| 摘要 |
<p>An air flow control apparatus is disclosed which is characterized by an essentially zero leakage rate in its closed position, and by minimal air resistance in its open position. The apparatus includes an orifice panel which defines a plurality of troughs of V-shaped cross section, with at least one elongate opening disposed in each trough. A closure is associated with each trough, and includes a pair of pivotally mounted plates which are movable between a spread apart position wherein the plates cover and close the openings in the trough, and a collapsed position wherein the plates are contiguous to each other and spaced from the associated openings to permit free air flow therethrough. A hinge pivotally interconnects the free edges of each pair of plates, and control means is provided for effecting operation of the closures. In one embodiment, the apparatus comprises a damper assembly composed of the orifice panel and closures, and which is removably mounted in a duct so as to facilitate its repair and replacement. In such embodiment the control means includes a plurality of generally circular cams mounted on a pair of rotatable shafts in the duct for operatively engaging the hinges of the closures, to thereby selectively spread apart the pairs of plates. In another embodiment, the apparatus is designed to be permanently mounted in a duct, and the control means for actuating the closure plates includes linkages which are connected to rotatable shafts.</p> |
