Showing papers on "Electric resistance welding published in 1968"

Fundamentals, of explosive welding

Abstract: Summary An account is given of the basic mechanism of adhesion in all welding processes, and a brief review of fusion and pressure welding techniques is given. A completely new method of welding which employs high explosives is briefly described and explained in terms of the principle used in the hollow charge, which wm developed during days of war to defeat heavy armour plate. The results of experimmta carried out to find the mechanical properties of explosively welded joints are discussed and the application of the principle to the problem of welding tubes into end plates is described. Results of metallurgical examination of the welded joints are presented and discussed and the mechanism of the formation of the interfacial waves is briefly mentioned.

Multi-arc seam welding apparatus for thin metal sheet

Abstract: Apparatus for welding adjacent longitudinal edges of a thin flat workpiece being formed into a tubular configuration is disclosed as comprising a single welding head and an associated welding head bracket including pivot means and vertical adjustment means for selectively positioning the welding head above the moving workpiece. The single welding head includes three welding electrodes having their welding tips disposed in spaced linear arrangement in the direction of the moving workpiece, and being adapted to individually receive electric power for the generation of separate welding arcs. Associated with each of two of the three welding electrodes is a tilt adjustment means for individually adjusting the alignment of such two electrodes during welding operation so that the welding baths created by such two said welding electrodes overlap the welding bath created by the centrally positioned third electrode. The single welding head is configured to be closely disposed to the output side of a forming station for the thin flat workpiece so that the seam of the tubular configuration formed may be welded prior to seam separation due to material resilience.

Internal welding tool

Abstract: A welding head construction for use with typical traveling head automatic welding equipment to form submerged or shielded arc welds internally in confined spaces too small to receive the usual welding head of the equipment and where the welding operation and its progress cannot be observed visually. The internal welding head is provided with forming rolls which impart a curve to the weld wire or rod fed to the submerged weld-arc location. The internal welding head in order to enter a confined space extends parallel with and very close to the weld to be formed, and the weld rod and shielding material feed means likewise extend parallel to the weld to be formed. The curved forming of the weld rod enables the weld rod to be fed to the weld-arc location substantially perpendicularly.

Friction welding irregularly shaped objects

Abstract: Friction welding irregular-shaped workpieces by providing a minimal contact area on one of the workpieces and intentionally applying excess energy and pressure to the weld zone to produce excess flash material.

Electron-beam welding

Abstract: 1,152,224. Electron beam welding apparatus. VICKERS Ltd. 14 March, 1968 [15 May, 1967], No. 22507/67. Heading H1D. In electron beam welding apparatus with insulation 15 between the workpiece housing 1 and the whole of the gun structure including cathode assembly 5, anode 7, lens 8 and beam stop 9, a meter 11 is provided for measuring the welding current and connections 16 return intercepted electron current to the supply 10 without going through the meter. The aperture 4 of the housing is preferably circular with a radius not greater than one-tenth of the working distance D. With an accelerating voltage of 100-150 kV the radius of the aperture 4 may be 1 cm.

Mesh welding machine.

Abstract: The invention concerns a welding machine for electrically resistance welding together, to form a mesh, at their points of intersection in a mesh production plane, two crossed groups of parallel wires. The machine incorporates at least two pairs of opposed cooperating welding electrodes, one of said pairs being arranged on each side of the mesh production plane. A pair of transformers have their primary windings connected in series and each pair of said electrodes are connected to the secondary winding of one of the transformers in such a way that in operation the welding current will flow through the electrodes and through the secondary windings of the transformers in series.

Apparatus for welding thermoplastic synthetic foam blocks

Abstract: Apparatus for welding blocks or other molded forms of synthetic foam materials, such as, for example, thermoplastic polymers, including a welding device incorporating wedge-shaped separating means disposed in advance of a heating wire for traversing the desired location of the seam, whereby the heating wire is able to pass through the location of the seam substantially unobstructed by forces of friction and the like between the wire and the surfaces of the forms to be welded.

