Quick clamping device for at least one rotationally drivable drive shaft having a portable machine tool, in particular an angle grinding machine

Abstract

A quick clamping device for a portable machine tool includes at least one drive shaft, at least one clamping unit, and at least one operating unit. The clamping unit has, for tool-less fastening of an insertion tool on the drive shaft, at least one clamping element for exerting a clamping force on the insertion tool in a clamping position. The operating unit is configured to move the clamping element into a release position, and includes at least one operating element, in particular an operating lever. The operating element has at least one activation surface for movement of the clamping element into the release position. The activation surface is arranged such that at least one force initiation point of the operating element is movable, upon interaction with a contact surface of an actuating element of the operating unit, as a factor of movement of the operating element on the contact surface.

Claims

1. A quick clamping device for a portable power tool, comprising: at least one output shaft configured to be driven in rotation; at least one clamping unit including at least one movably mounted clamping element configured to exert a clamping force on an insert tool unit in a clamping position of the at least one movably mounted clamping element, the at least one clamping unit configured for fixing the insert tool unit to the at least one output shaft without use of tools; and at least one operator control unit at least configured to move the at least one movably mounted clamping element into a release position, the at least one operator control unit including at least one movably mounted operator control element a movably mounted actuating element, and at least one actuating surface, the at least one actuating surface configured for movement of the at least one movably mounted clamping element into the release position and arranged such that, during an interaction with a contact surface of the movably mounted actuating element, at least one force introduction point of the at least one movably mounted operator control element is movable on the contact surface in a manner dependent on a movement of the at least one movably mounted operator control element, wherein the at least one movably mounted operator control element has a first movement axis and includes at least two operator control surfaces arranged on mutually averted sides of the at least one movably mounted operator control element along a direction running at least substantially perpendicular to the first movement axis, and a first control surface of the at least two control surfaces is configured to cause a movement of the at least one actuating surface into contact with the contact surface as a result of a compressive force applied to the first control surface toward the contact surface.

2. The quick clamping device as claimed in claim 1, wherein the first movement axis is offset relative to a second movement axis of the movably mounted actuating element.

3. The quick clamping device of claim 2, wherein: the first movement axis is a pivot axis; and the first movement axis is skewed relative to the second movement axis.

4. The quick clamping device as claimed in claim 1, wherein: a straight line running through the first movement axis and the at least one force introduction point encloses, along with the contact surface of the movably mounted actuating element, an angle in an angle range from 35° to 85°, in a plane running at least substantially perpendicular to the movement axis of the at least one movably mounted operator control element, in a manner dependent on an actuation position of the at least one movably mounted operator control element.

5. The quick clamping device as claimed in claim 1, wherein the at least one force introduction point is movable along a straight line on the contact surface owing to a movement of the at least one movably mounted operator control element.

6. The quick clamping device as claimed in claim 5, wherein the at least one force introduction point is movable along the straight line at least substantially over a maximum extent of the contact surface owing to the movement of the at least one movably mounted operator control element.

7. The quick clamping device as claimed in claim 1, wherein the at least one movably mounted operator control element is pivotably mounted and has a minimum idle travel angle of greater than 5°.

8. The quick clamping device as claimed in claim 1, wherein: the at least one movably mounted operator control element includes at least one stop surface arranged adjacent to the at least one actuating surface on the at least one movably mounted operator control element; and the at least one stop surface limits a maximum movement of the at least one movably mounted operator control element.

9. The quick clamping device of claim 8, wherein the maximum movement is a maximum travel angle.

10. The quick clamping device of claim 1, wherein the portable power tool is an angle grinder.

11. The quick clamping device of claim 1, wherein the at least one movably mounted operator control element is a movably mounted operator control lever.

