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Machine Tool Device

20220297252 · 2022-09-22

    Inventors

    Cpc classification

    International classification

    Abstract

    A machine tool device includes at least one motor-driven machining tool; at least one sensor unit, in particular a capacitive sensor unit, which is configured to detect at least one foreign body in at least one detection area around the machining tool; and at least one open-loop and/or closed-loop control unit configured to trigger at least one action in accordance with at least one signal from the sensor unit. The sensor unit includes at least one antenna configured to emit at least one electric and/or magnetic field defining the at least one detection area and/or to detect the at least one foreign body in accordance with at least one change in at least one electric and/or magnetic field.

    Claims

    1. A power tool device comprising: at least one motor-drivable machining tool; at least one sensor unit configured to sense at least one foreign body in at least one detection area around the at least one machining tool; and at least one open-loop and/or closed-loop control unit configured to trigger at least one action based on at least one signal from the at least one sensor unit, wherein the at least one sensor unit comprises at least one antenna configured (i) to emit at least one electric and/or magnetic field defining the at least one detection area, and/or (ii) to sense the at least one foreign body based on at least one change in the at least one electric and/or magnetic field.

    2. The power tool device as claimed in claim 1, wherein the at least one sensor unit further comprises at least one field shielding element formed integrally with the at least one antenna and configured to shield the at least one electric and/or magnetic field emitted by the at least one antenna in at least one emission direction.

    3. The power tool device as claimed in claim 1, wherein the at least one sensor unit further comprises at least one electrical or electronic shielding circuit configured to shield the at least one electric and/or magnetic field emitted by the at least one antenna in at least one emission direction.

    4. The power tool device as claimed in claim 1, wherein the at least one open-loop and/or closed-loop control unit is configured to determine at least one movement characteristic of the at least one foreign body and/or at least one distance of the at least one foreign body from the at least one machining tool based on the at least one signal from the at least one sensor unit.

    5. The power tool device as claimed in claim 1, wherein the at least one open-loop and/or closed-loop control unit is configured to trigger different actions based on different determined movement characteristics of the at least one foreign body and/or based on different determined distances of the at least one foreign body from the at least one machining tool.

    6. The power tool device as claimed in claim 4, wherein the at least one open-loop and/or closed-loop control unit is configured to determine a probability of contact of the at least one foreign body with the moving at least one machining tool based on the at least one movement characteristic of the at least one foreign body and/or of the at least one distance of the at least one foreign body from the at least one machining tool and based on a minimum time for braking the at least one machining tool to a standstill.

    7. The power tool device as claimed in claim 6, wherein the at least one open-loop and/or closed-loop control unit is configured to trigger a different action based on the probability of contact being below a probability threshold value than based on the probability of contact being above the probability threshold value.

    8. The power tool device as claimed in claim 1, wherein the at least one open-loop and/or closed-loop control unit is configured to classify the at least one foreign body sensed by the at least one sensor unit and to trigger different actions based on different classifications.

    9. The power tool device as claimed in claim 1, wherein: the at least one open-loop and/or closed-loop control unit is configured to trigger the at least one action based on at least one parameter, and the at least one parameter includes at least one dimension of the at least one machining tool.

    10. The power tool device as claimed in claim 1, further comprising: at least one further sensor unit having at least one contact sensor element arranged in a vicinity, in a form of a guide region, of the at least one machining tool, the at least one further sensor unit configured to sense at least one body part of a user of the power tool device.

    11. The power tool device as claimed in claim 10, wherein the at least one open-loop and/or closed-loop control unit is configured to adapt at least one parameter, at least partially autonomously based on at least one signal from the at least one further sensor unit.

    12. The power tool device as claimed in claim 1, wherein the at least one antenna is configured as a ring about a longitudinal axis of the at least one machining tool.

    13. The power tool device as claimed in claim 1, wherein the at least one antenna is arranged parallel to a longitudinal axis of the at least one machining tool.

    14. The power tool device as claimed in claim 1, wherein: the at least one antenna is integrated in at least one mechanical protective element in a vicinity of the at least one machining tool, and/or the at least one antenna is configured to replace the at least one mechanical protective element.

    15. The power tool device as claimed in claim 1, further comprising: at least one housing from which the at least one sensor unit is configured to be uncoupled, wherein the at least one sensor unit has at least one wireless communications unit configured to provide the at least one signal to the at least one open-loop and/or closed-loop control unit.

    16. The power tool device as claimed in claim 1, further comprising: at least one dispensing unit configured to dispense the at least one machining tool, wherein the at least one open-loop and/or closed-loop control unit is configured to control the at least one dispensing unit to prevent or to enable the dispensing of the at least one machining tool based on the at least one signal from the at least one sensor unit.

    17. The power tool device as claimed in claim 1, further comprising: at least one mechanical brake unit configured (i) for control by the at least one open-loop and/or closed-loop control unit, and (ii) to brake the at least one machining tool, the at least one mechanical brake unit including a worm gear.

    18. The power tool device as claimed in claim 1, further comprising: at least one protective unit including at least one shielding element, wherein the at least one open-loop and/or closed-loop control unit is configured to control the at least one protective unit to move the at least one shielding element around the at least one machining tool based on the at least one signal from the at least one sensor unit.

    19. The power tool device as claimed in claim 1, further comprising: at least one retraction unit, wherein the open-loop and/or closed-loop control unit is configured to control the at least one retraction unit to move the at least one machining tool out of a machining area based on the at least one signal from the at least one sensor unit.

    20. A method for operating the power tool device as claimed in claim 1, comprising: emitting the at least one electric and/or magnetic field with the at least one antenna, the at least one electric and/or magnetic field defining the at least one detection area about the at least one machining tool of the power tool device; and/or sensing, using the at least one antenna, the at least one foreign body is sensed based on the at least one change in the at least one electric and/or magnetic field.

    21. (canceled)

    Description

    DRAWINGS

    [0048] Further advantages will become apparent from the following description of the drawings. In the drawings, ten exemplary embodiments of the invention are illustrated. The drawings, 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 useful further combinations.

    [0049] In the drawings:

    [0050] FIG. 1 shows a schematic perspective illustration of a power tool according to the invention,

    [0051] FIG. 2a shows the power tool according to the invention from FIG. 1 in a schematic illustration,

    [0052] FIG. 2b shows the power tool according to the invention from FIG. 1 with an alternative sensor unit in a schematic illustration,

    [0053] FIG. 2c shows the power tool according to the invention from FIG. 1 with a further alternative sensor unit in a schematic illustration,

    [0054] FIG. 3 shows a sectional view of a part of the power tool according to the invention in a schematic illustration,

    [0055] FIG. 4 shows a first alternative power tool according to the invention in a schematic perspective illustration,

    [0056] FIG. 5 shows a circuit arrangement of a part of a sensor unit of a power tool device according to the invention of the first alternative power tool according to the invention,

    [0057] FIG. 6 shows a second alternative power tool according to the invention in a schematic perspective illustration,

    [0058] FIG. 7 shows a third alternative power tool according to the invention in a schematic perspective illustration,

    [0059] FIG. 8 shows a fourth alternative power tool according to the invention in a schematic perspective illustration,

    [0060] FIG. 9 shows a fifth alternative power tool according to the invention in a schematic perspective illustration,

    [0061] FIG. 10 shows a sixth alternative power tool according to the invention in a schematic perspective illustration,

    [0062] FIG. 11 shows a seventh alternative power tool according to the invention in a schematic perspective illustration,

    [0063] FIG. 12 shows an eighth alternative power tool according to the invention in a schematic perspective illustration, and

    [0064] FIG. 13 shows a ninth alternative power tool according to the invention in a schematic perspective illustration.

    DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

    [0065] FIG. 1 shows a power tool 72a in a schematic perspective illustration. The power tool 72a comprises preferably at least one power tool device 10a. Preferably, the power tool device 10a comprises at least one motor-drivable machining tool 12a, at least one, in particular capacitive, sensor unit 14a, which is configured to sense at least one foreign body 16a, 18a in at least one detection area 20a around the machining tool 12a, and at least one open-loop and/or closed-loop control unit 22a, which is configured to trigger at least one action on the basis of at least one signal from the sensor unit 14a. Preferably, the power tool device 10a is in the form of a hand-held power tool device. In particular, the power tool 72a that comprises the power tool device 10a is in the form of a hand-held power tool. In particular, the power tool 72a is in the form of an electric power tool. In particular, the machining tool 12a is able to be driven by at least one electric motor of the power tool device 10a. Preferably, the power tool device 10a comprises at least one electrical energy storage unit 74a, in particular a rechargeable battery, for supplying energy at least to the electric motor. Alternatively, it is conceivable for the power tool device 10a to be in the form of a pneumatically powered power tool device, of a gasoline-powered power tool device or the like. Preferably, the power tool device 10a is intended for milling a workpiece 76a. In particular, the power tool 72a is in the form of a milling machine, in particular a trimmer. Alternatively, it is conceivable for the power tool 72a to be in the form of a plunge cut saw, of a tacker, of a tenon saw, of a foam saw, of a drywall cutter, of a plate jointer, of a belt grinder or sander, of a rotary tool, of a multi-cutter, of an, in particular autonomous, lawnmower, of a drilling machine, of an impact hammer, of a drywall screwdriver, of a heat gun, of a brushcutter, of a chopper, or of some other power tool that appears to make sense to a person skilled in the art. In particular, the machining tool 12a is in the form of a milling tool.

    [0066] Preferably, the sensor unit 14a comprises at least one antenna 24a, which is configured to emit at least one electric and/or magnetic field that defines the at least one detection area 20a, and/or to sense the at least one foreign body 16a, 18a on the basis of at least one change in at least one electric and/or magnetic field. The sensor unit 14a is preferably in the form of an electric, in particular capacitive, sensor unit. In particular, the sensor unit 14a is configured differently than an optical, acoustic, haptic or similar sensor unit. In particular, the sensor unit 14a is configured for proximity detection. Preferably, the sensor unit 14a is configured to sense the at least one foreign body 16a, 18a prior to contact with the machining tool 12a. In FIG. 1, by way of example, two foreign bodies 16a, 18a are illustrated, which are able to be sensed by the sensor unit 14a. In particular, the sensor unit 14a is configured to sense the foreign bodies 16a, 18a at at least a particular distance 32a, 34a, 36a from the machining tool 12a, in particular within the detection area 20a around the machining tool 12a. The detection area 20a is in particular an area which extends around the machining tool 12a and in which the sensor unit 14a is able and set up to detect the foreign bodies 16a, 18a. Preferably, the detection area 20a extends asymmetrically around the machining tool 12a. Preferably, the detection area 20a has a greater extent around points of the machining tool 12a that represent a risk to a user 48a of the power tool device 10a, in particular along a cutting edge of the machining tool 12a, than at other points of the machining tool 12a. Alternatively, it is conceivable for the detection area 20a to extend symmetrically, in particular spherically, around the machining tool 12a.

