Patent Publication Number: US-2010129701-A1

Title: Battery packs

Description:
This application claims priority to Japanese patent application serial number 2008-299319, the contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to battery packs that are used, for example, as power sources of portable power tools. 
     2. Description of the Related Art 
     In general, a battery pack of a power tool can be removed from a tool body and recharged in order to repeatedly use the battery pack. For example, in known portable power screwdrivers, such as those disclosed in EP1128517A2 and Japanese Laid-Open Patent Publication No. 2001-238362, a battery pack is slidably mounted to and removed from a battery mounting portion provided at a leading end of a handle portion that extends laterally from a tool body. When the battery pack is slidably moved by an operator so as to be mounted to the battery mounting portion, the battery pack is electrically connected to a power source circuit of the tool body. On the other hand, when the battery pack is slidably moved in a removing direction, the battery pack is removed from the battery mounting portion and is electrically disconnected from the power source circuit. The removed battery can be slidably mounted to a mounting portion of a battery charger that can recharge the battery. 
     In the case that the battery pack is small and lightweight, the battery pack can be easily handled and the mounting and removing operations of the battery pack can be made without difficulties. However, in recent years, battery packs having large outputs (such as 36V) have been used Because, these battery packs are large in size and heavy, the handling of the battery packs cannot be easily made. 
     Therefore, there is a need in the art for enabling a battery pack to be easily removed from a tool body of a power tool. 
     SUMMARY OF THE INVENTION 
     One aspect according to the present invention includes a battery pack having a battery pack body. The battery pack body includes a finger engaging portion engageable with a finger or fingers of an operator in a removing direction of the battery pack body from a power tool. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a power tool and a battery pack according to an embodiment of the present invention and showing a mounted state of the battery pack to the power tool; 
         FIG. 2  is a perspective view of the battery pack; 
         FIG. 3  is a plan view of the battery pack as viewed in a direction indicated by an arrow (III) in  FIG. 2 ; 
         FIG. 4  is a perspective view of the battery pack as viewed in a direction indicated by an arrow (N) in  FIG. 2 ; 
         FIG. 5  is a perspective view of the battery pack and showing the state where a lock button is pressed down by an index finger of an operator; and 
         FIG. 6  is a perspective view of the battery pack and showing the state where the lock button is pressed downwardly by a thumb of an operator. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Each of the additional features and teachings disclosed above and below may be utilized separately or in conjunction with other features and teachings to provide improved battery packs and power tools incorporating the battery packs. Representative examples of the present invention, which examples utilize many of these additional features and teachings both separately and in conjunction with one another, will now be described in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Only the claims define the scope of the claimed invention. Therefore, combinations of features and steps disclosed in the following detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Moreover, various features of the representative examples and the dependent claims may be combined in ways that are not specifically enumerated in order to provide additional useful embodiments of the present teachings. 
     In one embodiment, a battery pack for a power tool includes a battery pack body capable of being removed from the power tool in a removing direction. The battery pack body includes a finger engaging portion engageable with a finger or fingers of an operator in the removing direction of the battery pack body. 
     With this arrangement, the finger engaging portion can serve as a slip preventing portion when the operator engages the finger engaging portion with his or her finger(s) for removing the battery pack from the power tool. Therefore, the battery pack can be easily removed from the power tool even in the case that the battery pack has a large size and a heavy weight. Hence, handling of the battery pack can be facilitated. 
     The battery pack may further include a lock device and an operation member. The lock device is capable of releasably locking the battery pack body against the power tool. The operation member is operable for unlocking the lock device. The battery pack body may further include left and right and second side portions disposed on opposite sides with respect to the operation member and a bottom side portion extending substantially perpendicular to the left and right side portions. At least one of the left, right and bottom side portions includes the finger engaging portion. 
     For example, in the case that the operator operates the operation member with his or her thumb, the finger engaging portion may be provided on the bottom side portion for engagement by the other finger(s) other than the thumb. In the case that the operator operates the operation member with his or her index finger, the finger engaging portion may be provided on each of the left and right side portions for engagement by the other finger(s) than the index finger. The finger engaging portion may be provided in each of the bottom side portion and the left and right side portions, so that the operator can operate the operation member with either the thumb or the index finger. 
     The finger engaging portion may include a linear projection disposed on the battery pack body and extending in a direction intersecting with the removing direction. Alternatively, the finger engaging portion may include a linear recess formed in the battery pack body and extending in a direction intersecting with the removing direction. Because the projection or the recess may have a long length in a direction intersecting with the removing direction, it is possible to ensure a large engageable range of the finger engaging portion for engagement with the finger(s). Therefore, handling of the battery pack can be further facilitated. 
