| 摘要 |
<p>The present invention relates to a kind of roller shutter structure which can be retracted or set free up and down. It includes a support, a curtain and draw line. The upside of the curtain is fixed on the support. The drawing end of draw line passes through a limited slip machine fixed on the support. The another end of draw line strides to another end of the curtain from the underpart of the curtain, and it is connected with a cone. The slender end of the cone is embedded in a through hole of a fastener fixed on the support, and the thick end of the cone is clipped at the end of the through hole. An open slot is provided on the fastener along the lateral margin of the through hole and connected with the through hole. Location end of the draw line is connected with the cone, and the draw line is located by the cone and the fastener. When the outside force on the draw line exceeds 3 KGs, the cone can be automatically off with the fastener due to expanding of the through hole. Its structure is simple and secure.</p> |
