Abstract:
The present invention relates to a battery pack including a housing, a latch mechanism, a printed circuit board connected to electrical terminals, and an internal frame. The housing includes a first and second portion. The first portion includes openings that receive the latch mechanism and openings that receive the terminals. The battery pack also includes a latch cover that protects against water infiltrating between the openings and the latch mechanism, and a terminal cover that protects against water infiltrating between the first housing portion and the terminals. Water that enters the battery pack is directed to the bottom of the battery pack. The water is then drained through openings in the lower housing portion. The internal frame includes openings that secure batteries within the lower housing portion with the help of wedges that are positioned in between adjacent rows of batteries.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. patent application Ser. No. 13/915,621 filed Jun. 11, 2013, which claims priority to U.S. Provisional Patent Application Nos. 61/658,610 filed Jun. 12, 2012, and 61/710,390 filed Oct. 5, 2012, the entire contents of all of which are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    The present invention relates to a battery pack. In particular, the invention relates to a battery pack including water infiltration protection. 
         [0003]    The housing of a battery pack is susceptible to water ingress through openings in both a latch mechanism that secures the pack to the tool and openings that provide access to terminals of the battery pack. Introducing water into the battery pack may cause the batteries to rust, damage the internal electrical components (e.g., the circuit board), or otherwise cause battery malfunction. 
       SUMMARY 
       [0004]    In a first embodiment, the invention provides a battery pack including a housing. The housing includes an inner cavity, an interface for receiving a power tool, and drain holes on a base portion. Battery cells are positioned within the inner cavity. A first latch member and a second latch member extend through the housing and are operable to secure the battery pack to the power tool. The battery pack also includes electrical terminals electrically coupled to the battery cells and operable to interface with the power tool. A latch cover supports the first and second latch members. A first water discharge pathway extends along the latch cover, downward along a first space between the battery cells and the housing, to the drain holes such that the first water discharge pathway directs water infiltrating the battery pack to the drain holes. 
         [0005]    In another embodiment, the invention provides a battery pack including a housing. The housing includes an inner cavity, an interface for receiving a power tool, and drain holes on a base portion. Battery cells are positioned within the inner cavity. A first latch member and a second latch member extend through the housing and are operable to secure the battery pack to the power tool. The battery pack also includes electrical terminals electrically coupled to the battery cells and operable to interface with the power tool. A terminal cover includes openings that receive the electrical terminals. A first water discharge pathway extends from the openings of the terminal cover, downward along a first space between the battery cells and the housing, to the drain holes such that the first water discharge pathway directs water infiltrating the battery pack to the drain holes. 
         [0006]    In yet another embodiment, the invention provides a battery pack including a housing. The housing includes an inner cavity, an interface for receiving a power tool, and drain holes on a base portion. Battery cells are positioned within the inner cavity. A first latch member and a second latch member extend through the housing and are operable to secure the battery pack to the power tool. The battery pack also includes electrical terminals electrically coupled to the battery cells and operable to interface with the power tool. The battery pack also includes a printed circuit board coupled to the electrical terminals. Additionally, a first cover is positioned between the interface and the printed circuit board. The first cover includes at least a portion of the first cover extending along a top surface of the circuit board and an overhang portion projecting downward along a side surface of the circuit board. A first water discharge pathway extends from the first cover downward along a first space between the battery cells, to the drain holes. The first water discharge pathway directs water infiltrating the battery pack to the drain holes. 
         [0007]    In yet another embodiment, the invention provides a battery pack including a first housing portion secured to a second housing portion. The first housing portion defines an interface for receiving a power tool. The battery pack also includes a frame received within the second housing portion and constructed as a single piece. The frame includes openings, which secure a plurality of battery cells. More specifically, a pair of battery cells is stacked vertically within each of the openings and each battery cell includes a longitudinal axis oriented substantially perpendicular to a longitudinal axis of the battery pack. Further, a wedge is positioned in each opening between adjacent battery cells. 
