Abstract:
An electric switch, in particular for an electric power tool, in particular a hammer drill, comprises a first switching device and a second switching device, wherein the first switching device can be adjusted by adjusting a first mechanical signaling means from a first switched state to a second switched state, wherein the second switching device can be adjusted by adjusting a second electrical or mechanical signaling means from a third switched state in which the electric switch acts as a pushbutton into a fourth switched state in which the switch acts as a rocker switch. The disclosure further relates to an electrical power tool having an electric switch according to the disclosure.

Description:
This application is a 35 U.S.C. §371 National Stage Application of PCT/EP2011/070288, filed on Nov. 16, 2011, which claims the benefit of priority to Serial No. DE 10 2010 063 962.1, filed on Dec. 22, 2010 in Germany, the disclosures of which are incorporated herein by reference in their entirety. 
     BACKGROUND 
     The present disclosure relates to an electric switch, in particular for an electric power tool, in particular a hammer drill or a chipping hammer, which electric switch comprises a first switching device and a second switching device, wherein the first switching device can be adjusted by means of adjusting a first mechanical signal means from a first switching mode into a second switching mode. The present disclosure further relates to an electric power tool having an electric switch in accordance with the disclosure. 
     It is known for electric power tools, in particular for hammer drills or chipping hammers, to damp vibrations in the hand grip by means of providing an elastic element between the hand grip and the tool housing of the electric power tool. Hand grips of this type are also described as anti-vibration hand grips. The elastic element enables the hand grip to move relative to the tool housing in a horizontal and/or vertical direction. An electric power tool having an elastic element of this type is disclosed in WO 2008/000543 A1. 
     DE 10 2008 041 511 A1 illustrates a handheld power tool that comprises an electric switch and a mechanical adjusting device that is arranged on the electric switch and is embodied in this case as a rocker switch. The electric switch can be actuated by means of the rocker switch. The rocker switch can be locked in an operating mode of the machine by means of a locking device. In the case of hammer drills, in order to increase the level of comfort for the user, the rocker switch is for example frequently locked in the “chipping operation”, so that the operator does not need to constantly hold down the switch in this operating mode. However, the rocker switch cannot be locked in the “drilling” or “hammer drill operation”, so that the electric power tool can be switched off as quickly as possible by the operator in the event of the drill tilting and said drill cannot rotate in an uncontrolled manner and consequently it cannot therefore injure the operator. 
     However, it is extremely difficult to implement the locking function in the case of anti-vibration hand grips since an operating mode switch is conventionally arranged on the tool housing and a relative movement of several millimeters can occur between the hand grip housing and the tool housing. In addition, a locking of this type requires a mechanical deflection between the operating mode switch and the locking action of the rocker switch. Furthermore, an on/off switch of this type requires a considerable amount of installation space and the higher the power rating of the electric power tool, the greater the installation space. 
     DE 100 34 768 A1 discloses for example a high-performance hammer drill, wherein the operating mode switch is rigidly coupled to a locking device for a switching latch. However, this rigid coupling arrangement does not allow the hand grip housing to be fully decoupled from the tool housing with regard to the vibrations of a tool housing of the electric power tool. In addition, the lever mechanism required for coupling the locking device to the operating mode switch requires considerable installation space. Furthermore, the locking device is also not dustproof. 
     SUMMARY 
     The object of the present disclosure is to provide a particularly high-performance electric power tool that is operated in at least one operating mode without an actuating means for driving the electric power tool having to be permanently actuated, wherein the hand grip can be embodied as an anti-vibration hand grip that can be fully decoupled from the tool housing, and wherein the hand grip is embodied in an extremely compact and stable manner. A further object of the disclosure is to improve the level of protection to prevent dust penetrating into the anti-vibration device. 
     The object is achieved by means of an electric switch, in particular for an electric power tool, in particular a hammer drill or a chipping hammer, which electric switch comprises a first switching device and a second switching device, wherein the first switching device can be reversibly adjusted by means of adjusting a first mechanical signal means from a first switching mode into a second switching mode, wherein the second switching device can be reversibly adjusted by means of adjusting a second electric or mechanical signal means from a third switching mode in which the electric switch functions as a push button into a fourth switching mode in which said electric switch functions as a rocker switch. 
