Abstract:
Switch apparatus ( 1 ) for switching on and off a power tool, including a pushbutton element ( 10 ), which is pivotable reversibly about a pivot point (S) between a switch-on position and a switch-off position, wherein in the switch-on position the machine tool is switched on and in the switch-off position the machine tool is switched off; and a locking device ( 30 ) for releasably locking the pushbutton element ( 10 ) in the switch-on position. The locking device ( 30 ) includes a stop element ( 38 ) and the pushbutton element ( 10 ) includes a counter-stop element ( 40 ), wherein the stop element ( 38 ) is movable reversibly between a locking position, in which the stop element ( 38 ) bears against the counter-stop element ( 40 ) and the pushbutton element ( 10 ) is held in the switch-on position, and a release position, in which the pushbutton element ( 10 ) is returnable to the switch-off position.

Description:
[0001]    The present invention relates to a switching device for switching a power tool on and off, including a pusher element, which is reversibly pivotable about a pivot point between a switch-on position and a switch-off position, where the power tool is switched on in the switch-on position and the power tool is switched off in the switch-off position; and a locking mechanism for releasably locking the pusher element in the switch-on position. 
       BACKGROUND 
       [0002]    Such switching devices are widely known and are utilized primarily for electric power tools including an electric motor, such as, for example, drills, grinders, saws, planers, angle grinders, and the like. The power tool may be a battery-operated and/or mains-operated power tool. 
         [0003]    An electric switch including a housing for a power tool is known from DE 24 10 871 A1. A contact system is located in the housing. An actuating element situated on the housing is movable between a starting position and an end position. In the end position, the actuating element acts upon the contact system in a switching manner. The switch may be provided with a switch-on lock for the actuating element in the starting position and/or with a catch for the actuating element in the end position. The switch-on lock and/or the catch include/includes an actuating element and each also includes a blocking element, which interacts with the actuating element and may be situated on the housing. 
         [0004]    In addition, an electric switch is also shown from EP 2 101 340 A1, which is suitable for use in a hand-held power tool including an electric motor. For this purpose, the switch includes a housing in which a contact system is located. An actuating element for acting on the contact system in a switching manner, which is movable between a starting position and an end position, is situated on the housing. The switch may optionally be provided with a switch-on lock and/or a catch for the actuating element, the switch-on lock and/or the catch including an actuating element and a blocking element interacting with the actuating element. The blocking element is situated on the housing in such a way that, when the actuating element moves into the end position, the blocking element plunges into a recess in the actuating element. In addition, the blocking element is designed in such a way that an optional interaction with the actuating element for either the switch-on lock and/or for the catch is made possible. 
         [0005]    The above-described switching devices from the prior art are often designed to be highly complex and bulky, so that, due to spatial limitations, either only a locking mechanism, which holds the switching element in a switch-on mode, or only a transport safety device, which blocks the switching element when the power tool is transported, may be implemented in the particular switching device. A switching device into which both a locking mechanism and a transport safety device may be integrated is therefore possible only if the entire switching device is substantially enlarged. 
         [0006]    In addition, the switching devices from the prior art also frequently have the problem that the locking mechanism may come loose in the presence of strong vibrations of the type that may occur during the use of the power tool, and the power tool unintentionally switches off again. 
       SUMMARY OF THE INVENTION 
       [0007]    It is an object of the present invention to provide an improved switching device for switching a power tool on and off, which eliminates the above-described problems and, in particular, includes a space-saving and vibration-resistant locking mechanism. 
         [0008]    The present invention provides a switching device for switching a power tool on and off, including a pusher element, which is reversibly pivotable about a pivot point between a switch-on position and a switch-off position, where the power tool is switched on in the switch-on position and the power tool is switched off in the switch-off position; and a locking mechanism for releasably locking the pusher element in the switch-on position. 
         [0009]    According to the present invention, it is provided that the locking mechanism includes a stop element and the pusher element includes a counter-stop element, where the stop element is reversibly movable between a locking position, in which the stop element rests against the counter-stop element and the pusher element is held in the switch-on position, and a release position, in which the pusher element is returnable to the switch-off position. As a result, a space-saving locking mechanism is achieved, due to which sufficient space for a transport safety device remains in the switching device. 
         [0010]    According to a further advantageous embodiment of the present invention, it may be provided that the stop element has a chamfered stop surface and the counter-stop element has a counter-stop surface corresponding to the chamfered stop surface. Due to the stop surface and the counter-stop surface corresponding thereto, a release of the locking mechanism caused by high vibrations during the use of the power tool may be effectively prevented. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The present invention is described in greater detail with respect to advantageous exemplary embodiments. 
