Patent ID: 7408756
Filing Date: 2008-08-05
Classification: B23K

Abstract:
1. An electro mechanical contactor device in a wire feeder for an electric arc welder having a power source and a gun with a contact tip through which welding wire is fed and a weld cycle start trigger switch having a closed condition to initiate and hold a weld cycle and an open condition, said contactor device comprising: a power inlet lead connected to said power source, an output lead connected to said contact tip, a plurality of current branches between said input lead and said output lead with a mechanical contactor having an open condition and closed condition for opening and closing each of said branches, respectively, and a single solenoid operating said contactors in unison based upon the condition of said trigger switch, with a first position to close said contactors in unison when said trigger switch is shifted from said open condition to said closed condition and to hold said contactors closed when said trigger switch is in said closed condition; said contactor device further including a temperature sensor associated with each of said branches, said sensor including a circuit to create a signal when the temperature of said branch exceeds a preset value and a circuit for blocking said solenoid from shifting to said first position upon creation of said signal.