     In the case of a push button in terms of the disclosure, the electric switch returns automatically from the second switching mode into the first switching mode. It is preferred in this case that the electric switch is adjusted against the restoring force of a first force means from the first switching mode into the second switching mode, so that said electric switch is automatically returned to its previous position by means of the restoring force of the first force means. 
     In the case of a rocker switch in terms of the disclosure, the electric switch does not automatically return from the second switching mode into the first switching mode but rather remains in the second switching mode. 
     It is therefore preferred that the switch in accordance with the disclosure in the fourth switching mode, in which it functions as a rocker switch, is either locked or at least can be locked. In the framework of  FIGS. 1-6 , the fourth switching mode is therefore described as the locked mode. 
     The electric switch can therefore itself be locked or is locked. In comparison to a conventional device, in which a mechanical adjusting device for actuating a conventional electric switch can be locked by means of a separate locking device, an electric switch in accordance with the disclosure can be constructed in a considerably more compact manner and thus renders it possible for it to be positioned in a considerably less restrictive manner in an electric power tool and by reason of less installation space being required a compact embodiment of the electric power tool is achieved. 
     It is preferred that the second switching mode is a switched-on mode in which the electric switch closes a current circuit, in particular a motor current circuit for driving the electric power tool and that the first switching mode is a switched-off mode in which the current circuit is open. Depending upon the particular application, an embodiment is however also preferred in which the first switching mode is the switched-on mode and the second switching mode is the switched-off mode, so that the electric switch automatically returns from the switched-off mode into the switched-on mode. 
     It is further preferred that the electric switch is adjusted against the restoring force of a second force means from the third switching mode into the locked mode, so that said electric switch is returned by means of the restoring force of the second force means from the locked mode into the third switching mode. Depending upon the particular application, an embodiment is however also preferred in which the electric switch is adjusted against the restoring force of the second force means from the locked mode into the third switching mode, so that said electric switch is returned by means of the restoring force of the second force means from the third switching mode into the locked mode. 
     In a particularly preferred embodiment, the electric switch is adjusted against the restoring force of the second force means from the third switching mode into the locked mode, wherein said electric switch is adjusted against the force of the first force means from the switched-off mode into the switched-on mode. In this preferred embodiment, the third switching mode is an initial mode of the electric switch and the electric switch for example can be used as a motor switch for driving the electric power tool. 
     It is preferred that the first switching device comprises an electrical contact and electrical connections for closing the current circuit. The electrical contact is preferably provided in order not to connect the electrical connections in the switched-off mode so that the current circuit is open, and in order to connect the electrical connections in the switched-on mode so that the current circuit is closed. 
     It is further preferred that the electric switch comprises a housing. In this case, it is particularly preferred that only the first and second signal means and the electric connections are arranged partially outside the housing so that they are accessible from the outside. As a consequence, the switch is protected against external influences, for example, to prevent the penetration of dust and moisture. In an advantageous manner, the switch of this embodiment can be manufactured as a single-module component so that it can be mounted in a cost-effective manner and can be used for electric power tools of different types. 
     In a preferred embodiment, the first switching device comprises also a first adjusting means that cooperates with the first signal means, wherein the electrical contact can be adjusted by means of the first adjusting means. As the first signal means is adjusted, the first adjusting means is adjusted, so that the electrical contact is adjusted from the switched-off mode into the switched-on mode and the reverse. The first switching means is preferably provided as a sliding means or as a rotating means. 
     In a further preferred embodiment, the second switching device comprises a second adjusting means that cooperates with the second signal means, wherein the first signal means and/or the first adjusting means can be locked or are locked in the locked mode by means of the second adjusting means. As the second signal means is adjusted, the second adjusting means is therefore preferably adjusted in such a manner that it prevents the movement of the first signal means and/or of the first adjusting means. The second adjusting means is likewise preferably embodied as a sliding means or as a rotating means. 
     In this preferred embodiment, the first signal means and/or the first adjusting means can be locked in the switched-off mode and are locked in the switched-on mode by means of adjusting the second adjusting means. 
