Abstract: A system and method of determining the quality of a spot weld based on a set of image data includes separating the weld data from the background data and estimating a diameter of a weld (e.g., the nugget diameter of a spot weld) based on the weld data. The image data (e.g., a digital image) represents an image of the weld and includes weld data and background data. The estimation indicates the quality of the weld. In one embodiment, the surface brightness of the image data attributable to the spot weld is used to estimate the inner diameter of the spot weld.

Abstract: An inter-welding electrode moving amount detecting method includes the below steps: moving a driving section of electrode driving means having the driving section connected to at least one of a pair of electrodes provided to a welding gun; detecting an inter-welding electrode moving amount due to expansion/contraction of a nugget when a member to be welded is pressed, electrified and welded by the pair of electrodes; and obtaining the inter-welding electrode moving amounts by adding a moving amount of the driving section to an electrode moving direction due to the expansion/contraction of the nugget during welding and a deflection (alternatively, a strain amount) of the welding gun due to a pressing force.

Abstract: A welding electrode with a configuration (2) for the ultrasound introduction for the testing of weld joints, in particular resistance welded joints, comprises an ultrasound transmitter for the impingement of the welding region with ultrasonic waves and an ultrasound receiver disposed at a spacing from the welding region, for the reception of the ultrasonic waves passed through the welding region. To provide a welding electrode which is simple in structure, which is suitable for an impingement of the welding region with longitudinal ultrasonic waves, the ultrasound transmitter radiates the ultrasonic waves axially into the welding electrode (4) or axially or obliquely into a channel (42) of the welding electrode which is filled with a medium transmitting sound.

Abstract: Methods and apparatus are provided for monitoring resistance spot welding process conditions in real time by using welding data in an energy balance model in integral form to estimate the mean weld temperature and to predict process conditions such as occurrence of splash, and weld diameter. Using predicted welding process conditions, welding parameters are modified in real time to prevent splash and produce sound welds.

Abstract: This invention relates to methods to control the resistance spotwelding process using an electric servomotor actuator to move the welding electrodes to the work and apply force to them. Measurements of actuator position, servomotor drive voltage, servomotor drive current, voltage across the welding electrodes, welding transformer primary current, welding transformer secondary current and power factor in the primary circuit of the welding transformer are used separately and in combination to determine various conditions such as identify defects in the welding machine, the electric cabling, the welding process and in the weld itself. Depending upon the defect found, the welding parameters are changed to overcome the defect, and/or the need for an additional weld is indicated and/or an error indication is generated.

Abstract: The present invention discloses an apparatus and a method for monitoring the quality of a spot welding process. The measured electric current and voltage signals between electrodes of a spot welding system are converted into digital data first. Then the two digital data are processed to obtain their complex forms via Hillbert transform respectively to construct their imaginary part. Finally, the electrical impedance Zin is obtained from dividing the complex form of digital voltage by the complex form of digital current. The electrical impedance Zin can be applied to compare with historical data to diagnose the quality of spot-welding points.

Abstract: An intelligent welding gun is provided with a fixed side sensor in a fixed side portion. The mechanical impedance of the fixed side portion is kept small, which permits the mechanical impedance to be set in a range where the fixed side sensor can effectively detect at least one of a position of a fixed side welding tip and a pressing force imposed on the fixed side welding tip. The fixed side sensor and a moving side sensor constitute a redundant sensor measurement system. Various kinds of methods conducted using the above welding gun include a method of calibrating a sensor (including calibration of a reference point and a gain), a control method of suppressing a welding expulsion, a re-welding feedback control method, a control method of a welding strength, a control method of reducing a clearance between workpieces, a method of correcting a welding robot track, and a method of managing a positional accuracy change at a welding point.

Abstract: In an automated welding machine, where a flow of liquid coolant is supplied to welding components on the machine from a source of coolant and then returned to the source of coolant, a safety system is provided that shuts down the flow of coolant in the event of a fault. Faults are detected by a supply sensor and a return sensor for measuring the flow rates of coolant in the supply and return lines. A microprocessor is adapted to compare the supply flow rate and return flow rate and detect differences between the two rates. The difference between the detected rates as compared to a leak threshold value, and the microprocessor is adapted to generate a valve shutoff signal in the event the detected difference in flow rates exceeds the leak threshold value. A value in the supply coolant line is responsive to the valve shutoff signal to shutoff flow of coolant in response thereto.