12. A portable power tool, comprising: a quick clamping device including: at least one output shaft configured to be driven in rotation; at least one clamping unit including at least one movably mounted clamping element configured to exert a clamping force on an insert tool unit in a clamping position of the at least one movably mounted clamping element, the at least one clamping unit configured for fixing the insert tool unit to the at least one output shaft without use of tools; and at least one operator control unit at least configured to move the at least one movably mounted clamping element into a release position, the at least one operator control unit including at least one movably mounted operator control element, a movably mounted actuating element, and at least one actuating surface, the at least one actuating surface configured for movement of the at least one movably mounted clamping element into the release position and arranged such that, during an interaction with a contact surface of the movably mounted actuating element, at least one force introduction point of the at least one movably mounted operator control element is movable on the contact surface in a manner dependent on a movement of the at least one movably mounted operator control element, wherein the at least one movably mounted operator control element has a first movement axis and includes at least two operator control surfaces arranged on mutually averted sides of the at least one movably mounted operator control element along a direction running at least substantially perpendicular to the first movement axis, and a first control surface of the at least two control surfaces is configured to cause a movement of the at least one actuating surface into contact with the contact surface as a result of a compressive force applied to the first control surface toward the contact surface.

13. The portable power tool as claimed in claim 12, further comprising: at least one gearing housing arranged in a vicinity of at least one ventilation opening of the at least one gearing housing, wherein the at least one movably mounted operator control element is movably mounted on the at least one gearing housing, and wherein, at least in a non-actuated state, the at least one movably mounted operator control element is arranged on the at least one gearing housing so as to at least substantially not overlap the at least one ventilation opening.

14. The portable power tool as claimed in claim 12, wherein the portable power tool is an angle grinder.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages will emerge from the following description of the drawing. The drawing illustrates an exemplary embodiment of the disclosure. The drawing, the description and the claims contain numerous features in combination. A person skilled in the art will expediently also consider the features individually and combine them to form meaningful further combinations.

(2) In the drawing:

(3) FIG. 1 shows a portable power tool according to the disclosure having a quick clamping device according to the disclosure in a schematic illustration,

(4) FIG. 2 shows a sectional view of the portable power tool according to the disclosure and of the quick clamping device according to the disclosure in a schematic illustration,

(5) FIG. 3 shows a detail view of an operator control unit of the quick clamping device according to the disclosure, wherein an operator control element is arranged in a contact position of the operator control element, in a schematic illustration,

(6) FIG. 4 shows a detail view of an operator control unit of the quick clamping device according to the disclosure, wherein an operator control element is arranged in an end position of the operator control element, in a schematic illustration,

(7) FIG. 5 shows a detail view of the operator control element, which is arranged, in a manner preloaded by means of a spring force of a spring element, on a gearing housing of the portable power tool according to the disclosure, in a schematic illustration,

(8) FIG. 6 shows an exploded view of the operator control element in a schematic illustration, and

(9) FIG. 7 shows a force diagram of an operator control element force of the operator control element in a schematic illustration.

DETAILED DESCRIPTION

(10) FIG. 1 shows a portable power tool 14 which is designed as an angle grinder and which has a quick clamping device 10. It is however also conceivable for the portable power tool 14 to be of some other design that appears expedient to a person skilled in the art, for example designed as a circular saw, as a grinder or the like. The portable power tool 14 comprises a gearing housing 54 for accommodating and/or for the mounting of a gearing unit 58 of the portable power tool 14. The gearing housing 54 is preferably formed from a metallic material. It is however also conceivable for the gearing housing 54 to be formed from some other material that appears expedient to a person skilled in the art, for example from plastic or the like. The gearing unit 58 is preferably designed as an angle gearing. The gearing unit 58 comprises in particular an output shaft 12 which can be driven in rotation and to which an insert tool unit 18 can be fixed, in particular by means of the quick clamping device 10. The output shaft 12 is preferably designed as a hollow spindle, in which the quick clamping device 10 is at least partially arranged (FIG. 2). A protective cover unit (not illustrated in any more detail here) can be arranged, in a manner already known to a person skilled in the art, on the gearing housing 54. An auxiliary handle (not illustrated in any more detail here) can be arranged, in a manner already known to a person skilled in the art, on the gearing housing 54. The portable power tool 14 comprises a motor housing 60 for accommodating and/or for the mounting of a drive unit 62 of the portable power tool 14. The drive unit 62 is preferably provided, in a manner already known to a person skilled in the art, for driving the output shaft 12 in rotation about an axis of rotation 64 of the output shaft 12 by interaction with the gearing unit 58. The axis of rotation 64 of the output shaft 12 runs at least substantially perpendicular to a drive axis 66 of the drive unit 62. The drive unit 62 is preferably designed as an electric motor unit. It is however also conceivable for the drive unit 62 to be of some other design that appears expedient to a person skilled in the art, for example designed as a combustion-type drive unit, as a hybrid drive unit, as a pneumatic drive unit or the like.

