Abstract: Method and apparatus for detecting whether or not the gap in adjoining ends of a ring-like workpiece to be flash welded is of normal size, or is so much larger as to produce an unsatisfactory weld. The invention provides means whereby the amount the movable platen of a flash welder moves in a direction toward the stationary platen is compared with its position when the ends abut and flashing begins. If the ends are not materially beyond a predetermined normal gap, the welding action proceeds; however, if the ends are spaced beyond such normal gap, further action of the flash welding process is aborted, or a signal is activated; or both abortion and signal are provided. The invention is especially adapted for use in welding rings which are formed and welded in high production, such as rings that are further processed to make rims for tires of a vehicle.

Abstract: Work pieces to be joined together by the flash butt welding method are brought together at a preset no-load voltage, the end faces of the work pieces are fused, and an upsetting is accomplished. The amount of the upsetting is determined within from 1.2 to 3.0 of the amount of the maximum gap between the end faces of the work pieces being welded together, which gap forms in the course of fusing the end faces of the work pieces. The maximum gap is determined from the following relation:.DELTA..sub.max =f(U.sub.o,.delta.),where:.DELTA..sub.max =maximum gap;U.sub.o =no-load voltage;.delta.=thickness of the work pieces being welded together.Empirical formulas to determine the maximum gap for work pieces of various thicknesses are presented.

Abstract: In a flash welding apparatus, different length guides and driving devices thereof are formed on lower parts of an inlet side electrode table and an outlet side electrode table and the electrode tables and a compact rotary shear unit are arranged in the direction perpendicular to a strip line when both of the electrode tables are approached and one of the guides is commonly used as a guide for shifting a flash trimmer lower unit and a guide is formed on one of the upper electrode frames of the electrode tables so as to shift a flash trimmer upper unit and the rotary shear unit of the inlet side electrode table and the rotary shear unit of the outlet side electrode table and a pair of the upper and lower trimmer units are aligned in the plan view.

Abstract: A rectangular waveform voltage is applied between electrodes for welding by using a variable voltage-variable frequency type inverter as the power source for welding whereby the local short-circuit between workpieces can be immediately changed to the flash whereby the fine flash can be continuously generated to remarkably improve the quality of the welded part, and the voltage control can be attained without changing the voltage waveform.

Abstract: In arc butt welding the arc is moved between the faces of the parts to be joined by a magnetic field. In order to insure the arc travels over the whole of the faces to be welded the parts are moved generally parallel to the faces so that the overlapping area of the faces changes during the arc heating.

Abstract: A welder arranged inside pipes to be welded comprises a housing with the longitudinal axis thereof matched with the axis of the pipes. On the housing are a welding transformer and two mechanisms clamping the pipes, each having a drive moving the mechanism along the axis of the housing, and each being electrically connected to the transformer. The housing has mounted thereon a pipe flashing and upsetting mechanism with its own hydraulic drive, kinematically coupled to one of the pipe clamping mechanisms, a hydraulic pump supplying fluid to the drives, and a mechanism driving the welder along the pipes' axis. The housing carries two bearing discs secured at opposite ends and three clips mounted on roller supports and movable along the housing's axis. Two clips are incorporated in the first and second clamping mechanisms, respectively, and the third is part of the flashing and upsetting mechanism.

Abstract: A mobile rail welding machine comprises a frame, two undercarriages supporting the frame, a hydraulically driven flash butt welding unit for welding abutting rail section ends of a track rail mounted on the frame intermediate the undercarriages, a hydraulically driven weld burr removal unit mounted on the frame intermediate the undercarriages, which units may be integrated with each other, and a hydraulic jack for the frame operable to relieve the track rails of the machine weight.

Abstract: A mobile rail welding machine comprises a frame, a hydraulically driven flash butt welding device, a "Thermit" welding unit and preferably an electric arc welding device mounted on the frame for selectively flash butt welding, "Thermit" welding or arc welding abutting rail section ends of a track rail, and a weld burr removal device adjustably mounted on the frame for selectively removing weld burrs at either rail.

