摘要 |
The system (10) comprises: an actuator or motor (14) adapted to be secured to a wall (P); and a rotatable element (16) adapted to be constrained to a leaf (A) and to be rotated about an actuation axis (X-X) by means of the actuator or motor (14), in such a way as to move the leaf (A) in order to open and/or close an opening (F). The system further comprises disengageable transmission means (18), which comprise a drive portion (20) and a driven portion (22) rotatably cooperating with the actuator or motor (14) and with the rotatable element (16), respectively, and which can be placed in: a disengaged condition, wherein they are rotatably independent of each other and movable among a plurality or predetermined mutual arrangements, each one of the mutual arrangements corresponding to an associated angular position that can be taken by the leaf (A) with respect to the opening (F); and an engaged condition, wherein they rotatably cooperate together and are locked into a mutual arrangement which can be selected among the plurality of predetermined mutual arrangements. |