         [0008]    Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIGS. 1-3  are perspective views of a battery pack for a power tool that includes a housing having a first portion and a second portion according to one embodiment of the invention. 
           [0010]      FIGS. 4-9  are perspective views of the battery pack of  FIGS. 1-3  having the first portion of the housing removed and including a latch cover, a terminal cover, an internal frame, and a plurality of wedges. 
           [0011]      FIG. 10  is a top view of the latch cover. 
           [0012]      FIG. 11  is a bottom view of the latch cover of  FIG. 10 . 
           [0013]      FIG. 12  is a front perspective view of the latch cover of  FIG. 10 . 
           [0014]      FIG. 13  is a rear perspective view of the latch cover of  FIG. 10 . 
           [0015]      FIG. 14  is a front perspective view of the terminal cover. 
           [0016]      FIG. 15  is a rear perspective view of the terminal cover of  FIG. 14 . 
           [0017]      FIG. 16  is a top view of the terminal cover of  FIG. 14  relative to other internal structures of the battery pack in  FIGS. 4-9 . 
           [0018]      FIG. 17  is an additional perspective view of the terminal cover of  FIG. 14 . 
           [0019]      FIG. 18  is a side view of the terminal cover of  FIG. 14  relative to other internal structures of the battery pack in  FIGS. 4-9 . 
           [0020]      FIG. 19  is a perspective view of the internal frame. 
           [0021]      FIG. 20  is an additional perspective view of the internal frame. 
           [0022]      FIG. 21  is a perspective view of a wedge of the battery pack according to one embodiment of the invention. 
           [0023]      FIG. 22  is a perspective view of a battery pack for a power tool that includes a housing having a first portion, a second portion, and a bottom cover according to another embodiment of the invention. 
           [0024]      FIG. 23  is a side view of the second portion and bottom cover of the battery pack of  FIG. 22 . 
           [0025]      FIGS. 24-25  are perspective views of the second portion and a bottom cover of the battery pack of  FIG. 22  with all internal components removed thereby illustrating a cavity of the second portion. 
           [0026]      FIGS. 26-27  are perspective views of the second portion of  FIGS. 24 and 25  with the bottom cover removed. 
           [0027]      FIGS. 28-29  are perspective views of the bottom cover of  FIGS. 24 and 25  removed from the second portion. 
           [0028]      FIG. 30  is a cross-sectional view of the second portion and the bottom cover of  FIG. 25  along  30 - 30 . 
           [0029]      FIG. 31  is a cross-sectional view of  FIG. 22  along  31 - 31  with the first portion and several internal structures removed, illustrating the second portion and the bottom cover relative to an internal frame that secures internal batteries. 
           [0030]      FIG. 32  is a side view of  FIG. 22  having a side wall removed and illustrating the second portion and the bottom cover relative to an internal frame that secures batteries. 
           [0031]      FIG. 33  is a side view of a battery pack according to another embodiment of the invention having a side wall removed and illustrating the second portion and the bottom cover relative to an alternate internal frame that secures batteries. 
       
    
    
     DETAILED DESCRIPTION 
       [0032]    Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. 
         [0033]      FIGS. 1-9  illustrate a battery pack  10  according to one embodiment of the invention. The battery pack  10  includes a housing or case  12  having a first portion  14  and a second portion  16 . The two portions  14 ,  16  of the housing are coupled, for example, by fasteners (not shown) that extend through a plurality of complementary fastening holes  18 . An interface  20  of the first portion  14 , which is symmetrical about a longitudinal axis A, is able to be physically coupled to the base of a power tool (not shown). The first portion  14  includes a first and a second window or opening  22 ,  24 , which accommodates a latch  26 . The latch  26  includes a main body portion  28  and a hook portion  30  with a connecting portion  32  extending therebetween. The main body portion  28  is received within the first opening  22 , while the hook portion  30  is received within the second opening  24 . Although only one side of the first portion  14  is visible in the illustrated embodiment, an opposite side of the battery pack includes a similar construction such that there is a latch  26  on either side of the first portion  14 . The first portion  14  further includes a plurality of openings  34  that surround terminals  36 . The openings  34  ensure the alignment of the electrical connection between the power tool and the battery pack  10 . The battery pack  10  also includes a bottom cover  38 . The bottom cover  38  includes a plurality of holes or openings  94  that are aligned with holes or openings  96  in the second portion  16  of the housing  12  ( FIGS. 2-3 ). 
