APPARATUS AND METHOD FOR PRODUCING A TUBE OF VARYING CROSS-SECTION

摘要

An apparatus for producing a tube having a round cross-section over a major portion of its length and intermediate its ends having a flattened oval cross-section. The apparatus includes an extrusion head with an extrusion die through which the tube is extruded. A pinching device, which includes opposed pinching elements, is arranged at the extrusion head so as to be selectively moveable together to press on and pinch the tube to produce the oval cross-section of the tube. The rollers are selectively moveable apart to not pinch the tube to enable the tube to be extruded round, whereby a round tube with an intermediate flattened oval shaped portion is produced.