     The battery pack body may further include a front side portion extending substantially perpendicular to the left, right and bottom side portions. Left and right corner portions may be defined between the front side portion and the left and right side portions, respectively. The finger engaging portion may include a left finger engaging portion disposed on the left side portion and a right finger engaging portion disposed on the right side portion. The left finger engaging portion extends along the left corner portion. The right finger engaging portion extends along the right corner portion. 
     With this arrangement, in the case that the operator operates the operation member that may be a lock button, the operator can position his or her index finger at the operation member and easily extend the other fingers than the index finger to the left and right engaging portions for engaging them in order to pinch the battery pack body from left and right sides. Therefore, handling of the battery pack can be further facilitated. 
     In the case that the finger engaging portion includes the bottom finger engaging portion disposed on the bottom side portion, the battery pack body may further include a protrusion disposed on the bottom side portion and capable of compensating inclination of the battery pack relative to a surface on which the battery pack is placed. 
     With this arrangement, when the battery pack is placed on a surface, such as a surface of a workbench on which the battery pack is placed, it is possible to position the battery pack such that the battery pack is oriented horizontally parallel to the surface without being inclined relative thereto. In addition, the power tool having the battery pack mounted thereto can be positioned in stable on the surface by positioning the power tool such that the bottom of the battery pack contacts the surface. 
     An embodiment of the present invention will now be described with reference to the drawings. Referring to  FIG. 1 , a power tool  1  incorporating a battery pack  10  according to the embodiment is shown. In this embodiment, the power tool  1  is configured as a hammer drill that can be used for boring, chipping and crushing of a concrete structure. The power tool  1  has a tool body  2  and a handle  3 . Within the tool body  2 , an electric motor (not shown) is disposed to extend vertically, so that its rotational axis extends vertically. The rotation of the electric motor is reduced by a reduction gear mechanism (not shown) and is thereafter transmitted from an output shaft of the reduction gear mechanism to a spindle  4 . The output shaft of the reduction gear mechanism extends in a direction perpendicular to the rotational axis of the motor. 
     The handle  3  has a substantially loop-shaped configuration and is formed integrally with a rear portion of the tool body  2 . A switch lever or a trigger  5  is disposed on an inner circumference of the handle  3  and can be operated by a finger or fingers of the operator in order to start the motor. An auxiliary handle  6  extends downward from a front portion of the tool body  2 . Therefore, the operator can firmly hold the power tool  1 , for example, by grasping the handle  3  with his or her right hand and grasping the auxiliary handle  6  with his or her left hand. 
     The battery pack  10  is mounted to a lower portion of the handle  3 . The battery pack  10  may be a lithium ion battery having a rating voltage of 36V and can be repeatedly used by being recharged. The motor receives a supply of power from the battery pack  10 . More specifically, the battery pack  10  has a battery pack body  10 A and can be mounted to a battery mounting portion  3   a  of the handle  3  by sliding the battery pack body  10 A forwardly relative to the battery mounting portion  3   a.  The battery pack  10  can be removed from the battery mounting portion  3   a  by sliding the battery pack body  10 A rearwardly relative to the battery mounting portion  3   a.  The battery pack  10  in the state of being removed from the battery mounting portion  3   a  is shown in  FIGS. 2 to 6 . 
     The battery pack body  10 A has a substantially hexahedron block-like configuration. A plurality of battery cells (not shown) are disposed within the battery pack body  10 A. Left and right guide rails  11 L and  11 R are provided on a surface of an upper portion  10 U of the battery pack body  10 A and can engage left and right guide recesses (not shown) formed in the battery mounting portion  3   a,  respectively. The left and right guide rails  11 L and  11 R may be formed integrally with the surface of the upper portion  10 U. The left and right guide recesses extend in forward and rearward directions. Therefore, the battery pack body  10 A can slide in forward and rearward directions relative to the battery mounting portion  3   a.  When the battery pack body  10 A is slid rearward, the battery pack  10  can be mounted to the battery mounting portion  3   a.  A positive connecting terminal  18  and a negative connecting terminal  19  are mounted to the upper portion  10 U and are positioned between the left and right guide rails  11 L and  11 R. When the battery pack  10  is mounted to the battery mounting portion  3   a  of the power tool  1 , the connecting terminals  18  and  19  are electrically connected to a power source circuit (not shown) of the tool body  2 . 
