Abstract:
A cell connector bar or strap for connecting or coupling electric cells, both electrically and physically, is provided with a heat-sink for dissipating heat generated by the cells when charging rechargeable cells and during rapid discharge of the battery formed by the coupled cells. The heat-sink, in its preferred structure is a plurality of heat dissipating elements, such as extending fingers, extending from the body of the cell connector bar.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to electrically conductive straps or bars that provide both physical and electrical connections between terminals of electric cells, for forming batteries. 
     2. Prior Art 
     Electric batteries are made from electric cells. In the process of making an electric battery, a plurality of electric cells, usually referred to as ‘dry cells’, are electrically and physically combined into the electric battery. The design of an electric cell and the quality of the material from which the cell is made usually determines the electric characteristics of the cell. Battery cells or dry cells are manufactured to meet specific specifications, established by the manufacturer. However, although the dry cells produced in the same manufacturing run by the same manufacturer are designed to have the same materials, specifications and electric characteristics, the electric characteristics vary in quality from cell to cell. A process of cell grading is instituted in order to assemble the cells having substantially similar quality electric characteristics. The highest quality electric battery is a battery combined from electric cells having electric characteristics of high and uniform quality. 
     Heat is the enemy of electric cells and therefore the enemy of electric batteries made from a plurality of cells. It is most desirable to limit and/or keep heat away from battery cells. In order to connect a plurality of cells into a battery, good physical and electrical connections between cells are required. Contemporary cells are made using metal cans and caps because metal is the best conductor of electricity. In order to connect cells into a battery, a cell bar of metal is used. Most assemblers of batteries heat-solder the cell bar to the cell. Some assemblers spot weld the cell bars to cells with multiple spot welds. The cell bar connection process generates a large amount of heat which is conducted to the cell parts. When electrically charging the cells of a battery, the charging process generates heat and with rapid discharge of the battery, such as used in racing electric vehicles, a great amount of heat is generated. The heating of a cell and the retention of heat by the cell degrades the characteristics of the cell and eventually destroys the electrical functions of the cell. 
     SUMMARY OF THE INVENTION 
     The present invention provides an improved cell bar for electrically and physically bridging or connecting each of two cells, in a plurality of cells, for forming a battery. The improved cell bar is defined by a strip or bar of good to excellent electric conductive material, such as copper or gold, for example, and good to excellent heat conductive characteristics, such as copper or nickel, for example. Preferably, a cell bar is defined by a base or center of copper with an integrated exterior of nickel however, a cell bar of solid copper or another combination of good to excellent electric conductive and heat conductive materials may be used, if desired. 
     The cell bar includes a heat sink, preferably in the form of a plurality of fingers, connected to and/or integrated into and extending from one or more of the side edges of the cell bar and preferably comprised of good to excellent heat conductive material. One or more holes may be made in the heat sink fingers for increasing the surface of the heat sink for more rapid heat dissipation. The holes may be located in the fingers and/or cell bar, as desired. The heat sink fingers preferably are fabricated from good to excellent heat conductive material and extend from the edge of the side of the cell bar. Preferably, the fingers are spaced from each other for good air circulation and heat dissipation. The heat sink fingers may extend from one side of the cell bar or from both sides of the cell bar and may be uniformly spaced or twisted, for inducing air flow, as desired. The heat sink fingers and/or the cell bar may include one or more holes, the diameter of which is less than the thickness of the finger or cell bar, in which the hole is made, so that the surface of the heat sink function is increased for greater and faster heat dissipation. The heat sink fingers may be extended straight or may be curved. The fingers may be extended at the same angle from the cell bar edge or at different angles, with respect to the horizontal and/or the vertical reference. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIGS. 1 a  and  1   b  represent a prior art cell bar and a plurality of cells with connecting cell bars; 
     FIG. 2 is a representation of the invention, in pictorial view; 
     FIG. 2 a  is a cross section view of part of the invention represented in FIG. 2, along line a—a thereof; 
     FIG. 3 represents an alternate embodiment of the invention; 
     FIG. 3 a  represents a cross-cut view of surface-increasing holes, represented in FIG. 3; and 
     FIG. 4 represents a plurality of cells individually connected using the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 1 a  and  1   b  represent a cell connector bar and use thereof for connecting cells, using prior art technology. A cell connector bar  10  is a metallic strip or bar sufficiently long to make connection, both physically and electrically, with two adjacent cells. Connection may be a series electrical connection or a parallel electrical connection, connecting terminals of adjacently positioned cells, for forming a battery. Cells  11  and  12  are connected by the cell connector bar  17  and cells  12  and  13  are connected by the cell connector bar  18 . The cells are connected in a series electrical format. The positive terminal  19  of cell  11  is connected to the negative terminal  20  of cell  12 . The positive terminal of cell  12  is connected to the negative terminal of cell  13 , in a classic format for providing a battery having voltage that is increased over the voltage of the individual cells. Connection between the cell connector bar and the cell may be accomplished by heat soldering or welding, as is well known in the art. While electrically connecting cells  11  and  12 , for example, the cell connecting bar or strip also hold cells  11  and  12  physically oriented, with respect to each other. The cell connector bar  18  connects cells  12  and  13  both electrically and physically. 
