| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a lock ring which has a strength not being deformed by a strength of fastening force against a male screw and can be removed from the male screw and reused even after the lock ring is used by being fastened to the male screw.SOLUTION: This lock ring R comprises a friction ring 30 formed with an annular concave part 33 at one end surface 30a while being concentric with a screw hole 31 of a bolt; and a plate ring 35 having, at a part of an inner circumferential edge of a central hole 36, a spring engaging part 35a which is fixed to the annular concave part and of which inner diameter is smaller than an outer diameter of a ridge of the bolt. The friction ring is formed by a requisite minimum thickness annular steel member in which a screw driver tool can be engaged with an outer circumference part 30c and operated to turn, and the other end surface 30b is provided with convexoconcave pitch surface 40. When it is rotated in such a direction as one it is loosened in respect to the bolt, the inner circumferential edge of the plate ring at one end surface is got into a thread groove of the bolt to forcedly press against the ridge of the bolt and at the same time also the other end surface shows that the pitch surface is abutted against a fastening end surface 20a of a nut 20 to generate synergistic large friction torque.</p> |
