Patent ID: 7909226

Claim:
Device for producing a longitudinally welded hollow profile from a sheet metal blank having defined longitudinal edges, the device comprising: at least two tool parts, each tool part having a recess that determines an outer shape of at least one portion of the hollow profile to be produced and each tool part moveable relative to at least one other tool part to change a relative position of the tool parts, a mandrel having an outer shape that determines an inner shape of the hollow profile to be produced, a welding mechanism for welding the longitudinal edges of the sheet metal blank after the sheet metal blank has been shaped to form an open seam profile, a control mechanism that emits control signals for changing the relative position of the tool parts from a mutually distanced starting position into a shaping position, wherein the changing of the relative position occurs in at least two stages, and a holding-down device for holding down the mandrel, wherein the holding-down device is configured to be fed in a direction of the mandrel to form a guide for the longitudinal edges of the sheet metal blank, the holding-down device comprising: a first portion having: two faces that are aligned parallel to each other, and a first thickness between the two faces that determines a first width of a gap of the open seam profile to be formed from the sheet metal blank during a first stage, and a second portion having: two faces that are aligned parallel to each other, and a second thickness between the two faces that determines a second width of the gap of the open seam profile to be formed during a second stage, wherein the second thickness is different than the first thickness.