     Furthermore, in this preferred embodiment, the first signal means and/or the first adjusting means cannot be locked or are not locked in the initial mode by means of the second adjusting means. The electric switch in this embodiment therefore only remains in the locked mode in the switched-on mode. In every other mode, said electric switch is located either in the switched-off mode or it returns automatically to the switched-off mode. It is therefore necessary for the operator to purposefully adjust the switch in order to remain in the switched-on mode. This embodiment ensures the maximum possible reliability concerning the prevention of the current circuit being unintentionally switched on. 
     The first signal means can preferably be actuated by means of a first actuating means and the second signal means can likewise preferably be actuated by means of a second actuating means. The first and the second signal means therefore represent the interface, by means of which the electric switch can be actuated and switched between its different switching modes. 
     In a preferred embodiment, the first signal means and/or the first adjusting means and/or the first actuating means are embodied in a mechanical manner. In this embodiment, the first signal means can preferably be actuated by means of the first actuating means, it can in particular be rotated or displaced, wherein the first adjusting means can be adjusted by means of the first signal means from the switched-off position into the switched-on position or the reverse, it can in particular be rotated or displaced. It is particularly preferred that the first signal means is embodied as an angled lever, wherein the first adjusting means is preferably embodied as a sliding means, and wherein the first actuating means is preferably embodied as a rocker switch. The angled lever can then be actuated preferably by means of the rocker switch, in particular said angled lever can be rotated, wherein the sliding means can be displaced by means of the angled lever from the switched-off position into the switched-on position or the reverse. 
     The rocker switch is preferably rotatably mounted on the switch housing of the electric switch. In this embodiment, the rocker switch preferably comprises a first rocker switch part and a second rocker switch part, wherein the electric switch can be adjusted by means of actuating the first rocker switch part into the switched-on mode and by actuating the second rocker switch part into the switched-off mode. 
     In a further preferred embodiment, the second signal means and/or the second adjusting means and/or the second actuating means are provided in a mechanical manner. In this embodiment, the second signal means can be preferably actuated by means of the second actuating means, it can in particular be rotated or displaced, wherein the second adjusting means can be adjusted by means of the second signal means from the switched-off position into the switched-on position or the reverse, it can in particular be rotated or displaced. It is particularly preferred that the second signal means is embodied as a switching lever, wherein the second adjusting means is preferably embodied as a locking latch, and wherein the second actuating means is preferably embodied as a switching connection, in particular as a pulling means or as a Bowden cable. The switching lever can then be actuated preferably by means of the switching connection; it can in particular be rotated, wherein the locking latch can be rotated by means of the angled lever from the initial position into the locked position or the reverse. 
     The locking latch is preferably mounted on the switching lever and in the locked mode cooperates with the sliding means. For this purpose, the sliding means likewise preferably comprises a blocking means that in the locked mode lies against the locking latch, so that the sliding means is locked in the switched-on mode and can no longer be displaced. As a consequence, it is not possible for the sliding means, and consequently also the angled lever to automatically return to the initial position by means of the restoring force of the first force means. 
     It is likewise preferred that the second signal means and/or the second adjusting means and/or the second actuating means are provided in an electric, electronic or electromagnetic manner. The second signal means is then preferably a Tipp-signal that is triggered, for example, by means of being keyed again or by means of a another signal being triggered by the operator, in particular an operating mode switch of the electric power tool, which operating mode switch is embodied, for example, in an electric manner. In this embodiment, the second adjusting means is preferably likewise adjusted electrically, for example with the aid of a relay. 
     Fundamentally, an embodiment is also possible in which the first signal means and/or the first adjusting means and/or the first actuating means are provided in an electric manner. 
     The object is further achieved by means of an electric power tool, in particular a hammer drill or a chipping hammer having an electric switch in accordance with the disclosure. 
     Since the electric switch in accordance with the disclosure can be produced in a considerably compact manner irrespective of the power rating of the electric power tool, there is either more available installation space in the electric power tool or said electric power tool can likewise be constructed in a more compact manner. 
