Rotary switch

FIELD OF THE INVENTION

The present invention relates to a rotary switch and a hand tool having such a rotary switch, in particular a rotary switch to select between two modes of the power tool, such as a percussion operation and a Bohrschlagbetrieb a combination hammer.

DESCRIPTION OF THE PRIOR ART

A rotary switch for actuating an axially movable switching element of a portable power tool is made of <patcit id="pcit0001" dnum="EP1632314A2"><text>EP 1632314 A2</text></patcit> known. At a turning handle an eccentrically arranged parabolic nose is clamped. A spiral spring is suspended outside of the turning handle to a pin. Two spring legs of the coil spring surround the parabolic nose. Moreover, the two spring legs clamp a one projection on the axially displaceable switching element. When rotating the rotary handle each one of the spring leg is deflected through the nose against a spring tension while the nose of the other spring leg solves. The other spring leg exercises while a force on the projection until the axially movable switching element is moved laterally and the other spring leg strikes again on the nose.

The rotary switch according to <patcit id="pcit0002" dnum="EP1632314A2"><text>EP 1632314 A2</text></patcit> while allowing only a coil spring can be realized with the position of the rotary switch, and regardless of the direction of rotation. synchronizing the position of the axially movable switching element However, results in a high assembly effort of the rotary switch, because he can not be placed in a piece on the machine tool. Further, the two spring legs have to be clamped when the spiral spring is mounted.

DISCLOSURE OF THE INVENTION

A task is a rotary switch with a simplified installation option The inventive rotary switch for shifting a switching element includes a rotary handle, a torsion spring, a rotatable actuator and a common axis. The rotary handle, the torsion spring and the rotary actuator are mounted rotatably about the common axis. The rotary handle and the rotatable actuating element are coupled through the torsion spring such that relative rotation of the rotary handle relative to the rotatable adjusting element twists the torsion spring. On the rotatable adjusting element an eccentric is provided for converting a rotational movement of the rotatable actuating element into a displacement of the switching element.

The rotatable adjusting element follows the rotary movement of the rotary handle, so far as the adjusting element is not prevented by the coupled to the eccentric switching element. The rotatable actuator and the rotary handle particles then assume a synchronous position. The relative rotation is to understand one of the synchronous positions of the rotary handle with respect to the actuating element. In the synchronous position, the torsion spring is preferably returned to a rest position with a low or no tension. This is possible because the torsion spring can also rotate about the axis of rotation. A mechanical load of the rotary switch in a synchronous position may therefore be advantageously low.

The common arrangement of the elements on an axis allows prefabrication of the rotary switch, which can then be mounted as a component on a machine tool. In particular, no fastening of the clamping limbs of a spring on a machine tool is required.

In the dependent claims embodiments of the rotary switch are described.

In a development of the twist grip towards the rotary actuator in the negative direction and the positive direction with respect to the rotation axis is rotated. The rotary handle and the rotary actuator each include a stop which has in positive direction with respect to the axis of rotation, and a stop which has in negative direction with respect to the axis of rotation. The torsion spring includes two engagement elements. The engagement elements are arranged over the attacks that at a relative twisting one engagement element applies force with one of the stops of the rotary knob and the other engaging member force applied to one of the stops of the rotary actuating element coupled with the force is applied stop the twist grip and the force is applied stop of the actuating element facing in opposite direction of rotation. The stops thus clamp the torsion spring when the actuating element a rotary motion of the rotary handle can not follow synchronously. The torsion spring may be biased in either direction in the rest position. This allows the switching force can be increased.

One embodiment provides that one of the engaging members coupled with the attacks of the rotary handle and the other engaging member with the attacks of the actuating element or that one of the engaging members coupled with attacks that have in positive direction of rotation, and the other engagement element coupled with attacks which point in negative direction of rotation.

The engaging elements may have a radial extension which extends at least over the first distance and second distance from the axis of rotation. The stops of the rotary handle may in a first distance from the rotation axis may be arranged at a second distance to the rotational axis, the stops of the rotary control element, wherein the first and second distances are different.

