A self-locking screw wherein the self-locking function is maintained during many cutter head building and truing cycles. The inventive screw includes a self-locking feature having high elasticity and high self-locking torque. The screw includes a slot filled with an elastic compliant material.

A fastener assembly having a nut with interior threads extending from a first end to an intermediate end wall, a narrowed diameter aperture extending from the end wall toward a second end. A first screw has a shaft exhibiting a first exterior thread pattern rotationally inter-engaging with the interior threads of the nut when installed through the first end. A recess formed in an end of the shaft exhibiting a further plurality of interior threads matching a direction of the first thread pattern. A second screw has a second exterior thread pattern opposite the first pattern and, upon being installed through the narrowed aperture, rotationally inter-engaging the interior threads of the first screw, with loosening of either screw being prevented by their counter-threaded orientation. A head of the second screw exhibiting an outer annular rim establishing a resistance fit within an entranceway location of the nut.

A fastener assembly having a nut with interior threads extending from a first end to an intermediate end wall, a narrowed diameter aperture extending from the end wall toward a second end. A first screw has a shaft exhibiting a first exterior thread pattern rotationally inter-engaging with the interior threads of the nut when installed through the first end. A recess formed in an end of the shaft exhibiting a further plurality of interior threads matching a direction of the first thread pattern. A second screw has a second exterior thread pattern opposite the first pattern and, upon being installed through the narrowed aperture, rotationally inter-engaging the interior threads of the first screw, with loosening of either screw being prevented by their counter-threaded orientation. A head of the second screw exhibiting an outer annular rim establishing a resistance fit within an entranceway location of the nut.

A coupler including a fitting for mounting to externally threaded reinforcing bar for use in concrete construction, the fitting including a body having a portion with an internal thread for engagement with the thread of the reinforcing bar, wherein the internal thread has an asymmetric thread form having an outer ramped portion and an inner ramped portion, the outer ramped portion being inclined to a central axis of the coupler at a first angle, the inner ramped portion being inclined to the central axis of the coupler at a second angle, the first angle being smaller in magnitude than the second angle.

A locking nut system includes a threaded member with a first threaded area having a first thread direction and a second threaded area having a second thread direction opposite the first thread direction in which a plurality of crests extend across the first and second threaded areas with a constant pitch between the crests such that minimal material is removed, structural integrity is maintained, and a first nut secures the threaded member to a workpiece and a second opposing nut renders the first nut stationary.

A locking nut system includes a threaded member with a first threaded area having a first thread direction and a second threaded area having a second thread direction opposite the first thread direction in which a plurality of crests extend across the first and second threaded areas with a constant pitch between the crests such that minimal material is removed, structural integrity is maintained, and a first nut secures the threaded member to a workpiece and a second opposing nut renders the first nut stationary.

The invention concerns a unit (210) for a locking device, comprising: a nut (212) comprising two coaxial taps in opposite directions; and a ring (213); said ring including a third tap (38); the first (18) and third (38) taps being capable of engaging with a single first thread (22); said ring including a second thread (40) capable of engaging with the second tap (20) of the nut. The unit further comprises a washer (214) configured (274) so as to be inserted around one (212) of the nut and the ring, the washer comprising an elastic engagement means (272) for engaging with the other (213) of the ring and the nut in an installation position of the unit, so as to prevent the ring and the nut from rotating relative to each other.

The invention concerns a unit (210) for a locking device, comprising: a nut (212) comprising two coaxial taps in opposite directions; and a ring (213); said ring including a third tap (38); the first (18) and third (38) taps being capable of engaging with a single first thread (22); said ring including a second thread (40) capable of engaging with the second tap (20) of the nut. The unit further comprises a washer (214) configured (274) so as to be inserted around one (212) of the nut and the ring, the washer comprising an elastic engagement means (272) for engaging with the other (213) of the ring and the nut in an installation position of the unit, so as to prevent the ring and the nut from rotating relative to each other.

Fastening art with double nuts for a dual-threaded screw structure is provided, in which loosening is not created even if the structure is subjected to vibration. A spring washer is caused to intervene between the nuts, when double nuts of an inner nut and an outer nut are screwed onto a thread portion on which dual-threaded screw is formed. Only by tightening the outer nut, also the inner nut is tightened and the spring washer is compressed. Both axial force for clamping the fastened member and axial force between the nuts can be secured with the spring washer, so that loosening does not occur easily.

Fastening art with double nuts for a dual-threaded screw structure is provided, in which loosening is not created even if the structure is subjected to vibration. A spring washer is caused to intervene between the nuts, when double nuts of an inner nut and an outer nut are screwed onto a thread portion on which dual-threaded screw is formed. Only by tightening the outer nut, also the inner nut is tightened and the spring washer is compressed. Both axial force for clamping the fastened member and axial force between the nuts can be secured with the spring washer, so that loosening does not occur easily.