Method and apparatus for high speed welding of stainless steel tube

Abstract: APPARATUS FOR FORMING SEAM WELDED STAINLESS STEEL TUBE INCLUDING A SKELP FORMING MILL, DIES FOR FORMING THE SKELP INTO A TUBELIKE CONFIGURATION DEFINING A WELDING V BETWEEN ADVANCING EDGES OF THE SKELP, AN INDUCTION HEATER FOR PRODUCING CURRENT FLOW ALONG THE EDGES OF THE SKELP AND AROUND THE V TO HEAT PORTIONS OF THE SKELP DEFINING THE V, A NOZZLE DISPOSED ADJACENT THE V AND EFFECTIVE TO DIRECT AT A HIGH VELOCITY A MIXTURE OF INERT AND REDUCING GASSES ONTO THE V. AN INTERNALLY COOLED IMPEDER IS DISPOSED WITHIN THE SKELP ADJACENT THE V FOR RESTRICTING THE AREA OF THE CURRENT PATH TO MAXIMIZE THE HEATING EFFECT PRODUCED BY A GIVEN CURRENT FLOW.

Method of one-side arc welding and backing material therefor

Abstract: A method for welding steel plates and the like from one side, and a backing material therefor are provided which yields welds of exceptional quality, uniformity, and control. The weld backing material comprises a rigid channeled portion, containing an elastic mineral fiber composite in the channel, where the depth of the channel and the thickness of the fiber composite are determined by the following formula: WHERE D is the thickness of the composite, d is the depth of the channel, Rho c min. is the minimum compressed volumetric specific gravity of the composite, Rho i is the initial volumetric specific gravity of the composite, and m is the maximum misalignment of the plates to be welded. Welding is accomplished by compressing the backing material along the back of the joint to be welded and welding from the opposed side.

Feeding of wire in electrode welding processes

Abstract: 1,162,311. Welding by fusion. WELDING INSTITUTE. 5 Feb., 1968 [9 Feb., 1967], No. 6314/67. Heading B3R. In a wire feed device for feeding welding or filler wire 6 in consumable or non-consumable electrode arc welding processes respectively, variations in wire tension are substantially compensated, so that the wire is fed at a substantially constant rate, by the wire rising and falling in a wedge - shaped groove whereby the tractive effort applied to the wire varies corresponding to the fluctuations in tension, the groove being formed round the periphery of a rotatable body 10 of circular cross-section, the device further comprising one or more bodies 12 also of circular cross-section resiliently urged e.g. by compression spring 18, toward the body 10, a first guide means, e.g. a fixed pulley 14, having a peripheral groove, for aligning the wire with the groove at one end of an arc of the periphery, a second guide means 24 for leading the wire from between the bodies 10, 12 at the other end of the arc and means 20, e.g. a tension spring loaded pulley for tensioning the wire over the length of the arc. Wire is fed from a reel 16 having a friction hub 22 to the pulley 14, the peripheral groove of which is wedgeshaped and has a larger angle of acceptance, e.g. 90 degrees, than the groove in the body 10, the latter groove defining an angle of, e.g., 45 degrees. The bodies 12 have plain peripheral surfaces. Welding using a filler wire and microplasma torch is referred to.

Welding process for high-hardenability steel

Abstract: A PROCESS FOR TREATING A HIGH DUTY NOT READILY WELDABLE STEEL TO PROVIDE IT WITH A WELDABLE SURFACE. THE SURFACE IS FIRST BUTTERED WITH A WELDABLE COATING AND THEN THE BUTTERED LAYER IS HOT WORKED WHILE PLASTIC.

Method and means of joining copper parts by resistance welding

Abstract: A method and means for joining copper parts by resistance welding by coating such parts to be joined at the points prior to welding with a paste containing a mixture of powdered silver solder or powdered silver and a soldering flux.

Method for fitting semiconductor pellet on metal body

Abstract: A method for fitting a semiconductor pellet on a metal substrate, welding preliminarily a gold disc on the surface of a nickel plate by the electric resistance welding method and thereafter alloying a silicon pellet with said gold disc under the eutectic temperature of gold-nickel.

