| 摘要 |
PROBLEM TO BE SOLVED: To manufacture a pipe of high circularity without any crack while having an anti-skid rugged pattern being regularly formed on its surface. SOLUTION: A metallic strip having an rugged pattern on its surface is bent in a tubular shape, and both ends joining parts are welded to each other to manufacture an anti-skid pipe. In this condition, rugged parts formed on the surface of the metallic strip are arranged in a staggered manner so that projecting parts adjacent to each other in the width direction of the metallic strip are positioned in an area held by two projecting parts adjacent to each other in the longitudinal direction. The rugged parts are formed only in a center part except both side ends of the metallic strip. COPYRIGHT: (C)2009,JPO&INPIT |