Abstract: The present invention provides an electrode assembly for a spot welder which has an acoustic sensor built therein. In a preferred embodiment of the present invention, a spot welder has a first and second electrode assembly according to the present invention. During welding, the acoustic sensor from the first electrode assembly selectively generates a burst of acoustic energy which passes through a weld subject and is received by the second electrode assembly. The acoustic sensor in the second transducer then emits an output signal, representative of the geometry of the weld nugget, to a computer.

Abstract: This invention concerns weld quality measurement. In particular it concerns an apparatus and a process for measuring on-line, while the welding process is under way, the quality of the resulting weldment. The invention is applicable to spray-transfer gas-metal arc welding, short-circuiting transfer gas-metal arc welding, pulse welding, radio-frequency resistance welding and submerged arc welding. It involves the measurement of voltage or current and the generation of an artificial signal for the other. A two dimensional signal analysis then produces data for comparison with data obtained from a high quality weld.

Abstract: A device for predictively diagnosing the prevailing quality of the technical work result of a technical installation, in particular, the prevailing quality of the welding spots of a welding robot. The device includes a device for cyclically acquiring sets of measured values, whose values influence the desired quality of the work result of the system ,an installation model which uses sets of measured values of the installation to simulate an actual value for the prevailing quality of the work result of the installation, and a device at least for parameterizing the installation model. The parameterizing device includes a data base for storing selected sets of measured values and associated characteristic values, which are a measure for the quality of the work result of the installation, and the device generating and/or optimizing at least the parameters of the installation model by successively evaluating the sets of measured values and the associated characteristic quality values by an iterative optimization.

Abstract: An inter-welding electrode moving amount detecting method includes the below steps: moving a driving section of electrode driving means having the driving section connected to at least one of a pair of electrodes provided to a welding gun; detecting an inter-welding electrode moving amount due to expansion/contraction of a nugget when a member to be welded is pressed, electrified and welded by the pair of electrodes; and obtaining the Inter-welding electrode moving amounts by adding a moving amount of the driving section to an electrode moving direction due to the expansion/ contraction of the nugget during welding and a deflection (alternatively, a strain amount) of the welding gun due to a pressing force.

Abstract: A method and apparatus for measuring the contact resistance at electrode-to-workpiece and workpiece-to-workpiece interfaces for spot welding simulations. A constant compressive load is applied through electrodes and workpieces to simulate a load applied during an actual resistance spot welding process. A discharging current circuit applies an initial high current of the order of 1.2 KA to electrodes and workpieces to break down contaminant films on surfaces of the workpieces. A relatively small constant current of about 2A is then applied to the electrodes and workpieces and the voltage across and the current flow through the electrodes and workpieces are measured. The contact resistance is determined from the measured voltage and current.

Abstract: A plate-shaped jig (9) is fixed between a fixed-side electrode (5) and a moving-side electrode (6). The end of an arm is set to move by an external force in the direction the moving-side electrode (6) moves, and then the moving-side electrode (6) is moved toward the jig (9) and pressed against the jig (9) by such a force that the end of the arm is pushed up by a counterforce, the position of a robot in a tool coordinates system and the position of a gun-axis servomotor (7) are acquired as reference positions when the jig (9) is held between the moving-side electrode (6) and the fixed-side electrode (5) to release the holding of the fixed jig (9) with pressure. Thereafter, similarly , the position of the robot and the position of the gun-axis servomotor (7) are acquired to calculate the wear amount of the fixed-side electrode (5) and the moving-side electrode (6) from the respective differences from the reference positions.

Abstract: Resistance welds on overlapped sheets of metal, such as the welded side seam of 3 piece cans, are monitored by measuring the width of the extrusion (5, 6) formed by material flowing out from the edge of the overlapped sheets (1, 2) caused by the welding process. The width of the extrusion (5, 6) is interpreted in terms of the temperature of the weld, and the welding process can be adjusted accordingly. The measurement of the extrusion width can be done optically.

