Welding apparatus for a packaging machine

Claim 1

Welding apparatus for a packaging machine in which the longitudinal edges of a moving web of packaging material are welded for creating a flexible tube from which the finished packages are formed, in which hot air can be led into the gap between the longitudinal edges of the packaging material preformed into a flexible tube and provided with pressure-applying means for welding together the portions of the web extending along the longitudinal edges and heated by the hot air, characterized by a hood to bring up the hot air having an opening surrounded by wall portions and directed on to the portions of each edge of the flexible tube to be welded and whose wall portions are shaped in such a way that the opening is located in the immediate area of the external surface of the pre-formed flexible tube and with the opening in the hood extending at least over the side edges of the web to be welded in the peripheral direction of the flexible tube, said hood being subdivided by means of partitions extending in the direction of travel of the flexible tube, which partitions forms a chamber opening in nozzle-like manner towards the gap between the longitudinal edges of the flexible tube and communicating with the hot air supply, and in that together with the wall portions of the hood the partitions form additional side chambers.