Roller blind winding drum with spring aided return - has counter pulley fixed via spiral spring to hub

摘要

The roller blind winding drum (2) with spring assisted blind return rotation, is the type with belt (8) and pulley (7) transmission, and has the counter pulley (19) providing recoil mounted on the drum axle co-axial and adjacent to the drive pulley (7). Pref. the counter pulley is mounted free to rotate on a static hub within which the drum and drive pulley axle also rotates, and a spiral spring locating within the counter pulley's hollow body is fixed to the fixed hub and internal drum periphery. The belt (8) is thus wound round the drive pulley (7), traverses a return block (12) on the blind (1) foot, and returns to wind around the counter pulley (19), effecting automatic spiral spring loading as the blind descends.