Utility door with a safety system

A goods-handling door for opening and closing a bay in a wall, the door including a flexible curtain, said bay being closed off when the curtain is deployed, and open when the curtain is gathered up on an edge of the bay, the door including a rolling-up shaft on said edge of the bay for receiving said curtain, the rolling-up shaft being rotated by an electric motor, said curtain having an edge fixed to said shaft and having a displaceable free opposite edge, said door being characterized in that it includes a safety system including:

• a safety strap disposed along the curtain perpendicular to the rolling-up shaft, one end of said safety strap being fixed to the rolling-up shaft, and said safety strap being capable of being rolled up with the curtain on said rolling-up shaft between the rolled-up turns of the curtain, the other end of said safety strap being fixed to the curtain adjacent the free edge of the curtain;
• and
• a signal-emitting means for emitting a signal when the tension of the safety strap drops below a predetermined threshold.