Abstract: An arc-melting method is taught for the formation of metallic-second phase composite materials. The method involves the formation of an intermediate composite material comprising a relatively high loading of second phase particles dispersed in a metal matrix. This intermediate material is then combined with an additional amount of metal and arc-melted to form a final composite comprising a lower loading of the second phase particles dispersed in a final metallic matrix. The final metallic matrix may be comprised of a metal, metal alloy, or intermetallic, while the second phase particles may comprise ceramic materials such as borides, carbides, nitrides, silicides, oxides or sulfides.

Abstract: An outer surface of a resistance welding electrode tip is coated with a layer of an electrically conductive ceramic material. A preferred layer contains tungsten disulfide applied by chemical vapor deposition.

Abstract: A method and apparatus for resistance welding in which, while both or one of the electrode center axes of a pair of opposing electrodes is inclined with respect to the electrode forcing axis, the electrode tip of the electrode is intermittently pivoted about the electrode center axis for welding. The contact between the electrode tip and workpiece is moved at a preset number of welds to define a next contact surface on the face of the electrode tip, and thus the number of welds (electrode tip life) is considerably improved.

Abstract: A spot welding electrode includes a plurality of alternating, co-axially first and second sections, the first sections having a first predetermined sized cross section. Each first section has an undercut portion tangential to the second section which defines a shear line. The second sections have a second predetermined sized cross section smaller than the cross section of the first sections. The outer sides of the second sections form undercut areas between the outer sides of adjacent first sections. The outer sides of the second sections act as cleavage surfaces which remove excess material formed at the peripheral edges of the adjoining first sections caused by successive deformation of the first sections during repeated welding operations.

Abstract: An electrode for a plasma arc torch and a method of fabricating the same are disclosed, and wherein the electrode includes a copper holder having a lower end which mounts an emissive insert which acts as the cathode terminal for the arc during operation. Where the torch is used in an oxidizing atmosphere, the copper holder tends to oxidize, and the arc tends to attach to the oxidized copper rather than the insert, which results in the rapid destruction of the holder. To prevent this destruction, the present invention incorporates a sleeve of silver or other metal having a relatively high work function, and which is positioned to surround the insert and form an annular ring on the lower end surface of the holder and thus to surround the exposed end face of the emissive insert. The annular ring serves to prevent arcing from the copper holder, and so that the arc is maintained on the insert.

Abstract: The invention concerns an electrode for the resistance welding of sheets of surface-treated steel. A thin disk of high melting-point metal is permanently attached to the electrode's shaft or cap at the contact surface. The grain of the high melting-point metal is oriented at an angle to the axis of the electrode and the rolled-out material has a flattened grain.

Abstract: Resistance welding electrodes and processes using the same are provided. The electrodes have a base portion and an integral nose portion projecting therefrom, with the nose portion terminating in a welding tip face. The nose portion tapers inwardly between said base portion and said welding tip face with a concave profile taper such as a frustum of a vortical surface. The electrodes used may be made up of a conventional copper material having copper combined with one or more metals selected from the group consisting of chromium, zirconium, cadmium, cobalt, nickel, beryllium, tungsten, aluminum, tungsten carbide, iron, and molybdenum; or, may be made of essentally pure copper. The electrodes may be used in a welding process, which provides for a generally linear increase in current stepping with reduced or eliminated conditioning of the electrodes.

Abstract: A soldering apparatus includes a holding device, which is composed of a ceramic material and fits over and covers partially, a thermod having an electrically grounded conductor portion to distribute heat uniformly to a soldering surface. The soldering apparatus is moved so that the thermod engages the surface to be soldered. Thermal energies are then uniformly transferred by the thermod to heat the connecting joint to soldering temperature and for heating a solder bead for soldering purposes. After soldering, the apparatus is retracted, or the current is turned off, to permit the surface to cool.

Abstract: A plasma torch electrode has a copper outer shell on an inner portion of which is provided a more durable composition of a silver alloy by pressing or casting to achieve longer lifetime under arcing conditions in air or oxygen while minimizing the cost of materials and fabrication.

Abstract: Electrodes used for spot welding of aluminium workpieces are improved by a combination of steps:(a) A roughened surface is formed on the electrode tip, preferably to an average roughness depth of 12 to 30 microns.(b) also an artificial protective coating, e.g. a chromate-based coating or an anodic oxide film, is applied to the workpieces.(c) Optionally the nugget diameter in the initial welding set-up is arranged to be not more than 15% greater than the minimum acceptable.Features (a) and (b) act synergistically to increase the service life of the electrodes, typically to more than 2000 welds.

