Abstract:
A pack for batteries or other electrical storage devices, such as capacitors, is designed for ease of manufacture and installation of components in the case with vertical motions to provide an efficient and cost effective assembly. An exemplary embodiment has a molded case and cover in which all of the internal components are installed in the case through the open top without requiring fasteners, tools or additional supporting parts. The components include a flexible circuit on a flexible plastic sheet carrying control and sensor circuitry and temperature sensors together with internal and external connectors. Buss bars and connecting terminals mount in vertical slots and include prongs that extend through flexible flap connectors into guide recesses to provide connections to the flexible circuit. Batteries with vertical blade terminals are received in slots of the buss bars. An electronic control module and current sensor are also provided.

Description:
TECHNICAL FIELD  
         [0001]    This invention relates to electrical energy storage and supply packs, including packs of batteries, capacitors, including ultra capacitors, or other such electrical energy storage devices, primarily for use in vehicles. More particularly, the invention pertains to a pack in which multiple electrical storage devices such as batteries, buss bars and other components are mounted in a case through an open top using downward motions without the use of fasteners, tools or extra parts.  
         BACKGROUND OF THE INVENTION  
         [0002]    It is known in the art relating electrically powered vehicles, including hybrid vehicles, to provide a battery pack with a plurality of batteries connected to provide adequate power, energy and voltage for operating a vehicle. Such a pack may include a plurality of batteries or cells mounted in a case and connected in series to obtain the necessary voltage, energy and power. Additional components, such as buss bars or other connectors, control circuits, sensors, controllers and various supports and fasteners for mounting the components may also be provided.  
         SUMMARY OF THE INVENTION  
         [0003]    The present invention provides a battery pack, capacitor pack, or other electrical energy storage and supply pack, having a structural enclosure, such as a molded case and cover in which all of the internal components are installed in the case through the open top without requiring fasteners, tools or additional supporting parts. The case and components are configured for preferred installation of the components with generally vertical downward motion.  
           [0004]    A flexible circuit on a flexible plastic sheet placed in the bottom of the case carries control and sensor circuitry and temperature sensors together with internal and external connectors. Buss bars with connected terminals mount in vertical slots on opposite sides of the case and include prongs that extend through flexible flap connectors into guide recesses to provide connections to the flexible circuit. Batteries with vertical blade terminals are received in slots of the buss bars. An electronic control module carried in wall slots is plugged into the internal connector for reading and controlling the batteries through the flexible circuit. A current sensor is mounted on one of the battery terminals. All these components are designed for ease of manufacture and installation in the case with vertical motions to provide efficient and cost effective manufacture and durability. The enclosure case and cover include ventilation openings for passing air to maintain suitable battery temperatures.  
           [0005]    These and other features and advantages of the invention will be more fully understood from the following description of certain specific embodiments of the invention taken together with the accompanying drawings. The terms battery and batteries as used herein are intended to include other types of electrical storage devices which may be used in place of batteries in a pack of the type described. Capacitors, including ultra-capacitors, are examples of such devices. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]    In the drawings:  
         [0007]    [0007]FIG. 1 is an exploded view of an exemplary embodiment of battery pack in accordance with the invention;  
         [0008]    [0008]FIG. 2 is a pictorial view from a lower corner of the battery pack partially broken away to show the internal components;  
         [0009]    [0009]FIG. 3 is a cross-sectional view from the line  3 - 3  of FIG. 2 showing the buss bar circuit connections;  
         [0010]    [0010]FIG. 4 is a cross-sectional view from the line  4 - 4  of FIG. 2 showing the battery to thermal sensor interface; and  
         [0011]    [0011]FIG. 5 is a cross-sectional view from the line  5 - 5  of FIG. 3 showing the buss bar mounting and battery interface. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0012]    Referring now to the drawings in detail, numeral  10  generally indicates an exemplary embodiment of a battery pack, or other electrical energy storage and supply pack, in accordance with the present invention. Battery pack  10  includes a structural enclosure  12  containing separately assembled components including a flexible circuit  14 , positive and negative terminals  16 ,  18 , buss bars  20 , batteries (or capacitors)  22  and an electronic control module (ECM)  24 .  