           [0012]      FIG. 1  shows a side view of a power tool including a measuring device according to the present invention for measuring an operating time of a power tool; and 
           [0013]      FIG. 2  shows a diagram of the measuring device according to the present invention, 
           [0014]      FIG. 3  shows a diagram of the measuring device according to the present invention, 
           [0015]      FIG. 4  shows a diagram of the measuring device according to the present invention; and 
           [0016]      FIG. 5  shows a diagram of the measuring device according to the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]      FIGS. 1 through 5  show a switching device  1  according to the present invention for switching a power tool on and off. The power tool is, for example, a drill, a percussion drill, a grinder, a saw, a planer, an angle grinder, or the like, including an electric motor. 
         [0018]    Switching device  1  essentially includes a pusher element  10 , a switch housing  20 , and a locking mechanism  30 . 
         [0019]    Pusher element  10 , in turn, includes an L-shaped switching element  11 , a compression spring  15 , and an unlocking switch  16 . L-shaped switching element  11  is formed from a first (short) portion  12  and a second (long) portion  14 . 
         [0020]    First portion  12  includes a first end  12   a,  a second end  12   b,  a first surface  12   c,  and a second surface  12   d.  Second portion  14  likewise includes a first end  14   a,  a second end  14   b,  a first surface  14   c,  and a second surface  14   d.  First surface  14   c  of second portion  14  is utilized, in particular, as the bearing surface for the fingers (not shown) of a user who intends to press pusher element  10  in order to switch on the power tool. Second surface  14   d  of second portion  14  includes a contact element (not shown), with the aid of which a counter-contact element  13  on switch housing  20  may be actuated when pusher element  10  is pivoted relative to switch housing  20 . Second end  12   b  of first portion  12  is fixedly connected to first end  14   a  of second portion  14 . Second end  14   b  of second portion  14  has a pivot point S on pivot axis R, about which switching element  11  may be pivoted (see also  FIG. 5 ). Switching element  11  is pivotably connected to switch housing  20  via pivot point S. The pivoting about pivot point S is utilized for reversibly moving switching element  11  between a switch-off position and a switch-on position and relative to switch housing  20  and also relative to locking mechanism  30 . 
         [0021]    As represented in  FIG. 3 , compression spring  15  is positioned on first portion  12  of switching element  11  and is therefore located between switching element  11  and switch housing  20 . Compression spring  15  is utilized for automatically returning pusher element  10  or switching element  11  from the switch-on position into the switch-off position. 
         [0022]    Unlocking switch  16  is utilized as a transport safety device and ensures that pusher element  10  cannot be pivoted and the power tool cannot be started when this transport safety device is not pressed. Unlocking switch  16  is located, pivotably mounted, on first surface  14   c  of second portion  14  between first portion  12  and second portion  14  of switching element  11 .  FIG. 1  shows unlocking switch  16  in a first position G (dashed line), in which unlocking switch  16  is not actuated and pusher element  10  is blocked, and in a second position E (solid line), in which unlocking switch  16  is actuated and pusher element  10  is no longer blocked. 
         [0023]    Locking mechanism  30  essentially includes a cylindrical base body  32 , an actuating switch  36 , a stop element  38 , and a counter-stop element  40 . 
         [0024]    As shown in  FIG. 3 , cylindrical base body  32  has a first end  32   a,  a second end  32   b,  and a cylindrical hollow space  33 . Actuating switch  36  is positioned on first end  32   a  of cylindrical base body  32 . A compression coil spring  37  is located in hollow space  33 . 
         [0025]    Stop element  38  includes an elongate base body  39  having a first end  39   a  and a second end  39   b.  Stop element  38  is positioned via first end  39   a  of elongate base body  39  at the lateral surface of cylindrical base body  32  in such a way that this stop element  38  extends at a right angle (extending in direction P) with respect to cylindrical base body  32 . A stop surface  39   c  which is chamfered, i.e., rising in direction N, is located on second (free) end  39   b  of elongate base body  39 . 
         [0026]    Cylindrical base body  32 , actuating switch  36 , and stop element  38  are attached on a housing (not shown) of the power tool (also not shown). Pusher element  10  may therefore be pivoted relative to cylindrical base body  32 , actuating switch  36 , and, in particular, relative to stop element  38 . 
