SWITCH FOR A HAND-HELD POWER TOOL

Abstract

A switch (30) for a hand-held power tool (10) or as a component of a hand-held power tool (10), which has an electric drive motor (16) that can be switched by the switch (30). The switch (30) has a switch housing (33) with a switch chamber (35) in which a switch actuator (75) that can be moved between at least two switch positions (ML, MR) is arranged in order to actuate an electric switch element, said switch actuator being kinetically coupled, by means of a transmission element (70), to a switch (30) actuation element (32), which is arranged outside the switch housing (33) and can be moved between at least two actuation positions (R, L), wherein the transmission element (70) passes through a through-opening (54) on a wall of the switch housing (33) such that the switch actuator (75) can be moved by moving the actuation element (32) in order to actuate the switch element (24). A rotary bearing (77) is arranged in the through-opening (54), the transmission element (70) being rotatably mounted on the rotary bearing about a rotational axis (D).

Claims

1. A switch for a hand-held power tool or as a component of a hand-held power tool, which has an electric drive motor that can be switched on by the switch, wherein the switch has a switch housing with a switch chamber in which a switch actuator that can be moved between at least two switch positions is arranged in order to actuate an electric switch element and is movement-coupled with the aid of a transmission element to an actuating element of the switch, located outside the switch housing and movable between at least two actuating positions, wherein the transmission element passes through a through opening in a wall of the switch housing, so that the switch actuator may be moved by moving the actuating element to actuate the switch element and wherein, at the through opening, there is provided a rotary bearing, on which the transmission element is rotatably mounted around a rotation axis.

2. The switch according to claim 1, wherein the rotation axis passes through the wall on which the rotary bearing is provided.

3. The switch according to claim 1, wherein the rotation axis is at an angle, to a wall face of the wall on which the rotary bearing is arranged or runs.

4. The switch according to claim 1, wherein the switch chamber is closed with the exception of the through opening.

5. The switch according to claim 1 wherein, at the through opening shift-lock contours and/or a shift-lock are provided for a non-displaceable hold of the actuating element parallel to the rotation axis or along the rotation axis.

6. The switch according to claim 1, wherein at one of the through opening and transmission element, there is provided at least one partly annular or completely annular flange, which engages in a partly annular or completely annular slot of the other component of through opening and transmission element.

7. The switch according to claim 1, wherein there is provided at the through opening and/or the rotary bearing a seal, or wherein the through opening and/or the rotary bearing are in the form of a seal or have a seal.

8. The switch according to claim 7, wherein the seal encompasses the transmission element annularly.

9. The switch according to claim 7, wherein the seal comprises a seal flange which engages in an annular seal location.

10. The switch according to claim 7 wherein the seal comprises a labyrinth seal.

11. The switch according to claim 1, wherein the actuating element is translationally mounted on a slide bearing relative to the switch housing.

12. The switch according to claim 1, wherein a transmission gear is provided between the switch actuator and the actuating element.

13. The switch according to claim 12, wherein the transmission gear located outside the switch housing.

14. The switch according to claim 12, wherein the transmission gear is designed and provided to convert a linear movement or translational movement of the actuating element into a rotational movement of the switch actuator.

15. The switch according to claim 12, wherein the transmission gear comprises or is formed by a crank gear and/or a toothed gearing.

16. The switch according to claim 1, wherein the transmission element is rotatably mounted, with longitudinal clearance relative to the rotation axis to the rotary bearing which is located on the wall of the switch housing, to the switch housing.

17. The switch according to claim 1, wherein the actuating element forms a first actuating element and the switch actuator forms a first switch actuator to actuate the electrical switch element forming a first switch element and wherein the switch has a second actuating element, located outside the switch housing and adjustable between at least two actuating positions, and a second switch actuator, actuable by the second actuating element to actuate a second electrical switch element, wherein the second actuating element is movement-coupled to the second switch actuator with the aid of a second transmission element, which penetrates a second through opening in a wall of the switch housing.

