| 摘要 |
Two abutting edges of two sheets, or one sheet where, for example, a tubular member is to be formed, each has an edge portion formed in a U-shaped section so that the edges can be placed end on with the U-shape of one 90 DEG out of alignment with and enclosed within the U-shape of the other. These U-shaped sections enclosed one within the other are fed successively to four pair of rotatable profiled deforming rollers which successively fold the arms and bases of the U-shaped sections over one another to produce a joint between the sheets, or on the sheet, in which the base and arm positions of one 'U' are aligned with one arm and the base portion of the other 'U'. |
