To provide a falling-off preventing mechanism providing a falling-off preventing function without a falling off preventing member and superior in assembly workability and capable of increasing movable range of a bolt.
A second member 20 is attached on a first member 30 with using a bolt 10. An intermediate part 16 between an external thread part 12 and a head of the bolt has a diameter 'd' smaller than an inner diameter Mi of the external thread part and at least a part of bolt head width is larger than an outer diameter Mo of the external thread. A internal thread 22 meshing with the external thread part of the bolt and a slot 24 leading to the internal thread are formed on the second member 20 and an internal thread 32 meshing with the external thread of the bolt 10 is formed on the first member 30. Width W of the slot is larger than a diameter 'd' of the intermediate part of the bolt and is smaller than an outer diameter of the internal thread 22.
KURIHARA SATOSHI
MORIBE MAKOTO