         [0034]    The battery pack  10  includes a printed circuit board (PCB)  42  that is physically coupled to an internal frame  44  that secures a plurality of batteries  46  within the second portion  16  of the housing  12 . The terminals  36  project from a distal end  48  of the PCB  42  in the first portion  14 . The terminals  36  and distal end  48  of the PCB  42  are covered by a terminal block or cover  50 , while a latch block or cover  52  covers the PCB  42  on a proximal end  54 . The latch cover  52  is located below the latches  26 . 
         [0035]      FIGS. 4-9  and  19 - 20  illustrate the internal frame  44 . The internal frame  44  is constructed as a single piece and includes openings  84  and weld straps  82 . The openings  84  are sized to accommodate batteries  46  having a longitudinal axis B. The batteries  46  are secured within the openings  84  by wedges  86  ( FIGS. 19 and 21 ). The wedges  86  include a first recessed portion  88  and a second recessed portion  90  that are approximately the same size and shape as the batteries  46  such that the batteries  46  rest within the recessed portions  88 ,  90 . The wedges  86  enable the use of the different sized batteries to be stacked within the openings  84 . The weld straps  82  interconnect the batteries  46  to one another and also couple the batteries  46  to the PCB  42 . The internal frame  44  includes channels  92  that are aligned with the channels or openings  70  of the terminal cover  50  ( FIG. 7 ). In the illustrated embodiment, the batteries  46  are oriented horizontally such that the longitudinal axis B is perpendicular to the axis A of the battery pack  10 . The batteries  46  are also stacked vertically in rows within the openings  84  of the frame  44 . In further embodiments, the frame  44  includes openings  84  such that the batteries  46  are oriented in other suitable directions. Further, while the recessed portions  88 ,  90  and the openings  84  in the illustrated embodiment are substantially semi-circular and ovular, respectively, further embodiments include recessed portions and openings of alternative sizes and shapes in order to receive batteries of alternative sizes and shapes. 
         [0036]      FIGS. 10-13  illustrate the latch cover  52 . The latch cover  52  is to prevent water infiltration into the battery pack  10 , and also protects the PCB  42  by preventing water that enters the battery pack  10  between the first portion  14  of the housing  12  and the latches  26  from reaching the PCB  42 . The latch cover  52  includes a base portion  56  and an elevated portion  58 . The base portion  56  is located on an upper portion  60  of the internal frame  44 . The base portion  56  includes plurality of ridges or projections  62  and is partially visible while the battery pack  10  is assembled ( FIG. 1 ). The elevated portion  58  creates a space  64  above the PCB  42 . The latches  26  fit snugly on opposite sides of the latch cover  52  and define a space  98  therebetween. In the illustrated embodiment, the latch cover  52  is secured to the top cover  12  by fasteners (not shown) that extend through a plurality of fastening holes  66 . However, in further embodiments the latch cover  52  may be secured to the internal frame  44 . Together, the main portion  56  and the elevated portion  58  protect the PCB  42  by redirecting water between the internal frame  44  and the second portion  16  of the housing  12  towards the bottom cover  38  where it is expelled through the holes  94 ,  96  of the second portion  16  and bottom cover  38 . 