(11) FIG. 2 shows a sectional view of the portable power tool 14, in particular in the region of the gearing housing 54, and of the quick clamping device 10. The quick clamping device 10 for the portable power tool 14, which has at least the output shaft 12 that can be driven in rotation, comprises at least one clamping unit 16, which, for tool-free fixing of the insert tool unit 18 to the output shaft 12, has at least one movably mounted clamping element 20, 22 for the action of a clamping force on the insert tool unit 18 in a clamping position of the clamping element 20, 22. Furthermore, the quick clamping device 10 comprises at least one operator control unit 24 at least for moving the clamping element 20, 22 into a release position of the clamping element 20, 22, which operator control unit has at least one movably mounted operator control element 26, in particular a movably mounted operator control lever. The clamping unit 16 comprises at least two movably mounted clamping elements 20, 22. It is however also conceivable for the clamping unit 16 to comprise a number of clamping elements 20, 22 other than two. The at least two clamping elements 20, 22 have an at least substantially analogous design, such that features disclosed with regard to one of the clamping elements 20, 22 are to be regarded as likewise disclosed for the further clamping element 20, 22. The at least two clamping elements 20, 22 are pivotably mounted. A pivot axis 68 of the clamping elements 20, 22, in particular of the at least two clamping elements 20, 22, runs at least substantially perpendicular to the axis of rotation 64 of the output shaft 12. The at least two clamping elements 20, 22 are provided for fixing the insert tool unit 18, in a state in which it is arranged on the clamping unit 16 and/or the output shaft 12, axially on the output shaft 12, in particular in the clamping position of the at least two clamping elements 20, 22. The at least two clamping elements 20, 22 are connected rotationally conjointly to the output shaft 12. The at least two clamping elements 20, 22 can be driven in rotation about the axis of rotation 64 together with the output shaft 12.

(12) The clamping unit 16 comprises, for a transmission of torque to the insert tool unit 18, at least one rotary driving element 70. In a state in which the insert tool unit 18 is arranged on the clamping unit 16 and/or the output shaft 12, the rotary driving element 70 engages into a receiving recess (not illustrated in any more detail here) of the insert tool unit 18 and, for a transmission of torque, bears against at least one edge, which delimits the receiving recess, of the insert tool unit 18. A transmission of torque between the output shaft 12 and the insert tool unit 18 arranged on the clamping unit 16 and/or the output shaft 12 is preferably realized, in a manner already known to a person skilled in the art, by means of a positive locking connection between the rotary driving element 70 and the insert tool unit 18. The rotary driving element 70 is arranged rotationally conjointly on the output shaft 12. The rotary driving element 70 can be driven in rotation about the axis of rotation 64 together with the output shaft 12.

(13) The operator control unit 24 is preferably provided for moving the clamping element 20, 22, in particular the at least two clamping elements 20, 22, at least into the release position, in which the insert tool unit 18 is removable from the clamping unit 16 and/or from the output shaft 12. Alternatively or in addition, it is conceivable for the operator control unit 24 to be provided for moving the clamping element 20, 22, in particular the at least two clamping elements 20, 22, at least into the clamping position, in which the insert tool unit 18 is fixable by means of the clamping unit 16 to the output shaft 12. The operator control unit 24 preferably comprises at least the operator control element 26, which is actuatable by an operator. The operator control element 26 is designed as an operator control lever. The operator control element 26 comprises a movement axis 36, in particular a pivot axis, which runs transversely, in particular at least substantially perpendicularly, with respect to the axis of rotation 64 of the output shaft 12. The operator control element 26 is preferably mounted so as to be pivotable about the movement axis 36, in particular pivot axis, of the operator control element 26. The operator control element 26 is decoupled from a rotational movement of the output shaft 12. The operator control element 26 is mounted movably on the gearing housing 54 and is arranged in the vicinity of at least one ventilation opening 56 of the gearing housing 54, wherein the operator control element 26 is, at least in a non-actuated state, in particular in a rest position of the operator control element 26, arranged on the gearing housing 54 so as to at least substantially not overlap the ventilation opening. The operator control element 26 is movable partially into a recess 76 of the gearing housing 54. An actuating element 34 of the operator control unit 24, which is actuatable and/or movable by means of the operator control element 26, extends at least partially into the recess 76. For cleaning of the recess 76, it is conceivable for dirt to be able to be at least partially conveyed out of the recess 76 by means of an eccentric portion 72 of the operator control element 26 owing to a movement of the operator control element 26 about a movement axis 36 of the operator control element 26. It is conceivable for the operator control element 26 to have at least one brush element which is arranged on the eccentric portion 72 and which is provided for sweeping out the recess 76 owing to a movement of the operator control element 26. It is also conceivable for the at least one ventilation opening 56 to be arranged on the gearing housing 54 such that an air stream emerging from the ventilation opening 56 can be utilized for cleaning the recess 76.

