Abstract: A wire feeding device configured to feed welding wire from a wire feeding source to a welding torch is provided with: an intermediate wire feeding source that is disposed between the wire feeding source and the welding torch and is configured to temporarily store the welding wire fed from the wire feeding source and to feed the stored welding wire to the welding torch; a first feeding part that feeds the welding wire at the wire feeding source to the intermediate wire feeding source; a second feeding part that feeds the welding wire stored in the intermediate wire feeding source to the welding torch; and a feed control unit that controls speed of feeding the welding wire by each of the first feeding part and the second feeding part.

Abstract: A wire feeding device configured to feed welding wire from a wire feeding source to a welding torch is provided with: an intermediate wire feeding source that is disposed between the wire feeding source and the welding torch and is configured to temporarily store the welding wire fed from the wire feeding source and to feed the stored welding wire to the welding torch; a first feeding part that feeds the welding wire at the wire feeding source to the intermediate wire feeding source; a second feeding part that feeds the welding wire stored in the intermediate wire feeding source to the welding torch; and a feed control unit that controls speed of feeding the welding wire by each of the first feeding part and the second feeding part.

Abstract: A wire feeding mechanism includes feeding rollers and a cushioning mechanism. The feeding rollers feed a wire, which is drawn from a wire supply source, along a predetermined feed path. The cushioning mechanism is arranged between the wire supply source and the feeding rollers. The wire has an intermediate portion that extends from the wire supply source to the feeding rollers. The cushioning mechanism applies tension to the intermediate portion while the length of the intermediate portion is changing.

Abstract: A wire feeding mechanism includes feeding rollers and a cushioning mechanism. The feeding rollers feed a wire, which is drawn from a wire supply source, along a predetermined feed path. The cushioning mechanism is arranged between the wire supply source and the feeding rollers. The wire has an intermediate portion that extends from the wire supply source to the feeding rollers. The cushioning mechanism applies tension to the intermediate portion while the length of the intermediate portion is changing.

Abstract: A welding transformer for use in a resistance welding machine has primary and secondary coils. The primary coil includes a plurality of spaced juxtaposed coil units mounted on a base board. Each of the coil units includes a plurality of juxtaposed coil unit elements with insulating members interposed therebetween. Each of the coil unit elements includes a plurality of turns of a conductive member, and a plurality of conductors mounted on the base board and electrically interconnecting the coil unit elements. A pair of cores is combined with the coil units.

Abstract: A resistance welding apparatus mounted on a robot arm includes a transformer having primary and secondary windings. Two gun arms supporting respective welding electrodes in confronting relation to each other are relatively movable toward and away from each other. Conductors extending from the secondary winding are electrically connected to one of the welding electrodes through one of the gun arms, and the transformer is supported on said one gun arm. Rectifiers are used which have terminals engaging said one gun arm and opposite terminals engaging the conductors. The rectifiers and the conductors are securely joined to the one gun arm.

Abstract: A welding gun assembly includes a welding gun with a pair of electrodes for welding workpieces together therebetween. The welding gun assembly includes an array of transformers extending in one direction and having respective secondary coils. The welding gun assembly also has a plurality of terminal plates connected to the secondary coils, and a plurality of center tap terminal plates connected to intermediate portions of the secondary coils. A first conductor plate extends along the transformer array and interconnects the terminal plates, the first conductor plate being connected to one of the electrodes of the welding gun. A second conductor plate extends along the transformer array and interconnects the center tap terminal plates, the second conductor plate being connected to the other electrodes of the welding gun.

Abstract: A transformer apparatus for use with a welding gun includes four transformer/rectifier assemblies each including a transformer having a secondary winding and a rectifier, a terminal plate connected to the secondary winding through the rectifier, and a center tap terminal plate connected to an intermediate portion of the secondary winding. The terminal plate and the center tap terminal plate are disposed on one side of the transformer, and the transformers of the transformer/rectifier assemblies are disposed side by side. The terminal plates of the transformer/rectifier assemblies are disposed closely to each other in confronting relation. First and second conductive bodies interconnect the terminal plates and the center tap terminal plates of the transformer/rectifier assemblies. The transformer/rectifier assemblies are symmetrically disposed.

Abstract: Change in outputs from a pair of distance sensors mounted on a pair of gun arms is monitored to determine whether or not the gun arms have started to move toward opening to activate the robot carrying the welding gun. If no change in output occurs in either sensor when an instruction is given to open (generally because a fusion weld of the electrode to the workpiece has occurred), an alarm is activated and the robot is not.

Abstract: The opening degree of the two arms of a welding gun movable by a robot to a plurality of welding spots, each of the arms being equipped with an electrode tip, is detected when the arms are closed with no work clamped between them and compared with a lower-limit opening degree value. The lower-limit opening degree value is previously set to be equal to the opening degree experienced when the electrode tips are reduced to their lower usability limit. The comparison determines if the tips need to be replaced. After replacement, the opening degree observed with the gun closed with no work clamped between the tips is compared to an upper-limit opening degree value, previously set, to operate an alarm if a defective tip or an incorrectly mounted tip is present.

Abstract: A welding control apparatus and a method for controlling thereof for automatic welding machines having a welding gun successively moved by a robot to a plurality of welding spots on a work object for welding is disclosed. The welding control apparatus and the method for controlling thereof detect any abnormal conditions for preventing damages to the gun or undesired occurrence of holes in the work object.

Abstract: A transformer with a rectifier is disclosed, wherein a transformer main body, having therein a primary coil and a secondary coil, is provided at its front surface with a secondary electrode plate connected to the secondary coil, and to secondary electrode plate is connected at its front surface to a terminal plate through a rectifier, and the two plates are fastened together by means of bolts, or the like, characterized in that the rectifier is formed of a semiconductor element comprising a semiconductor layer of silicon, or the like, having front and rear holding plates of molybdenum, or the like, the semiconductor element is held between metallic plated layers of gold, silver or the like previously formed on mutually facing inner surfaces of the two plates, and a frame seal member made of silicon rubber or the like surrounding the element is held between the two plates.

Abstract: A welding gun apparatus having a gun bracket, a pair of arms pivotally mounted on the bracket, a transformer mounted on the bracket, and a pressure applying mechanism on the bracket for opening and closing the gun arms; characterized in that the gun bracket comprises a frame which extends longitudinally from a front pivot portion for pivotally supporting the gun arms to a rear portion, the transformer being positioned in and fixed to the frame between the front pivot portion and the rear portion.