| 摘要 |
PURPOSE:To cause the large driving horse power in manufacture to be unnecessary, while the tube to be produced is not rotated at all by a method in which while a pair of two nip rolls fixed in a posture of a twisted angle defined by the width of a bandlike sheet and the diameter of the tube, are rotated on a circle of a prescribed radium around the axis of the tube to be formed as its center, it is formed into a spiral tube. CONSTITUTION:A pair of two nip rolls 3, 3 nipping the bandlike sheet 2 continuously fed from a bobbin 1 and fixed in a posture of the twisted angle defined by the width (b) of the bandlike sheet and the diameter (d) of a tube, are rotated on a circle of a prescribed radius (r) around the axis P' of the tube P to be formed as its center. While the bandlike sheet 2 is wound in order by the rotation of planetary motion to the axis P' of the tube P, it is formed into the tube P, but the bandlike sheet 2 is twisted by the rotation of the nip rolls 3, 3 from the position of the start of winding. Then, the twist is removed by the rotation in the untwisting direction (arrow x) of the bobbin 1. The tube P is transferred into the axial direction by a pushing device 4 with the rotation of the nip rolls 3, 3, and is continuously formed into the tube. |