In one development, the engagement elements define a continuous circular sector with respect to the axis of rotation, in which all the stops are arranged. In a synchronous position may each one of the stops of the rotary knob and one of the stops of the actuating element in one of the engaging members and the other stop of the rotary handle and the other stop of the actuating element bear against the other engaging member.

A development is characterized by a rotatable bearing, which has a hollow hub and a pin rotatably inserted into the hollow hub. Either can be formed as part of the rotary handle and the pin as part of the rotary actuating element or the hollow hub as part of the rotatable actuating element and the pin as part of the rotary handle the said hollow hub. The rotary handle and / or the rotary actuating element can be integrally manufactured as injection molded parts. Thereby is a simple and compact structure of the rotary switch reachable.

In a machine tool having at least two various drive can be provided for switching between the driving modes an axially shiftable clutch. A selector switch is a rotary switch according to the invention, the eccentric is coupled to the clutch. The switching distances or the distance of the eccentric to the axis may be such that the desired switching positions a connecting line of the eccentric to the axis is parallel to the axial shift path. The selector switch and the spring can thereby be decoupled from axially acting forces.

In a further development of the machine tool, the eccentric to the clutch is coupled by means of a sleeve-like shift linkage. The machine tool may include a cylindrically-shaped drive means, the sleeve-shaped switching linkage engages the drive means. The sleeve-shaped switching linkage ensures a high mechanical stability. The shift linkage can be mounted for rotation about its axis of symmetry with respect to the clutch. The shift linkage, and the clutch can have an annular shape interlockingly for the axial displacement of the clutch by the shift linkage. The shift linkage is thus independent of the rotational position of the clutch pressing this. At the same time, the annular engagement provides a uniform application of force in order to avoid tensions.

The machine tool may comprise a resounding drive and a rotary drive for a tool, wherein the clutch selectively couples the resounding drive and / or the rotary drive to the tool. The machine tool can be in particular a portable power tool, a combination hammer.

The following description illustrates the invention by means of exemplary embodiments and figures. The figures show:

BRIEF DESCRIPTION OF THE FIGURES

<ul><li><figref idrefs="f0001">Fig. 1</figref> a partial section of a combination hammer;</li><li><figref idrefs="f0002">FIG. 2</figref> a plan view of the selector switch,</li><li><figref idrefs="f0002">Fig. 3</figref> a cross-section of the selector switch in a plane AA of <figref idrefs="f0002">Fig. 4</figref>.</li><li><figref idrefs="f0002">Fig. 4</figref> a side view of a selector switch,</li><li><figref idrefs="f0002">Fig. 5</figref> a longitudinal section of the selector in a plane BB of <figref idrefs="f0002">FIG. 2</figref>.</li><li><figref idrefs="f0003">Fig. 6</figref> a longitudinal section through a further selector switch and</li><li><figref idrefs="f0003">Fig. 7</figref> a longitudinal section through a further selector switch.</li></ul>

EMBODIMENTS OF THE INVENTION

Identical or functionally equivalent elements are identified by like reference numerals in the figures, unless otherwise stated.

<figref idrefs="f0001">Fig. 1</figref> shows a detail of a combination hammer 1 in longitudinal section. In a guide tube 2, a striker (not shown) back by a drive mechanism and are reciprocated. The striker strikes an inserted into the tool holder 3 tool (not shown). The tool holder 3 can be rotated by a drive described below about their longitudinal axis. 4 The tool then performs both percussive and rotary motion. An operator can select by a selector switch 10, whether the combination hammer 1, the tool is entirely proposes (percussion mode) or in addition also rotates (Bohrschlagbetrieb).

A drive wheel 6 and a clutch 7 are rotatably mounted to the guide tube. 2 The drive wheel 6 is by a prime mover such as an electric motor, driven via a gear and / or linkage. The clutch 7 is slidably mounted along the longitudinal axis of the fourth The clutch 7 can be pushed in a first position with the drive gear 6 is engaged. The rotation of the drive wheel 6 is then transmitted to the tool holder 3 through the clutch 7th This corresponds to the beating and rotating operating mode of the combination hammer 1. In a second position, the clutch 7 is pulled out of engagement with the drive wheel. 6 In this second position the combination hammer 1 performs only a blow to the tool.

