| 摘要 |
<p>METHOD AND APPARATUS FOR MAKING MULTI-LAYER SPIRAL PIPE An apparatus and method for continuously forming multi-layer metal pipe from at least two elongated sheets of metal, One sheet is impressed with longitudinal corrugations in a rolling device and the second sheet, being uncorrugated, is then positioned contiguously upon the first, forming a multi-layer sheet. One or more removable modules is mounted in the rolling device to accurately align and guide the second sheet into position upon the first. Complementary portions of a single corrugation are then formed in the marginal edges of the multi-layer sheet and the sheet is spiralled into adjacent, helical convolutions in a pipe forming device, with the uncorrugated sheet forming the pipe interior. The adjacent convolutions are joined in a helical seam in the single corrugation by a seaming device located in the pipe forming device. In the primary embodiment of the invention, the seam is formed as a double lock seam along a neutral axis of the single corrugation.</p> |
