Patent ID: 7674063

Claim:
A rotatable joint, comprising: a socket; a rotatable arm with a pivot hole defined therein; a supporting shaft including a first shaft portion and a second shaft portion, a threaded hole defined in the first shaft portion, the first shaft portion extending through the pivot hole, and the second shaft portion fixed to the socket; a fastening member including a threaded portion for engaging in the threaded hole of the supporting shaft; an adjusting member disposed at the threaded portion of the fastening member; and a resilient module disposed between the rotatable arm and the adjusting member for providing an axial resilient force, and the axial resilient force being fine tuned by moving the adjusting member along the threaded portion of the fastening member; wherein the socket is substantially a hollow spheroid comprising a first half and a second half attached to the first half, and a shaft receptacle extends from an inner surface of the first half for supporting the second shaft portion of the supporting shaft; the rotatable arm comprises a ball joint and an arm extension opposite to the ball joint, two frictional grooves are defined in two opposite sides of the ball joint, the pivot hole is defined through a center of the ball joint communicating between the two frictional grooves, and part of the resilient module is received in one of the frictional grooves, the supporting shaft further comprises a flange portion disposed between the first shaft portion and the second shaft portion, and the flange portion of the supporting shaft engages in the other one of the frictional grooves.