Method of moving a roller blind at a controlled rate along an ascending or descending path and associated drive system

摘要

Drive system (10) for a roller blind, sun canopy or the like, comprising motor means (12) which can move the roller blind along an ascending or descending path, in which during the upward movement the weight force of the roller shutter produces an opposite torque to the torque supplied by the motor (12), whereas during the downward movement the two pairs match, and comprising braking means (16, 20) that can slow the shutter roller during upward and downward movement, said braking means (16, 20) adapted to be held stationary when the roller shutter shaft (12) is stationary being; said braking means (16, 20) adapted to maintain the braking action also during the upward movement of the roller blind, without being that during activation of the motor (12) the braking action of the braking means (16, 20 ) is sufficient to interrupt / stop the movement of the roller blind; characterized in that said braking means (16, 20) comprise a disc rotary friction (16) forming a seat for a braking ring (20), said seat comprising a disc circular holding (30) within which is placed the braking ring (20), said drive rotary friction (16) being pushed by elastic means (14) towards the fixed surface of a disc intermeshing (18), which is fixed to a cage (24 ).