Abstract: A hydro-electrochemical power generator includes an interlayer having a first end and a second end opposite the first end, a first electrode in contact with the first end of the interlayer, wherein the first electrode includes a first material that is a corrodible metallic material, a second electrode in contact with the second end of the interlayer, wherein the second electrode includes a second material that is a corrodible metallic material, and at least one heat source coupled to one of the first electrode and the second electrode and configured to apply a temperature gradient across the first end and the second end of the interlayer, and wherein the first electrode and the second electrode are configured to output a non-zero electrical voltage in response to the application of the temperature gradient.

Abstract: Systems and methods for initiating and/or terminating a GMAW-P welding process are disclosed. A welding-type power supply may include a power conversion circuitry configured to convert input power to welding-type power, and a controller configured to control the power conversion circuitry based on a plurality of operating parameters. In examples, the systems and methods disclosed herein implement pulsed cycles with one or more increased output parameters (such as current, pulse width, etc.) in order to jump start a pulsed welding cycle at a cold start (i.e. at initiation of a welding process), and thereby prevent a ball forming and remaining on the end of an electrode wire as the welding process continues. In a similar manner, a pulsed cycle with one or more increased parameters can be used to terminate the welding process, also preventing the ball forming and remaining on the electrode wire.

Abstract: A method includes positioning a braze material along a defect of a component of a turbine system, positioning a cover over the braze material, and focusing a heat source on the cover to melt the braze material along the defect.

Abstract: A welding tool for a robot welds together a first component and a second component by using a metallic welding element disposed within a through-hole in the second component. The welding tool includes a welding torch attached to an arm, an element pusher that is attached to a distal end of the arm and disposes the held welding element between the welding torch and the through-hole and disposes at least a part of the welding element within the through-hole, a component pusher attached to the distal end of the arm and movable in an axial direction of a distal end of the welding torch, and a driving device that presses the component pusher against the second component. The element pusher is movable in the axial direction relative to the component pusher.

Abstract: An impact panel for protecting mining equipment may include a plurality of ceramic tiles affixed to a base plate. The impact panel may further include at least one fixing hole disposed within the plurality of ceramic tiles and the base plate with a metal frame disposed around an outer peripheral edge of the plurality of ceramic tiles that is also affixed to the base plate. The impact panel may have at least one plug disposed inside the at least one fixing hole to seamlessly cover the at least one fixing hole. The panels may also be wired with sensors that will communicate with process control circuits allowing data collection on remote process and remote mining equipment.

Abstract: The disclosed wall includes several narrow aluminum sheets and posts that are Friction Stir Welded (FSW) into a sidewall. The length of the wall is the summation of the narrow sheets' width, and the walls width is the narrow sheets' length. Several aluminum posts are spaced along the wall's length direction in order to improve the stiffness and strength of the wall. When welding the aluminum sheets and posts together, the sheets are placed under the posts and jointed tightly together through FSW. With the high-speed spinning of the stirring pin, the post and sheet melt and form into a compact solid phase weld seam under the extrusion of the welding head. When welding two aluminum sheets and one post together, the two sheets are placed edge-to-edge or slightly overlapped. The post is then placed over the sheet joint and the stir-welding head melts portions of the post and the two sheets simultaneously.

Abstract: An axle tube assembly includes an axle tube, a first tube reinforcement apparatus disposed in the axle tube at one end and a second identical tube reinforcement apparatus disposed into the axle tube at the second end the reinforcement apparatuses welded in place to the axle tube, a first spindle assembly coupled to the first tube reinforcement apparatus, a second spindle assembly coupled to the second tube reinforcement apparatus, and an elongated connector rod or tube connected to the first and second reinforcement apparatuses inside the axle tube and disposed between the reinforcement apparatuses the first and second spindle assemblies having spindle bodies welded to the cylindrical ends of the axle tube.

