Abstract: In the manufacture of spiral-welded steel pipe, material strip or plate is fed in its longitudinal direction and continuously formed into spiral pipe form. One side-edge of the strip and the other side-edge of the strip that has already been spirally formed are welded together by the electric-resistance method where they meet. The edges of the strip and formed pipe are held together simultaneously with or immediately after the electric-resistance welding from both inside and outside the pipe using a pair of pressure rolls. The bead formed as a result of the electric-resistance welding is reformed simultaneously with or immediately after the holding by the pressure rolls is accomplished. Then, the electric-resistance welded side-ends are welded again by the arc method.

Abstract: Device and method for welding nuclear fuel assembly structural elements, comprising a receiving stand for the guide tubes and structural elements of the assembly, and a welding group having a carriage movable parallel to the guide tubes comprising at least one welding gun united on the carriage by means enabling it to move parallel to a row of guide tubes and to rotate between an orientation in which the gun can pass between two adjacent rows of guide tubes and an orientation in which it comes to grip a tube at the location of the proposed weld, electrical welding pulses being applied to the guns.

Abstract: A process for producing an ERW tube having welds which have been improved in toughness without adversely affecting the toughness of the parent metal of the tube is disclosed. The process comprises forming a continuous low alloy steel strip into a tubular shape through a series of forming rolls, continuously carrying out electrical resistance welding of a seam which is formed from the opposite side edges of the hoop and which extends in the longitudinal direction to produce an electrical resistance welded tube, heating the welds of the thus obtained electrical seam welded tube to a temperature not lower than the A.sub.c3 point, then cooling the heated welds at cooling rate of 15.degree.-30.degree. C./sec for at least between 800.degree. C. and the A.sub.r1 point, and tempering the thus cooled welds of the tube at a temperature of 450.degree.-800.degree. C.

Abstract: Methods and apparatus for manufacturing tapered, hollow metal poles which can be used for manufacturing poles of various lengths, tapers and cross-sectional dimensions with the same apparatus. A substantially complete, tapered tube is formed from a plate or sheet of metal having lips at its longitudinal side edges which extend transversely to the major surface of the plate or sheet. The tube is guided at its lip portions to a weld point where pressure is applied to force the lips together by a grooved roller which applies pressure to the oppositely facing surfaces of the lips in directions transverse to such surfaces. The lips are spaced in advance of the weld point, and high frequency, electric heating current is supplied to the tube at opposite sides of the gap between the lips to heat the tube at the lips to welding temperature as it is advanced to the weld point.

Abstract: In a resistance welding apparatus of a detachable grip type an improvement consists in that each pipe grip has a bracket (16) whereon two double-arm levers (18), one per side member (3), are pivoted. Similar arms of each lever (18) are interconnected by an extension spring (19), while the other arms are operatively associated with swinging jaws (14) adapted to abut against the pipe surface in their operating position. Each side member (3) is provided with a stop (21) for limiting the movement of the levers (18) relative the corresponding side member (3) in the direction of the action of the extension spring (19).

Abstract: A method of manufacturing a solar panel element comprising a metal sheet or sheets secured to fluid-tight tubing substantially continuously along its length by metal which has been heated and cooled, e.g. weld metal, in which the tubing and the metal sheet or sheets are held in contact while they are heated to welding temperature, either forge welding or melting temperature. In the preferred methods, the heating is accomplished by high frequency, electric currents using a proximity conductor. Also, in the preferred methods, the tubing is formed with longitudinal lips as the heating is carried out, and the lips are secured together by welding them together simultaneously with the welding of the sheet or sheets to the tubing.

Abstract: Pipe components, i.e., pipes, adapting members and fittings made of weldable plastic, are interconnected by electrically weldable joints. The welding process is made possible by a welding sleeve 3 being connected to the output 4 of the device. A switch-on monitor 11 permits the switching on of a switch stage 7 of the welding current circuit. The thermal energy is determined by square-law simulation of the welding or mains voltage in a pulse generator 9, which produces a pulse frequency which is dependent on this value and whose pulses are summed in a counter 10. Once a count value that corresponds to the thermal energy has been reached, the switch stage 7 is switched off. If the count value is not reached a function monitor 5 gives a warning signal.

Abstract: This invention is made with a view to increasing the fusing strength of an end piece in a valve moving push rod for internal combustion engines. The fusing part of the push rod according to the present invention consists of an .alpha.-martensite structure and a primary truestite structure in a cotransition boundary range of a segmental section formed into the hardened layer of the end piece from the fused boundary surface of the end piece with a tube end part and is provided with a tough mixed layer arcuated from the inside end part of the above mentioned fused boundary surface to the outside end part thereof. This mixed layer is obtained by reducing by a heat feeding means a quick temperature drop caused by the fusing part simultaneously with cutting off the fusing current in welding by electric resistance the end piece on the fixed side surface to the peripheral edge of the end port of a tube material.

Abstract: A pipe resistance butt welding apparatus comprises a movable clamp and a fixed clamp to locate the pipes to be welded. Current-feeding shoes contact the ends of the pipes to be welded together. A device is provided for axially moving the movable clamp in fusing and upsetting the pipes. Both clamps and the device are mounted on an elongated supporting member. The shoes are carried by beams oriented along the supporting member and having bevels acted upon by drive rollers, whose axes are directed across the supporting member. The invention is useful for welding large diameter pipes.

