TOOL DEVICE AND METHOD

Description

[0001] The invention relates to a tool device with a driveable tool. The tool device comprises a shaft coupled to the tool. Advantageously, the tool can be driven via the shaft.

[0002] EP 1 234 285 B1 describes a table saw with a braking mechanism comprising at least one pawl which engages with the saw blade to stop the rotating saw blade.

[0003] DE 60 2004 005115 T2 describes a saw shaft brake with a sliding block which, in a waiting position, does not contact an expanded diameter element of a saw shaft.

[0004] US Patent 7 055 417 B1 describes a braking system with multiple pawls that can be engaged with a shaft to stop a saw blade.

[0005] US 4,072,218 A describes a spindle braking mechanism for a milling machine. Two brake shoes can be pivoted to establish braking contact with the machine spindle. US 4,072,218 A discloses a tooling device according to the preamble of claim 1 and a method according to the preamble of claim 13.

[0006] FR 2 739 586 A1 describes a saw blade brake with a coil spring wound around a shaft.

[0007] One object of the invention is to provide a tool device that can be operated with less effort.

[0008] The problem is solved by a tool device according to claim 1. The tool device comprises several brake elements arranged circumferentially around the shaft. The tool device is designed to move the several brake elements from a release state to a braking state during a braking process. In the braking state, the several brake elements are in contact with the shaft and thereby exert a braking force on the shaft, thus braking the tool. In the release state, the several brake elements are not in contact with the shaft.The tool device is designed to move the multiple brake bodies from the release state to a carrying state and from the carrying state to the braking state during the braking process, whereby the multiple brake bodies are carried along in the carrying state by a movement of the shaft, so that the movement of the multiple brake bodies into the braking state is supported by the movement of the shaft.

[0009] In the EP 1 234 285 B1 mentioned at the beginning, a pawl engages with the saw blade to stop it. This usually results in damage to both the saw blade and the pawl, requiring both to be replaced before the table saw can continue to be used.

[0010] In contrast, with the described tool device, the tool and / or the brake elements conveniently remain undamaged and / or usable even after the tool has been braked, so that no replacement is necessary for further operation.

[0011] For this reason, the described tool device can be operated with less effort.

[0012] Advantageous further training is the subject of the sub-claims.

[0013] The invention further relates to a method for braking a tool coupled to a shaft, comprising the step of: moving several brake bodies, which are arranged distributed circumferentially around the shaft, from a release state to a guided state and from the guided state to a braking state, wherein in the release state the several brake bodies are not in contact with the shaft, in the braking state the several brake bodies are in contact with the shaft and thereby exert a braking force on the shaft, so that the tool is braked, and in the guided state the several brake bodies are guided by a movement of the shaft, so that the movement of the several brake bodies into the braking state is supported by the movement of the shaft.

[0014] Further exemplary details and embodiments are explained below with reference to the figures. Figure 1 is a schematic representation of a tool device, Figure 2 is a sectional view of a braking device and a shaft of the tool device, wherein the tool device is in a braking state, Figure 3 is a sectional view of a braking device and a shaft of the tool device, wherein the tool device is in a release state, Figure 4 is a sectional view of a single brake body, and Figure 5 is a perspective view of an actuation section.

[0015] The following explanation refers to the directions "x", "y", and "z" shown in the figures (The x-direction runs in the Figures 1 to 4(perpendicular to the drawing plane). The x-direction, y-direction, and z-direction are orthogonal to each other. The x-direction and y-direction can also be referred to as the horizontal direction, and the z-direction as the vertical direction. The directions "radial direction" and "axial direction" mentioned below are to be understood specifically in relation to the longitudinal axis of shaft 2.

[0016] The Figure 1 Figure 1 shows a tool device 10 with a driveable tool 1. The tool device 10 comprises a shaft 2 coupled to the tool 1, via which the tool 1 can be expediently driven.

[0017] The tool device 10 further comprises a plurality of brake bodies 3, which are shown by way of example in the Figures 2 and 3 shown. For the sake of clarity, the following are shown in the Figures 2 and 3Only three of the 14 brake bodies shown are marked with the reference symbol "3". The brake bodies 3 are arranged in a circumferential direction 4 around the shaft 2.

[0018] The tool device 10 is designed to move the brake bodies 3 from a release state to a braking state during a braking process.

[0019] In the braking state, exemplified in the Figure 2 As shown, the brake elements 3 are in contact with the shaft 2. Through this contact, the brake elements 3 exert a braking force on the shaft 2. This braking force slows down the shaft 2 and thus also the tool 1.

[0020] In the release state, the brake bodies 3 are not in contact with the shaft 2.

