Abstract:
An electrical bus forming method including the steps of interlocking a plurality of electrical conductors and forming a shaped conductor. The interlocking step includes interlocking a plurality of electrical conductors including a first electrical conductor with a second electrical conductor thereby forming an interlocked conductor. The forming step includes forming a shaped conductor from the interlocked conductor.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This is a non-provisional application based upon U.S. provisional patent application Ser. No. 60/813,861, entitled “ELECTRICAL LOCKED CONNECTION”, filed Jun. 15, 2006. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to electrical conductor assemblies, and, more particularly, to electrical bus bars and a method for making electrical bus bars. 
     2. Description of the Related Art 
     Electrical conductors for use in the delivery of power and signals to circuit components are known in the art as bus bars. Bus bars are electrically conductive, and are commonly made of copper. Bars of copper are often shaped by a forming die to cut and to form the copper into a shaped bus bar. Bus bars can include connection points, such as spade connectors made with parts of the bus bar that are cut and shaped to form points of interconnection. The shaping of bus bars to include interconnection points eliminates the need for a terminal or interface lug to be connected to the bus bar for the transfer of power from the bus bar to another circuit component or an additional bus bar. 
     Bus bars that have interconnections that extend significantly from the main body of the bus bar create problems associated with scrap in the manufacture of the formed bus bar. For example, if a bus bar is being made having a length of 4 feet, and has a main body width of 1 inch the blank needed to form the bus bar will need to be 4 feet long by an inch plus the length of the circuit interconnections that would extend therebeyond for the width. So if one interconnection extends 2 inches from the edge of the finished bus bar in one direction and a ½ inch from the other side of the bus bar then a blank 3½ inches wide must be utilized to cut the 1 inch body with extensions extending two inches on one side and a ½ inch on the other. Whether there are numerous 2 inch extensions or merely one, the blank area required to stamp out the bus bar would remain at 3½ inches, thereby potentially creating considerable waste. 
     What is needed in the art is a method to produce a bus bar with minimal scrap utilized in the process of forming the final desired shape. 
     SUMMARY OF THE INVENTION 
     The present invention provides a method for producing a shaped bus bar from a plurality of interlocked electrical conductors. 
     The invention in one form is directed to an electrical bus forming method including the steps of interlocking a plurality of electrical conductors and forming a shaped conductor. The interlocking step includes interlocking a plurality of electrical conductors including a first electrical conductor with a second electrical conductor thereby forming an interlocked conductor. The forming step includes forming a shaped conductor from the interlocked conductor. 
     An advantage of the present invention is that a bus bar assembly can be manufactured with considerably less waste than prior methods. 
     Another advantage of the present invention is that the attached conductor can be bent without consideration of adding relief cuts to the blank during the cutting operation. 
     Another advantage of the present invention is that the interlocking features provide more conductivity than the cross-sectional area of the material that is bent to form an interface connector in the prior art. 
     Yet another advantage of the present invention is that no fasteners or soldering or braising is necessary to connect the conductors in the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of a formed electrical bus bar. 
         FIG. 2  illustrates a blank of metal used to cut the bus bar of  FIG. 1  prior to forming the bus bar of  FIG. 1 ; 
         FIG. 3  illustrates the blank prepared for cutting and forming by a method of the present invention; 
         FIG. 4  is a cross-sectioned perspective view of an interconnection feature utilized in the bus bar blank of  FIG. 3 ; and 
         FIG. 5  is a cross-sectional view of the interconnection feature of  FIG. 4 . 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate one embodiment of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, and more particularly to  FIGS. 1 and 2 , there is shown a formed assembly  10  having electrical spade connectors  12 , an interface conductor  14  with a relief slot  16 . Formed assembly  10  is made from a blank  18  that is cut along cut lines  20 . Blank  18  results in significant amount of waste after the cutting of the unformed assembly from blank  18 . The main reason that significant waste exists in this particular instance is that interface conductor  14  extends considerably outward from the main body of the bus bar, thereby requiring a larger blank for the cutting and forming operation to result in formed assembly  10 . 
