Patent ID: 7591298

Claim:
An on-failure blind stopper system for a blind in which a lifting/lowering cord that vertically moves in response to rotation of a rotation shaft in a head box has a lower end hanging from the head box and connected to a bottom part disposed at the bottom of shielding member(s), and the shielding member is lifted or lowered by lifting or lowering the bottom part by the lifting/lowering cord, the on-failure blind stopper system comprising on-failure stopper assembly that stops rotation of the rotation shaft when a failure occurs in lifting or lowering of the bottom part, wherein said on-failure stopper assembly comprises a restriction member that is vertically movable in the head box, and the restriction member through which the rotation shaft passes is pressed by the lifting/lowering cord and prevented from moving upward or downward to permit the rotation shaft to rotate when the lifting/lowering cord is under tension and moves upward or downward to engage with the rotation shaft to prevent the rotation of the rotation shaft when the lifting/lowering cord sags.