US3899156A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single blade fire damper
Assignee: Individual
•
Filing: 1974-01-23
•
Granted: 1975-08-12
•
Expires: 1994-01-23
Abstract
Abstract A fire damper for use in small openings comprises a single blade articulated about a hinge within a frame, which blade is movable between an open and closed position. In the open position a fusible link and strap retain the blade. When the link is released a negator extension-type spring mounted on the frame forces the blade to close the opening through the frame. A blade lock mounted on the blade engages the frame to retain the blade in the closed position.
Inventors
- 👤 Francis J Mccabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 01:27
CPC Classifications
F; F16; F16K; F16K17/00; F16K17/36; F16K17/38; F16K17/386; A; A62; A62C; A62C2/00; A62C2/06; A62C2/24; A62C2/241; A62C2/242; Y; Y10; Y10T; Y10T137/00; Y10T137/1624; Y10T137/1797; Y10T137/1819; Y10T137/7722; Y10T137/7723; Y10T137/7724; Y10T292/00; Y10T292/08; Y10T292/0911; Y10T292/0926
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
199 words
A fire damper, comprising: a. a frame, said frame defining a flow passage therethrough and having a flange thereon inwardly depending from the walls thereof; b. a blade mounted within said frame to articulate about one edge of said blade so as to be movable between open and closed positions with respect to said frame; c. spring means mounted to said frame and engaging the free swinging portion of said blade to exert a force thereon to move said blade from said open to said closed position; d. lock means for securely engaging the frame and the blade in the closed position to retain the blade in that position, said lock means comprising a pivotally mounted latch member and a spring, said latch member having a free end with a beveled surface thereon and having a slot defined therein, said beveled surface positioned to engage the inwardly depending flange of the frame on movement of said blade from an open position to a closed position, continued movement thereof to cam said latch about its pivot to allow said slot to matably engage said flange in the closed position, thereby producing positive retention of the blade in the closed position.
Claim 2
Dependent Claim
199 words
A fire damper, comprising: a. a frame, said frame defining a flow passage therethrough and having a flange thereon inwardly depending from the walls thereof; b. a blade mounted within said frame to articulate about one edge of said blade so as to be movable between open and closed positions with respect to said frame; c. spring means mounted to said frame and engaging the free swinging portion of said blade to exert a force thereon to move said blade from said open to said closed position; d. lock means for securely engaging the frame and the blade in the closed position to retain the blade in that position, said lock means comprising a pivotally mounted latch member and a spring, said latch member having a free end with a beveled surface thereon and having a slot defined therein, said beveled surface positioned to engage the inwardly depending flange of the frame on movement of said blade from an open position to a closed position, continued movement thereof to cam said latch about its pivot to allow said slot to matably engage said flange in the closed position, thereby producing positive retention of the blade in the closed position.
Claim 3
Dependent Claim
21 words
The invention of claim 1 wherein said spring engages said latch to urge it in a direction to engage said flange.
Claim 4
Dependent Claim
24 words
The invention of claim 1 wherein said latch has a curved portion permitting pivotal movement in one direction to allow engagement with said flange.
Claim 5
Dependent Claim
34 words
The invention of claim 3 wherein said latch has an end portion preventing pivotal movement in the opposite direction beyond a predetermined point, so that said beveled surface will engage said flange as aforesaid.
Claim 6
Dependent Claim
36 words
The invention of claim 1 wherein said blade is shaped and arranged to lie behind said flange and not obstruct the air flow through said device when said device is positioned in an air flow system.
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) | 1978-08-11 | 1979-02-10 | 1979-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-11 | 1983-02-10 | 1983-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-11 | 1987-02-10 | 1987-08-12 | $7700.00 | Window Closed / Lapsed |