Abstract: The seam welding apparatus includes a pair of rotating electrodes, an electrode supporting frame, a distance measuring means, and a controller. The electrode supporting frame supports the pair of rotating electrodes. The distance measuring means is provided on the electrode supporting frame and measures a distance to an edge of the steel plate. The controller controls the robot to adjust a running direction of the rotating electrodes so that a deviation comes into zero when a distance actually measured by the distance measuring means deviates from a predetermined distance. Thereby, it is accomplished that the seam welding apparatus is downsized as well as uninfluenced by the surface state and/or shape of workpiece (steel plate).

Abstract: Disclosed herein are some embodiments for safely charging a mobile system battery pack, even when the power source (e.g., adapter) voltage is at a relatively high level that would otherwise result in excessive charge current.

Abstract: If arc interruption occurs during AC arc welding, a first AC frequency predetermined for normal welding is switched to a second AC frequency higher than the first AC frequency. This allows the arc to be reignited without applying a high frequency high voltage, thereby preventing the damage of the surface of the weld bead or communication failure due to the high frequency high voltage.

Abstract: A process for cohesive bonding between a metal surface and a nonmetallic substrate is provided. The non-metallic substrate may comprise a plurality of microfilaments and/or nanofilaments dispersed into and below the surface of the substrate. The application of pressure and laterally-oriented high frequency and low amplitude vibration may allow for diffusion bonding between the metal surface and material of the nanofilaments. Another method includes discharging energy from a bank of capacitors to melt adjoining surfaces of the metal surface and nonmetallic substrate. Additionally, a cohesive bonding method may further comprise converting electrical oscillations of ultrasonic frequency into ultrasonic vibrations which are transmitted to the metal body and/or substrate for fusing the two materials together.

Abstract: An improved method of forming a bonded valve seat for a cylinder head wherein the configuration of the insert ring and cylinder head recess is such to ensure good bonding over the entire area and the proper amount of sinking of the insert ring into the cylinder head. The bonding process for the exhaust valve seats is different from that of the intake valve seats.

Abstract: A method of indirect spot welding two or more members together, comprising the steps of pressing electrodes against at least one of the members, flowing a square wave current between the electrodes and across the members during a first time period, pausing the flow of current, flowing a square wave current between the electrodes and across the members during a second time period, and stopping the flow of current.

Abstract: Method and circuitry is disclosed for controlling and stabilizing temperature of a resistance heat sealing element used in packaging operations. Temperature of the heat sealing element is measured by monitoring its resistance by means of a current sensing resistor placed in series with the heat sealing element. The resistivity of the heat sealing element is a function of temperature and current measurement, assuming substantially constant applied voltage, is an accurate measure of sealing element temperature. The circuitry reduces application of electric power to the sealing element in response to current in the sealing element dropping below a predetermined level. The circuit either continues application of electric power, or increases it, in response to the current being above the predetermined level. Circuitry is also provided for compensating for undesirable line voltage changes to maintain the heating element at a constant temperature.

Abstract: A precision electric welding device is used for welding dental crowns and bridges in the mouth. The dental elements to be welded comprise dentally suitable metals, especially titanium and titanium alloys. The device comprises a welding gun and a base unit provided with a direct current voltage source and a storage device for storing welding sequences. Each welding sequence defines the energy requirements for successive pulses in a particular welding operation. The base unit generates a series of controlled voltage potentials for each operation, and the welding gun is responsive thereto for performing the welding operations. The portable welding system is of the capacity-discharge, contact-resistance type, and performs welding with high-precision endo-oral metals by generating controlled sequences of electrical energy pulses (1) selected from a permanent storage library, or (2) manually controlled from a local console, or (3) externally controlled from an external computer.

Abstract: Methods and apparatus for fusing elements such as wires to one another. The elements to be fused are engaged in a notch or channel in one electrode, so that a first element, typically a stranded wire, contacts this electrode and also contacts the other element. A second electrode is engaged with the first element, and a fusing current is applied to the first element so that heat generated in the first element heats the second element as well. Where the second element is an insulated wire, heat from the first element vaporizes the insulation. The fusing current is applied as a series of low voltage, high current pulses.

Abstract: A precision electric welding device is used for welding dental crowns and bridges in the mouth, the dental elements to be welded being made up of dentally suitable metals, especially of titanium and titanium alloys. The device comprises, in combination, an electronic welding base unit supplied with direct current voltage source and provided with a storage device containing a plurality of welding sequences, each welding sequence defining the energy requirements for successive pulses in a particular welding operation. The base unit generates a series of controlled voltage potentials for each operation, and an interdental precision electric welding gun is responsive to said series of controlled voltage potentials for performing the welding operations.

Abstract: A power supply for a pulse type electrical resistance welder includes an A.C. source of electrical power, a firing circuit for delivering spikes of current to a pair of welding electrodes and a precharging circuit for precharging the firing circuit with a quantity of electrical energy sufficient to produce satisfactory welds in the first cycle or first few cycles of power. The precharging circuit is controlled by control circuit which includes a thumb wheel switch for presetting the voltage to which the firing circuit is to be precharged. A relay circuit automatically disconnects the precharging circuit from the firing circuit before the latter discharges its energy to the welding electrodes. A safety circuit is provided for automatically discharging the firing circuit in the event of a power failure.

Abstract: A monitoring and control system for use in conjunction with a pulse type welder which utilizes a computer to calculate the impedance characteristics of a weld and compare these characteristics to a preselected set of characteristics to determine if a quality weld has been made. The system then controls the heat and cool time to increase or decrease the tmeperature of the weld and thus control the size of the weld nugget. The monitoring control system is utilized in conjunction with a standard pulse welding control system, which standard system provides a series of heat impulses followed by a series of cool impulses, this cycle being repeated for a preselected number of cycles. The monitoring and control system senses the voltage and current in the welding load and feeds this data to a computer which, in turn, calculates the impedance of the weld.

