Abstract:
Method and apparatus for reducing corrosion of a current bar in a corrosive environment. The non-reactive metal is fused around a reactive metal creating a shell and reducing the corrosion of the reactive metal.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    The present patent application is based upon and claims the benefit of provisional patent application No. 61/644,500, filed on May 9, 2012. 
     
    
       [0002]    The present invention is intended for use with an electroplating apparatus intended to metal coat substrates of various types. The invention is specifically directed toward an improved head member for a current bar for use in providing electrical current to an anode and returning electrical current to a power supply from a cathode or substrate. 
       BACKGROUND OF THE INVENTION 
       [0003]    In a typical electroplating process a power source having an anode and a cathode is engaged with current bars. The current bars are immersed in a plating bath. The current bars supply current from the power source to an anode and returns current to the power source via the substrate to be coated or cathode. Many times current bars are constructed of copper as copper has proven to be highly efficient in transporting electrical current. The plating bath many times is of varying acidity and composition depending upon the specific metal being applied to the substrate. Typical metals used as coatings includes iridium, nickel, copper, tin, zinc, chromium, gold, silver, palladium, and platinum. 
         [0004]    The acidity of the plating bath is known to react with the copper of the current bar and very rapidly decomposes the current bar, resulting in increased maintenance and time consuming and costly replacement of the current bar. Past attempts to protect the copper of the current bar include wrapping the current bar with a metallic outer shell wherein the metallic outer shell is non-reactive with the acidic plating bath. Problems continue to be encountered however when the current bar is immersed in the plating bath and acid seeps between the outer wrap and the copper current bar. The current bar includes an unwrapped head member having exposed copper where the current bar is engaged to the power source. Thus, the gap between the copper and the metal wrap is exposed to the chemicals in the plating bath. The chemicals then seep into the gap along the entire length of the current bar. The present invention improves upon this structure for the current bar. 
       DESCRIPTION OF THE INVENTION 
       [0005]    The present invention provides a head member for a current bar that is constructed of copper fused with a non-reactive metal, such as titanium. The fusing of the metal shell to the copper eliminates the gap between the shell and the copper which previously allowed the acid in the tanks to seep into the gap between the copper and the shell and erode the copper, thus ruining the current bar. The copper head member clad in titanium provides a sealed unit, when properly attached to the current bar, which blocks the acid from seeping between the copper and the titanium, resulting in slower erosion of the current bar. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a side view of the current bar of the present invention. 
           [0007]      FIG. 2  is a top view of the current bar head of the current bar of  FIG. 1 . 
           [0008]      FIG. 3  is a side view of the current bar head of  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0009]    Referring now to  FIG. 1  a current bar  10  is shown, the current bar is composed of an L-shaped section which is used to carry the metal anode plate (not shown). The current bar is preferably constructed of copper whose outer surface is fused with a titanium layer. The metal anode plate is attached to the current bar by fasteners extending through holes  14 . The current bar includes a head member  16  which attaches directly to the power supply. 
         [0010]    Referring now to  FIGS. 2 and 3  the head member  16  is constructed of copper fused with titanium. Contact face  18  is created by machining the titanium from the copper and exposing the copper. Holes  20  machined in the current head allow a fastening member to attach the head member  16  to the power supply wherein the contact face  18  receives the electrical charge and transports it through the copper of the current bar  10 . End  22  of the head member  16  also has the titanium clad machined therefrom. The head member is thus allowed to be welded to the current bar  10 , first through a copper to copper weld, and secondly through titanium weld. Thus, the entire current bar  10  is sealed from seepage of the acidic chemicals from the plating bath through the head member  16 . The copper, with the exception of the machined face of the head member  16 , is not exposed to the chemical plating bath. In this embodiment the opposed end  24  has a titanium end cap welded to prevent exposure of the copper material to the acid bath. Thus, the invention creates a sealed unit in which the acid chemicals cannot get between the copper material and the titanium shell and erode the existing current bar  10 . If the exposed copper on the head member  16  erodes, the head member is easily removed from the current bar  10  and a replacement head member can be welded thereto. This eliminates salvaging costs for the entire current bar. 
         [0011]    While copper fused with titanium are the preferred metals for forming the current bar, those metals are not intended to exclude the use of other metals capable of achieving the desired results. This description of the preferred embodiment is not intended to limit the scope and context of the following claims. 
         [0012]    The above Detailed Description Of The Present Invention is given for explanatory purposes. It will be apparent to those skilled in the art that numerous changes and modifications can be made without departing from the scope of the invention. Accordingly, the whole of the foregoing description is to be construed in an illustrative and not a limitative sense, the scope of the invention being defined solely by the appended claims.