     An operation member  12  is movably supported within a front side portion  10 F of the battery pack body  10 A and can be pressed downward by a finger or fingers of the operator for removing the battery pack  10 . In this embodiment, the operation member  12  is configured as a lock button. The operation member  12  is positioned at an upper part of the front side portion  10 F, and more specifically, at a central portion with respect to right and left directions of the upper part. A lock member  13  is coupled to the operation member  12  and extends vertically through the upper portion  10 U. When the operation member  12  is pressed downward, the lock member  13  also moves downward. In this embodiment, the lock member  13  is configured as a claw. The operation member  12  is biased upward by a spring (not shown). Therefore, when the pressing force applied by the fingertips) of the operator is released, the operation member  12  returns upward by the biasing force of the spring. Because the operation member  12  is biased upward, the lock member  13  is also biased upward toward an engaging position. The battery mounting portion  3   a  has an engaging portion for engaging the lock member  13 . When the battery pack  10  is mounted to the battery mounting portion  3   a  of the handle  3 , the lock member  13  can engage the engaging portion, so that the battery pack body  10 A is locked not to move in forward and rearward directions. 
     When the operation member  12  is pressed downwardly by a finger(s), such as a thumb and an index finger, the lock member  13  moves downward together with the operation member  12  so as to be disengaged from the engaging portion. Then, the battery pack  10  can be moved in the removing direction for removing the battery pack  10  from the battery mounting portion  3   a.    
     In order to facilitate the removing operation of the battery pack  10 , the battery pack body  10 A of the battery pack  10  has finger engaging portions  14 ,  15  and  16 . As shown in  FIG. 3 , the finger engaging portions  14  and  15  are provided in left and right pairs and extend along corner portions of the battery pack body  10 A. The corner portions are positioned on the front sides of left and right side portions  10 L and  10 R and are defined between the front side portion  10 F and the left and right side portions  10 L and  10 R, respectively. The finger engaging portions  14  and  15  project laterally outward from the corner portions. More specifically, each of the finger engaging portions  14  and  15  is configured as a linear projection extending in a vertical direction intersecting with or perpendicular to the removing direction (forward direction) of the battery pack  10 . The finger engaging portion  14  has a substantially triangular cross sectional configuration along the entire vertical length of the left side portion  10 L. Similarly, the finger engaging portion  15  has a substantially triangular cross sectional configuration along the entire vertical length of the right side portion  10 R. In this embodiment, the finger engaging portions  14  and  15  are formed integrally with the left and right side portions  10 L and  10 R, respectively. In other words, the finger engaging portions  14  and  15  are formed integrally with the battery pack body  10 A. However, the finger engaging portions  14  and  15  may be formed as separate members from the battery pack body  10 A and may be attached to the battery pack body  10 A. 
     As shown in  FIG. 5 , the left and right finger engaging portions  14  and  15  can be used when the operator presses the operation member  12  with his or her index finger. Thus, for example, the operator may position the index finger of his or her right hand at the operation member  12 , engage the thumb of the same hand with the left finger engaging portion  14  of the left side portion  10 L, and engage the middle finger or the medicinal finger with the finger engaging portion  15  of the right finger engaging portion  10 R, so that the operator can pinch or hold the battery pack body  10 A from left and right sides. By pressing the operation member  12  with the index finger while the left and right finger engaging portions  14  and  15  being engaged by the thumb and the middle finger (or the medicinal finger) in this way, the lock member  13  is disengaged from the claw engaging portion of the tool body  2 . As a result, the battery pack  10  can be removed from the battery mounting portion  3   a  by forwardly slidably moving the battery pack body  10 A. 
     In the case that the operator holds the battery pack  10  with his or her left hand, the operator may position the index finger of his or her left hand at the operation member  12 , engage the thumb of the same hand with the right finger engaging portion  15  of the right side portion  10 R, and engage the middle finger or the medicinal finger with the finger engaging portion  14  of the left finger engaging portion  10 L, so that the operator can pinch or hold the battery pack body  10 A of the battery pack  10  from left and right sides. 
     As shown in  FIG. 4 , the finger engaging portion  16  is disposed at a bottom side portion  10 B of the battery pack body  10 A. More specifically, the finger engaging portion  16  is positioned at a front part of the bottom side portion  10 B. The finger engaging portion  16  is configured as a linear projection extending in a horizontal direction (left and right directions) that is a direction intersecting with or perpendicular to the removing direction (forward direction) of the battery pack  10 . In this embodiment, the finger engaging portion  16  is formed integrally with the bottom side portion  10 B. However, the finger engaging portion  16  may be formed as a separated member from the bottom side portion  10 B and may be attached to the bottom side portion  10 B. 