18. The switch according to claim 17, wherein the second transmission element is mounted with linear movement facility along a sliding axis with respect to the switch housing and/or the second transmission element penetrates the second through opening with linear movement along a sliding axis.

19. The switch according to claim 18, wherein the sliding axis is parallel to the rotation axis or runs at an angle of less than 90° to the rotation axis.

20. The switch according to claim 17 wherein the actuating elements are arranged on the same side of the switch housing and/or the first through opening and the second through opening are arranged on side walls flush with one another or a common side wall and/or the same flat side of the switch housing.

21. The switch according to claim 17, wherein a drive section of the transmission gear in engagement with the first actuating element is located in a space between the switch housing and the second actuating element or protrudes into that space.

22. The switch according to claim 17, wherein at least one of the actuating elements has blocking contours for blocking the other actuating element, wherein an or the actuating element in a predetermined actuating position, blocks an actuation of the other actuating element from a first actuating position into a second actuating position.

23. The switch according to claim 22, wherein the actuating elements are designed for reciprocal blocking.

24. The switch according to claim 22 wherein the blocking contours are not in direct contact with and/or disengaged from the transmission element and/or a transmission gear between the transmission element and the actuating element which actuates it.

25. The switch according to claim 17, wherein the switch chamber accommodating the first switch actuator forms a first switch chamber and the second switch actuator is located in a second switch chamber separate from this first switch chamber.

26. The switch according to claim 25, wherein the first and the second switch chamber are separated or screened off from one another by a partition wall.

27. The switch according to claim 25, wherein the first switch chamber is sealed off from the second switch chamber.

28. The switch according to claim 17, wherein the second switch chamber is closed except for the second through opening.

29. The switch according to claim 17, wherein a seal is provided at the second through opening.

30. The switch according to claim 17, wherein the first switch actuator and the first switch element are provided and designed for presetting a direction of rotation of the drive motor of the hand-operated power tool and/or the second switch actuator and the second switch element for switching on and off and/or for changing a speed of the drive motor of the hand-operated power tool.

31. The switch according to claim 1, further comprising a spring assembly for biasing at least one switch actuator into a predetermined switching position and/or a latching arrangement for engaging at least one switch actuator in a predetermined switching position.

32. The switch according to claim 1, further comprising at least one switch actuator, which is in the form of a non-contact switch actuator and/or a magnet or includes a magnet sensor.

33. The switch according to claim 1, wherein at least one of the electrical switch elements is located outside the switch housing and/or on a printed circuit board.

34. The switch according to claim 1, wherein at least one electrical switch element which may be operated by the switch is provided on a printed circuit board, with the relevant electrical switch element arranged in sandwich form between the switch housing and the printed circuit board and/or the printed circuit board is cast with the switch housing with the aid of a casting compound.

35. The switch according to claim 1, further comprising at least one switch actuator and at least one electrical switch element actuable by the switch actuator which, on first actuation by the switch actuator may be actuated from a sleep mode into an active mode, wherein the switch element and an electrical device of the hand-operated power tool, actuable by the switch element and connected electrically to it, in the sleep mode uses no electrical energy or less electrical energy than in the active mode.

36. The switch according to claim 1, wherein the switch housing has a housing base part and a housing cover for closing the housing base part, wherein in each case one segment of at least one through opening is provided for a transmission element on the housing base part and on the housing cover, so that the housing base part and the housing cover form the through opening in a complementary manner and encompass the transmission element when they are fitted together.

37. The switch according to claim 36, wherein between the housing top part and the housing base part, there is provided at least one seal and/or wherein the housing base part and the housing cover are locked together with the aid of a latching arrangement.

