End seal for damper blades

Ventilation systems use dampers to control the flow of air through conduits. The dampers are opened or closed to allow or prevent the flow of air. Typically, dampers extend across the entire duct and have blades tilting between an open and closed position. In the closed position, the blades contact one another to form a seal across the duct.

When the blades are pivoted to their closed position, it is possible to create an effective seal as the blades overlap one another to prevent the passage of air. A larger problem is preventing air flow between the blades and the frame in which they are held. Previous patents have addressed this problem by placing a seal along the side of the frame which engage the blades when in the closed position. U.S. Pat. No. 4,241,539 to Josephson discloses a curved relatively rigid side seal strip having a plurality of teeth. The pivoted blades are sealed by the teeth when the blades are in the closed position. U.S. Pat. No. 3,718,081 to Root discloses a damper having a sealing strip formed by a synthetic resin material. The sealing strip is discontinuous along the edge of the frame for creating a seal between the blades and the frame. Caming et al., in U.S. Pat. No. 3,783,768, discloses seals running along the length of the blades that engage one another when the blades are in their overlapped, closed configuration. Additional seals extend from the top and bottom of the frame to engage the blades and form a seal.

It is an object of the invention to provide a seal between the blades and frame of a damper.

It is another object of the invention to provide seals on a damper blade which are easily replaced if needed.

It is another object of the invention to provide seals for a damper effectively blocking air flow when the damper is closed.

These and other objects of the invention would be apparent to one of ordinary skill in the art after reading the disclosure of the invention.

End caps are attached to the end of each blade of a damper. When in the closed position, the end caps seal the space between the blade and frame. Sealing fins may extend from the end cap to further enhance the sealing capability. The end caps are easily replaced if worn and effectively prevent air from flowing between the frame and end of the blades.

A damper 10 is shown in FIG. 1 with a frame 12 holding a plurality of blades 14. The blades can be moved from an open to closed position by rotation of the control shaft 16 and the linkage 18 extending between the blades.

The end view of a blade is depicted in FIG. 2. The blade has lever 19, connecting with the linkage 18 to affect pivoting motion of the blade. The blade has a front and back side spaced from one another. The end seal traverses the distance between the front and back sides and is best described with reference to FIG. 3.

The end caps have a size and shape corresponding to the profile of the blade end. The caps are made of any suitable material, preferably a soft resilient material such as natural or synthetic rubber or a polymer. The caps may be secured to the blade end in any suitable manner. At least one end, but preferable both ends, of the blade are provided with end caps. One such attachment method is the use of bosses 22, frictionally fitting within the space between the front and back surfaces of the blade. The outwardly facing surface of the end caps may be provided with flexible sealing fins 24. The flexibility of the fins enhances the fit between the cap and frame.