摘要 |
PROBLEM TO BE SOLVED: To provide a device for preventing rapid unusual descent of a shutter curtain of a shutter device capable of simplifying a structure of a contact part coming into contact with a chain. SOLUTION: A first sprocket wheel 11 is attached to a winding shaft for winding and unwinding the shutter curtain, a second sprocket wheel 12 is attached to a drive device for rotating the winding shaft, and the chain 13 is stretched around these sprocket wheels. A contact member 78 coming into contact with the chain 13 is attached to a turning member 75 of a rotation stop means 70. The contact member 78 is a slide contact part wherein the chain 13 slides and moves while coming into contact with it. The rotation stop means 70 is provided with a spring for turning and biasing the turning member 75 onto a side for engaging a protrusion 75B of the turning member 75 with teeth 11A of the sprocket wheel 11 centered on a central shaft 74. The protrusion 75B being an engaging part is engaged with the teeth 11A by cutting-off of the chain 13. COPYRIGHT: (C)2010,JPO&INPIT
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