A robot arm with upper (33) and lower (37) arm sections has shoulder, elbow and wrist joints. The shoulder joint is triaxial having a sweep axis (53), a swivel axis (55) and a yaw axis (51), the three axes intersecting at a point, (and shown mutually perpendicular). The elbow joint has a single extension axis (57) parallel to the swivel axis (55) of the shoulder joint. The wrist joint has a pitch axis (59) parallel to the elbow extension axis (57). Wrist yaw motion is provided by yaw motion of the shoulder joint about the yaw axis (51) of the shoulder joint so that the robot wrist may have low mass. <IMAGE>
ROBOT ARM WITH SPLIT WRIST MOTION