| 摘要 |
The present invention is directed to an improvement for an apparatus which utilizes a preheating step in which the wire heat content of a consumable electrode is increased by means other than the welding current. Thus, the invention provides in combination with at least a first source of electrical power for heating a consumable electrode, a first electrode contact tip having a bore therethrough, a second electrode contact tip having a bore therethrough and a dielectric element having a bore therethrough disposed between the first and second electrode contact tips. The bores are adapted to receive therethrough the consumable electrode for the application of electrical power thereto. The bore of at least one of the electrode contact tips is axially displaced relative to the electrode contact bore of the other electrode contact tip. The invention provides several embodiments whereby either one of the electrode tip bores or the bores of both electrode contact tips are axially displaced. By axially displacing at least one of the bores of the electrode contact tips, electric contact consistency between the consumable electrode and the electrode contact tips is maximized.
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