| 摘要 |
An object of the present invention is to provide a duplex threaded body having a right-handed thread and a left-handed thread on the circumferential surface of a single solid member. In addition, an object of the present invention is to provide a single-nut or double-nut type internally-threaded body that demonstrates a locking effect even at an intermediate position without substantially loosening by using a combination of a duplex externally-threaded body and one or more internally-threaded bodies. Moreover, an object of the present invention is to provide a screw structure in which a pair of internally-threaded bodies can only be removed by destruction once they are mutually coupled when screwed onto a duplex externally-threaded body, thereby making it possible to impart tamper-proof characteristics in addition to a locking effect. The duplex externally-threaded body of the present invention has, on the outer circumferential surface of a rod-like member, an overlapping region in which a clockwise spiral right-handed thread and a counter-clockwise spiral left-handed thread are provided in at least an overlapping manner. Moreover, the present invention makes it possible to use, alone or in combination, a right-handed internally-threaded body in which a right-handed thread is formed, and a left-handed internally-threaded body in which a left-handed thread is formed, that are screwed onto a duplex externally-threaded body. |
