Drive mechanism for door or window cover e.g. blind

摘要

A winding roller (10), mounted horizontally above a door or window opening, has a drive gear pref. on both ends, having a helical gear (14) attached to the roller, and a vertical threaded spindle (16), or optionally a worm or bevel gear. Vertical guides (15) down each side of the opening each contain a helical element (17), eg. a coil spring, coupled to the spindle. Rotation of the roller rotates the spring about its longitudinal axis (17.1). The ends of a horizontal rod (24) at the bottom of the cover are moved vertically by engaging the helical elements (17.2). The helix pitch is chosen to keep the cover stretched between roller and rod. A motor (11) within the roller drives either the roller or the threaded spindle or worm gear.