Abstract: An example system includes: a hand-held welding tool that is manually placed in a welding position, wherein the hand-held welding tool is configured to be activated to cause a contact tip or a welding heat source to automatically move from a first position and to second position during a welding operation, and wherein a welding arc is automatically and repeatedly turned off and on while the contact tip or the welding heat source moves from the first position to the second position to make a plurality of welds between the first position and the second position, wherein, as a travel speed decreases, a time period between each arc on time increases to make equally spaced welds.

Abstract: A rotating are sensor is provided. The rotating arc sensor includes a motor, a connecting rod for driving a welding gun to perform an annular movement, a sliding assembly for supporting a weight of the connecting rod and supporting a free movement of a first end of the connecting rod, and an eccentric oscillating member for driving a second end of the connecting rod to perform the annular movement, wherein a center of a rotating shaft of the motor is provided with a hollow cavity capable of communicating with both ends of the motor, the sliding assembly is disposed at a top end of the motor, and the first end of the connecting rod protrudes out of the top end of the motor through the hollow cavity and is connected with the sliding assembly. The eccentric oscillating member includes a first flange and a second flange.

Abstract: A component assembly system comprises a first robot arm having a first end-of-arm tool mounted thereon and adapted to grasp a first subcomponent; a second robot arm having a second end of arm tool mounted thereon and adapted to grasp a second subcomponent. A system controller is adapted to control the first and second robot arms and first and second end-of-arm tools to position the first and second subcomponents relative to one another. A first interlocking mechanism is mounted onto the first end-of-arm tool and a second interlocking mechanism is mounted onto the second end-of-arm tool, wherein the first and second interlocking mechanisms engage one another and lock the first end-of-arm tool to the second end-of arm tool, thereby locking the first and second subcomponents into an initial position relative to one another.

Abstract: Provided is a spot welding machine able to perform spot welding in which the desired nugget size is formed while suppressing spatter even if the strengths or thicknesses of the metal sheets change, the machine comprising: a pair of electrode tips, a pair of pressing members arranged around the tips, a first power supply, first and second drive mechanisms, and a pressing force control part, wherein the tips and the pressing members are respectively arranged facing each other so as to be able to sandwich a set of sheets between them, the first drive mechanisms give pressing forces pressing the tips against the sheets, the second drive mechanisms give pressing forces pressing the pressing members against the sheets, and the control part independently controls the pressing forces given by the first and second drive mechanisms.

Abstract: The present disclosure relates to an induction heating device. A loaded-object sensor according to the present disclosure is arranged concentrically and centrally in the working coil. Thus, the sensing coil and the working coil are adjacent to each other. When a current for the heating operation is applied to the working coil, an induction voltage is generated in the sensing coil by magnetic force generated by the current applied to the working coil. According to the present disclosure, a resistor circuit is used to reduce the induction voltage generated in the sensing coil when the heating operation of the working coil is performed.

Abstract: A resistance point welding apparatus for fixing a turbulence installation body to an inner wall of a steam generator pipe, having a welding head, which is introduced into the pipe and includes a lance having an electrically conductive material, a point welding electrode, which projects out of the lance in the radial direction, an effective element and an insulation body, which is opposite the point welding electrode in the radial direction and is moved by the effective element, is provided. The lance is tapered at a defined distance from the welding head end such that the insulation body and the point welding electrode press the turbulence installation body against the inner wall of the pipe when the effective element is activated. When a welding stream is impressed on the lance, a point-like welding stream flows via the point welding electrode to a counter electrode arranged outside the pipe.

Abstract: In a spot welded joint according to an aspect of the present invention, with respect to a rectangular planar region of 100 ?m×100 ?m which is perpendicular to a sheet surface of the plurality of the steel sheets and which centers around an inner point spaced away by 100 ?m in a direction parallel with the sheet surface from an edge of a nugget, in a case of measuring a P concentration at a pitch of 1 ?m to obtain measured values of the P concentration at 100×100 of measurement points, and in a case of repetitively calculating an average value of the measured values of the P concentration at 20 of the measurement points which are adjacent to each other and which are arranged in a row in the direction parallel with the sheet surface among the 100×100 of the measurement points while shifting each one point to obtain 81×100 of the average values, the number of the average values which are more than two times an average P concentration is 0 to 100.

