A bolt includes a shank having a first end, a second end, a first external thread proximate to the first end, and a second external thread proximate to the second end. The first external thread twists in a first direction, the second external thread twists in a second direction, and the first direction is different from the second direction. The first external thread includes a minor diameter, the second external thread includes a major diameter, and the minor diameter of the first external thread is greater than the major diameter of the second external thread.

A bolt includes a shank having a first end, a second end, a first external thread proximate to the first end, and a second external thread proximate to the second end. The first external thread twists in a first direction, the second external thread twists in a second direction, and the first direction is different from the second direction. The first external thread includes a minor diameter, the second external thread includes a major diameter, and the minor diameter of the first external thread is greater than the major diameter of the second external thread.

A nonloosening bolt may comprise a first bolt and a second bolt. The first bolt may have a bolt head, and the second bolt may have a threaded tip. Conversely, the first bolt may have a threaded tip, and the second bolt may have a bolt head. The first bolt may comprise an eccentric columnar portion having a small-diameter male-threaded portion at an outside circumference thereof. The second bolt may comprise a small-diameter female-threaded hole that threadedly engages with the small-diameter threaded portion. Threaded engagement between the small-diameter threaded portion and the small-diameter threaded hole may result in a constitution in which the central axes and pitches of the threaded portions at the outside circumferences of the first bolt and the second bolt are aligned. An eccentric frustoconical protrusion may be provided at the first bolt so as to fit within an eccentric frustoconical hole provided at the second bolt.

A nonloosening bolt may comprise a first bolt and a second bolt. The first bolt may have a bolt head, and the second bolt may have a threaded tip. Conversely, the first bolt may have a threaded tip, and the second bolt may have a bolt head. The first bolt may comprise an eccentric columnar portion having a small-diameter male-threaded portion at an outside circumference thereof. The second bolt may comprise a small-diameter female-threaded hole that threadedly engages with the small-diameter threaded portion. Threaded engagement between the small-diameter threaded portion and the small-diameter threaded hole may result in a constitution in which the central axes and pitches of the threaded portions at the outside circumferences of the first bolt and the second bolt are aligned. An eccentric frustoconical protrusion may be provided at the first bolt so as to fit within an eccentric frustoconical hole provided at the second bolt.

A precision adjustment fastener mechanism comprises a base, a platform, and a locking push-pull fastener assembly. The base has a first aperture and the platform has a second aperture. The fastener assembly is disposed within the second aperture. The fastener assembly comprises a clamping fastener having a portion positioned in the first aperture, a sleeve having a third aperture extending along an axis of the sleeve. The clamping fastener is positioned within the third aperture. The sleeve comprises a first portion moveable relative to a second portion along the axis. The first portion and the second portion each comprise outer threads. An axial displacement portion separates the first and second portions and transmits a torque between the first and second portions. The axial displacement portion facilitates movement of the first and second portions to bind threads of the first and second portions with the threads of the platform.

A nut assembly is disclosed, including: a first nut provided with an accommodating cavity; a second nut provided with a collar portion at one end, where the collar portion is movably inserted in the accommodating cavity, and at least one notch is formed on a side wall of the collar portion; an squeezing structure, where when the first nut and the second nut move close to each other, the extrusion structure is capable of squeezing the collar portion to shrink and close; and an anti-dropping structure, where the anti-dropping structure is capable of restricting the collar portion from dropping out of the accommodating cavity.

A nut assembly is disclosed, including: a first nut provided with an accommodating cavity; a second nut provided with a collar portion at one end, where the collar portion is movably inserted in the accommodating cavity, and at least one notch is formed on a side wall of the collar portion; an squeezing structure, where when the first nut and the second nut move close to each other, the extrusion structure is capable of squeezing the collar portion to shrink and close; and an anti-dropping structure, where the anti-dropping structure is capable of restricting the collar portion from dropping out of the accommodating cavity.

The present invention relates to an anti-loosening bolt coupled to a bolt and a spring and, more specifically, to an anti-loosening bolt which can: prevent the bolt from being unintentionally loosened by a rotating object or by continuous long-time or momentary vibration; be fixed on a wall; be combined with a nut; prevent a periodic shaking phenomenon; and be reused.

The present invention relates to an anti-loosening bolt coupled to a bolt and a spring and, more specifically, to an anti-loosening bolt which can: prevent the bolt from being unintentionally loosened by a rotating object or by continuous long-time or momentary vibration; be fixed on a wall; be combined with a nut; prevent a periodic shaking phenomenon; and be reused.

A nonreversible anti-backlash nut comprises a first nut body and a second nut which are provided with internal threads, and a shrinkage ring which is capable of shrinking inwards in a radial direction and is disposed between the first nut body and the second nut body. Nut body chamfers are separately arranged on sides, connected with the shrinkage ring, of the first nut body and the second nut body. A shrinkage ring chamfer is arranged at a position, corresponding to the nut body chamfers, of the shrinkage ring. After the nut is assembled, the shrinkage ring provides a shrinkage force to push, via the chamfers, the first nut body and the second nut body away from each other, so that an axial clearance of the nut is eliminated. Compared with the prior art, the nut has a better and more uniform clearance elimination effect.