     In a preferred embodiment, the electric switch and the first actuating means are arranged in a hand grip housing, in particular in an anti-vibration hand grip housing, wherein the electric power tool comprises an operating mode switch for adjusting the second actuating means, which means is arranged in a tool housing. 
     In this embodiment, the hand grip housing of the electric power tool can be produced in a more compact manner so that the electric power tool can be handled in a simpler manner. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Hereinunder, the disclosure is described with reference to the figures. The figures are only examples and do not limit the general concept of the disclosure. 
         FIG. 1  illustrates an electric power tool having a hand grip housing that is embodied as an anti-vibration hand grip housing, wherein the electric power tool comprises an electric switch in accordance with the disclosure, 
         FIG. 2  illustrates a section of the electric power tool shown in  FIG. 1  and in fact (a) is a perspective view and (b) is a lateral sectional view, 
         FIG. 3  illustrates in  FIGS. 3 ( a )-( c )  the electric switch in accordance with the disclosure of the electric power tool shown in  FIG. 1 , wherein the electric switch comprises a first switching device and a second switching device, and where the first switching device is located in the switched-off mode and the second switching device is located in the initial mode, 
         FIG. 4  illustrates in  FIGS. 4 ( a )-( c )  the electric switch shown in  FIG. 3 , wherein the first switching device is located in the switched-on mode and the second switching device is located in the initial mode, 
         FIG. 5  illustrates in  FIGS. 5 ( a )-( c )  the electric switch shown in  FIG. 3 , wherein the first switching device is located in the switched-off mode and the second switching device is located in the locked mode, 
         FIG. 6  illustrates in  FIGS. 6 ( a )-( c )  the electric switch shown in  FIG. 3 , wherein the first switching device is located in the switched-on mode and the second switching device is located in the locked mode. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates an electric power tool  1  in accordance with the disclosure having a hand grip housing  3  that is embodied as an anti-vibration hand grip housing. 
     The hand grip housing  3  is supported on a tool housing  2  by means of a leaf spring  7 . In this case, the leaf spring  7  comprises a first end (not visible) and a second end  72 , wherein the leaf spring is fixedly connected by means of its first end to the tool housing  2 . At the second end  72  of the leaf spring  7 , the hand grip housing  3  is supported on the upper face  73  of said leaf spring, so that the hand grip housing  3  can move in a resilient manner in the horizontal and the vertical direction. As a consequence, it is possible for a relative movement of several millimeters to occur between the tool housing  2  and the hand grip housing  3 . A bellows element  21  is provided between the tool housing  2  and the hand grip housing  3 , so that this relative movement between the tool housing  2  and the hand grip housing  3  is possible without damaging the tool housing  2  or the hand grip housing  3 . 
     A recessed grip molding  31  can be releasably attached to the hand grip housing  3 , so that machine components that are arranged in the hand grip housing  3  can be accessed from outside. 
     The electric power tool  1  of this exemplary embodiment is a hammer drill that can be adjusted by means of an operating mode switch  41  into the operating modes: “drilling”, “hammer drilling” and “chipping”. Within the framework of  FIGS. 1-6 , the terms “electric power tool  1 ” and “hammer drill” are used synonymously. A slider  42  can be displaced by means of the operating mode switch  41  in a displacement direction  43  or in the opposite direction thereto, wherein the slider  42  is displaced against the force of a compression spring  44  that is supported on the tool housing  2 . 
     A first end  61  of a second actuating means  6  that is embodied in this case as a band is fixed on the slider  42 . Within the framework of  FIGS. 1-6 , the terms “second actuating means  6 ” and “band” are used synonymously. In the present exemplary embodiment, the first end  61  is retained on account of the prestressing of the spring  63 . However, embodiments are also preferred in which the band  6  is fixedly connected to the slider  42 , for example by means of a screw or clip connection. As an alternative, in this case it is also possible to provide a Bowden cable (not illustrated) in place of the band  6 . 
     A second end  62  of the band  6  is fixed to a hook  531  of a second signal means  53  of a second switching device  5  (cf.  FIGS. 3-6 ) of an electric switch  800 , so that the operating mode switch  41  is connected by way of the band  6  directly to the second signal means  53 . The second signal means  53  is in this case embodied as a switching lever. Within the framework of  FIGS. 1-6 , the terms “second signal means  53 ” and “switching lever” are used synonymously; and in fact, the second end  62  in this case is retained in the hook  531 . It is, however, also preferred that the second end  62  is fixedly connected to the second switching device  5 . 
