Thermionic insulated arc welding gun

Claim 1

In an arc welding gun for feeding continuous lengths of consumable electrode in an arc welding process and which includes a handle member having a bore through its total length, the combination therewith comprising: a main tubular trunk for conducting welding current through its wall and consumable electrode through its bore to a head assembly of the arc welding gun, said main tubular trunk having means at a downstream end connecting said main trunk to the head assembly of the arc welding gun, said main tubular trunk extending into the bore of said handle member and having means at an upstream end thereof connecting said main trunk to a welding cable, said main trunk comprising an inner electrically conductive metal tubular member encased within a snug-fitting second tube of unitary electrical insulating and substantially ion-impervious material, said second tube being encased within a third snug-fitting tube of thin gauge metal: and means suspending the portion of said main tubular trunk extending into the bore of said handle member to provide a space between the wall of the bore of said handle member and the outer periphery of said third tube of said main trunk for the circulation of cooling air through the bore of said handle member said suspending means comprising, one or more collars through which said main trunk is telescoped, each of said collars being rigidly attached to the outer periphery of said third tube of said main trunk and having outwardly extending projections spacing said collar centrally within the bore of said handle member and attaching said collar to said handle.