Process for producing longitudinally welded tubes
AssigneeNexans
InventorsKlaus Porcher, Friedrich Harten
Life of this patent
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Abstract
In a process for producing longitudinally welded tubes, a metal strip, which is continuously pulled from a supply, is gradually formed into a slit tube and the longitudinal slit of said slit tube is welded. The metal strip (2) is pulled through a plurality of drawing dies (8, 9, 10, 11) arranged one behind the other and having a diameter that decreases in production direction, and in each of the drawing dies (8, 9, 10, 11) is increasingly bent in circumferential direction. The slit tube is closed in a last forming step (15) immediately in front of the welding point.
Claims15
Process for producing longitudinally welded tubes in which a metal strip continuously pulled from a supply is gradually formed into a slit tube and the longitudinal slit of the slit tube is welded, characterized in that the metal strip (2) is pulled from the supply directly through a plurality of drawing dies (8, 9, 10, 11) arranged one behind the other with decreasing diameter bores in a production direction, the metal strip (2) is increasingly bent in circumferential direction in each of the bores of the drawing dies (8, 9, 10, 11), and in a last forming step (15) the slit tube is closed immediately in front of the welding point.
Apparatus for producing longitudinally welded metal tubes comprising:
- a shaping device for shaping a metal strip into a slit tube in several steps;
- and
- a welding device for closing the longitudinal slit of the tube,
- wherein the shaping device (3) comprises a plurality of drawing dies (8, 9, 10, 11) arranged one behind the other, which incrementally bend the metal strip (2) into a slit tube,
- wherein the plurality of dies each contains a bore therein for receiving the metal strip.
Apparatus for producing longitudinally welded metal tubes comprising:
- a shaping device for shaping a metal strip into a slit tube in several steps;
- and
- a welding device for closing the longitudinal slit of the tube,
- wherein the shaping device (3) comprises a plurality of drawing dies (8, 9, 10, 11) arranged one behind the other, which incrementally bend the metal strip (2) into a slit tube,
- wherein the plurality of dies each contains a bore therein for receiving the metal strip,
- characterized in that in front of the last drawing die (15) a sword (14) is provided, which protrudes into the interior of the slit tube and guides the strip edges.
Dependencies are inferred from the claim text.