Patent Publication Number: US-11034012-B2

Title: Hand-held power tool in which the direction of rotation can be set

Description:
This application is a 35 U.S.C. § 371 National Stage Application of PCT/EP2016/080141, filed on Dec. 7, 2016, which claims the benefit of priority to Serial No. DE 10 2015 226 087.9, filed on Dec. 18, 2015 in Germany, the disclosures of which are incorporated herein by reference in their entirety. 
     BACKGROUND 
     The disclosure relates to a hand-held power tool having a drive unit for rotationally driving an output spindle, wherein the drive unit can be changed over between a first direction of rotation and a second direction of rotation in order to make it possible to drive the output spindle in the first or second direction of rotation, wherein at least one operating element is provided to initiate a changeover operation for changing over the drive unit between the first direction of rotation and the second direction of rotation. 
     The prior art discloses such hand-held power tools having a drive unit with a drive motor for rotationally driving an output spindle which can be changed over between a first direction of rotation and a second direction of rotation. These hand-held power tools have an operating element for initiating the operation of changing over between the two different directions of rotation. 
     In addition, DE 201 07 583 U1 discloses a hand-held power tool having a monostable switch for reversing the direction of rotation, which switch comprises a circuit board having switching elements fitted thereto and a switching handle for actuating the switching elements. In this case, the switching handle is in the form of a switching rocker or rocker switch for actuating either the one switching element or the other switching element by means of tilting and is rotatably mounted on the housing of the hand-held power tool. In this case, the monostable switch comprises a spring rod which is unloaded in a stable central position of the switching handle and can be deflected in an elastically deformable manner by tilting the switching handle. The monostable switch can therefore actuate two different switching elements from its stable central position. 
     SUMMARY 
     The disclosure provides a new hand-held power tool having a drive unit for rotationally driving an output spindle, wherein the drive unit can be changed over between a first direction of rotation and a second direction of rotation in order to make it possible to drive the output spindle in the first or second direction of rotation, wherein at least one operating element is provided to initiate a changeover operation for changing over the drive unit between the first direction of rotation and the second direction of rotation. The at least one operating element is in the form of a monostable switching element. 
     The disclosure therefore makes it possible to provide a hand-held power tool in which the operating element for initiating the changeover operation between the first direction of rotation and the second direction of rotation is in the form of a monostable switching element. It is therefore possible for a user of the hand-held power tool to change over the drive unit between the first direction of rotation and the second direction of rotation in a simple and uncomplicated manner. 
     The at least one operating element in the form of a monostable switching element is preferably assigned a sensor unit which is designed to generate a corresponding actuation signal when the operating element is actuated. It is therefore possible to signal the actuation of the operating element in a simple manner. 
     The actuation signal can preferably be used to set a respectively desired direction of rotation of the output spindle. It is therefore possible to safely and reliably set the current direction of rotation of the output spindle. 
     The sensor unit preferably has a mechanical, electrical, magnetic and/or optical sensor. Actuation of the operating element can therefore be captured in a cost-effective manner. 
     According to one embodiment, a direction of rotation detection unit is provided and is designed to detect a respectively current direction of rotation of the drive unit. A current direction of rotation of the drive unit can therefore be expediently and reliably detected. 
     A direction of rotation detection unit is preferably provided and is designed to indicate a request to initiate a changeover operation for changing over the drive unit between the first direction of rotation and the second direction of rotation when predefined operating conditions occur. A request to initiate a changeover operation for changing over the drive unit between the first direction of rotation and the second direction of rotation can therefore be indicated in a safe and uncomplicated manner. 
     The at least one operating element in the form of a monostable switching element preferably has a switching rocker, a pushbutton or a slide. The at least one operating element in the form of a monostable switching element can therefore be implemented in a versatile and expedient manner. 
     The at least one operating element in the form of a monostable switching element is preferably assigned at least one spring element which moves the operating element into a stable position. The at least one operating element in the form of a monostable switching element can therefore be safely and reliably moved into a stable position. 
     The at least one operating element in the form of a monostable switching element is preferably provided with an illumination means and the illumination means is designed to indicate a request to initiate a changeover operation for changing over the drive unit between the first direction of rotation and the second direction of rotation when predefined operating conditions occur. A request to initiate a changeover operation for changing over the drive unit between the first direction of rotation and the second direction of rotation can therefore be indicated in a simple manner. 
     According to one embodiment, the drive unit has a drive motor and control electronics are provided and are designed to cause a changeover operation for changing over the drive motor between the first direction of rotation and the second direction of rotation when the at least one operating element in the form of a monostable switching element is actuated. Actuation of the at least one operating element in the form of a monostable switching element can therefore safely and precisely cause a changeover operation for changing over the drive motor between the first direction of rotation and the second direction of rotation. 
     The control electronics are preferably designed to cause the changeover operation for changing over the drive motor between the first direction of rotation and the second direction of rotation only when the drive motor is at a standstill. It can therefore be reliably ensured that the changeover operation for changing over the drive motor between the first direction of rotation and the second direction of rotation is caused only when the drive motor is at a standstill. 
     The control electronics are preferably designed to brake the drive motor to a standstill in order to enable the changeover operation for changing over the drive motor between the first direction of rotation and the second direction of rotation. The control electronics can therefore make it possible to initiate the changeover operation for changing over the drive motor between the first direction of rotation and the second direction of rotation, to be precise irrespective of whether or not the drive motor is at a standstill. 
     According to one embodiment, the at least one operating element in the form of a monostable switching element has a touch-sensitive screen. The at least one operating element in the form of a monostable switching element can therefore be operated in a simple manner. 
     The touch-sensitive screen is preferably designed to make it possible to indicate a request to initiate a changeover operation for changing over the drive unit between the first direction of rotation and the second direction of rotation and to initiate the changeover operation. A request to initiate a changeover operation for changing over the drive unit between the first direction of rotation and the second direction of rotation can therefore be indicated and the changeover operation can be initiated in an uncomplicated manner and in a manner which is clearly discernible for a user. 