         [0013]    Enclosure  12  includes a case  25  preferably molded of a material having substantial strength and electrical insulating characteristics. The case  25  has a generally rectangular bottom wall  26  connected at peripheral edges  28  with enclosing opposite side walls  30 ,  32  and opposite front and rear end walls  34 ,  36  extending to an open top  38 . A preferably molded cover  40  is mounted on the walls and closes the open top. The cover may be secured to the case by suitable fasteners, not shown, or may be permanently attached as by adhesive material or otherwise. The bottom wall  26  and the cover  40  are provided with air openings  42  for passing cooling air through the case  25 .  
         [0014]    Internally, the side walls  30 ,  32  include guide ribs  44  defining vertical slots  46  for locating the buss bars  20  and terminals  16 ,  18 . The front end wall  34  includes guide ribs  48  with vertical slots  50  for locating the ECM  24  and connector  80 . A connector cutout  52  is also provided in an upper edge of the front end wall. The rear end wall  36  includes unslotted cover support ribs  54 . The bottom wall  26  includes support pads  56  along both sides having guide recesses  58  spaced along the side walls  30 ,  32  between their ribs  44 . Separators  59  (shown in phantom in FIG. 1) extend upward for spacing the batteries  22  apart. Similar separators  60 , (FIG. 4) projecting down from the cover  40 , may be provided to maintain separation of the batteries. Openings  61 ,  62  are also provided for the positive and negative terminals  16 ,  18 .  
         [0015]    The flexible circuit  14  has an insulating flexible sheet  64  on which is applied an integrated circuit with a plurality of conductors, not shown. The sheet  64  carries various spaced devices and features with open areas between to allow for the passage of cooling air within the case. Along outer edges, the sheet  64  provides longitudinally spaced contact openings formed by flexible flaps  66  coated with electrical contact material  68  connected with individual conductors, not shown, of the flexible circuit  14 .  
         [0016]    Centrally, sheet  64  carries a row of longitudinally spaced temperature sensors  70 , also connected in the flexible circuit  14 . A strip of resilient material  74 , such as expanded foam, is carried beneath the sheet  64  under the sensors  70  to urge them upward. Additional resilient strips  76  are carried on an upper surface of the sheet  64  between the outer edges and the sensors  70  to resiliently support the batteries  22 . Similar resilient strips  77  may also be provided beneath the cover  40  to hold the batteries firmly in their desired positions. An internal control connector  78  is provided on the sheet for connecting the circuit  14  to the ECM  24 . An external control connector  80  is also connected at the end of an extended portion  81  of the circuit  14 .  
         [0017]    The positive and negative terminals  16 ,  18  are, respectively, female and male single post connectors  82 ,  84  for carrying the battery current to an external load. Both terminals are preassembled with buss bar portions having guide blades  86  that are received in vertical slots  46  at opposite ends of side wall  30  and include female blade connections  88  for connecting the post connectors  82 ,  84  with the batteries  22 . The female post connector  82  is aligned by the slots  46  with the opening  61  in the case bottom wall  26 . The male post connector  84  is aligned by the slots and extends through opening  62  of the bottom wall. A current sensor  89  is fitted on the male connector and remains above the bottom wall  26 .  
         [0018]    The buss bars  20  are also provided with guide blades  90  received in others of the vertical slots  46 . The buss bars have dual female blade connections  88  connecting the ends of adjacent batteries  22  with one another. Prongs  92  extend downward to connect the buss bars with the contact material  68  on the flaps  66  of the flexible circuit  14 . The electronic control module (ECM)  24  and the connector  80  also include guide blades  94 ,  95  receivable in the vertical slots  50  for positioning these components on the front end wall  34 . There the ECM  24  plugs into the internal connector  78  of the flexible circuit and the external connector  80  may be connected with an external circuit through the cutout  52  in the front wall  34 .  
