Single control tilt drive unit

摘要

A tilt drive unit for a horizontal or vertical venetian blind, operated by a common drive system. The tilt drive unit is designed to keep the blind slats in a titled-open position during extension or retraction of the slats. The tilt drive unit has a tilt roller that is connected to a drive shaft of the blind and has a track formation on its radially outer surface. The track formation has a pair of circumferential linear grooves and a convoluted groove, which can be engaged by a movable tilt member sliding within the grooves. The tilt member is attached to a mechanism for adjusting the angular position of the slats, such as the ends of a ladder cord. The convoluted groove is adapted to induce a translatory movement to the tilt member. The convoluted groove intersects each linear groove at an angled 3-way junction. The tilt member will only move from one of the linear grooves to the convoluted groove after a change of rotational direction of the tilt roller. The tilt member will move from the convoluted groove to one of the linear grooves also at an angled 3-way junction after about a full revolution of the tilt roller in the same direction.