Arm structure for man type working robots

An arm structure for an anthropomorphic robot, comprising a shoulder joint assembly having a first joint coupled to a torso for rotation about a first axis, a second joint coupled to the first joint for rotation about a second axis crossing the first axis, and a third joint coupled to the second joint for rotation about a third axis crossing the second axis, the first through third axes intersecting at a single point, and an elbow joint assembly coupled to the third joint of the shoulder joint assembly, characterized in that

• the position and posture of the first through third joints of said shoulder joint assembly and the position of said elbow joint assembly with respect to the third joint are established such that said elbow joint assembly is located above a horizontal plane lying through the point of intersection of the axes of said first through third joints, while said shoulder joint assembly is operated into a singularity state wherein the first axis of said first joint and the third axis of said third joint are aligned with each other and said elbow joint assembly is positioned laterally of said torso.