| 摘要 |
The present invention relates to a device in vertical- moving doors for being able, when a fault has occurred on the door such that its vertical-moving door leaf will fall uncontrollably downwards, to catch the door leaf before it causes damage. The device incorporates a driven member 10, which is set in rotation by the door leaf 1, at least during the downward motion of the latter, and is thereby lent a rotation speed corresponding to the speed of the said downward motion. This driven member 10 is constructed such that, when a rotation speed imparted by the door leaf 1 exceeds a certain limit, it brings a halt to the downward motion of the door leaf 1. <IMAGE> |