(14) The clamping element 20, 22, in particular the clamping elements 20, 22, is/are mounted movably, in particular pivotably, on the output shaft 12, in particular in the output shaft 12. The pivot axis 68 of the clamping element 20, 22, in particular of the clamping elements 20, 22, runs preferably at least substantially perpendicular to the clamping axis 78 of the clamping unit 16a. The clamping element 20, 22, in particular the clamping elements 20, 22, has/have at least one motion slotted-guide element which is provided for interacting with a slotted-guide engagement element of the clamping unit 16. The slotted-guide engagement element is fixed to a transmission element 100 of the clamping unit 16. The slotted-guide engagement element is designed as a bolt which is fixed to the transmission element 100, in particular between two fork ends of the transmission element 100. Owing to an interaction of the slotted-guide engagement element and of the motion slotted-guide element, the clamping element 20, 22, in particular the clamping elements 20, 22, is/are movable from the clamping position into the release position or from the release position into the clamping position. The clamping element 20, 22, in particular the clamping elements 20, 22, is/are in particular movable from the release position into the clamping position by means of an action of a spring force of a clamping spring element 102 of the clamping unit 16 on the transmission element 100. The clamping element 20, 22, in particular the clamping elements 20, 22, is/are movable into the clamping position automatically, in particular after withdrawal of an action of a force exerted by an operator by means of the operator control unit 24, owing to an action of a spring force of the clamping spring element 102.

(15) The quick clamping device 10 comprises at least one decoupling unit 86 which is provided for decoupling the operator control unit 24 from the clamping unit 16 in a manner dependent on a rotational speed of the output shaft 12. The decoupling unit 86 is designed such that a relative movement occurs between at least one decoupling element 94 of the decoupling unit 86 and at least the actuating element 34 of the operator control unit 24, for the purposes of decoupling of the operator control unit 24 from the clamping unit 16, in a manner dependent on a rotational speed of the output shaft 12. The decoupling unit 86 comprises at least the movably mounted decoupling element 94 which can be transferred into a decoupling position, in which the operator control unit 24 is decoupled from the clamping unit 16, in a manner dependent on a rotational speed of the output shaft 12. The decoupling unit 86 is preferably designed as a friction-type decoupling unit. The decoupling unit 86 has at least the movably mounted decoupling element 94, which is movable relative to the output shaft 12 owing to a friction force between the decoupling element 94 and the actuating element 34 of the operator control unit 24. The decoupling unit 86 has at least the movably mounted decoupling element 94, which is mounted in the output shaft 12 so as to be movable along and/or around the axis of rotation 64 of the output shaft 12. The decoupling unit 86 comprises at least the movably mounted decoupling element 94 and at least one decoupling spring element 96, which acts on the decoupling element 94 with a spring force in the direction of the operator control unit 24. The decoupling unit 86 has at least the movably mounted decoupling element 94 and at least one slotted-guide element 98 for guiding the decoupling element 94 during a relative movement of the decoupling element 94 with respect to the output shaft 12.

