Abstract:
A hand-held power tool, has a main element having a tool axis, a center of gravity, and a normal axis which extends perpendicular to the tool axis and through the center of gravity, and the tool axis and the normal axis define a plane of motion, a handle supported in the plane of motion such that it is movable relative to the main element, a spring unit connecting the handle with the main element, the spring unit including a spring element and is provided to at least substantially define a trajectory of at least one portion of the handle in the plane of motion under an influence of a load force which is triggered when the handle is moved out of a neutral position and approaches the main element which is stationary, the handle having a handle body, a rotary element which connects the handle body and the main element and in interaction with the spring unit defines a joint-free rotation axis about which the handle rotates in the plane of motion when a motion takes place relative to the main element, and wherein the rotary element is supported such that it is rotatable relative to the main element and to the handle body.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a division of U.S. patent application Ser. No. 12/298,414 filed on Oct. 24, 2008, which claims its priority from German patent application DE 10 2006 029 630.3 filed on Jun. 28, 2006. The above identified U.S. patent application and German patent application, whose subject matter is incorporated here by reference, provide the basis for a claim of priority of invention under 35 USC 119(a)-(d). 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention is directed to a hand-held power tool, in particular a rotary hammer and/or chisel hammer, with a main element and a handle. 
         [0003]    A hand-held power tool with a main element and a handle has been described. To dampen a transmission of vibrations of the main element to the handle, the handle is supported such that it is movable relative to the main element, and it is connected with the main element via a spring element. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention is directed to a hand-held power tool, in particular a rotary hammer and/or chisel hammer, with a main element—which includes a tool axis, a center of gravity, and a normal axis, which extends perpendicularly to the tool axis and through the center of gravity, the tool axis and the normal axis defining a plane of motion—and which includes a handle, which is supported in the plane of motion such that it is movable relative to the main element, and including a spring unit having at least one spring element and which connects the handle with the main element. 
         [0005]    It is provided that the spring unit is provided to at least substantially define a trajectory of at least one portion of the handle in the plane of motion under the influence of a load force, which is triggered when the handle is moved out of a neutral position and approaches the stationary main element. As a result, a particularly great stability of the handle and an advantageous tactile feeling of security in the handling of the hand-held power tool may be attained without negatively affecting the mobility of the handle in the plane of motion. 
         [0006]    The hand-held power tool is preferably provided with guide means, which are provided to prevent the handle from becoming displaced perpendicularly to the plane of motion. The handle may be guided using these guide means as they move in the plane of motion. In this context, a motion of a rigid body “in” the plane of motion refers, in particular, to a planar motion of this rigid body at least substantially parallel to the plane of motion. In this context, a motion of the rigid body “at least substantially parallel” to the plane of motion refers, in particular, to a motion with which a motion component that is perpendicular to the plane of motion comprises less than 15%, preferably less than 10%, and particularly preferably less than 5% of the total motion of the rigid body. The trajectory is preferably a curved path that includes an axial component along the tool axis and a normal component along the normal axis. The trajectory of the portion of the handle is “specified”, in particular, “by the spring unit” when the portion of the handle is guided—while the handle is undergoing its approaching motion—via the exclusive influence of the spring unit in this trajectory. When the handle is making its approaching motion, the portion of the handle may be guided along a path of motion that may deviate from the trajectory due to the influence of parts other than the spring unit. 
         [0007]    The spring unit defines the trajectory “at least substantially” in particular when the path of motion deviates by a small amount, which is 15% at most, advantageously 10% at most, and, particularly preferably, 5% at most of the entire length of the trajectory. In other words: The path of motion is located within a tolerance range around the trajectory, which extends coaxially with the trajectory and transversely to the direction of motion by the small amount of deviation. A “load force” refers, in particular, to an external force that is applied to the hand-held power tool. The load force may be applied to the handle by an operator via its actuation in a working direction. In this context, a “working direction” refers, in particular, to a preferred direction, in which the hand-held power tool is pressed against a tool or a workpiece. The working direction preferably corresponds at least substantially to the tool axis of the main element. For example, the working direction forms an angle of less than 15°, and, in particular, of less than 10°, with the tool axis. The load force may also be a force that is applied to the main element by a workpiece to be worked. 