[0021] Further exemplary details are explained below. First, regarding tool device 10: Tool device 10 is, by way of example, a saw, in particular a saw with a rotating saw blade as the tool 1. Preferably, tool device 10 is a table circular saw. Alternatively, tool device 10 can also be configured as another type of tool device. In particular, tool device 10 can be configured as a stationary or semi-stationary machine. Furthermore, tool device 10 can be configured as a hand-held machine, in particular a hand-held machine tool. Preferably, tool device 10 is configured as a miter saw, plunge saw, pendulum guard saw, band saw, jigsaw, router, and / or angle grinder. Tool device 10 is, in particular, a power tool.

[0022] The tool device 10 comprises, by way of example, the tool 1, the shaft 2, a drive unit 5, an actuator unit 6, and a control unit 7. Furthermore, the tool device 10 expediently comprises a support structure 8 and / or a support surface 9.

[0023] The support structure 8 is designed as an exemplary housing. The drive unit 5, the actuator unit 6 and / or the control unit 7 are expediently housed in the support structure 8.

[0024] The support surface 9 is shown as an example on the upper side of the support structure 8. The support surface 9 serves to support a workpiece 11 while the workpiece 11 is machined with the tool 1. For example, the support surface 9 represents an xy-plane. For example, the tool 1 projects out from the support surface 9, particularly in the z-direction.

[0025] The drive unit 5 is designed as a rotary drive, in particular as an electric rotary drive. The drive unit 5 serves to drive the tool 1, in particular to set the tool 1 into rotation, preferably in a clockwise direction. The tool 1 is coupled to the drive unit 5 via the shaft 2. The drive unit 5 is designed to drive the shaft 2, in particular to set it into rotation, which in turn drives the tool 1. By way of example, the tool 1 is connected to the shaft 2 in a rotationally fixed manner, so that the tool 1 rotates with the rotating shaft 2.

[0026] Shaft 2 is in particular a shaft of the drive train of the tool device 10. Shaft 2 and tool 1 are expediently mounted rotatably relative to the support structure 8.

[0027] Shaft 2 is aligned with its longitudinal axis parallel to the x-direction. For example, shaft 2 has a circular cylindrical shape. The axis of rotation of tool 1 is advantageously aligned parallel to the x-direction. For example, shaft 2 and tool 1 are aligned coaxially with each other.

[0028] The actuator unit 6 is conveniently used to selectively place the brake bodies 3 into either the braking state or the release state, as will be explained in more detail below.

[0029] The control unit 7 is suitably designed to provide a drive unit control signal to the drive unit 5 in order to cause the drive unit 5 to drive the tool 1.

[0030] The control unit 7 is expediently further configured to provide the actuator unit 6 with an actuator unit control signal to cause the actuator unit 6 to put the brake bodies 3 into the braking state and / or the release state.

[0031] The control unit 7 is also expediently designed to detect an emergency condition and to trigger the braking process on the basis of the detected emergency condition, in particular by providing the actuator unit control signal to the actuator unit 6.

[0032] The emergency situation refers in particular to a potentially dangerous situation for a user, in which the user could be injured by the tool and / or the workpiece, for example.

[0033] The control unit 7 is suitably designed to detect the emergency condition based on a detected contact between the tool 1 and the human body, for example a finger.

[0034] The control unit 7 is expediently designed to detect the emergency condition of a kickback.

[0035] The term "kickback" refers in particular to a condition in which, during the machining of a workpiece by the tooling device, a sudden and unexpected force occurs between the tooling device and the workpiece, causing the tooling device and / or the workpiece to move.

[0036] Preferably, the tool device 10, in particular the control unit 7, is configured to supply an electrical detection signal to the tool 1 and to detect the emergency state based on a change in the detection signal. Advantageously, the tool device 10, in particular the control unit 7, is configured to supply the electrical detection signal to the tool 1 by capacitive coupling. Advantageously, the tool device 10, in particular the control unit 7, is configured to detect the emergency state, in particular contact between the tool 1 and the human body, based on a capacitive change. Further details on how the detection of the emergency state can be implemented by way of example are described in EP 1 234 285 B1.

[0037] With reference to the Figures 2 and 3 The braking device 12 will be discussed in more detail below.

[0038] The tooling device 10 comprises a braking device 12, which includes the aforementioned brake elements 3 with which the shaft 2, and thus also the tool 1, can be braked. The tooling device 10 is configured to perform the braking process of the tool 1 using the braking device 12. In particular, the tooling device 10 is configured to bring the tool 1 to a standstill within 5 ms or less by performing the braking process, expediently from a driven, in particular rotating, state of the tool 1, in which machining of the workpiece 11 is taking place or can take place.

