| 摘要 |
A continuous band for use in making spiral seam tubes is made by horizontally aligning sheet metal plates in a common horizontal plane and clamping each adjacent end of the plates separately. A milling cutter is introduced in a slot formed between the adjacent transverse edges of these plates to trim and chamfer these two transverse edges simultaneously. Thereupon at least one of the clamping devices for clamping one of the plates is moved toward the other clamping device holding the other plate so that a welding joint is formed between the two transverse edges, which are then welded together. |