Abstract: A device for controlling a butt welding machine includes a pressure equalizing hydraulic slide valve connected to a manifold between the rod space of a clamping hydraulic cylinder and a reversible hydraulic slide valve coupled to both the delivery and drain manifolds of a hydraulic fluid supply system. Upon upsetting, the rod space communicates through the pressure equalizing hydraulic slide valve with the drain manifold, providing the same pressure above and beneath the piston and releasing a part of the clamping force. Provision is made for a programmed control unit or timer for energizing electromagnets adapted for switching the pressure equalizing hydraulic slide valve and a follow-up or tracking slide valve of a hydraulic drive adapted for carrying welded parts.

Abstract: In a flash welder, instead of using a flexible conductor, the electrical connection to the moveable electrode table is made by a connecting conductor which is slidably connected both to the moveable electrode table and the secondary of the welding transformer. The connecting conductor is mounted on the moveable electrode table in such a manner that, during non-welding periods, it may be retracted within the moveable table, disconnecting it from the transformer and thereby clearing the space between the electrode tables for other workpiece machining operations.

Abstract: The invention relates to a device for welding workpieces that have a large cross-sectional area, as well as for cases of high welding power requirements. The device in accordance with the invention comprises a mechanism for continuously displacing the workpieces being welded with a controlled drive, a mechanism for imparting to the workpieces additional reciprocating motion, a welding transformer, and a means for controlling the speed of the drive. The drive speed control means includes a welding-current pulse shaper coupled to the output of a current transformer, the latter being included in the primary circuit of the welding transformer and a welding-current pulse-length setter. The latter and the output of the pulse shaper are coupled to a comparator, the output whereof is coupled to the drive control circuit.

Abstract: A flash and upset material formed in a flash welding operation can be removed by a machining of the flash and upset material for a short time after the welding operation by providing a workpiece clamping function by a main clamp and providing a welding current feeding function by an electrode table. The main clamp is heavy whereas the electrode table is light so as to be easily movable, whereby the electrode table in the light weight can be backwardly shifted for a short time after the welding operation and a space for inserting a tool holder equipping with a tool for machining a flash and upset material, is formed near the welded line. Since the flash and upset material can be machined during the time maintaining the softness of the flash and upset material at relatively high temperature for a short time, the machining can be attained by only pair of tools.

Abstract: According to the invention, the continuous flash butt-welding machine supplied with power from a mobile diesel-generator power plant comprises a rectifier-charger the input of which is connected to the diesel-generator. The machine has a storage battery provided with a charge-discharge sensing element connected to the rectifier-charger. The machine also has an inverter with a unit for controlling the frequency and amplitude of the voltage at the inverter output. The inverter is connected to welding transformers and to a current transducer. The control unit is connected to the charge-discharge sensing element, the current transducer and a flashing value sensing element. The proposed invention makes it possible to reduce the installed power of the diesel-electric units of mobile power plants and to increase the life of the diesel engines and the thermal efficiency of the welding process.

Abstract: A strip flash welder having a guillotine shear unit which is movable from a position out of the strip flow path into a position for shearing strip ends between the main clamping dies of the machine.

Abstract: A welding machine auxiliary transfer clamp for pushing the end of a coil against a spacer bar and including a pair of clamping elements, each including a cylindrical ram operated by fluid cylinder, there being a ball connection intermediate each fluid cylinder and its respective ram to enable the upper and lower rams to pivot freely about their longitudinal axis so as to prevent occurrence of a gap otherwise formed by lateral tilting of the coil, whose end is to be welded.

Abstract: Improved apparatus and method for performing flash welding is disclosed. The apparatus moves adjacent surfaces of workpieces toward each other and applies electrical energy between them for flash heating the surfaces in a flashing step, after which it forces the surfaces together in an upsetting step, while continuing the application of the electrical energy for a predetermined time. Apparatus is provided for monitoring the amount of electrical energy applied to the workpieces during welding, along with control circuitry, for calculating and limiting the amount of electrical energy applied during the upset step to a predetermined function of that applied during the flashing step. An energy recorder produces an indication of the amount of electrical energy applied to the workpieces during welding.

Abstract: The present invention discloses a full-automatic flash welding apparatus wherein the trailing edge of the preceding strip and the leading edge of the succeeding strip are automatically accurately positioned, rigidly clamped and simultaneously cut off, the new trailing and leading edges are automatically machined and then butt welded, and thereafter the flash on the upper and lower surfaces of the joined strips is automatically removed.

