Abstract: The valve body of a gas torch is provided with a combined preheat oxygen and cutting oxygen valve unit in which the respective valves are coaxially interengaged and mounted in a single bore provided therefor in the valve body. The preheat oxygen valve is rotatable relative to the bore to control the flow of preheat oxygen to the torch tip, and the cutting oxygen valve is axially displaceable relative to the preheat oxygen valve to control the flow of cutting oxygen to the torch tip. The preheat oxygen valve includes an operating knob by which the valve is rotated and which knob is disposed beneath a pivotal operating lever by which the cutting oxygen valve is operated.

Abstract: A combination control valve and check valve for a gas torch is disclosed wherein a check valve is positioned within an annular control valve member downstream of a spherical control valve element with which the annular control valve member cooperates to open and close the control valve and thus the flow of gas from a source to a gas torch. The check valve protects the control valve under reverse gas flow conditions.

Abstract: A method of and welder for welding a corrosion resistant, wallpaper alloy to the inside surface of a vessel wall formed from a corrosion susceptible steel sheet after the wallpaper alloy has been affixed to the inside to provide an exposed seam of wallpaper alloy extending in a given path wherein the method and welder comprising moving a welding wire toward the seam, melting and depositing the welding wire onto the seam along the path by a short circuit arc welding process of the type having a welding cycle with a short condition and an arcing condition, which arcing condition constitutes a plasma boost portion with a set peak current level followed by a plasma portion with a current decreasing from said peak current level toward a set background current level with a given time between the plasma boost portion and the short condition andsetting the length of time of the plasma portion of the arcing condition to a value greater than 25% of the given time or greater than 2.0 ms.

Abstract: A platform for use in loading and supporting a gas cylinder onto a movable welder undercarriage which platform comprises a lower cylinder support pate with a rear end, a front end and a normal level cylinder supporting position; means for mounting the platform on the rear of the undercarriage to pivot about a transverse axis in a first pivot direction to a cylinder loading position with the rear end of the support plate tilted downward against the floor and in a second pivot direction with the support plate in the cylinder support position, where the weight of said cylinder is one the side of the pivot axis toward the front end of the support plate; and, stop means for preventing rotation of the platform abut the pivot axis in the second direction beyond the normal position of the support plate of the platform.

Abstract: A plasma torch comprising an elongated electrically conductive nozzle with an internal, generally cylindrical chamber; an electrically conductive electrode with an elongated, cylindrical nose extending into the cylindrical chamber of the nozzle to define a relatively thin, elongated annular gas passage between the nozzle and the electrode nose, wherein the electrode includes a cylindrical portion above the nose, which portion has axially extending swirl grooves; and, a separate insulator sleeve engaging both the cylindrical portion and the nozzle for holding the electrode nose concentric with said cylindrical chamber of the nozzle. The nozzle includes means for venting a portion of said cooling gas from the relatively thin annular gas passage.

Abstract: In an inverter power supply with an output transformer including a core of magnetically permeable material with an effective area, a primary winding on the core and a secondary output winding on the core; a pulse width modulator with a first output polarity and a second output polarity for alternately creating a first gate signal during the first output polarity and a second gate signal during the second output polarity; and, means for controlling the duration of said first and second gate signals to control the alternating output current at the secondary output winding, the improvement comprising: operating the core in quadrants I and III of the B-H graph by controlling its effective area of the core and including sensing means for creating a control signal indicative of impending saturation of the core during either one of the first and second gate signals and protection means for terminating the one gate signal in response to the control signal, while allowing the pulse width modulator to create next outpu

Abstract: A cover for a reel of welding wire comprises a sleeve having axially opposite ends extending across the outer peripheries of the flanges of the reel and having radially inwardly open circumferentially extending recesses interengaging with the flanges to releasably axially retain the sleeve on the reel and to seal the space between the flanges so as to protect welding wire wound about the hub of the reel between the flanges from exposure to air and moisture. Seals are provided between the recesses and reel flanges for the latter purpose. In accordance with another embodiment, the cover comprises two portions which snap-lock together to completely enclose the reel. The reel and cover are relatively rotatable and in accordance with another aspect of the invention the cover can remain on the reel during use and is provided with an integral or detachable nose which supports the wire during unwinding thereof from the reel.

Abstract: A fuel gas and preheat oxygen mixer for a gas torch comprises a bore in the torch head receiving a gas mixing insert having an axially thin peripheral gas mixing recess which receives preheat oxygen and fuel gas from corresponding manifold areas across radially thin metering passages. The gases are mixed in the mixing recess and delivered to the torch tip through delivery passages which, together with the mixing recess and metering passages provide gas flow paths having abrupt directional changes, all of which cooperatively resist flashbacks during use of the torch.

Abstract: A power supply for supplying a substantially square wave of current to a welding arc and including a source of A.C. power having a succession of positive and negative portions forming an input voltage cycle; first switch means for initiating a positive output current pulse at a selected first switching point during the positive portion of the input voltage cycle; second switch means for initiating a negative output current pulse at a selected second switching point during the negative portion of the input voltage cycle; means for sensing the output current through the arc; means responsive to the output current for creating a command signal as a voltage level which varies according to the desired instantaneous output current through the arc; and, control means for automatically selecting the first and second switching points in response to the voltage level.