    [0067] The foreign bodies 16a, 18a may in particular be in the form of living objects, in particular of body parts 46a of the user 48a, for example a hand 78a, a finger, a leg or the like, of an animal or of some other living object that appears to make sense to a person skilled in the art. The foreign bodies 16a, 18a can in particular be in the form of inanimate objects, in particular of disruptive objects arranged on the workpiece 76a and/or extending in the vicinity of the workpiece 76a, for example of a nail 80a, of a power line, of a water pipe or the like. In the present exemplary embodiment, a foreign body 16a is in the form for example of a living object, in particular of a hand 78a of the user 48a, and a further foreign body 18a is in the form for example of an inanimate object, in particular of a nail 80 arranged on the workpiece 76a.

    [0068] Preferably, the open-loop and/or closed-loop control unit 22a is connected to the sensor unit 14a for signal transmission purposes, in particular via at least one signal line (not illustrated here). Alternatively or additionally, it is conceivable for the open-loop and/or closed-loop control unit 22a to be connected to the sensor unit 14a for signal transmission purposes via a wireless signal connection. Preferably, the open-loop and/or closed-loop control unit 22a is configured to control the sensor unit 14a. The sensor unit 14a is in particular configured to provide the at least one signal, preferably a plurality of signals, to the open-loop and/or closed-loop control unit 22a, in particular on the basis of at least one of the foreign bodies 16a, 18a being sensed in the detection area 20a. Preferably, the open-loop and/or closed-loop control unit 22a is configured to evaluate the at least one signal received from the sensor unit 14a. In particular, the open-loop and/or closed-loop control unit 22a is configured to trigger the at least one action on the basis of an evaluation of the at least one signal from the sensor unit 14a.

    [0069] The at least one action is preferably in the form of a safety function, in particular for preventing or at least for minimizing injury to the user 48a, and/or of a comfort function, in particular for making it easier for the user 48a to operate the power tool device 10a. The at least one action can in particular be in the form of braking of the machining tool 12a, of moving the machining tool 12a out of a risk area 82a, of shielding the machining tool 12a, of outputting at least one, in particular visual, audible and/or haptic, warning, of making an emergency call, or of some other action that appears to make sense to a person skilled in the art. In particular, the open-loop and/or closed-loop control unit 22a can be configured to trigger a plurality of, in particular different, actions. Preferably, the open-loop and/or closed-loop control unit 22a can be configured to trigger different actions on the basis of different signals from the sensor unit 14a. In particular, the open-loop and/or closed-loop control unit 22a is configured, on the basis of the at least one signal from the sensor unit 14a, in particular for triggering the at least one action, to control at least one reaction unit 84a, 86a, 88a of the power tool device 10a which is intended to carry out the at least one action. The at least one reaction unit 84a, 86a, 88a can in particular be in the form of a brake unit 60a, of a protective unit 64a, in particular of a covering unit, of a pivoting unit, of a blocking unit, of a signal output unit, of a communications unit, of a retraction unit 68a or of some other unit that appears to make sense to a person skilled in the art. In the present exemplary embodiment, the power tool device 10a comprises for example three reaction units 84a, 86a, 88a, wherein a first reaction unit 84a is in the form of a mechanical brake unit 60a, a second reaction unit 86a is in the form of a protective unit 64a and a third reaction unit 88a is in the form of a retraction unit 68a. The mechanical brake unit 60a is intended in particular to block an output shaft 90a of the power tool device 10a on which the machining tool 12a is mounted, in particular to block rotation of the output shaft 90a.

    [0070] The at least one antenna 24a is preferably configured to conduct electric power. In particular, the at least one antenna 24a is formed in a cylindrical, in particular circular cylindrical, manner. In particular, the at least one antenna 24a is configured to emit an electric field that is distributed radially symmetrically about a longitudinal axis of the antenna 24a, and/or to emit a magnetic field that is distributed concentrically about the longitudinal axis of the antenna 24a. Preferably, the at least one antenna 24a is in the form of a cable, in particular of a coaxial cable, of a wire or the like. It is also conceivable for the antenna 24a to be formed from a plurality of electrodes. Alternatively or additionally, it is conceivable for the machining tool 12a and/or the output shaft 90a on which the machining tool 12a is mounted to form the at least one antenna 24a, and/or for the at least one antenna 24a to be configured to be electrically coupled to the machining tool 12a and/or to the output shaft 90a. Preferably, the machining tool 12a is in the form of the at least one antenna, wherein the sensor unit 14a has at least one further antenna 24a, which is formed separately from the machining tool 12a. In the present exemplary embodiment, the sensor unit 14a has for example the antenna 24a, which is formed separately from the machining tool 12a, in particular in the form of a coaxial cable. Alternatively or additionally, it is conceivable for the at least one antenna 24a to be formed separately from the power tool device 10a, in particular to be arranged on the user 48a, for example on a glove or on protective goggles of the user 48a.

    [0071] In particular, the at least one antenna 24a is configured to emit at least one electromagnetic field. In particular, the electric and/or magnetic, in particular electromagnetic, field of the at least one antenna 24a, in particular a field strength and/or a maximum extent of the electric and/or magnetic field of the at least one antenna 24a, is dependent on an electric voltage applied to the at least one antenna 24a and/or on an electric current flowing through the at least one antenna 24a. In particular, the detection area 20a has at least substantially an identical shape to the electric and/or magnetic, in particular electromagnetic, field of the at least one antenna 24a. In particular, a boundary of the detection area 20a is defined by a sum of all the distances around the at least one antenna 24a which have an identical minimum, in particular predefined, field strength of the electric and/or magnetic field of the at least one antenna 24a. Preferably, the at least one antenna 24a is arranged in the vicinity 42a of the machining tool 12a. In particular, the sensor unit 14a can have a plurality of antennas 24a, in particular to realize full coverage of the machining tool 12a with a detection area 20a. In particular, the sensor unit 14a can have at least two antennas 24a, preferably at least four antennas 24a, particularly preferably at least six antennas 24a, and very particularly preferably at least 8 antennas 24a. In the present exemplary embodiment, the sensor unit 14a has for example the single antenna 24a.

    [0072] Preferably, the at least one antenna 24a is configured to sense the foreign bodies 16a, 18a on the basis of a change in the electric and/or magnetic field emitted by the at least one antenna 24a. Alternatively or additionally, it is conceivable for the at least one antenna 24a to be configured to sense the foreign bodies 16a, 18a on the basis of a change in a further electric and/or magnetic field, in particular one emitted by another antenna. In particular, the sensor unit 14a can comprise at least two antennas 24a, wherein a first antenna 24a is configured to emit an electric and/or magnetic field and wherein a second antenna is configured to sense the foreign bodies 16a, 18a on the basis of a change in the electric and/or magnetic field of the first antenna 24a. In particular, the foreign bodies 16a, 18a arranged in the detection area 20a change the electric and/or magnetic field, in particular characteristics of the electric and/or magnetic field, in particular on the basis of electrical and/or magnetic properties of the foreign bodies 16a, 18a. Preferably, the at least one antenna 24a is configured to sense the foreign bodies 16a, 18a capacitively, in particular on the basis of a change in capacitance, brought about by the foreign bodies 16a, 18a, of the electric and/or magnetic field. Alternatively or additionally, it is conceivable for the at least one antenna 24a to be configured to sense the foreign bodies 16a, 18a inductively, in particular on the basis of a change in inductance, brought about by the foreign bodies 16a, 18a, of the electric and/or magnetic field.

    [0073] Preferably, the sensor unit 14a comprises at least one tuning circuit that is connected to the antenna 24a (not illustrated here; cf. 158b in FIG. 5). The tuning circuit is intended in particular at least to generate an electric and/or magnetic field through interaction with the antenna 24a. The tuning circuit is preferably formed at least from a resonant circuit, in particular an RLC resonant circuit, and from a phase stabilization circuit. Preferably, an operating frequency of the tuning circuit is less than 5 MHz. Alternatively, it is also conceivable, however, for the operating frequency of the tuning circuit to be greater than 5 MHz. The tuning circuit has in particular at least one amplifier, which is formed for example by a field effect transistor, a bipolar transistor, an operational amplifier or the like. Furthermore, various amplifier topologies are conceivable, for example a telescopic topology, a two-stage amplifier topology, a cascode topology or the like. The tuning circuit is preferably connected to a signal processing unit, in particular an analog-digital converter, wherein the signal processing unit is connectable, for signal transmission, at least to the open-loop and/or closed-loop control unit 22a. The signal processing unit comprises preferably at least one comparator, in particular a Schmitt trigger, which is usable for converting an analog signal, preferably from the antenna 24a, into a digital signal.