38. A hand-operated power tool with a switch according to claim 1.

Description

[0055] An embodiment of the invention is explained below with the aid of the drawing, which shows in:

[0056] FIG. 1 a side view of a hand-operated power tool with a switch and with its machine casing open

[0057] FIG. 2 a top view of a power supply unit and the switch of the hand-operated power tool according to FIG. 1

[0058] FIG. 3 a side view of the switch according to the above Figures with switch housing open and unactuated second actuating element or switch-on element

[0059] FIG. 4 the view according to FIG. 3, but with the first actuating element in switch-on position

[0060] FIG. 5 a perspective oblique view of the switch element according to the above Figures, with the second actuating element in a neutral actuating position

[0061] FIG. 6 the view according to FIG. 5, but with an actuating element moved into a first actuating position assigned to an anti-clockwise rotation of the drive motor of the hand-operated power tool according to FIG. 1

[0062] FIG. 7 the view according to FIG. 5 or 6, but with the second actuating element moved into a second actuating position assigned to a clockwise rotation of the drive motor

[0063] FIG. 8 a section through the switch element according to the above Figures, along a section line A-A in FIG. 3 corresponding to the actuating position according to FIG. 5

[0064] FIG. 9 the section according to FIG. 8, but in the actuating position according to FIG. 6 of the first actuating element

[0065] FIG. 10 the section according to FIGS. 8, 9, but with the first actuating element moved into the actuating position according to FIG. 7

[0066] FIG. 11 an exploded view of the switch according to the above Figures and

[0067] FIG. 12 a perspective oblique view of the switch according to the above Figures, at an angle from above.

[0068] A hand-operated power tool 10 has a machine casing 11, in which is provided a drive train 15 with a drive motor 16. The drive train 15 is located in a drive section 12, from which there extends a handle section 13 for gripping or grasping by an operator. The handle section 13 extends at an angle from the drive section 12 in the manner of a pistol grip, in particular at an angle of around 80-90°.

[0069] The drive motor 16 could drive directly an output element 19 with a suitable tool holder, in which is held for example a screwdriver, a drill or the like. Here, however, a gear 17 is connected between the drive motor 16 and the output element 19.

[0070] Provided to control and operate the drive train 15, and therefore the hand-operated power tool 10 as a whole, is a control module 20, which includes a power supply unit 21. The control module 20 is located substantially in the handle section 13. Regarding the machine casing 11 it should also be noted that only the rear other casing part 14 is shown in the drawing, while a complementary casing part, closing the interior of the machine casing 11 together with the shown casing part 14, is not visible in the drawing.

[0071] The power supply unit 21 includes a board 22, on which are located various electronic and electrical components for control of the drive motor 16, in particular for its power supply, and not visible in the drawing. Shown schematically, though, are switch elements 23 and 24, for example magnetic sensors. With switch element 23, for example, the power supply unit 21 and therefore the drive motor 16 may be switched on or off. The speed of the drive motor 16 may also be preset by switch element 23. One may also describe switch element 23 as host switch element. With switch element 24, a direction of rotation of the drive motor 16 may be set, for example clockwise or anti-clockwise rotation.

[0072] The power supply unit 21 is or may be connected with the aid of lines 25 to the drive motor 16, in particular to its energy coils of an energy coil assembly not shown in detail in the drawing. The drive motor 16 is for example a brushless motor or an electrically commutated motor. But also the use of a switch 30, for switching the switch elements 23 and switch element 24, would be readily possible with a universal motor or other electrical motor.

[0073] The power supply unit 21 is or may be connected with the aid of lines 26 to a supply interface 28, via which the hand-operated power tool 10 may be supplied with electrical power. For example, in a manner not shown, an electrical supply cable, e.g. a power cable, may be provided at the supply interface 28 for connection to an electrical supply network, for example with 110 volt or 230 volt a.c. Here however the hand-operated power tool 10 is a hand-operated power tool which may be operated cordlessly. The supply interface 28 serves for the connection of a schematically indicated electrical energy store 29, for example in to form of a battery pack. Energy stored in the energy store 29 is used to supply the power supply unit 21 and thus the drive motor 16.

[0074] When operating the hand-operated power tool 10 in especially dust-laden environments, there is however the risk that the sensitive electrical components, switch elements or the like will be contaminated. Especially problematic are ferromagnetic dusts, which can adhere magnetically to magnetic sensors, for example magnetic pick-ups of the switch according to EP 2 395 527 A1. These problems however do not occur with the switch 30, or only to a much reduced extent.