Abstract: A welding device provided for welding automobile parts received in a pallet to a vehicle body includes: an aligner configured to grip and align the parts received in the pallet; a mover configured to move the aligner to take out the parts and let the taken out parts adhere to an installation position of the vehicle body; and a welding machine configured to weld the adhering portion between the parts and the vehicle body.

Abstract: A method of laser welding where two steel sheets are welded by a laser beam after the two steel sheets are overlapped with a predetermined gap is disclosed. The method includes: a stitch welding step where a laser beam of focal region is irradiated along a welding portion of the upper steel sheet and the lower steel sheet such that a molten slot is formed at the upper steel sheet along the welding portion and an heat expansion portion is formed at the lower steel sheet along the welding portion by thermal conduction; and a pattern welding step where the laser beam of focal region is irradiated along the welding portion with a predetermined pattern such that an edge of the molten slot formed at the upper steel sheet is melted together with the heat expansion portion of the lower steel sheet so as to form a molten pool.

Abstract: An object of the present invention is to provide an induction heating cooker with improved assemblability, and with which a reduction in the temperature sensing precision of an infrared sensor can be suppressed and a reduction in the thickness of the induction heating cooker can be achieved. To this end, the induction heating cooker of the present invention includes a duct 33 that forms a cooling air path for guiding the cooling air produced by the air blower 32 to a control circuit 27 and to an infrared sensor 26. The infrared sensor 26 and the control circuit 27 are disposed at positions lower than the top wall of the duct 33.

Abstract: A surgical system and method for manipulating tissue. A steerable assembly comprises a steerable instrument and a deformable conduit. The steerable instrument comprises a control element and a deflectable portion operatively connected to the control element. The steerable assembly is directed through an access cannula such that at least a portion of the steerable assembly protrudes from the distal end of the access cannula. The steerable instrument is actuated to move a deflectable portion of the steerable instrument and a distal portion of the deformable conduit away from the longitudinal axis of the access cannula so that the deformable conduit assumes a deformed position. The steerable instrument is retracted from the deformable conduit.

Abstract: A method providing a manual welding apparatus configured to supply a welding wire to a welding gun. The welding gun has a trigger and an opening where the welding wire extends when the trigger is activated. The method also has a computer with a user interface that includes an automatic wire retract program. The program monitors the welding gun and determines when the trigger is disabled. The program indicates when a first condition is satisfied and retracts the welding wire so the welding wire does not extend from the opening of the welding gun.

Abstract: The present invention includes a welding system that has at least two metal inert gas (MIG) welders configured to perform a cooperative pulsed MIG welding process. The welding system also includes at least one communications link connecting the at least two MIG welders to deliver at least one of subordination commands and superiority commands to either of the at least two MIG welders to synchronize the cooperative pulsed MIG welding process.

Abstract: An electric spot welding gun (10) includes: a servo motor (40); a push rod (50) that advances and retracts in response to rotation of a rotor (43) of the servo motor; a drive-side electrode tip (71) that is mounted to a drive-side arm (70) fixed to a leading end of the push rod; and an encoder (60) that detects the rotation angle of the rotor of the servo motor, the position of the electrode tip being offset relative to the push rod, in which the rotor and the encoder are disposed in parallel to each other in an offset plane on which the electrode tip is offset relative to the push rod, at an attitude in which a trailing end (44) of the rotor on a side opposite to a push rod side thereof and an input end (64) of the encoder are facing in the same direction.

