摘要 |
A method of forming a seam joining two workpieces, such as thermoplastic shoe parts, by supporting said parts with the edges to be seamed in adjacent relationship on a support surface having a grooved-out portion aligned with the edges to be seamed, forming a weld along said adjacent edges, flowing a portion of the weldment into the grooved-out portion during welding, thereby forming a reinforcing rib aligned with and superimposed over the seam joining said workpieces and apparatus for use in practising the method. |