| 摘要 |
Appts. for joining wall parts of tubes with a transverse welded seam by means of opposite welding jaws moving along a closed path, has folders which are moved in the direction of the tube supply, at least during the period of time they operate on the tube, so that they always remain aligned with the welding jaws. The folders and the welding jaws remain accurately aligned during the welding operation, so that high quality welded seams are obtd., even with thick plastic material. |
