Abstract: A mechanism for driving a robot hand mounted on a robot arm includes a pair of planetary gear assemblies coupled to motors for swinging the robot hand about a first shaft and for rotating the robot hand about a second shaft through transmission systems. During swinging motion of the robot hand about the first shaft, rotative power from the motor which causes such rotation is transmitted by the planetary gear assemblies to the second shaft also, so that rotation of the robot hand resulting from the swinging motion of the robot hand can be cancelled out.

Abstract: A control device for a balancer includes a load detector for determining the torque exerted on a driving screw attributable to the load driven and supported thereby. A fluid pressure control device increases or decreases the pressure input to a balancing torque generator in response to the detected load at a given time instant.