    [0074] Preferably, the open-loop and/or closed-loop control unit 22a is configured to determine at least one movement characteristic of the at least one foreign body 16a, 18a and/or at least one distance 32a, 34a, 36a of the at least one foreign body 16a, 18a from the machining tool 12a on the basis of the at least one signal from the sensor unit 14a. Preferably, the open-loop and/or closed-loop control unit 22a is configured to trigger the at least one action on the basis of the at least one determined movement characteristic of the foreign bodies 16a, 18a and/or on the basis of the at least one determined distance 32a, 34a, 36a of the foreign bodies 16a, 18a from the machining tool 12a. In particular, the open-loop and/or closed-loop control unit 22a is configured to evaluate the at least one determined movement characteristic of the foreign bodies 16a, 18a and/or the at least one determined distance 32a, 34a, 36a of the foreign bodies 16a, 18a from the machining tool 12a and to trigger the at least one action in particular on the basis of a result of the evaluation. The at least one movement characteristic of the foreign bodies 16a, 18a is preferably in the form of a speed of movement of the foreign bodies 16a, 18a, in particular of a speed at which the foreign bodies 16a, 18a approach the machining tool 12a, of an acceleration of movement of the foreign bodies 16a, 18a, in particular of an acceleration with which the foreign bodies 16a, 18a approach the machining tool 12a, of a direction of movement of the foreign bodies 16a, 18a or of some other movement characteristic that appears to make sense to a person skilled in the art. In particular, the open-loop and/or closed-loop control unit 22a is configured to determine the distance 32a, 34a, 36a of the foreign bodies 16a, 18a from the machining tool 12a, in particular a position of the foreign bodies 16a, 18a at least relative to the machining tool 12a, on the basis of the at least one signal from the sensor unit 14a. Preferably, the open-loop and/or closed-loop control unit 22a is configured to determine the at least one movement characteristic of the foreign bodies 16a, 18a on the basis of a plurality of signals from the sensor unit 14a, in particular signals that are sensed with a time offset. In particular, the open-loop and/or closed-loop control unit 22a is configured to determine the speed of movement of the foreign bodies 16a, 18a, in particular the speed at which the foreign bodies 16a, 18a approach the machining tool 12a, on the basis of a period of time that has passed between two operations of sensing and/or determining the foreign bodies 16a, 18a at two different distances 32a, 34a, 36a from the machining tool 12a, in particular at two different positions, and on the basis of a spatial difference between the two different distances 32a, 34a, 36a from the machining tool 12a, in particular between the two different positions. Preferably, the open-loop and/or closed-loop control unit 22a is configured to determine the acceleration of the movement of the foreign bodies 16a, 18a, in particular the acceleration with which the foreign bodies 16a, 18a approach the machining tool 12a, on the basis of different determined speeds of movement of the foreign bodies 16a, 18a at different distances 32a, 34a, 36a from the machining tool 12a, in particular at different positions. In the present exemplary embodiment, the foreign body 16a in the form of a hand 78a of the user 48a is for example at a distance 32a from the machining tool 12a. FIG. 1 additionally illustrates a further distance 34a of the foreign body 16a from the machining tool 12a, which is in particular smaller than the distance 32a of the foreign body 16a from the machining tool 12a, in particular on account of an interim movement of the foreign body 16a in the direction of the machining tool 12a. In the present exemplary embodiment, the further foreign body 18a in the form of a nail 80a is for example at a distance 36a from the machining tool 12a.

    [0075] Preferably, the open-loop and/or closed-loop control unit 22a is configured to determine the distance 32a, 34a, 36a of the foreign bodies 16a, 18a from the machining tool 12a, in particular the position of the foreign bodies 16a, 18a at least relative to the machining tool 12a, on the basis of a signal strength of the signal sensed by the sensor unit 14a, in particular on the basis of a level in the change of the electric and/or magnetic field of the at least one antenna 24a. Alternatively or additionally, it is conceivable for the sensor unit 14a to be configured to provide a plurality of detection areas 20a with different radii around the machining tool 12a, wherein the open-loop and/or closed-loop control unit 22a is configured in particular to determine the distance 32a, 34a, 36a of the foreign bodies 16a, 18a from the machining tool 12a, in particular the position of the foreign bodies 16a, 18a, on the basis of the foreign bodies 16a, 18a being sensed in a particular detection area 20a (this not being illustrated in further detail here). Preferably, the at least one antenna 24a is configured to provide the plurality of detection areas 20a with different radii around the machining tool 12a. Alternatively or additionally, it is conceivable for the sensor unit 14a to comprise a plurality of antennas 24a, in particular a number of antennas 24a corresponding to a number of detection areas 20a to be provided, wherein in particular in each case one antenna 24a is configured to provide at least one of the plurality of detection areas 20a. Preferably, the detection areas 20a may be in the form of layers or shells, in particular cylindrical shells, spherical shells or the like. In particular, the detection areas 20a may have equidistant extents between one another as seen along the radii of the detection areas 20a. Alternatively, it is conceivable for the detection areas 20a to have different extents between one another as seen along the radii of the detection areas 20a.

    [0076] Preferably, the open-loop and/or closed-loop control unit 22a is configured to trigger different actions on the basis of different determined movement characteristics of the at least one foreign body 16a, 18a and/or on the basis of different determined distances 32a, 34a, 36a of the at least one foreign body 16a, 18a from the machining tool 12a. In particular, a plurality of different movement characteristics of the foreign bodies 16a, 18a and/or of different distances 32a, 34a, 36a of the foreign bodies 16a, 18a from the machining tool 12a and a plurality of actions to be triggered that are associated with the different movement characteristics and/or the different distances 32a, 34a, 36a of the foreign bodies 16a, 18a can be stored in a memory unit of the open-loop and/or closed-loop control unit 22a. Preferably, the open-loop and/or closed-loop control unit 22a is configured to compare the determined movement characteristic of the foreign bodies 16a, 18a and/or the determined distance 32a, 34a, 36a of the foreign bodies 16a, 18a with the movement characteristics and/or distances 32a, 34a, 36a of the foreign bodies 16a, 18a that are stored in the memory unit. In particular, the open-loop and/or closed-loop control unit 22a is configured to trigger the at least one action associated with the determined movement characteristic and/or the determined distance 32a, 34a, 36a of the foreign bodies 16a, 18a on the basis of the comparison.

    [0077] For example, it is conceivable for the open-loop and/or closed-loop control unit 22a to be configured to trigger an output of a warning signal on the basis of a determined first speed of movement of the foreign bodies 16a, 18a and/or on the basis of a determined first distance 32a of the foreign bodies 16a, 18a from the machining tool 12a. For example, it is conceivable for the open-loop and/or closed-loop control unit 22a to be configured to trigger a reduction in rotational speed of a motor 92a driving the machining tool 12a on the basis of a determined second speed of movement of the foreign bodies 16a, 18a that is faster than the first speed of movement of the foreign bodies 16a, 18a and/or on the basis of a determined second distance 34a of the foreign bodies 16a, 18a from the machining tool 12a that is less than the determined first distance 32a of the foreign bodies 16a, 18a from the machining tool 12a. For example, it is conceivable for the open-loop and/or closed-loop control unit 22a to be configured to trigger braking of the motor 92a driving the machining tool 12a and/or of the machining tool 12a on the basis of a determined third speed of movement of the foreign bodies 16a, 18a that is faster than the second speed of movement of the foreign bodies 16a, 18a and/or on the basis of a determined third distance 36a of the foreign bodies 16a, 18a from the machining tool 12a that is less than the determined second distance 34a of the foreign bodies 16a, 18a from the machining tool 12a.

    [0078] Preferably, the open-loop and/or closed-loop control unit 22a is configured to determine a probability of contact of the at least one foreign body 16a, 18a with the moving machining tool 12a on the basis of the at least one movement characteristic of the at least one foreign body 16a, 18a and/or of the at least one distance 32a, 34a, 36a of the at least one foreign body 16a, 18a from the machining tool 12a and on the basis of a minimum time for braking the machining tool 12a to a standstill. In particular, the open-loop and/or closed-loop control unit 22a is configured to evaluate the at least one movement characteristic of the foreign bodies 16a, 18a and/or the at least one distance 32a, 34a, 36a of the foreign bodies 16a, 18a from the machining tool 12a and the minimum time for braking the machining tool 12a to a standstill in order to determine the probability of contact of the foreign bodies 16a, 18a with the moving machining tool 12a.

    [0079] In particular, the open-loop and/or closed-loop control unit 22a is configured to determine the minimum time for braking the machining tool 12a to a standstill, in particular on the basis of characteristics of the machining tool 12a, for example an inertia of the machining tool 12a, a rotational speed of the machining tool 12a, a speed of movement of the machining tool 12a or the like, and on the basis of available braking possibilities for braking the machining tool 12a to a standstill, for example a maximum braking force of the brake unit 60a of the power tool device 10a, a minimum activation duration of the brake unit 60a, a minimum time until engagement of the brake unit 60a or the like. In particular, the power tool device 10a can have at least one sensing unit 94a which is configured to sense the characteristics of the machining tool 12a and the available braking possibilities and to provide them to the open-loop and/or closed-loop control unit 22a. Alternatively or additionally, it is conceivable for the maximum time for braking the machining tool 12a to a standstill and/or at least the characteristics of the machining tool 12a and/or the available braking possibilities to be stored in the memory unit of the open-loop and/or closed-loop control unit 22a. Preferably, the open-loop and/or closed-loop control unit 22a is configured to trigger the at least one action on the basis of the determined probability of contact of the foreign bodies 16a, 18a with the moving machining tool 12a, in particular on the basis of an evaluation of the determined probability of contact of the foreign bodies 16a, 18a with the moving machining tool 12a.

    [0080] Preferably, the open-loop and/or closed-loop control unit 22a is configured to trigger a different action on the basis of the probability of contact being below a probability threshold value than on the basis of the probability of contact being above the probability threshold value. The probability threshold value is preferably stored in the memory unit of the open-loop and/or closed-loop control unit 22a. In particular, the probability threshold value is in the form of a value of a probability of contact of the foreign bodies 16a, 18a with the moving machining tool 12a of between 0% and 100%, for example 10%. Preferably, the open-loop and/or closed-loop control unit 22a is configured to compare the determined probability of contact with the probability threshold value and to trigger the at least one action on the basis of the comparison. For example, it is conceivable for the open-loop and/or closed-loop control unit 22a to be configured to trigger braking of the machining tool 12a on the basis of the probability of contact being below the probability threshold value and to additionally trigger the making of an emergency call on the basis of the probability of contact being above the probability threshold value.

