| 摘要 |
PURPOSE:To cause a part, where edge parts of two tapes are overlapped with each other to appear at each crest or trough of a spiral projection line, by a method wherein a pulality of tapes are simultaneously fed and wound in a manner that they are partiarlly overlapped on a peripheral surface of a rotary shaft body through shifting of the positions of the two tapes from each other by one complete pitch of the spiral projection line. CONSTITUTION:If two tapes 2 and 3 having the same width as each other are fed along a trough such that front edges 2a and 3a are displaced in a position by a full pitch, the front edges 2a and 3a alternately appear at a trough part in an outer peripheral surface of a tube. Simultaneously, rear edges 2b and 3b of the tapes 2 and 3, respectively, alternately appear at the crest part on the inner peripheral surface of the tube, the rear edge 2b of the first tape 2 and the front edge 2a of the first tape of the second turning coincide with each other at the inside and the outside of the pipe, and the rear edge 3b of the second tape 3 and the front edge 3b of the tape 3 of the second turning coincide with each other in a similar manner, and this causes said coincidence to alternately occur at each projection line. |