[0075] The switch 30 include actuating elements 31 and 32, by which the switch elements 23 and 24 may be actuated. Correspondingly, therefore, the actuating element 31 may be used to switch on and off the drive motor 16 and to influence its speed, while the actuating element 32 is provided for presetting the direction of rotation of the drive motor 16.

[0076] The switch 30 has a switch housing 33 in which switch chambers 34 and 35, separate from one another, are provided. The switch housing 33 includes a housing base part 36, which is closed by a housing cover 37. Both switch chambers 34 and 35 are closed on the peripheral side, with the exception of through openings 53, 54, at side walls 51, 52 of the switch chambers 34 and 35. Between the switch chambers 34 and 35 there is also a partition wall 42, which separates the switch chambers 34 and 35 from one another.

[0077] The housing base part 36 and the housing cover 37 form housing parts 36A, 37A, complementary to one another and closing the switch chambers 34, 35.

[0078] The housing base part 36 has a base 45 from which the peripheral walls 46 extend. The housing cover 37 has a ceiling 47 from which the peripheral walls 48 extend. The end faces of the peripheral walls 46, 48 together with the wall sections of the housing base part 36 and the housing cover 37 lie with their end faces opposite one another.

[0079] Provided at these end faces of the peripheral walls 46, 48, together with the partition wall sections of the partition wall 42, are sealing projections 38, 39 for bounding the switch chambers 34, 35, together with complementary seal locations 40, 41 in which the sealing projections 38, 39 engage with sealing and thereby form the seals 38A, 39A. The seals 38A, 39A seal the switch chambers 34, 35 from one another and from the environment. The sealing projections 38, 39 are for example in the form of springs, which engage in the seal locations 40, 41 which are in the form of locating slots.

[0080] The sealing projections 38, 39 form together with the seal locations 40, 41 for example labyrinth seals. Instead of the sealing projections 38, 39 it would also readily be possible to provide seal locations into which for example a rubber seal, in particular in the form of an O-ring or a seal lip, is inserted. The sealing projections 38, 39 could also be in the form of elastic sealing projections or rubber sealing projections.

[0081] In particular it is advantageous that the switch chambers 34 and 35 are sealed from one another and/or tightly separated from one another by the seals 38A, 39A. For example the seals 38A, 39A comprise a seal section 38B, for example in the form of a labyrinth seal, which extends along an area 35A, where the switch chambers 34 and 35 directly adjoin one another. For example the seal section 38B includes sections of the sealing projections 38, 39 and seal locations 40, 41 which engage in one another in the form of labyrinth seals.

[0082] Thus the two switch chambers 34, 35 are sealed by a seal assembly on the one hand from the environment, but on the other hand also relative to one another. Switch actuators 65, 75 accommodated in the interiors of the switch chambers 34, 35 are therefore protected from environmental influences.

[0083] The housing base part 36 and the housing cover 37 are latched together with the aid of a latching arrangement. Provided for example on the housing base part 36 are latching projections 43, in particular latching hooks or the like, which engage in latching locations 44 of the housing cover 37. The latching projections 43 and latching locations 44 form a latching arrangement 43A and are provided for example in the area of the peripheral walls 46, 48. Preferably several latching projections and latching locations are provided, spaced apart from one another, so that the housing cover 37 is held securely to the housing base part 36. Naturally, bonding, welding or other similar means of joining housing base part 36 and housing cover 37 would also be possible, so that these two parts are held firmly together and the switch chambers 34, 35 are sealed.

[0084] Provided advantageously on the switch housing 33, for example the housing cover 37, are line holders 49 which are suitable for holding lines, in particular the lines 25.