Abstract: Dressing device for the welding tips of a spot-welding machine consists of a single tool carried crosswise of a cylindrical opening in a tool holder. The tool holder has opposed slots supporting the tool, with one edge of the slots and therefore one side of the tool at the crosswise centerline of the opening. A cutting edge on that side of the tool and adjacent the tip dresses the tip to provide an essentially flat welding face. The holder and tool are rotated about the tip while the tip is held on an arm of a spot-welding machine. Preferably, when the dressing device is used in a high production situation, the tool is symmetrical and has a pair of outwardly-directed cutting edges on the centerline, simultaneously dresing two tips as they approach the tool from opposite directions.

Abstract: Resistance welding electrodes and processes using the same are provided. The electrodes have a base portion and an integral nose portion projecting therefrom, with the nose portion terminating in a welding tip face. The nose portion tapers inwardly between said base portion and said welding tip face with a concave profile taper such as a frustum of a vortical surface. The electrodes used may be made up of a conventional copper material having copper combined with one or more metals selected from the group consisting of chromium, zirconium, cadmium, cobalt, nickel, beryllium, tungsten, aluminum, tungsten carbide, iron, and molybdenum. The electrodes may be used in a welding process, which provides for a generally linear increase in current stepping with reduced or eliminated conditioning of the electrodes. The welding tip face has a convex curvature which may range between about a two inch and a eight inch radius of curvature, and which preferably has a radius of curvature of about four inches.

Abstract: A composite electrode for resistance welding of the present invention comprises an electrode made of a high-melting point metal or alloy, an electrode holder made of a copper alloy and an intermediate member made of a copper alloy, the electrode being undetachably inserted into the intermediate member which is detachably mounted in the electrode holder so that the contact surface between the end surface of the electrode and the electrode holder bears welding loads when pressure is applied to the electrode, whereby the electrode can be easily mounted or separated and centering of the electrode can be precisely performed.

Abstract: An ultrasonic transducer assembly for monitoring the quality of spot welds employs a transducer element joined to a support element and fitted within a conventional welding electrode assembly. The transducer assembly is biased against the interior surface of the welding electrode tip by a biasing element, preferably a compression spring. A sleeve, preferably composed of brass, surrounds the transducer element and is joined to the support element. A coaxial cable in communication with external instrumentation has a ground lead attached to the sleeve, and a signal lead attached to the transducer element.

Abstract: The endwise resistance welding of a weld coupling to a plate. The weld coupling is mounted in a collet which is mounted slideably in a cavity in a block of conducting material. In the standby condition of the apparatus the collet is urged outwardly of the cavity by a spring between the block and the collet. The end of the block at the entrance to the cavity and the outward end of the collet have frustro-conical or tapered surfaces tapered at the same angle to the common axis of the block and collet. The surfaces are face-to-face. This assembly including the weld coupling is mounted on the movable electrode of the welder. During welding this electrode is moved towards the cooperative electrode, on which the plate is mounted, compressing the weld coupling against the plate. Under the reactive forces from the coupling and plate, the collet is moved inwardly of the block causing the tapered surface of the collet to slide with a cam-like motion along the tapered surface of the block.

Abstract: A method for repairing interconnect interruptions with congruent preforms. Congruent preforms that bridge an interconnect interruption are utilized for repairing interconnects whose width lies in the range from 50 through 70 .mu.m and whose course is fashioned meander-like. Interconnects having a width of about 150 .mu.m can be repaired with previous repair methods. Due to miniaturization of the interconnects, a special method for monitoring the congruent alignment between the preform and the interconnect at the location of the interruption as well as for monitoring the symmetrical bridging of an interconnect interruption is needed. This monitoring method occurs by monitoring with video camera, whereby the location of the interconnect interruption and the environment thereof, a preform that is congruent therewith, and the positioning of this preform relative to the interconnect interruption are viewed at different positions.

Abstract: A welding electrode arrangement comprising an inner electrode and a plurality of electrically interconnected outer electrodes defining a closed figure about the inner electrode, the outer electrodes being resilient in a direction substantially parallel to the axis of the closed figure, the outer electrodes further being in the form of a plurality of inwardly directed fingers extending from and integral with an outer connecting rim.

