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US 3,990,464 AGranted
Heat-responsive duct closing method and apparatus
OwnerJames H. Jenkinsinventor
Life of this patent
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Abstract
A method and apparatus are disclosed for controlling the passage of air, smoke and noxious fumes through the heating and ventilating ducts of a building by means of a normally-collapsed, leak-proof bag which expands upon activation by smoke detection means to completely seal the duct from the passage of air and smoke.
Claims14
The method of closing a heating and ventilating duct upon the occurrence of fire to prevent the flow of a gas through the duct, which comprises the steps of:
- a. arranging within the duct an impervious inflatable bag in the collapsed condition;
- b. connecting the bag with normally de-activated bag inflating means;
- and
- c. activating said bag inflating means when the temperature of the fluid in said duct exceeds a given value to expand said bag to an expanded condition in sealed engagement with the entire inner circumference of a portion of the duct, thereby to prevent the flow of fluid through the duct.
1 more element
Apparatus for sealing a duct of a building upon the occurrence of a fire, comprising
- a. an inflatable impervious bag adapted for mounting in the collapsed condition within the duct;
- b. normally de-activated bag inflating means connected with said bag;
- and
- c. heat-responsive activating means for activating said bag inflating means to expand said bag to an expanded condition in sealed engagement with the entire inner circumference of a portion of the duct, thereby to prevent the flow of fluid through the duct.
1 more element
Dependencies are inferred from the claim text.