     According to one embodiment, the hand-held power tool is in the form of a cordless screwdriver or a cordless drill/screwdriver. The hand-held power tool having the at least one operating element in the form of a monostable switching element can therefore be flexibly implemented in the form of a cordless screwdriver or a cordless drill/screwdriver. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure is explained in more detail in the following description on the basis of exemplary embodiments which are illustrated in the drawings. In the drawings, the same structural elements having identical functionalities each have the same reference numerals and are generally described only once. In the drawings: 
         FIG. 1  shows a perspective view of a hand-held power tool having a communication interface and an operating element for initiating a changeover operation for changing over a drive unit between a first direction of rotation and a second direction of rotation, 
         FIG. 2  shows a partially sectional side view of the hand-held power tool from  FIG. 1  with the drive unit, 
         FIG. 3  shows a longitudinal section of the drive unit of the hand-held power tool from  FIG. 1  and  FIG. 2 , 
         FIG. 4  shows a perspective side view of the operating element from  FIG. 1  with a switching rocker according to one embodiment, 
         FIG. 5  shows a perspective side view of the switching rocker from  FIG. 4  in a stable position of rest and in an unstable switching position, 
         FIG. 6  shows a partially exploded view of the switching rocker from  FIG. 4  and  FIG. 5 , 
         FIG. 7  shows a perspective side view of the operating element from  FIG. 1  with two switching rockers according to one embodiment, 
         FIG. 8  shows a perspective side view of the operating element from  FIG. 1  with a slide according to one embodiment, 
         FIG. 9  shows a cross section of a two-sided monostable slide according to one embodiment, 
         FIG. 10  shows a longitudinal section of the two-sided monostable slide from  FIG. 9 , 
         FIG. 11  shows a perspective partial view of the operating element from  FIG. 1  according to one embodiment, 
         FIG. 12  shows a perspective partial view of the operating element from  FIG. 1  with a pushbutton according to one embodiment, 
         FIG. 13  shows a perspective partial view of the operating element from  FIG. 1  according to one embodiment, 
         FIG. 14  shows a perspective partial view of the operating element from  FIG. 13 , 
         FIG. 15  shows a schematic diagram of the hand-held power tool from  FIG. 1  with the exemplary operating element and the communication interface, 
         FIG. 16  shows a perspective view of a system consisting of the hand-held power tool from  FIG. 1  and an operating unit according to a first embodiment, 
         FIG. 17  shows a flowchart of an interactive program for initiating a changeover operation for changing over a drive unit between a first direction of rotation and a second direction of rotation, 
         FIG. 18  shows a flowchart of a first changeover operation from  FIG. 17 , and 
         FIG. 19  shows a flowchart of a second changeover operation from  FIG. 17 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows an exemplary hand-held power tool  100  having a housing  110  in which at least one drive unit ( 220  in  FIG. 2 ) having at least one drive motor ( 120  in  FIG. 2 ) is arranged for the purpose of rotationally driving an output spindle ( 310  in  FIG. 3 ) or driving an insertion tool which can be arranged in a tool holder  190  and can preferably be exchanged. In this case, the housing  110  has a handle  103  with a manual switch  105 . The drive motor ( 120  in  FIG. 2 ) can be actuated, that is to say switched on and off, via the manual switch  105 , for example, and can preferably be electronically controlled or regulated in such a manner that both reversing operation and specifications with regard to a desired rotational speed can be implemented. 
     In addition, an operating element  106  for initiating a changeover operation for changing over the drive unit ( 220  in  FIG. 2 ) between a first direction of rotation and a second direction of rotation is preferably arranged in the region of the manual switch  105  and can preferably be used to set a direction of rotation of the drive motor ( 120  in  FIG. 2 ) or of the output spindle ( 310  in  FIG. 3 ) which can be at least indirectly driven by the drive motor ( 120  in  FIG. 2 ). The operating element  106  is preferably formed by at least one monostable switching element, for example by a switching rocker ( 406  in FIG.  4 ), a slide ( 706  in  FIG. 8 ) or a pushbutton ( 1235  in  FIG. 14 ). 
     The hand-held power tool  100  preferably has an optional switchable transmission ( 130  in  FIG. 2 ), which can be changed over at least between a first gear and a second gear, and an optional percussion mechanism (not illustrated). By way of illustration, the hand-held power tool  100  is in the form of a percussion drill/screwdriver or a drill/screwdriver, wherein the first gear corresponds to a screwing mode, for example, and the second gear corresponds to a drilling or percussion drilling mode. However, further gears can also be implemented, with the result that the drilling mode is assigned to the second gear and the percussion drilling mode is assigned to a third gear, etc., for example. Alternatively, the hand-held power tool  100  can also be only in the form of a cordless screwdriver or a cordless drill/screwdriver which has at least the operating element  106  for initiating a changeover operation for changing over the drive unit ( 220  in  FIG. 2 ) between the first direction of rotation and the second direction of rotation. In this case, the hand-held power tool  100  can preferably be connected to a rechargeable battery pack  102  for the purpose of being supplied with power in a manner independent of the mains, but may alternatively also be operated from the mains. 
     According to one embodiment, at least one user guidance unit  115  is provided and is designed at least to change over the drive motor ( 120  in  FIG. 2 ) or the output spindle ( 310  in  FIG. 3 ), which can be at least indirectly driven by the drive motor, between the first direction of rotation and the second direction of rotation. The user guidance unit  115  is also preferably designed to set the first or second gear required during the respectively current operation. The user guidance unit  115  can be designed for active and/or passive user guidance during a corresponding operation of changing over between the first direction of rotation and the second direction of rotation. In the case of active user guidance, a user of the hand-held power tool  100  is preferably guided, by means of visual, auditory and/or haptic instructions or requests, to change over in a corresponding changeover operation, whereas a corresponding changeover operation is automatically carried out in the case of passive user guidance and is preferably only indicated to the user. Exemplary implementations of active and passive user guidance are described in detail below. 
     The user guidance unit  115  preferably has at least one operating unit  106 ,  116 ,  117  which can be manually actuated and has at least one operating element, and by way of illustration a first operating element  106 , a second operating element  116  and a third operating element  117 , which can be manually actuated, wherein the operating elements  106 ,  116 ,  117  are designed to initiate a changeover operation for changing over the drive unit ( 220  in  FIG. 2 ) between the first direction of rotation and the second direction of rotation and/or for initiating a changeover operation for changing over the transmission  130  between different gears. According to one embodiment, at least one of the operating elements  116 ,  117  has a touch-sensitive screen ( 1120  in  FIG. 13 ). The touch-sensitive screen is preferably designed to make it possible to indicate ( 1185  in  FIG. 13 ) a request to initiate a changeover operation for changing over the drive unit ( 220  in  FIG. 2 ) between the first direction of rotation and the second direction of rotation and to initiate the changeover operation. 
     The user guidance unit  115  preferably has a mobile computer, for example a smartphone and/or a tablet computer, and/or the operating element  116 ,  117  can be in the form of a display. Alternatively, it is also possible to use other so-called “smart devices”, for example a watch, glasses etc., as the mobile computer. 
     According to one embodiment, the user guidance unit  115  is at least partially integrated in the hand-held power tool  100  and/or is at least partially in the form of an external separate component ( 1040  in  FIG. 16 ). In this case, the display can be integrated in the hand-held power tool  100  and/or can be externally arranged. Changeover instructions can preferably be indicated on the display in order to at least make it easier for a user of the hand-held power tool  100  to operate and/or set, for example, an application-specific operating mode of the hand-held power tool  100 . 
     The hand-held power tool  100  also preferably has a communication interface  1050  which is preferably provided for the purpose of communicating with the user guidance unit  115 , that can preferably be actuated by a user, and is designed to receive, at least from the user guidance unit  115 , changeover instructions for changing over the drive motor ( 120  in  FIG. 2 ) or the output spindle ( 310  in  FIG. 3 ), which can be at least indirectly driven by the drive motor, between a first direction of rotation and a second direction of rotation. The communication interface  1050  is also preferably designed to receive, from the user guidance unit  115 , changeover instructions for changing over the transmission  130  between the two different gears in an application-specific manner. In this case, the communication interface  1050  is at least designed to transmit a control signal to at least one of the operating elements  106 ,  116 ,  117 . In this case, it is preferably possible for at least one of the operating elements  106 ,  116 ,  117 , for example, to generate a request to initiate a changeover operation for changing over the drive unit between the first direction of rotation and the second direction of rotation. It is preferably likewise possible for at least one of the operating elements  116 ,  117 , for example, to generate a request to initiate a changeover operation for changing over the transmission  130  between the two different gears. 