Abstract: The invention concerns a welding device control method and a novel welding device for the electrical spot or resistance welding of material to be welded. The welding device comprises at least two weld electrodes which, for the welding process, are pressed by an actuating device at a predetermined electrode force against the material to be welded. The welding device further comprises a control system which controls the welding current via a controller.

Abstract: In a resistance spot welder in which an operation of pressurizing an electrode is conducted by an electric servo motor, an amount of thermal expansion due to production of a weld nugget is detected every moment by reading an encoder which is incorporated in the servo motor. When the detected amount of thermal expansion reaches a preset reference value, it is judged that the weld nugget attains a predetermined strength, thereby stopping a current supply. According to this configuration, a predetermined amount of input heat is ensured, so that an excellent welding quality is surely obtained.

Abstract: A system and method for monitoring compression pressure, temperature, and alignment of first and second electrodes of a robotic welder. An apparatus is provided with hingedly connected, spaced apart top and bottom plates. An aperture is disposed in the top plate for receiving the first electrode therein and an aperture is disposed in the bottom plate for receiving the second electrode therein. Temperature sensors are mounted adjacent to the top and bottom plates for sensing temperature of the electrodes. A load cell is included in the apparatus for sensing pressure between the electrodes as well as a limit switch for indirectly sensing misalignment between the electrodes. A data processing unit is in electrical communication with the temperature sensors, load cell, and limit switch for performing software analysis.

Abstract: Apparatus (2) for measuring the quality of spot welds, comprising a housing (4); a fluid medium (6) in the housing (4); transmitter means (8) for transmitting at least one ultrasonic pulse through the fluid medium (6) to a spot weld (10), the ultrasonic pulse then reverberating in the spot weld (10); and receiver means (16) through which the ultrasonic pulse passes on its way to the spot weld (10), the receiver means (16) being ultrasonically sensitive so that it is able to receive echoes from the spot weld (10) by the reverberation of the ultrasonic pulse in the spot weld (10), the receiver means (16) comprising a plurality of ultrasonically sensitive elements (18), and the receiver means (16) being such that during use of the apparatus (2) the receiver means (16) is located adjacent the spot weld (10).

Abstract: An inspection system for a welding apparatus for performing welding by supplying electric power outputted by an inverter based on a command from a welding control unit, through a welding transformer to a welding gun. The inspection system includes a first input/output section for receiving positive and negative components of a waveform outputted by the inverter and for outputting waveforms, a second input/output section for receiving waveforms outputted by the welding control unit and for outputting waveforms similar to those outputted by the inverter. A selector selects the operation of either the first or second input/output sections. A first OR circuit has applied thereto the first waveforms outputted by the first and second input/output sections, and a second OR circuit has applied thereto the second waveforms outputted by the first and second input/output sections. A third OR circuit has the outputs of the first and second OR circuits applied to the inputs thereof.

Abstract: A welding spot is held between electrodes either biased with a controlled pressure, having a controlled voltage applied thereacross, and variations of an inter-electrode distance are detected for a welding quality control, in which the distance variations are time-integrated, a nugget size is estimated on a basis of the integration, and a decision is made of a conformity of welding quality based on an estimated nugget size.

Abstract: A welding system for real-time weld quality detection during resistance welding of a workpiece has a sensor assembly including a winding and a core mounted generally coaxially within the cylinder of the welding gun. A piston and piston rod assembly are mounted for coaxial movement within the cylinder. The piston rod has an end protruding from the cylinder for affixing an electrode thereto. Axial movement of the piston rod relative to the cylinder causes axial movement of the core relative to the winding to vary a length of core and winding overlap. The sensor assembly produces an output signal based on the length of core and winding overlap to indicate piston rod position relative to the cylinder. Weld control logic receiving the sensor assembly output controls welding of the workpiece in real-time.

