Apparatus for extending broad metal surface areas with a magnetically impelled arc

Apparatus for electric arc graining a workpiece having an electrically conductive, substantial surface area during travel of the workpiece and surface area past the apparatus, said apparatus comprising:

• at least one electrode including an elongated loop body portion and a continuous elongated loop tip projecting laterally from a general plane of said elongated body portion;
• means for establishing an arc between said tip and said workpiece;
• magnetic means located in close proximity to said loop electrode and including a continuous coil elongated in the direction of the elongated loop body portion;
• an elongated first closed loop ferromagnetic pole member spaced outwardly around and generally concentric with said loop tip and continuous coil;
• a second elongated ferromagnetic pole member opposite in polarity to said first pole member and having a continuous surface disposed generally within and substantially concentric with said loop electrode tip;
• and
• means for energizing said coil whereby an arc established between said tip and the workpiece is moved by a magnetic field extending between the pole members in a continuous repetitive manner about the loop of the electrode tip and across the workpiece as the workpiece and surface area travel past the arc and electrode tip.

A magnetically impelled arc producing device comprising:

• an elongated electrode having a continuous loop configuration and a continuous elongated loop electrode tip extending laterally from a general plane of the electrode and about which an arc established between the tip and a workpiece surface can be repetitively impelled, and an open center containing a hollow member elongated in the direction of the loop electrode and tip and extending generally perpendicular through the plane of the electrode loop and having one end located in the vicinity of the continuous electrode tip,
• at least one elongated continuous electromagnetic coil located adjacent the plane of the electrode loop and about the hollow member, and providing a magnetic field when supplied with electrical current, and
• an elongated housing surrounding the loop electrode, magnetic coil and hollow member, said housing including a continuous wall portion extending inwardly toward the elongated electrode tip,
• said hollow member and housing, including said inwardly extending wall portion, being made of ferromagnetic material that conducts the magnetic field provided by said coil between the one end of the hollow member and the inwardly extending wall portion of the elongated housing to provide magnetic poles of opposite polarity at the locations of the inwardly extending wall portion and the one end of said hollow member in the vicinity of the continuous electrode tip.

Apparatus for extending at least one surface of an electrically conductive material having a substantial surface area and traveling relative to a location containing the apparatus, the apparatus comprising:

• support means at said location for receiving said conductive material in intimate contact therewith, as the material travels against said support means, said support means having a ground potential that the conductive material assumes upon intimately contacting the support means,
• at least one continuous loop electrode for producing an electrical arc at the location at which the conductive material travels against the support means, and having a positive electrical potential with respect to the support means and conductive material such that an arc can be struck between the electrode and material;
• said loop electrode having an elongated configuration, with its major axis extending across the conductive material;
• and
• continuous elongated magnetic means having its major axis extending across the conductive material located adjacent said elongated electrode for moving said arc repetitively along the loop of said electrode and in contact with the substantial surface area to traverse said area as the material travels against the support means.

Apparatus for extending a surface of a workpiece having a generally planar, substantial surface area with an electric arc, as the workpiece travels past the apparatus and electric arc, comprising:

• an elongated ferromagnetic channel structure for housing in a generally concentric manner an elongated loop electrode, a continuous elongated electromagnetic coil extending in a direction generally parallel and in close proximity to a general plane of the electrode, an elongated continuous conduit means for cooling the apparatus and extending in a plane located in close proximity to said general plane of the electrode, an elongated hollow inner member made of ferromagnetic material located in the substantial center of the elongated electrode and electromagnetic coil, and means for electrically insulating the channel structure from the electrode and conduit means, and the electrode, electromagnetic coil and conduit means from each other,
• said electrode having a continuous elongated loop tip extending laterally from the plane of the elongated electrode loop,
• said channel structure having a continuous elongated end portion located outside the loop of the continuous lateral electrode tip, and
• said electromagnetic coil, when supplied with electrical current, producing a magnetic field that is coupled to the inner ferromagnetic member and to the outer ferromagnetic channel structure such that the end portion of the channel structure provides a magnetic pole of one polarity outside of the loop of the continuous elongated tip, and the inner member provides a magnetic pole of opposite polarity inside the loop of the continuous tip, said poles being located in a substantially common plane, which plane lies substantially in a plane occupied by the continuous lateral tip of the electrode such that an arc struck between said tip and a workpiece can be repetitively impelled about the loop of the tip.