Abstract: An apparatus for perforating a packaging film comprises at least one rotary cutter, which is rotationally driven by suitable drive means, and a fixed cutter, the cutters having respective blades by which a packaging film moving between the knives themselves on a supporting surface is perforated at regular intervals. The rotary knife is rotated by drive means which move it at a controlled speed of rotation that varies within one full angular revolution.

Abstract: An apparatus for automatically controlling the work flow of a machine—equipped with effectors (2) driven by rotational motors (12)—comprises: electronic storage means (11) having resident functions that relate the angle of rotation described by a controlling motor (12) with the desired instantaneous position of a controlled effector (2); means (13) for detecting the actual instantaneous position of the controlled effector (2); comparator means (14) for determining the positional error of the controlled effector (2) relative to a given expected position upon reaching a certain angle of rotation of the controlling motor (12); and means (15a) for controlling the motor (12) of the controlled effector (2), which receive the error signal from the comparator means (14) and apply to the motor (12) a corresponding corrective action designed to control and synchronize the angular position of the controlled motor (12) with that of the controlling motor (12).

Abstract: An apparatus for automatically controlling the work flow of a machine—equipped with effectors (2) driven by rotational motors (12)—comprises: electronic storage means (11) having resident functions that relate the angle of rotation described by a controlling motor (12) with the desired instantaneous position of a controlled effector (2); means (13) for detecting the actual instantaneous position of the controlled effector (2); comparator means (14) for determining the positional error of the controlled effector (2) relative to a given expected position upon reaching a certain angle of rotation of the controlling motor (12); and means (15a) for controlling the motor (12) of the controlled effector (2), which receive the error signal from the comparator means (14) and apply to the motor (12) a corresponding corrective action designed to control and synchronize the angular position of the controlled motor (12) with that of the controlling motor (12).