(16) The decoupling element 94 can be placed in contact with the actuating element 34 by means of a non-positively locking connection, or the decoupling element 94 is in contact with the actuating element 34 by means of a non-positively locking connection. The decoupling element 94 is preferably mounted, in particular in the output shaft or in the transmission element 100 of the clamping unit 16, so as to be movable in translational fashion along the axis of rotation 64. The decoupling element 94 comprises in particular a conical connection region which engages at least partially into a recess of the actuating element 34. A friction action between the actuating element 34 and the decoupling element 94 is in particular dependent on a design of the conical connecting region and on a spring force of the decoupling spring element 96. The decoupling spring element 96 is provided for acting on the decoupling element 94 with a spring force in the direction of the actuating element 34. The decoupling spring element 96 is arranged in the transmission element 100 of the clamping unit 16. The transmission element 100 is designed as a clamping fork. The transmission element 100 is connected rotationally conjointly to the output element 12. The transmission element 100 is movable in translational fashion along a clamping axis 78 of the clamping unit 16. The transmission element 100 is mounted movably in the output shaft 12. The transmission element 100 can, at least by means of a clamping spring element 102 of the clamping unit 16, be acted on with a spring force along the clamping axis 78, in particular in the direction of the operator control unit 24.

(17) The decoupling unit 86 has at least one connecting element 104 which is provided for connecting the decoupling element 94 and the transmission element 100 to one another in terms of movement, in particular at least in a state of the output shaft 12 at a low rotational speed or when the output shaft 12 is at a standstill. The connecting element 104 is designed as a bolt. The connecting element 104 is arranged on, in particular fixed to, the decoupling element 94. The connecting element 104 is movable together with the decoupling element 94. The connecting element 104 extends into the slotted-guide element 98 of the decoupling unit 86 (FIG. 2). The slotted-guide element 98 is designed as a slotted-guide track. The slotted-guide element 98 is arranged on the transmission element 100, in particular is formed integrally with the transmission element 100. During a rotational movement of the output shaft 12, the decoupling element 94 and the connecting element 104 are rotatable relative to the transmission element 100 owing to a braking action resulting from an actuation of the actuating element 34, wherein the connecting element 104 is movable in the slotted guide element 98, formed as slotted-guide track, such that the decoupling element 94 is movable counter to a spring force of the decoupling spring element 96 into a guide recess 106 of the transmission element 100. An actuation of the operator control element 26 during a rotational movement of the output shaft 12 can be converted into a movement of the actuating element 34 and of the decoupling element 94 relative to the transmission element 100. A movement of the transmission element 100 resulting from an action of a force exerted by an operator by means of the operator control unit 24 for the purposes of transferring the clamping element 20, 22, in particular the clamping elements 20, 22, from the clamping position into the release position can be substantially prevented during a rotational movement of the output shaft 12. When the output shaft 12 is at a low rotational speed or when the output shaft 12 is at a standstill, an axial force exerted by the actuating element 34 on the decoupling element 94 can be transmitted to the transmission element 100 by means of an interaction of the connecting element 104 and the slotted-guide element 98 designed as slotted-guide track. The transmission element 100 is movable by means of the operator control unit 24 counter to a spring force of the clamping spring element 102. The transmission element 100 is provided for moving the clamping element 20, 22, in particular the clamping elements 20, 22, from the clamping position into the release position.

(18) The operator control element 26 comprises the eccentric portion 72 for an actuation of the actuating element 34 of the operator control unit 24. The actuating element 34 is mounted so as to be movable in translational fashion along the axis of rotation 64, in particular in the output shaft 12 and/or in the gearing housing 54. The actuating element 34 is fixed in the gearing housing 54 so as to be prevented from rotating relative to the gearing housing 54, in particular owing to at least one lateral flattened portion of the actuating element 34, which permits an axial movement and prevents a rotational movement. Preferably, the actuating element 34 has in each case at least one flattened portion at two mutually averted sides of the actuating element 34. It is however also conceivable for the actuating element 34 to be of some other design that appears expedient to a person skilled in the art, for example to have a polygonal cross section, a toothing or the like, which is provided for securing the actuating element 34 against rotation relative to the gearing housing 54. In the region of the actuating element 34, there is preferably arranged a seal element 74, for example a rubber seal or the like, in particular for at least substantially preventing an ingress of dirt into the gearing housing 54 and/or into the clamping unit 16. The seal element 74 preferably bears against the actuating element 34. The actuating element 34 is in particular mounted so as to be movable relative to the seal element 74. The actuating element 34 slides on at least one sealing surface of the seal element 74 during a movement relative to the seal element 74.