Abstract: A current sensor 20 in the form of a coil such as a toroidal coil provides as its output a current sense signal TS representative of a differential waveform of a welding current I. In a waveform restoring unit 22, integrating circuits 30 and 32 are switchable between an enable state (first state) and a reset state (second state). In the enable state, the current sense signal TS from the current sensor 20 is integrated and issued as integration value signals AIa and AIb representative of a waveform of the welding current I, whereas in the reset state, the integration value signals AIa and AIb are reset to reference values (e.g., 0 volt). A switching circuit 34 detects timings of each cycle or each half-cycle of the welding current I on the basis of a waveform of the current sense signal TS, and alternately switches the states of the integrating circuits 30 and 32 in a complementary manner and at a predetermined timing so that while one is placed in the enable state, the other is in the reset state.

Abstract: A resistance welding method in which a welding current is passed through a welding portion of a material to be welded in a condition that the welding portion is put in between a pair of electrodes, so that the welding portion is fused and welded by use of the resistance heating caused by conduction of the welding current under pressure applied between the pair of electrodes, characterized by comprising the steps of: measuring a welding width of the welding portion by the width measurement unit; calculating a reference welding height of the welding portion from the measured welding width on the basis of a predetermined reference welding sectional area of the welding portion; passing the welding current through the welding portion until the height of the welding portion reaches the calculated reference welding height; and displaying current-conduction time from the start to end of conduction of the welding current on the display unit.

Abstract: The invention is a method of forming and evaluating a weld (52). In an initial step, first and second welding electrodes (56, 60) are placed against corresponding first and second contact surface areas (57, 61) on a pair of adjoining metal parts (44, 40). A welding level of electric current is directed between the electrodes (56, 60) to form an electrical resistance weld (52) between the metal parts (44, 40). The first electrode (56) is then removed from the first contact surface area (57). A subsequent step includes sensing surface temperatures at the first contact surface area (57) by sensing infrared radiation emitted from the first contact surface area (57) under the influence of heat previously generated resistively by the welding level of electric current. The resistance weld (52) is evaluated by comparing the sensed surface temperatures with specified surface temperatures corresponding to specified weld conditions.

Abstract: Before a deterioration of a secondary current sensor is detected, a controller effects a feedback control process based on a secondary current from the secondary winding of a welding transformer which is energized by an inverter, for thereby controlling a welding current with a high degree of accuracy, e.g., an accuracy level of .+-.1%. At the same time, it is monitored whether a detected value of a primary current from the primary winding of the welding transformer, which is detected by a primary current sensor, exceeds a predetermined allowable range with respect to a reference value of the primary current. If the detected value of the primary current exceeds the predetermined allowable range, then it is decided that the secondary current sensor is deteriorated.

Abstract: A method and product of making a motor armature that includes a carbon disk or carbon barrel commutator subassembly with the carbon layer soldered to the metal commutators. The novel method includes, while fusing the armature wire segment to each metal commutator, applying cooling liquid to the commutator segment being fused and/or the fusing electrode in order to remove or reduce heat transfer to the solder layer. This technique yields many benefits to the process and product, including (1) overheating, flow, and beading of the solder is avoided, (2) temperature rise of the electrode and fused joint can be better controlled, (3) application of power and power consumption can be more uniformly achieved, and (4) better repeatability, yield, and quality of product can be achieved.

Abstract: A weld controller is coupled to a communications network which has an operator interface unit for monitoring and controlling the weld controller and other weld controllers on the network. A time of day clock provides a chronological reference to tag weld current and voltage data and other data when it occurs for storage in its memory which is also accessible by the operator interface unit for storing in said system database. A memo pad in the weld controller is also accessible to the network for storing data for diagnostic purposes, said data including faults, events, and other operational data. The data can then be displayed, edited, and stored by the operator interface's program.

Abstract: The present invention provides a method and apparatus to control and verify weld-quality in a homopolar pulsed weld by measuring in-process parameters. Methods are disclosed for real-time weld-quality control in a weld-quality control system for homopolar pulsed welding, including measuring at least one in-process parameters that correlates to a resulting weld-quality of a weld. Further, methods are disclosed for post-process weld-quality verification for homopolar pulsed welding, including identifying at least one in-process parameter that may be used as a post-process weld-quality verification parameter and utilizing such a post-process weld-quality verification parameter to verify the weld-quality after a homopolar pulsed welding process.