         [0008]    The term “stationary” main element is intended to clarify that the main element is selected to be a stationary reference system, which is used to describe relative motions of the handle and the main element. The term “stationary position” of the handle or the main element may be understood to be a position of the handle and/or the main element relative to the main element and/or the handle in which no external forces are applied to the handle and/or the main element. A “tool axis” refers, in particular, to an axis that is defined by a tool fitting of the hand-held power tool, along which a tool is guided into the tool fitting. The “main element” may include everything that is fastened to the hand-held power tool except for the handle. The handle is preferably designed as the main handle of the hand-held power tool. In addition to the main handle, the hand-held power tool may also include an auxiliary handle. A “portion” of the handle refers, in particular, to a contiguous subregion of the handle that preferably forms at least 10% of the total volume of the handle. 
         [0009]    When the handle is regarded as a stationary reference system, a high damping effect may be attained when a significant portion of the main element is guided in a trajectory with a motion component along the normal axis when the main element is moved—due to the load force that is applied—out of a neutral position and approaches the stationary handle. A portion such as this is preferably 10 percent by weight, and, in particular, at least 35 percent by weight of the main element, it being possible for a portion of more than 50 percent by weight of the main element to result in a particularly good vibration damping of the handle. 
         [0010]    It is also provided that the spring unit includes support means for supporting the spring element, which—in interaction with the spring element—define the trajectory. It is therefore possible to specify the trajectory, using simple design means, by selecting the design parameters of the hand-held power tool, in particular via the shaping of the support means, their position, etc. 
         [0011]    A high damping effect may be attained when the handle includes a handle body, and the hand-held power tool includes a rotary element that connects the handle body and the main element, the rotary element—in interaction with the spring unit—defining a joint-free rotation axis, about which the handle rotates in the plane of motion when a motion is made relative to the main element. The rotation axis is preferably formed by the instantaneous center of the handle. The instantaneous center is known from the theory of the rigid body. It is a point about which a planar motion of the rigid body may be instantaneously identified as pure rotation, i.e., it is a point that is instantaneously at rest. The instantaneous center of the handle may shift in three dimensions during the motion of the handle relative to the main element itself. 
         [0012]    In a preferred embodiment of the present invention, it is provided that the spring element is designed as a leaf spring. By designing the spring element of the spring unit as a leaf spring, it is possible to attain an advantageous stabilization of the handle perpendicularly to the plane of motion, and to attain high mobility of the handle in the plane of motion using simple design means and in a cost-effective manner, by designing the leaf spring with a specific profile. A main deformation direction of the leaf spring preferably corresponds to an axis in the plane of motion, in particular the tool axis. 
         [0013]    It is also provided that the handle is held in the neutral position by the spring element. As a result, it is possible to eliminate further components, installation space, assembly expense, and costs, since an additional retaining element which would be used to maintain the neutral position may be eliminated. 
         [0014]    In a further embodiment of the present invention, it is provided that the spring unit includes support means for supporting the spring element, and the spring element rolls on the support means when the handle moves relative to the main element. Particularly high stability in the support of the spring element may be attained as a result. The trajectory may be defined easily and in a flexible manner by selecting the position of the support means relative to the handle and its shape, in particular its radius. 
         [0015]    When the hand-held power tool includes a first housing element and a second housing element, a fastening element for fastening the first housing element to the second housing element, and support means for supporting the spring element, which is fixed in position on the fastening element, it is possible to advantageously reduce installation space and assembly expense. The first and second housing elements are preferably designed as an assembly shell and/or a cover shell, in particular of the main element. To further reduce the manufacturing expense, the support means may be designed as a single piece with the fastening element. 
         [0016]    A particularly stable support of the spring element may be attained using simple design means and in a compact manner when the spring element includes a subregion that encloses the fastening element at least substantially. 
         [0017]    The assembly expense may be further reduced when the hand-held power tool includes clamping means for clamping the spring element. A particularly stable and compact clamp connection may be attained when the spring element includes a subregion that encloses the clamping means. 
         [0018]    It is furthermore provided that the handle includes a handle body, and the hand-held power tool includes a housing element, a bellows unit, which connects the main element with the handle body, and a fixing element, which is provided to fix, at the least, the bellows unit and the spring element on the housing element. The number of fastening elements may be advantageously reduced as a result. 
