| 摘要 |
<p>A utility door for opening and closing an opening in a wall, comprising a flexible curtain (1), said opening being closed when the curtain is extended and open when the curtain is bunched up on one side of the opening. On said side of the opening, the door comprises a curtain winding shaft or straps for folding and moving the curtain, the winding shaft is rotated by an electric motor, and the curtain has one edge attached to the shaft or adjacent thereto, and an opposite movable free edge. Said door comprises a safety system including at least one elongate element such as a strap capable of being wound around the winding shaft together with said curtain or said straps while one end of said strap is substantially attached to the free curtain edge, as well as means for delivering a signal when the tension in the strap (10) falls below a predetermined threshold.</p> |
