US Patent 7765890 Industrial robot

An industrial robot has an arm, a wrist element rotatably interconnected to the arm, a work tool mounted on a distal end of the wrist element, and a motor mounted on the wrist element. An umbilical-member connected to the work tool and a flat cable connected to the motor are disposed to run along the wrist element from the arm side to the work tool or to the motor. A pipe member extending in a direction of a rotation axis of the wrist element is provided inside the arm and the umbilical-member connected to the work tool is passed inside the pipe member. The flat cable connected to the motor is wound around outside of the pipe member, with the flat cable arranged to become slack in a rotating direction of the wrist element.