| 摘要 |
PROBLEM TO BE SOLVED: To alleviate labor when a shutter is opened and to realize opening of the shutter in a short period of time when the shutter is opened/closed by manual operation. SOLUTION: A drum 16 on which a shutter body 11 constructed by arranging a plurality of slats in parallel, is wound, and a pulley 15 which is driven by a cord 2 which is to be manually operated, are installed on a shaft pipe 13 which is a fixed shaft. A clutch member 17 is interposed between a transmission member 19 which is combined with the internal periphery of the drum 16 in one body, and the pulley 15, and as the pulley 15 is rotated, a ball 17a of the clutch member 17 is protruded or withdrawn with respect to the transmission member 19 side, whereby the ball engages with or disengages from a projection. A spring 20 is arranged between the drum 16 and the shaft pipe 13, and when the drum 16 winds down the shutter body 11, energy is stored at the spring 20. On the other hand, when the engagement at the clutch member 17 is cancelled, the spring 20 is released, whereby the drum 16 is rotated in a winding-up direction.
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