Abstract: A device for automatically releasing the braking mechanism of roller blinds or shutters or the like which are selectively operated by a motor drivingly connected to the drum of the blind wherein a drive shaft for the drum is prevented from rotating by gripping a brake disk between two rotating plates. Releasing of the brake is automatically effected as soon as the motor is activated by magnetic attraction of a yoke, which includes one of the rotating plates, against a spring element. In the event of an electrical failure, the brake may be released manually by mechanically urging the yoke from the brake disk against the action of the spring element.

Abstract: A two-speed reducing mechanism for controlling the adjustment of a closure such as a blind having adjustable slats which includes a drive input shaft or wheel which is meshed with a planetary ger system supported by an output drive ring which itself is oriented within a rotatable bushing which may be selectively secured from rotation by a braking device. The planetary gear assembly is also meshed with the bushing so that when the bushing is rotatable, the closure member may be quickly adjusted in a one-to-one drive relationship with respect to the input shaft, however, when the bushing is prevented from rotating, the elements of the planetary gear assembly will rotate upon themselves causing a speed reduction.