| 摘要 |
975,697. Making tubes. CALUMET & HECLA Inc. April 22, 1963 [June 11, 1962], No. 15866/63. Heading F2P. Tubing is made by forming edge portions of strip into narrow flanges extending generally perpendicular to the strip and in the same direction, tapering the flanges outwardly to bias the strip toward a helical configuration, coiling the strip into a tight helix with the outer surfaces of the flanges in abutment and bonding those surfaces together. The flanges are turned up between pairs of rollers 24, 28 and 22, 27 and then tapered between an anvil 38 and rollers 35, 36 on opposite sides of the mandrel. The rollers are driven to assist the feeding of the strip to a mandrel 12, the rotation of which also draws the strip on to it. The position of the rollers 35, 36 in alignment with the axis of the mandrel and not with the width of the strip, normal to its edges, tends to form the strip into a helix. The roller 35 also engages the inner face of the first convolution of the flange 32 to press the outside faces of adjacent flanges together, Fig. 4. In a modification, the rollers are positioned where they only taper the flanges against the anvil, i.e. as shown dotted at 35a, 36a. The contiguous flanges are welded together between elements 40, 42, which, for metal strip, e.g. aluminium or an alloy thereof, are electrodes and for plastic strip are electrically heated jaws. The flanges may subsequently be flattened by a roller 50. |
