Patent Publication Number: US-2023147667-A1

Title: Hand-Held Power Tool comprising a Rechargeable Battery Pack Interface

Description:
This application claims priority under 35 U.S.C. § 119 to patent application no. DE 10 2021 212 585.9, filed on Nov. 9, 2021 in Germany, the disclosure of which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     The present disclosure relates to a hand-held power tool comprising a housing in which at least one drive motor for driving a tool holder is disposed and comprising a rechargeable battery pack interface for placing a rechargeable battery pack for supplying power to the drive motor, wherein the rechargeable battery pack interface forms a primary support for the rechargeable battery pack. 
     Such a rechargeable battery-operated hand-held power tool comprising a rechargeable battery pack interface for placing a rechargeable battery pack is known from the prior art. The rechargeable battery pack interface forms a primary support, which supports the rechargeable battery pack in the event of a shock pulse to the rechargeable battery pack, e.g., as a result of accidental dropping of the hand-held power tool. 
     SUMMARY 
     The disclosure relates to a hand-held power tool comprising a housing in which at least one drive motor for driving a tool holder is disposed and comprising a rechargeable battery pack interface for placing a rechargeable battery pack for supplying power to the drive motor, wherein the rechargeable battery pack interface forms a primary support for the rechargeable battery pack. At least two intermediate elements for forming a secondary support are disposed on the housing in the region of the rechargeable battery pack interface, wherein the at least two intermediate elements are disposed in such a way that a specified distance between the at least two intermediate elements and a rechargeable battery pack disposed at the rechargeable battery pack interface is provided which decreases in the direction of the at least two intermediate elements in the event of a shock pulse to the rechargeable battery pack and forms the secondary support when the rechargeable battery pack abuts the at least two intermediate elements. 
     The disclosure thus makes it possible to provide a hand-held power tool in which the at least two intermediate elements can provide a secondary support for the rechargeable battery pack for additional support for the rechargeable battery pack, e.g., in the event of accidental dropping of the hand-held power tool from a height of in particular more than one meter. 
     The rechargeable battery pack interface is preferably associated with a spring-decoupled contact holder to maintain electrical contact of the rechargeable battery pack at the rechargeable battery pack interface in the event of a shock pulse to the rechargeable battery pack in the direction of the at least two intermediate elements as the rechargeable battery pack moves from its mechanical receptacle into the primary and secondary support. 
     Destruction of the hand-held power tool by overstressing the rechargeable battery pack interface as a result of accidental dropping, e.g., from a height of in particular more than one meter, can thus reliably be prevented in an uncomplicated manner. The primary support is provided at the spring-decoupled contact holder and the secondary support is provided via the at least two intermediate elements at which any kinetic energy or impact energy is redirected. 
     The specified distance is preferably 2.5 mm ± 1 mm. 
     A suitable distance between the intermediate element and the rechargeable battery pack to implement a gradual redirection of force for the primary and secondary support can thus be provided in a simple manner. 
     The at least two intermediate elements preferably comprise polyurethane. 
     Thus, a suitable material which has good abrasion resistance can be provided in a simple and uncomplicated manner for the at least two intermediate elements. 
     The at least two intermediate elements preferably have a thickness between 2 mm and 8 mm. The at least two intermediate elements preferably each have a Shore Hardness between 60 and 70 Shore. 
     The at least two intermediate elements can thus be configured to be elastic but not damping, which enables the redirection of impact energy. A comparatively large abutment surface between the lateral surfaces can furthermore be achieved as well, as a result of which unevennesses can easily be compensated. 
     According to one embodiment, the at least two intermediate elements are attached to the housing via an adhesive connection. 
     The at least two intermediate elements can thus easily be attached to the housing after completion of the hand-held power tool, or as a retrofit to an existing hand-held power tool. 
     The at least two intermediate elements are preferably detachably disposed on the housing. 
     Therefore, if required, the at least two intermediate elements can be replaced in a simple and uncomplicated manner. 
     The housing preferably comprises a housing portion on which the at least two intermediate elements are disposed, wherein the housing portion is disposed at a specified angle to the rechargeable battery pack interface. 
     A suitable arrangement of the at least two intermediate elements in the region of the rechargeable battery pack interface to form the secondary support can thus easily be made possible. 
