There is provided a resistance spot welding apparatus including a first rod-shaped electrode body, second rod-shaped electrode body, first ring-shaped member, second ring-shaped member, first elastic body, and second elastic body. The first rod-shaped electrode body and second rod-shaped electrode body are arranged facing each other, the first rod-shaped electrode body is inserted into a through hole of the first ring-shaped member, the first elastic body is connected to an opposite side of first ring-shaped member to second rod-shaped electrode body side, the first rod-shaped electrode body and first ring-shaped member are not electrically connected to each other, the second rod-shaped electrode body is inserted into a through hole of the second ring-shaped member, the second elastic body is connected to an opposite side of second ring-shaped member to first rod-shaped electrode body side, and the second rod-shaped electrode body and second ring-shaped member are not electrically connected each other.

A method is provided for transporting flat materials to be welded together, specifically a first flange and/or a second flange and a web for producing a beam through a welding station. The flat materials are aligned and guided by rollers. A slide is arranged upstream of the welding station in the run-through direction and a gripper is arranged downstream of the welding station. The slide introduces the flat materials into the welding station and moves them as far as a first position by means of a pushing movement at an advancement speed. The gripper grips the flat materials at the first position, and pulls the flat materials out of the welding station at the pulling speed and moves them as far as a second position by means of a pulling movement. The slide is arranged upstream of the welding station and the gripper is arranged downstream of the welding station.

The present invention provides improved systems for supporting and translating a robotic welder around a structural column to perform automatic welding of joints. The improved system permits a robotic welder to perform the required welds in at least half the time it would take a human welder, thereby significantly reducing construction costs, improving safety of construction, and improving accuracy of welding, and requiring less testing of the welds.