         [0019]    The present invention is also directed to a hand-held power tool, in particular a rotary hammer and/or chisel hammer, with a main element, which includes a housing element, and a handle, which includes a handle body. It is provided that the hand-held power tool includes a fastening module, which may be removed from the handle body and inserted in the housing element, the fastening module forming a fastening interface for fastening the handle body to the main element. An advantageous module design of the hand-held power tool and simple assembly may be attained as a result. The housing element is preferably designed as an assembly shell of the main element. The assembly expense may be further reduced when the fastening module is provided to establish the form-fit connection with the main element. 
         [0020]    When the handle body is connected with the main element via a vibration-decoupling unit that is installed on the fastening module, it is possible to eliminate installation space and fastening elements. Assembly expense may be minimized when the vibration-decoupling unit is clamped together with the fastening module. 
         [0021]    It is also provided that the fastening module includes a bellows unit, which connects the handle body and the main element. As a result, it possible to attain—in addition to the fastening function of the fastening module—an advantageous safeguard against pinch injuries and penetration by dirt particles. 
         [0022]    Further advantages result from the description of the drawing, below. Exemplary embodiments of the present invention are shown in the drawing. The drawing, the description, and the claims contain numerous features in combination. One skilled in the art will also advantageously consider the features individually and combine them to form further reasonable combinations. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  shows a rotary hammer and/or chisel hammer with a main element and a handle, which is connected with the main element via a leaf spring, 
           [0024]      FIG. 2  is a simplified view of the rotary hammer and/or chisel hammer in a neutral position, 
           [0025]      FIG. 3  shows a trajectory of a portion of the handle, 
           [0026]      FIG. 4  shows a trajectory of a further portion of the handle, 
           [0027]      FIG. 5  shows the rotary hammer and/or chisel hammer with the handle, which has approached the main element. 
           [0028]      FIG. 6  shows the handle of the rotary hammer and/or chisel hammer, which has been separated from the main element, 
           [0029]      FIG. 7  shows a connection region in  FIG. 1 , in an enlarged view, 
           [0030]      FIG. 8  shows a further connection region in  FIG. 1 , in an enlarged view, 
           [0031]      FIG. 9  shows an exploded view of the handle in  FIG. 6 , 
           [0032]      FIG. 10  shows the rotary hammer and/or chisel hammer in  FIG. 1 , with a rigidly coupled handle, and 
           [0033]      FIG. 11  shows the handle of the rotary hammer and/or chisel hammer in  FIG. 10 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0034]      FIG. 1  shows a hand-held power tool  10 , which is designed as a rotary hammer and/or a chisel hammer. It includes a main element  12  and a handle  14 . Main element  12  includes a housing having an assembly shell—which is designed as a first housing element  16 , in which, when assembled, inner components of hand-held power tool  10  are fixed in position—and having a cover shell, which is designed as a second housing element  18 . When hand-held power tool  10  is in the assembled state, first housing element  16  is screwed together with second housing element  18 . For this purpose, first housing element  16  includes two fastening elements  20 ,  22 , which are designed as screw receptacles, each of which—in the installed state—accommodates a screw. 
         [0035]    Hand-held power tool  10  also includes a tool fitting  24 , in which a tool, e.g., a drill or a chisel, may be inserted. Tool fitting  24  includes a cylindrical cavity  26 , in which the tool may be inserted in an insertion direction  28  along an axis, which is referred to as tool axis  30  in this description. A drive unit, which is designed as an electric motor and is not depicted in the figure, is also supported in main element  12 . Center of gravity  32  of main element  12  is depicted schematically with a cross. A normal axis  34  extends through center of gravity  32 , perpendicularly to tool axis  30 . 
         [0036]    Handle  14  includes a handle body  36  with a housing element  38 , which is designed as a handle pot, and in which inner components of handle  14  are installed. Handle  14  also includes a handle cover  40  (see also  FIG. 9 ). Handle  14  is designed as a bow-shaped assembly, in which the ends of the bow are oriented along tool axis  30 . Handle body  36  is connected with housing elements  16 ,  18  of main element  12  via two bellows units  42 ,  44 . Via bellows units  42 ,  44 , it is possible to attain an advantageous seal and protection for the operator against pinch injuries. In addition, handle  14  is supported such that it is movable relative to main element  12 , and it is connected with main element  12  via a vibration-decoupling unit  45 . Vibration-decoupling unit  45  is provided to decouple a transfer of vibrations of main element  12  to handle  14 . For this purpose, vibration-decoupling unit  45  includes a spring unit  46 , which includes a spring element  48  designed as a leaf spring, and support means  50  for supporting spring element  48  in main element  12 . Vibration-decoupling unit  45  also includes a rotary element  52 , which is designed as a lever element. Hand-held power tool  10  depicted in  FIG. 1  is located in a neutral position, in which no external forces are applied to main element  12  or handle  14 . 