     It is pointed out that the three operating elements  106 ,  116 ,  117  are shown as operating elements which can be used to reverse the direction of rotation in the embodiment shown in  FIG. 1 . However, alternatively, only the operating element  106  or one of the two operating elements  116 ,  117  or the two operating elements  116 ,  117  can also be designed to make it possible to reverse the direction of rotation of the drive unit ( 220  in  FIG. 2 ) or of the drive motor ( 120  in  FIG. 2 ). 
     According to one embodiment, the communication interface  1050  is in the form of a wireless transmission module, in particular in the form of a radio module for wireless communication by means of the Bluetooth standard. However, the transmission module may also be designed for any other wireless and/or wired communication, for example via WLAN and/or LAN. 
     Optional working field illumination  104  is preferably arranged on the housing  110 , by way of illustration in the region of the tool holder  190 , for the purpose of illuminating a working field of the hand-held power tool  100 . In addition, an optional torque limitation element  170  for setting a maximum transmittable torque is assigned to the tool holder  190 . In this case, the torque limitation element  170  may be in the form of a mechanical friction clutch or an electrical torque limitation means. 
       FIG. 2  shows the hand-held power tool  100  from  FIG. 1  which, by way of illustration, has a drive unit  220  for rotationally driving an output spindle ( 310  in  FIG. 3 ), wherein the drive unit  220  can be changed over between a first direction of rotation and a second direction of rotation. The drive unit  220  preferably has a drive motor  120  and an optional switchable transmission  130 . The optional switchable transmission  130  preferably has a transmission housing  136  which is formed, by way of illustration, in two parts with a first transmission housing part  137  and a second transmission housing part  138 . In this case, the first transmission housing part  137  is preferably arranged facing the drive motor  120  and the second transmission housing part  138  is arranged facing the tool holder  190 . However, the transmission housing  136  may also be formed in one part or may have more than two transmission housing parts. The optional switchable transmission  130  is preferably in the form of a planetary transmission which can preferably be changed over at least between two different gears and is described further in  FIG. 3 . 
     According to one embodiment, the optional switchable transmission  130  is assigned a gear changeover unit  210  which is designed to change over the optional switchable transmission  130  between the at least two different gears. This gear changeover unit  210  preferably has at least one actuatable switching ring  140 . The gear changeover unit  210  also preferably has a transmission unit  134 . 
     The transmission unit  134  is preferably designed to transmit an actuation of the actuatable switching ring  140  to a preferably axially displaceable switching element ( 350  in  FIG. 3 ) of the transmission  130 . The gear changeover unit  210  or the switching element ( 350  in  FIG. 3 ) preferably changes over the gear only during operation of the optional switchable transmission  130 , with the result that it is possible to change over a gear only during operation of the optional switchable transmission  130 . 
     According to one embodiment, at least one operating element ( 106  in  FIG. 1 ) is provided for the purpose of initiating a changeover operation for changing over the drive unit  220  between the first direction of rotation and the second direction of rotation. The operating element  106  is preferably in the form of a monostable switching element, for example in the form of a switching rocker ( 406  in  FIG. 4 ), a slide ( 706  in  FIG. 8 ) and/or a pushbutton ( 1235  in  FIG. 14 ). 
     The at least one operating element  106  is preferably assigned a direction of rotation detection unit  160  which is designed to detect a respectively current direction of rotation of the drive unit  220 . The direction of rotation detection unit  160  indicates a request to initiate a changeover operation for changing over the drive unit ( 220  in  FIG. 15 ) between the first direction of rotation and the second direction of rotation, preferably when predefined operating conditions occur, for example in the case of so-called jamming of a drill used as an insertion tool. 
     According to one embodiment, the operating element ( 106  in  FIG. 1 ) is assigned a sensor unit ( 1370  in  FIG. 15 ). The sensor unit  1370  preferably has a mechanical, electrical, magnetic and/or optical sensor and is preferably designed to generate a corresponding actuation signal when the operating element is actuated. The sensor unit  1370  is preferably designed to transmit the actuation signal to a communication interface ( 1050  in  FIG. 1 ) when the at least one operating element  106  is actuated. The actuation signal can preferably be evaluated in order to determine a respectively current direction of rotation of the output spindle ( 310  in  FIG. 3 ). 
     Control electronics  150  are preferably provided and are designed to cause a changeover operation for changing over the drive motor  120  between the first direction of rotation and the second direction of rotation when the at least one operating element ( 106  in  FIG. 1 ) in the form of a monostable switching element is actuated. The control electronics  150  are preferably designed to cause the changeover operation for changing over the drive motor  120  between the first direction of rotation and the second direction of rotation solely when the drive motor  120  is at a standstill. In addition, the control electronics  150  are preferably designed to cause braking of the drive motor  120  to a standstill in order to enable the changeover operation for changing over the drive motor  120  between the first direction of rotation and the second direction of rotation. 
     According to one embodiment, the direction of rotation is reversed between the first direction of rotation and the second direction of rotation by an actuating unit  180  with an actuating motor  182 . The actuating motor  182  is preferably assigned an actuating motor transmission  184 . The actuating motor  182  is preferably designed to cause a changeover operation for changing over the drive unit  220  between the first direction of rotation and the second direction of rotation when activated by the operating element ( 106  in  FIG. 1 ). 
     The communication interface  1050  is preferably designed to transmit a control signal for activating the actuating unit  180  to the actuating motor  182 . In this case, the control signal can be generated in response to actuation of the at least one operating element  116 ,  117  from  FIG. 1 . Alternatively or additionally, the generation of the control signal can preferably be initiated by the user guidance unit  115 , that is to say, for example, by a mobile computer in the form of a smartphone, a tablet computer or another so-called “smart device”, for example a watch, glasses etc., with the result that it is also possible to dispense with providing the operating elements  106 ,  116 ,  117  from  FIG. 1 . According to one embodiment, the generation can also be directly initiated by the communication interface  1050 , for example on the basis of predefined operating parameters, with the result that it is again possible to dispense with providing the operating elements  106 ,  116 ,  117 . 
       FIG. 2  also illustrates the manual switch  105  of the hand-held power tool  100 , which switch is designed to activate and deactivate the drive motor  120 . The manual switch  105  is preferably assigned on on/off switch  107  in this case, wherein the manual switch  105  is preferably in the form of a press button, but may also be in the form of a pushbutton, which is sometimes also referred to as a button. 
       FIG. 3  shows the optional switchable transmission  130  from  FIG. 2 , which is preferably in the form of a planetary transmission and is intended to drive an output spindle  310  of the hand-held power tool  100  from  FIG. 1 , and an optional percussion mechanism  320 . A suitable structure and the method of operation of a corresponding percussion mechanism are sufficiently well known from the prior art, with the result that a detailed description of the optional percussion mechanism  320  can be dispensed with here for the purpose of simplicity and conciseness of the description. 
     The planetary transmission  130  preferably has at least a first and a second planetary gear, by way of illustration a first, a second and a third planetary gear  372 ,  374 ,  376 , which, by way of illustration, make it possible to operate the planetary transmission  130  in a first gear and a second gear. In this case, each gear is preferably assigned to a corresponding operating mode, for example a screwing mode, a drilling mode and/or a percussion drilling mode/percussion screwing mode. For example, a screwing mode for carrying a screwing operation with torque limitation can be provided in a first gear, whereas a drilling operation and/or a drilling and/or screwing operation with a percussion function is/are provided for performance in a second gear. 
