Process of manufacturing composite tube by rolling and welding without elongating the same
AssigneePabreco S.A.
InventorGeorges Bujes
Life of this patent
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Abstract
A process for producing multi-layer composite tubes involves extruding an inner plastic tube prior to forming a metallic tube around the inner plastic tube which is subsequently covered with an outer plastic layer. The metallic tube is initially formed to have an inner diameter which is substantially greater than the outer diameter of the inner plastic tube. Subsequent to welding to seal the metallic sheet into the form of a tube, the excess diameter of the metallic tube is reduced in a manner which avoids stretching or elongating the tube. Adhesive coatings can be applied between the various constituent layers of tubes, and a mesh can be interposed between the metallic tube and the outer plastic layer.
Claims58
A process for producing multi-layer composite tubes including a metal tube component by a method wherein elongation of the metal tube is avoided, comprising the steps of:
- (a) providing a first tube with a predetermined outer diameter defined by an outer surface of the tube;
- (b) forming a metal tube with an inner surface surrounding said first tube with said metal tube, said metal tube having an inner diameter sufficiently greater than said predetermined outer diameter so that space exists between said outer surface of the first tube and said inner surface of the metal tube around at least a portion of said first tube;
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- (c) reducing said inner diameter of said metal tube so that said inner surface of said metal tube contacts said outer surface of the first tube by applying a force against said metal tube without elongating said metal tube.
A process for producing multi-layer composite tubes including a metal component by a method in which the metal tube is shaped at a sizing station, the method comprising the steps of:
- (a) providing a first tube with a predetermined outer diameter defined by an outer surface of the tube;
- (b) forming a metal tube with an inner surface surrounding said first tube with said metal tube said metal tube having an inner diameter sufficiently greater than said predetermined outer diameter so that space exists between said outer surface of the first tube and said inner surface of the metal tube around at least a portion of said first tube;
- (c) advancing said metal tube along a production line by utilizing a first plurality of driving elements positioned upstream of the sizing station and at least one further driving element positioned downstream of the sizing station, by driving said first plurality of driving elements at a first velocity and said at least one further driving element at a second velocity, wherein said second velocity is no greater than said first velocity, thereby driving said metal tube in accordance with said velocities;
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- (d) pressing said metal tube at the sizing station so that said inner surface of said metal tube contacts said outer surface of the first tube without elongation of said metal tube.
Dependencies are inferred from the claim text.