         [0037]      FIGS. 14-18  illustrate the terminal cover  50 . The terminal cover  50  includes a first portion  72 , which rests on the distal end  48  of the PCB  42 , and a second portion  74  that extends below the distal end  48  of the PCB  42 , which rests on the upper portion  60  of the internal frame  44 . The terminal cover also includes a tooth  108  ( FIG. 17 ) on each side of terminal cover  50 , which rests on a projection  106  of the internal frame  44 . The terminal cover  50  includes a projection  76 , which also rests against the PCB  42 . The terminal cover  50  further includes openings  68  having channels  70  on a distal end  100  of the terminal cover  50 . The terminals  36  are received within the openings  68  such that portions  102  of the terminals  36  abut the terminal cover  50  at the distal end  100  thereby preventing water from entering the battery pack  10 . The channels  70  assist in aligning the female terminals  36  of the battery pack  10  and the male terminals of the power tool (not shown). Further, in the event that water should enter between the first portion  14  of the housing  12  and the terminals  36 , there is a gap  104  between the distal end  48  of the PCB  42  and the terminal cover  50  that prevents water from reaching the PCB  42 . The projection  106  of the internal frame  44  is located below gap  104  so that water falls through the gap  104  and is redirected towards bottom of battery pack  10  and through the holes  94 ,  96  of the second portion  16  and bottom cover  38  via the channels  92  of the internal frame  44 . Because the terminals  36  have various sizes and the openings  68  are sized to accommodate the terminals  36 , the openings  68  may have different dimensions. For example, the terminal cover  50  has a first length  78  and a second length  80  associated with different terminal blade sizes of the terminals  36 . 
         [0038]      FIGS. 22-33  illustrate a battery pack  100  according to another embodiment of the invention. The battery pack  100  of  FIGS. 22-33  is similar to the battery pack  10  of  FIGS. 1-9 ; therefore, like structures will be identified by like references numbers plus “100” and only the differences will be discussed hereafter. 
         [0039]    The battery pack  100  includes a housing or case  112  having a first portion  114  (i.e., a top housing) and a second portion  116  (i.e., a bottom housing), which are coupled along a longitudinal axis A. The two portions  114 ,  116  of the housing  112  are coupled, for example, by fasteners (not shown) that extend through a plurality of complementary fastening holes  118 . An interface  120  of the first portion  114  is able to be physically coupled to the base or other battery receiving portion of a power tool (not shown). 
         [0040]    With reference to  FIGS. 23-26 , the second portion  116  of the housing includes body  202  having a bottom wall  204  integrally formed with four side walls  206 - 212  creating a cavity  214  therein. The cavity  214  receives an internal frame  144  that together with a plurality of wedges  86  secures batteries  46  within the battery pack  100  ( FIGS. 31 and 32 ). The battery pack  100  includes an outer surface  216  and an inner surface  218 . The outer surface  216  of the bottom wall  204  that includes a reinforced area  220  having ridge  222  that defines a substantially rectangularly shaped area and one chamfered corner  224 . The outer surface  216  of the second portion  116  includes a step or ridge  226  that is intermediate between the bottom wall  204  and a top edge  228  and extends along sidewalls  206 - 212 . The outer surface  216  additionally includes recessed portions  230 . The second portion  116  includes a plurality of openings or holes  196  that extend from the bottom wall  204  to each of the side walls  206 - 212 ; the holes  196  are located within the recessed portions  230  of the exterior surfaces  216 . The bottom wall  204  includes a plurality of apertures  200 . The holes  196  and apertures  200  extend from the outer surface  216  of the battery pack  100  to the inner surface  218 . The holes  196  and the apertures  200  are offset relative to one another. The holes  196  and apertures  200  may be created by extrusion or any other suitable manufacturing process. In the illustrated embodiment, there are eight holes  196  and six apertures  200 ; further embodiments may include fewer or more holes  196  and apertures  200 . 
