| 摘要 |
<p>The present invention relates to a device for keeping constant air volume, which comprises: a hollow cylindrical body (100); a moving member (300) having one or more doughnut-shaped wings (310) having the same pivot, a center portion (330) formed with an insertion hole at the position of the pivot, and a guide (320) for connecting the wings (310) to the center portion (330); a shifted gear (400) having a gear-tooth portion (410) formed in the screw thread shape outside to be inserted into the insertion hole of the center portion (330) of the moving member (300) through engagement and a hollow portion (420) formed inside; a shaft (500) penetratingly inserted into the hollow portion (420) of the moving gear (400), and fixed in accordance with a line which connects the centers of the top surface and the bottom surface of the body; an elastic member (600) for applying a stronger elastic force to the moving gear (400) as the moving gear (400) moves to the bottom surface of the body (100) more closely; and a cap (200) fixed to the body (100), and having a hollow portion (220) inside to be inserted by the center portion (330) of the moving member (300) and the moving gear (400), and a guide groove (230) formed in a side surface for defining the movement path of the guide (320) of the moving member (300).</p> |