    [0081] Preferably, the open-loop and/or closed-loop control unit 22a is configured to classify different foreign bodies 16a, 18a sensed by the sensor unit 14a and to trigger different actions on the basis of different classifications. In particular, the open-loop and/or closed-loop control unit 22a is configured to distinguish between different types of foreign bodies 16a, 18a on the basis of different signals from the sensor unit 14a, in the present exemplary embodiment for example between the foreign body 16a and the further foreign body 18a. In particular, different types of foreign bodies 16a, 18a have different electrical and/or magnetic, in particular capacitive, properties, and in particular influence the electric and/or magnetic field of the antenna 24a differently. In particular, each type of foreign body 16a, 18a has its own electrical and/or magnetic, in particular capacitive, signature. Preferably, the open-loop and/or closed-loop control unit 22a is configured to identify a type of the foreign body 16a, 18a on the basis of the electrical, in particular capacitive, signature of the foreign body 16a, 18a and to classify the foreign body 16a, 18a. Preferably, electrical and/or magnetic, in particular capacitive, signatures of different types of foreign bodies 16a, 18a are stored in the memory unit of the open-loop and/or closed-loop control unit 22a. In particular, the open-loop and/or closed-loop control unit 22a is configured to compare a signal from the sensor unit 14a corresponding to sensing of a foreign body 16a, 18a with the stored signatures and to classify the foreign body 16a, 18a on the basis of the comparison.

    [0082] In particular, the open-loop and/or closed-loop control unit 22a is configured to distinguish between living and inanimate foreign bodies 16a, 18a on the basis of different signals from the sensor unit 14a and to accordingly classify the foreign bodies 16a, 18a. Preferably, the open-loop and/or closed-loop control unit 22a is configured to distinguish between human and animal living foreign bodies 16a on the basis of different signals from the sensor unit 14a and to accordingly classify the foreign bodies 16a. In the present exemplary embodiment, the open-loop and/or closed-loop control unit 22a is configured for example to classify the hand 78a of the user 48a as the human living foreign body 16a. Preferably, the open-loop and/or closed-loop control unit 22a is configured to distinguish between inanimate foreign bodies 18a of different material on the basis of different signals from the sensor unit 14a and to accordingly classify the foreign bodies 18a. In the present exemplary embodiment, the open-loop and/or closed-loop control unit 22a is configured for example to classify the nail 80a as the inanimate foreign body 18a made of a metal. Preferably, different actions to be triggered that are associated with the different classifications of foreign bodies 16a, 18a are stored in the memory unit of the open-loop and/or closed-loop control unit 22a. In particular, the open-loop and/or closed-loop control unit 22a is configured to trigger at least one action associated with a classification of a sensed foreign body 16a, 18a. For example, it is conceivable for the open-loop and/or closed-loop control unit 22a to be configured to trigger pivoting of the machining tool 12a away from the risk area 82a on the basis of the sensed further foreign body 18a being classified as an inanimate foreign body 18a and to trigger mechanical braking of the machining tool 12a on the basis of the sensed foreign body 16a being classified as a living foreign body 16a.

    [0083] Preferably, the power tool device 10a comprises at least one further sensor unit 40a which has at least one contact sensor element 44a, arranged in the vicinity 42a, in particular in the abovementioned vicinity 42a, in the form of a guide region, of the machining tool 12a, for sensing at least one body part 46a of a user 48a, in particular of the abovementioned user 48a. Preferably, a power tool 72a in the form of a milling machine, in particular of a router, of a saw, in particular of a chain saw, or of a hedge trimmer, for example in the form of a trimmer in the present exemplary embodiment, comprises the power tool device 10a that has the at least one guide region. Preferably, the guide region is formed at least partially by a base unit 96a of the power tool device 10a, in particular by a guide element 98a of the base unit 96a, for example a sliding shoe, as in the present exemplary embodiment for example, or a handle. Preferably, the machining tool 12a, in particular the output shaft 90a, extends at least partially through the guide element 98a, formed in particular as a sliding shoe. In particular, the power tool device 10a is guidable along the workpiece 76a by means of the guide element 98a. In particular, the guide element 98a, formed in particular as a sliding shoe, is intended to bear on the workpiece 76a. Preferably, the guide element 98a is intended to be grasped, in particular in the guide region, by the user 48a, in particular to effect controlled guidance of the power tool device 10a. Preferably, the at least one contact sensor element 44a is arranged on the guide element 98a, in particular integrated in the guide element 98a with a precise fit. In the present exemplary embodiment, the further sensor unit 40a has for example two contact sensor elements 44a, which are arranged in particular on sides of the guide element 98a that face away from one another. In particular, the contact sensor elements 44a are arranged in recessed grips 100a of the guide element 98a.

    [0084] Preferably, the contact sensor elements 44a are in the form of capacitive sensors, as for example in the present exemplary embodiment, of pressure-sensitive sensors, of fingerprint scanners, of conductivity sensors, or of other contact sensor elements that appear to make sense to a person skilled in the art. Preferably, the further sensor unit 40a is connected to the open-loop and/or closed-loop control unit 22a for signal transmission purposes, in particular via a signal line and/or a wireless connection (not illustrated here). In particular, the further sensor unit 40a is configured to provide at least one signal to the open-loop and/or closed-loop control unit 22a on the basis of sensing of the at least one body part 46a, in particular at least one finger, of the user 48a. Preferably, the open-loop and/or closed-loop control unit 22a is configured to trigger the at least one action on the basis of the at least one signal from the further sensor unit 40a, in particular on the basis of sensing of the at least one body part 46a in the guide region. For example, it is conceivable for the open-loop and/or closed-loop control unit 22a to be designed to activate the motor 92a that drives the machining tool 12a on the basis of sensing of the body part 46a. For example, it is conceivable for the open-loop and/or closed-loop control unit 22a to be configured to deactivate the motor 92a that drives the machining tool 12a on the basis of a lack of sensing of the body part 46a, in particular to prevent uncontrolled guidance of the power tool device 10a.

    [0085] Preferably, the open-loop and/or closed-loop control unit 22a is configured to adapt at least one parameter, in particular the at least one detection area 20a, at least partially autonomously on the basis of at least one signal from the further sensor unit 40a. Preferably, the open-loop and/or closed-loop control unit 22a is configured to adapt the at least one parameter entirely autonomously, in particular automatically, on the basis of the at least one signal from the further sensor unit 40a. Alternatively, it is conceivable for the open-loop and/or closed-loop control unit 22a to be configured to adapt the at least one parameter partially autonomously. In particular, the open-loop and/or closed-loop control unit 22a can be configured to provide the user 48a, on the basis of the at least one signal from the further sensor unit 40a, in particular on the basis of the evaluation of the at least one signal from the further sensor unit 40a, with at least one recommendation for adaptation of the at least one parameter, for example via a signal output unit of the power tool device 10a, and to adapt the at least one parameter on the basis of a user input. In particular, the open-loop and/or closed-loop control unit 22a can be configured to adapt a plurality of parameters at least partially autonomously on the basis of the at least one signal from the further sensor unit 40a. The at least one parameter to be adapted can in particular be in the form of a sensitivity of the sensor unit 14a, of the detection area 20a, in particular of the extent of the detection area 20a, of the shape of the detection area 20a or the like, of a type of the at least one action to be triggered, of a sequence of a number of actions to be triggered, of a triggering speed and/or of a speed at which the at least one action is carried out, for example a braking speed of the machining tool 12a, or of some other parameter that appears to make sense to a person skilled in the art.

    [0086] Preferably, the open-loop and/or closed-loop control unit 22a is configured to adapt the detection area 20a, in particular the extent of the detection area 20a, in particular to make it larger or smaller, at least partially autonomously on the basis of the at least one signal from the further sensor unit 40a. In particular, the open-loop and/or closed-loop control unit 22a is configured, on the basis of a signal from the further sensor unit 40a corresponding to sensing of the at least one body part 46a in the guide region, to at least partially autonomously set the detection area 20a, in particular a maximum extent of the detection area 20a, to be smaller than a minimum distance between the machining tool 12a and the guide region, in particular to avoid erroneous triggering by the body part 46a. In particular, the open-loop and/or closed-loop control unit 22a is configured, on the basis of a signal from the further sensor unit 40a corresponding to a lack of sensing of the at least one body part 46a in the guide region, to at least partially autonomously set the detection area 20a, in particular a maximum extent of the detection area 20a, to be larger than a minimum distance between the machining tool 12a and the guide region, in particular to reduce a risk of injury as a result of incorrect operation of the power tool device 10a.

    [0087] Preferably, the power tool device 10a comprises at least one protective unit 64a, in particular the abovementioned protective unit 64a, which has at least one shielding element 66a, wherein the open-loop and/or closed-loop control unit 22a is configured to control the protective unit 64a to move the at least one shielding element 66a around the machining tool 12a on the basis of the at least one signal from the sensor unit 14a. In particular, the power tool device 10a has the protective unit 64a as an alternative or, as for example in the present exemplary embodiment, in addition to the mechanical brake unit 60a. Preferably, the shielding element 66a is intended to at least partially cover, in particular to enclose, the machining tool 12a. In FIG. 1, the protective unit 64a is illustrated for example in an activated state, in which the shielding element 66a at least partially covers the machining tool 12a. In particular, the shielding element 66a is intended to cover, in particular to enclose, at least one risk area 102a, in particular at least one milling edge, of the machining tool 12a. Preferably, the shielding element 66a is intended to protect the foreign body 16a, in particular the body part 46a of the user 48a, from the machining tool 12a and/or the machining tool 12a from the further foreign body 18a. In particular, the shielding element 66a is intended to prevent the machining tool 12a from being grasped, in particular by the user 48a. The shielding element 66a can in particular be in the form of a shielding hood, as for example in the present exemplary embodiment, of a shielding cover, of an airbag, of a cage or of some other shielding element that appears to make sense to a person skilled in the art. In particular, the shielding element 66a is mounted movably on, in particular at least partially within, the base unit 96a of the power tool device 10a, in particular of a housing 54a of the base unit 96a. In particular, the shielding element 66a can be formed in a telescopic, as for example in the present exemplary embodiment, inflatable, clampable or similar manner. Preferably, the protective unit 64a comprises at least one actuator 104a, which is intended to move the shielding element 66a around the machining tool 12a and/or to enable the shielding element 66a to be moved by at least one further actuator of the protective unit 64a. In particular, the open-loop and/or closed-loop control unit 22a is configured to control the actuator 104a to move the shielding element 66a around the machining tool 12a on the basis of the at least one signal from the sensor unit 14a. The at least one actuator 104a can in particular be in the form of an electromagnetic actuator, of a spring force actuator, of a compressed-air actuator, of an explosive actuator, of a fuse wire actuator, of a shape memory actuator or of some other actuator that appears to make sense to a person skilled in the art.