Abstract: The gun arm has a tail end portion provided with a flange with notches therein and a tapered portion extending rearwards from the flange. The arm holder on the gun body has a tapered hole formed to allow the tapered portion to be fitted thereinto via a receiving recess. Locking projections corresponding in shape to the notches of the flange are provided along the inner circumference of the opening end of the receiving recess. The exchange apparatus includes a gun arm indexing magazine with a plurality of gun arm holders, and a transfer device for transferring gun arms back and forth between the magazine and the welding gun.

Abstract: A method for repairing interconnect interruptions. Faults at the interconnects occurring in manufacturing processes of printed circuit boards were previously repaired with suitable methods. The fashioning of the interconnects in a meander form and their miniaturization requires a completely new procedure. The dimensions of current interconnects amount, for example, to: width.times.height=70 .mu.m.times.20 .mu.m. For repairing such interconnects that are usually arranged in extremely tight proximity on an interconnect carrier, it is necessary to position preforms utilized for repair absolutely congruently on the interconnect interruption and to hold them until the joining zones are completely formed between the preform and the interconnect. This is achieved by use of an insulating foil having work windows and by use of a preform panel that contains a plurality of preforms.

Abstract: Electrodes for use in spot welding which can spot-weld a metallic material having a large electric conductivity and a large thermal conductivity with a small electric current. A cup-shaped cap made of material having a small electric conductivity, a small thermal conductivity and a high melting point temperature as compared to the material to be welded, for instance, made of titanium, is fitted arond a tip end portion of an electrode main body. The top surface of the cap is formed in a spherical shape having a large radius of curvature, and a depression is formed at the central portion of the top surface. The thickness of the top wall is thick at the central portion and thin at the peripheral portion. Plating of soft metal having a better thermal conductivity than the electrode main body is applied onto the entire inner surface of the cap coming into contact with the electrode main body.

Abstract: A cutter and gear assembly for simultaneously dressing a pair of spaced aligned welding electrode tips comprise a housing with a power-rotated gear journaled thereon for rotation upon a first axis and having an axial bore at one end terminating in an annular seating flange and adjacent its other end having an annular groove. A dressing tool cutter assembly is axially nested within the gear, bears against the seating flange and has a plurality of axially elongated arcuate drive tangs nested within corresponding drive grooves within the bore. A snap ring is anchored within the annular groove and retainingly engages the cutter assembly. The cutter assembly includes a pair of symmetrical outwardly opening cutting elements upon its opposite sides, each cutting element including a plurality of angularly related inclined cutting edges having a profile corresponding to the contour of a pair of aligned electrode tips adapted for axial projection into and against the cutting elements upon the first axis.

Abstract: A coating for improved resistance welding of galvanized steel parts or sheets comprises a binder, and a metal phosphide pigment, preferably a ferrophosphorus pigment, having a particle size of from about 0.1 to about 30 microns. The pigment can also include up to about 40% by weight of an additional metal such as tin, aluminum or lead, which can be combined with the metal phosphide in pigment form or deposited onto the surface of the particles. The coating can be applied to either the faying or non-faying surfaces of the galvanized steel, or to the resistance welding electrode, and may be removed, if desired, after the welding operation.The advantages of the present invention include a significant reduction in welding current and an increase in the weldability lobe width, a restoration of the dynamic resistance beta peak, and an increase in electrode life.

Abstract: A tool for use in dressing the electrode tips of a welding machine. It is to be used in combination with conventional rotary dressing tools whereby one person can apply sufficient pressure on the tool to properly dress the welding tip. It consists of a clamping device to attach the tool of the invention to an electrode shank, and an adjustable lever arm to apply pressure to the dressing tool against the welding tip.

Abstract: Electrodes for use in electric resistance welding and a method of making such electrodes are disclosed. The electrodes are each shaped to define a tip surface for contact with a workpiece during welding. In one embodiment, each electrode comprises an electrode body of copper and a layer of titanium carbide on the body defining said tip surface. The titanium carbide layer is fused to the electrode body by a spark-fusion technique and forms a unitary electrode with the body. This form of electrode has been found advantageous in terms of minimizing "pick-up" of workpiece material during welding, and distortion of the electrode.

Abstract: The electrode comprises an electrically conductive body including, at least at its active portion, a sintered layer of silver powder having a particle size from 1 to 10 microns and crystalline graphite.