     The operating mode switch  41  is therefore connected by way of the band  6  in a mechanical manner to the second switching device  5 . 
     A first actuating means  9  that is embodied in this case as a rocker switch is arranged on the electric switch  800 . Within the framework of  FIGS. 1-6 , the terms “first actuating means  9 ” and “rocker switch” are used synonymously. The rocker switch  9  is rotatably mounted on the switch housing of the electric switch  800 . Said rocker switch comprises a first rocker switch part  91  and a second rocker switch part  92 . A first switching device  8  of the electric switch  800  can be adjusted by means of actuating the first rocker switch part  91  from a first switching mode A into a second switching mode E. In the present exemplary embodiment, the electric switch  800  is embodied as an operating switch of the electric power tool  1 . Within the framework of  FIGS. 1-6 , the terms “electric switch  800 ” and “operating switch” are therefore used synonymously. 
     Since the electric switch  800  in this case is the operating switch of the electric power tool  1 , the first switching mode A in this case is provided as a switched-off mode in which the electric power tool  1  is switched off, wherein the second switching mode E is a switched-on mode E in which the electric power tool  1  is switched on. Within the framework of  FIGS. 1-6 , the terms “first switching mode A” and “switched-off mode” and also “second switching mode E” and “switched-on mode” are used synonymously. 
     As the operating mode switch  41  is adjusted from the “drilling operation” or from the “hammer drill operation” into the operating mode “chipping operation”, the slider  42  is displaced in the displacement direction  43  by means of a cam contour (not illustrated) of the operating mode switch  41 . As a consequence, the slider  42  pulls on the band  6 , so that the second switching device  5  is adjusted from a third switching mode G against a restoring force, which is represented in this case by an arrow  58 , by means of the switching lever  53  into a fourth switching mode AR. 
     An operating switch  800  of a hammer drill  1  cannot be locked in the “drilling operation” or “hammer drill operation”, consequently said hammer drill does not continue to rotate in an uncontrolled manner as the drill tilts, so that the operator of the hammer drill is protected. The operating switch  800  must therefore be embodied as a matter of necessity as a push button in the “drilling operation” or “hammer drill operation”. In contrast thereto, it is preferred in the “chipping operation” that the operating switch  800  can be locked. It is therefore preferred in this operating mode that the operating switch  800  functions as a rocker switch. 
     The operating switch  800  is therefore provided in this case in such a manner that the third switching mode G is an initial mode in which the operating switch  800  cannot be locked or is not locked and which switching mode is set if the hammer drill  1  is located in the “drilling operation” or the “hammer drill operation”. Furthermore, the operating switch  800  is provided in this case in such a manner that the fourth switching mode AR is a locked mode in which the operating switch  800  can be locked or is locked and which fourth switching mode is set if the hammer drill  1  is located in the “chipping operation”. Within the scope of  FIGS. 1-6 , the terms “third switching mode G” and “initial mode” and also “fourth switching mode AR” and “locked mode” are therefore used synonymously. 
     In the case of a depressed first rocker switch part  91 , the operating switch  800  is consequently locked in the locked mode, if the hammer drill  1  is switched on. The operating switch  800  can in fact then be adjusted by means of depressing the second rocker switch part  92  from the switched-on mode E into the switched-off mode A, wherein the hammer drill  1  is switched off. However, the operating switch  800  remains then in the locked mode AR so that it can still be locked. 
     As the operating mode switch  41  is returned from the operating mode “chipping operation” into the “drilling operation” or into the “hammer drill operation” the slider  42  is displaced with the aid of the compression spring  44  in the opposite direction to the displacement direction  43 . Since the band  6  is of fixed length, said band follows the sliding movement of the slider  42 , so that the hook  531  is returned to its previous position, wherein the second switching device  5  is returned to its previous position, so that the operating switch  800  is returned from the locked position AR into the initial position G. In this case, the second switching device  5  is returned by means of the restoring force  58  into the initial position G. 
