| 摘要 |
PURPOSE:To achieve solid elements, by drilling through-holes orthogonal to boom axial line with a suitable interval and fixing the elements inserted to the holes. CONSTITUTION:A number of through-holes 6 are drilled to a boom 5 orthogonally to the boom axial line with a suitable interval toward the boom axial line, a hollow cylinder element 7 is inserted to the hole 6, and the center is held to the boom 5. Next, an auxiliary pipe 8 made of plastic deformed material such as aluminum and brass is inserted to a cylinder hole 7a of the element 7 and located at the boom axial line of the element. Further, a rod tool 14, the external diameter of the tip of which is smaller than the inner diameter of the auxiliary pipe 8, and which has a taper 13 the outer diameter of the base of which is larger than the inner diameter of the pipe 8, is inserted from both sides, the both ends of the pipe 8 are spread out externally and the lengthwise movement of the element 7 to the boom 5 is fixed. |