Abstract: In a spot welding to effect welding overlaid metal plates clamped by two opposite electrodes to which greater current is applied, tips of the electrodes are frustoconically shaped. Rotative tool (1) having recesses (H, J) respectively of reverse frustoconical shapes is provided with edged portions of notched portions formed by notching radially the peripheral wall thereof and through holes provided at the notched portions. Cut powder generated when the electrodes are cut is dropped off downward from the through holes. Tip ends on ceiling surfaces of the electrodes are cut at the same time by edged portion formed at upper edges (3) provided at the diameter of an extended portion (61) formed by extending over perforated bottoms of the recesses.

Abstract: A welding resistance electrode chip of this invention comprises a front end to be brought into contact with a substance to be welded, an intermediate cylinder disposed on and in contact with the tail end of front end, and a main cylinder having a closed end disposed on and in contact with the tail end of front end and the tail end and the inner wall of intermediate cylinder. It is sintered and molded out of appropriate copper-based powder materials respectively satisfying the requirements of portions thereof: The front end is made of a powder material having good thermal shock resistance and wear resistance, the intermediate cylinder is made of a powder material having high tenacity to suppress the deformation of the front end, and the main cylinder is made of a powder material having high conductivity. Therefore, the durability of resistance welding electrode chip of this invention has been improved remarkably, and the operation rate of equipment has been improved.

Abstract: A spot welding machine comprising a first electrode and a second electrode opposed to the first electrode, whereby a workpiece, including, e.g., a conductor wire coated with a heat-resistant resin film and a terminal to be welded to the conductor wire, is subjected to electric-resistance welding in a manner such that the workpiece is held between the first and second electrodes. In the spot welding machine according to the present invention, a third electrode is interposed between the first electrode and the workpiece so that one distal-end side face of the third electrode abuts closely against a workpiece engaging end of the first electrode, and that the other distal-end side face of the third electrode is in contact with the workpiece. The proximal end of the first electrode is connected to a first terminal of AC power source means, and the respective proximal ends of the second and third electrodes are connected to a second terminal.

Abstract: An apparatus is provided for the automatic lapping of welding robot electrodes including means for driving a lapping tool with a rotational movement, reciprocal or not, said tool being mounted on a support mounted for pivoting, with respect to a frame, about an axis parallel to the axis of the electrode or electrodes.

Abstract: A method of electric arc treatment of materials by constantly restored solid and hollow electrodes in plasma-forming mixtures including hydrocarbons and carbon oxides, whereby carbon is deposited on an initial electrode (2) to form said constantly restored true-carbon electrode (1). Treatment is performed at a temperature of contact of the initial and true electrodes (2,1) not exceeding the temperature of carbon sublimation.

Abstract: A welder head comprises a pair of welding electrodes arranged opposite to each other through workpiece to be welded, an electrode holder including a sliding member for holding one of welding electrodes and a support member for supporting the sliding member slidably in an opposing direction of welding electrodes, a pressure mechanism for pressing the one of the welding electrodes toward the other of the welding electrodes through the electrode holder, an elastic member for urging the sliding member toward the opposing direction of the welding electrodes, and a U-shaped electricity feeder provided between the one of the welding electrodes and the support member of the electrode holder and for supplying a welding current to the one of the welding electrodes.

Abstract: An improved hollow electrode 10 and hollow electrode working tip 14 for a gas tunsten arc welding apparatus is disclosed. The hollow electrode face is formed as a lune-shaped radial surface 16 having two tapered intersecting cone-shaped angled surfaces 18. The improved electrode working tip provides a controllable stable arc resulting in an improved weld.

Abstract: The contact wire (30) for a roller seam welding machine is provided on its front face with grooves (32) which are formed in the longitudinal direction of the wire and which are bounded by sharp longitudinal edges (34). The contact wire (30) is particularly well suited for welding metal sheets, the surfaces of which are heavily soiled or provided with coatings which are poor electrical conductors or electrically non-conducting. During the welding operation, the longitudinal edges (34) cut open the sheets to be welded or their oxide layer or coating which is a poor electrical conductor or non-conducting, and render possible a direct passage of the welding current to the actual metal sheet. Dirt as well as semi-plastic and vaporized coating material are reliably carried away to the front and rear in the longitudinal grooves so that the contact wire (30) cannot "float" during the welding operation.

Abstract: Structural components, for example rotor components for a flow-dynamic engine, are first tacked to each other prior to final joining. The tacking is accomplished by a spot resistance welding or a high energy ray welding using a small welding material ball at each welding spot or location. The balls are supplied to a welding spot through a hollow, evacuated electrode of the resistance welding apparatus.

