Patent ID: 7141753

Claim:
An arc stud welding device comprising a welding gun holding a stud at a tip, a linear motor for bringing the held stud into contact with, and disengaging the stud from contact with, a base material, a position sensor for detecting the position of the stud held at the tip of the welding gun with respect to the base material, a power source for supplying power to the stud held at the tip of the welding gun and the base material, and a controller for generating an arc discharge between the stud and the base material to weld the stud to the base material, wherein the controller applies power from the power source to the base material and the stud in contact with the base material, operates the linear motor to pull up the stud from the base material, generates a main arc with a main current after a pilot arc has been generated, and operates the linear motor to press the stud against the base material and weld the stud to the base material, and wherein the controller includes a disengagement detector for detecting when the stud disengages from the base material, and the controller receives a signal from the position sensor when the stud disengages from the base material, to establish a disengaged position, and the linear motor is then operated to pull up the stud from the disengaged position to a predetermined position that is a predetermined distance from the disengaged position.