Patent ID: 6494360
Filing Date: 2002-12-17
Classification: B21C,B21D

Abstract:
A process to produce a straight bead welded tube from a flat sheet metal blank having an inside and an outside, wherein the outside is constituted by parallel longitudinal edges, comprising:shaping the flat sheet metal blank into a slotted tube by means of a first and a second of two tool halves constituting a form tool, each of the two tool halves having an outer cylindrical half shell and an internal cylindrical mandrel half fixed to the outer cylindrical half shell to produce a first and a second form gap, each of said two tool halves being disposed laterally inverted in relation to one another, wherein the first of the two tool halves moves toward the second of the two tool halves; and welding the longitudinal edges of the flat sheet metal blank to one another, wherein said longitudinal edges emerge exposed at a top of the form tool, to produce the straight bead welded tube at the top of the form tool, wherein during shaping the longitudinal edges are retained in position by the two form tool halves while the inside of the sheet metal blank is held by the internal cylindrical mandrel halves cooperating with the outer cylindrical half shells to produce the first and the second form gap.