Method and apparatus for resistance welding

Abstract: 1,234,228. Welding by pressure. CONTINENTAL CAN CO. Inc. 1 Jan., 1969 [28 Feb., 1968], No. 136/69. Heading B3R. [Also in Division H2] In electrical resistance welding an alternating current is supplied to the electrodes in contact with the work, of such a frequency that the reactance of the welding current circuit including the electrodes and the work is higher than the resistance of the circuit. An apparatus for making metal blanks 11 into tubular cam bodies comprises a horn 12 and advance means 13 for moving the blanks 11 along the horn and an apparatus 14 for forming the blanks into tubular shape encircling the horn with overlapping edges. Roller electrodes 18, 24 are provided to contact between them the edges to be welded, although sliding or shoe electrodes may be used. The roller is mounted on a fluid piston/cylinder device 30, 31 so that the roller 24 is pressed tightly to sandwich the edges to be welded. Alternating current is supplied from a generator 35 including a step down transformer to the electrodes 18, 24 and a tack welder including electrodes 37, 38 may be provided to tack weld the overlapping edges prior to insertion between the electrodes 18, 24. The circuit from the generator to the edges to be welded includes the resistances of the rollers, of the connectionof the rollers to their leads (the constant resiss tances R) the resistances at the contacts of the rollers with the edges, of the edges and of the interface between the edges (the varying resistances RV) and includes the inherent self inductance of the circuit and the inductance or capacitance of an inductor or capacitor included in the circuit. In Fig. 5, the ohmic resistance of the circuit is presented by Rt=Rv+R and the ohmic reactance is represented by XL. The frequency of the generator 35 supplying sinusoidal or square wave current is selected so that the ohmic reactance XL is higher than the ohmic resistance Rv so that the varying resistance Rv has little effect on the current passing between the electrodes being determined by the impedance Z=#Rt 2 +XL 2 . It is stated that the edges may be butted instead of lapped and may be of separate sheets, also that the welding may be spot or butt welding.

Solid state heat control and initiating circuit for a resistance welder control

Abstract: A SOLID-STATE CONTROL FOR A RESISTANCE WELDER WHICH WILL APREVENT FALSE TRIPPING OF A SOLID-STATE LOGIC MEMORY IN RESPONSE TO BOUNCE OF THE CONTACTS OF AN INITIATING SWITCH WHICH INITIATES AND TERMINATES WELDING CURRENT FLOW AND A HEAT CONTROL CIRCUIT THAT WILL PROVIDE EQUAL OPPOSITE POLARITY HALF CYCLES OF WELDING CURRENT FLOW UNDER VARYING AMBIENT TEMPERATURE CONDITIONS.

Welding wire for the electric arc welding in air

Abstract: Welding electrode having an iron containing casing and a core containing calcium fluoride, titanium dioxide and potash feldspar.

Hermetically sealed electrolytic device

Abstract: A method is described for forming a hermetic seal on a wet electrolytic device having a metal container and a metal closure member, and containing a liquid electrolyte. The method comprises placing the closure member in sealing position with respect to the container to form a seam between them, and electric resistance welding the container and the closure member together at a series of positions along the seam. During the welding operation at each welding position, the closure member and the container are pressed together at the portion of the seam being welded and that portion is bathed in a fluid, preferably the electrolyte used in the device, to provide uniform electrical conditions to the weld area. Typically, the container and closure member are made of tantalum. Also disclosed is a hermetically sealed electrolytic device of the type described above which is reduced in internal pressure at room temperature to permit the liquid electrolyte to expand upon heating of the device with less pressure buildup.

Direct current welding system having minimum inductance

Abstract: An electrical resistance direct current welding system is disclosed including circuitry providing low inductance and having switching means connected adjacent the welding electrodes whereby the current flow to the electrodes may be interrupted with no damaging arc resulting

Copper welding process

Abstract: 1,219,235. Welding by fusion. E. I. DU PONT DE NEMOURS & CO. 5 March, 1969 [29 May, 1968], No. 11807/69. Heading B3R. In TIG-welding of copper, welds free from oxide occlusions, objectionable porosity and lack of ductility are obtained by providing around the outside of the entire, or at least the leading edge of, the usual shield of inert gas (e.g. helium, argon or mixtures) a further, non- inflammable gaseous shield comprising a mixture of non-oxidizing, non-combustible gas (e.g. nitrogen, helium or argon) and a gaseous reducing agent (preferably at least 5% of the mixture) selected from hydrocarbons with up to 4 carbon atoms and methanol, ethanol and isopropanol vapours. As shown, nitrogen containing and preferably saturated with, methanol (or ethanol) vapour is supplied to a chamber 8 surrounding an inner nozzle 3 through which inert gas providing the usual arc-surrounding shield is directed. The gas in the chamber 8 is directed through a continuous narrow opening or one or more slots or, as shown, orifices 11 in the chamber wall 10 to provide the further shield. Additional copper may be supplied by a copper filler wire or rod 6. In Fig. 3 (not shown) nitrogen, from a tank (13) is taken through a body of methanol (16). In an example of butt welding, with filler rod, electrolytic copper plates are bevelled (at 38-45 degrees) and clamped in position with a copper backing strip. When welded on one side, the workpiece is turned over, the root chipped out, and the final weld effected.