         [0041]    The battery pack  100  also includes a bottom cover or overmold  138  illustrated in  FIGS. 22-24  and  27 - 28 . The bottom cover  138  includes a body  302  having a bottom wall  304  integrally formed with four side walls  306 - 312  creating a cavity  314  therein. An upper boundary of the cavity  314  is defined by an edge  316  created by the four side walls  306 - 312 . The bottom wall  304  defines a rectangular opening or cutout  305 . The bottom cover  138  has an outer surface  318  and an inner surface  320 . The outer surface  318  includes a plurality of recessed areas  322  that correspond to a plurality of projections  324  on the inner surface  320  of the bottom cover  138 . The bottom cover  138  accommodates the insertion and removal of fasteners (not shown) via two through-holes  326  on a first end  328  and two recesses  330  on a second end  332 . The bottom cover  138  also includes a plurality of holes or openings  194  that extend from the bottom wall  304  to the side walls  306 - 312 . The holes  194  are located within the recessed areas  322  of the bottom cover  138 . The bottom cover  138  additionally includes a plurality of bumpers or projections  334  that are integrally formed with the inner surface  320 . In the illustrated embodiment, the bottom cover includes six holes  194  and six bumpers  334 . Further embodiments may include more or less holes and bumpers. 
         [0042]      FIGS. 22-24  and  28 - 32  illustrate that, when assembled, the bottom cover  138  overlays the second portion  116  of the battery pack  100 . As such, an interface  350  is created at the top edge  316  of the bottom cover  138 , which compliments and aligns with the step  226  in the second portion  116  of the battery pack  100 . The bumpers  334  of the bottom cover  138  extend through the apertures  200  in the second portion  116 , which further ensures the proper alignment of the bottom cover  138  with respect to the second portion  116 . In the embodiments illustrated in  FIGS. 30 and 31 , the internal frame  144  sits on the bumpers  334 . Alternatively,  FIG. 33  illustrates another embodiment that includes a first frame member  444  and a second frame member  446  that, together, support a single row of batteries  46 . The second frame member  446  includes apertures  448  that receive bumpers  334  in the bottom cover  138 . In the embodiment illustrated in  FIG. 33 , an aperture  448  and bumper  334  are associated with each battery  46 ; in alternate embodiments, the number of bumpers and apertures do not equal the number of batteries housed within the battery pack  100 . In either embodiment, the bumpers  334  take up tolerance between the internal frame  144 ,  446  and the second portion  116  of the battery pack  100 , and also function as shock-absorbers if the pack  100  is dropped or under conditions of high vibration. Additionally, the bottom cover  138  improves the user&#39;s grip, for instance, when inserting the battery pack and removing the battery pack into and from the power tool. The bottom cover  138  also prevents the battery pack from sliding across surfaces. When the bottom cover  138  overlays the second portion  116  of the battery pack  100 , the holes  194  in the bottom cover  138  are aligned with holes or openings  196  in the second portion  116  of the housing  112 . The bottom holes  194 ,  196  are drain holes that allow any water that infiltrates the cavity  214  to exit the housing  112  rather than pooling inside the cavity  214 . The rectangular cutout  305  in the bottom cover  137  receives the reinforced area  220  in the bottom wall  204  of the second portion  116  of the battery pack  100 . The recesses  230  in the outer surface  216  of the second portion  116  correspond to the projections  324  along the inner surface  320  of the bottom cover. In this way, the contours of the second portion  116  and the bottom cover  138  are complimentary. In embodiment of  FIGS. 22-24  and  28 - 32 , the number of holes  194  in the bottom cover  138  corresponds to the number holes  196  in the second portion  116 . Similarly, the number of bumpers  334  corresponds to the number of apertures  200  in the second portion  116 . In further embodiments, there may not be a 1:1 relationship between these components. 
         [0043]    In the illustrated embodiments, the housing  12 ,  112  of the battery packs  10 ,  100  as well as the bottom covers  38 ,  138  are constructed from plastic. Further embodiments the housing and covers may be constructed from any suitable material. 
         [0044]    Thus, the invention provides, among other things, a battery pack including water infiltration protection via a latch and terminal cover, which direct water away from a PCB to a bottom of the battery case housing. Further, the invention provides an internal frame for securing a plurality of batteries and constructed from a single piece. Additionally, the invention provides wedges that also participate in securing the batteries and allow the use of different size batteries, as well. The battery pack also includes an overmold that participates in shock-absorption, prevents the battery pack from sliding, and improves the users grip when inserting and removing the battery pack into and from the power tool. Various features and advantages of the invention are set forth in the following claims.