     FIGS. 2,  2   a ,  3  and  4  represent aspects of the present invention and use of the invention. Electrically and physically connecting two cells, in series connection. FIG. 2 represents a preferred embodiment of the invention, where a cell connector bar or strap  21  includes a body  22  and appended feet  23  and  27 . Between each foot  23  and  27  and the body  21  are canted areas  28  and  29  respectively, that raise the body above and over rims of cells when the cell bar is connected to each of two cells, essentially bridging the cells. Extending from, or connected to the side of the body  22  of the cell connector bar  21  are a plurality of spaced heat-sink elements or fingers  30 . Preferably, the fingers  30  are each an extension of the body  22 , spaced for permitting air flow between the fingers for defining a heat-sink element. 
     The cell connector bar may be a solid material, such as copper, for example or may be a clad or coated material, such as a core of copper, for example and a coating of steel. The heat-sink fingers, which may be extensions of the body or connected to the body, may be fabricated from the same material from which the body is fabricated. In a preferred embodiment, the body and feet of the cell connector bar are fabricated from a metal core of copper, which is an excellent electric conductor and includes a coating or is clad with a material which is an excellent conductor of heat. The fingers of the heat-sink are fabricated from the coating or clad material for more efficient heat dissipation. If desired, a layer of solder material  31  and  32  may be pressed or rolled on to the under surface of each foot  23  and  27 , respectfully, for soldering purposes. 
     FIG. 2 a  is a view of the invention represented in FIG. 2 along the line a—a, showing the fingers  30  extending angularly from the body  22  of the connector bar. The fingers  30  may extend out straight or may be angled, as represented. The fingers may be uniformly elevated or elevated at different angles, as desired. The fingers  30  may be straight or twisted to vary the air space between the fingers, for more efficient heat dissipation. When the connector bar is fabricated from clad materials, one material having greater electric conducting characteristics than heat dispensing characteristics and a second material having greater heat dispensing characteristics than electric conducting characteristics, the fingers are preferably extensions of and are fabricated from the material having the best heat dispensing characteristics. 
     FIG. 3 represents an alternate embodiment of the invention in which heat-sink fingers  33  extend from one side of the body  37  and heat-sink fingers  38  extend from the other side of the body  37 . In addition, the heat-sink members  33  and the body  37  are provided with holes,  39 , which extend between the surfaces thereof. As represented in FIG. 3 a , the holes  39  have a diameter ( 2 — 2 ) which is inferior to the thickness of the body  37  ( 1 — 1 ), for increasing the surface of the material forming the body and forming the fingers for more efficient heat dissipating purposes. FIG. 3 a  also represents that the body may be fabricated from a clad material, that is, the center material of the body and the feet may be copper, for example and the outer material or cover may be steel, for example. 
     The function of the cell connector bar is primarily to conduct electricity between cells. It is well established that copper is an excellent conductor of electricity and copper is a preferred material for forming cell connector bars. Further, is well known that low voltage electricity travels primarily on the inside of a conductor making copper metal the preferred metallic core of a bi-metallic cell connector bar. As is also well known, steel, though a conductor of electricity is inferior to copper, as a conductor of electricity but superior to copper as a conductor of heat. Thus, a steel clad/copper core fabrication is a preferred combination for a clad cell connector bar, although other combinations of materials may be used, if desired. 
     FIG. 4 represents the use of the invention in connecting a plurality of cess into a battery. A cell connector bar  47 , with a single heat-sink member may be used or a cell connector bar  43 , with a double heat-sink member may be used to connect cells. The cell connector bar  41  may include heat-sink fingers which extend from the far side of the body of the bar. 
     It will be apparent to one skilled in the art that the terminal  48 , extending from the positive terminal of cell  49 , may represent one terminal, the positive terminal, of a battery and that the second or negative terminal of the battery is not shown. 
     In the foregoing description of the invention, referenced to the drawings, certain terms have been used for conciseness, clarity and comprehension. However, no unnecessary limitations are to be implied from or because of the terms used, beyond the requirements of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed. Furthermore, the description and illustration of the invention are by way of example, and the scope of the invention is not limited to the exact details shown, represented or described. 
     Having now described a preferred embodiment of the invention, in terms of features, discoveries and principles, along with certain alternative construction and suggested changes, other changes that may become apparent to those skilled in the art may be made, without departing from the scope of the invention defined in the appended claims.