       FIG. 3  also illustrates the fact that a changeover operation for changing over the drive unit  220  for driving the output spindle  310  from the first direction of rotation to the second direction of rotation can be enabled, for example, by changing over the drive motor  120 . However, it is pointed out that the configuration of the changeover operation by changing over the drive motor  120  has only an exemplary character and cannot be considered a restriction of the disclosure. 
       FIG. 4  shows, by way of example, an operating element for initiating a changeover operation for changing over the drive unit ( 220  in  FIG. 2 ) between the first direction of rotation and the second direction of rotation, which operating element is in the form of a switching rocker  406 . The switching rocker  406  is preferably fitted above the handle  103  in order to enable easily accessible operation. 
     The switching rocker  406  is preferably a monostable switch which is moved along a guiding web  410 . The switching rocker  406  is preferably in an—upper (by way of illustration in  FIG. 4 )—position of rest ( 510  in  FIG. 5 ), wherein actuation of the switching rocker  406  results in rotation into a switching position ( 520  in  FIG. 5 ), from which the switching rocker  406  preferably independently returns to the position of rest  510 . For this purpose, the switching rocker  406  is preferably assigned at least one spring element ( 610  in  FIG. 6 ) which impinges the switching rocker  406  into the position of rest  510 . 
       FIG. 5  shows the switching rocker  406  from  FIG. 4  in the position of rest  510  and in the switching position  520 . When the switching rocker  406  is actuated, it is preferably rotated from the position of rest  510  into the switching position  520  along the guiding web  410 . In this case, the switching rocker  406  is preferably assigned a sensor unit ( 1370  in  FIG. 15 ) which is designed to generate a corresponding actuation signal when the switching rocker  406  is actuated. The actuation signal can preferably be evaluated in order to determine a respectively current direction of rotation of the output spindle ( 310  in  FIG. 3 ). For this purpose, the sensor unit  1370  preferably has a mechanical, electrical, magnetic and/or optical sensor. For example, the switching rocker  406  can generate a corresponding actuation signal in the sensor unit  1370  via a lever ( 408  in  FIG. 6 ). 
       FIG. 6  shows the switching rocker  406  from  FIG. 4  and  FIG. 5  which is preferably assigned a spring element  610  which is preferably arranged between the switching rocker  406  and a stop  413 . In this case, the spring element  610  is preferably relaxed in the position of rest ( 510  in  FIG. 5 ) and is tensioned in the switching position ( 520  in  FIG. 5 ), with the result that the switching rocker  406  can independently return to the position of rest  510  again from the switching position  520  with the aid of the spring element  610 . 
     In the switching position ( 520  in  FIG. 5 ), the lever  408  is preferably likewise displaced downward owing to the rotation of the switching rocker  406 —downward in  FIG. 6 —along the guiding web  410 . In this case, the lever  408  can preferably act on or interact with a mechanical, electrical, magnetic and/or optical sensor of the sensor unit ( 1370  in  FIG. 15 ). For example, a pushbutton ( 1235  in  FIG. 14 ) can be fitted below the lever  408 , which pushbutton is mechanically actuated by the lever  408  and transmits an electrical signal to control electronics ( 150  in  FIG. 2 ). The control electronics  150  then preferably cause a changeover operation for changing over the drive unit ( 220  in  FIG. 2 ) between the first direction of rotation and the second direction of rotation. 
       FIG. 7  shows an exemplary operating element for initiating a changeover operation for changing over the drive unit ( 220  in  FIG. 2 ) between the first direction of rotation and the second direction of rotation, which operating element is in the form of two switching rockers  1006 ,  1007  by way of illustration, wherein one of the two switching rockers  1006 ,  1007  is respectively preferably provided on one side of the handle ( 103  in  FIG. 1 ). The two switching rockers  1006 ,  1007  are each preferably in the form of a monostable switching element and have, by way of illustration, a position of rest ( 510  in  FIG. 5 ) and a switching position ( 520  in  FIG. 5 ). 
     The two switching rockers  1006 ,  1007  are preferably mechanically decoupled, but may also be optionally connected to one another via a shaft. At least one of the two switching rockers  1006 ,  1007  is preferably assigned a sensor unit ( 1370  in  FIG. 15 ) which is designed to generate a corresponding actuation signal when the switching rocker  1006 ,  1007  is actuated. The actuation signal can preferably be used to set a respectively desired direction of rotation of the output spindle ( 310  in  FIG. 3 ). For this purpose, the sensor unit  1370  preferably has a mechanical, electrical, magnetic and/or optical sensor. By way of illustration, the switching rocker  1006  can generate a corresponding actuation signal in the sensor unit  1370  when actuated via a lever  1008 . 
     By way of illustration, the sensor unit  1370  has a lever  407  which, when the switching rocker  1006  is actuated and the lever  1008  is therefore rotated—downward in  FIG. 7 , is rotated in the anticlockwise direction about a shaft  1009  and in the process actuates an electrical switch  409  of the sensor unit  1370 , which switch transmits an electrical signal to the control electronics ( 150  in FIG.  2 ). The control electronics  150  then preferably cause a changeover operation for changing over the drive unit ( 220  in  FIG. 2 ) between the first direction of rotation and the second direction of rotation, for example by changing the commutation of the drive motor  120  from  FIG. 2 . 
     The switching rocker  1007  is preferably also provided with a corresponding sensor unit  1370 , the electrical switch  409  of which can likewise transmit an electrical signal to the control electronics  150  in the event of actuation, as a result of which the control electronics  150  preferably cause a changeover operation for changing over the drive unit  220  between the first direction of rotation and the second direction of rotation. Alternatively, each of the switching rockers  1006 ,  1007  can be assigned a separate electrical switch  409  which is respectively actuated by a separate lever  407 , wherein the two switches  409  are preferably electrically connected in parallel, with the result that the actuation of one of the two switching rockers  1006 ,  1007  makes it possible to change over the drive unit  220  between the first direction of rotation and the second direction of rotation. 
       FIG. 8  shows an exemplary operating element which is in the form of a monostable switching element and has, by way of illustration, the form of a slide  706 . The slide  706  preferably has at least a first spring element, by way of illustration a first spring element  710  and a second spring element  720 , which make it possible, for example, for the slide  706  to return to a position of rest from a switching position after the slide has been actuated. 
     The slide  706  preferably also has a holder  740 . This holder  740  is preferably arranged around an entraining element  760  which is preferably permanently connected to the direction of rotation detection unit  160 . As a result of the slide  706  being displaced from the position of rest into the switching position, the holder  740  preferably causes a rotational movement of the direction of rotation detection unit  160  about a shaft  762 , preferably via the entraining element  760 , as a result of which a changeover operation for changing over the drive unit ( 220  in  FIG. 2 ) between the first direction of rotation and the second direction of rotation is preferably respectively initiated. 
       FIG. 9  shows another exemplary operating element for initiating a changeover operation for changing over the drive unit ( 220  in  FIG. 2 ) between the first direction of rotation and the second direction of rotation, by way of illustration in the form of a two-sided slide  806  which can preferably be actuated from both sides of the handle  103  from  FIG. 1 . The two-sided slide  806  is preferably in the form of a monostable switching element and has, by way of illustration, a position of rest ( 920  in  FIG. 10 ) and two switching positions ( 910 ,  930  in  FIG. 10 ). 
