Abstract: A compact welding wire feed device is provided capable of being mounted directly on a welding head carriage. The device comprises a ball bearing having an inside race with tangential entrance and exit guides to the race adjacent to opposite axial ends of the bearing. A hub member has an outside diameter less than the inside diameter of the race so that the hub member can be coaxially received in the race and a welding wire passed through the entrance guide and wrapped around the hub and out the exit guide. By now side-loading or expanding the hub against the inside of the race and driving the hub rotationally, the welding wire is continuously fed out the exit guide. The coaxial relationship of the hub and race provides for a very compact structure thereby permitting mounting of the wire feed directly on a welding head carriage adjacent to a weld head or even permitting the feed wire itself to be used as an electrode in a MIG welding system.

Abstract: An electric arc welding system includes programming circuits for controlling the position of a welding torch on a carriage wherein the carriage is caused to move along in the direction of a weld path on a member to be welded. The programming circuits cause the torch to move back and forth across the weld path as the carriage moves parallel to the weld path, the excursion time of the torch and dwell time of the torch on either side of the path at the limits of its excursion constituting the selected position program. The torch thus follows a repetitive generally truncated sawtooth pattern. The welding current to the torch is connected into the programming circuits to be responsive to a selected program so that the level of current provided during the dwell times is different from the level of current provided during the excursion times.