The present invention relates to an electric hand tool at least comprising the elements, features and components defined in the preamble of the appended single main claim number 1.

Such movable operating elements are substantially known in general, for instance from DE-10.2004.055.236. Known herefrom is a blocking embodied as a slide which acts on a toothed wheel of the transmission on the drive shaft and which can be driven with a cam on an outer side of a rotating disc. For blocking purposes a user has to move the slide to a blocking position counter to a spring force with the rotary knob. When the user releases the slide, the blocking is released and the motor can set the tool holder into motion.

These and other examples of the known art have the shared drawback that the user him/herself has to consciously and deliberately realize an alignment of the blocking or has to wait with running motor to bring about a blocked position with a catch in a notch. A simple selection, operation, setting or control is however very desirable, particularly of the blocking and particularly by and for less experienced users.

The present invention has for its object to provide a solution for, or to at least (considerably) reduce, the above-mentioned and/or other problems and drawbacks of the known art, for which purpose the elements, features and components are additionally provided as defined in the characterizing part of the appended single main claim number 1.

By using curve tracks (as opposed to for instance cams) many functions and functionalities can be actuated, selected, controlled or set using a single operating element, for instance a rotary knob or possibly even a slide element. Followers can then be oriented on a single curve track or on different curve tracks, whereby a plurality of followers can co-act with one or more than one curve track and can each be associated with a different function or functionality. A very compact

configuration with more functions and functionalities can thus be controlled in simple manner - even by a less experienced user - using a single operating element. The configuration with a locking plate with a locking catch or cam which engages round the drive shaft moreover provides the option of realizing a self-actuating locking or blocking. With the blocking catch opposite the operating element a curve oriented and running toward the drive shaft can be pressed away from the drive shaft. A single spring element can be used here to urge the locking plate with the blocking catch toward the drive shaft, wherein the blocking catch acts on the drive shaft only when the curve yields and the spring is able to urge the locking plate with the blocking catch toward the drive shaft. It is thus possible to suffice with a single spring element, and a self-actuating locking is provided which blocks when the drive shaft has taken up a suitable position without a user having to provide for any alignment or other adjustment other than moving the operating element to a position of the operating element corresponding to the blocking position. The operating element is not impeded from taking up this position, and the blocking or locking is then automatically effected as soon as the drive shaft and the blocking catch are aligned in a desired manner.

According to the invention the hand tool has a blocking catch acting on a drive shaft and the blocking catch lies opposite the operating element relative to the drive shaft. The follower is preferably directed toward the operating element here, and a compact and elegantly simple configuration is also found to result here, in which the blocking extends round the drive shaft between the follower and the blocking catch. Even though the distance between the drive shaft and the operating element is small, sufficient space is created to enable application of simple, effective and robust followers and blocking catches without the risk of too many or excessively small and vulnerable components and elements having to be employed, which would be a logical further development of the art known from

DE-10.2004.055.236.

In a preferred embodiment the hand tool can have the feature of having at least two curve tracks and at least two followers. With more than one follower for one of the curve tracks the number of followers can even be greater than the number of curve tracks. At least as many functionalities and functions can thus be set, selected or controlled by a user as the number of curve tracks on the inner side of the operating element.

In a preferred embodiment the hand tool can have the alternative or additional feature that the curve track comprises a guide surface for guiding the follower which varies in height relative to the side of the operating element facing toward the interior of the housing. The curve track or tracks can also comprise a milled track which can be followed by a follower. The variations in (depth or) height along the curve track correspond to adjustments in functions or functionalities which can be selected, controlled and/or set using the operating element. Alternatively, lateral variations relative to a longitudinal direction of a curve track can be defining for this purpose.

In a preferred embodiment the hand tool can have the alternative or additional feature that the operating element is a rotary knob. A rotary knob is per se known, although not in the sense that a rotary knob comprises at least one curve track, and this embodiment results in an extremely compact

configuration, although a slide can also form a usable and useful embodiment of the invention. In the case of a rotary knob it may be advantageous for the curve track to be concentric relative to a rotation axis of the rotary knob. Diverse other curve tracks can then extend at other diametric distances from the rotation axis of the knob, this also contributing toward a compact and elegantly designed combination of many functions and

functionalities .

In an embodiment with a blocking co-acting with the follower it may otherwise also be very advantageous for the blocking to co-act with a resilient element in order to be urged under spring force to a blocking position and to be selectively moved via the follower into or out of the blocking position with the curve track. In such an embodiment the blocking "searches for" the blocking position under the influence of the resilient element as long as or as soon as the position of the follower relative to or along the curve track requires the thus blocking position (as soon as or when the user sets such a position of the operating element or opts to activate the blocking) .