The selection switch 10 moves the coupling 7 between the first and second positions.

The selector switch 10 is designed as a rotary switch having an eccentric eleventh The eccentric 11 engages a lug 12 of a switching element thirteenth The switching element 13 may be designed as a sleeve which surrounds the guide tube 2 radially. The switching element 13 can be displaced along the guide tube. 2 At one end of the eccentric 11 away of the switching element 13 is an annular structure 14 is provided, in which the coupling 7 engages with a corresponding annular structure 15th In that in<figref idrefs="f0001">Fig. 1</figref> Variant shown, the switching element 13, an annular protuberance or hook, which engages in an annular recess of the coupling 7th

The clutch 7 and the drive wheel 6 can be formed as a gear wheel or bevel gear.

A with respect to the longitudinal axis 4 fixed, in particular non-rotatable, detent 16 may be provided. The detent 16 may be formed as a tooth on which the clutch 7 is pushed in the second position. In this way, a rotation of the tool is inhibited.

A spring member 17, the clutch 7 in such a manner acted upon by a force that the coupling is released 7 at a fraction of the switching element 13 of the drive wheel 6, and is optionally slipped onto the locking sixteenth The spring element 17 can be as shown as the clutch 7 pushing spring or as a pulling spring (not shown) may be realized.

Based on <figref idrefs="f0002">Figures 2 to 5</figref> is illustrated an embodiment of the selector 10th <figref idrefs="f0002">Fig. 4</figref> shows a side view, <figref idrefs="f0002">FIG. 2</figref> a plan view, <figref idrefs="f0002">Fig. 3</figref> a cross-section transverse to a rotational axis 21 of the selector switch 10 in the plane AA of <figref idrefs="f0002">Fig. 4 and Fig. 5</figref> a longitudinal section along the rotation axis 21 in the plane BB of <figref idrefs="f0002">Fig. 3</figref>,

An actuating element 22 of the selector switch 10 is formed of the eccentric 11 and a hollow hub 23rd The hollow hub 23 defines an axis of rotation 21 of the selector 10th

A turning handle 24 of the selector 10 has a pin 25 on. The pin 25 is inserted into the hollow hub 23 such that the rotary handle 24 may be rotated relative to the actuating element 22 and thus to the eccentric eleventh

A sleeve 26 can engage around the knob 24th In the turning handle 24, a circumferential groove to be admitted 27 that prevents slipping the cuff 26th The cuff 26 may be used to fix the rotating handle 24 on a housing of the combination hammer first The rotary handle 24 with respect to the sleeve 26 or at least the housing rotatably.

A torsion spring 30 is pushed onto the hollow hub 23rd The torsion spring 30 may be for example a coil spring with one or more turns. The torsion spring 30 has two engaging members 31, 32, which may preferably be formed by angled end portions of the torsion spring 30th The two engaging members 31, 32 can protrude from the torsion spring 30 in the radial direction, such as in<figref idrefs="f0002">Fig. 3</figref> shown. The two engaging members 31, 32 define an angular range 33 within the rotary switch 10 relative to the rotational axis 21. The height of the arrangement of the two engagement elements 31, 32, ie in its direction along the axis of rotation 21, may be different.

The rotary handle 24 includes two stops 34, 35 on which, though arranged at two different angular positions relative to the rotational axis 21, but within the same defined by the attack elements 31, 32 angular range 33. The two stops 34, 35 may be as shown by a protruding segment 36 can be formed, which is arranged in the interior of the rotary handle 24 and extends from the one angular position to the other angular position is formed continuously. Alternatively, two lugs are provided on the respective angular positions. The arrangement of the projecting segment 36 and the lugs in a direction along the rotation axis 21 corresponds to the height of the two engaging elements 31, 32 of the torsion spring 30. The rotary handle 24 is thus configured such that upon rotation about the rotational axis 21 in exactly he a the two engaging members 31, 32 engages. The torsion spring 30 is itself mounted to rotate about the axis of rotation 21st On the one hand, the torsion spring 30 by any engagement with the other of the two engaging members 31, 32 is prevented in its movement, the torsion spring 30 is carried along from the rotation handle 24th On the other hand, the torsion spring 30 at the other engaging member 31, 32 from being detained reasons to be explained by the actuator 22, this leads to a tensioning of the torsion spring 30. The torsion spring 30 can be stretched or compressed depending on the structure in position.