         [0027]    In addition, cylindrical base body  32 , actuating switch  36 , and stop element  38  may be reversibly moved between a locking position (as shown in  FIG. 4 ) and a release position (as shown in  FIGS. 1, 2, 3 ). Compression coil spring  37  is utilized for allowing cylindrical base body  32 , actuating switch  36 , and stop element  38  to be automatically returned from the locking position into the release position without actuation of actuating switch  36 . As described in greater detail in the following, the locking position is utilized for holding pusher element  10  in the switch-on position. In the release position of locking mechanism  30 , pusher element  10  may be returned to the switch-off position (see also  FIGS. 1 and 2 ). 
         [0028]    Counter-stop element  40  essentially includes a right-angled base body  42  having a top side  42   a  and an underside (not shown). A cylindrical pin  44  having a chamfered counter-stop surface  44   a  is positioned on top side  42   a.  Counter-stop surface  44   a  extends downward in direction N and therefore corresponds to stop surface  39   c  of stop element  38 . Counter-stop element  40  is positioned on top side  12   c  of first portion  12  of L-shaped switching element  11 , whereby counter-stop element  40  may be moved relative to cylindrical base body  32 , actuating switch  36 , and stop element  38  (as a result of the pivot motion of pusher element  10  in direction Q) 
         [0029]    By pressing unlocking switch  16 , the blockade of pusher element  10  is released and pusher element  10  may be pivoted about pivot axis R in direction Q. 
         [0030]    As a result of the pivoting of pusher element  10 , switching element  11  is also moved, so that this switching element is moved in direction P from the switch-off position into the switch-on position and, therefore, relative to switch housing  20 . Since counter-stop element  40  is fixedly connected to first portion  12  of switching element  11 , this counter-stop element is likewise moved with pusher element  10  into the switch-on position and, therefore, in direction P (see also  FIG. 3 ). As a result, the contact element (not shown) positioned on second surface  14   d  of second portion  14  of switching element  11  is pressed against counter-contact element  13  on switch housing  20 , whereby the power tool is switched on. In this case, the power tool remains switched on for as long as the contact element is pressed against counter-contact element  13 . When pressure is no longer applied onto pusher element  10 , this pusher element pivots from the switch-on position back into the switch-off position and, therefore, the power tool is switched off. 
         [0031]    Pusher element  10  may be held in the switch-on position with the aid of locking mechanism  30  without the need for the user to continue applying pressure onto pusher element  10 . 
         [0032]    For this purpose, pressure is applied onto actuating switch  36 , so that this actuating switch is moved in direction N and against compression coil spring  37 . Cylindrical base body  32 , actuating switch  36 , and stop element  38  move in direction N into the locking position. In order to finally hold pusher element  10  in the switch-on position, counter-stop surface  44   a  of counter-stop element  40  and stop surface  39   c  of stop element  38  are pressed against one another, against the pressure of compression spring  15 . Given that compression spring  15  is substantially stronger than compression coil spring  37  and, in particular, due to chamfered stop surface  39   c  and counter-stop surface  44   a  corresponding thereto, stop surface  39   c  and counter-stop surface  44   a  remain in contact with one another (see also  FIG. 4 ). Consequently, due to locking mechanism  30 , pusher element  10  remains in the switch-on position and the power tool therefore remains switched on despite strong vibrations. 
         [0033]    In order to release the locking, i.e., the fixed setting of pusher element  10 , again and therefore enable pusher element  10  to move from the (blocked) switch-on position back into the switch-off position, pressure is initially applied onto switching element  11  in order to move pusher element  10  in direction P. Due to this movement in direction P, stop surface  39   c  and counter-stop surface  44   a  corresponding thereto are moved apart from one another again, so that a certain gap forms between the two surfaces  39   c,    44   a.  As soon as the gap forms between the two surfaces  39   c,    44   a,  cylindrical base body  32 , actuating switch  36 , stop element  38  move under the pressure of compression coil spring  37  in cylindrical base body  32  from the locking position (as shown in  FIG. 4 ) into the release position (as shown in  FIGS. 1, 2, 3 ). For this purpose, elongate base body  39  is moved against direction N so far that counter-stop element  40  may move laterally past elongate base body  39  (see also  FIGS. 1 and 2 ). Therefore, pusher element  10  may be pivoted back from the switch-on position into the switch-off position and the contact element no longer presses against counter-contact element  13 , whereby the power tool is switched off.