Abstract: A welding voltage value Vf and a welding current value If are respectively monitored by a detector during execution of arc welding in accordance with a robot operation program, indexes are calculated which show how far the monitored values Vf and If are deviated from a command welding voltage value Vc and a command welding current value Ic specified in the operation program, and it is decided that there is a possibility of occurrence of a defective weld in arc welding under execution, when the calculated index exceeds a preset threshold value. Then, the data for arc-welding execution conditions and execution results are cumulatively stored in a defective weld history data area provided in a memory in accordance with the line number and the statement of the line in the operation program for each line constituting the program, and the cumulatively-stored data is displayed on a screen.

Abstract: Control systems and methods for inspecting at least one of a plurality of parts using an inspection station are disclosed. A comparator coupled to the inspection station compares a test signal responsive to a measured parameter of a part in the inspection station to a reference signal to determine if the part matches a predetermined profile. The comparator then provides a fault signal which disables the inspection station upon determining that a part matches the predetermined profile. The profile matching part is then removed from the inspection station and stored in a storage device. The storage device then provides a confirmation signal to the comparator indicating that the profile matching part has been stored in the storage device. The comparator then enables the inspection station upon receipt of the confirmation signal.

Abstract: A method and apparatus for continuously spot-welding galvanized steel sheets overlapped to be bonded by way of a spot welding machine having a pair of electrodes. The galvanized steel sheets clamp a resistance increasing material including a spacer to ensure a gap between the sheets. Bonding surfaces of the galvanized steel sheets partly contact each other when the pair of electrodes pressurize the galvanized steel sheets such that a part of the gap is retained around the spacer between the bonding surfaces. The retained gap has a size in which zinc melted or vapored when a weld current flows between the electrodes can escape through a weld section of the galvanized steel sheets to outside. The method comprises the step of recording an inter-electrode resistance for each spot when the continuous spot welding is executed by the pair of electrodes.

Abstract: The system of the present invention includes a homopolar generator, a hydraulic uniaxial press to hold the metal alloys to be welded, and electrical connections set at selected distances from the weld interface to provide a desired cooling rate for metal alloys being welded. A method is disclosed for determining a cooling rate for a metal alloy pipe in an electrical resistance welding process in a homopolar welding system following the resistive heating of a weld interface by discharging energy from a homopolar generator through electrodes attached to each of first and second pipes to form a welded pipe segment. The temperature of the welded pipe segment is measured at periodic time intervals to determine a cooling rate for the welded pipe segment. A desired range for the cooling rate may be determined by adjusting the electrode gap for repeated samples and analyzing the resulting metallurgical properties for each sample.

Abstract: Apparatus for inspecting an electric resistance welding state including a first electrode connected to a power source, a second electrode connected to another terminal of the power source, and a welding object interposed between the first and the second electrodes. A voltage waveform measuring system includes a first analog-to-digital converter for detecting voltage applied, during a welding process, to both ends of the welding object.An electrode movement measuring system includes a sensor for detecting a change of a gap between the first and the second electrodes during the welding process, and a second analog-to-digital converter for receiving an output of the sensor.A computer system which includes a neural network inspection system for receiving outputs from the voltage waveform measuring system and from the electrode movement measuring system is provided.

Abstract: A welding machine produces a spot-welded joint between two components to be welded together by at least one electrode being in contact with one of the components, by passing a welding current through the components during a welding period, and measuring a thermo-electrical voltage between the electrode and the components outside the welding period. A method for monitoring the welding machine on the basis of the thermo-electrical voltage includes determining a monitoring variable from the thermo-electrical voltage and comparing the monitoring variable with a reference variable of the welding machine. The method can be used for regulating a welding machine, especially for producing a plurality of spot-welded joints. A device for carrying out the method includes at least one measuring instrument, in particular a voltage meter, disposed between the components to be welded together and the electrode. An evaluation and regulating device is connected downstream of said measuring instrument.

