| 摘要 |
PURPOSE:To enable complete closing of a dampler with an inexpensive structure by elastically slidably rotating one end of the damper with the rugged circularly- arcuate surface of a rotation control member provided at one side in a duct and intimately contacting the other of the damper with the step provided at other side in the duct. CONSTITUTION:A rotaion control member 13b having a rugged circularly-arcuate surface 13a around a rotational shaft 12 of a damper 11 as a center is mounted at the top side of a duct 10 of square cylindrical shape via a pin 13b at the top side of the duct 10. A step 10a which contacts at the periphery lower than the shaft 12 of the damper 11 with the lower side of the duct 10 upon closing. The end of the damper 11 is formed with a thin part 11a having elasticity in such a manner that the circular-arc for connecting the valleys 13a' of the surface 13a is slightly smaller than the circular arc 14 of rotation at the end of the thin part 11a and the circular-arc for connecting the tops 13a'' is further smaller than that. In this manner, the thin part 11a is stepwisely rotated while bending at the time of rotating the damper 11, thereby adjusting the opening, and the is sealed in contact with the step 10a at the lower part of the damper upon closing. |