Abstract: A method for metalworking using an adjustable vacuum and support system for evacuating particulate matter, smoke, excess gas, and molten metal from a work area during welding and for providing adjustable support to a welding head. The vacuum system has a vacuum head and a vacuum nozzle. An adjustable mounting bracket has a first portion fixed to the vacuum head and a second portion securable to the welding head. The bracket arrangement establishes pivotal and slidable couplings between the welding head and the vacuum head. The vacuum nozzle has a support surface for being rested on a surface of a workpiece to support the vacuum head and the welding head. The support surface can be a base bevel surface at the tip of the nozzle, and an opposed suction bevel surface can have a nozzle aperture interposed therealong.

Abstract: There is illustrated and described a method for joining a composite sheet metal member to an additional component, the composite sheet metal member having at least two outer covering metal sheets and at least one non-metal layer which is arranged between the covering metal sheets and the additional component having at least one outer metal layer, wherein the composite sheet metal member and the additional component are moved so as to overlap each other between two electrodes of a resistance welding unit. In order to be able to join composite sheet metal members in an operationally reliable manner by means of resistance welding, there is provision for an electrically conductive dummy element to be moved into abutment with an outer covering metal sheet and for at least one current path between the two electrodes to be closed by means of an electrically conductive dummy element.

Abstract: A spot welding system according to an embodiment includes a spot welding robot and a control device. The spot welding robot has a plurality of joint axes and includes a plurality of motors in correspondence with the joint axes. The control device drives the motors. Furthermore, the control device includes a capacitor that accumulates regenerative electric power generated from the motor.

Abstract: A method of controlling a spot welding system used for attaching an inserted element in a hollow member is provided. A position of the inserted element in the hollow member is determined, the position of an attachment point is determined from the position of the inserted element in the hollow member, and a spot welding operation is performed at the attachment point. Further, a spot welding system for carrying out the method is provided.

Abstract: There is provided a pressure control method for a spot welding apparatus. Upon spot-welding a workpiece while applying a preset pressure to the workpiece by a pressure actuator through a movable electrode and a fixed electrode holding a workpiece and applying a preset sub-pressure by a sub-pressure actuator through a sub-pressure unit, the workpiece is pressed with an initial pressure by the movable electrode and the fixed electrode, and an initial sub-pressure is applied through the sub-pressure unit. After that, the setting pressure is applied to the workpiece by the pressure actuator through the movable electrode and the fixed electrode, and the setting sub-pressure is applied by the sub-pressure actuator through the sub-pressure unit.

Abstract: There is provided a spot welding apparatus. The apparatus includes fixed and movable electrodes to hold and press a workpiece therebetween, and a sub pressure force applicator having a sub pressure unit that moves and selectively stops at a plurality of positions including a sub pressure position where the sub pressure unit is adjacent to the fixed electrode and in contact with the workpiece so as to apply a sub pressure, and a sub-pressure-non-requiring position where the sub pressure unit is located away from the workpiece. Spot welding is performed by applying current between the electrodes while holding the workpiece between the fixed electrode together with the sub pressure unit located in the sub pressure position and the movable electrode. Spot welding is also performed by applying current between the electrodes while holding the sub pressure unit in the sub-pressure-non-requiring position and holding the workpiece between the electrodes.

Abstract: A one-side spot welding method for causing an electrode to contact a welding portion of a work-piece only from one side of the work-piece to weld the work-piece, the method includes a nugget forming process of applying welding pressure to the work-piece through the electrode, and causing the work-piece to be fully electrically conducted at a predetermined current value, and a slow-cooling process of applying welding pressure to the work-piece through the electrode from the one side, and causing the work-piece to be electrically conducted at a current value lower than the predetermined current value after the nugget forming process.

Abstract: A flange section 12b protruding in a radial direction of a ball screw shaft 6a is formed at a lower end portion of the ball screw shaft 6a, and a protrusion stopper 12a which abuts on the flange section 12b to prevent the ball screw shaft 6a from protruding out of the rod 7 is formed in a hollow section of the rod 7. On the lower side of the hollow section of the rod 7, there is formed a retraction stopper 13a which abuts on a lower end portion 13b of the ball screw shaft 6a to limit the refraction of the rod 7.

