Abstract: The filler wire in hot wire-gas tungsten arc welding (HW-GTAW) apparatus is heated to near the melting point by application of the hot wire current over a determined length sufficient that the current required is low enough to avoid significant arc blow. This predetermined length of filler wire which approaches the molten state is supported by a ceramic sleeve which in turn may be protected by a stainless steel sheath.

Abstract: Narrow groove welding is accomplished with a welding apparatus containing an improved gas lens made of a sintered bronze material. The sintered bronze material requires the use of a higher gas supply pressure than is commonly used, but it results in a higher volume of laminar gas flow, thereby facilitating deep narrow groove welds. The sintered gas lens does not require the use of a skirt below the lens to maintain a column of laminar gas flow, thereby making it possible to mount a light source below the lens directly within the flow of cover gas and away from the line of view of the operator.

Abstract: Narrow groove welding is practiced using conventional welding apparatus including a torch block supporting an electrode and a primary, circular gas cup which directs a first flow of cover gas along the electrode, in combination with a rectangular, secondary gas cup detachably mounted coaxially with the primary gas cup and which directs a second, greater flow of cover gas around the flow of cover gas from the primary gas cup. The broad envelope of laminar flow cover gas thus produced is effective for making deep narrow groove welds and is stable enough for completing the weld cap.

Abstract: Both a system and a method for converting two AGTAW welders into a AGMAW welder is provided. The system generally comprises a MIG weldhead for replacing the TIG weldhead of one of the AGTAW welders, a pulser multiplier circuit for increasing the frequency of the power supply output current from 10 to between 300 and 800 pulses per second, and a wire feed motor and motor control circuit capable of feeding weld wire at a rate compatible with a AGMAW welding operation. In the method of the invention, the control circuit assembly of one of the AGTAW welders is connected in parallel to the power supplies of both of the two AGTAW welders, and the outputs of these power supplies are likewise connected in parallel. The TIG weldhead of one of the AGTAW welders is replaced with the MIG weldhead, and the pulser multiplier circuit is selectively connected to the current pulser of the single control circuit assembly which controls both power supplies.

Abstract: Arc welding apparatus and method for precisely welding abutting pipe end portions defining an interface having a seam or joint to welded. The apparatus includes a roller assembly for precisely rolling the apparatus around a track circumscribing one of the pipe portions so that the seam may be suitably welded. Connected to the roller assembly is a carriage which carries an electrode housing having an electrode housed therein. A gear rack is provided on the roller assembly for engaging a pinion gear on the carriage for precisely biasing the carriage and thus the electrode housing parallel to the longitudinal center axis of the pipe portions. Connected to the carriage is a lead screw assembly for precisely biasing the electrode housing and thus the electrode perpendicularly to the longitudinal center axis of the pipe portions to be welded. Connected to the electrode housing is a manipulator arm for precisely manipulating filler wire at the weld site.

Abstract: The invention is both a system and method for video monitoring a metal working process which involves the generation of an intense point source of light near or on a workpiece, such as an electric arc welding process. The system comprises a lens assembly for projecting an image of the point source of light and the area of the workpiece being worked onto the image sensing circuit of a television camera, a filter assembly having at least one filter element that includes both a central region of low light transmission for dimming the image of the point source of light projected onto the image sensing circuit, and a peripheral region of high light transmission for freely transmitting the image of the background surrounding the point source, and a mechanism for adjusting the apparent size of the central region of low light transmission relative to the image.