Machine and method for packaging articles

A machine for packaging articles comprising:

• a fixed frame;
• a feeding device for feeding a film to a packaging station, where the film is used to wrap the articles,
• a conveyor line by which the articles are directed to the packaging station;
• a sealing unit, located in the packaging station, movable relative to the fixed frame and also comprising two sealing elements movable relative to each other between a spaced-apart position and a close-together position where the two sealing elements cooperate to seal the film interposed between the two sealing elements;
• a first movement device for moving the sealing unit and comprising a first motor fixed to the fixed frame;
• a second movement device for moving the sealing unit and comprising a second motor fixed to the fixed frame, the second motor being operatively coupled to at least one of the two sealing elements,
• wherein the first movement device comprises a first articulated arm and the second movement device comprises a second articulated arm;
• a control unit operatively connected to the first motor and to the second motor in order to drive the first motor and second motor in a predetermined relationship to move the two sealing elements relative to each other and relative to the fixed frame;
• wherein the sealing unit comprises a movable frame which is movable, relative to the fixed frame, along a feed direction of the articles and which carries the two sealing elements;
• wherein the second movement device comprises a rocker hinged to the movable frame to rotate with respect to the movable frame about a pivot point,
• wherein the second articulated arm comprises a first member and a second member which are movable relative to each other, the first member being connected to the second motor to be carried in rotation and the second member being hinged to the rocker at a position different from the pivot point, so that the rocker is carried in rotation relative to the movable frame and about the pivot point,
• the rocker being coupled to at least one of the two sealing elements in order to move the two sealing elements from the spaced-apart position to the close-together position and vice versa,
• wherein the second movement device comprises a first rod which is operatively coupled to a first sealing element of the two sealing elements and to the rocker to move the first sealing element when the rocker is carried in rotation about the pivot point, and a second rod which is operatively coupled to a second sealing element of the two sealing elements and to the rocker to move the second sealing element when the rocker is carried in rotation about the pivot point;
• wherein the second movement device comprises a guide associated with the movable frame to guide the movement of the first and second sealing elements relative to each other;
• wherein the first motor is driven in a first rotation direction to move the movable frame in a first direction along a predetermined axis of movement parallel to the feed direction, and the first motor is driven in a second rotation direction, opposite to the first rotation direction, to move the movable frame along the predetermined axis of movement in a second direction opposite to the first direction;
• and
• wherein the second motor is driven in a third rotation direction to move the sealing elements from the spaced-apart position to the close-together position, and the second motor is driven in a fourth rotation direction to move the sealing elements from the close-together position to the spaced-apart position;
• wherein the first motor is an electric motor, having a rotatable first shaft and the second motor is an electric motor having a rotatable second shaft;
• wherein the first articulated arm comprises a first member and a second member of fixed length hinged to each other, the first member of the first articulated arm being fixedly connected to the first shaft and the second member of the first articulated arm being rotatably attached to the movable frame;
• wherein the first member and the second member of the second articulated arm are of fixed length and the first member of the second articulated arm is fixedly connected to the second shaft.