    [0088] Preferably, the power tool device 10a comprises at least one retraction unit 68a, wherein the open-loop and/or closed-loop control unit 22a is configured to control the retraction unit 68a to move the machining tool 12a out of a machining area 70a on the basis of the at least one signal from the sensor unit 14a. In particular, the power tool device 10a has the retraction unit 68a as an alternative or, as for example in the present exemplary embodiment, in addition to the mechanical brake unit 60a and/or to the protective unit 64a. The machining area 70a is in particular an area within the detection area 20a. In particular, the machining area 70a can correspond to the detection area 20a. In particular, at least the machining tool 12a and at least the workpiece 76a are arranged at least partially in the machining area 70a. In particular, in the machining area 70a, there is a risk of injury for the user 48a by touching the machining tool 12a and/or a risk of damage for the machining tool 12a by touching the foreign body 18a. In FIG. 1, the retraction unit 68a is illustrated for example in a deactivated state, in which the machining tool 12a is arranged in particular in the machining area 70a. The retraction unit 68a is preferably intended to pull, in particular to retract, as for example in the present exemplary embodiment, to push, to drive or pivot the machining tool 12a out of the machining area 70a or to move it out of the machining area 70a in some other way that appears to make sense to a person skilled in the art. Preferably, the retraction unit 68a is intended to move the machining tool 12a away from the sensed foreign bodies 16a, 18a. In particular, the retraction unit 68a is intended to move the machining tool 12a at least partially into an at least partially covered area of the power tool device 10a, for example into the base unit 96a, in particular into the housing 54a, into a protective hood or the like.

    [0089] Preferably, the retraction unit 68a comprises at least one actuator 106a, which is intended to move the machining tool 12a out of the machining area 70a. The actuator 106a is preferably operatively connected to the machining tool 12a, in particular directly, for example mechanically, magnetically or the like, and/or indirectly, for example via a pivot arm, the output shaft 90a, as for example in the present exemplary embodiment, or the like. Preferably, the machining tool 12a and/or at least one component on which the machining tool 12a is mounted, for example the output shaft 90a, as for example in the present exemplary embodiment, the pivot arm or the like, is/are mounted movably, in particular so as to be movable out of the machining area 70a. In particular, the open-loop and/or closed-loop control unit 22a is configured to control the actuator 106a to move the machining tool 12a out of the machining area 70a on the basis of the at least one signal from the sensor unit 14a. The at least one actuator 106a can in particular be in the form of an electromagnetic actuator, of a spring force actuator, of a compressed-air actuator, of an explosive actuator, of a fuse wire actuator, of a shape memory actuator or of some other actuator that appears to make sense to a person skilled in the art. In particular, the actuator 106a and/or the open-loop and/or closed-loop control unit 22a can be intended to use brake energy of braking of the machining tool 12a and/or at least one electric current from motor braking of the motor 92a driving the machining tool 12a to move the machining tool 12a. The actuator 106a can in particular be intended to uncouple the machining tool 12a and/or the output shaft 90a from the motor 92a driving the machining tool 12a in order to move the machining tool 12a out of the machining area 70a. In particular, the retraction unit 68a can have ramp elements along which the machining tool 12a and/or the output shaft 90a can slide out of the machining area 70a on the basis of motion energy, in particular rotational energy, of the machining tool 12a and/or of the output shaft 90a (this not being illustrated here). FIG. 2a shows the power tool 72a from FIG. 1, in particular an underside 108a of the guide element 98a, in a schematic illustration. The underside 108a of the guide element 98a is in particular in the form of a sliding face 110a of the power tool device 10a. Preferably, the at least one antenna 24a is arranged in the form of a ring about a longitudinal axis 50a of the machining tool 12a. Preferably, a power tool 72a in the form of a router, of a trimmer, of a jigsaw or of a reciprocating saw, in the present exemplary embodiment for example the power tool 72a in the form of a trimmer, comprises the power tool device 10a having the at least one antenna 24a that is arranged in the form of a ring about the longitudinal axis 50a of the machining tool 12a. Preferably, the at least one antenna 24a is arranged in a plane 112a, in particular in the sliding face 110a, which extends transversely, in particular perpendicularly, to the longitudinal axis 50a of the machining tool 12a. Preferably, the at least one antenna 24a is arranged in the form of a circular ring, of a partial ring, in particular of a half ring, or the like, about the longitudinal axis 50a of the machining tool 12a. In the present exemplary embodiment, the antenna 24a is arranged for example in the form of a circular ring, in particular locally interrupted. Preferably, the at least one antenna 24a is arranged on the base unit 96a of the power tool device 10a, in particular on the guide element 98a, in the form in particular of a sliding shoe. In particular, the at least one antenna 24a can be arranged at least partially within the base unit 96a, in particular within the guide element 98a. Preferably, the sensor unit 14a can have a plurality of antennas 24a, wherein in particular two antennas 24a can be arranged on sides of the guide element 98a that face away from one another. Preferably, the at least one antenna 24a is arranged in the at least one plane 112a that extends parallel to the sliding face 110a of the guide element 98a, in the form in particular of a sliding shoe. FIG. 2b shows the power tool 72a from FIG. 1, in particular an underside 108a of a guide element 98a, with an alternative sensor unit 14a′ in a schematic illustration. In particular, the sensor unit 14a′ comprises two antennas 24a′, 26a′, in particular a first antenna 24a′ and a second antenna 26a′. Preferably, the antennas 24a′, 26a′ are arranged in the form of a half ring about a longitudinal axis 50a of a machining tool 12a. In particular, the antennas 24a′, 26a′ are arranged so as not to be connected to one another. In particular, the antennas 24a′, 26a′ each form a circular ring segment, in particular of a locally interrupted circular ring.

    [0090] FIG. 2c shows the power tool 72a from FIG. 1, in particular an underside 108a of a guide element 98a, with a further alternative sensor unit 14a″ in a schematic illustration. In particular, the sensor unit 14a″ comprises four antennas 24a″, 26a″, 28a″, 30a″, in particular a first antenna 24a″, a second antenna 26a″, a third antenna 28a″ and a fourth antenna 30a″. Preferably, the antennas 24a″, 26a″, 28a″, 30a″ are arranged in the form of a quarter circular ring about a longitudinal axis 50a of a machining tool 12a. In particular, the antennas 24a″, 26a″, 28a″, 30a″ are arranged so as not to be connected to one another. In particular, the antennas 24a″, 26a″, 28a″, 30a″ each form a circular ring segment, in particular of a locally interrupted circular ring.

    [0091] FIG. 3 shows a sectional view of a part of the power tool 72a from FIG. 2a in a schematic illustration, in which at least the antenna 24a of the sensor unit 14a is depicted. Preferably, the sensor unit 14a comprises at least one field shielding element 148a which is formed in particular integrally with the antenna 24a and is configured to shield an electric and/or magnetic field, emitted by the antenna 24a, in at least one emission direction 150a. The field shielding element 148a is formed preferably from a material that is not transparent to electromagnetic radiation, preferably to electric and/or magnetic fields, in particular from a metal, for example from a lead, from an iron, from a steel or the like. It is also conceivable for the antenna 24a to be formed partially by a coaxial cable, wherein the coaxial cable forms the field shielding element 148a. In particular, the field shielding element 148a is intended to absorb and/or reflect the electric and/or magnetic field of the antenna 24a in the emission direction 150a. In addition, it is conceivable for the field shielding element 148a to be configured to focus the electric and/or magnetic field of the antenna 24a in at least one emission direction 152a without shielding. In particular, the antenna 24a is arranged without shielding as seen in at least one emission direction 152a. In particular, at least one risk area of the machining tool is arranged in the at least one emission direction 152a, as seen in which the at least one antenna 24a is arranged without shielding (this not being illustrated here).

    [0092] In the following text, a method for operating a power tool device, in particular the abovementioned power tool device 10a, is described, in particular with reference to FIG. 1. Preferably, in at least one method step, by means of at least one antenna 24a, in particular the at least one abovementioned antenna 24a, at least one electric and/or magnetic field is emitted, said field defining at least one detection area 20a about at least one machining tool 12a, in particular about the abovementioned machining tool 12a, of the power tool device 10a, and/or, by means of the at least one antenna 24a, at least one foreign body 16a, 18a is sensed on the basis of at least one change in at least one electric and/or magnetic field.

    [0093] Preferably, in at least one further method step, at least one movement characteristic of the at least one foreign body 16a, 18a and/or at least one distance 32a, 34a, 36a of the at least one foreign body 16a, 18a from the machining tool 12a is/are determined on the basis of at least one signal from at least one sensor unit 14a, in particular the abovementioned sensor unit 14a, of the power tool device 10a. As far as other method steps of the method for operating the power tool device 10a are concerned, reference may be made to the above description of the power tool device 10a, since this description can also be read analogously onto the method and therefore all the features relating to the power tool device 10a are considered to also be disclosed in relation to the method for operating the power tool device 10a.

    [0094] FIGS. 4 to 12 show nine further exemplary embodiments of the invention. The following descriptions and the drawings are restricted substantially to the differences between the exemplary embodiments, wherein, as far as identically referenced components are concerned, in particular as far as components with identical reference signs are concerned, reference may also be made in principle to the drawings and/or the description of the other exemplary embodiments, in particular FIGS. 1 to 3. To distinguish between the exemplary embodiments, the letter a is placed after the reference signs of the exemplary embodiment in FIGS. 1 to 3. In the exemplary embodiments in FIGS. 4 to 12, the letter a has been replaced by the letters b to j.

    [0095] FIG. 4 shows a first alternative power tool 72b in a schematic perspective illustration. The power tool 72b is in particular in the form of a hedge trimmer. The power tool 72b comprises in particular a power tool device 10b. Preferably, the power tool device 10b is intended for machining a workpiece by cutting and/or sawing. Preferably, the power tool device 10b comprises at least one motor-drivable machining tool 12b, in particular at least one blade. In particular, the machining tool 12b is mounted on a guide bar element 114b of the power tool device 10b. Preferably, the power tool device 10b comprises at least one, in particular capacitive, sensor unit 14b, which is configured to sense at least one foreign body 16b in at least one detection area 20b around the machining tool 12b, and at least one open-loop and/or closed-loop control unit 22b, which is configured to trigger at least one action on the basis of at least one signal from the sensor unit 14b. Preferably, the sensor unit 14b comprises at least one antenna 24b, which is configured to emit at least one electric and/or magnetic field, which defines the at least one detection area 20b, and/or to sense the at least one foreign body 16b on the basis of at least one change in at least one electric and/or magnetic field. Preferably, the open-loop and/or closed-loop control unit 22b is configured to trigger at least braking of the machining tool 12b on the basis of the at least one signal from the sensor unit 14b corresponding to sensing of the foreign body 16b in the detection area 20b, in particular by controlling a mechanical brake unit 60b of the power tool device 10b.

