Showing papers on "Electric resistance welding published in 1970"

Resistance welding of sheet metal coated with layers

Abstract: The invention relates to a method for the resistance welding of sheet metal coated with layers, wherein firstly electrical contact is established between the sheets to be interwelded and between the welding electrodes and said sheets, and subsequently welding is effected across the coating layers The invention relates also to machines for carrying out this method

Automatic control mechanism for plasma welder

Abstract: An automatic control device for plasma arc welding by use of a plasma torch fitted with a cathodic electrode and a gas blow nozzle, said torch being movable relative to a welding stock which is arranged as an anodic electrode, said device being characterized by the provision of a photoelectric sensor arranged to measure the inclination angle of the tail flame part of the plasma arc emerging from the backside of the welding stock while the welding operation is going on, the electric output signal from said sensor being fed to an electronic control circuit adapted for control of any one or more of the welding parameters such as the relative travel speed between the torch and the welding stock, the rate of plasma gas supply and the rate of the welding current.

Welding control arrangement

Abstract: An apparatus for controlling the application of weld metal in electric calarc welding includes a mechanical scanning device upstream from the welding torch. The scanning device penetrates into the welding groove and measures at least one physical dimension thereof which is converted into signals for controlling the welding material feed.

Method for arc welding using individual pulse control for material detachment and acceleration

Abstract: A method of arc welding wherein the welding current delivered to the welding electrode is periodically caused to assume a plurality of essentially different amplitude values such that a waveform having at least a main and auxiliary amplitude is provided to the electrode. The main amplitude is provided to fuse and detach material from the end of the electrode while the auxiliary amplitude is used to accelerate the detached material to the weld puddle.

Method and apparatus for continuously making truss elements

Abstract: A method and apparatus for continuously making truss elements in successively formed unit lengths from supplies of web forming and chord-forming strip. A unit length of supporting web is shaped at a die station while in position overlying a longitudinal portion of chord member formed of the chord forming strip. The web is joined at a welding station by resistance welding to the chord. The shaping of the unit length of web imparts to the web a pair of alternate opposite bends separated by straight portions. The bends include flat portions for joining to chord members and the straight portions between the bends are shaped to a curved cross section to provide rigidity. The chord member is provided with outwardly projecting ribs which melt to form the weld when pressed between resistance welding electrodes. The forming dies and welding heads move from the path of the truss element as the truss element is intermittently advanced by a three-latch advancing mechanism.

Resistance welding electrode

Abstract: The useful life of a resistance welding copper electrode is significantly extended by plating on its tip a material having certain defined parameters and exemplified by nickel, berylium, cobalt and iron.

Apparatus for removing a weld upset

Abstract: A method and apparatus for automatically removing a weld upset formed between a pair of coaxial workpieces butt welded into an integral article by friction welding or the like. The method and apparatus include a shearing device positioned closely adjacent the abutting surfaces of the workpieces during welding and automatically drawn through the weld upset upon completion of welding to remove the upset.

Welding of explosive-plated metal sheets

Abstract: The present disclosure relates to a process and arrangement of elements for welding explosive-clad metal sheets which substantially eliminate the formation of cracks when the weld is exposed to mechanical stresses.

Connecting metal elements and products thereof

Abstract: A method of connecting metal elements by a resistance welding process to produce a high strength joint and particularly to connect a refractory type pre-formed carbide head to a shank of a dental bur formed from steel, and the product formed by such method.

Method and apparatus for automatic arc welding in a vertical position

Abstract: A method of arc welding in a vertical direction and an arc-welding machine for automatically performing the steps of the same are provided. According to the arc welding method of the invention, the advancement of a consumable electrode wire is accelerated and the welding voltage of the welding torch is increased as the torch crosses the centerline of a generally vertically extending weaving pattern it is caused to follow during a welding operation. After passing the centerline, the voltage is decreased to its original level, as it is on the return stroke also. This method is further improved by increasing the welding current of the torch slightly after increasing the welding voltage and further by decelerating or stopping the weaving motion at both sides and at the center of the weaving path of the wire. The apparatus for automatically carrying out this arc welding method comprises, in conjunction with an advancing consumable electrode wire and a welding torch adapted to follow a weaving path in a generally vertical direction, means for changing certain of the welding conditions, such as the advancing speed of the metal wire, the welding voltage and current, the weaving speed, and means for aligning the centerline of the weaving path or width to the welding centerline of a base metal.