[0085] The switch housing 33 is also supported on the circuit board 22 with the aid of support feet 50. Through the support feet 50, a space is provided between the base 45 and the printed circuit board 22, in which the switch elements 23, 24, for example semiconductor elements, are arranged in sandwich fashion. It is possible that the base 45 is in contact with the switch elements 23, 24, for example lying flat against their upper side facing the switch 30. It is however also possible that there is a space between the base 45 and the switch elements 23, 24. From the base 45, a seal projection 51A extends preferably towards the printed circuit board 22 and bounds an interior in which the switch element 23 and/or the switch elements 24 are located. The switch housing 33 is namely advantageously cast with the printed circuit board 22 with the aid of a casting compound 27A, which is kept away from the seal projection 51A, so that the switch elements 23, 24 do not come into contact with the casting compound 27A, but are held as it were in a cavity sealed by the casting compound 27A, the base 45 and the printed circuit board 22. The casting compound 27A forms a cast body 27 which holds the switch housing 33 to the printed circuit board 22 and preferably protects electrical components mounted on the printed circuit board 22 from environmental influences.

[0086] The actuating element 31 is connected to the switch actuator 65 with the aid of a transmission body 60. The switch actuator 65 includes for example a magnet or is formed by a magnet 65A, through the effect of which the switch element 23 may be actuated. The transmission body 60 forms part of a sliding guide or a slide bearing 60A. The transmission body 60 has a shaft section 61 which is connected by a holding section 62, for example a holding projection, to the actuating element 31, for example engaging in a holding location 31A, in particular a plug-in socket of the same. The transmission body 60 therefore protrudes from the actuating element 31 towards the switch housing 33, in which it engages.

[0087] Located at the longitudinal end of the shaft section 61 opposite the actuating element 31 is a slide 63, which has linear guidance in a slide guide 57 with respect to the sliding axis S. The slide guide 57 is provided in the switch chamber 34, so that the slide 63 is held in the switch chamber 34 movable relative to the sliding axis S or along the sliding axis S. The slide guide 57 comprises e.g. a guide projection 57A and a guide socket 57B on the slide 63 and the switch chamber 34.

[0088] The sliding axis S and the rotation axis D are parallel to one another.

[0089] The switch actuator 65, for example a magnet, is located on the slide 63. By shifting the slide 63 and thus the switch actuator 65 along the sliding axis S, a relative position of the switch actuator 65 relative to the switch element 22 may be set, so that the latter adopts different switching positions. If then for example, starting from an actuating position A, which corresponds to a switch-off position, the actuating element 31 is actuated in the direction of an actuating position E, i.e. a switch-on position (FIG. 4), then the magnetic field of switch actuator 65 actuates switch element 23, for example to switch the drive motor 16 on or off or to vary its speed.

[0090] An advantageous measure provides that, on first actuation of the actuating element 31 from the actuating position A towards the actuating position E, switch element 23 is as it were awoken and the other components of the power supply unit 21 are activated. If the switch element 31 remains unactuated for a predetermined time, i.e. adopts actuating position A, then switch element 23 switches the hand-operated power tool 10 and its electronic components off, in particular the power supply unit 21, going therefore into a kind of sleep mode, so that electrical power consumption is minimal or even switched off.

[0091] The switch actuator 65 is biased, through a spring assembly 64A, by a spring 64 which is supported on a side opposite the through opening 53, namely on a support 58, in the direction of actuating position A. Consequently, therefore, the operator may, with the aid of an operating force BK, actuate the switch actuator 65 against the spring force of the spring 64, from actuating position A towards actuating position E.

[0092] Preferably provided at the through opening 53, which at the same time represents a bearing location of a slide bearing for the transmission body 60, is a seal 66. The seal 66, for example a seal ring, in particular a seal ring of plastic and/or an O-ring, is penetrated by the transmission body 60 and fits with sealing on its outer periphery. Provided in the switch housing 33, in particular the side wall 51 close to the through opening 53, is a seal location 55, for example an annular slot, for the seal 66. The housing base part 36 and the housing cover 37 have, in the area of the side wall 51, segments 67A, 67B of a bearing location 67 or the through opening 53. At the bearing location 67 or the through opening 53, the transmission body 60 has linear guidance with respect to the sliding axis S. The bearing location 67 comprises for example sleeve-like segments 67A, 67B fitted to the housing base part 36 and the housing cover 37.

