Patent ID: 7566264

Claim:
A damper for controlling the flow of air through high velocity ductwork, the damper comprising: a damper housing having at least a first side wall enclosing an interior region conveying the laminar flow of high velocity air, the at least a first side wall including first and second side wall end sections at first and second ends of the damper housing, and an expanded side wall section that is spaced outwardly from the first and second side wall end sections and that defines a recessed portion having recessed portion ends that are bounded by a transition region comprised of two edges outwardly inclined with respect to the first and second side wall end sections, wherein the first and second ends are adapted for insertion into associated high velocity ductwork respectively; and, a collar-shaped fillable bladder received within the at least a first side wall facilitating the laminar flow of high velocity air, wherein the collar-shaped fillable bladder defines an enclosed volume and is adapted to expand when filled with an associated medium for substantially closing the interior region from conveying high velocity air; and, wherein the collar-shaped fillable bladder is adapted to retract into the recessed portion creating a substantially flush surface with respect to the interior of the first and second side wall end sections facilitating the laminar flow of high velocity air through the damper.