device and method for the influence of the cross-section of rolling way to bend pipes and other elongated objects

摘要

1383364 Bending tubes COJAFEX NV 6 March 1972 [5 March 1971] 10303/72 Heading B5A [Also in Divisions B3 and C1] The cross-section of a plastics tube or other elongated member is controlled during bending by heating a narrow transverse zone of the tube while applying a bending moment, the zone lying at least in part in plane which does not pass through the centre of curvature of the arc into which the member is to be bent. Fig. 4, shows a tube being bent by an arm (not shown), pivoting about axis 1, the heated zone being inclined to the plane 4 transverse to the tube and passing through axis 1, so that the heated zone is downstream of plane 4 on the inside of the bend at 2e, and upstream on the outside of the bend at 2d. The tube may be cooled downstream of the heater, which may be adjustable. It is stated that displacement of the tube wall during bending may be compensated for or even over-compensated. The heated zone may be parallel to plane 4, but upstream (Fig. 2), or downstream (Fig. 3), of it, or may be in part in plane 4 and in part inclined to it (Fig. 5). The position of the heater may be adjustable, and may be adjusted automatically in response to the sensed ovality of the tube. Heating may be effected by induction heating or other radiation, or convection.