US3908529A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Backdraft damper
Assignee: Individual
•
Filing: 1974-06-05
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Granted: 1975-09-30
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Expires: 1994-06-05
Abstract
Abstract The present invention provides a backdraft damper which is constructed of essentially two integral elements. A damper frame and blades are so formed as to eliminate the necessity of separate hinging elements while providing for pivotal movement of the blades with respect to the damper frame. This pivotal hinging action is free from binding, provides positive sealing in the closed position, and limits the arc of pivotal displacement of the blades to an acute angle. The present invention also provides two novel bearings which may be utilized in combination with the damper to ensure smooth operation in extreme temperature and weather conditions, and to facilitate assembly of the damper frame and blades from non-critical materials.
Inventors
- 👤 Francis J Mccabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:51
CPC Classifications
F; F24; F24F; F24F13/00; F24F13/08; F24F13/10; F24F13/14; F24F13/1486; F24F13/1406; F24F13/15; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7837; Y10T137/7838; Y10T137/7839; Y10T137/7898; Y10T137/7903
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
98 words
In a backdraft damper having a frame, at least one blade, and pivot means for allowing arcuate displacement of said blade with respect tO said frame, the improvement wherein said pivot means comprises at least two hook-shaped hinge elements formed in said frame, said hinge elements defining a surface having a hookshaped cross-section and at least one hook-shaped hinge portion formed in said blade, said hinge portion complementally configured to said hook-shaped hinge elements and slidably engaging said hinge elements, and wherein said pivot means further comprises bearing means disposed between said hinge elements and said hinge portion.
Claim 2
Dependent Claim
98 words
In a backdraft damper having a frame, at least one blade, and pivot means for allowing arcuate displacement of said blade with respect tO said frame, the improvement wherein said pivot means comprises at least two hook-shaped hinge elements formed in said frame, said hinge elements defining a surface having a hookshaped cross-section and at least one hook-shaped hinge portion formed in said blade, said hinge portion complementally configured to said hook-shaped hinge elements and slidably engaging said hinge elements, and wherein said pivot means further comprises bearing means disposed between said hinge elements and said hinge portion.
Claim 3
Dependent Claim
22 words
The invention of claim 1, wherein said bearing means comprises at least two bearings which engage the hinge portion of the blade.
Claim 4
Dependent Claim
18 words
The invention of claim 2, wherein said bearings conform to the interior surfaces of said hook-shaped hinge portion.
Claim 5
Dependent Claim
24 words
The invention of claim 3, wherein said bearings further comprise a U-shaped portion which engages one edge and two surfaces of said hinge portion.
Claim 6
Dependent Claim
32 words
The invention of claim 3, wherein each of said bearings further comprise a tab, said tab mating with a slot in said hinge portion, thereby fixing said bearing to said hinge portion.
Claim 7
Dependent Claim
219 words
A backdraft damper comprising a frame, at least one blade, and pivot means for allowing arcuate displacement of said blade between a closed and an open position with respect to said frame, wherein said frame is box shaped and is comprised of a plurality of flanges, at least one of which is an inwardly depending interior flange disposed within a plane which is parallel to and contiguous with a first side of the plane of said blade in said closed position, said interior flange being notched to form at least two hook shaped hinge elements which project generally away from the plane of said blade on said first side and are disposed on opposite sides of said frame, said hinge elements defining a surface having a hook shaped cross section; and wherein said pivot means comprises a hook shaped hinge portion formed in said blade and offset from the plane of said blade, and said hinge elements; said hinge portion being complementally configured to said hook shaped hinge elements and slidingly engaging said hinge elements, said hook shaped hinge elements and said hook shaped hinge portion being so articulated as to limit the arc of displacement of said blade with respect to said frame, whereby a seal is formed between said frame and said blade in the closed position.
Claim 8
Dependent Claim
219 words
A backdraft damper comprising a frame, at least one blade, and pivot means for allowing arcuate displacement of said blade between a closed and an open position with respect to said frame, wherein said frame is box shaped and is comprised of a plurality of flanges, at least one of which is an inwardly depending interior flange disposed within a plane which is parallel to and contiguous with a first side of the plane of said blade in said closed position, said interior flange being notched to form at least two hook shaped hinge elements which project generally away from the plane of said blade on said first side and are disposed on opposite sides of said frame, said hinge elements defining a surface having a hook shaped cross section; and wherein said pivot means comprises a hook shaped hinge portion formed in said blade and offset from the plane of said blade, and said hinge elements; said hinge portion being complementally configured to said hook shaped hinge elements and slidingly engaging said hinge elements, said hook shaped hinge elements and said hook shaped hinge portion being so articulated as to limit the arc of displacement of said blade with respect to said frame, whereby a seal is formed between said frame and said blade in the closed position.
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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) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |