摘要 |
In the screw of the present invention, a screw shaft and knob have a torque controller which rotates the screw shaft and the knob together until a rotating torque between the screw shaft and the knob reaches a predetermined level, and slips the knob toward the screw shaft if the rotating torque exceeds the predetermined level, while the knob is rotated along a direction for screwing the screw; and the torque controller also rotates the screw shaft and the knob together even if the rotating torque exceeds the predetermined level, while the knob is rotated along a direction for unscrewing the screw. Therefore, the screw can properly fasten and unfasten with the screw controller.
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