     When the rechargeable battery pack is installed at the rechargeable battery pack interface, the housing portion preferably comprises a lateral surface which is disposed such that it faces the rechargeable battery pack and the rechargeable battery pack comprises a lateral surface which is disposed such that it faces the housing portion and the specified distance is provided between the two lateral surfaces. 
     The specified distance for implementing a gradual redirection of force for the primary and secondary support can thus be provided in a simple and uncomplicated manner. 
     According to one embodiment, electronics of the hand-held power tool are disposed in the housing portion. 
     This enables reliable operation of the hand-held power tool, because the at least two intermediate elements can redirect impact energy that would otherwise act on the electronics in the event of accidental dropping of the hand-held power tool. 
     The housing portion is preferably comprised two housing half-shells and at least one intermediate element is attached to each housing half-shell. 
     Easy installation of the electronics and wiring associated with the electronics can thus be ensured in a simple manner. The at least two intermediate elements can furthermore be installed in the course of a preassembly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure is explained in more detail in the following description with reference to design examples which are shown in the following drawings. 
         FIG.  1    is a side view of a hand-held power tool comprising a rechargeable battery pack and intermediate elements associated with the rechargeable battery pack in an impact on a first edge of the rechargeable battery pack, 
         FIG.  2    is a side view of the hand-held power tool comprising a rechargeable battery pack of  FIG.  1    in an impact on a second edge of the rechargeable battery pack, 
         FIG.  3    is an enlarged view of a rechargeable battery pack interface associated with the hand-held power tool of  FIG.  1    and  FIG.  2    with the housing of the hand-held power tool open, and 
         FIG.  4    is a perspective view of a housing portion associated with the housing of the hand-held power tool of  FIG.  1    to  FIG.  3    with the intermediate elements. 
     
    
    
     DETAILED DESCRIPTION 
     Elements having the same or a comparable function are provided with the same reference signs in the figures and are described in detail only once. 
       FIG.  1    shows an example of a hand-held power tool  100  comprising a housing  110 , in which a drive unit for rotatably driving a tool holder  130  is preferably disposed. As can be seen, the tool holder  130  is illustratively configured to receive an insert tool and, in operation, rotates about an associated axis of rotation. An optional auxiliary handle  119  is furthermore disposed on the housing  110  in the region of the tool holder  130 . 
     The drive unit in the shown design example illustratively comprises at least one drive motor  125  and a gearing  120 . The drive motor  125  is preferably configured as an electronically commutated motor. The drive motor  125  can preferably be switched on and off via a manual switch  117 , wherein the manual switch  117  is illustratively disposed on a handle  115  of the housing  110 . 
     The hand-held power tool  100  furthermore preferably comprises a rechargeable battery pack interface  160  for placing a rechargeable battery pack  190  for supplying power to the drive motor  125 . For this purpose, the rechargeable battery pack interface  160  illustratively comprises at least one, preferably two guide rails  162 . The rechargeable battery pack  190  analogously likewise comprises at least one, preferably two guide rails  192 . The rechargeable battery pack  190  is preferably disposed at the rechargeable battery pack interface  160  by sliding (in  FIG.  1    illustratively from right to left). The guide rails  192  of the rechargeable battery pack  190  are thereby guided on the guide rails  162  of the hand-held power tool  100  or the rechargeable battery pack interface  160  of the hand-held power tool  100 . 
     In the region of the guide rail  192 , the rechargeable battery pack  190  preferably comprises a locking element  194 . The rechargeable battery pack  190  furthermore comprises an (illustratively in  FIG.  1   ) right and an (illustratively in  FIG.  1   ) left lateral surface  193 ,  191  and two edges  195 ,  196 . The edge  195  is illustratively disposed between the lateral surface  193  and a bottom surface  197  and the edge  196  is disposed between the lateral surface  191  and the bottom surface  197 . 
     The housing  110  preferably comprises a housing portion  150 . The housing portion  150  is disposed at a specified angle to the rechargeable battery pack interface  160 . Illustratively, the specified angle is approximately 90 degrees. Electronics  154  of the hand-held power tool  100  are preferably disposed in the housing portion  150 . According to one embodiment, at least the housing portion  150  is configured of two housing half-shells  151 . 
     In the installed state of the rechargeable battery pack  190  at the rechargeable battery pack interface  160  shown in  FIG.  1   , the housing portion  150  comprises a lateral surface  152  which is disposed such that it faces the rechargeable battery pack  190 . The lateral surface  191  of the rechargeable battery pack  190  is analogously disposed such that it faces the housing portion  150 . 
