EP2949428A2 - Electric tool, in particular a screw-driving tool, with rotation direction switch - Google Patents

Abstract

It is a screwdriver with a drive motor (14) and a Gasgebeschalter (26) indicated with a pusher (28) which is movable against a spring force and can be locked in a closed position, and with a direction of rotation switch (32) for controlling the direction of rotation, wherein the accelerator switch (26) is mechanically coupled to the direction of rotation switch (32) such that the accelerator switch (26) can be locked in a closed position by means of the direction of rotation switch (32).

Description

The invention relates to a power tool, in particular a screwdriver, with a drive motor and a Gasgebeschalter with a pusher which is movable against a spring force and can be locked in a closed position, and with a direction of rotation switch for controlling the direction of rotation.

Such power tools are known in the art. With the accelerator switch, the power tool can be started and, if necessary, the speed set. Especially with drills and screwdrivers a reversal of direction for switching between clockwise and counterclockwise is useful, for which purpose a corresponding direction of rotation switch is provided. In many power tools, a locking of the accelerator switch in its closed position is additionally possible, including an additional actuator is usually provided.

At one of the DE 100 01 459 A1 Known power tool is a Gasgebeschalter and a separate slide switch provided to reverse the direction of rotation. A suitable control circuit ensures that the switch for reversing the direction of rotation does not cause a reversal of the direction of rotation during the running drive. Apparently, this machine also has a locking button for locking the accelerator switch in its closed position.

A disadvantage of such power tools is the use of different controls, which usually requires a two-handed operation required. In addition, the design of the power tool is complicated by the use of different switching elements and increases the susceptibility to interference.

Against this background, the invention has the object to improve a power tool according to the aforementioned type such that the simplest possible locking of the accelerator switch is enabled in a closed position.

This object is achieved with a power tool according to the type mentioned above in that the accelerator switch is mechanically coupled to the direction of rotation switch such that the accelerator switch can be locked in a closed position by means of the direction of rotation switch.

The object of the invention is achieved in this way.

According to the invention the direction of rotation switch is used in addition to the locking of the accelerator switch in a closed position. In this way, a simple one-hand operation can be ensured with a suitable arrangement. Preferably, the arrangement is such that only in the full throttle position of the accelerator switch locking by means of the direction of rotation switch is possible.

According to the invention a simple and reliable construction is ensured and at the same time a safe one-handed operation.

In a further preferred embodiment of the invention, the direction of rotation switch is biased by means of a spring element such that the locking of the accelerator switch in the closed position by actuation of the accelerator switch under the action of the spring element is solvable.

In this way, it is ensured at all times that the locking of the accelerator switch can be canceled by pressing again. This means increased reliability.

According to a further embodiment of the invention, the direction of rotation switch comprises a slide which is arranged in a direction transverse to the direction of movement of the accelerator switch such that the pusher protrudes with a locking lug into a recess of the slider, wherein at least one edge side of the recess an extension, in particular Form of an undercut, is provided, in which the locking tab is movable and lockable in the closed position.

This results in a simple and reliable construction.

According to a further embodiment of the invention, a spring element is provided, which is coupled to the direction of rotation switch in order to act on the locking lug in a locking position in the direction to release the lock.

In this way, a secure release of the locking is ensured upon actuation of the accelerator switch under the action of the spring element.

For this purpose, the spring element by means of a plunger, which is connected to the direction of rotation switch, be biased upon movement of the direction of rotation switch in a locking position.

In this way, the spring element is simultaneously stretched by the movement of the direction of rotation switch in its locking position to automatically cause a release of the lock when pressing the accelerator switch.

In a further embodiment of the invention, a first extension to such an edge side of the recess is provided that a locking of the accelerator switch in the "clockwise" position is possible.

In this way, a locking of the accelerator switch in the preferred working position clockwise is possible.

According to a further embodiment of the invention, a second extension on one of the first extension opposite edge side of the recess is provided, so that a lock in the position "anti-clockwise rotation" is possible.

In this way, both in the right-handed position and in the left-hand rotation position, a locking of the accelerator switch can be made possible in a simple manner.

According to a further embodiment of the invention, a plunger is provided at each end of the spring element, which is coupled to the direction of rotation switch to bias the spring element upon movement in a locking position for clockwise rotation and in a locking position for counterclockwise rotation respectively for releasing the lock.

In this way, a bias of the spring element is ensured in both the right-handed position and the left-hand rotation in a simple manner.

