| 摘要 |
An upper member (13) is superposed, through a bolt hole (14), onto the top of a lower member (15) in which a bolt (1) is implanted, a truncated cone section (5) is provided at the upper portion of a fastening nut (3) screwed onto the upper member, vertical division grooves (7) are provided in the radial direction in 4-6 locations in the truncated cone section, and trapezoidal thin plates (8) are somewhat firmly press-fitted into all of the vertical division grooves. The fastening nut is firmly screwed onto the bolt, after which a locking nut (11) is screwed on from above, thereby pressing in the trapezoidal thin plates (8) fitted into the vertical division grooves by means of truncated-cone-shaped holes (12) in the lower portion of the locking nut, and causing the trapezoidal thin plates to bite into the crests of the male thread (2) of the bolt, thus preventing the fastening nut from rotating with respect to the bolt. |
