Damper having a plurality of blade assemblies

A damper comprising:

• a frame;
• at least one first blade assembly and at least one second blade assembly disposed next to one another and rotatably supported by the frame, the at least one first blade assembly and the at least one second blade assembly being rotatable together about respective blade rotation axes between an open position and a closed position,
• each of the at least one first blade assembly and each of the at least one second blade assembly having:
• a first end portion and a second end portion;
• a first end provided at the first end portion;
• and
• a second end provided at the second end portion,
• in response to the at least one first blade assembly and the at least one second blade assembly being in the open position:
• the at least one first blade assembly and the at least one second blade assembly being spaced apart to permit gas flow through the damper,
• the first end portion of the at least one first blade assembly and the first end portion of the at least one second blade assembly are on a first side of the blade rotation axes, and
• the second end portion of the at least one first blade assembly and the second end portion of the at least one second blade assembly are on a second side of the blade rotation axes,
• the at least one first blade assembly comprising:
• a shaft rotatably supported by the frame, the shaft defining the blade rotation axis of the at least one first blade assembly;
• a first blade connected to the shaft;
• a second blade connected to the shaft, the shaft being disposed between the first and second blades, the first and second blades being connected to one another;
• and
• a flexible blade extension disposed at the first end portion of the at least one first blade assembly, the flexible blade extension being held between the first and second blades and extending from the first and second blades, the flexible blade extension being configured to flex in response to the a transverse load being applied to the flexible blade extension upon the first end portion contacting the second end portion of the at least one second blade assembly in response to the at least one first blade assembly and the at least one second blade assembly being in the closed position;
• and
• a first seal member disposed at the first end of the at least one first blade assembly, the first seal member of the at least one first blade assembly being connected to an end of the flexible blade extension of the at least one first blade assembly, the flexible blade extension of the at least one first blade assembly connecting the first seal member of the at least one first blade assembly to the first and second blades of the at least one first blade assembly;
• the at least one second blade assembly comprising:
• a shaft rotatably supported by the frame, the shaft of the at least one second blade assembly defining the blade rotation axis of the at least one second blade assembly;
• a first blade connected to the shaft of the at least one second blade assembly;
• a second blade connected to the shaft of the at least one second blade assembly, the shaft of the at least one second blade assembly being disposed between the first and second blades of the at least one second blade assembly, the first and second blades of the at least one second blade assembly being connected to one another;
• and
• a second seal member disposed at the second end of the at least one second blade assembly,
• each of the first and second seal members of the least one first blade assembly and the at least one second blade assembly has a rounded contact portion,
• in response to the at least one first blade assembly and the at least one second blade assembly being in the closed position:
• the first end portion of the at least one first blade assembly is in contact with the second end portion of the at least one second blade assembly to restrict gas flow through the damper;
• the first seal member of the at least one first blade assembly abuts the second end portion of the at least one second blade assembly at a first contact point to form a seal between the at least one first blade assembly and the at least one second blade assembly at the first contact point;
• the second seal member of the at least one second blade assembly abuts the first end portion of the at least one first blade assembly at a second contact point to form an other seal between the at least one first blade assembly and the at least one second blade assembly at the second contact point;
• the rounded contact portion of the seal member of the at least one first blade assembly abuts the second end portion of the at least one second blade assembly;
• and
• the rounded contact portion of the seal member of the at least one second blade assembly abuts the first end portion of the at least one first blade assembly.