Abstract: A welding robot is provided with a first joint member in addition to a welding gun. A work holder provided with a second joint member adapted to be connected with the first joint member and a clamp mechanism for gripping a workpiece is positioned in a predetermined waiting position. The welding robot accomplishes welding on a workpiece transferred to a first station and when the welding is completed, the welding robot approaches the work holder in the waiting position to connect the first and second joint members with each other. Then the robot returns to the first station carrying the work holder and permits the clamp mechanism of the work holder to grip the workpiece at the first station. Thereafter, the robot moves to a second station to transfer the workpiece from the first station to the second station. Then, the clamp mechanism releases the workpiece and the robot moves away from the second station to the waiting position with the workpiece left at the second station.

Abstract: A plurality of pivoted robots each having both a welding gun and a transferring member for transferring a part are arranged so that the swinging locus of each pivoted robot intersects with that of at least one of the other robots. A working station is provided at the intersection of the swinging loci and the pivoted robots accomplish welding on the corresponding part at the working station and transfer it to the next station.