Abstract: In an electrical resistance welder, whenever a material to be welded approaches the welding electrodes, a start signal is produced, so that welding current is supplied to the welding transformer in one direction for a certain period of time set by a time limit circuit, with the polarity changing in response to the start signal, whereby, even if materials are repeatedly fed for welding at high speed, they can be positively welded in a uniform manner.

Abstract: Apparatus for fabricating metal trusses having spaced preformed chord members of generally longitudinal predetermined length and cross-section joined by at least one preformed supporting web member of predetermined length and cross-section by electrically resistance welding together the chord and web member at a common region of contact with the chord member having a smaller cross-sectional area than the web member at the common region of contact. A device includes in to place a station for cleaning the chord and web members, means for moving the clean chord and web members to an assembly station for assembling the chord members in spaced relation joined by the web member. A device for passing the assembled truss along a support to the electrical resistance welder having opposed first and second electrodes of unequal resistance and adapted to releasably clamp the chord and web members respectively at the common region of contact.

Abstract: A strip (21) of pairs of terminals (13 and 14) are incrementally advanced into a bonding station (24) where electrical components, e.g., metallized film capacitors (10), are successively advanced adjacent to each pair of terminals. Each pair of terminals is bent into engagement with a pair of heat fusible end electrodes (11 and 12) on each electrical component. Sets of three welding pulses are respectively applied by a pair of welding devices (36 and 37) to each terminal. The welding pulses are monitored and if found to be below a predetermined magnitude, additional sets of welding pulses are applied to the electrodes. If a programmed control system ascertains that three successive welding attempts are unsatisfactory, or if five welding attempts are unsatisfactory in nine cycles of operation of the overall apparatus, further cyclic operation of the apparatus is interrupted. Facilities (38, 39 and 40) are provided to upset and reshape any metallic flash resulting from the welding operations.

Abstract: A machine or apparatus simultaneously manufactures a core-reinforced welded panel and assembles core strips in operative relationship with the face sheets of said panel. The machine includes a first welding head which is insertable in the space between the face sheets and has welding electrode means thereupon which internally weld securement portions of the core strips to adjacent inner surfaces of face sheets of any desired thickness.The welding head includes movable jaws mounting the welding electrodes to move the welding electrodes into engagement with the securement portions of the core strips and the welding electrodes are resilient to permit them to move independently of the movable jaws and each electrode provides an electrically isolated weld.A second welding head is provided which is capable of securing web portions of the core strips by weldments to one another after the weldment of the core strips at their securement portions has been accomplished by the first welding head.

Abstract: A resistance welding controller for dynamically controlling both weld current and weld time in order to achieve a desired .DELTA.R value. The resistance across the weld electrodes is monitored by the controller during the heat-up phase of the weld and compared to target values for minimum resistance (Rmin) and rate of resistance change (dR/dt). If the observed values for Rmim and dR/dt bear a predetermined relationship to the target values, a dynamic correction is made in the percentage heat control setting. The weld is then continued at the revised weld current level until the desired .DELTA.R value is satisfied. If upon weld termination, the observed weld time is greater than the target weld time, an additional correction in weld current is made in preparation for the next weld. In addition, the controller is also adapted to detect newly dressed weld electrodes and automatically respond by reverting to the original weld schedule.

Abstract: A control circuit for accurately controlling the duration of a welding operation.

Abstract: A phase controlled regulating circuit for a portable spot welder having an output transformer, utilizes a normally saturated transistor across one diagonal of a diode bridge circuit to interrupt the connection between the control voltage source and the regulating source, in response to a timer input.

Abstract: A method of, and apparatus for, respectively controlling the start of welding and the termination of welding during continuous resistance welding with the aid of an alternating-current at a roll-welding machine, wherein at least at one measuring station or location arranged ahead or upstream of the welding station or location and the workpiece to be welded passing through the measuring station there is determined the position as a function of time of the leading end as well as the trailing end of the workpiece to be welded with respect to the frequency and the phase of the welding current. By means of a computer processing the determined value there is accommodated to one another the speed of the workpiece to be welded and the frequency and phase of the welding current in such a manner that the first welding spot and the last welding spot are applied at an adjustable spacing from the leading end and the trailing end, respectively, of the workpiece to be welded.

Abstract: In combination with a resistance spot welding machine for welding superimposed electrically conductive members an improved apparatus for and method of cleaning welding electrodes and associated portions of the members to be welded are provided utilizing inert gas cooperating with electrical circuitry such that a sequential cleaning of each electrode and its portions are provided which is self starting and ending as a function of the presence of sufficient inert gas.

Abstract: A high speed seam welding system wherein single phase alternating current welding pulses are applied to electrode mechanism during only a less than maximum amplitude fractional portion of the wave form representing each successive current half cycle, and the current is substantially cut off between current applications to permit cooling. The relative seam welding movement of the electrode mechanism and the material to be seam welded is coordinated with the duration of the welding and cooling periods to more rapidly form a line of uniform weld nuggets. The system may also be operated at more conventional welding speeds to weld relatively heavy gauge materials.

Abstract: In combination with conventional apparatus for joining members of aluminum or other electrically conducting material by resistance welding, adjustable supports for arranging the work-contacting electrodes in spaced proximity to the work, and circuitry for inducing an inert gas shielded arc of alternating current across each electrode and the work, the apparatus being operable to effect self-cleaning of the electrodes as well as the work between successive welding operations.