Abstract: A method and system of controlling the output current/voltage characteristic curve of an engine driven alternator welder with a maximum open circuit output voltage, including a rotary engine, a three phase alternator, a rectifier bridge having a number of electronic switching devices for directing current to the output at an operating point determined by the firing angle of the switching devices, a sensor for sensing output current, a sensor for sensing output voltage, and a microprocessor output control device for controlling the firing angles of said switching devices in response to the sensed current and sensed voltage.

Abstract: A portable vacuum for fume and dust extraction includes a main housing shell, at least one fan within the shell for creating suction and a motor for driving the fan. A separate filter container is located within the main housing shell and a filter is located within the filter container for extracting fume and dust. Within the inner filter perimeter is located a generally H-shaped self propelled cleaning device having air outlets for cleaning the filter with compressed air and for rotating the cleaning device relative to the filter.

Abstract: A cover for a reel of welding wire comprises a sleeve having axially opposite ends extending across the outer peripheries of the flanges of the reel and having radially inwardly open circumferentially extending recesses interengaging with the flanges to releasably axially retain the sleeve on the reel and to seal the space between the flanges so as to protect welding wire wound about the hub of the reel between the flanges from exposure to air and moisture. Seals are provided between the recesses and reel flanges for the latter purpose. In accordance with another embodiment, the cover comprises two portions which snap-lock together to completely enclose the reel. The reel and cover are relatively rotatable and in accordance with another aspect of the invention the cover can remain on the reel during use and is provided with an integral or detachable nose which supports the wire during unwinding thereof from the reel.

Abstract: A fuel gas and oxygen mixer for a gas torch comprises a tubular body having a mixing passage extending therethrough and having an upstream end connected to sources of a fuel gas and oxygen and a downstream end for delivering a mixture of the fuel gas and oxygen to a torch tip. The fuel gas is axially supplied to the upstream end of the mixer, and the oxygen flows along the outer surface of the body in the upstream direction from a point adjacent the downstream end of the body and then into the mixing passage through radial ports adjacent to the upstream end of the body. The counter flow of oxygen is through a passageway which provides for cooling of the mixer during normal operation of the torch and for the quenching of reversely flowing hot gases during a back fire.

Abstract: An engine-driven, multiple-phase, alternator-powered SCR rectified arc welding power supply using a single synchronizing winding within the alternator providing signals to a synchronizing digitizer which masks noise for most of each cycle of the alternator. The synchronizing circuitry prevents spurious synchronizing signals.

Abstract: A welding power supply having a multiphase alternator and a thyristor rectifier using a control circuit to selectively prevent firing of thyristors when a short circuit occurs. Reliable operation of an alternator welding power supply under short circuit conditions is achieved.

Abstract: A valve for controlling the flow of a gas in a gas burning torch comprises a housing having a flow passageway therethrough, a valve seat in the passageway, and a valve stem carrying a ball valve element for engaging and disengaging the valve seat to respectively close and open said passageway. A rotatable operating knob for displacing the valve stem is isolated therefrom by a ball thrust bearing, and the valve stem is supported in the housing for rocking movement transverse to the stem axis.

Abstract: A flux cored arc welding electrode of the type used with external shielding gas wherein the electrode comprises an outer ferrous sheath and a particulate fill material comprising an acidic flux system and alloying agents with the fill material including an arc stabilizer, titanium dioxide, calcium fluoride, an alloying system of 0-4.0 percent by weight of electrode selected from the class consisting of aluminum, silicon, titanium, carbon and manganese. Iron powder controls the percentage of the fill of the electrode and 0.2-1.0 percent by weight of electrode is polytetrafluoroethylene powder.

Abstract: A system for locating a voltage sensitive parameter of an electric arc welding wire, which parameter is indicative of the welder perceived welding characteristics of said wire, said system comprises: means for feeding said wire toward a workpiece; means for applying a voltage between said wire and said workpiece whereby a welding arc is created between said wire and said workpiece to melt and deposit said wire onto said workpiece by a voltage sensitive arc welding procedure; means for gradually changing said applied voltage whereby said welding procedure shifts through a transfer region and between spray and globular welding; means detecting the actual voltage between the wire and workpiece as said applied voltage is changed; means for sensing each time when said actual voltage decreases below a selected threshold voltage; means for averaging the sensed number of times; means for detecting the applied voltage value when the averaged sensed number of times equals a selected number; and, means for selecting sai

Abstract: A cored electrode for gas shielded arc welding to deposit a weld metal bead, where the electrode has a core of fill material surrounded by a ferrous tube with the fill material having alloying agents and oxide fluxing ingredients including, by weight of fill material, 40-60% titanium dioxide, 0.3-0.5% boron oxide, and 1.0-5.0% aluminum powder, with the aluminum powder having a higher affinity for oxygen than the oxide fluxing ingredients and with the amount of aluminum powder selected to produce 0.02-0.08% titanium, less than 0.002% boron and less than 0.10% aluminum in the weld metal.