     The two-sided slide  806  also preferably has a holder  840 . This holder  840  is preferably arranged around an entraining element  760  which is preferably permanently connected to the direction of rotation detection unit  160 . As a result of the two-sided slide  806  being displaced from the position of rest ( 920  in  FIG. 10 ) into one of the two switching positions ( 910 ,  930  in  FIG. 10 ), the holder  840  causes a rotational movement of the direction of rotation detection unit  160  in one direction or another about the shaft  762 , preferably via the entraining element  760 , as a result of which a changeover operation for changing over the drive unit ( 220  in  FIG. 2 ) between the first direction of rotation and the second direction of rotation is preferably respectively initiated. 
     The two-sided slide  806  preferably has a spring element  820  which, by way of illustration, makes it possible for the two-sided slide  806  to return to a position of rest ( 920  in  FIG. 10 ) from one of the two switching positions ( 910 ,  930  in  FIG. 10 ) after the slide has been actuated. 
       FIG. 10  shows the two-sided slide  806  from  FIG. 9  in a position of rest  920  and in two switching positions  910 ,  930 . The two-sided slide  806  preferably has the spring element  820  from  FIG. 9 . The position of rest  920  is characterized in that the spring element  820  is tensioned at least between a first projection  901  and a second projection  902  of the two-sided slide  806  or between a first projection  903  and a second projection  904  of the housing part  905 . By way of illustration, the spring element  820  is tensioned between the first projection  901  and the second projection  902  of the two-sided slide  806  and between the first projection  903  and second projection  904  of the housing part  905 . The spring element  820  is preferably relaxed in the position of rest. Alternatively, the spring element  920  can also be arranged in the tensioned form in the position of rest  920 . 
     If the two-sided slide  806  is actuated—from the right-hand side in  FIG. 10 , the two-sided slide  806  is displaced, by way of illustration, to the left into the first of the two switching positions  910 . In this first of the two switching positions  910 , the spring element  820  is preferably tensioned between the second projection  902  of the two-sided slide  806  and the first projection  903  of the housing part  905 . After the two-sided slide  806  has been actuated, the spring element  820  therefore makes it possible for the two-sided slide  806  to independently return to the position of rest  920  from the switching position  910 . 
     If the two-sided slide  806  is actuated—from the left-hand side in  FIG. 10 , the two-sided slide  806  is displaced, by way of illustration, to the right into the second of the two switching positions  930 . In this second of the two switching positions  930 , the spring element  820  is preferably tensioned between the first projection  901  of the two-sided slide  806  and the second projection  904  of the housing part  905 . After the two-sided slide  806  has been actuated, the spring element  820  therefore makes it possible for the two-sided slide  806  to independently return to the position of rest  920  from the switching position  930 . 
       FIG. 11  shows another exemplary operating element which is designed as a monostable switching element and is in the form of a slide  1106 . By way of illustration, the slide  1106  can be linearly displaced along an associated device longitudinal axis of the hand-held power tool  100  from  FIG. 1 . By way of illustration, the slide  1106  is in a stable position of rest  1107 . If the slide  1106  is actuated, the latter is preferably displaced from the position of rest  1107  into an associated switching position  1108 . The slide  1106  is preferably assigned a sensor unit ( 1370  in  FIG. 15 ) which is designed to generate a corresponding actuation signal when the slide  1106  is actuated. The actuation signal can preferably be evaluated in order to determine a respectively current direction of rotation of the output spindle ( 310  in  FIG. 3 ). For this purpose, the sensor unit  1370  preferably has a mechanical, electrical, magnetic and/or optical sensor. By way of illustration, the slide  1106  can generate a corresponding actuation signal in the sensor unit  1370  when actuated via a pressure piece  1111 . 
     The stable position of rest  1107  of the slide  1106  is preferably the front position and the unstable switching position is preferably the rear position. Alternatively, the rear position can also be the stable position of rest and the front position can be the unstable switching position. According to one embodiment, the slide  1106  has a position of rest and two switching positions, wherein the first of the two switching positions is provided upstream of the position of rest and the second of the two switching positions is provided downstream of the position of rest. The slide  1106  preferably has at least one spring element  1110  which, by way of illustration, makes it possible for the slide  1106  to return to a position of rest  1107  from a switching position  1108  after the slide has been actuated. 
       FIG. 12  shows the hand-held power tool  100  from  FIG. 1  with the user guidance unit  115  from  FIG. 1  which here preferably has an operating unit  1020  for manually setting a gear or an operating mode and/or a direction of rotation. The operating unit  1020  is preferably provided with at least one operating element, by way of illustration three operating elements  1021 ,  1022 ,  1023 , for setting a gear or an operating mode and with, by way of illustration, two operating elements  1085 ,  1086  for initiating a changeover operation for changing over the drive unit ( 220  in  FIG. 2 ) between the first direction of rotation and the second direction of rotation. By way of illustration, the operating element  1021  is provided for the purpose of setting the screwing mode, the operating element  1022  is provided for the purpose of setting the drilling mode and the operating element  1023  is provided for the purpose of setting the percussion mode, wherein the operating elements  1021 - 1023  have, by way of example, symbols or pictograms corresponding to the operating modes. 
     By way of illustration, the operating element  1085  is provided for the purpose of setting a rotation of the drive unit  220  in the clockwise direction and the operating element  1086  is provided for the purpose of setting a rotation of the drive unit  220  in the anticlockwise direction. The operating elements  1085 ,  1086  are each preferably in the form of monostable switching elements and have, for example, symbols or pictograms corresponding to the direction of rotation. The operating elements  1021 - 1023  and  1085 ,  1086  are preferably arranged on a printed circuit board  1030 . In this case, the operating unit  1020  is preferably at least partially integrated in the hand-held power tool  100 . 
       FIG. 13  shows an operating unit  1120  having at least one operating element, by way of illustration three operating elements  1021 ,  1022 ,  1023 , for setting a gear or an operating mode and having, by way of illustration, an operating element  1180  for initiating a changeover operation for changing over the drive unit ( 220  in  FIG. 2 ) between the first direction of rotation and the second direction of rotation. According to one embodiment, the operating unit  1120  has a touch-sensitive screen. 
     By way of illustration, the operating element  1021  is provided for the purpose of setting the screwing mode, the operating element  1022  is provided for the purpose of setting the drilling mode and the operating element  1023  is provided for the purpose of setting the percussion mode, wherein the operating elements  1021 - 1023  have, for example, symbols or pictograms corresponding to the operating modes. By way of illustration, the operating element  1180  is provided for the purpose of changing over the drive unit ( 220  in  FIG. 2 ) between a first direction of rotation and a second direction of rotation and is preferably in the form of a monostable switching element. The indications  1185 ,  1186  have, for example, symbols or pictograms corresponding to the direction of rotation. The operating elements  1021 - 1023  and  1180  are preferably arranged on a printed circuit board  1030 . In this case, the operating unit  1020  is preferably at least partially integrated in the hand-held power tool  100  from  FIG. 1 . 