         [0037]    Support means  50  are designed as a single piece with fastening element  20 . Support means  50  include an annular subregion, which forms fastening element  20  designed as a screw receptacle. A projection  54  is integrally formed with this subregion, which extends along normal axis  34  in the direction toward tool axis  30  and forms a mating surface  56  for placement of spring element  48  whose function is described below. Spring element  48  includes a first subregion  58 , which is designed as an eyelet and encloses fastening element  20  and/or is rolled around fastening element  20 . Starting from subregion  58  outward, spring element  48  continues in the direction toward tool axis  30  and includes a center subregion  60 , which—in the neutral position of hand-held power tool  10  shown in FIG.  1 —bears against a mating surface  62  formed on a wall of housing element  16  of main element  12 . In a variant of the embodiment, it is feasible to use a foamed material as the layer between subregion  60  and mating surface  62 . 
         [0038]    Spring element  48  is also supported in a connection region  64  of hand-held power tool  10 , connecting region  64  being enclosed by bellows unit  42 . By locating the bearing point of spring element  48  in connection region  64 , it is possible to attain a particularly compact design of handle  14 , since it is possible to eliminate bearing space in handle body  36 . An end  66  of spring element  48  is supported in connection region  64 , end  66  being attached to handle body  36  via a fixing element  68 . To attach end  66  to fixing element  68 , hand-held power tool  10  is provided with clamping means  70 . End  66  is clamped between clamping means  70  and fixing element  68 . Clamping means  70  are screwed together with handle body  36 . End  66  of spring element  48  is clamped between clamping means  70  and fixing element  68  in a non-positive and form-fit manner. The configuration of clamping means  70 , end  66 , and fixing element  68 , and the attachment of this configuration to handle body  36  are shown in greater detail in  FIG. 9 . End  66  is designed as a parabolic section that encloses clamping means  70 . 
         [0039]    In addition, a switch  72  is installed in housing element  38 , which is designed as a handle pot. Switch  72  may be actuated by an operator using a press button  74 , which is swivelably supported in the handle pot, in order to start and stop an operation of hand-held power tool  10 . An electrical cable connection  76  is also shown, which extends from switch  72  to a cable guide  78 , which has been inserted in housing element  38 . Inside handle body  36 , cable connection  76  is clamped between segments  80 . 
         [0040]    Rotary element  52  is supported such that it may rotate relative to main element  12  and handle body  36 . Rotary element  52  is hingedly supported on one side around a rotation point  82 , which is fixed with main element  12  and corresponds to the center point of fastening element  22 . On the other side, rotary element  52  is also hingedly supported around a rotation point  84 , which is fixed with handle body  36 . In addition, it is designed as a lever element that includes two lever arms  86 ,  88  (see  FIG. 9 ). Lever arms  86 ,  88  are hingedly supported in a lever receptacle  90 , which is fixedly connected with handle body  36 . Lever receptacle  90  is located in a connection region  92 , which is enclosed by bellows unit  44 . Lever arms  86 ,  88  are also hingedly supported on fastening element  22 , which is designed as a screw receptacle. Lever arms  86 ,  88  are described in greater detail with reference to  FIG. 9 . 
         [0041]      FIG. 2  shows hand-held power tool  10  in a view—which has been simplified, for clarity—in the neutral position shown in  FIG. 1 . In addition to the components described with reference to  FIG. 1 , further fixing elements  94 ,  96 ,  98  for fixing the bellows units  42 ,  44  are depicted schematically. Fixing elements  94 ,  96 , which are fixedly connected with main element  12 , are used to fix bellows unit  42  and/or  44  to main element  12 . Fixing element  98 , which is fixedly connected with handle body  36 , is used to fix bellows unit  44  on handle body  36 . Handle  14  is held in the neutral position by spring element  48 . In its neutral position, handle body  36  is acted upon with a spring force of spring element  48 , which holds handle body  36  in its neutral position. If handle  14  is located outside of its neutral position, spring element  48  tends to return handle  14  to its neutral position. In order to be able to initiate a motion of handle body  36 , which is in the neutral position, a load force that is greater than the spring force must be exerted against the spring force. 