Abstract: A process for determining a temperature at a spot weld formed between two parts being made of at least one first metal by at least one electrode being made of a second metal and being in contact with one of the parts, includes determining a first measurement value for a thermoelectric voltage between the electrode and the parts prior to forming the spot weld. A second measurement value is determined for a thermoelectric voltage between the electrode and the parts after forming the spot weld. The temperature is determined by taking both measurement values into account. A device for determining a temperature at the spot weld includes at least one volt meter for ascertaining a thermoelectric voltage between the electrode and the parts, corresponding to a temperature. A control unit records at least one first measurement value for the thermoelectric voltage prior to formation of a spot weld and at least one second measurement value for the thermoelectric voltage after the formation of the spot weld.

Abstract: A method and an apparatus for ascertaining an evaluation time interval for assessing the quality of a spot weld based on a course of a temperature at the weld, call for a course of a variable which is unequivocally associated with the temperature to be ascertained for a multiplicity of reference spot welds of differing quality, and for the courses of the variable to be compared with each other. A time interval which is determined from the comparison of the courses is used as the evaluation time interval, and the courses are significantly different from each other and have a sequence which corresponds to a sequence of the qualities of the associated reference spot welds. An allocation of the quality of any spot weld can be carried out simply and precisely by using values of the temperature-dependent variable within the evaluation time interval.

Abstract: The electrical power supply cables (shunt cables) of a robotic welding machine are continuously monitored during welding operations to determine cable fatigue resulting from mechanical flexing and high electrical current flow. Increases in cable resistance, being representative of a fatigued cable, are determined by measuring voltage across the cables. When a threshold voltage level or threshold voltage increase is reached, a monitor outputs a signal alerting plant personnel of the fatigued cable. The alert signal may further provide plant personnel with a predetermined time to cold weld failure of the fatigued cable, allowing plant personnel to schedule replacement of the fatigued cable during production breaks or scheduled downtime. In one embodiment, robotic welders and associated cable monitors are networked to a centralized computer to identify and isolate fatigued cables.

Abstract: A control system and method for inspection of parts is particularly adapted for inspecting resistance welded parts in a production line environment. A displacement sensor is coupled to a welding electrode for generating a displacement sensor signal responsive to the displacement of the welding electrode during welding. A test computer evaluates the displacement sensor signal to identify defective parts and to provide a fault signal. A part containment box receives the improperly welded parts and has an input sensor for generating a signal when an improperly welded part is deposited therein. The test computer is operative to disable the production line and prevent the indexing of parts until the defective part has been removed from the production line and deposited into the part containment box which generates the input sensor signal, thereby enabling the production line.

Abstract: A thyristor voltage detector includes a current-limiting resistor having a high resistance (e.g., 30 kilo-ohm) and a switching device (e.g., photo MOS FET) of a switching photo coupler which are serially connected between a thyristor and a waveform converter (e.g., a pair of photo couplers). The photo MOS FET is turned on by a light from a light emitting diode of the switching photo coupler in respect to a high level of a switching control signal. A voltage across the thyristor is applied to the waveform converter via the photo MOS FET and the resistor. The arrangement eliminates the need for a step-down transformer, achieves downsizing and cost cutting, and reduces electric power consumption.

Abstract: A spot welding method and apparatus having electrode tips one of which is driven by a servo motor. In the method and apparatus, it is determined whether or not an abnormal condition occurs. The abnormal condition includes (a) squeezing some obstacle between the electrode tip and a workpiece, (b) a temperature adhesion of the electrode tips with the workpiece, (c) uneven pressurizing of the workpiece by the electrode tips, (d) a weld nugget dispersion, and (e) a too large electric resistance between the electrode tips and the workpiece. When such abnormal condition is detected, some counter measure is taken to prevent or decrease the abnormal condition.

Abstract: The welding quality of materials sandwiched between and welded by two electrodes is monitored by a welder monitor, which includes a detecting section for detecting a welding current and a welding voltage, an operation section for numerically analyzing, based on a heat conduction model, a temperature distribution of the two electrodes and that of the materials using the detected welding current and welding voltage, to thereby estimate a nugget diameter during welding, a reference diameter setting section for setting a reference nugget diameter, and a diameter comparing section for comparing the nugget diameter during welding with the reference nugget diameter, to thereby compute a time at which the nugget diameter exceeds the reference nugget diameter.