    [0096] Preferably, the open-loop and/or closed-loop control unit 22b is configured to determine a probability of contact of the at least one foreign body 16b with the moving machining tool 12b on the basis of at least one movement characteristic of the at least one foreign body 16b and/or of at least one distance 32b, 34b of the at least one foreign body 16b from the machining tool 12b and on the basis of a minimum time for braking the machining tool 12b to a standstill. In FIG. 4, the foreign body 16b, in particular a hand 78b of a user 48b, is illustrated for example at two different distances 32b, 34b from the machining tool 12b. Preferably, the open-loop and/or closed-loop control unit 22b is configured to trigger a different action on the basis of the probability of contact being below a probability threshold value than on the basis of the probability of contact being above the probability threshold value. For example, it is conceivable for the open-loop and/or closed-loop control unit 22b to be configured to trigger a movement of movable teeth 116b of the machining tool 12b, in particular of the hedge trimmer, into a closed position, in particular to prevent the user 48b being injured on the stationary but sharp-edged teeth 116b, on the basis of the probability of contact being below the probability threshold value. For example, it is conceivable for the open-loop and/or closed-loop control unit 22b to be configured to trigger a movement of the movable teeth 116b of the machining tool 12b into an opened position, in particular to prevent a body part 46b of the user 48b being severed by the teeth 116b moving into the closed position on contact with the machining tool 12b, on the basis of the probability of contact being above the probability threshold value. In particular, the open-loop and/or closed-loop control unit 22b is configured to control a motor 92b, driving the machining tool 12b, of the power tool device 10b to trigger a movement, in particular travel, of the teeth 116b of the machining tool 12b.

    [0097] Preferably, the power tool device 10b comprises at least one further sensor unit 40b, which has at least one contact sensor element 44b, arranged in the vicinity 42b, in the form of a guide region, of the machining tool 12b, in particular on an auxiliary handle 142b of the power tool device 10b, for sensing the at least one body part 46b of the user 48b. Preferably, the open-loop and/or closed-loop control unit 22b is configured to adapt a parameter at least partially autonomously on the basis of at least one signal from the further sensor unit 40b. In particular, the open-loop and/or closed-loop control unit 22b is configured to activate the motor 92b on the basis of the at least one signal from the further sensor unit 40b corresponding to sensing of the body part 46b of the user 48b.

    [0098] Preferably, the at least one antenna 24b is arranged parallel to a longitudinal axis 50b of the machining tool 12b. In particular, the at least one antenna 24b is arranged parallel to the longitudinal axis 50b of the machining tool 12b alternatively, as for example in the present exemplary embodiment, or additionally to being arranged in the form of a ring about the longitudinal axis 50b of the machining tool 12b. In particular, the sensor unit 14b can, in an alternative configuration, have at least two antenna 24b, wherein one antenna is arranged in the form of a ring about the longitudinal axis 50b of the machining tool 12b and a further antenna 24b is arranged parallel to the longitudinal axis 50b of the machining tool 12b. Preferably, a power tool 72b in the form of a hedge trimmer, as for example in the present exemplary embodiment, of a chain saw, of a router, of a trimmer, of a jigsaw or of a reciprocating saw comprises the power tool device 10b having the at least one antenna 24b that is arranged parallel to the longitudinal axis 50b of the machining tool 12b. In particular, the machining tool 12b can at least partially form the at least one antenna 24b and/or the at least one antenna 24b can be arranged at least partially on, in particular within, the machining tool 12b. Alternatively or additionally, it is conceivable for the at least one guide bar element 114b of the power tool device 10b, on which the machining tool 12b is at least partially mounted, to at least partially form the at least one antenna 24b and/or for the at least one antenna 24b, as for example in the present exemplary embodiment, to be arranged at least partially on, in particular within, the guide bar element 114b. Preferably, the at least one antenna 24b extends linearly.

    [0099] FIG. 5 shows a circuit diagram of a part of the sensor unit 14b. The sensor unit 14b comprises preferably at least one electrical or electronic shielding circuit 154b, which is configured to shield an electric and/or magnetic field, emitted by the antenna 24b, in at least one emission direction. By means of the shielding circuit 154b, in particular an emission direction of the antenna 24b is settable. The shielding circuit 154b is preferably in the form of a high-impedance circuit. The shielding circuit 154b comprises preferably at least one high-impedance electrical component. In particular, the antenna 24b and/or at least one tuning circuit 158b of the sensor unit 14b is/are connected to an input of the shielding circuit 154b. Preferably, at least one output of the shielding circuit 154b is connected to ground 156b. Preferably, the shielding circuit 154b has a higher impedance at the input of the shielding circuit 154b than at the output of the shielding circuit 154b. For example, an order of magnitude of the impedance at the input of the shielding circuit 154b is 100 MΩ and an order of magnitude of the impedance at the output of the shielding circuit 154b is 10 MΩ. However, it is also conceivable in principle for the orders of magnitude at the input and output to be different than the abovementioned values.

    [0100] FIG. 6 shows a second alternative power tool 72c in a schematic perspective illustration. The power tool 72c is in particular in the form of a nail gun. The power tool 72c comprises in particular a power tool device 10c. Preferably, the power tool device 10c is intended to machine a workpiece 76c by nailing. Preferably, the power tool device 10c comprises at least one motor-drivable machining tool 12c, in particular a plurality of machining tools 12c. In particular, the machining tools 12c are in the form of nails 80c. Preferably, the power tool device 10c comprises at least one, in particular capacitive, sensor unit 14c, which is configured to sense at least one foreign body 18c in at least one detection area 20c around the machining tool 12c, in particular the machining tool 12c presently to be dispensed, and at least one open-loop and/or closed-loop control unit 22c, which is configured to trigger at least one action on the basis of at least one signal from the sensor unit 14c. Preferably, the sensor unit 14c comprises at least one antenna 24c, which is configured to emit at least one electric and/or magnetic field, which defines the at least one detection area 20c, and/or to sense the at least one foreign body 18c on the basis of at least one change in at least one electric and/or magnetic field.

    [0101] Preferably, the open-loop and/or closed-loop control unit 22c is configured to trigger the at least one action on the basis of at least one parameter, in particular on the basis of at least one dimension 38c, of the machining tool 12c, in particular of the plurality of machining tools 12c. Preferably, the dimension 38c of the machining tools 12c is in the form of a maximum main extent of the machining tools 12c.

    [0102] In particular, the open-loop and/or closed-loop control unit 22c can be configured to prevent the at least one action on the basis of the at least one parameter, in particular on the basis of the at least one dimension 38c, of the machining tools 12c. Preferably, the open-loop and/or closed-loop control unit 22c is configured to trigger the at least one action on the basis of the at least one dimension 38c, in particular on the basis of the maximum main extent, of the machining tools 12c in the form of nails 80c. In particular, the open-loop and/or closed-loop control unit 22c is configured to control at least one dispensing unit 58c of the power tool device 10c, which is intended to dispense the machining tools 12c in the form of nails 80c, on the basis of the at least one dimension 38c, in particular on the basis of the maximum main extent, of the machining tools 12c in the form of nails 80c. In particular, it is conceivable for the open-loop and/or closed-loop control unit 22c to be configured to trigger dispensing of the machining tools 12c in the form of nails 80c on the basis of the dimension 38c, in particular the maximum main extent, of the machining tools 12c in the form of nails 80c being smaller than a determined distance 36c between the sensed foreign body 18c and the machining tools 12c, in particular the machining tool 12c presently to be dispensed. In particular, it is conceivable for the open-loop and/or closed-loop control unit 22c to be configured to prevent dispensing of the machining tools 12c in the form of nails 80c on the basis of the dimension 38c, in particular the maximum main extent, of the machining tools 12c in the form of nails 80c being greater than the determined distance 36c between the sensed foreign body 18c and the machining tools 12c, in particular the machining tool 12c presently to be dispensed.

    [0103] Preferably, the open-loop and/or closed-loop control unit 22c is configured to trigger the at least one action on the basis of at least one further parameter, for example a dispensing energy of the dispensing unit 58c, a material hardness of the workpiece 76c, a thickness of the workpiece 76c or the like. Alternatively or additionally to being in the form of a dimension 38c of the machining tools 12c, the at least one parameter of the machining tools 12c, in particular the at least one parameter of machining tools 12c that are not in the form of nails 80c, can also be in the form of a penetration depth of the machining tools 12c in the workpiece 76c, of an inertia characteristic of the machining tools 12c, of a rotational speed of the machining tools 12c or of some other parameter that appears to make sense to a person skilled in the art.

    [0104] Preferably, the power tool device 10c comprises at least one dispensing unit 58c, in particular the abovementioned dispensing unit 58c, for dispensing the at least one machining tool 12c, wherein the open-loop and/or closed-loop control unit 22c is configured to control the dispensing unit 58c to prevent or to enable the dispensing of the at least one machining tool 12c on the basis of the at least one signal from the sensor unit 14c. Preferably, the dispensing unit 58c is intended to dispense the machining tools 12c in the form of nails 80c. In particular, the dispensing unit 58c is intended to shoot the machining tools 12c. In particular, the dispensing unit 58c is intended to dispense, in particular shoot, a plurality of machining tools 12c one after another. In particular, the power tool 72c in the form of a nail gun comprises the power tool device 10c that comprises the dispensing unit 58c. In particular, the power tool device 10c can comprise at least one magazine unit 118c, which is intended to receive a plurality of machining tools 12c and/or to feed the plurality of machining tools 12c to the dispensing unit 58c. Preferably, the dispensing unit 58c comprises at least one release bracket 120c, which, to enable dispensing of the machining tools 12c, in particular in addition to be controlled by the open-loop and/or closed-loop control unit 22c, is actuable, in particular pressable, in particular counter to a dispensing direction 122c of the dispensing unit 58c. Preferably, the release bracket 120c forms the antenna 24c of the sensor unit 14c. Alternatively or additionally, it is conceivable for the antenna 24c to be arranged on the release bracket 120c, on a machining tool outlet 138c and/or on a machining tool guide 140c of the dispensing unit 58c.

