| 摘要 |
<p>PROBLEM TO BE SOLVED: To facilitate centering between the pin insertion holes of a bracket and a boss when the bracket is assembled to a boss through a coupling pin. SOLUTION: Circular annular grooves 14 and 15 formed in a V-shape in cross section in a manner to be formed in a concentric circular shape to a pin insertion hole 12A are formed in each of the end faces 11A of an arm boss 11. Further, a moving plate 18 is movably contained in the containing recessed part 16C of a bracket 16, and moving plate 18 is positioned axially of a coupling pin 22 by a positioning bolt 21. Further, elastic engaging bodies 19 and 20 are mounted in the mounting hole 18B of the moving plate 18 and the mounting hole 17B, respectively, of a bracket 17. Each elastic engaging body 19 is moved to each end face 11A of the arm boss 11 through each positioning bolt 21. The ball bodies 19B and 20B of the elastic engaging bodies 19 and 20 are elastically engaged with the annular grooves 14 and 15 through springs 19C and 20C, respectively.</p> |