         [0042]    It is assumed that an operator actuates handle body  14  and, in order to machine a work piece (not depicted), he presses hand-held power tool  10  against the work piece in a working direction  100 . The operator exerts a load force  102  in working direction  100  on handle body  36 , which, if the force is strong enough, causes handle  14  to move out of the neutral position shown and approach main element  12 . Rotary element  52  is used as guide means to guide this motion in a plane of motion, which passes through tool axis  30  and normal axis  34 . Rotary element  52  prevents handle  14  from becoming displaced perpendicularly to the plane of motion. Spring element  48 , which is designed as a leaf spring, provides an additional stabilizing function perpendicularly to the plane of motion. Spring element  48  includes a spring blade ( FIG. 9 ), which, in the installed state, extends along transverse axis  106 —which is perpendicular to the plane of motion—along a major portion of the width (i.e., the extension along transverse axis  106 ) of main element  12 . The main direction of deformation of spring element  48  is therefore oriented along tool axis  30 . In addition, spring element  48  prevents handle  14  from becoming displaced perpendicularly to the plane of motion. Spring element  48  may therefore result in a high level of mobility of handle  14  in the plane of motion, and, in combination with rotary element  52 , an effective guidance of a motion of handle  14  in the plane of motion may be attained. Furthermore, spring blade  104  is profiled such that a load placed on spring element  48  when handle  14  is moved relative to main element  12  is distributed homogeneously across the entire extension of spring blade  104  along transverse axis  106 . This makes it possible to material effectively, and undesired tension peaks may be prevented. To further stabilize handle  14  along transverse axis  106 , main element  12  includes reinforcement ribs  108  in the range of motion of spring element  48  and lever arm  86 ,  88  (see  FIG. 1 ). Reinforcement ribs  108  are used as lateral stops and provide additional reinforcement for housing elements  16 ,  18 . 
         [0043]    A trajectory is defined by spring unit  46 , along which a portion of handle  14 —specifically, upper connection region  64  of handle  14 —is guided when main element  12  is approached. In the present exemplary embodiment, spring element  48  rolls along support means  50 —which is provided with a special profile—and, specifically, on mating surface  56 , when handle  14  approaches main element  12 , having been triggered by load force  102 . Via this rolling motion of spring element  48 , upper connection region  64  is guided along a trajactory, which is depicted schematically in the figure. The trajectory is designed as a circular path, center point  112  of which corresponds to a contact point of mating surface  56 , at which spring element  48  and support means  50  separate from each other in the neutral position. When handle  14  undergoes inward spring deflection, upper connection region  64  therefore makes a tilting motion along trajectory  110 , which is designed as a circular segment. As shown in  FIG. 3 , trajectory  100  includes an axial component  114  along tool axis  30 , and a normal component  116  along normal axis  34 . In this example, normal component  116  of trajectory  110  constitutes 25% of axial component  114 . Advantageously, in order to attain an effective damping effect, normal component  116  may be between 15% and 35% of axial component  114 . As a result, the motion of upper connection region  64  of handle  14  is advantageously adapted to a main oscillation direction of main element  12 , which is essentially oriented along tool axis  30 . When handle  14  makes an approaching motion, lower connection region  92  makes a swiveling motion around rotation point  82  of fastening element  22 —which is used as a bearing point for supporting rotary element  52  in main element  12 —along a trajectory  118 , which is designed as a circular segment. As shown in  FIG. 4 , trajectory  118  includes a normal component  120  and an axial component  122 ; axial component  122  constitutes 66% of normal component  120 . 
         [0044]    The total motion of handle  14  in the plane of motion may be depicted as rotation around an instantaneous center. This instantaneous center represents a joint-free rotation axis  124 , about which handle  14  rotates. The instantaneous center is located at the intersection point of path normals  126 ,  128  of trajectories  110  and  118  of upper and lower connection regions  64  and  92 , respectively. The position of rotation axis  124  depends on an angle α, which is defined by a straight line that extends through rotation points  82 ,  84  and corresponds to path normal  128 , and by tool axis  30 . Angle α represents the inclination of rotary element  52  relative to tool axis  30 . The position of rotation axis  124  depends on the position and shaping of support means  50 , in particular on the position relative to connection region  64  and the radius of the annular subregion. In the present exemplary embodiment, angle α has a value of 25°. Furthermore, in this embodiment, the position of support means  50  in the plane of motion and the radius of the annular subregion of support means  50  were selected such that the instantaneous centers of handle  14  and main element  12  coincide, thereby making it possible to optimally compensate for oscillation motions of main element  12  by handle  14  and to attain a particularly high level of operator comfort. Rotation axis  124  is situated entirely in front of handle  14 . Handle  14  is situated behind tool fitting  24 , relative to tool axis  30 . In one variant of the embodiment, the hinged support of lever arms  86 ,  88  in lever receptacle  90  may be eliminated. In this case, the instantaneous center of handle  14  coincides with rotation point  82  in fastening element  22 . 