    [0105] Preferably, the open-loop and/or closed-loop control unit 22c is configured to control the dispensing unit 58c to prevent the dispensing of the machining tools 12c on the basis of at least one signal from the sensor unit 14c corresponding to sensing of the at least one foreign body 18c in the detection area 20c, in particular in a dispensing area 124c of the dispensing unit 58c. In the present exemplary embodiment, the foreign body 18c, in particular in the form of a power line 126c, is arranged in the dispensing area 124c of the dispensing unit 58c, in particular in the vicinity of the workpiece 76c, which is in particular in the form of wall cladding. In particular, it is conceivable for the open-loop and/or closed-loop control unit 22c to additionally be configured to trigger an output of a warning signal on the basis of the signal from the sensor unit 14c corresponding to the sensing of the foreign body 18c in the detection area 20c, in particular in the dispensing area 124c of the dispensing unit 58c. Preferably, the open-loop and/or closed-loop control unit 22c is configured to control the dispensing unit 58c to release the machining tools 12c on the basis of at least one signal from the sensor unit 14c corresponding to a lack of sensing of a foreign body 18c in the detection area 20c, in particular in the dispensing area 124c of the dispensing unit 58c. In particular, the open-loop and/or closed-loop control unit 22c can be configured to compare a determined position of the sensed foreign body 18c with the dispensing area 124c of the dispensing unit 58c and to control the dispensing unit 58c in particular on the basis of the comparison. In particular, the open-loop and/or closed-loop control unit 22c can be configured to control the dispensing unit 58c to release the machining tools 12c on the basis of at least one signal from the sensor unit 14c corresponding to sensing of at least one foreign body 18c in the detection area 20c and on the basis of a determined position of the foreign body 18c outside the dispensing area 124c of the dispensing unit 58c.

    [0106] FIG. 7 shows a third alternative power tool 72d in a schematic perspective illustration. The power tool 72d is in particular in the form of a jigsaw. The power tool 72d comprises in particular a power tool device 10d. Preferably, the power tool device 10d is intended to machine a workpiece by cutting and/or sawing. Preferably, the power tool device 10d comprises at least one motor-drivable machining tool 12d. In particular, the machining tool 12d is in the form of a saw blade, in particular of a jigsaw blade. Preferably, the power tool device 10d comprises at least one, in particular capacitive, sensor unit 14d, which is configured to sense at least one foreign body in at least one detection area 20d around the machining tool 12d, and at least one open-loop and/or closed-loop control unit 22d, which is configured to trigger at least one action on the basis of at least one signal from the sensor unit 14d. Preferably, the sensor unit 14d comprises at least one antenna 24d, which is configured to emit at least one electric and/or magnetic field, which defines the at least one detection area 20d, and/or to sense the at least one foreign body on the basis of at least one change in at least one electric and/or magnetic field. Preferably, the open-loop and/or closed-loop control unit 22d is configured to trigger at least one braking of the machining tool 12d on the basis of the at least one signal from the sensor unit 14d corresponding to sensing of a foreign body in the detection area 20d, in particular by controlling a mechanical brake unit 60d of the power tool device 10d.

    [0107] Preferably, the at least one antenna 24d is integrated in at least one mechanical protective element 52d in the vicinity 42d of the machining tool 12d, and/or the at least one antenna 24d is configured to replace the mechanical protective element 52d. Preferably, the power tool device 10d has the mechanical protective element 52d for protecting the machining tool 12d, in particular from foreign bodies, and/or for protecting foreign bodies, in particular body parts of a user, from the machining tool 12d. The mechanical protective element 52d is arranged in particular in the vicinity 42d of the machining tool 12d. Preferably, the mechanical protective element 52d covers the machining tool 12d at least partially, and encloses the machining tool 12d in particular at least partially. Preferably, the mechanical protective element 52d is in the form of a guard bracket, as for example in the present exemplary embodiment, of a protective hood or of some other mechanical protective element that appears to make sense to a person skilled in the art. In particular, the mechanical protective element 52d can at least partially form the at least one antenna 24d, in particular be formed from a metal, and/or the at least one antenna 24d can be arranged at least partially on, in particular within, the mechanical protective element 52d. In the present exemplary embodiment, the mechanical protective element 52d forms the antenna 24d for example. Alternatively, it is conceivable for the antenna 24d to be arranged on, in particular within, a guide element 98d of the power tool device 10d, in particular a sliding shoe, and/or the machining tool 12d, and/or to be formed by the machining tool 12d. Also alternatively, it is conceivable for the at least one antenna 24d to be configured to replace the mechanical protective element 52d, in particular a protective function of the mechanical protective element 52d. In particular, the at least one antenna 24d is configured to provide virtual shielding of the machining tool 12d, in particular in the form of the detection area 20d. In particular, as an alternative to mechanical protection by the mechanical protective element 52d, in order to reduce a risk of injury by the machining tool 12d and/or a risk of damage to the machining tool 12d, the at least one action, in particular braking of the machining tool 12d, moving the machining tool 12d away from a risk area 82d, mechanical shielding of the machining tool 12d or the like is able to be triggered on the basis of sensing of the foreign body by the at least one antenna 24d. In particular, the power tool device 10d can, in an alternative configuration, be formed free of the mechanical protective element 52d.

    [0108] FIG. 8 shows a fourth alternative power tool 72e in a schematic perspective illustration. The power tool 72e is in particular in the form of garden shears. The power tool 72e comprises in particular a power tool device 10e. Preferably, the power tool device 10e is intended to machine a workpiece by cutting. Preferably, the power tool device 10e comprises at least one motor-drivable machining tool 12e. In particular, the power tool device 10e comprises a further, in particular stationary, machining tool 128e, which is intended to cooperate with the motor-drivable machining tool 12e. In particular, the machining tools 12e, 128e are in the form of blades. Preferably, the power tool device 10e comprises at least one, in particular capacitive, sensor unit 14e, which is configured to sense at least one foreign body in at least one detection area 20e around the machining tools 12e, 128e, and at least one open-loop and/or closed-loop control unit 22e, which is configured to trigger at least one action on the basis of at least one signal from the sensor unit 14e. Preferably, the sensor unit 14e comprises at least one antenna 24e, which is configured to emit at least one electric and/or magnetic field, which defines the at least one detection area 20e, and/or to sense the at least one foreign body on the basis of at least one change in at least one electric and/or magnetic field. In particular, the further machining tool 128e forms the antenna 24e. Alternatively or additionally, it is conceivable for the machining tool 12e to form the antenna 24e and/or for the antenna 24e to be arranged on, in particular within, the machining tool 12e and/or the further machining tool 128e.

    [0109] Preferably, the power tool device 10e comprises at least one mechanical brake unit 60e that is controllable by the open-loop and/or closed-loop control unit 22e, is intended to brake the machining tool 12e and is at least partially in the form of at least one self-locking gear 62e, in particular of a worm gear. Preferably, the mechanical brake unit 60e is intended to mechanically brake the at least one, in particular moving, machining tool 12e, in particular until the machining tool 12e is at a standstill. In particular, the mechanical brake unit 60e, in particular in addition to being at least partially formed by the self-locking gear 62e, may comprise at least one mechanical brake element, in particular a brake shoe, a wrap spring, a blocking pin or the like, which, to effect active braking of the machining tool 12e, is able to be coupled by a force- and/or form-fit to the machining tool 12e and/or to an output shaft (not illustrated here). Preferably, the mechanical brake unit 60e is intended to brake the machining tool 12e at the latest 200 milliseconds after triggering of the mechanical braking, until the machining tool 12e is at a standstill.

    [0110] Preferably the power tool 72e in the form of garden shears comprises the power tool device 10e that comprises the mechanical brake unit 60e which is formed at least partially by the at least one self-locking gear 62e, in particular by the worm gear. Preferably, the gear 62e is intended to transform a movement of a motor 92e of the power tool device 10e into a drive for the at least one machining tool 12e. Preferably, the gear 62e and the motor 92e are provided for motor support of manual actuation of the at least one machining tool 12e, in particular a cutting movement of the garden shears. Preferably, the gear 62e has a transmission ratio, in particular of a speed of the motor 92e to a speed of the machining tool 12e, of at least 1:50, preferably of at least 1:75 and particularly preferably of at least 1:100. Preferably, the gear 62e is able to be driven via a driveshaft of the motor 92e. Preferably, the gear 62e is not able to be driven via the output shaft, on which the machining tool 12e is mounted. Preferably, the gear 62e is in the form of a dynamically self-locking gear. In particular, the gear 62e is in the form of a worm gear which has a maximum degree of efficiency of less than 0.5. Preferably, the gear 62e is intended to stop a movement of the at least one machining tool 12e on the basis of a stopping of the motor 92e. In particular, the open-loop and/or closed-loop control unit 22e is configured to effect and/or trigger motor braking of the motor 92e on the basis of at least one signal from the sensor unit 14e. In particular, the open-loop and/or closed-loop control unit 22e is configured to switch off, to short-circuit, to reverse the polarity of or similarly act on the motor 92e, in particular electric motor, driving the machining tool 12e, in order to effect motor braking.

    [0111] FIG. 9 shows a fifth alternative power tool 72f in a schematic perspective illustration. The power tool 72f is in particular in the form of a milling machine, in particular of a router. The power tool 72f comprises in particular a power tool device 10f. Preferably, the power tool device 10f is intended to machine a workpiece by milling. Preferably, the power tool device 10f comprises at least one motor-drivable machining tool 12f, in particular a milling tool. Preferably, the power tool device 10f comprises at least one, in particular capacitive, sensor unit 14f, which is configured to sense at least one foreign body in at least one detection area 20f around the machining tool 12f, and at least one open-loop and/or closed-loop control unit 22f, which is configured to trigger at least one action on the basis of at least one signal from the sensor unit 14f. Preferably, the sensor unit 14f comprises at least one antenna 24f, which is configured to emit at least one electric and/or magnetic field, which defines the at least one detection area 20f, and/or to sense the at least one foreign body on the basis of at least one change in at least one electric and/or magnetic field.

