Fire damper
AssigneeDaito Tech Kabushiki Kaisha
InventorKatsuyoshi Nakagawa
Life of this patent
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Abstract
A fire damper having a duct, a flap rotatable about an axis crossing the duct, an engaging member, and a spring ordinarily urging the flap to rotate in a direction. The fire damper has a trigger mechanism comprising a leaf spring fixed to the flap and having a free end engageable with the engaging member so as to stop the flap at an angle parallel with air flow. The fire damper further has a heat detecting and actuating member made of form memory alloy spring which has an end fixed with the flap and has another end fixed to the leaf spring at a position near the free end of the leaf spring.
Claims5
A fire damper comprising:
- a duct;
- a flap provided in the duct and supported by the duct in a rotatable manner about an axis crossing the duct and urged elastically in a rotating direction;
- a leaf spring an end of which is fixed to the flap;
- an engaging member capable of engaging with the leaf spring so as to stop rotation of the flap;
- and
- a heat detecting and actuating element made of form memory alloy which has an end fixed with the flap and has another end fixed to the leaf spring at a position near a free end thereof so that the member deforms the leaf spring when the member shrinks under heating.
Dependencies are inferred from the claim text.