[0093] Provided for actuation of the switch actuator 75 is a transmission element 70 which, in respect of the switch housing 33, is rotatably mounted around a rotation axis D. The transmission element 70 has a shaft section 71 which is substantially located within the switch chamber 35 and penetrates a through opening 54 on the side wall 52 of the switch chamber 35 or on the switch housing 33. The through opening 54 forms at the same time a bearing location of a rotary bearing 77 on the side wall 52. Provided on the housing base part 36 and on the housing cover 37 are sleeve-like segments 79A, 79B of the bearing location 79 or the through opening 54.

[0094] On a side opposite the side wall 52, the shaft section 71 is rotatably mounted at a bearing location 59 of a rotary bearing 59A. For example, to form the bearing location 59, support sections or wall sections 59B protrude from a wall section of the peripheral walls 46 and/or a wall section of the peripheral walls 48.

[0095] Between the bearing location 59 and the rotary bearing 77, the switch actuator 75, for example a magnet 75A, is mounted on the shaft section 71, e.g. of a location 73, by which the switch element 24 may be actuated. Depending on a particular rotary position or angular position of the switch actuator 75 relative to the rotation axis D, the switch actuator 75 moves between switching positions assigned to opposite directions of rotation of the drive motor 16, for example, clockwise and anti-clockwise rotation. At the same time the actuating element 32 which is for example in the form of a slide element, adopts actuating positions R and L.

[0096] Actuating element 32 is mounted along a positioning axis BS on the machine casing 11. The machine casing 11 has for example a bearing location 95, at which the actuating element 32 is mounted movably relative to the positioning axis BS. In actuating position R, for example a actuating section 96 of the actuating element 32 protrudes further from a side of the machine casing 11 than an actuating section 97 of the actuating element 32 from the other opposite side of the machine casing 11. The operator therefore presses on one of the actuating sections 96 or 97, in order to actuate the actuating element 32 from the actuating position R into the actuating position L or vice-versa.

[0097] To transfer the linear movement of the actuating element 32 along the positioning axis BS into a rotary movement of the transmission element 70 around the rotation axis D, a transmission gear 80 is provided. The transmission gear 80 is for example a crank gear 81. For example, there extends at an angle, in particular at a right-angle, from the shaft section 71 of the transmission element 70, a crank arm 72. From the crank arm 72 in turn extends an actuating arm 74, with the actuating arm 74, the crank arm 72 and the shaft section 71 being stepped when viewed from the side. Thus, a longitudinal axis of the shaft section 71 (corresponding to the rotation axis D) and a longitudinal axis of the actuating arm 74 are parallel to one another.

[0098] The crank arm 72 is rotatable around the rotation axis D and swivels in a circular path around the rotation axis D. The crank arm 72 is held pivotably, around a swivel axis K, between driving projections 82 which protrude from the actuating element 32. Provided between the driving projections 82, therefore, is a rotary bearing or swivel bearing 83 with the rotation axis or swivel axis K for the actuating arm 74. Thus the components of the transmission element 70 and the rotary bearing 82 located outside the switch housing 33 form the crank gear 81.

[0099] Shown schematically in the drawing but readily possible, is for example also that instead of the crank arm 72, a gear 172 is provided on the shaft section 71 and engages with a tooth section 182 of the actuating element 32, which is for example located on the side of the actuating element 32 facing this gear 172 and extends between its actuating sections 96, 97.

[0100] The crank gear 81 and therefore the transmission gear 80 are located outside the switch housing 33. The switch actuator 75, for example a magnet, on the other hand is located inside the switch housing 33, namely the switch chamber 35.

[0101] The actuating arm 74 forms a drive section 74A of the transmission gear 80 and at the same time of the transmission element 70. The shaft section 71 forms an output section 71A of the transmission gear 80 and at the same time of the transmission element 70. The transmission element 70 therefore has the drive section 74A and the output section 71A as integral parts.