     The rechargeable battery pack interface  160  preferably forms an electromechanical receptacle and guide for the rechargeable battery pack  190 , wherein a stop in the guide rail  162  forms a primary support. On the one hand, the primary support forms a support for the rechargeable battery pack  190 , e.g., in an impact of the rechargeable battery pack  190  fixed to the rechargeable battery pack interface  160  onto a surface as a result of in particular accidental dropping of the hand-held power tool  100  from a height of in particular more than one meter, and, on the other hand, it forms an arrangement of the rechargeable battery pack  190  in its disposed, in particular inserted, state at the rechargeable battery pack interface  160  during a working process. According to one embodiment, a spring-decoupled contact holder  165  is associated with the rechargeable battery pack interface  160  for this purpose. Such a spring-decoupled contact holder  165  is known from DE 10 2005 020 358 A1, which is hereby explicitly included in the present patent application. In the event of a shock pulse to the rechargeable battery pack  190  caused by the above-described impact on a surface as a result of dropping from a height of more than 1 m, the electrical contact between the rechargeable battery pack  190  and the contact holder  165  is maintained by the spring decoupling on the contact holder  165 . Such a shock pulse can result from a fall of the hand-held power tool  100  and a corresponding impact to the rechargeable battery pack  190 , for instance, or from a blow to the rechargeable battery pack  190  or the like. 
     According to the disclosure, at least two intermediate elements  170  for forming a secondary support are disposed on the housing  110  in the region of the rechargeable battery pack interface  160 . The at least two intermediate elements  170  are preferably disposed such that, in an unloaded state, e.g., during a working process in which the rechargeable battery pack  190  is not subjected to a force, a specified distance ( 301  in  FIG.  3   ) is formed between the at least two intermediate elements  170  and a rechargeable battery pack  190  disposed at the rechargeable battery pack interface  160 . 
     The at least two intermediate elements  170  are preferably disposed on the housing portion  150 , in particular on the lateral surface  152  of the housing portion  150 . According to one embodiment, at least the housing portion  150  is configured of two housing half-shells  151 , wherein at least one intermediate element  170  is attached to each housing half-shell  151 . 
     The specified distance ( 301  in  FIG.  3   ) is preferably formed between the lateral surface  152  of the housing portion  150  and the lateral surface  191  of the rechargeable battery pack  190  which is disposed such that it faces the housing portion  150 . The specified distance ( 301  in  FIG.  3   ) preferably decreases in the event of a shock pulse to the rechargeable battery pack  190 , e.g., the above-described impact on a surface as a result of accidental dropping from a height of in particular more than one meter, in the direction of the at least two intermediate elements  170 . The secondary support is formed when the rechargeable battery pack  190  abuts the at least two intermediate elements  170 . 
     The spring-decoupled contact holder  165  is in particular configured to maintain electrical contact of the rechargeable battery pack  190  at the rechargeable battery pack interface  160  in the event of a shock pulse to the rechargeable battery pack  190  as the rechargeable battery pack  190  moves from its mechanical receptacle into the primary and secondary support. 
     The at least two intermediate elements  170  preferably comprise polyurethane. Polyurethane provides good abrasion resistance and leaves no signs of wear when two components come into contact. The at least two intermediate elements  170  preferably have a thickness (403 in  FIG.  4   ) between 2 mm and 8 mm. This preferably does not result in any damping, but merely in a redirection of impact energy. The at least two intermediate elements  170  furthermore preferably each have a Shore Hardness between 60 and 70 Shore. 
     According to one embodiment, the at least two intermediate elements  170  are attached to the housing  110  via an adhesive connection. The housing portions  150  preferably comprise an adhesive surface on their lateral surfaces  152 . The at least two intermediate elements  170  are preferably detachably disposed on the housing  110 . 
