| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric-powered shutter which is operated at high speed for winding up the shutter from its beginning and at low speed for lowering the shutter. SOLUTION: A clutch mechanism 100 which is put in engagement only when turning a take-up shaft 2 in the direction of winding up a shutter curtain 1 is provided at a driven sprocket 11 in a small diameter being linked to a driving sprocket 10 at one side and made to serve as a ascent drive system for winding up the shutter curtain 1 at high speed from the beginning. And the clutch mechanism 100 which is put in engagement only when turning the take-up shaft 2 in the direction of lowering the shutter curtain 1 is provided at a driving sprocket 20 linked to a driven sprocket 21 in a large diameter and made to serve as a descent drive system for lowering the shutter curtain 1 at a low speed.
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