     Now, additionally referring to  FIGS. 3-5 , there is shown an embodiment of the present invention including conductor assembly  22  having a conductor  24  and a conductor  26  that overlap in an overlap area  28 . Conductor  24  is joined to conductor  26  by interlocking features  30 . Here four interlocking features  30  are utilized to connect conductor  24  to conductor  26 . Conductors  24  and  26  are electrically conductive and may be made of aluminum or copper. As can be understood, conductor assembly  22  is then cut and formed into a formed assembly  10 . An assembly  10  cut and formed in this manner is made of interlocked conductors having interlocking features  30 . While assembly  10  formed in this manner may mechanically vary in overlap area  28  as compared to forming assembly  10  from blank  18 , it does not alter the electrical functionality of a formed assembly  10  made from a conductor assembly  22  versus one made from a blank  18 . The cutting and/or forming action can be done with a stamping die in either one or two operations. If two operations are undertaken the first is done using a cutting die and the second stamping operation is a forming operation where the bus bar is stamped to bend and/or fold portions of the bus bar. 
     Conductor  24  has a thickness A and conductor  26  has a thickness B. Indentation  32  has a diameter or width C and is pressed into conductor  24  thereby forming indentation  32  with some of the material of conductor  24  being expanded outwardly at an orthogonal direction relative to the direction of indention  32 . As some of the material of conductor  24  is expanded outwardly, along with material of conductor  26 , the result is a material connection shown as interlocking features  30 . The width of interlocking feature  30  as it relates to conductor  26  is width or diameter D. The forming of interlocking features  30  corresponds to a thinning of material of conductors  24  and  26  to a thickness represented by G. In the forming of indentation  32 , an expansion  34  at an end of indentation  32  takes place so that conductor  24  and conductor  26  are locked together. The interlocking features  30 , which are illustrated as having been executed four times in overlap area  28 , results in a contact between conductor  24  and conductor  26  that is equal to or greater than the cross-sectional area of the bent portion of interface conductor  14  when formed from blank  18 . The term “interlocking” as used herein is to be understood to mean and refer to the process of displacing the material of two conductors as described above. The term “interlocked conductor” as used herein is to be understood to mean and refer to two or more conductors having being connected by the interlocking process. 
     By using conductor assembly  22  to form assembly  10  significant waste is reduced in the process as compared to the use of blank  18  to form assembly  10 . Additionally, the interlocking of conductor  24  to conductor  26  prior to the cutting and forming aspects of the operation allow for interface conductor  14  to then be accurately determined. It is the removal of some of the material of conductors  24  and  26  in the cutting process by way of a cutting process that then determines the final outer profile of assembly  10 . In contrast, if interface conductor  14  were to be later added to the assembly that has already been formed, the orientation, alignment and positioning of interface conductor  14  cannot be controlled as accurately as having conductors  24  and  26  joined prior to the cutting and forming operations. The removal of some material in the cutting process as applied to conductor assembly  22  is minimal compared to the use of blank  18 , where the amount of scrap can exceed the amount of material used in formed assembly  10 . 
     Although conductors  24  and  26  have been illustrated as being of substantially equal thickness, different thicknesses of the conductors is also contemplated. For example, in  FIG. 1 , interface conductor  14  has been folded to provide a thicker construct, which is the most practical way to provide such a structure from a blank  18 . However, using a conductor  26  that is thicker than conductor  24  precludes the need to fold interface conductor  14  to obtain the desired thicker construct. This also allows for no thinning of the cross-sectional area in the bend from interface conductor  14  to the main body. 
     The inventive method of the present invention and the assembly that results is made with reduced amount of scrap and additionally has superior electrical conductivity due to interlocking features  30 . Additionally, the interconnection of conductors  24  and  26  is accomplished without introducing another element, such as solder or a fastener. 
     While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.