DRIVING MECHANISM FOR A WINDING SHAFT OF AN ARCHITECTURAL COVERING AND IMPROVED ARCHITECTURAL COVERING

摘要

A driving mechanism (13) for a winding shaft (3) of an architectural covering (1) that is adapted to be associated with a fixed architectural mounting structure. The driving mechanism (13) includes a driving member (23), and a driven member (21) for inducing rotation to the winding shaft (3) of the architectural covering (1). A torque limiting clutch (57) is operatively engaged between the driving member (23) and the driven member (21) and a non- rotatable stationary member (51) for mounting of the driven member (21) to said fixed mounting structure. A first limit stop (85) is associated with the non- rotatable stationary member (51) and a second limit stop (87) on the driven member (21) is adapted to be engaged by the first limit stop (85) only after a predefined number of rotations of the driven member (21) from a first rotational end position to a second rotational end position. A lost motion mechanism (79, 81) is interposed between the driven member (21) and the stationary member (51) to allow the predefined number of rotations of the driven member (21) from the first to the second rotational end position and vice versa. The stationary member (51) is locked with respect to the fixed mounting structure by a locking tab (37), but can be unlocked for rotation with the driven member (21) by disengaging the locking tab (37).