Process and tubular-bag machine for forming a longitudinal welding or sealing seam on the casing of a foil tube

摘要

A process for forming a longitudinal welding or sealing seam on the casing of a foil tube and a tubular-bag machine for carrying out this process are described. The process is characterised in that the welding or sealing head is driven so that it executes an arcuate movement from the first vertex to the second vertex of its path of movement, and in that the overstroke of the segment of the path of movement of the welding or sealing head relative to the foil tube between the initial point and final point of contact with the latter is compensated by a displacement in length of the connecting devices between the drive and the welding or sealing head. The corresponding drive is achieved by means of an articulated coupling mechanism which imparts the desired arcuate movement in the welding or sealing head and which is assigned connecting devices of variable length for connection to the welding or sealing head. A particularly exact movement of the welding or sealing head onto the foil tube is achieved by means of this method and by means of this machine. <IMAGE>