Patent ID: 7975568

Claim:
A robotic arm assembly comprising: a hollow columnar shaft; a driving mechanism including a rotor and a stator, the rotor being rotatable relative to the stator, and the rotor defining an interior coaxial space in which to coaxially receive the hollow columnar shaft, so that the rotor is coaxially rotatable around the columnar shaft; a first arm having proximal and distal pivotal ends rigidly mounted on the rotor such that the first arm is drivable to rotate by the driving mechanism; a second arm having proximal and distal pivotal ends, the proximal pivotal end of the second arm being pivotally connected to the proximal pivotal end of the first arm; a first timing pulley mounted coaxially onto the columnar shaft; a second timing pulley spaced from the first timing pulley which is drivable to rotate together with rotation of the first arm; and a timing belt connecting the first and second timing pulleys that is operative to rotate the second arm relative to the first arm as the first arm is driven to rotate by the driving mechanism, such that the distal pivotal ends of the first and second arms are configured to always lie along a substantially straight line.