The adjusting element 22 has the same as the rotary handle 24 also stops 37, 38 which are arranged at another angular positions. The other angular positions may correspond to the angular positions of the stops 34, 35 of the rotary handle the 24th The stops 37, 38 of the actuator element 22 are both within the same angular range 33 as the stoppers 34, 35 of the rotary handle 24 with respect to the engaging members 31, 32 of the torsion spring 30 is arranged.

If the rotary handle 24 rotated relative to the actuating element 22, clamping a first of the stops 34, 35 of the rotary handle 24 along with a second of the stoppers 37, 38 of the adjusting element 22 the torsion spring 30. The first stop 34, 35 and the second stop 37, 38 are the most widely within the angular range 33 of each remote attacks.

A user can operate at any time the selector 10th The selector switch 10 has not latched positions shown, in which the rotating handle 24 into place. The detent positions corresponding to the desired operating modes of the combination hammer 1. At the actuator 22, the clutch 7 is coupled. The clutch 7 can initially be restrained from axial movement when the clutch 7 in such a way with respect to the detent 14 or the drive wheel 6 is twisted that they are prevented from engaging each other. The combihammer 1 thus does not change in synchronism with the operation of the selector switch to operating mode. The actuating element 22 follows also hindered by the clutch 7 is not the rotational movement of the rotary knob 24, as a result, the torsion spring 30 is tensioned.

By the drive of the combination hammer 1, the coupling 7 with respect to the locking device 14 and the driving wheel 6 is further rotated. At a certain angular position, a mutual interference is possible. The tensioned torsion spring 30 causes via the eccentric 11, a force to move the clutch 7 axially in the engagement.

Other configurations of the selector switch 10 are possible.

The rotation axis can be formed by a hollow hub of the rotary handle and a pin of the actuating element. The pin is rotatably mounted in the hollow hub. The torsion spring surrounds the pivot axis formed by the hollow hub and the pin.

In a further embodiment, the torsion spring between the hollow hub and the pin is located.

A further embodiment of a selector switch 50 is in longitudinal section in <figref idrefs="f0003">Fig. 6</figref> shown. The selector switch 50 is designed as a rotary switch. The selector switch 50 comprises a rotary handle 51, a rotatable actuating member 52 and a torsion spring 53, which are arranged concentrically to a common axis of rotation 54th In the illustrated embodiment, a pin 55 of the rotary handle 51 forms the rotation axis 54. The rotary actuator 52 has a hollow hub 56, in which the pin 54 of the rotary handle 51 is inserted.

The rotatable actuator 52 has a axis of rotation 54 arranged offset eccentric eleventh

The torsion spring 53 has two engaging members 60, 61st The engaging members 60, 61 are preferably the ends of the torsion spring 53. One of the engaging members 60 is positively or positively with the twist grip 51 and the other of the engaging members 61 is positively or positively coupled to the rotary actuator 52nd The torsion spring 53 is formed such that it can be twisted in both directions of rotation about the rotational axis 54th In one embodiment, the torsion spring 53 is formed as a spiral spring, in which the turns are spaced apart. In addition, the torsion spring 53 applies a force to the knob 51 and the rotary actuator 52 exerts in both cases made such that the torsion spring 53 returns to its rest position.

A further embodiment of the selector switch is in <figref idrefs="f0003">Fig. 7</figref> shown. The torsion spring 73 is offset in height to the hollow hub 75 arranged. The engaging members 76, 77 are in turn coupled to the rotary handle 71 and the rotary actuator 52nd

Instead of the torsion spring to be formed by a separate component, the pin, which is inserted in the hollow hub, be designed as a torsion spring.

The selector switch can be used to operate with his eccentric lever arm.