Patent ID: 7399941
Filing Date: 2008-07-15
Classification: B23K

Abstract:
1. A welding tool comprising: a welding head; a refractory electrode carried by said welding head; an inert gas feed positioned to feed inert gas to said welding head in order to protect a weld bead against oxidation; and a skirt made of a semirigid refractory material surrounding said refractory electrode; wherein the skirt comprises a substantially cylindrical top portion mounted on said welding head and a bottom portion of downwardly flaring shape, wherein said top portion of the skirt comprises a releasable fastener configured to fasten the skirt on said welding head, wherein said bottom portion of the skirt has an extended forward portion relative to a rear portion to guide the inert gas over a greater length of the weld bead, said forward portion being curved in a concave manner around the weld bead so as to form a gas outlet at the front around the weld bead, wherein said skirt includes a molded or thermoformed composite material including at least two layers of ceramic fibers which are bonded together by at least one elastomer layer that withstands high temperatures, and wherein said refractory electrode extends along an electrode axis, and said bottom portion of said skirt is not symmetric around said electrode axis such that said front portion of said bottom portion of said skirt extends further away from said electrode than said rear portion of said bottom portion of said skirt extends from said electrode, wherein said rear portion is opposite from said front portion.