| 摘要 |
<p>PURPOSE:To obtain the titled long article, which assures the entwining of a liana around it, and to enable firmly binding a string or the like to the long article which may have even a small number of projections, by helically forming projections provided with concavities in fixed intervals along the axial direction of the long article. CONSTITUTION:Projections 4-7 are formed helically along the longitudinal direction in the same intervals on the surface of a synthetic resin coating layer 3 formed on the periphery of a long body 2 made of a thin steel pipe. These projections 4-7 are provided with concavities 8, 9,..., 10, 11,... formed by smashing each projection in nearly the same intervals under the condition that the synthetic resin coating layer is still in a soft state and then curing the smashed parts. The position of the concavities and that of the projections 14, 15, 16,... are controlled in a manner such that they do not fall in line together along the circumferential direction of the long body.</p> |