[0039] The braking device 12 is preferably designed as a freewheel brake. Advantageously, the braking device 12 is integrated into the tooling device 10. The braking device 12 is, in particular, an actively switched brake (preferably via the control unit 7 and / or the actuator unit 6). The braking device 12 is, in particular, designed to be reversible, so that it can be switched from the braking state back to the release state (and from there, advantageously, back to the braking state), preferably without having to replace any component of the braking device 12.

[0040] The braking device 12 comprises, by way of example, the brake bodies 3, a braking section 14, a holding section 15 and an actuating section 16.

[0041] The braking device 12 functions in particular as follows: To brake the tool 1, the actuating section 16 is expediently moved, in particular rotated, by the actuator unit. The movement of the actuating section 16 moves the brake elements 3 from the release state to the braking state, in particular by pivoting the brake elements 3. On their way from the release state to the braking state, the brake elements 3 come into contact with the shaft 2 and are assisted in their movement towards the braking state by the rotational movement of the shaft 2. In the braking state, the brake elements 3 are clamped between the shaft 2 and the braking section 14. In particular due to support, especially radial and / or tangential support, of the brake elements 3 on the braking section 14, the brake elements 3 exert a braking force on the shaft 2.The braking force slows down shaft 2 and thus also tool 1, especially until tool 1 comes to a standstill.

[0042] The following section will discuss in detail exemplary designs of the individual components of the brake system 12: First, let's look at braking section 14:

[0043] The brake section 14 is, by way of example, part of the support structure 8 or rotationally fixed to the support structure 8, in particular to the support structure 8 designed as a housing. The brake section 14 is in particular a stationary section, especially relative to the shaft 2. Advantageously, the brake section 14 does not rotate with the shaft 2.

[0044] According to one possible embodiment, the brake section 14 is designed as a brake drum.

[0045] For example, the brake element 14 surrounds the shaft 2, particularly in the circumferential direction 4. In particular, the brake element 14 encompasses the shaft 2. Advantageously, the brake element 14 also surrounds the brake bodies 3 and in particular the holding section 15 and / or the actuating section 16.

[0046] The brake element 14 defines, by way of example, a cylindrical interior space 19 in which the brake bodies 3 and the shaft 2 are arranged. Advantageously, the retaining section 15 and / or the actuating section 16 are also arranged in the cylindrical interior space 19.

[0047] The braking section 14 expediently provides a braking surface 21. The braking surface 21 is expediently the inwardly facing surface of the braking section 14, in particular the surface defining the cylindrical interior 19. The braking surface 21 exemplarily has the shape of a cylindrical shell. Expediently, the braking surface 21 supports the brake elements 3.

[0048] The brake section 14 is expediently designed as an outer ring. The brake elements 3 are expediently supported on the inner circumference of the brake section 14.

[0049] Next, we will discuss brake bodies 3: For example, 14 brake bodies 3 are present.

[0050] It is advantageous to have more or fewer brake bodies 3. Preferably, at least 3, 5, 7, 10, 12 or 14 brake bodies 3 are present.

[0051] The brake bodies 3 are expediently separate parts, in particular individual parts.

[0052] The brake elements 3 are distributed around the shaft 2 – in particular around the longitudinal axis of the shaft 2. The brake elements 3 are arranged circumferentially 4 around the shaft 2. The brake elements 3 are advantageously located in an annular region that surrounds the shaft 2 and / or is arranged coaxially to the shaft 2. Preferably, the brake elements 3 are located exclusively in this annular region. The annular region is in particular a radial region with respect to the shaft 2. The annular region is located in particular between the shaft 2 and the brake section 14.

[0053] The brake elements 3 are advantageously arranged uniformly around the shaft 2, in particular at equal angular intervals. The brake elements 3 are advantageously located on a circular path that encircles the shaft 2.

[0054] The brake elements 3 are advantageously arranged between the shaft 2 and the brake section 14, particularly in a radial direction (relative to the longitudinal axis of the shaft 2). Advantageously, the brake elements 3 are supported radially on the brake element 14. The brake elements 3 are particularly radially fixed to the brake section 14. The brake elements 3 are particularly circumferentially fixed relative to the brake section 14. Advantageously, the brake elements 3 are circumferentially fixed to the retaining section 15. The retaining section 15 is advantageously rotationally fixed to the brake section 14.

[0055] The brake elements 3 are advantageously mounted so as to be pivotable, preferably relative to the brake section 14 and / or the holding section 15. Each brake element 3 is advantageously mounted so as to be pivotable about its own (imaginary) pivot axis. The pivot axes of the brake elements 3 are advantageously parallel to the x-direction and / or parallel to the longitudinal axis of the shaft 2.

[0056] Preferably, the brake elements 3 are pre-tensioned and / or spring-loaded relative to the braking section 14 and / or the holding section 15. The pre-tensioning and / or spring-loading of the brake elements 3 expediently exerts a torque on each brake element 3 relative to the respective pivot axis, particularly in a clockwise direction.