     As shown in  FIG. 6 , the finger engaging portion  16  can be used when the operator presses down the operation member  12  with the thumb of his or her right hand. In this case, the thumb is positioned at the operation member  12  and the index finger (and/or middle finger and/or the medicinal finger) of the same hand is engaged with the finger engaging portion  16 , so that the battery pack body  10 A can be held from its upper and lower sides. Although not shown in the drawings, it is possible to hold the battery pack body  10 A with his or her left hand in the same manner as described in connection with the right hand. 
     By pressing down the operation member  12  with the thumb while the index finger (and/or middle finger and/or the medicinal finger) of the same hand being engaged with the finger engaging portion  16 , the lock member  13  is disengaged from the engaging portion of the tool body  2 . As a result, the battery pack  10  can be removed from the battery mounting portion  3   a  by forwardly slidably moving the battery pack body  10 A. 
     At the bottom side portion  10 B of the battery pack body  10 A, a protrusion  17  is disposed for preventing inclination of the battery pack  10 . The protrusion  17  protrudes from the bottom side portion  10 B by the same distance as the finger engaging portion  16  and linearly extends in the horizontal direction (right and left directions). Therefore, it is possible to prevent the battery pack  10  from inclining from the horizontal direction when the battery pack  10  is placed, for example, on a surface of a workbench. In this embodiment, the protrusion  17  is formed integrally with the bottom side portion  10 B. However, the protrusion  17  may be formed as a separate member from the bottom side portion  10 B and may be attached to the bottom side portion  10 B. 
     According to the battery pack  10  constructed as described above, the finger engaging portions  14  and  15  are disposed at the left and right side portions  10 L, and  10 R, respectively, and the finger engaging portion  16  is disposed at the bottom side portion  10 B. The finger engaging portions  14 ,  15  and  16  can serve as slip preventing devices when they are engaged by fingers of the operator. Therefore, the battery pack  10  can be easily mounted to and removed from the battery mounting portion  3   a  of the power tool  1  even in the case that the battery pack  10  is large and heavy due to its large capacity (36V). Therefore, the battery pack  10  can be easily handled. 
     In addition, because the protrusion  17  is disposed at the bottom side portion  10 B of the battery pack body  10 A to correspond to the finger engaging portion  16 , the battery pack  10  can be placed horizontally on a surface of a workbench after it has been removed from the power tool  1 . Further, in the mounted state of the battery pack  10  to the power tool  1  (more specifically, the battery mounting portion  3   a  of the handle  3  of the tool body  2 ), the power tool  1  can be positioned in stable on a workbench when the power tool  1  is placed on the workbench with the bottom side portion  10 B of the battery pack body  10 A opposed to and contacting with the surface of the workbench. This is because the battery pack  10  can be placed horizontally on the surface of the workbench. 
     The above embodiment can be modified in various ways. For example, although three finger engaging portions  14 ,  15  and  16  are provided, only the finger engaging portion  16  of the bottom side portion  10 B may be provided by omitting the finger engaging portions  14  and  15  of the left and right side portions  10 L and  10 R. Alternatively, only the finger engaging portions  14  and  15  may be provided by omitting the finger engaging portion  16 . 
     Furthermore, although the finger engaging portions  14  and  15  are positioned at the front parts of the left and right side portions  10 L and  10 R and adjacent the front corner portions of the battery pack body  10 A, respectively, they may be positioned at the middle positions with respect to the left and right directions of the left and right side portions  10 L and  10 R, respectively. A plurality of finger engaging portions  14  may be disposed at the left side portion  10 L and/or a plurality of finger engaging portions  15  may be disposed at the right side portion  10 R and/or a plurality of finger engaging portions  16  may be disposed at the bottom side portion  10 B. 
     Furthermore, although the finger engaging portions  14  and  15  are configured as linear projections extending in the vertical direction of the left and right side portions  10 L and  10 R, each of the finger engaging portions  14  and  15  may be configured as a recess or a plurality of parallel recesses extending in the vertical direction for engaging with fingers of the operator. Similarly, the finger engaging portion  16  may be configured as a recess or a plurality of parallel recesses extending in the horizontal direction (right and left directions) of the bottom side portion  10 B.