Lowe, Price, LeBlanc & Becker
Locking nut and a fastening structure made up of the locking nut and a member being tightened
 The invention is intended to provide a fastening structure made up of a nut and a to-be-tightened member which does not get loose even when used in places where it is subject to large vibrations. The nut has a cylindrical female screw extension portion which projects from the seat of the nut and which has a female screw formed in the inner circumferential surface thereof. The to-be-tightened member which is on the male screw side is formed with a fastening hole into which the female screw extension portion is to be fitted. The inner surface of the fastening hole and the outer surface of the female screw extension portion are tapered so that there is a taper angle difference. As the nut is fastened onto the male screw, the female screw extension portion is pushed inwardly and deformed due to the taper angle difference so that the female screw formed on the female screw extension portion is pressed against the male screw. When, with the nut fastened in this way, the fastening force applied to the nut is removed, the female screw remains deformed and pressed against the male screw, preventing the nut from becoming loose. 
Kabushiki Kaisha Suzuki Rashi Seisakusho
F F
F16B F16B
additional inventional
Yasuo
Suzuki