| 摘要 |
The present invention provides a tubular member 10 and method of forming the same in which the tubular member 10 comprises one or more strips of self overlapping helically wound material 12 having corrugations with radially adjacent curves sharing the same origin of bend radius O formed therein and including a step portion or depression 22 which allows the edges 14, 16 of each strip to lie within the profile of the combined strips. The structure is manufactured by helically winding said strip 12 in self overlapping manner such as to cause the edges 14, 16 to sit within the depression 22 whilst providing a multi-layer structure. |