     The operating switch  800  and the rocker switch  9  are accessible from the outside by means of releasing and removing the recessed grip molding  31 . 
       FIG. 2  illustrates a section of the electric power tool  1  shown in  FIG. 1  and in fact in (a) in a perspective view and in (b) in a lateral sectional view.  FIG. 2  illustrates that connections  82  for connecting a current circuit (not illustrated), in this case the motor current circuit, are provided on the operating switch  800 . The connections  82  are provided at least partially outside a switch housing  80  of the operating switch  800 . In addition, it is also evident in this case that the switching lever  53  and a first signal means  85  that is embodied in this case as an angled lever and cooperates with the rocker switch  9 , are likewise provided at least partially outside the housing  80 , so that they are accessible from the outside. The operating switch  800  is, however, moreover arranged inside the switch housing  80  and consequently protected from dust and moisture. In addition, the electric switch  800  of this embodiment can be used as a modular component in a multiplicity of different electric power tools  1 . And finally, it is easy to handle a component that is protected by means of a switch housing  80 . 
     Within the framework of  FIGS. 2-6 , the terms “first signal means  85 ” and “angled lever” are used synonymously. 
       FIG. 3  illustrates in  FIGS. 3 ( a )-( c )  the operating switch  800  of the hammer drill  1  shown in  FIG. 1  and the rocker switch  9 , wherein the first switching device  8  of the operating switch  800  is located in the switched-off mode A and the second switching device  5  is located in the initial mode G. 
     The first switching device  8  comprises in this case two electrical contacts  83  and electrical connections  82  for closing the motor current circuit. Furthermore, said first switching device comprises a first adjusting means  81  that cooperates with the angled lever  85 . 
     The angled lever  85  that is mounted on the switch housing  80  of the operating switch  800  can rotate about an angled lever axis  850  by means of actuating the rocker switch  9 . For this purpose, said angled lever comprises an end  851 , which faces a rocker switch  9 , and an end  852 , which faces the operating switch  800 . A fastening means  859  is provided on the end  851  of said angled lever that faces the rocker switch  9  and the rocker switch  9  can be attached to said fastening means in a rotatable manner. The fastening means  859  is embodied in this case as an elongated hole, wherein a counter-fastening means  99  is provided on the rocker switch  9 , which counter-fastening means is embodied in this case as a connecting pin that is arranged on the rocker switch  9 . Fundamentally, however, it is also possible to provide a different rotating or sliding connection. 
     The angled lever  85  is embodied in a similar manner to an arcuate extension on its end  852  that faces the operating switch  800 . The end  852  of the angled lever, which end is embodied in a similar manner to an arcuate extension and faces the operating switch  800 , is described within the framework of  FIGS. 3-6  as an arcuate extension. The arcuate extension  852  comprises an end  853  that faces the second switching device  5  and also comprises an end  854  that is remote from the second switching device  5 . The end  854  that is remote from the second switching device  5  lies against a contacting means  811  of the first adjusting means  81 . The first adjusting means  81  is embodied in this case as a sliding means. Within the framework of  FIGS. 3-6 , the terms “first adjusting means  81 ” and “sliding means” are used synonymously. The first adjusting means  81  can, however, also be embodied as a rotating means in place of a sliding means. 
     The sliding means  81  can be displaced against the force of a first force means (not illustrated). 
     The rocker switch  9  is rotated about a rocker switch axis  90  in an actuating direction  907  by means of actuating the first rocker switch part  91 . In this case, the angled lever  85  is rotated about the angled lever axis  850  in an angled lever direction  857 . As a consequence, the sliding means  81  is displaced in the sliding direction  84 , wherein the electrical contacts  83  are likewise displaced in the sliding direction  84 , until said electrical contacts lie against the electrical connections  82  and connect said electrical connections, so that the motor current circuit is closed. As a consequence, the operating switch  800  is adjusted from the switched-off position A into the switched-on position E. 
       FIG. 4  illustrates in  FIGS. 4 ( a )-( c )  the operating switch  800  shown in  FIG. 3 , wherein the first switching device  8  of the operating switch  800  is located in the switched-on mode E and the second switching device  5  is located in the initial mode G. 
