Anti-jamming safety device for a curtain-type door having reinforcing bars

A vertically-raisable door of the curtain type for industrial use and including a curtain for closing a door-bay, and being reinforced by bars whose ends are guided in slideways, each slideway comprising a web, a first guide wall against which the curtain is pressed when in a down position, and a second guide wall, said slideways forming lateral uprights of a door-frame surrounding the door-bay, the width of each slideway being reduced at its bottom end by means of a filler component received inside the slideway against the web of the slideway and against said second guide wall, said component having a clearance surface (23) facing the door-bay, and a guide ramp comprising an upper guide surface (21) and a placement surface (24) facing said first guide wall of the slideway and sloping down towards said first guide wall to co-operate with said first guide wall to delimit a placement volume that tapers downwards, wherein the clearance surface slopes from the bottom towards the web of the slideway at an angle (A) lying in a range from about 1.degree. to about 10.degree. such that the horizontal distance between the clearance surfaces of the two slideways in the two facing vertical lateral uprights increases going upwards.