Welding machine for foil webs

Abstract

A welding machine for foil webs which are overlapped comprises an undercarriage which includes a rectangular frame having longitudinal frame members and laterally adjustable transverse frame members with wheels supporting the frame. A welding device is positioned on the frame and it in the frame includes centering elements which may be adjustable so as to position the welding device accurately in respect to the frame. The welding device itself advantageously includes slots extending inwardly from each side into which a respective foil end is positioned and roller means which engage with one of the foils for guiding it as the undercarriage is moved over the top of the respective foils to be welded together. The undercarriage during the welding device includes a drive from the wheels to the rollers which includes a shaft assembly having a plurality of universal joints. The front of the undercarriage carries a guide which projects forwardly thereof and the front edge of the welding machine includes a caster which is engageable with a wall element in the event that the device is to be used for vertical welding. By the arrangement of two rollers on at least one pivotable roller carrier these rollers can always jointly adapt themselves to any unevennesses of the terrain, so that the rollers correlate with one another in pairs take support on the foil strips with substantially equal contact force both in the case of level and of uneven supports. In this manner a uniform and direction-stable forward movement is obtained.