     On account of the restoring force of the first force means, the sliding means  81  in the initial mode G is displaced in the opposite direction to the sliding direction  84  as the rocker switch  9  is released, wherein the electric contacts  83  are displaced in the opposite direction to the sliding direction  84 , so that said electrical contacts are displaced away from the electrical connections  82  and the motor current circuit is open. In this case, the part  854  of the angled lever  85  that is remote from the rocker switch  9  is displaced by means of the contacting means  811  of the sliding means  81  in the opposite direction to the sliding direction  84 , wherein the angled lever  85  is rotated in the opposite direction to the angled lever direction  857  and wherein the rocker switch  9  is rotated in the opposite direction to the actuating direction  907 . As a consequence, the operating switch  800  is returned from the switched-on position E to the switched-off position A. 
     It is evident from both  FIG. 3  and  FIG. 4 , that, by adjusting the first switching device  8  from the switched-off mode A into the switched-on mode E and the reverse, the angled lever  85  can be rotated freely about the angled lever axis of rotation  85 , if the second switching device  5  is located in the initial mode G. In the initial mode G, the operating switch  800  therefore cannot be locked or is locked either in the switched-on mode E or in the switched-off mode A. 
     In the embodiment illustrated in this case, the operating switch  800  therefore always functions in the initial mode G as a push button. 
       FIG. 5  illustrates in  FIGS. 5 ( a )-( c )  the operating switch  800  shown in  FIG. 3 , wherein the first switching device  8  of the operating switch  800  is located in the switched-off mode A and the second switching device  5  is located in the locked mode AR. 
     The second switching device  5  comprises a second adjusting means  54  that is embodied in this case as a locking latch and is mounted on the switching lever  53  in such a manner as to be able to rotate about a locking latch axis  540 . Within the framework of  FIGS. 3-6 , the terms “second adjusting means  54 ” and “locking latch” are used synonymously. 
     The switching lever  53  is mounted on the switch housing  80  of the operating switch  800  in such a manner as to be able to rotate about a switching lever axis  530 . As the operating mode is adjusted from the “drilling operation” or “hammer drill operation” into the “chipping operation”, the second switching device  5  is adjusted from the initial mode G into the locked mode AR, in that the switching lever  53  is rotated in a switching lever direction  537  about the switching lever axis  530  against the force  58  of the second force means that is embodied in this case as a compression spring. Since the locking latch  54  is mounted on the switching lever  53 , said locking latch co-rotates with the switching lever  53 . 
     A raising means  52  that is embodied in this case as a lug is arranged on the locking latch  54 . Within the framework of  FIGS. 3-6 , the terms “raising means  52 ” and “lug” are used synonymously. The lug  52  is arranged on the face of the locking latch  54  that faces the arcuate extension  852 . The locking latch  54  is pushed on its face remote from the arcuate extension  852  by means of a compression spring  55  against the switching lever  53 . 
     As the second switching device  5  is adjusted from the initial mode G into the locked mode AR, the locking latch  54  is co-rotated with the switching lever  53  until the lug  52  is arranged in the switched-off mode A of the first switching device  8  in the arcuate region of the arcuate extension  852 . 
     As the first switching device  8  is adjusted from the switched-off mode A into the switched-on mode E, the angled lever  85  is rotated about the angled lever axis  850  in the angled lever direction  857 , wherein the arcuate extension  852  is also rotated in the angled lever direction  857  and on account of its arcuate shape it slides along the lug  52 , without being hindered by said lug, until the locking latch  54  lies with an end surface  541  (cf.  FIGS. 4( b ), ( c ) ) that faces the first switching device  8  against a locking means  812  of the first switching device  8 . The compression spring  55  urges the end surface  541  of the locking latch  54  in this case against the locking means  812  of the switching slider  81 . In this locked mode AR, the switching slider  81  cannot be displaced by means of the force of the force means back in the opposite direction to the sliding direction  84 . 
       FIG. 6  illustrates in  FIGS. 6 ( a )-( c )  the operating switch  800  shown in  FIG. 3 , wherein the first switching device  8  of the operating switch  800  is located in the switched-on mode E and the second switching device  5  is located in the locked mode AR. 
