pivots.
Claim 5
Dependent Claim
30 words
A volume air flow controller according to claim 2 wherein said baffle comprises a substantially flat plate located in a plane substantially perpendicular to the air flow in said duct.
Claim 6
Dependent Claim
30 words
A volume air flow controller according to claim 2 wherein said baffle comprises a substantially flat plate located in a plane parallel to the axis about which said damper pivots.
Claim 7
Dependent Claim
18 words
A volume air flow controller according to claim 2 wherein said baffle has at least one opening therethrough.
Claim 8
Dependent Claim
14 words
A volume air flow controller according to claim 6 wherein said baffle is honeycombed.
Claim 9
Dependent Claim
21 words
A volume air flow controller according to claim 1 wherein said air flow impedance comprises a plurality of baffles spaced apart.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-10-19 | 1985-04-20 | 1985-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-19 | 1989-04-20 | 1989-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-19 | 1993-04-20 | 1993-10-20 | $7700.00 | Window Closed / Lapsed |