The spring element may in this case preferably be formed as a helical spring, which is held in a spring housing substantially parallel to the direction of movement of the direction of rotation switch.

In this way, a simple tension of the spring element is ensured by a movement of the slide of the direction of rotation switch.

According to a further embodiment of the invention, a locking element is provided on each extension for receiving the locking tab on which the locking tab is held when moving the direction of rotation switch in the locking position under the action of the bias of the accelerator switch and secured against movement of the direction of rotation switch and counteracting operation of the accelerator switch the effect of its bias releasable and releasable from the lock.

In this way, the mechanical locking is ensured in the closed position of the accelerator switch by interaction of the locking element with the locking lug of the direction of rotation switch and at the same time ensures that the lock is released upon actuation of the accelerator switch.

According to a further embodiment of the invention, the direction of rotation switch is coupled in its center position for switching between clockwise and counterclockwise rotation with the accelerator switch, that a movement of the accelerator switch is blocked in a closed position.

In this way, it is ensured that switching on the power tool, when the rotation direction switch is not clearly in a position for clockwise or counterclockwise rotation, a switching is prevented, so as to avoid malfunction.

According to a further embodiment of the invention, the direction of rotation switch is electrically nonfunctional when the accelerator switch is in the on position.

For this purpose, a control is preferably provided which is programmed so that when operating the Gasgebeschalters is first queried whether the direction of rotation switch is in the clockwise or anti-clockwise, then started depending on the position of the direction of rotation switch the engine in clockwise or anticlockwise and preferably according to the position of the direction of rotation switch is controlled in its speed.

More preferably, the controller is programmed so that after starting the engine, the position of the direction of rotation switch for the direction of rotation is no longer relevant.

Once the accelerator switch is actuated so that the motor of the power tool has started, in this way an activation of the direction of rotation switch is prevented, so that malfunctions are avoided.

It is understood that the features of the invention mentioned above and those yet to be explained below can be used not only in the particular combination indicated, but also in other combinations or in isolation, without departing from the scope of the invention.

Fig. 1

ein erfindungsgemäßes Elektrowerkzeug in Form eines Schraubers in seiner Seitenansicht, bei abgenommenem Gehäuseoberteil;

Fig. 2

eine perspektivische Ansicht der aus Gasgebeschaltern und Drehrichtungsschalter gebildeten Schaltereinheit, von der Drückerseite her gesehen;

Fig. 3

die Schaltereinheit gemäß Fig. 2 von der rückseitigen Seite des Drückers aus gesehen, bei betätigtem Drücker, während sich der Drehrichtungsschalter in der Stellung Rechtslauf befindet;

Fig. 4

die Schaltereinheit in ihrer Ausgangsstellung, ohne dass der Gasgebeschalter gedrückt ist, mit dem Drehrichtungsschalter in Mittelstellung;

Fig. 5

die Schaltereinheit gemäß Fig. 4, jedoch bei gedrücktem Gasgebeschalter, mit Arretierschalter in Stellung Linkslauf, jedoch ohne Arretierung;

Fig. 6

die Schaltereinheit gemäß Fig. 5, jedoch arretiert in Stellung Rechtslauf;

Fig. 7

die Schaltereinheit gemäß Fig. 6, wobei jedoch das Federgehäuse teilweise freigeschnitten ist, um die darin aufgenommene Feder erkennbar zu machen;

Fig. 8

eine abgewandelte Ausführung der Schaltereinheit, die sowohl eine Arretierung in der Stellung Rechtslauf als auch in der Stellung Linkslauf ermöglicht, in der Ausgangsposition bei gelöstem Gasgebeschalter und Drehrichtungsschalter in Mittelstellung;

Fig. 9

die Schaltereinheit gemäß Fig. 8 bei gedrücktem Gasgebeschalter und Drehrichtungsschalter in der Stellung Rechtslauf, arretiert in der Vollgasstellung;

Fig. 10

die Schaltereinheit gemäß Fig. 9, in Vollgasstellung, jedoch arretiert in der Stellung Linkslauf;

Fig. 11

die Schaltereinheit gemäß Fig. 10 mit teilweise freigeschnittenem Federgehäuse, um die darin aufgenommene Schraubenfeder erkennbar zu machen und

Fig. 12

die Schaltereinheit gemäß Fig. 11, jedoch in der Stellung Rechtslauf, ohne den Schieber des Drehrichtungsschalters.