Abstract: There is provided a spot welding apparatus. The spot welding apparatus includes a fixed electrode and a movable electrode that clamp and press a workpiece formed of stacked plates of different rigidities, and a control pressing force applicator that causes a control pressing force applying actuator to bring a receiving unit provided at a distal end of a control pressing force applying arm into contact with the workpiece so as to apply a control pressing force to the workpiece. The control pressing force applying arm is made of a non-magnetic material.

Abstract: A welding device for a stretch bender is disclosed. The welding device for the stretch bender may include: an operating unit adapted to move forward toward or rearward from a bending die for shaping a shaped beam and mounted in front of the bending die; and a welding unit mounted at the operating unit and welding flange portions of the shaped beam that is completely formed by the bending die so as to prevent the flange portions from being overlapped with each other when extracting the shaped beam, the welding unit being movable forward or rearward against the operating unit.

Abstract: A bearing structure arrangement of a motor vehicle body is provided with a side panel structure adjoining a bulkhead, and a linking component secured thereto for accommodating a frame rail section located upstream from the side panel structure in the traveling direction. The linking component facing the frame carrier section includes, but is not limited to an attachment profile corresponding with the profile cross section of the frame rail section.

Abstract: A bonding apparatus of metal plates includes an upper mold having a first guide pathway formed vertically inside thereof; a middle mold having a second guide pathway formed vertically inside thereof, where the middle mold is disposed under the upper mold; a lower mold having a metal removing pathway formed vertically inside thereof, where the lower mold is disposed under the middle mold; a heating unit for heating the metal plates and a metal tape; a punch for applying a bonding load to the metal plates; a clamping unit that applies a clamping load for clamping the metal plates to the upper mold; and a bonding unit that applies the bonding load to the punch for bonding the metal plates.

Abstract: A spot welding method and a spot welding apparatus are provided. A stacked assembly of at least three workpieces is gripped between first and second welding tips. An inner workpiece positioned inside of the stacked assembly, of two of the workpieces that exhibit a maximum contact resistance in the stacked assembly, is electrically connected to a ground electrode, or to an electrode having the same polarity as the second welding tip near an outer workpiece positioned adjacent to the inner workpiece and facing outwardly from the stacked assembly, of the two workpieces. Then, electric current is applied from the first welding tip toward the second welding tip. In this case, first, the stacked assembly is pressed under a first pressing force, and then, the stacked assembly is pressed under a second pressing force which is greater than the first pressing force.

Abstract: When spot-welding a workpiece including a thin plate, a first thick plate, and a second thick plate, the workpiece is clamped by a fixed electrode in contact with the second thick plate, a movable electrode in contact with the thin plate, and control-pressure applying unit set adjacent to the movable electrode and in contact with the thin plate. Pressure is applied to the second thick plate by the fixed electrode, and pressure and control pressure are respectively applied by the movable electrode and the control-pressure applying unit to the thin plate. The pressure from the fixed electrode is controlled to be smaller than the pressure from the movable electrode. The current density between the thin plate and the first thick plate increases.

Abstract: Embodiments of the invention relate to a wound covering having a first strip-like element forming a first periphery and a second strip-like element that faces away from the first periphery, runs approximately parallel thereto, forming a second periphery, and is joined to the first strip-like element, there being formed between the first inner periphery of the strip-like element, facing away from the first periphery, and a second inner periphery of the second strip-like element, facing away from the second periphery, a drainage chamber, the depth of which in a depth direction extending at right angles to the periphery ensures a capillary action on bodily fluids received in the drainage chamber, in particular exudates.