       FIG. 14  shows a section of the operating unit  1120  from  FIG. 13  with the operating element  1180  and the printed circuit board  1030 . At least two indications  1185 ,  1186  are preferably provided on the operating unit  1120  for the purpose of indicating a respectively set direction of rotation. The indication  1185  preferably indicates a rotation of the output spindle ( 310  in  FIG. 3 ) in the anticlockwise direction and the indication  1186  indicates a rotation of the output spindle  310  in the clockwise direction. 
     The printed circuit board  1030  preferably has at least one switching element  1235  assigned to the operating element  1180  and at least two illumination means  1231 ,  1233  assigned to the indications  1185 ,  1186 . The illumination means  1231 ,  1233  are preferably at least designed to indicate a request to initiate a changeover operation for changing over the drive unit  220  between the first direction of rotation and the second direction of rotation when predefined operating conditions occur. 
     The switching element  1235  is preferably in the form of a monostable switch, by way of illustration in the form of a pushbutton, and/or the illumination means  1231 ,  1233  are in the form of LEDs. Alternatively or additionally, the operating unit  1120  can also be in the form of a display, preferably with a touch-sensitive screen, which is sometimes also referred to as a touchscreen, and/or a mobile computer, wherein a symbol to be respectively actuated can respectively light up and/or flash on the display. Alternatively, it is also possible to implement gesture recognition. The operating unit  1120  is preferably connected to the actuating motor  182  and to the actuating motor transmission  184  for the purpose of setting a direction of rotation selected by a user  1230 , which can in turn preferably rotate the direction of rotation detection unit  160  about a shaft  762 . 
       FIG. 15  shows a schematic tool system  1000  having the hand-held power tool  100  described above and a mobile computer  1040 . In this case,  FIG. 15  illustrates the hand-held power tool  100  with its drive unit  220  having the drive motor  120 , the transmission  130 , the optional percussion mechanism  320  and the torque limitation element  170 . In this case, the control electronics  150  control at least one actuator  1351 ,  1352 , and  1353 . By way of illustration,  FIG. 15  illustrates three actuators  1351 ,  1352 ,  1353 , wherein the actuator  1351 , for example, is designed to change over the gear of the transmission  130  and/or to change over the transmission  130  between the first direction of rotation and the second direction of rotation, the actuator  1352  is designed to activate/deactivate the optional percussion mechanism  320  and the actuator  1353  is designed to set a torque by means of the torque limitation element  170 . The control electronics  150  preferably forward an activation signal to an assigned illumination means  1231 ,  1233  when an actuator  1351 - 1353  is activated. Alternatively or additionally, the activation signal may also be in the form of a signal tone. 
     According to one embodiment, the mobile computer  1040  has an interactive program  1342 ,  1344 , in particular a smartphone app, for communicating with the communication interface  1050  of the hand-held power tool  100 . In this case, a first program  1342  is preferably designed to set applications, for example in order to screw a screw into softwood. In this case, the program  1342  determines operating parameters, for example a speed, a direction of rotation, a torque, a gear and/or a percussion operation requirement, preferably for a respective application, and forwards said parameters to the communication interface  1050  of the hand-held power tool  100 . 
     Alternatively, the interactive program  1342 ,  1344  may also be assigned only to the communication interface  1050  of the hand-held power tool  100 . In this case, the interactive program  1342 ,  1344  is preferably executed by the communication interface  1050  of the hand-held power tool  100 , with the result that it is possible to dispense with use of the mobile computer  1040 . 
     In this case, the communication interface  1050  is preferably designed to transmit a control signal to the actuators  1351 ,  1352 ,  1353  of the hand-held power tool  100 , wherein at least one actuator  1351  is designed to change over the transmission  130  between the different gears when activated by the communication interface  1050 . 
     In this case, the communication interface  1050  preferably transmits the control signal to the control electronics  150  which activate and/or control the respective actuators  1351 - 1353 . 
     Alternatively or additionally, a second program  1344  is provided and is designed to set at least one particular operating parameter, for example a speed, a direction of rotation, a torque, a gear and/or a percussion operation requirement. In this case, a user of the hand-held power tool  100  inputs desired operating parameters directly via the program  1344 . These parameters are then transmitted to the communication interface  1050  of the hand-held power tool  100 , wherein the communication interface  1050  forwards a corresponding control signal, as described above. 
     Alternatively or additionally, the hand-held power tool  100  can have at least one operating element  106 ,  1311 ,  1312 ,  1313  for the purpose of initiating a changeover operation for changing over the drive unit ( 220  from  FIG. 2 ) or the drive motor  120  or the transmission  130  between the first direction of rotation and the second direction of rotation, for the purpose of manually setting a gear and/or an operating mode or for the purpose of manually setting operating parameters. By way of illustration,  FIG. 15  shows four operating elements  106 ,  1311 ,  1312 ,  1313 . In this case, the first operating element  106 , for example, is designed to initiate the changeover operation for changing over the drive unit  220  between the first direction of rotation and the second direction of rotation, the second operating element  1311  is designed to change over the gear, the third operating element  1312  is designed to activate and/or deactivate the optional percussion mechanism  320  and the fourth operating element  1313  is designed to set the torque. 
     The respective operating element  106 ,  1311 ,  1312 ,  1313  is preferably designed to transmit a control signal to the control electronics  150  in an application-specific manner or depending on the input, with the result that the control electronics  150  can directly activate and/or control the respective actuators  1351 - 1353  and/or the drive motor  120 . In this case, the operating element  106  is preferably in the form of a monostable switch, for example in the form of a switching rocker ( 406  in  FIG. 4 ), a slide ( 706  in  FIG. 8 ) or a pushbutton ( 1235  in  FIG. 14 ). The operating elements  1311 - 1313  are preferably in the form of electrical operating elements, but may also be in the form of any other desired operating element, for example in the form of a mechanically displaceable lever arm. 
     In addition, the user guidance unit  115  may be assigned a display and/or a mobile computer  1040  which indicates changeover instructions for changing over the drive motor ( 120  in  FIG. 2 ) or the output spindle ( 310  in  FIG. 3 ), which can be at least indirectly driven by the drive motor, between the first direction of rotation and the second direction of rotation and/or changeover instructions for changing over the drive motor  120  or the transmission  130  in an application-specific manner. In this case, the respective changeover instructions can be visualized on the display and/or the mobile computer  1040  as step-by-step instructions. In this case, the at least one operating element  116 ,  117  is preferably assigned a sensor unit  1370  which is designed to transmit an actuation signal to the communication interface  1050  and/or to the mobile computer  1040  if the at least one operating element  116 ,  117  is actuated, with the result that a next step of the respective changeover instruction can be respectively indicated. 
     Furthermore, the sensor unit  1370  may also be in the form of an internal and/or external sensor for monitoring and/or optimizing the hand-held power tool  100  and may preferably be in the form of a temperature sensor, an acceleration sensor, a position sensor etc. In this case, it is possible to provide software which is designed to check the settings of the control electronics  150  or of the hand-held power tool  100  and to adapt them if necessary, for example to output a warning signal and/or to automatically change over the gear if the drive motor  120  from  FIG. 1  has become hot on account of an excessively high applied torque. 