Abstract: Means for monitoring the energy used in flash welding operations wherein two signals are simultaneously fed to the input of a multiplier, one signal being substantially proportional to the welding current, and the other being substantially proportional to the welder transformer secondary voltage applied to the work. The output of the multiplier is fed to an integrating amplifier circuit and the output of the latter is fed to a level detector amplifier. Voltage changing means is used to change the sensing level of the level detector amplifier to in turn affect operation of indicating means to indicate the sensed level.

Abstract: A welding apparatus employing a self-contained pumping accumulator plant hydraulically associated with a hydraulic ram of a moving clamp transfer gear for gripping pipes being welded. The apparatus employs a device for decreasing the pressure in the hydraulic ram and in a pilot valve during flashing and for increasing pressure during upsetting. The apparatus also employs a a low-pressure high-capacity pump with a filter, a relief valve, a nonreturn valve and an unloading slide valve, two high-pressure low-capacity pumps and a device for cutting the pumps and the unloading slide valve in and out. The pumping accumulator plant and the high-pressure pumps communicate with a main oil plant; a hydraulic control of the slide valves of the clamp hydraulic drives is connected to the pumping accumulator plant. The pilot valve is controlled by a welding process program control actuator.

Abstract: A method for controlling flashing speed during resistance butt welding comprises measuring values of current density for at least two joints between parts being welded, converting them into d-c. voltages, detecting a maximum voltage value, comparing it to a preset d-c. voltage, the resultant difference value being used as flashing speed control parameter. An apparatus for carrying out the method comprises electric circuits whose number is equal to the number of joints being welded. Each circuit comprises a welding transformer and a circuit for conversion of flashing current density into d-c. voltage. A maximum signal detector comprises circuits for conversion of current density into d-c. voltages, whose number is equal to the number of joints being welded. The detector output is connected to the circuit for comparing a current voltage value to the preset one.

Abstract: A corona discharge wire made of electrically conducting wire of high tensile strength to which is connected a metallic fixing element on both sides of the discharge portion. The element forms a fused mass disposed in a zone surrounding the wire and solidified around it. The fixing element may consist of two parallel pieces of wire interconnected by an annular extension.

Abstract: A method and apparatus for monitoring parameters which control the quality of welds made by the rotating arc method. Total electrical energy delivered to the parts being welded is controlled and its analog divided by the time during which this energy was applied to obtain average rate of energy delivered. Total mechanical work done on parts being welded and the mechanical relative displacement of machine platens is measured and work analog is divided electronically by the displacement analog to determine average mechanical work per unit of displacement. The two averages thus obtained are compared to preset levels of average electrical energy and mechanical work which have been established empirically. Indicators warn the operator of any variation from the norm. Separate indications and comparisons are also made of each of the parameters.

Abstract: A flash welding machine which comprises two pairs of current-carrying welding electrodes, one pair movable and the other, stationary. A double cut guillotine shear is normally positioned forwardly and alongside the welder at a "stand-by" position, remote from the welding position to avoid splattering from welding sparks. When it is desired to shear and weld, carriage means move the shear longitudinally alongside the machine and then laterally into a gap formed by moving the movable pair of welding electrodes from the stationary pair. Depending upon the selected gauge bar of a ladder-like gauge bar construction mounted on each side of the shear when in the "stand-by" position, such selected gauge bars are clamped between the lower current-carrying dies and the lower blades of the shear so as to provide back-up support for such blades as well as to tightly clamp the selected gauge bars for accurate gauging of the projection of strip desired beyond the welding dies after shearing.

Abstract: Apparatus for welding parts, such as pipes, end to end by means of an electric arc which is caused to rotate along the adjacent edges of the pipes. Two separate magnetic fields are used to cause the arc to follow a spiral path along the edges so that pipes having a wall thickness greater than one quarter of an inch may be welded.

Abstract: A combined thermal welding and cold upsetting method for interjoining opposing ends of stranded wire conductor cables in which the individual strands of each cable end are first metallurgically bonded to an intervening solid metal junction member which is then mechanically upset, cold worked and partially removed to provide a relatively thin joint or interface section of solid metal extending between and interjoining the multiple cable strands; the junction section having the circumferential configuration and cross-sectional area of the parent cables and selectively regulated strength properties.