Patent attributes
The invention concerns a fast door, closing an opening provided in a partition, comprising a soft screen (21), means for lifting the screen including, among others, a winding shaft (2) fixed at the door lintel, and a strap (7) whereof one end is fixed to the winding shaft (2) and the other end is fixed to the screen lower edge (8). The invention is characterized in that the strap (7) passes through a tension sensor (6) comprising a mobile element having an opening wherein the strap (7) is engaged, the mobile element being maintained in a first so-called normal operating position by the strap (7), the latter being subjected to a normal operating tension, the mobile element tilting into a so-called abnormal operating position, when the strap (7) shows a tension lower than a predetermined threshold corresponding to an abnormal operation of the door.