     An adapter interface  1380  is preferably provided for the purpose of connection to at least one adapter  1385 . In this case, the adapter interface  1380  can be in the form of a mechanical interface, an electrical interface and/or a data interface, wherein the adapter  1385  is designed to transmit information and/or control signals, for example a torque, a speed, a voltage, a current and/or further data, to the hand-held power tool  100 . The adapter  1385  in an adapter interface  1380  in the form of a data interface preferably has a transmission unit. The adapter  1385  can preferably be in the form of a distance meter, for example, and can pass determined parameters to the hand-held power tool  100  via the adapter interface  1380 . In this case, the adapter can be used with and/or without the drive unit  220 . The adapter  1385  can preferably be activated via the mobile computer  1040 , in which case the latter or the display can visualize activation of the adapter  1385 . 
     The control electronics  150  preferably also control the drive motor  120  and/or the working field illumination  104 . The manual switch  105  preferably has a locking mechanism  1360  which is preferably in the form of a mechanical and/or electrical locking mechanism. Furthermore, the on/off switch  107  and/or the control electronics  150  is/are supplied with power by the rechargeable battery pack  102 . 
       FIG. 16  shows the hand-held power tool  100  from  FIG. 1  with the drive unit  220  from  FIG. 2  which can be changed over between the first direction of rotation and the second direction of rotation, wherein the hand-held power tool  100  according to one embodiment has the switching rocker  406  from  FIG. 4  and the communication interface  1050  from  FIG. 1 . In addition, the hand-held power tool  100  is provided with the user guidance unit  115  from  FIG. 1  which here preferably has the operating unit  1120  from  FIG. 13  for manually setting a reversal of the direction of rotation. 
     The operating unit  1120  is preferably provided with at least one operating element  1180  for initiating a changeover operation for changing over the drive unit ( 220  in  FIG. 2 ) between the first direction of rotation and the second direction of rotation. By way of illustration, the operating element  1180  is provided for the purpose of changing over the drive unit ( 220  in  FIG. 2 ) between the first direction of rotation and the second direction of rotation and is preferably in the form of a monostable switching element. In this case, the operating unit  1020  is preferably at least partially integrated in the hand-held power tool  100 . 
     In this case or alternatively, the user guidance unit  115  can be at least partially in the form of an external separate component  1040 , as described above. In this case, the external component  1040  preferably has a mobile computer, in particular in the form of a smartphone and/or a tablet computer. Alternatively, other so-called “smart devices”, for example a watch, glasses etc., can also be used as the mobile computer. In this case, it is also possible to dispense with providing the operating unit  1120 , as described above, in particular if the operating unit can be implemented by the mobile computer  1040 . In order to indicate an operating mode which has been set, the hand-held power tool  100  preferably has a display. The user guidance unit  115  preferably forms, with the hand-held power tool  100 , a tool system  1000  in this case. 
     The mobile computer  1040  preferably has a display  1010  which is preferably in the form of a touchscreen. The display  1010  preferably has at least one operating element  1015  at least for reversing the direction of rotation of the output spindle ( 310  in  FIG. 3 ) of the hand-held power tool  100  and at least two indication elements  1014  and  1016  for indicating the currently set direction of rotation. Alternatively or additionally, the at least two indications  1014 ,  1016  are formed on the display  1010  as operating elements for determining the direction of rotation of the output spindle  310 . Furthermore, the display  1010  preferably has at least one operating element, by way of illustration three operating elements  1011 ,  1012 ,  1013 , for inputting at least one operating mode of the hand-held power tool  100 . By way of illustration, the operating elements  1011 - 1016  are in the form of operating panels on the display  1010  in  FIG. 16 , but could also be in the form of switches and/or buttons. 
     According to one embodiment, the hand-held power tool  100  is designed in such a manner that the output spindle  310  from  FIG. 3  assumes a preprogrammed first direction of rotation under particular conditions, for example after an interrupted power supply caused by changing a rechargeable battery pack  102 . The operating elements  106 ,  1015 ,  1180  are preferably designed to make it possible to reprogram the hand-held power tool  100 , as a result of which the preprogrammed first direction of rotation is at least reversed. The reprogramming is preferably carried out by actuating the operating elements  106 ,  1015 ,  1180  in a predetermined sequence. Actuation of the operating elements  106 ,  1015 ,  1180  in another predetermined sequence preferably makes it possible to block the hand-held power tool  100 . 
     In the event of the user guidance unit  115  having both the operating unit  1120  and the mobile computer  1040 , the above-described control signal is preferably designed to generate an indication on the display  1010  for requesting the initiation of a changeover operation for changing over the transmission  130  between the different gears and/or to generate an indication for requesting the initiation of a changeover operation for changing over the drive unit ( 220  in  FIG. 2 ) between the first direction of rotation and the second direction of rotation and/or to make it possible to initiate the changeover operation. 
     In this case, changeover instructions are preferably indicated using the display  1010 , for example an instruction relating to which direction of rotation is intended to be set for a predefined work process, which direction of rotation can then be set by a user of the hand-held power tool  100 , for example via the operating unit  1120 . In this case, the indications  1185 ,  1186  on the hand-held power tool  100  can be provided with illumination means ( 1231 ,  1233  in  FIG. 14 ) and the control signal is designed in this case to respectively activate a corresponding illumination means  1231 ,  1233 . 
     In addition, the mobile computer  1040  can also be at least partially integrated in the hand-held power tool  100  and the operating mode is preferably respectively set automatically, preferably via the actuating unit  180 . It is pointed out that the exemplary implementations of the user guidance unit  115  which are described in  FIG. 16  can be combined with one another as desired and the communication interface  1050 , for example, can also undertake the functionality of the user guidance unit  115 . 
       FIG. 17  shows a flowchart for initiating a changeover operation for changing over a drive unit ( 220  in  FIG. 2 ) of a hand-held power tool ( 100  in  FIG. 1 ) between a first direction of rotation and a second direction of rotation, wherein a user guidance unit ( 115  in  FIG. 1, 1040  in  FIG. 16 ) which can be actuated by a user is provided and is designed to transmit changeover instructions for changing over the drive unit  220  between the first direction of rotation and the second direction of rotation in an application-specific manner to a communication interface ( 1050  in  FIG. 1 ). In this case, the user guidance unit  115 ,  1040  is preferably at least partially integrated in the hand-held power tool  115 ,  100  and/or is at least partially in the form of an external separate component  1040 . The user guidance unit  115 ,  1040  preferably has a mobile computer  1040 , in particular a mobile computer in the form of a smartphone or a tablet computer. 
     Alternatively, other so-called “smart devices”, for example a watch, glasses etc., can also be used as the mobile computer. 
     The user guidance unit  115 ,  1040  preferably has an interactive program  1342 ,  1344 , in particular a smartphone app, for communicating with the communication interface  1050 . Alternatively or additionally, it is possible to interact with the interactive program, preferably via a user guidance unit  115  in the form of an operating element  1120 . 
     The user guidance unit  115 ,  1040  also preferably has at least one operating element  106  for initiating a changeover operation for changing over the drive unit  220  between the first direction of rotation and the second direction of rotation, wherein the communication interface  1050  is designed to transmit a control signal to the at least one operating element  106  in order to make it possible for the at least one operating element  106  to generate a request to initiate a changeover operation for changing over the drive unit  220  between the first direction of rotation and the second direction of rotation. 
     The at least one operating element  106  preferably has a display  1010  and the control signal is preferably designed to generate an indication on the display  1010  for visualizing the request to initiate a changeover operation for changing over the drive unit  220  between the first direction of rotation and the second direction of rotation. In this case, the display  1010  is preferably in the form of a touchscreen. 