Further features and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the drawings. Show it:

Fig. 1

an inventive power tool in the form of a screwdriver in its side view, with the housing upper part removed;

Fig. 2

a perspective view of the switch unit formed from Gasgebeschaltern and direction switch, seen from the pusher side;

Fig. 3

the switch unit according to Fig. 2 seen from the back of the pusher, with the trigger pressed, while the direction switch is in the clockwise position;

Fig. 4

the switch unit in its initial position, without the accelerator switch is pressed, with the direction switch in the middle position;

Fig. 5

the switch unit according to Fig. 4 , but with the trigger switch pressed, with locking switch in the counterclockwise position, but without locking;

Fig. 6

the switch unit according to Fig. 5 , but locked in position clockwise;

Fig. 7

the switch unit according to Fig. 6 but with the spring housing partially cut free to reveal the spring received therein;

Fig. 8

a modified version of the switch unit, which allows both a lock in the clockwise direction and in the counterclockwise position, in the starting position with dissolved accelerator switch and direction switch in the middle position;

Fig. 9

the switch unit according to Fig. 8 with the accelerator switch pressed and direction switch in the clockwise direction, locked in the full throttle position;

Fig. 10

the switch unit according to Fig. 9 , in full throttle position, but locked in the counterclockwise position;

Fig. 11

the switch unit according to Fig. 10 with partially cut spring housing to make the recorded therein coil spring recognizable and

Fig. 12

the switch unit according to Fig. 11 , but in the right-hand position, without the slider of the direction-of-rotation switch.

In Fig. 1 an inventive power tool is shown in the form of a screwdriver and designated overall by the numeral 10. The power tool 10 has a pistol-shaped housing 12, with a center handle 24, on which a Gasgebeschalter 26 is provided with a pusher 28 for actuating an electric motor 14 is. The electric motor 14 is coupled via a gear 16 and a means for torque shutdown upon reaching a predetermined torque with a chuck 20 in which a tool, such as a bit can be clamped. The Abschaltmoment can be adjusted by adjusting an adjustment ring 22 at the outer end of the housing 12. For power supply, an accumulator receptacle 30 is provided at the lower end of the pistol grip 24, to which a rechargeable battery can be interchangeably coupled.

At the transition of the center handle 24 to the upper part of the housing 12, in which the electric motor 14 and the gear 16 are accommodated, a direction of rotation switch 32 is provided, which is designed as a slide switch. By moving the direction of rotation switch 32 to the right, the clockwise position is activated, while the left-hand rotation is activated by a shift of the direction of rotation switch 32 to the left.

The Gasgebeschalter 26 and the direction of rotation switch 32 are mechanically coupled to each other and form a switch unit 25, the in Fig. 2 enlarged in perspective is shown.

While the accelerator switch 26 can be moved by pressing its pusher 28 against the force of a built-in spring element in the direction 34, the direction of rotation switch 32 has a slider 38 which is displaceable in a direction perpendicular to the direction of actuation 34 36. In this case, the slider 38 is arranged directly above the pusher 28 and has a recess 44 in which a push-up element 28 protruding upward from the pusher 28 is movable. On an edge side of the recess 44, an extension 46 is provided in the form of an undercut into which the locking tab 48 can be inserted at a corresponding position of pusher 28 and slider 38 and locked therein.

Fig. 3 shows the switch unit 25 seen from the back of the pusher 28, in befindlichem in full throttle gas trigger switch, with the direction of rotation switch in the clockwise position, but without locking.

The switch unit 25 is received on a base body 40, with which the connection to the housing 12 is made and to which on the opposite side of the pusher 28, a board 42 for the controller 18 of the power tool 10 is received.

The slider 38 cooperates with a spring element 60 in the form of a helical spring, which in a spring housing 52 (FIG. Fig. 12 ) is recorded. The coil spring is actuated via an extension 54 of the slider 38, so that the coil spring in displacement of the slider 38 in Fig. 3 is biased to the right over the plunger 56.

If the slider 38 from the in Fig. 3 shown not locked position further moved to the right, so as to reach its locking position, so so while the coil spring is stretched simultaneously. In the extension 46 in the form of the undercut, which is provided for receiving the locking lug 48 in the locking position, a latching element 50 is further provided on which the locking lug 48 on movement into the locking position and releasing the trigger 28 of the trigger switch 26 under the action of the spring tension the accelerator switch 26 is locked. In this case, the locking tab 48 moves under the spring tension of the accelerator switch 26 to the outside, so that there is a locking on the locking element 50.