    [0112] Preferably, the open-loop and/or closed-loop control unit 22f is configured to trigger at least one braking of the machining tool 12f on the basis of the at least one signal from the sensor unit 14f corresponding to sensing of a foreign body in the detection area 20f, in particular by controlling a mechanical brake unit 60f of the power tool device 10f. Alternatively or additionally, it is conceivable for the power tool device 10f to have at least one protective unit and/or a retraction unit, which is/are controllable by the open-loop and/or closed-loop control unit 22f on the basis of the at least one signal from the sensor unit 14f.

    [0113] Preferably, the power tool device 10f comprises at least one housing 54f from which the sensor unit 14f is able to be uncoupled, wherein the sensor unit 14f has at least one, in particular wireless, communications unit 56f for providing the at least one signal to the open-loop and/or closed-loop control unit 22f. In particular, the power tool device 10f can be operable in a state uncoupled from the sensor unit 14f, in particular in a state free from a connection for signal transmission purposes between the sensor unit 14f and the open-loop and/or closed-loop control unit 22f, in particular free of comfort functions and safety functions based on the sensor unit 14f. Preferably, the sensor unit 14f is able to be used with, in particular able to be coupled to, different power tool devices 10f. Preferably, the housing 54f of the power tool device 10f and the sensor unit 14f, in particular a housing 130f of the sensor unit 14f, can have coupling interfaces 132f, 134f, for example bayonet connections, latching elements, plugs or the like, for mechanical, in particular mechanical and electrical, coupling. The housing 130f of the sensor unit 14f forms in particular a guide element 98f, in particular a sliding shoe. In particular, the antenna 24f is arranged on, in particular within, the housing 130f of the sensor unit 14f. In the present exemplary embodiment, the housing 54f of the power tool device 10f and the sensor unit 14f, in particular the housing 130f of the sensor unit 14f, have for example mechanical coupling interfaces 132f, 134f. In particular, the sensor unit 14f, in particular the housing 130f of the sensor unit 14f, has two coupling interfaces 134f in the form of coupling rods. In particular, the housing 54f of the power tool device 10f has two coupling interfaces 132f, in the form of coupling receptacles, for receiving the coupling interfaces 134f of the sensor unit 14f. In particular, in an alternative configuration, an electrical coupling interface can at least partially form the communications unit 56f of the sensor unit 14f and/or a communications unit 136f of the power tool device 10f. In particular, the communications unit 56f of the sensor unit 14f is configured to transmit the at least one signal to the open-loop and/or closed-loop control unit 22f via the communications unit 136f of the power tool device 10f. The communications unit 56f, 136f, in the form of a wireless communications unit, of the sensor unit 14f and/or of the power tool device 10f can in particular be in the form of a WLAN module, of a radio module, of a Bluetooth module, of an NFC module or the like. A communications unit 56f, 136f, in the form of a wired communications unit in an alternative configuration, of the sensor unit 14f and/or of the power tool device 10f can, alternatively or additionally to being formed by the at least one coupling interface 132f, 134f, be in particular in the form of a USB connection, of an Ethernet connection, of a coaxial connection or the like.

    [0114] FIG. 10 shows a sixth alternative power tool 72g in a schematic perspective illustration. The power tool 72g is in particular in the form of a saw, in particular of a chain saw. The power tool 72g comprises in particular a power tool device 10g. Preferably, the power tool device 10g is intended to machine a workpiece by cutting and/or sawing. Preferably, the power tool device 10g comprises at least one motor-drivable machining tool 12g, in particular a saw chain. In particular, the machining tool 12g is mounted on a guide bar element 114g of the power tool device 10g. Preferably, the power tool device 10g comprises at least one, in particular capacitive, sensor unit 14g, which is configured to sense at least one foreign body in at least one detection area 20g around the machining tool 12g, and at least one open-loop and/or closed-loop control unit 22g, which is configured to trigger at least one action on the basis of at least one signal from the sensor unit 14g. Preferably, the sensor unit 14g comprises at least one antenna 24g, which is configured to emit at least one electric and/or magnetic field, which defines the at least one detection area 20g, and/or to sense the at least one foreign body on the basis of at least one change in at least one electric and/or magnetic field. The antenna 24g is arranged in particular on, in particular within, the guide bar element 114g. In particular, the antenna 24g extends non-linearly. Preferably, the antenna 24g is arranged parallel to the machining tool 12g. Alternatively or additionally, it is conceivable for the guide bar element 114g and/or the machining tool 12g to form the antenna 24g and/or for the antenna 24g to be arranged on, in particular within, the machining tool 12g. Preferably, the open-loop and/or closed-loop control unit 22g is configured to trigger at least one braking of the machining tool 12g on the basis of the at least one signal from the sensor unit 14g corresponding to sensing of a foreign body in the detection area 20g, in particular by controlling a mechanical brake unit 60g of the power tool device 10g. Preferably, the mechanical brake unit 60g is in the form of a band brake and/or provided in addition to a band brake. Alternatively or additionally, it is conceivable for the open-loop and/or closed-loop control unit 22g to be configured to trigger moving of a recoil bracket of the power tool device 10g in the direction of the machining tool 12g on the basis of the at least one signal from the sensor unit 14g corresponding to sensing of a foreign body in the detection area 20g.

    [0115] FIG. 11 shows a seventh alternative power tool 72h in a schematic perspective illustration. The power tool 72h is in particular in the form of a saw, in particular of a reciprocating saw. The power tool 72h comprises in particular a power tool device 10h. Preferably, the power tool device 10h is intended to machine a workpiece by cutting and/or sawing. Preferably, the power tool device 10h comprises at least one motor-drivable machining tool 12h, in particular a saw blade. Preferably, the power tool device 10h comprises at least one, in particular capacitive, sensor unit 14h, which is configured to sense at least one foreign body in at least one detection area 20h around the machining tool 12h, and at least one open-loop and/or closed-loop control unit 22h, which is configured to trigger at least one action on the basis of at least one signal from the sensor unit 14h. Preferably, the sensor unit 14h comprises at least one antenna 24h, which is configured to emit at least one electric and/or magnetic field, which defines the at least one detection area 20h, and/or to sense the at least one foreign body on the basis of at least one change in at least one electric and/or magnetic field. Preferably, a mechanical protective element 52h of the power tool device 10h in the vicinity 42h of the machining tool 12h forms the antenna 24h. Preferably, the open-loop and/or closed-loop control unit 22h is configured to trigger at least one braking of the machining tool 12h on the basis of the at least one signal from the sensor unit 14h corresponding to sensing of a foreign body in the detection area 20h, in particular by controlling a mechanical brake unit 60h of the power tool device 10h.

    [0116] FIG. 12 shows an eighth alternative power tool 72i in a schematic perspective illustration. The power tool 72i is in particular in the form of shears, in particular of grass shears. The power tool 72i comprises in particular a power tool device 10i. Preferably, the power tool device 10i is intended to machine a workpiece by cutting. Preferably, the power tool device 10i comprises at least one motor-drivable machining tool 12i, in particular a blade. In particular, the power tool device 10i comprises a further, in particular stationary machining tool 128i, in particular a blade, which is intended to cooperate with the machining tool 12i. Preferably, the power tool device 10i comprises at least one, in particular capacitive, sensor unit 14i, which is configured to sense at least one foreign body in at least one detection area 20i around the machining tools 12i, 128i, and at least one open-loop and/or closed-loop control unit 22i, which is configured to trigger at least one action on the basis of at least one signal from the sensor unit 14i. Preferably, the sensor unit 14i comprises at least one antenna 24i, which is configured to emit at least one electric and/or magnetic field, which defines the at least one detection area 20i, and/or to sense the at least one foreign body on the basis of at least one change in at least one electric and/or magnetic field. Preferably, the further, in particular stationary, machining tool 128i forms the antenna 24i. Alternatively or additionally, it is conceivable for the machining tool 12i to form the antenna 24i and/or for the antenna 24i to be arranged on, in particular within, the machining tool 12i and/or the further machining tool 128i. Preferably, the open-loop and/or closed-loop control unit 22i is configured to trigger at least one braking of the machining tool 12i on the basis of the at least one signal from the sensor unit 14i corresponding to sensing of a foreign body in the detection area 20i, in particular by controlling a mechanical brake unit 60i of the power tool device 10i.

    [0117] FIG. 13 shows a ninth alternative power tool 72j in a schematic perspective illustration. The power tool 72j is in particular in the form of shears, in particular of universal shears. The power tool 72j comprises in particular a power tool device 10j. Preferably, the power tool device 10j is configured to machine a workpiece by cutting. Preferably, the power tool device 10j comprises at least one motor-drivable machining tool 12j, in particular a rotary blade. Preferably, the power tool device 10j comprises at least one, in particular capacitive, sensor unit 14j, which is configured to sense at least one foreign body in at least one detection area 20j around the machining tool 12j, and at least one open-loop and/or closed-loop control unit 22j, which is configured to trigger at least one action on the basis of at least one signal from the sensor unit 14j. Preferably, the sensor unit 14j comprises at least one antenna 24j, which is configured to emit at least one electric and/or magnetic field, which defines the at least one detection area 20j, and/or to sense the at least one foreign body on the basis of at least one change in at least one electric and/or magnetic field.

    [0118] Preferably, an output shaft 90j, on which the machining tool 12j is mounted, forms the antenna 24j. Alternatively or additionally, it is conceivable for the machining tool 12j to form the antenna 24j and/or for the antenna 24j to be arranged on, in particular within, the machining tool 12j and/or the output shaft 90j. Preferably, the open-loop and/or closed-loop control unit 22j is configured to trigger braking of the machining tool 12j on the basis of a signal from the sensor unit 14j corresponding to sensing of a foreign body in the detection area 20j, in particular by controlling a mechanical brake unit 60j of the power tool device 10j. Alternatively or additionally, it is conceivable for the open-loop and/or closed-loop control unit 22j to be configured to trigger an output of an, in particular haptic, warning signal on the basis of the signal from the sensor unit 14j corresponding to sensing of a foreign body in the detection area 20j, in particular by controlling a vibratory unit 144j of the power tool device 10j. The vibratory unit 144j is arranged in particular on a housing 54j of the power tool device 10j, in particular on a handle 146j formed at least partially by the housing 54j.