Abstract: An electrode holder is provided with an adjustment mechanism adapted to permit the manual adjustment of the electrode relative to the holder. The adjustment mechanism is accessible to an operator when the electrode and the holder are in place during a normal fusing operation, whereby the position of the electrode can be adjusted without having to remove the holder of the electrode itself.

Abstract: An electrode used in a plasma-arc torch has ridges formed on the side surface thereof for initiating a pilot arc. The required voltage for initiating a pilot arc is substantially reduced by employing this type of electrode. The ridges have much smaller radii of curvature which substantially enhance the local electric field strength responsible for creating the pilot arc discharge. The ridges are oriented substantially along the flow lines of the plasma gas so as to create the least disturbance. In one embodiment with spiral gas flow, this results in helically oriented ridges. In another embodiment with straight gas flow, the ridges are parallel to the longitudinal axis of the electrode.

Abstract: A method and apparatus are shown for use in adding electrical connections to existing printed circuit boards. To this end, apparatus in the form of a multilayered pad is provided which has an adhesive layer over at least part of one face which is responsive to heat so that the pad can be bonded by heat to the surface of a printed circuit board. The other face of the pad includes a layer of stainless steel to which nickel wire can be stitched, or welded. A method according to the invention includes cutting a sheet of pads into individual pads, placing a plurality of pads, adhesive side down, on the surface of a printed circuit board, heating the pads to bond them to the board, and stitching (welding) wire to a succession of pads to complete a series of new connections. Some pads include plated-through-holes enabling connections to be completed from the pads to existing circuitry on the boards and to components mounted in the holes by the use of flow soldering techniques.

Abstract: An electric resistance welding apparatus is shown for attaching insulation to duct work comprising a supporting anvil with a surface for supporting a sheet metal duct work with a covering sheet of insulating material and a movable hammer member spaced from and movable relative to the anvil. The hammer member has one or more magnets for supporting a resistance welding pin and is movable to drive the pin through the insulating material to engage the sheet metal duct work. The hammer member and anvil are connected in an electric welding circuit to supply current from the hammer through the pin to the anvil to fuse the end of the pin to the sheet metal with the head of the pin holding a washer tightly against the insulating material. The hammer member and anvil are both copper with recesses having cylindrical copper electrode members removably positioned therein. In one embodiment, the hammer member recess is deeper than the copper electrode member, and the magnet fits the recess behind the electrode member.

Abstract: An electrode holder for conducting welding current from a power source via a base plate, a hollow body, and an electrode shaft which is slidably supported within and projects outwardly of the hollow body. The shaft has an enlarged head axially slidably supported within the hollow body and carrying thereon an electrical contact structure which is spring-urged for uniform slidable contact with both the head and the hollow body to effect efficient and uniform transfer of current therebetween. The head has channel-like recesses extending transversely on opposite sides thereof, and an identical contact structure is associated with each recess. The contact structure, in the preferred embodiment, includes a pair of contact blocks disposed adjacent opposite sides of the respective recess and spring-urged apart so that oppositely directed side surfaces on the blocks are slidably engaged with opposite side surfaces of the head to define a current transfer path.

Abstract: A male spot welding electrode includes a weld end portion having a generally flat contact surface and a tapered mounting portion containing an inlet bore. The inlet bore communicates with an internal cavity, containing cooling fins, for coolant fluid flow. The diameter of the internal cavity is made larger than the diameter of the inlet bore in order to maximize the cooling surface for the dissipation of heat generated during repeated welding operations. The male spot welding electrode is produced from a single billet of copper material through a process of back-extrusion and swaging.

Abstract: An apparatus for receiving and holding tools, specifically resistance welding units, carried by a robot programmed to execute certain movements including the placing of these tools at a specific location, including a base, for a vertical frame having a series of radial supports which can be rotated about a vertical axis and immobilized in positions in which the radial supports are disposed opposite various work stations, and respective mechanisms for decoupling a tool from the robot and for coupling a tool to the robot, so that at any one time the robot only carries one tool while other tools which may be used by the robot are freely available for repair and maintenance without interrupting the operation of the robot.

Abstract: A resistance welding electrode includes a barrel-shaped portion having a cooling water passage defined therein and extending closely to an end surface thereof, and a cylindrical projection integrally formed on the end surface of the barrel-shaped portion. The cylindrical projection has a helical groove defined therearound, and may additionally have another helical groove defined therearound parallel to the first-mentioned helical groove in 180.degree.-out-of-phase relation thereto. The cylindrical projection may have an axial slot defined in its circumferential surface across the helical groove.