     As the rocker switch  9  is released, the sliding means  81  is pushed or pulled in the opposite direction to the sliding direction  84  on account of the restoring force of the first force means. Since the contacting means  811  of the sliding means  81  lies against the end  854  of the arcuate extension  852  that is remote from the second switching device  5 , the angled lever  85  in this case can be pushed back. However, since the end surface  541  of the locking latch lies against the locking means  812  of the first switching device  8 , the sliding means  81  cannot be pushed back in the opposite direction to the sliding direction  84 . At the same time, the arcuate extension  852  of the angled lever  85  then lies with its end  853  that is facing the second switching device  5  on the lug  52 , so that said angled lever cannot be rotated back into the previous position. 
     In contrast thereto, by means of depressing the second rocker switch part  92 , the angled lever  85  is rotated about the angled lever axis  850  in the opposite direction to the angled lever direction  857  by means of sufficient force being applied by the operator. In this case, the end  853  of the arcuate extension  852  that faces the second switching device  5  raises the raising means  52  so that the locking latch  54  rotates about the locking latch axis  540  in a release direction and the end face  541  of the locking latch  54  is raised from the locking means  812 . In so doing, the compression spring  55  is initially compressed against its restoring force. The raising means  52  then slides along the arcuate extension  852  until said raising means is arranged in the switched-off mode A of the first switching device  8  back in the arcuate region of the arcuate extension  852 , wherein the stress in the compression spring  55  is at least partially relieved. 
     On account of the restoring force of the first force means, the sliding means  81  is displaced in the opposite direction to the sliding direction  84 , so that the motor current circuit is open. In this case, the part  854  of the angled lever  85  that is remote from the rocker switch  9  is displaced by means of the contacting means  811  of the sliding means  81  in the opposite direction to the sliding direction  84 , wherein the angled lever  85  is rotated in the opposite direction to the angled lever direction  857 . As a consequence, the operating switch  800  is returned from the switched-on position E into the switched-off position A. 
     The first switching device  8  of the operating switch  800  is then located back in the switched-off mode A, wherein the second switching device  5  is located in the locked mode AR (cf.  FIG. 5 ). 
     In the locked mode AR, the operating switch  800  can therefore be locked in the switched-off mode A, wherein said operating switch is adjusted into the switched-on mode E. In the switched-on mode E, however, said operating switch is, in contrast thereto, locked by means of the second switching device  5 . The operating switch  800  therefore functions in the locked mode AR as a rocker switch. 
     In addition, the operating switch  800  can be adjusted only in the locked mode AR by means of actuating the second rocker switch part  92  from the switched-on mode E into the switched-off mode A. In the initial mode G in which the operating switch  800  functions as a push button, the rocker switch  9  is, in contrast, automatically rotated back about the rocker switch axis  90  in the opposite direction to the actuating direction  907  as the first switching device  8  is returned to its previous position (cf.  FIG. 4 ). 
     As the operating switch is returned from the “chipping operation” into the “drilling operation” or “hammer drill operation”, the switching lever  53  is rotated about the switching lever axis  530  in the opposite direction to the switching lever direction  537  on account of the restoring force of the second force means  56 , wherein the band  6  is returned to its previous position. Since the switching latch  54  is mounted on the switching lever  53 , said switching latch co-rotates with the switching lever  53 . 
     In this case, the end face  541  of the locking latch  54  rotates about the locking latch axis  540 , wherein said end face rotates away from the locking means  812  of the sliding means  81  and in fact irrespectively of whether the first switching device  8  is located in the switched-on mode E or in the switched-off mode A. Based on the switched-off mode E, it is effected that by rotating the end face  541  away from the locking means  812  the sliding means  81  is displaced in the opposite direction to the sliding direction  84  on account of the restoring force of the first force means, wherein the angled lever  85  is rotated in the opposite direction to the angled lever direction  857 , wherein the rocker switch  9  is rotated in the opposite direction to the rocker switch direction  907  and wherein the first switching device  8  is adjusted into the switched-off mode A. The second switching device  5  is then located in the initial mode G.