[0102] Provided on the rotary bearing 77 is a seal 76, so that the transition zone between the transmission element 70 and the switch chamber 35 is sealed. The seal 76 comprises for example a seal flange 78, for example designed as an annular flange 78B, which extends radially outwards from the shaft section 71 and engages in a seal location 56 of the switch housing 33. The seal location 56 comprises for example an annular slot 56B in the side wall 52.

[0103] The seal flange 78 and the seal location 56 also hold the transmission element 70, in respect of the rotation axis D, on the switch housing 33 with longitudinal movement capability. Thus the seal flange 78 and the seal location 56 form shift-lock contours 78A and 56A, which hold the transmission element 70 non-displaceably relative to the rotation axis D, at the through opening 54. The shift-lock contours 78A and 56A engage positively in one another and/or have or form support contours perpendicular to the rotation axis D, so that they hold the transmission element 70 non-displaceably relative to the rotation axis D. However the shift-lock contours 78A and 56A allow rotatability of the transmission element 70 around the rotation axis D relative to the switch housing 33.

[0104] Depending on the respective angular position or switching position MN, ML, MR of the switch actuator 75, for example of the magnet, the switch element 24 assumes various switching positions, with which then for example clockwise or anti-clockwise rotation of the drive motor 16 may be set. The switching positions MN, ML, MR are assigned to the actuating positions N, L, R of the actuating element 32 and/or correlate with these actuating positions. In the switching positions MN, ML, MR, a magnetic field of the switch actuator 75 may penetrate the switch element 24 in different directions, so that the switch element 24 for example is activated for example to output different sensor signals or control signals SIG to a control unit 21A, for example a microcontroller. With the aid of these control signals or sensor signals, the switch element 24 specifies to the control unit 21A that the latter should trigger the power supply unit 21 to supply power to the drive motor 16 for anti-clockwise or clockwise rotation.

[0105] If however no clear direction of rotation is set, i.e. the actuating element 32 adopts a middle or neutral actuating position N and the switch actuator 75 the middle, as it were undefined, switching position MN, then blocking contours 90, 91 ensure that the actuating element 31 cannot be actuated from its actuating position A into one of the actuating positions E. On the other hand, if the actuating element 31 is actuated in one of the actuating positions E, then a change in the direction of rotation of the drive motor 16 is blocked, i.e. the blocking contours 90, 91 prevent any movement of the actuating element 32 out of the actuating position R into the actuating position L and vice-versa when the actuating element 31 is actuated into one of the actuating positions E i.e. a switch-on position of the drive motor 16 is actuated.

[0106] The blocking contours 90, 91 act directly on one another. It is advantageous that the blocking contours 90, 91 do not act directly on the transmission gear 80 or its components. The blocking contours 90, 91 are expediently not in engagement and/or direct contact with the transmission gear 80 or its components and/or the transmission element 70.

[0107] The blocking contours 90, 91 include for example blocking projections 92, 93 on the actuating elements 31, 32. The blocking projection 92 projects for example beyond a top of the actuating element 31 facing the actuating element 32. In particular the blocking projection 92 is designed as a rib. From the actuating element 32, the blocking contour 91 protrudes in the manner of a blocking projection 93. In the actuating position N, the blocking projections 92, 93 strike against each other, so that actuation of the actuating element 31 in the direction of one of the actuating positions E is not possible.

[0108] Next to the blocking projection 92 are open spaces or recesses in which the blocking projection 93 can engage when the actuating element 32 is moved into one of the actuating positions R or L. Then it is possible for actuating element 31 to be moved from actuating position A into one of the actuating positions E. On the other hand, however, it is not then possible for the blocking projection 93 to be actuated past the blocking projection 92 from one of the actuating positions R, L into the respective other actuating position L, R. Then the blocking projection 93 strikes against the sides of blocking projection 92 which extend parallel to the sliding axis S.

[0109] The actuating element 32 may preferably be locked with the aid of a latching arrangement 98. The latching arrangement comprises for example a latching projection 99, immovable relative to the switch housing 33 and/or the machine casing 11, which engages in one of two latching recesses 99R, 99L in the actuating positions R, L.