Fire damper for ceiling diffuser

A protective damper for controlling the flow of fluid through a ceiling diffuser, the damper comprising:

• a frame defining an opening through which the fluid flows;
• a barrier carried by said frame and having a closed position which prevents the flow of fluid through said opening and an open position which allows the flow of fluid through said opening, said barrier being linearly displaced between its first and second positions;
• an axle rotatably supported by said frame;
• a spring operably coupled with said axle so that said spring exerts a rotational biasing force on said axle;
• an actuator coupled to said axle and adapted to be coupled with a source of power so that said actuator exerts a rotational force on said axle in a direction opposite to said biasing force when said actuator is energized;
• a rigid actuating arm attached to the periphery of said axle;
• a rigid connecting rod pivotally coupled at one of its ends to said actuating arm and coupled at its other end to said barrier;
• and
• wherein said rotational biasing force is converted to a linear biasing force via said actuating arm and said connecting rod so that said barrier is biased into its closed position, and wherein said rotational force exerted by energizing said actuator is converted to a linear force via said actuating arm and said connecting rod to move said barrier to its open position.