In a preferred embodiment the hand tool can have the alternative or additional feature that the follower is at least connected to or co-acts with a main switch for selectively enabling or disabling a connection of the hand tool to an electrical power supply. As already noted above, the

simultaneous blocking of the movement of the tool and disabling of the connection to the electrical power supply can enhance convenience of use and avoid risks. A manual switch can still always be provided here for a user to selectively switch the motor on and off in an enabled mode of the main switch. The user can then use a knob on for instance a handle of the hand tool in a usual manner to set the hand tool into operation. This manual switch can then also effect a setting of intensity or rotation speed or motor power or, in yet another design, this setting or control can also be realized in the operating element, wherein the manual switch is limited to an on/off function.

In an embodiment with at least two curve tracks, a blocking and a main switch it may be advantageous for the curve track or tracks for the blocking and for the main switch to be embodied such that the power supply is simultaneously disabled via the main switch in a blocking position of the blocking. The purpose hereof has already been elucidated above.

In a preferred embodiment the hand tool can have the alternative or additional feature that the follower is at least connected to or co-acts with a hammer selector for selectively activating and deactivating a vibration or hammer mechanism. The hammer selector for the vibration or hammer mechanism can operate by not switching on this mechanism or by not mechanically connecting this mechanism to the drive or transmission or to the motor. This provides yet another example of another function or functionality of a hand tool which can be set, controlled or selected using the single operating element, without detracting from a compact configuration in combination with an enhanced convenience of use.

In a preferred embodiment the hand tool can have the alternative or additional feature that the follower is at least connected to or co-acts with a screwing or drilling selector for selectively activating and deactivating a screwing or drilling mechanism. The screwing or drilling mechanism can be a single mechanism, the rotation speed and/or an applied motor power of which define ( s ) a desired application . Thus provided is a further example of another function or functionality of a hand tool which can be set, controlled or selected using the single operating element without detracting from the compact configuration in combination with an enhanced convenience of use.

The present invention will be further elucidated hereinbelow on the basis of a description of an exemplary embodiment thereof which is shown in the accompanying drawing, wherein the same reference numerals may be used for the same and/or similar elements, components and aspects, and which is by no means intended to limit the scope of protection of the present invention to specific features shown therein or described hereinbelow, but only to the scope of protection as defined in the likewise appended claims. In the drawing:

Fig. 1 is a perspective view of (a part of) a drill as embodiment of an electric hand tool according to the present invention;

Fig. 2 is a perspective view of a part of a rotary knob facing inward into the drill as embodiment of an operating element according to the present invention;

Fig. 3 is a perspective view of a part of the internal mechanism of a drill such as that in Fig. 1 with a removed rotary knob;

Fig. 4 is a view in even further detail relative to Fig. 3 in which a holder for the rotary knob has been removed;

Fig. 5 is a perspective cross-sectional view of the drill of Fig. 1;

Fig. 6 is a perspective view of particularly a blocking according to the present invention;

Fig. 7 is a perspective view of particularly a vibration or hammer mechanism; and

Fig. 8 is a perspective view of particularly a detail of a main switch.

Fig. 1 shows a drill as possible embodiment of an electric hand tool according to present invention. Drill 1 comprises a housing 2 and a drill chuck 3 as possible embodiment of a tool holder, since a drill can after all be placed and locked therein as embodiment of a tool . As will be further elucidated hereinbelow, housing 2 forms a housing for a motor and a transmission which transmits power from the motor to drill chuck 3. The motor and transmission are not shown in fig. 1. What fig. 1 does show is a rotary knob 4 as embodiment of an operating element according to the present invention.

Fig. 2 shows a view of rotary knob 4 on the side thereof facing toward the interior of housing 2 in the mounted position of rotary knob 4 as shown in fig. 1. Fig. 2 shows that curve tracks 5, 6 and 7 are arranged on the side of rotary knob 4 shown therein. Curve tracks 5 and 6 lie at the same diameter relative to the centre of rotary knob 4, where a hole is arranged to enable fixed mounting of rotary knob 4 on housing 2. Conversely, the third curve track 7 extends at a smaller diameter relative to continuous hole 8. Three curve tracks 5, 6 and 7 are therefore provided in this way on the inward facing side of rotary knob 4. Each of these curve tracks can be used to actuate, control, select or set a specific function or functionality.

In a position mounted against housing 2, follower elements lie against curve tracks 5, 6 and 7. These follower elements can take the form of the cams 9, 10 and 11 shown in fig. 3, which come to lie against the respective curve tracks 5, 6 and 7 when rotary knob 4 of fig. 2 is mounted against and in a cylindrical holder 12 on housing 2 (which is largely broken away in fig. 3) . Cam 9 co-acts here with curve track 5, cam 10 co-acts with curve track 6, and cam 11 co-acts with curve track 7 at a distance from a screw 13, with which knob 4 can be mounted in hole 8 on housing 2, which is shorter than that of cams 9 and 10.

