Patent ID: 9618030
Date: 2017-04-11
CPC Classifications: F16B

Claim:
1. A lock nut having a lock nut body including an internally threaded upstream end portion of the lock nut body and a non-threaded downstream end portion of the lock nut body housing a spiral coil spring positioned within the non-threaded downstream end portion of the lock nut body and into which a bolt is operable to be engaged from an upstream end of the spiral coil spring to a downstream end of the spiral coil spring, wherein the spiral coil spring is inserted in the lock nut body, and on the downstream end of the spiral coil spring a downstream bent portion is formed which is bent radially outward, and the spiral coil spring is coiled so that a bolt is operable to be screwed into the internally threaded portion of the lock nut body and through the spiral spring portion of the lock nut body from an upstream end to a downstream end of the lock nut body and a bolt is further operable to be fastened with the spiral coil spring, and the lock nut body has a threaded part on an inner surface of the upstream end of the lock nut body to be operably engaged with a bolt, and the lock nut body has a non-threaded part on an inner surface of the downstream end of the lock nut body, the non-threaded part has an inner diameter larger than that of the threaded part and houses the spiral coil spring, and the non-threaded part includes an upstream radially inwardly extending step and a downstream radially inwardly extending step with a reduced diameter, and on a downstream surface of the lock nut body is formed a radially extending recess, into which the downstream bent portion of the spiral coil spring is inserted, so that, if an external force is applied at the spiral coil spring in a counterclockwise release direction of the nut, the downstream bent portion is retained within the recess, and the upstream end of the spiral coil spring is embraced within the non-threaded part and elastically contacts against the upstream step, and a stopper extending inward radially is formed on an inner surface of the non-threaded part, and the stopper is positioned to be separated from the upstream end of the spiral coil spring to resist releasing of bolt from engagement with the lock nut.