Abstract: Markings are placed alongside the gap of a split tube and their distance is measured downstream from the point of welding; the measuring result is used to control upsetting pressure in the weld print.

Abstract: An axial mandrel having good electrical conductivity is fitted with conical metal washers and insulating pastilles in alternate sequence. A nut applied against an insulating support at the lower end of the mandrel exerts a compressive stress on the washers, the peripheral edges of which are applied against a lining sleeve placed within a leaky portion of a heat-exchanger tube. Each washer thus exerts a radial force which applies the sleeve in intimate contact with the tube along a number of circular lines corresponding to the number of washers. An electric current is passed through the mandrel, the washers, the lining sleeve, thus uniting the tube and the lining sleeve by means of circular resistance welds.

Abstract: Method and apparatus for welding a metal part, e.g. a tube or strip, to a thin, flexible metal strip using high frequency electric currents in which the part and strip are continuously advanced to a weld point where they are pressed together. In advance of the weld point, high frequency current is supplied to the part and the strip through contacts engaging them so that portions thereof are heated to welding temperature by the time they reach the weld point. From the point of engagement of the contact with the strip or strips to the weld point the strip material is maintained in a fixed path by a rigid member against which the strip is pressed by tensioning the strip with a pad frictionally engaging the strip. If desired, the current may be fed to the contact engaging the part through a proximity conductor to increase the heating of the part relative to the strip.

Abstract: A welded seam between overlapped edges of sheet material wherein the sheet material is heated to a temperature below the melting temperature and is forced together under high pressures to form a forged weld. The thickness of the sheet material in the weld area is reduced from double thickness to a thickness approaching a single thickness, with the weld interface being diagonally disposed. The weld is effected by grain growth across the interface such that the particular line along which the meeting surfaces of the metal are welded together is unobservable upon etching a cross section thereof and with magnification on the order of 100X. The heating is effected by applying to opposing edge portions which are to be overlapped and welded a high frequency current which effectively reduces heating to edge portions only of the metal with the heat effected area being in the vicinity of 0.1 inch.

Abstract: Tubes, rods, etc., are heated electrically in that current is applied via movable electrodes, one of which tracks the front and another one tracks the rear ends, but the electrodes remain spaced-apart during most of the heating.

Abstract: A tube mill which employs circular rotating electrodes for welding the edge seam along with means within the continuous tube for rolling the welded seam. An arm extends into the tube and carriers a rotating roller that contacts the seam just downstream from the point where welding occurs. A connector affixed to the arm extends upward through the region between the converging edges of the strip to a pivot pin. An air cylinder is arranged to rock the arm about the pivot pin and force the roller upward against the undersurface of the hot seam close to the circular welding electrodes to produce a smooth surface. The upper section of the arm carries a pair of rotatable discs of different thicknesses which guide the converging edges of the strip into proper position for welding. The arm carries a pipe which directs fluid past the roller to blow weld spatter downstream while simultaneously cooling the roller.

Abstract: In-line electrical welding apparatus for welding small diameter, thin-walled, metal tubing as it is advanced longitudinally comprising a high frequency electrical current source, a pair of upstream electrical contacts connected to one terminal of the source and a pair of downstream electrical contacts connected to the other terminal of the source through a proximity conductor which extends in close relation to the edges of the tubing to be heated from the downstream contacts to adjacent the upstream contacts. The contacts are each independently movable toward and away from the tubing along paths parallel to planes parallel to and intersecting the tubing axis and at an acute angle to each other. Guiding means adjacent to the downstream contacts apply welding pressure to the tubing, and further guiding means upstream of the downstream contacts but at least as close to the weld point as the upstream contacts guide the tubing as it is advanced.

Abstract: A large diameter rocket launch tube comprised of a pair of thin sheets wh are rolled and positioned in concentric relation with the seams disposed in spaced (180.degree.) relation. A pair of reinforcing weld strips are positioned inside the tube adjacent the seams, and a second pair of reinforcing strips are positioned inside the tube intermediate the first pair of strips. A bonding agent is spread on the inner tube and the tubes are assembled and spot welded prior to having the adhesive cured.

Abstract: A method is disclosed for welding one or more fins or longitudinally extended plate like members to tubes or pipes by means of radio frequency resistance heating. A V-gap necessary for the high frequency welding technique is created by deforming the tube to produce an out of round or ovular shape. The welding is accomplished as the out of round tube or pipe is deformed back to a round shape while at the same time bringing the fin or plate like member into contact with the tube or pipe.

Abstract: An internal spreader bar provides control of the convergence point and convergence angle of opposite electrically heated edges of a skelp during a tube seam welding operation and other controls are practiced to increase weld pressure at the faying surfaces.

Abstract: Methods and apparatus for manufacturing welded metal tubes of finite length in which an almost complete, axially split tube is advanced into a welding head where one edge face at one side of the split is accurately positioned and clamped and then the other edge face at the opposite side of the split is pressed against the one edge face. The welding head comprises a retractable edge face guide for said one edge face, clamping devices for holding and applying pressure to the tube, a proximity conductor over and extending along the abutting edge faces and contacts engagable with the opposite ends of the tube adjacent the abutting edge faces and connected to a high frequency current source for electrically heating the metal adjacent the edge faces to forge welding temperature.