         [0019]    The batteries  22  in the illustrated battery pack  10  consist of ten lithium polymer units having cells enclosed by elongated and relatively flat metal shells or containers  96 . Other numbers and forms of batteries and other materials for the containers may be used if desired. The ends of the containers are insulated and internally connected to carry electric current to positive and negative male blade terminals  98 ,  100 , mounted on the container ends. The flat walls of the containers are spaced apart slightly to provide space for passing cooling air between the batteries for temperature control.  
         [0020]    Assembly of the exemplary battery pack  10  is carried out in a simple and efficient manner made possible by the design of the various components described. The case  25  is positioned with the open top  38  facing vertically upward, although other orientations could be utilized if desired. The flexible circuit  14  is then placed in the case  25  with the sheet  64  on the bottom wall  26 . The opening defining flaps  66  of the circuit are aligned with the guide recesses  58  of the bottom wall support pads  56  with the electrical contact material  68  facing upward. The resilient strips  76  also face upward as do the centrally positioned temperature sensors  70  and the internal connector  78 . Resilient material  74  lies against the bottom wall underneath the central portion of the flexible sheet  64  to support the temperature sensors  70 . The external connector  80  is fitted into slots  50  adjacent the connector cutout  52 . The extended portion  81  of the flexible circuit extends downward along the front end wall  34  to the remainder of the circuit  14  lying on the bottom wall  26 .  
         [0021]    The buss bars  20 , positive and negative terminals  16 ,  18  and ECM  24  may then be installed by passing them vertically downward so their guide blades  86 ,  90 ,  94  slide into their respective vertical slots  46 ,  50  in the case  25 . The positive female post connector  82  is thus aligned with the cover opening  61  and the negative male post connector is guided into opening  62 . The buss bars  20  are moved downward so that the prongs  92  extend into the guide recesses  58  of the case, forcing the flexible flaps  66  of sheet  64  down into the recesses. This assures positive contact of the prongs with the electrical contact material  68  on the flaps and connects the buss bars  20  with associated voltage carrying conductors of the flexible circuit  14 . The ECM  24  is moved down to connect with the internal connector  78  of the flexible circuit  14  for sensing and adjusting voltage and current flow through the batteries of the pack  10 .  
         [0022]    The batteries  22  are then inserted (before or after the ECM) by moving them downward so that their respective blade terminals are fitted into the corresponding female blade connections  88  of the battery pack terminals  16 ,  18  and buss bars  20 . Adjacent batteries  22  are slightly offset laterally in the case  25  to allow for compact fitting of enlarged ends of the containers  96  and are alternately reversed to connect opposite polarities to each of the buss bars  20 . A series power circuit is thus provided through the batteries  22  from the post connector of the terminal  16  to the post connector of the terminal  18 . If desired, the buss bars and batteries could be arranged to provide parallel or series parallel circuits within the scope of the invention. Upon installation, the battery containers  96  directly engage the temperature sensors  70  of the flexible circuit so that the temperature of each battery container may be monitored during operation.  
         [0023]    Installation of the cover  40  on the case  25 , whether by screws, adhesive or other means, encloses the components in the structural enclosure  12 . The cover mounted separators  60  and the resilient strips  77  help maintain the batteries apart and urge the batteries down against the resilient strips  76  on the flexible sheet  64 , thus providing a rattle free mounting. The lower strip of resilient material  74  is also compressed and urges the temperature sensors  70  continuously against the battery containers  96  to assure consistent heat transfer conditions and reliable temperature readings.  
         [0024]    The use in the specification and claims of directional terms, such as bottom wall, side walls, front and rear end walls and open top, is not intended to limit the manner of use or assembly of the pack to any particular orientation. However, FIG. 1 does indicate a preferred, but not required, orientation for assembly wherein the open top of the case is facing upward during installation of the components.  
         [0025]    While the invention has been described by reference to certain preferred embodiments, it should be understood that numerous changes could be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the disclosed embodiments, but that it have the full scope permitted by the language of the following claims.