Welding machine and method

Abstract: The invention relates to the welding of transverse rungs between longitudinal rods to form steel reinforcement, for concrete, known as ''''Bi-Steel'''' The rods are fed convergently and continuously through a resistance welding machine, the transverse rungs being successively positioned between the rods A pair of welding electrodes are thrust from opposite sides against the rods to clamp each successive rung in position during welding by sequential spot welding Each electrode travels around a closed path such that the electrode travels along with the rods when in contact therewith The contact between the electrodes and the rods is preferably rolling contact so that any discrepancy between the speeds of the rods and of the electrodes causes rolling rather than sliding of the electrodes along the rods The electrodes may be rollers mounted on rotating carrier discs between which the rods pass In one example each disc carries twelve roller electrodes each urged by a spring radially outwardly of the disc In another example two electrodes are used each mounted on a beam extending between a crank and a rocking arm

End weld control circuit

Abstract: A resistance drop welding control circuit includes apparatus operable in conjunction with the weld timer of a resistance welding machine for terminating the weld interval in response to a drop of the welding resistance value to a preselected fraction of its peak value. A buffer circuit driven by the weld timer provides an output during the weld interval. A transition timer energized thereby provides a first transition signal during the initial part welding interval during which resistance irregularities and instabilities are likely to occur and a second transition signal for the remainder of the weld interval. A signal proportional to the instantaneous welding resistance is applied to an end ratio detector. The second transition signal is applied to the end ratio detector to allow it to store the peak value of the resistance signal. After the minimum time normally required to achieve a good weld has passed a minimum weld timer energizes the end ratio detector in synchronism with the alternating power supply to the welding machine to cause the end ratio detector to provide an output upon concurrence of completion of a whole number of cycles of welding current flow and a drop in the instantaneous welding resistance to a preselected fraction of its peak value. An end weld circuit energized by said output thereupon causes the weld timer to terminate the weld interval. A quality indicator responds to termination of the weld interval by the weld timer prior to energization of the end weld circuit to indicate a possible defective weld.

Welding of wires to each other

Abstract: The invention relates to an improved means and process for welding wires and, more particularly, for welding lead wires to the ends of the magnet wire in small wire coils. The invention also embraces an improved welding torch using a small-orificed burner tip and providing a sheath of shielding inert gas around the welding flame. Improved fixture means is likewise provided for tensioning and holding the wires in intimate contact while welding or fusing. The fixturing includes a means holding one wire in tension and coiling the other thereabout. The torch is moved up to the wrapped wires to effect the weld by fusing the wires at a temperature such that the insulation first vaporizes, obviating the need for initial removal of the insulation by other means or methods. The fixture includes rotatable means to bring the two ends of the coil wire into position for making welds to the leads.

Method and apparatus for welding an overlay on a metal base

Abstract: A method and apparatus for welding an overlay on a metal base. The welding apparatus contains a supply of granular flux which feeds through a nozzle and covers the weld. An inert gas is introduced to the flux supply to purge it of air. The gas discharges through the nozzle and assists in protecting the weld. Particularly useful for welding an overlay of a nickel tantalum alloy.

Attachment pin for connecting insulation to ducts by resistance welding

Abstract: An attachment pin for attaching insulating batts to metal by a resistance welding method comprising a shank terminating at one end in a lathe-sharpened tip, the opposite end of the shank incorporating a head portion, the cross-sectional area of which head portion is at least about 25 times the cross-sectional area of the shank.

Welding by electron bombardment

Abstract: Electron beam welding apparatus wherein means are provided for welding a joint sealed by a sheet of foil and thereafter depositing a plastic product on the weld head to prevent contamination.

Device for electrical protective gas welding

Abstract: An electrical protective gas welding device for seam welding a plurality of layers together with different thickness wires mounts both the wire supply devices and the corresponding torches on the same electrical equipment housing for sequential operation thereof.