     When the hand-held power tool  100  falls from a height of in particular more than one meter and the hand-held power tool  100  impacts on the rechargeable battery pack  190  or on the edge  195 , there is a weak point  105  in the region of the rechargeable battery pack interface  160 . The weak point  105  is preferably located at the mechanical stop of the guide rails  162 , illustratively at the right end thereof. An occurring kinetic energy or an impact energy is indicated with the arrows  101 ,  102 . The impact energy is transmitted along the arrow  102  from the guide rail  192  to the guide rail  162  until the primary support comes into contact at the weak point  105 . Elastic deformations occur at the weak point  105  and the specified distance ( 301  in  FIG.  3   ) simultaneously decreases. The remaining impact energy is then passed on along the arrow  101  to the at least two intermediate elements  170  and directed into the housing portion  150 . This process therefore acts in a progressive manner. Destruction at the weak point  105  of the guide rails  162  and the guide of the rechargeable battery pack  192  is thus prevented, because the impact energy is gradually distributed between the primary support and the secondary support on the housing portion  150 . Redirection of the impact energy acting on the housing portion  150  preferably takes place at a sufficiently rigid lateral surface  152  of the housing portion  150 , to which the at least two intermediate elements  170  are preferably glued. The electronics  154  are preferably fixed in the housing portion  150  at their own attachment points inside the housing portion  150 . This results in a sufficiently large buffer zone between the lateral surface  152  and the electronics  154 . The electronics  154  are protected from the redistribution of forces on the housing portion  150  by the buffer zone. 
     As an example, the hand-held power tool  100  is configured in  FIG.  1    as a drill driver. However, the hand-held power tool  100  can also be configured as a hammer drill, for example, or an impact drill driver comprising a percussion mechanism. In a design of the hand-held power tool  100  as a hammer drill, the gearing  120  is configured as a spur gear. It should be noted, however, that the present disclosure is not limited to drill drivers, hammer drills or impact drill drivers, but can generally be used in hand-held power tools that comprise a housing portion corresponding to the above-described housing portion  150  with at least two intermediate elements  170  and a rechargeable battery pack  190 . The heavier the hand-held power tool  100  is, the more important the redistribution of forces is. The hand-held power tool  100  preferably has a total weight greater than or equal to 4 kg. 
       FIG.  2    shows the hand-held power tool  100  of  FIG.  1    when the hand-held power tool  100  falls from a height of in particular more than one meter and the hand-held power tool  100  lands or impacts on the rechargeable battery pack  190  or on the edge  196 . This results in impact energy in the direction of the arrows  201 ,  202 , which produces a rotational movement of the rechargeable battery pack  190  along an arrow  203  or clockwise and directs the impact energy along an arrow  204  toward the weak point  105  on the guide rail  162 . However, support, i.e., secondary support, is again provided by the at least two intermediate elements  170 . When the rechargeable battery pack  190  rotates along the arrow  203 , the rechargeable battery pack  190  is driven comparatively strongly out of the guide rails  162 ,  192 . The secondary support creates a support triangle between the locking element  194  and the at least two intermediate elements  170  along the illustrative line  210 . The support triangle reduces the rotation of the rechargeable battery pack  190 . This slows the forced movement of the rechargeable battery pack  190  out of the guide rails  162 ,  192  and reduces the load on the weak point  105 . 
       FIG.  3    shows the rechargeable battery pack interface  160  and the housing portion  150  of  FIG.  1    and  FIG.  2    in a resting state or an unloaded state.  FIG.  3    illustrates a specified distance  301  formed between the lateral surface  152  of the housing portion  150  and the lateral surface  191  of the rechargeable battery pack  190  which is disposed such that it faces the housing portion  150 . The two lateral surfaces  152 ,  191  are preferably disposed plane-parallel to one another, whereby the specified distance  301  is formed of the distance between the two lateral surfaces  152 ,  191 . The specified distance  301  is preferably 2.5 mm ± 1 mm. 
       FIG.  4    shows the housing portion  150  of the housing  110  of the hand-held power tool of  FIG.  1    to  FIG.  3    with the preferably two housing half-shells  151 . Each housing half-shell  151  is preferably provided with at least one intermediate element  170 . The intermediate elements  170  are illustratively configured to be rectangular and have a height  401 , a width  402  and a thickness  403 . The illustrative two intermediate elements  170  are moreover spaced apart from one another by a distance  405 . 
     According to one embodiment, the height  401  is 30 mm, the width  402  is 30 mm and the thickness  403  is between 2 mm and 8 mm. The thickness is preferably 5 mm. The distance  405  is 20 mm, for example. 
     It should be noted that the stated dimensions of the height  401 , the width  402  and the distance  405  are merely exemplary in nature and should not be seen as a limitation of the present disclosure. It should furthermore be noted that the intermediate elements  170  can have any shape; e.g., round, oval, configured as a triangle or a polygon having more than four corners. The at least two intermediate elements  170  can likewise be configured with different shapes and dimensions. It is furthermore also possible that more than two intermediate elements  170  be provided.