Patent ID: 6903305

Claim:
A welding wire feeder for conveying a welding wire from a magazine for accommodating a welding wire therein to a welding torch, said welding wire feeder comprising: a wire feeding passage provided between said magazine and said welding torch, for conveying said welding wire therein; a plurality of wire feeding units provided in said wire feeding passage, one of said wire feeding units is located closest to said welding wire magazine out of said wire feeding units; a driving source provided in said one of said wire feeding units for generating a driving force to actuate said one of said wire feeding units; a torque limiter for transmitting said driving force to said welding wire, the torque limiter is adjustable in a torque to be transmitted; and the torque produced by the torque limiter is so that a conveying force (Fp) of said one of said wire feeding units, a resistance (Fw) to the conveying force at a static state in said wire feeding passage, and a maximum force (Fb) of bending of said welding wire satisfies the relation of 0.8Fw<Fp<Fb.