Abstract: A spot welding electrode and method of assembling the same. The electrode includes a cap having a hollow cavity with an open bottom end and a closed tip. A plurality of circumferentially spaced fins are formed interiorally in the cap and extend inward from the side wall of the cap. The upper ends of the fin meet and have a spherical domed shape. The bottom ends of the fins are spaced from the bottom end of the cap to form a coolant flow path within the electrode. A shoulder is formed on the bottom wall of the electrode and mates with and is joined to a complimentary formed shoulder on the upper end of a shank to mount the cap to the shank.

Abstract: A plasma burner comprises an electrode holder which carries a tubular outer electrode and a coaxially arranged central electrode, and an electrical current supply source, which can be coupled via current feeders to the outer and central electrodes respectively. Also a device is provided for feeding gas into the region of the electrodes, between which an arc is produced for plasma formation. The tubular outer electrode has a first cooled, arc-inactive tube section, consisting of electrically conductive metal, and an adjoining second arc-active uncooled tube section, which consists of heat-resistant and electrically conductive material, and which is releasably connected to the first tube section. The arc passes between the second tube section and the neighboring arc-active section of the coaxial central electrode.

Abstract: A high frequency resistance welding system having a pair of jaws which are pivotally mounted together and are adapted to clampingly engage the work to be welded therebetween. Each jaw has two arms and each arm has a welding tip which engages the work. The welding tips on the arms on one jaw register with the welding tips on the arms on the other jaw. A high frequency alternating electric power source is connected to the first jaw so that the direction of current flow in one arm of the first jaw is opposite from the direction of current flow in the other arm of the first jaw so that the magnetic field caused by the current flow through one arm is substantially offset or cancelled by the current flow through the other arm of the first jaw. In addition, each welding arm is preferably L-shaped thus having an elongated shank with the welding tip at one end of the shank.

Abstract: A method and an apparatus for reconditioning worn electrodes for resistance welding. The worn electrodes are pressed into a die by a punch and thus restored to their original shape or given a different shape.

Abstract: A device for "dressing" welding electrode tips is disclosed. The device utilizes an integrally formed air motor, retained within a housing member, to drive a gear train which rotates the welding tip cutters. The air motor is actuated by relative longitudinal movement, in either direction, between the housing member and a carriage member which acts as the base for the device. The longitudinal axis of the air motor is parallel to the direction of travel of the housing member with respect to the carriage member thus eliminating the need for bevel gears in the gear train.

Abstract: A fusing machine and method employ a first electrode which defines a fusing station and a second electrode which is movable toward and away from the first electrode. Two wires which have been fused together at the fusing station are automatically cut without removing the fused wires from the fusing station prior to cutting them. Also disclosed is an electrode set including a first electrode having an inwardly tapered slot sized and shaped so as to releasably capture wires to be fused and a second electrode having a straight-sided tip sized and shaped so as to be freely movable into and out of the slot in the first electrode.

Abstract: Electrical Discharge Machining (EDM) utilizes electrodes made out of carbon, for example, in place of cutting tools. The shape of the electrode determines the shape of the part being machined. The EDM process wears down the carbon electrode cutting tool. By adhering fresh carbon material to the base of a carbon electrode as it wears down with a graphite and metallic powder-filled adhesive, the electrode can continue to be resurfaced indefinitely, thereby eliminating waste. In order to hold the carbon electrode more securely during initial shaping of the electrode, a metal base plate is used which is formed so that a portion of it fits into a cavity in the base of the carbon electrode. The carbon electrode is held fast to the metal base plate by countersunk bolts that engage threaded holds in the base plate. Flushing channels are provided through the metal base plate. Metal tooling clamps engage the metal base plate to hold it and the carbon electrode firmly against a tooling bed.

Abstract: A first electrode with a first clamping surface and a second electrode with a second clamping surface are moveable towards and away from each other during working cycles of the apparatus. The first and second clamping surfaces face each other and serve to securely clamp a workpiece to be welded and to supply an electrical current required for this operation. The second clamping surface of the second electrode is larger than the first clamping surface of the first electrode, and radial displacing members are provided to displace the second electrode with respect to the first electrode between successive working cycles. This is necessary, particularly during welding or soldering series of small articles, in order to reduce the frequency of wear due to heat accumulation and to reduce the need to frequently exchange the electrodes or electrode inserts carrying the clamping surfaces, which exchange is caused by the heat accumulation.