Patent ID: 7775255

Claim:
Darkening device, comprising: a shade made of a length of fabric material which is mounted to be movable between a receiving position in which it is taken up spaced apart from a region to be darkened, and a drawn position in which it extends underneath the region to be darkened, and supporting means for supporting the shade in a transverse direction in the region to be darkened, wherein the supporting means holds only areas near side edges of the shade fabric material at a portion of the shade fabric material that is longitudinally intermediate ends thereof and wherein the supporting means tensions the shade between the side edges by applying a stretching the force to the shade fabric material in said transverse direction, and wherein the supporting means comprises at least a pair of sliding blocks permanently connected essentially opposite each other on the side edges of the shade, a guide rail located on each side of the region to be darkened, wherein each of the sliding blocks slidably interacts with a respective guide rail in a lengthwise direction of the guide rails and in a transverse direction of the guide rails, and wherein the supporting means have elastic return means which entrain each sliding block in a sliding motion in the transverse direction to the outside.