     According to one embodiment, an interactive program  1342 ,  1344  becomes active in step  1701  with establishment of the power supply—for example after the electrical connection of a rechargeable battery pack ( 102  in  FIG. 1 ) which is in a charged state—with the hand-held power tool  100 . Alternatively or additionally, an interactive program  1342 ,  1344  can be activated by touching the display  1010 . After the interactive program  1342 ,  1344  has been activated, the drive unit  220  preferably assumes a preprogrammed first direction of rotation, preferably a rotation of the drive unit  220  in the clockwise direction. 
     In step  1702 , the interactive program  1342 ,  1344  identifies a desired changeover operation for changing over the drive unit  220 . If the interactive program  1342 ,  1344  identified a first changeover operation in step  1702 , which corresponds to response A to test  1703 , the interactive program  1342 ,  1344  continues with the first changeover operation in step  1704 . If the interactive program  1342 ,  1344  identified a second changeover operation in step  1702 , which corresponds to response B to test  1703 , the interactive program  1342 ,  1344  continues with the second changeover operation in step  1708 . 
       FIG. 18  shows a flowchart of the first changeover operation  1704  from  FIG. 17 . In step  1801 , the interactive program  1342 ,  1344  preferably monitors the at least one operating element  106 , preferably via the sensor unit  1370  from  FIG. 15  which preferably has a mechanical, electrical, magnetic and/or optical sensor. In step  1803 , the interactive program  1342 ,  1344  captures a movement of the operating element  106  from a stable position of rest ( 510  in  FIG. 5 ) into an unstable switching position ( 520  in  FIG. 5 ) caused, for example, by the actuation of the operating element  106  by a user ( 1230  in  FIG. 14 ). 
     In step  1805 , after the operating element  106  has been actuated by the user  1230 , the interactive program  1342 ,  1344  captures a movement of the operating element  106  from the unstable switching position  520  back into the stable position of rest  510 , preferably caused by at least one spring element ( 610  in  FIG. 6 ). In step  1807 , the interactive program  1342 ,  1344  monitors the status of the drive motor  120  and continues with step  1820  if the drive motor  120  is not operating, which corresponds to response A to test  1810 . If the drive motor  120  is operating, which corresponds to response B to test  1810 , the interactive program  1342 ,  1344  continues with step  1830 . 
     In test  1830 , the interactive program  1342 ,  1344  tests whether a changeover operation for changing over the drive unit  220  between the first direction of rotation and the second direction of rotation is allowed if the drive motor  120  is operating. If the changeover operation is not allowed (response D), a changeover operation is not carried out in step  1850  and the interactive program  1342 ,  1344  continues with step  1801 . If the changeover operation is allowed, which corresponds to response C to test  1830 , the interactive program  1342 ,  1344  continues with step  1840 , during which the drive motor  120  is braked to a standstill. 
     If the drive motor  120  is not operating or is at a standstill, the interactive program  1342 ,  1344  causes a changeover operation for changing over the drive unit  220  between the first direction of rotation and the second direction of rotation in step  1820 . If the drive unit  220  was driven in the clockwise direction, for example, before step  1820 , the drive unit  220  is driven in the anticlockwise direction after step  1820 . If the drive unit  220  was driven in the anticlockwise direction, for example, before step  1820 , the drive unit  220  is driven in the clockwise direction after step  1820 . Furthermore, the interactive program  1342 ,  1344  in step  1820  preferably controls an indication—for example indication  1014 ,  1016  on the display  1010  in  FIG. 16  and/or indication  1185 ,  1185  on operating unit  1120  in  FIG. 14 —for indicating the current direction of rotation of the output spindle  310  from  FIG. 3 . 
     After the changeover operation has been completed, the interactive program  1342 ,  1344  continues with step  1822 , during which the interactive program  1342 ,  1344  preferably makes it possible to activate the drive motor  120  again and returns to step  1801 . 
       FIG. 19  shows a flowchart of the second changeover operation  1708  from  FIG. 17 . In step  1901 , the interactive program  1342 ,  1344  sets a preferred direction of rotation of the drive unit ( 220  in  FIG. 2 ). The preferred direction of rotation is preset as a rotation in the clockwise direction, for example. Alternatively or additionally, the preferred direction of rotation can be programmed by the user ( 1230  in  FIG. 14 ). 
     In step  1902 , the interactive program  1342 ,  1344  preferably monitors the at least one operating element  106 , preferably via a sensor unit ( 1370  in  FIG. 15 ) which preferably has a mechanical, electrical, magnetic and/or optical sensor. If the interactive program  1342 ,  1344  captures a movement of the operating element  106  from a stable position of rest ( 510  in  FIG. 5 ) into an unstable switching position ( 520  in  FIG. 5 ), preferably via the sensor unit  1370 , which corresponds to response A to test  1910  and can be carried out, for example, by a user  1230  actuating the operating element  106 , the interactive program  1342 ,  1344  continues with step  1930 . If the interactive program  1342 ,  1344  does not capture a movement of the operating element  106  from a stable position of rest ( 510  in  FIG. 5 ) into an unstable switching position ( 520  in  FIG. 5 ), which corresponds to response B to test  1910 , the interactive program  1342 ,  1344  continues with test  1920 . 
     If the interactive program  1342 ,  1344  captures a movement of the operating element  106  from the unstable switching position  520  back into the stable position of rest  510 , preferably via the sensor unit  1370 , which corresponds to response C to test  1920  and is preferably enabled by means of at least one spring element ( 610  in  FIG. 6 ), the interactive program  1342 ,  1344  continues with step  1930 . If the interactive program  1342 ,  1344  does not capture a movement of the operating element  106  from an unstable switching position  520  into a stable position of rest  510 , which corresponds to response D to test  1920 , the interactive program  1342 ,  1344  returns to step  1902 . 
     In step  1930 , the interactive program  1342 ,  1344  monitors the status of the drive motor  120  and continues with test  1960  if the drive motor  120  is not operating, which corresponds to response E to test  1940 . If the drive motor  120  is operating, which corresponds to response F to test  1940 , the interactive program  1342 ,  1344  continues with step  1950 . 
     In step  1950 , the interactive program  1342 ,  1344  preferably causes braking of the drive motor  120  to a standstill. If the drive motor  120  is not operating or is at a standstill, the interactive program causes a changeover operation for changing over the drive unit  220  between the first direction of rotation and the second direction of rotation in step  1970 . If the drive unit  220  was driven in the clockwise direction, for example, before step  1970 , the drive unit  220  is driven in the anticlockwise direction after step  1970 . If the drive unit  220  was driven in the anticlockwise direction, for example, before step  1970 , the drive unit  220  is driven in the clockwise direction after step  1970 . The interactive program also preferably controls in step  1970  an indication—for example indication  1014 ,  1016  on the display  1010  in  FIG. 16  and/or indications  1185 ,  1185  on operating unit  1120  in  FIG. 14 —for indicating the current direction of rotation of the output spindle  310  from  FIG. 3 . 
     After the changeover operation has been completed, the interactive program continues with step  1990 , during which the interactive program  1342 ,  1344  preferably makes it possible to activate the drive motor  120  again and returns to step  1902 .