If now the gas trigger switch 26 is pressed slightly again after release, the pusher 28 is pressed against the action of the spring tension inwards, so that the locking lug 48 lifts off from the latching element 50. Thus, the lock is released and now the slider 38 is moved under the action of the spring housing enclosed tensioned coil spring back into its release position, so that the pusher 28 of the accelerator switch 26 returns when released in its initial position.

In Fig. 3 to 11 is not the spring housing 52 directly visible, but only the built-over guide 51 of the switch right / left rotation.

In the Fig. 4 to 10 a longitudinal web 58 is additionally shown on the slider 38, which extends in the longitudinal direction of the slider 38 via the recess 44. Furthermore, starting from the middle of the longitudinal web 58, a transverse web 59 can be seen, which extends to the rear in the direction of the spring housing 52. The longitudinal web 58 serves only to stiffen the slider 38 and has no function, since its height is dimensioned so that the locking tab 48 can move freely underneath within the recess 44. However, the cross bar 59 extends further in the direction of the locking lug 58 down so that it blocks an operation of the pusher 28 when the slider 38 is in the middle position between right and left rotation and thus the locking lug 48 immediately in front of the crosspiece 59 is located. Only when the slider 38 is moved from the center position in a direction to the clockwise or counterclockwise rotation, the pusher 28 and thus the accelerator switch 26 can be actuated, since then the locking tab 48 can move laterally along the crosspiece 59. On the representation of the longitudinal web 58 and the crosspiece 59 was in the Fig. 2 and 3 omitted for the sake of easier recognizability of the recess 44.

Fig. 5 shows the switch unit 25 in the clockwise position with the accelerator switch in full throttle position, but in the unlocked position.

Fig. 6 shows the switch unit 25 after moving the slider 38 from the position according to Fig. 5 in the locking position, so that the locking lug 48 is locked in the extension 46 in the form of the undercut.

Fig. 7 shows the switch unit 25 in the same position, but in this case the spring housing 52 is partially cut free, so that the recorded therein coil spring 60 can be seen. In the locking position shown, the coil spring 60 is tensioned by means of the plunger 62.

If now, as already mentioned above, the pusher 28 is actuated again, it will be lifted off the locking element 50, so that the latching is released and the slider 38 under the action of the coil spring 60 from the locking position in the in Fig. 5 shown not locked position moves.

Alternatively, the lock could be released directly by moving the slider 38.

In the Fig. 5 to 12 is a slightly opposite embodiment of the switch unit designated overall by the numeral 25a. Here, corresponding reference numerals are used for corresponding parts.

The only difference to the previously described switch unit 25 is that in addition to the lock in the clockwise direction also a lock in the counterclockwise position is possible. For this purpose, a second extension 66 in the form of an undercut is provided on the edge side of the recess 44 on the opposite side of the first extension 46, whose shape and design completely corresponds to the first extension 46. The second extension 66 makes it possible to lock the slider 38 in the anti-clockwise position as well.

Fig. 8 shows the switch unit 25a in the starting position, ie when the pusher 28 is not actuated and with the slider 38 in the middle position between clockwise and counterclockwise rotation, so that an actuation of the pusher 28 is blocked by the transverse web 59.

Fig. 9 shows the switch unit 25a in the full throttle position with the handle 28 pressed in the clockwise direction, with locking by the engagement of the locking tab 48 in the extension 46th

Fig. 10 shows the switch unit 25a in the full throttle position when the trigger 28 is actuated, locked in the anti-clockwise position by the locking lug 48 engages in the extension 66 in the form of the second undercut and is engaged there by means of the associated locking element.

Fig. 11 shows the switch unit 25a in the same position as at Fig. 10 , ie in the full throttle position when the trigger 28 is actuated and when the locking nose 48 is engaged in the counterclockwise position. In this case, the spring housing 52 is partially cut free, so that the spring element 60 can be seen in the form of the helical spring. The coil spring in this case is tensioned by a plunger 64 connected to the slider 38, which is opposite to the aforementioned plunger 62.

Upon repeated actuation of the pusher 28 thus the locking lug 48 (not shown) is lifted from the associated latching element and moved out of the locked position under the action of the spring element 60, so that the pusher 28 comes back when released to its original position.

Fig. 12 shows the switch unit 25a in the position according to Fig. 11 but with slide 38 removed for better visibility.