Thermionic insulated arc welding gun

Abstract: Improved means of insulating that portion of an air cooled arc welding gun which extends between the handle portion and the head portion to prevent thermionic emission dense enough to establish the conductance of welding current between it and the weldment, improved means for enclosing the welding current circuit suspended within the handle of the gun within a tube composed of insulating material to reduce the amount of heat radiated from the circuit within the handle, and improved means for suspending a highly heated welding current circuit within the handle to provide space between the wall of the handle bore and the suspended heated circuit for the circulation of cooling air therethrough. Also disclosed is the method of making the improved structure.

Resistance welding coated sheeting

Abstract: Welding current is fed, at least for one of the coated sheets, indirectly to the point to be welded by means of the sheet surface in order that an external layer remains intact and a contact established between the surfaces which have been uncovered for welding. Annular or linear edges and depressions are formed at the welding point in the sheet or on the intermediate welding pieces with the aid of stamps and/or cutting. Overcomes drawbacks encountered with conventional prior art welding machines where the outer layers of the welded sheets are destroyed by uncovering or by the fusion caused by the electrodes. Use: welding metal sheeting or elements coated with synthetic material, varnish or some other substance, such as steel, chrome-nickel steel, aluminium (anodised) or other metals.

Inert atmosphere tack welder

Abstract: This disclosure relates to spot resistance welding or tack welding of edge portions of sheet material, particularly the welding of seams of containers. Means are provided for effecting gaseous flow around each of a pair of opposed electrodes with the flowing gas being preferably an inert gas and the flow being selectively one of pressure to one electrode and vacuum or partial vacuum to the other or pressure flow to both electrodes. Inert gas flow between the sheet portions being welded is also obtained.

Resistance welding and soldering of coated - sheet metal

Abstract: A current is passed through the decoated welding point of the coated metal strip to be welded to the opposite pole of an electrode. The welding current passes from this metal strip to the second metal strip through decoated inner surfaces. Pressure is applied together with the welding current and the coated outer layer of the metal strip is unharmed.

Process for submerged arc welding

Abstract: A submerged arc-welding process performed on adjacent longitudinal edges of a pipe blank. Two submerged arc-welding units are supported on carriages which move on a stationary travel beam over the pipe blank. The welding units start welding at opposite ends of the longitudinal edges and weld toward each other until they meet. At that time one welding unit stops and returns while the second continues forward to overlap the welds while the fused flux remains electrically conductive at the area of overlap. After the second unit merges the welds, it returns.

Measurement and interpretation and application of parameters important to electron beam welding.

Abstract: A study of the electron beam welding process has been initiated by several AEC contracting agencies. The purpose of this study is to define the physical properties of materials and operational features of electron beam welding machines in order to better describe the characteristics of the electron beam welding process. The various agencies and organizations which have been involved in this study have used various kinds of welding equipment and diagnostic instrumentation. The Los Alamos Scientific Laboratory has been a contributor to this program in the areas of beam diagnostics and the relationship of physical properties of materials to the resultant welds. The welding machine which has been used for all of the studies described in this paper is a 7.5

Welding paste for resistance welding copper parts

Abstract: A WELDING PASTE FOR JOING COPPER PARTS BY RESISTANCE WELDING BY COATING SUCH PARTS TO BE JOINED AT THE POINTS PRIOR TO WELDING WITH THE PASTE CONTAINING A MIXTURE OF POWDERED SILVER OR POWDERED SILVER AND A SOLDERING FLUX.

Method and device for welding high tensile strength steel of higher strength

Abstract: At first to execute a welding of high tensile strength steel of more than 60 kg/mm2 an electro-slag welding technique is adapted.

Method of resistance welding using pulsed dc superimposed over steady state dc voltage

Abstract: Apparatus for welding, particularly resistance seam welding, wherein the voltage applied across the weld comprises a steady state direct current voltage having superimposed thereon an alternating current voltage or a chopped direct current voltage. This provides a true diffusion weld, results in a substantially uniform grain structure across the weld, and enables extremely high welding speeds.