Abstract: Methods and apparatus for marking and identifying a commutator hook of an electric motor are provided. A preselected commutator hook is marked by deforming the hook while the armature is in a winding machine, with a known angular position. The marked hook is identified by apparatus which determines whether or not the hook has been deformed while in the winding machine, and thereby recognizing the hook.

Abstract: The present invention provides a weld control monitoring system which determines the quality of the welds in real time, and provides responsive useful outputs indicating the quality of the weld. The system permits the user to input weld data as well as quality specifications which the part must meet in order to continue the production run. A monitoring system can be used with or without programmable logic controllers and includes special program for estimating the tip wear of the welding electrodes. The present invention also includes a weld gun control in which additional support for the weld gun electrode is provided by adjacent rail structures which permit displacable movement of the electrode mounted to linear displacement welding cylinder. A sensor coupled to the piston rod of the weld cylinder provides linearly variable displacement transducer signals for use in monitoring portion of the apparatus.

Abstract: An electrical resistance welding sensor assembly useful for monitoring various resistance welding process parameters in real-time during welding operations is provided with a base element adapted to be inserted into a tapered, water-cooled, electrode tip holder, with a sensor element adapted to receive a tapered, water-cooled, electrode tip, and with an in-line integral coolant passageway extending therethrough, the sensor element having a wall component which is provided with various adhered electrical transducer devices, which conducts and transmits welding process clamping loads and electrical currents, and which is cooled by coolant flowed through the integral coolant passageway.

Abstract: Methods and apparatus for identifying the occurrence of fusing electrical attachment during fusing operations are provided. After a conventional fusing operation is complete, an electrical signal is applied to the fusing electrode while the fusing electrode is returned to its home position. The electrical signal is monitored to determine whether a circuit path exists from the fusing electrode through the fused conductors to the ground electrode. The presence of a path would indicate that the fusing electrode has become attached to the fused conductors. An alternate embodiment is also described in which the force required to withdraw the fusing electrode is monitored while the electrode is returned to its home position. If the measured force does not fall within predetermined limits, or if the measured force varies during electrode movement, fusing electrode attachment has occurred.

Abstract: A process measures the temperature of the space between one or more pieces that are subject to a rising temperature during a welding or a setting operation. Thermoelectric sources are used to form at least one of the interfaces placed between at least one electrode (5; 10,11) and the pieces (1; 13, 14) and between the pieces, to supply thermoelectricity by an electric resistance (16), to measure the current that flows through resistance (16).

Abstract: An improved fusing machine is provided that allows commutators to be balanced during the fusing process. Commutator tangs are compressed onto coil leads to form lead connections. The fusing machine compresses the tangs to varying degrees relative to the shaft. The commutator can be balanced during fusing by compressing tangs to a common radial position or by compressing diametrically opposed tangs to the same extent.

Abstract: A display is provided for indicating changes between first and second operating conditions in an appliance such as a clothes dryer. A sensing circuit senses changes in operating conditions within the appliance. A heater is connected to the sensing circuit and is responsive to various signals produced by the sensing circuit to generate heat. An elongated thermally conductive substrate is mounted adjacent to the heater for receiving and conducting thermal energy produced by the heater. A layer of thermochromic material overlies the substrate and is capable of changing colors in response to changes in the temperature of the conductive substrate.

Abstract: A method and apparatus for continuously spot-welding galvanized steel sheets overlapped to be bonded by way of a spot welding machine having a pair of electrodes. The galvanized steel sheets clamp a resistance increasing material including a spacer to ensure a gap between the sheets. Bonding surfaces of the galvanized steel sheets partly contact each other when the pair of electrodes pressurize the galvanized steel sheets such that a part of the gap is retained around the spacer between the bonding surfaces. The retained gap has a size in which zinc melted or vapored when a weld current flows between the electrodes can escape through a weld section of the galvanized steel sheets to outside. The method comprises the step of recording an inter-electrode resistance for each spot when the continuous spot welding is executed by the pair of electrodes.