Abstract: An electric spot welding gun (10) includes: a servo motor (40); a push rod (50) that advances and retracts in response to rotation of a rotor (43) of the servo motor; a drive-side electrode tip (71) that is mounted to a drive-side arm (70) fixed to a leading end of the push rod; and an encoder (60) that detects the rotation angle of the rotor of the servo motor, the position of the electrode tip being offset relative to the push rod, in which the rotor and the encoder are disposed in parallel to each other in an offset plane on which the electrode tip is offset relative to the push rod, at an attitude in which a trailing end (44) of the rotor on a side opposite to a push rod side thereof and an input end (64) of the encoder are facing in the same direction.

Abstract: Provided is a joint product of a steel product and an aluminum material, the joint product being formed by joining the steel product having a sheet thickness t1 of 0.3 to 3.0 mm with the aluminum material having a sheet thickness t2 of 0.5 to 4.0 mm by spot welding, wherein a nugget area in a joint part is from 20×t20.5 to 100×t20.5 mm2, an area of a portion where a thickness of an interface reaction layer is from 0.5 to 3 ?m is 10×t20.5 mm2 or more, and a difference between the thickness of the interface reaction layer at a joint part center and the thickness of the interface reaction layer at a point distant from the joint part center by a distance of one-fourth of a joint diameter is 5 ?m or less, and wherein the aluminum material is pure aluminum or an aluminum alloy material.

Abstract: In a battery pack in which multiple battery cells are arranged in one or multiple rows in an electrically insulating case and an electrode of each battery cell is coupled to an electrode of another battery cell through a connecting metallic plate, the connecting metallic plate made of copper is disposed on a positive electrode of each battery cell and on a negative electrode of another battery cell to form a lap joint, and a weld is formed in each of one predetermined position on the connecting metallic plate 3 above the positive electrode and another predetermined position on the connecting metallic plate above the negative electrode by applying arc spot welding. The depth h of weld penetration in the weld is greater than the thickness T1 of the connecting metallic plate and smaller than the thickness T1 plus the thickness T2 of the positive electrode or the negative electrode, that is, T1<h?(T1+T2×4/5).

Abstract: Buried arc welding is employed to fuse together a first component, a second component, and a third component or an underlying portion of the second component, the first and second components in butting relationship along a butting joint and the third component or underlying portion of the second component lying beneath the butting joint.

Abstract: Method of tying two or more components together using a fastener. Each component is provided with a hole and the components are placed so that the holes overlap one another in order to receive the fastener in the holes. The fastener is placed in the holes and mechanically pressure-loaded and heated in order to deform the fastener to tie the components together. The fastener is heated essentially only during the fastener deformation phase in order to minimize the heat transfer from the fastener to the components being tied.

Abstract: The invention relates to a welding method involving the use of a non-fusing electrode (12) according to which the electrode (12) is provided with power from a power source once the arc (11) between the electrode (12) and the workpieces (13, 14) to be joined has been ignited. The invention also relates to a tack welding method. The aim of the invention is to improve the quality of the weld seam in the starting phase of the welding process. To this end, the invention provides that before the actual welding process, a start program (22) is performed without the introduction of a filler material during which the electrode (12) is supplied with pulsed power in the form of current or voltage pulses over a presettable length of time (23) whereby causing the liquid molten bath to oscillate or vibrate, and that after the execution of the start program (22), the actual welding process is carried out during which the electrode (12) is preferably supplied with constant power.

Abstract: A method of welding continuous or intermittent lap-penetration joints using a gas metal buried arc (GMBA) welding process. A first component is GMBA welded to an underlying second metal component, by forming an arc between a consumable metal electrode and a surface of the first component, depositing metal from the electrode to the first component and producing a pool of molten metal which extends through the first component and into the second component. The molten pool metal solidifies into a weld that extends into the second component wherein the weld width at the interface between the components is at least equal to the thickness of the thinner of the first component and the second component. The arc is at least partially buried within the thickness of the first component and is moved in the direction of the desired joint location to produce a joint.