         [0045]    Hand-held power tool  10  is shown in  FIG. 5  after handle  14  has approached main element  12 . In addition, the rolling motion of spring element  48  on support means  50  is made clear by comparing  FIGS. 2 and 5 . Main element  12  also includes a stop  125  (see  FIG. 1 ), via which spring element  48  may be arrested when main element  12  is approached. In one variant of the embodiment, it is feasible for stop  125  to be provided with a foamed material in order to dampen the impacts. 
         [0046]    In  FIG. 6 , handle  14  is shown separate from main element  12 . Handle body  36  with housing element  38 —which is designed as a handle pot—and handle cover  40  are shown. Press button  74  and cable guide  78  are supported in handle body  36 . Bellows units  42 ,  44  are attached to handle body  36 . Bellows units  42 ,  44  each include a body  127 ,  129 , which form a bellows, and a fixing region  130  and  132 , which is integrally formed with body  127  and  129 . Fixing regions  130  and  132  each include an annular end  134  and  136 , which forms a groove  138  and  140  with body  127  and  129 . Fixing elements  94 ,  96  for fixing bellows units  42 ,  44  on main element  12  are also shown; they extend out of connection regions  64 ,  92  ( FIG. 1 ). Spring element  48  also extends out of upper connection region  64 , while rotary element  52  and an electrical connection cable  142  for connecting switch  72  ( FIG. 1 ) to the electric motor extend out of lower connection region  92  ( FIG. 1 ). Handle  14  shown in  FIG. 6  is designed as a pre-installation assembly, which is pre-installed before hand-held power tool  10  is assembled, and which is referred to below as the handle assembly. 
         [0047]    When hand-held power tool  10  is assembled, this handle assembly is inserted in first housing element  16 —which is designed as an assembly shell—of main element  12 . 
         [0048]    This assembly is described with reference to  FIG. 1  and to  FIGS. 7 and 8 , which show connection regions  64 ,  92  in  FIG. 1  in an enlarged view. When the handle assembly is inserted into housing element  16 , subregion  58 —which is designed as an eyelet—of spring element  48 , and lever arms  86 ,  88  ( FIG. 9 ) are slid onto fastening means  20 ,  22 —which are designed as screw receptacles—of main element  12 . At the same time, via end  134  and  136 , and groove  138  and  140  of fixing region  130  and  132  of bellows unit  42  and  44  establish a groove-spring connection with housing element  16 . To securely fix bellows units  42 ,  44  on main element  12 , handle  14  is provided with fixing elements  94 ,  96 , which are made of plastic, as a support frame. In the installed state, fixing regions  130  and  132  of bellows unit  42  and  44  are clamped between housing element  16  of main element  12  and fixing element  94  and  96 . Bellows units  42 ,  44  are thereby prevented from moving inwardly. After the electrical contacts are established, in particular via connection cable  142 , second housing element  18 —which is designed as a cover shell—of main element  12  is slid on and is screwed together with first housing element  16 . 