Fig. 2 shows that (at least) curve track 6 comprises a dip 23 as embodiment of a relatively shallow recess. This serves to provide an auditive or tactile indication of having reached a position corresponding to a functionality during turning of the rotary knob. A follower element, for instance cam 10, is received here in dip 23 but does not impede further turning of rotary knob 4. The user will notice from a clicking sound or from a tapping sensation on his or her hand that the knob is being rotated beyond a position associated with one of the possible functionalities. Each of the curve tracks or a selection thereof can comprise one or more than one dip in order to thus provide an indication each time a position associated with a desired functionality or combination of functionalities is reached. Visual indicators are preferably also arranged on housing 2, this not being shown, such as pictograms, for the purpose of visually indicating the associated functionalities to the user.

Figures 4, 5 and 6 show a locking plate 14. An outer end of locking plate 14 forms the cam 10. As shown in Fig. 6, locking plate 14 comprises a central passage through which protrudes a shaft 15 around which a release sleeve 16 is arranged.

Locking plate 14 is pressed by means of a spring 17 in the direction of shaft 15 and of rotary knob 4, wherein spring 17 acts on the part of locking plate 14 lying opposite cam 10 relative to shaft 15 or the passage. A blocking catch embodied as protrusion 18 comes to lie here against locking plate 14 in a recess 19 in shaft 15 in order to lock shaft 15.

Through rotation of rotary knob 4 and an appropriately embodied curve track 6, the cam 10 on locking plate 14, which forms a follower element over curve track 6, is moved laterally in the direction of arrow A in fig. 6. Most clearly caused in fig. 6 is that protrusion 18 moves out of recess 19 in shaft 15 and the locking of shaft 15 is thus released. With further rotation of rotary knob 4 or, conversely, rotation back to a previous position thereof, protrusion 18 will be able to drop once again into recess 19 in shaft 15 in order to restore the locked position . If recess 19 and protrusion 18 are not aligned, only a short rotating movement suffices for protrusion 18 to be received in recess 19 of shaft 15 under the action of spring 17. A self-actuating blocking or locking is thus provided.

In a locked state of the shaft it is very desirable that the motor of drill 1 cannot be activated in any way. If this were to happen, it could result in disruption of the transmission, the motor itself or some other component of the drill. Serving for this purpose is curve track 5 in combination with the cam 9 forming a follower element, which during movement thereof acts on a main switch 20 via an arm 19. When main switch 20 is switched off the motor can no longer be made to function, even with a control knob on the handle of the drill. Curve tracks 5 and 6 are formed such that it is precluded that the motor of drill 1 can be set into operation in a locked state of locking plate 14, acting on shaft 15. This has the additional advantage that a user can safely grip and rotate drill chuck 3 in order to release, through rotation of the drill chuck, a (not shown) engagement arranged therein of a drill bit to be inserted therein. The drill bit can then be safely removed or inserted. There is no risk whatever of the motor then coming into operation, even if the user were to unintentionally touch a control knob for the motor on the handle of drill 1.

Curve track 7 acts on a slide plate 21 which is also pressed toward rotary knob 4 under the influence of the spring force of a spring 22. With a rotation of rotary knob 4 and a desired form of curve track 7, this curve track 7 can press cam 11 aside in order to thus set a hammer and/or vibration mechanism into operation. In an unlocked state of shaft 15 and with power to be supplied to the motor (main switch 20 is switched on) a user can thus opt for a drilling and/or screwing position or a hammer and vibrating position. The hammer and/or vibration mechanism (not shown) can, with its own drive, be set into operation or be mechanically connected to and uncoupled from the transmission between the motor (not shown) of drill 1 and shaft 15 and drill chuck 3. Most usual in the field of drills is for a mechanical and selectively switchable coupling to be applied between the hammer and/or vibration mechanism and shaft 15.

It is thus found that very diverse functions can be set, switched on or off, selected, actuated or controlled with a very compact rotary knob 4. It is even possible to make use of a greater number of height differences of individual curve tracks in order to set adjustable or even varying operational modes, such as those of the motor power to be supplied. This is of course again a setting which is only possible when shaft 15 is free to rotate and is not engaged by locking plate 14, and switch-on of the motor has not been made impossible by means of main switch 20. A higher degree of safety can thus be provided, and functions and/or functionalities which should not be active simultaneously can be mutually precluded by means of a suitable form of the curve tracks, as also indicated and described above. Diverse curve tracks with mutually differing variations in the height thereof can also be provided. Locking plate 14 need thus only be displaced over a distance which is a little greater than the dimensions of cam 18 in order to unlock shaft 15, this distance being determined by an appropriate variation in height of the associated curve track 6. Conversely, the adjustment of another setting can require a displacement over a longer or shorter distance, for which purpose an associated individual curve track must have a matching height variation, which may differ from the variation in height of curve track 6.

Many alternative and additional variants and embodiments will occur to the skilled person after examination of the foregoing. The scope of protection for the present invention is by no means limited to a specific feature shown in the accompanying drawing or described above. Only the definition according to the claims determines the letter or spirit of the scope of protection. The transmission can thus be formed wholly by the drive shaft, which need not even comprise more than a motor shaft of the motor, wherein the tool holder can be arranged on the drive shaft and no further elements or components need be provided other than the motor and the shaft thereof, and the tool holder. The blocking can act here directly on the motor shaft.