Apparatus and method for treatment of electrically conductive continuous material

#This application is a 35 U.S.C. 371 National Stage application of International application PCT/EP00/01490 filed Feb. 23, 2000.

#The invention relates to an apparatus and a method for treatment, cleaning and/or heating in particular, of electrically conductive continuous material during the movement in direction of extension thereof.

#A known apparatus of this kind is used for soft-annealing the wire material prior to a method step for diameter reduction of the wire material by transformation by means of drawing of the wire material. Furtheron, the known apparatus is used for cleaning the wire material prior to being coated with an insulating material in order to permit good adhesion of the insulating material which e.g. is applied by varnishing. The known apparatus includes an annealing furnace formed as tube through which the continuous material is transferred. The tube e.g. is heated by resistance heating and by radiation or convection transmits heat to the continuous material moved therethrough, for soft-annealing the latter. Furtheron, during said heating impurities vaporize on the surface of the continuous material and this cleaning effect can be supported in that in the furnace a particular gas atmosphere, e.g. steam, is maintained.

#In the following preferred embodiments of the present invention will be described in more detail With reference to the drawings. Herein:

#FIG. 1 in schematic view shows a first embodiment of the apparatus in accordance with the present invention, used for softannealing of wire material and

#FIG. 2 shows an electrode arrangement of another embodiment of the apparatus in accordance with the present invention.

#FIG. 1 shows an apparatus 1 in accordance with the present invention, through which a continuous material, namely a copper wire, to be treated is transferred. With respect to the apparatus 1 said wire 3 is supported by means of an inlet-side guide roller 5 and an outlet-side guide roller 7. A drive means not shown moves said wire along its direction of extension into a direction indicated by an arrow 9. The treatment of said wire 3 is carried out in a gas discharge chamber 11 in which a gas discharge surrounding said wire 3 can be generated. During said gas discharge said wire acts as cathode for which purpose it is connected through the inlet-side guide roller 5, a frictional contact not shown and a current line 13 to a current source 15. Said current line 13 furthermore lies on mass potential of the apparatus. The anode of the gas discharge is formed by a circular cylindrical steel tube 17 which centrally intersperses the said wire 3. Said steel tube 17 is electrically connected to a positive pole of said current source 15 through a line 19. By the voltage provided by said current source 15 a gas discharge can be ignited in said gas discharge chamber 11, which then will burn uniformly in that a correspondingly dimensioned and preferably adjustable pre-resistor in said current source limits the discharge current.

#To be able to provided for a gas atmosphere suitable for the desired gas discharge, in said gas discharge chamber, the latter is surrounded by an essentially gas-proof vacuum tank 21. Therein, said steel tube 17 itself is part of said vacuum tank 21. By means of a gas-proof flange connection insulation pieces 23 and/or 25, respectively, are connected the front-face ends of said steel tube 17, wherein said insulation piece 23 facing said leading guide roller 5 supports an entry lock 27 for said wire 3 and said insulating piece 25 facing said trailing guide roller 7 supports an exit lock 29 for said wire 3.

#Said entry lock 27 and said exit lock 29 respectively are formed by a drawing plate out of diamond or another hard material. Such drawing plates also referred to as drawing die or drawing hole, usually are used for transformation of said wire 3 during drawing of the wire. The inner diameter of said drawing plates 27, 29 therein is dimensioned so small that the gas passage in a gap between wire 3 and drawing plate 27, 29, is as low as possible, and it is dimensioned so large that the friction between plate 27, 29 and wire 3 also is low. Said vacuum tank 21 formed out of said steel tube 17, said insulation pieces 23, 25, said entry lock 27 and said exit lock 29 and encompassing said gas discharge chamber 11 can be evacuated through an evacuation line 31, a throughput-controllable valve 33 and a vacuum pump 35.