For switching between clockwise and counterclockwise rotation, a Hall switch is used, which is actuated by means of a magnet, which is connected to the slide 38. The Hall sensor (not shown) is disposed on the board 42 and cooperates with the magnet (not shown).

The controller 18 of the power tool 10 is constructed such that, starting from the machine in the idle state by actuation of the accelerator switch 26, a start contact for starting the motor 14 is triggered. Subsequently, the controller 18 first queries whether the direction of rotation switch 32 is in the clockwise or anticlockwise position. Only then is the engine 14 started and regulated according to the position of the accelerator switch 26 in its speed. If the pusher 28 pushed so far that the full throttle position results, so the Gasgebeschalter 26 can be locked in the full throttle by the direction of rotation switch 32, since the position of the direction of rotation switch 32 after the start of the motor 14 for the direction of rotation of the motor 14 is no longer relevant ,

Claims (14)

Power tool, in particular screwdriver with a drive motor and a gas trigger switch (26) with a pusher (28) which is movable against a spring force and can be locked in a closed position, and with a direction of rotation switch (32) for controlling the direction of rotation, characterized in that Gas Gebeschalters (26) with the direction of rotation switch (32) is mechanically coupled so that the accelerator switch (26) in a closed position by means of the direction of rotation switch (32) can be locked. Power tool according to claim 1, characterized in that the direction of rotation switch (32) is biased by means of a spring element such that the locking of the accelerator switch (26) in the closed position by actuation of the accelerator switch (26) under the action of the spring element is solvable. Power tool according to claim 1 or 2, characterized in that the direction of rotation switch (32) comprises a slide (36) which is arranged in a direction (36) transversely to the direction of movement (34) of the gas trigger switch (26) such that the pusher (28 ) protrudes with a locking lug (48) into a recess (44) of the slider (36), wherein on at least one edge side of the recess (44) an extension (46), in particular in the form of an undercut, is provided, into which the locking lug ( 48) is movable and lockable in the closed position. Power tool according to claim 3, characterized by a spring element (60), which is coupled to the direction of rotation switch (32) to bias the locking lug (48) in a locking position in the direction to release the lock. Power tool according to claim 4, characterized in that the spring element (60) by means of a plunger (62, 64) connected to the direction of rotation switch (32) is, upon movement of the direction of rotation switch (32) is prestressed into a locking position. Power tool according to claim 4 or 5, characterized in that a first extension (46) on such an edge side of the recess (44) is provided, that a locking of the accelerator switch (26) in the position clockwise is possible. Power tool according to claim 6, characterized in that a second extension to one of the first extension (46) opposite the edge side of the recess (44) is provided, so that a lock in the position left-hand rotation is possible. Power tool according to claim 7, characterized in that at each end of the spring element (60), a plunger (62, 64) is provided, which is coupled to the direction of rotation switch (32) to the spring element (60) when moving into a locking position for clockwise rotation and to bias in a locking position for anti-clockwise rotation in each case for releasing the lock. Power tool according to one of claims 4 to 8, characterized in that the spring element (60) is designed as a helical spring which is held in a spring housing (52) substantially parallel to the direction of movement (36) of the direction of rotation switch (32). Power tool according to one of claims 3 to 9, characterized in that on each extension (46, 66) for receiving the locking lug (48), a latching element (50) is provided, on which the locking lug (48) upon displacement of the direction of rotation switch (32). held in the locking position under the action of the bias of the Gasgebeschalters (26) and against movement of the direction of rotation switch (32) is secured and releasable against the action of its bias on actuation of the Gasgebeschalters (26) and releasable from the lock. Power tool according to one of the preceding claims, that the direction of rotation switch (32) in its center position for switching between clockwise and counterclockwise rotation is so coupled to the accelerator switch (26) that a movement of the accelerator switch (26) is blocked in a closed position. Power tool according to one of the preceding claims, characterized in that the direction-of-rotation switch (32) is electrically non-functional when the gas-fired switch (26) is in the switched-on position. Power tool according to one of the preceding claims, characterized in that a controller (18) is provided, which is programmed so that when operating the Gasgebeschalters (26) is first queried whether the direction of rotation switch (32) is in the clockwise or anti-clockwise position, then, depending on the position of the direction of rotation switch (32), the motor is started in clockwise or anti-clockwise rotation and is preferably regulated in its speed. Power tool according to claim 13, characterized in that the controller (18) is programmed such that after starting the motor (14) the position of the direction of rotation switch (32) is no longer relevant to the direction of rotation.

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