| 摘要 |
PROBLEM TO BE SOLVED: To develop a nut which is easily engaged to a bolt and cannot be easily disengaged once coupled to the bolt. ! SOLUTION: A coil spring accommodation part is formed which has an inclined part where a distal end successively becomes a small diameter dimension at a rear diameter side of a nut. A distal end portion is tapered and a coil spring is incorporated of which the inner diameter is relatively tightly threaded to a bolt. The coil spring is mounted to an inner diameter tapered part of a nut body in a pressed state with a space at the rear diameter side. In fastening rotations of the nut to the bolt, continuously to a female screw of the nut, a spring part is also threaded in and engaged. In unfastening rotations of the nut, the coil spring part is fixed to the bolt in a groove part of the bolt by friction force and shrinkage force and meshed into the inclined part (tapered part) of the nut as a wedge, thereby preventing the nut from being unfastened. Engaging of the bolt and the nut |
