Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
119 words
A ventilating damper assembly including, in combination: a ventilating ceiling duct having upper and lower open ends; first normally-closed pressure-opened damper means for closing said duct, said damper means located to open in response to air flow from the lower to upper end of said duct and biased to normally close said duct to prevent backdrafts into said duct from the upper to lower end thereof; abutment flange means located in said duct and extending into the space defined by said duct; and normally-open temperature-responsive anti-draft damper means in said duct and closed against said abutment flange means in response to temperatures above a predetermined temperature to close said duct irrespective of the position of said first damper means.
Claim 2
Dependent Claim
119 words
A ventilating damper assembly including, in combination: a ventilating ceiling duct having upper and lower open ends; first normally-closed pressure-opened damper means for closing said duct, said damper means located to open in response to air flow from the lower to upper end of said duct and biased to normally close said duct to prevent backdrafts into said duct from the upper to lower end thereof; abutment flange means located in said duct and extending into the space defined by said duct; and normally-open temperature-responsive anti-draft damper means in said duct and closed against said abutment flange means in response to temperatures above a predetermined temperature to close said duct irrespective of the position of said first damper means.
Claim 3
Dependent Claim
67 words
The combination according to claim 1 wherein said first pressure-opened damper means comprises a damper lid pivotally mounted along one edge thereof to the upper end of said duct and having dimensions selected to cause said damper lid to overlie the upper end of said duct in the closed position, said damper lid being closed by gravity and opened in response to air pressure within said duct.
Claim 4
Dependent Claim
27 words
The combination according to claim 2 wherein said duct is of rectangular cross-section and said damper lid is pivotally mounted on the edge of one side thereof.
Claim 5
Dependent Claim
130 words
The combination according to claim 1 wherein said duct comprises four substantially parallel sidewalls forming an open-ended enclosure having a rectangular cross section and further wherein said abutment flange means comprises at least one abutment means on at least one of said sidewalls extending into the space defined by said sidewalls; wherein said anti-draft damper means is located on another sidewall and is spring biased to close against said abutment means; and a link of fusible material attached said anti-draft damper means to said another sidewall against such spring bias, said fusible line holding said anti-draft damper means in an open position but subject to releasing said damper means to close under the action of said spring bias against said abutment means in response to temperature above said predetermined temperature.
Claim 6
Dependent Claim
25 words
The combination according to claim 4 wherein said abutment comprises an inwardly extending flange on the sidewalls of said duct at the upper end thereof.
Claim 7
Dependent Claim
101 words
The combination according to claim 5 wherein said temperature-responsive anti-draft damper means comprises first and second damper means each pivotally attached in said duct on opposite sidewalls thereof and each having a length sufficient to extend over half the distance between such opposite sidewalls, so that upon closure thereof, said first and second anti-draft damper means overlay one another, each of said first and second anti-draft damper means being spring-biased to close against said flange and being held open against said spring bias by first and second fusible links connecting said first and second anti-draft damper means to said opposite sidewalls.
Claim 8
Dependent Claim
42 words
The combination according to claim 6 wherein said first and second fusible links are selected to release said first and second damper means at first and second different temperatures above said predetermined temperature to facilitate the overlapping closure thereof against said flange.