Patent ID: 7053331

Claim:
A stud welding method for welding a stud held retained in a stud holding device of a stud welding head to a workpiece, comprising the following steps: a) moving said stud holding device towards the surface of the workpiece at least until a face of said stud holding device contacts the surface of the workpiece; b) separating said stud holding device from the workpiece a predetermined distance between said face of said stud holding device and the surface of the workpiece; c) inserting the stud to be welded into the stud holding device, wherein the stud projects from said face of said stud holding device a predetermined length; d) moving said stud holding device towards the surface of the workpiece until contact between the stud and the workpiece is detected, and determining the distance said stud holding device was moved from the position that was reached after step b) until contact with the workpiece is detected; e) comparing the distance determined in step d) with the distance determined in step b), wherein the presence of the stud is assumed if the difference between the distance determined in step d) and step b) exceeds a predetermined distance by a predetermined amount; f) conducting the welding operation if the presence of the stud is assumed.