Abstract: A method and apparatus for welding includes one or more of a welding type power source, a feedback circuit, a wire feeder and a controller. The controller preferably has an eta control circuit responsive to the feedback. It also has a control loop having a response time responsive to the eta output. The controller detects whether or not the process is a fast-tack process, and controls the supply of power according to a first control scheme is the process is a fast-tack process, and according to a second control scheme if the process is not a fast-tack process. The controller sets the run-in wire feed speed as a percentage of weld wire feed speed, preferably obtaining the percentage from the weld wire feed speed potentiometer at start up. The controller enters a calibration mode at start up if a calibration pendant is attached and on. In the calibration mode calibration receiving values from the front panel potentiometers.

Abstract: An arc welding method for welding first and second sheet welding members (1, 2) requires a power supply (5) including two electrodes (3, 4). Welding points (13) on the first welding member are determined. An extrusion (132) is formed on the first welding member at each welding point. The extrusions contact the second welding member. The second welding member is attached to an electrode. One of the extrusions of the first welding member is connected with the other electrode. The power supply is turned on. Electric current flows from the extrusion to the second welding member, and much of air is ionized around the extrusion. Thus the extrusion is welded on the second welding member. Once all the welding points are welded on the second welding member, the first and second welding members are securely welded together.

Abstract: A treatment instrument includes a first coil and a second coil that is different from said first coil. The first and second coils are connected to each other. An operation wire is inserted in the first and second coils, and a tip end of the wire is connected to a treatment device. Upon movement of the wire, the treatment device operates. A method of manufacturing such a treatment instrument includes inserting one end of the first coil and one end of the second coil in a connection pipe from opposite ends thereof, exposing both ends of the connection pipe and corresponding portions of the first and second coils. The portions exposed to the arc columns are melted and connected.

Abstract: The invention describes a method of brazing workpieces (16) with a torch (10), in particular a plasma or welding torch, having an electrode (28), in which a transmitted and/or non-transmitted working arc supplied with power from a power source or a current source (2) is produced in order to generate a plasma beam from a delivered plasma gas, whereby at least one filler material (38) is fed to the seam region of the workpieces (16) to be joined. The filler material (38) is connected to the or to another power source or current source (39). To this end, one potential (40) of the power source or current source (39) is applied to the filler material (38) and the other potential (35, 41) to the workpieces (16). The power source or current source (39) is regulated in such a way that when the filler material (38) is lifted off the workpiece (16) an arc is prevented from being generated.

Abstract: A method and apparatus for welding includes one or more of a welding type power source, a feedback circuit, a wire feeder and a controller. The controller preferably has an eta control circuit responsive to the feedback. It also has a control loop having a response time responsive to the eta output. The controller detects whether or not the process is a fast-tack process, and controls the supply of power according to a first control scheme is the process is a fast-tack process, and according to a second control scheme if the process is not a fast-tack process. The controller sets the run-in wire feed speed as a percentage of weld wire feed speed, preferably obtaining the percentage from the weld wire feed speed potentiometer at start up. The controller enters a calibration mode at start up if a calibration pendant is attached and on. In the calibration mode calibration receiving values from the front panel potentiometers.

Abstract: A roller including an inner tubing and an outer tubing which is fixed relative to the inner tubing by welding the outer tubing to the inner tubing. The roller with weldments is particularly suitably for a nipped application.

Abstract: A welding apparatus spot welds two or more overlapping sheets having a coating, such as zinc coated steel or aluminum alloy with an oxide coating. A hole is formed in the upper sheet at the desired point of spot welding. A clamping cup of a plasma arc passes surrounds the hole and contacts the upper surface of the upper sheet. The torch heats the sheet, allowing entrapped vapors in the coating on the lower sheet to vent freely. Filler wire is added to fill the hole and to secure the overlapping sheets together. If the overlapping sheets are zinc coated steel, preferably the filler wire is copper based.