(19) For a movement of the clamping element 20, 22, in particular of the clamping elements 20, 22, into the release position, the operator control element 26 has at least one actuating surface 28 which is arranged such that at least one force introduction point 30 of the operator control element 26 during an interaction with a contact surface 32 of a movably mounted actuating element of the operator control unit 24 is movable on the contact surface 32 in a manner dependent on a movement of the operator control element 26 (cf. FIGS. 3 and 4). The actuating surface 28 of the operator control element 26 is preferably arranged on an eccentric portion 72 of the operator control element 26. During an interaction of the actuating surface 28 of the operator control element 26 and the contact surface 32 of the actuating element 34, there is preferably linear contact between the actuating surface 28 of the operator control element 26 and the contact surface 32 of the actuating element 34. The at least one force introduction point 30 of the operator control element 26 is preferably arranged on a contact line of the actuating surface 28 of the operator control element 26. There is preferably linear contact between the actuating surface 28 of the operator control element 26 and the contact surface 32 of the actuating element 34 along the contact line of the actuating surface 28 of the operator control element 26 during an interaction of the actuating surface 28 of the operator control element 26 and the contact surface 32 of the actuating element 34. It is however also conceivable that, during an interaction of the actuating surface 28 of the operator control element 26 and the contact surface 32 of the actuating element 34, there is punctiform contact, wherein the punctiform contact occurs at the at least one force introduction point 30 of the operator control element 26. The at least one force introduction point 30 of the operator control element 26 is preferably formed by a contact point of the actuating surface 28 of the operator control element 26, which contact point is provided for bearing against the contact surface 32 of the actuating element 34 during an interaction of the actuating surface 28 of the operator control element 26 and the contact surface 32 of the actuating element 34 (FIGS. 3 and 4).

(20) The operator control element 26 has the movement axis 36, in particular a pivot axis, which is arranged so as to be offset, in particular skewed, relative to a movement axis 38 of the actuating element 34. The movement axis 38 of the actuating element 34 runs preferably at least substantially parallel, in particular coaxially, with respect to a clamping axis 78 of the clamping unit 16 and/or with respect to the axis of rotation 64 of the output shaft 12. The clamping axis 78 runs preferably at least substantially parallel, in particular coaxially, with respect to the axis of rotation 64 of the output shaft 12. The operator control element 26 has the movement axis 36, wherein a straight line 40 running through the movement axis 36 of the operator control element 26 and the force introduction point 30 encloses an angle 42 in an angle range from 35° to 85°, in a plane running at least substantially perpendicular to the movement axis 36 of the operator control element 26, with the contact surface 32 of the actuating element 34 in a manner dependent on an actuation position and/or movement position of the operator control element 26 (FIGS. 3 and 4). Preferably, in an actuating position and/or movement position of the operator control element 26, in which the operator control element 26 has been moved from a rest position of the operator control element 26 (FIG. 2) into a contact position of the operator control element 26 (FIG. 3), the straight line 40 running through the movement axis 36 of the operator control element 26 and the force introduction point 30 encloses an angle 42 of less than 50° and greater than 35°, in particular an angle 42 with a value of 40°, with the contact surface 32 of the actuating element 34 (FIG. 3). In the contact position of the operator control element 26, the actuating surface 28 preferably bears against the contact surface 32, wherein the actuating element 34 has not been moved along the movement axis 38 of the actuating element 34 by the operator control element 26. Preferably, in an actuating position of the operator control element 26, in which the operator control element 26 has been moved from the rest position (FIGS. 2 and 5) or from the contact position (FIG. 3) into an end position of the operator control element 26 (FIG. 4), the straight line 40 running through the movement axis 36 of the operator control element 26 and the force introduction point 30 encloses an angle 42 of less than 90° and greater than 70°, in particular an angle 42 with a value of 80°, with the contact surface 32 of the actuating element 34. In the end position of the operator control element 26, the actuating surface 28 preferably bears against the contact surface 32, wherein the actuating element 34 has been moved along the movement axis 38 of the actuating element 34 to a maximum extent by means of the operator control element 26.

