Patent ID: 8783325

Claim:
Longitudinal continuous welding device for packaging machines comprising: one supporting piece ( 1 ) for layers of material to be welded continuously; at least one ultrasonic welder ( 2 ) equipped with a sonotrode ( 21 ), and wherein the sonotrode ( 21 ) and the supporting piece ( 1 ) face each other horizontally, arranged on opposite sides of a longitudinal path along which the layers of material (M) to be welded continuously advance inside the packaging machine, wherein both the at least one ultrasonic welder ( 2 ) and the supporting piece ( 1 ) are unable to move in the direction of longitudinal movement of the layers of material (M); at least one positioning element ( 3 ) to arrange the welding device in a non-operating position, in which the sonotrode ( 21 ) of the welder and the supporting piece ( 1 ) remain distanced horizontally, or in an operating position for welding in which the sonotrode ( 21 ) and the supporting piece ( 1 ) are maintained very close to each other; and at least one elastic pusher ( 4 ), which acts on at least one of the ultrasonic welder ( 2 ) and the supporting piece ( 1 ) to push them against the opposite sides of the layers of material (M) to be welded continuously; wherein said at least one elastic pusher ( 4 ) is configured and arranged to enable the separation between the ultrasonic welder ( 2 ) and the supporting piece ( 1 ) to vary at a very high frequency, due to the action of the sonotrode ( 21 ), enabling the layers of material (M) to be welded to continuously advance through the space between the supporting piece ( 1 ) and the sonotrode ( 21 ) as these conduct the welding of the layers of material (M).