         [0049]    The assembly of handle assembly will be explained with reference to  FIG. 9 , which is an exploded view of the handle assembly. As shown in the figure, handle body  36  is composed of housing element  38 —which is designed as a handle pot—and handle cover  40 , which is fixed to handle pot in the installed state. Transverse axis  106 , which is oriented in parallel with spring blade  104  of spring element  48  in the installed state, is shown for clarity. In a first assembly step, clamping means  70 , which are designed as a vise plate, and fixing element  68  are clipped onto spring element  48 . Next, upper bellows unit  42 —which is reinforced with fixing element  94  designed as a support frame—is slid onto fixing element  68 . The assembly produced in the previous steps is then inserted into housing element  38 . This assembly is now screwed onto housing element  38  using two screws  144 . Screws  144  are inserted through openings in fixing element  68  and spring element  48  into screw receptacles of clamping means  70 . Lever receptacle  90  is then inserted through lower bellows unit  44  and into housing element  38 . Two latch hooks  146  of lever receptacle  90  snap into recesses in housing element  38  (not depicted in the figure). Press button  74  is then inserted into housing element  38 . A swiveling axis  148 —in the form of two bearing bolts—is integrally formed with press button  74 , and it snaps in place in a bearing region  150  of housing element  38 . Cable connection  76  is then inserted—together with cable guide  78 , which is designed as a spherical grommet—into housing element  38 , and it is secured against being accidentally pulled out with the aid of a retaining plate  152  by tightening a screw  154 . Cable connection  76  is connected to switch  72 , which is then inserted into housing element  38 . Handle cover  40  includes detent elements  156 , which are designed as retaining projections, and which snap into housing element  38  when handle cover  40  is slid on. Handle cover  40  also includes retaining segments  158 , which are used to fix switch  72  and press button  74  in place without play when handle cover  40  is slid into place. Handle cover  40  and housing element  38  are then screwed together with lever receptacle  90  using two screws  160 . Screws  160  are inserted through openings in housing element  38  into screw receptacles of lever receptacle  90 . Lever arms  86 ,  88  are then placed on lever receptacle  90 . Lever arms  86 ,  88  include two grooves and two pegs on their sides that face each other. When lever arms  86 ,  88  are connected, a fixed, non-rotatable connection is attained. In the next step, fixing element  96 , which is designed as a support frame, is slid past lever arms  86 ,  88  into lower bellows unit  44 . Fixing element  96  prevents lever arms  86 ,  88  from falling out. When the assembly steps described above are completed, all of the components of the handle assembly described here are captively integrated in the handle assembly. 
         [0050]    The handle assembly also has a flexible, modular design. Bellows unit  42 —together with fixing elements  68 ,  94  and bellows unit  44  with fixing elements  96 ,  98 —form two fastening modules  159  and  161 , each of which forms a fastening interface for attaching handle body  36  to main element  12  (see  FIGS. 7 and 8 ). In particular, as described above, the attachment to main element  12  via these fastening modules  159 ,  161  is realized by establishing groove-spring connections, thereby making it possible to attain particularly easy assembly. It is also possible to attain a simple replacement of fastening modules  159 ,  161 . After housing element  18 —which is designed as a cover shell—is removed, fastening modules  159 ,  161 , which have been inserted into housing element  16  designed as an assembly shell, may be easily removed from housing element  16  without the use of tools, handle  14  being removed from main element  12 . After screws  144 ,  160  are removed, fastening modules  159 ,  161  may be removed from handle body  36 . Handle body  36  may be used in combination with a further main element of a further hand-held power tool, without the need to redesign handle body  36  any further. This is depicted in  FIG. 10 .  FIG. 10  shows a further hand-held power tool  162 —which is designed as a chisel hammer and/or rotary hammer—with a main element  164 . Main element  164  includes a first housing element  166  designed as an assembly shell, and a second housing element  168  designed as a cover shell. A handle  170  is attached to main element  164 , which is shown separated from main element  164  in  FIG. 11 . 
         [0051]    Handle  170  is composed of handle body  36  and two fastening modules  172 ,  174 , which, in the installed state of hand-held power tool  162 , are inserted into housing element  166  of main element  164 . 
         [0052]    Before hand-held power tool  162  is assembled, fastening modules  172 ,  174  are screwed together—as described above for fastening modules  159 ,  161 —using screws  144  and  160  with housing element  38  designed as a handle pot. The handle assembly, which is now complete and is shown in  FIG. 11 , is then inserted into housing element  166 . When fastening modules  172 ,  174  are inserted, a groove-spring connection is established between fastening modules  172 ,  174  and housing element  166 . For this purpose, fastening module  172  and  174  includes grooves  176  and  178 , into which housing element  166  engages when it is inserted. After the electrical contacts are established, in particular using connection cable  142 , housing elements  166 ,  168  are screwed together. In this process, screws are guided through openings  180 ,  182  of fastening modules  172 ,  174 . 
         [0053]    It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above. 
         [0054]    While the invention has been illustrated and described as embodied in a hand-held power tool, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. 
         [0055]    Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.