(21) The force introduction point 30 is movable along a straight line on the contact surface 32 owing to a movement of the operator control element 26, in particular in the event of a movement of the operator control element 26 from the contact position of the operator control element 26 into the end position of the operator control element 26. The force introduction point 30 is movable along a straight line on the contact surface 32 at least substantially over a maximum extent 44 of the contact surface 32 owing to a movement of the operator control element 26, in particular in the event of a movement of the operator control element 26 from the contact position of the operator control element 26 into the end position of the operator control element 26. The operator control element 26 is mounted in pivotable fashion and has a minimum idle travel angle 46 of greater than 5°. The operator control element 26 preferably has a maximum idle travel angle 46 of less than 20°, in particular of 18°. The maximum idle travel angle 46 is an angle through which the operator control element 26 is movable during a pivoting movement of the operator control element 26 from the rest position (FIGS. 2 and 5) into the contact position (FIG. 3). The operator control element 26 has at least one stop surface 48 which limits a maximum movement, in particular a maximum travel angle, of the operator control element 26 and is arranged adjacent to the actuating surface 28 on the operator control element 26. The stop surface 48 is preferably provided to, in the end position of the operator control element 26, bear against the gearing housing 54 in order to limit a maximum movement, in particular a maximum travel angle, of the operator control element 26. The operator control element 26 has the movement axis 36, in particular a pivot axis, and has at least two operator control surfaces 50, 52 which are arranged on mutually averted sides of the operator control element 26 along a direction running at least substantially perpendicular to the movement axis 36 of the operator control element 26. One of the at least two operator control surfaces 50, 52 is provided for the exertion of a force by an operator for a movement of the operator control element 26 from the rest position (FIGS. 2 and 5) into the contact position (FIG. 3), in particular owing to a pressure force being exerted by an operator on at least one of the two operator control surfaces 50, 52. One of the at least two operator control surfaces 50, 52 is provided for the exertion of a force by an operator for a movement of the operator control element 26 from the contact position (FIG. 3) into the end position (FIG. 4), in particular owing to the exertion of a pulling force by an operator on the one of the at least two operator control surfaces 50, 52.

(22) The operator control unit 24 comprises at least one spring element 80 which acts on the operator control element 26 with a spring force in the direction of the rest position (FIGS. 2 and 5) of the operator control element 26 (FIGS. 5 and 6). The spring element 80 is designed preferably as a torsion spring, in particular as a leg spring. The spring element 80 is supported with one end on the operator control element 26, and the spring element 80 is supported with a further end on the gearing housing 54 (FIG. 6). The spring element 80 is provided for acting on the operator control element 26 with a spring force around the movement axis 36 of the operator control element 26. The spring element 80 is preferably arranged in a region of a bearing recess 82 of the operator control element 26. The spring element 80 is provided for provisionally fixing the eccentric portion 72 of the operator control element 26 on a main body 84 of the operator control element 26 during installation of the operator control element 26. In a state of the operator control element 26 and of the spring element 80 in which these are arranged on the gearing housing 54, the spring element is provided for returning the operator control element 26 into the rest position and/or for holding the operator control element 26 in the rest position. The main body 84 is formed preferably from a plastic or from an elastomer. The eccentric portion 72 is formed preferably from a metallic material. The operator control surfaces 50, 52 are arranged on the main body 84. Furthermore, the main body 84, in the rest position (FIGS. 2 and 5), bears against the gearing housing 54. It is advantageously possible for damping of vibrations of the operator control element 26 during operation of the portable power tool 14 to be made possible.

(23) FIG. 7 shows a force diagram of an operator control element force of the operator control element 26 in relation to a spring force of the clamping spring element 102 during a movement of the operator control element 26 around the movement axis 36 of the operator control element 26. The force diagram is depicted as a force-travel (angle) diagram in which a force is plotted versus a travel. An upper graph 88 of the force diagram shows a profile of an operator control element force of the operator control element 26 during a movement from the rest position (FIGS. 2 and 5) into the end position (FIG. 4). A middle graph 90 shows a profile of an operator control element force of the operator control element 26 during a movement from the end position (FIG. 4) into the rest position (FIGS. 2 and 5). A lower graph 92 shows a spring force profile of the clamping spring element 102 as a function of the movement of the operator control element 26.