[0057] The brake bodies 3 each comprise a first contact section 17 with a ramp-shaped first contact contour 18, which is in contact with the shaft 2 in the braking state.

[0058] With reference to the Figure 4An exemplary design of a brake element 3 will be explained. The explanation should apply to several, and in particular to all, brake elements 3 of the brake assembly 12.

[0059] The brake body 3 extends, for example, along a body axis 22. The body axis 22 advantageously lies in a yz-plane and preferably runs orthogonally to the x-direction and / or longitudinal axis of the shaft 2. The extent of the brake body 3 along the body axis 22 is preferably greater than the extent of the brake body 3 along a transverse axis 23, which runs orthogonally to the body axis 22 and lies in a yz-plane. For example, the extent of the brake body 3 in the direction of the body axis 22 is at least 1.5 times greater than the extent of the brake body 3 in the direction of the transverse axis 23.

[0060] Alternatively, the extent of the brake body 3 along the body axis 22 is equal to or less than the extent of the brake body along the transverse axis 23.

[0061] The brake body 3 has a first side 31 and a second side 32, each located on opposite sides of the body axis 22.

[0062] The brake body 3 includes, by way of example, a bearing section 24, which is arranged centrally in the direction of the body axis 22. The bearing section 24 preferably comprises a first convex region 25 and a second convex region 26. The convex regions 25, 26 are, by way of example, oriented in opposite directions and / or perpendicular to the transverse axis 23. By way of example, the first convex region 25 lies on the first side 31 and the second convex region 26 on the second side 32. By way of example, the convex regions 25, 26 each have the shape of a circular segment.

[0063] The brake body 3 is pivotably mounted on the holding section 15 by means of its bearing section 24, in particular the convex areas 25, 26. The shape of the convex areas 25, 26 expediently defines the pivoting movement that the brake body 3 can perform.

[0064] For example, a first contact section 17 adjoins the bearing section 24, in particular in a first direction along the body axis 22. The first contact section 17 serves to contact the shaft 2 in the braking state.

[0065] The contact section 17 comprises a ramp-shaped first contact contour 18, which is in contact with the shaft 2 when braking. The contact contour 18 is, by way of example, oriented perpendicular to the body axis 22. The contact contour 18 has, by way of example, a curved, in particular convex, profile.

[0066] Advantageously, the radius of the brake body 3 changes along its circumference. In particular, the radius of the brake body 3 – for example, the distance between the pivot axis of the brake body 3 and the contact contour 18 – increases along a first contact contour circumferential direction 33. For example, the contact contour circumferential direction 33 runs from the second side 32 to the first side 31 and / or opposite to the direction of rotation of the shaft 2.

[0067] As an example, a second contact section 27 adjoins the bearing section 24, in particular in the second direction opposite to the first direction along the body axis 22. The second contact section 27 serves to contact the brake section 14 in the braking state.

[0068] The second contact section 27 includes, by way of example, a second contact contour 28, which is in contact with the braking section 14 when braking. The contact contour 18 is, by way of example, oriented perpendicular to the body axis 22. The contact contour 18 has, by way of example, a curved, in particular convex, profile.

[0069] The brake body 3 expediently further comprises a first concave area 34 and a second concave area 35.

[0070] The first concave section 34 expediently represents the transition from the bearing section 24 to the first contact section 17, located on the first side 31. The second concave section 35 expediently represents the transition from the bearing section 24 to the second contact section 27, located on the second side 32.

[0071] As in the Figure 3As shown, in the release state the brake bodies 3 are expediently positioned with their first and second concave areas 34, 35 against the holding section 15.

[0072] Optionally, the brake body 3 further comprises a third concave section 44 and a fourth concave section 45. The third concave section 44 expediently represents the transition from the bearing section 24 to the first contact section 17, located on the second side 32. The fourth concave section 45 expediently represents the transition from the bearing section 24 to the second contact section 27, located on the first side 31.

[0073] The following section will describe shaft 2 in more detail: Shaft 2 advantageously has an axial section 36, which the brake elements 3 contact when braking. The axial section 36 is preferably cylindrical. The base of the axial section 36 preferably has the shape of a perfect circle. When braking, the brake elements 3 advantageously bear against the outer surface 37 of the axial section 36. The outer surface 37 of the axial section 36 advantageously has the shape of an (outer) cylindrical surface. The outer surface 37 of the axial section 36 advantageously has no projections and / or indentations. The outer surface of the axial section 36 is particularly flat and / or smooth.

[0074] The following section will discuss stop section 15 in more detail.

[0075] The retaining section 15 serves in particular to support the brake bodies 3 in the circumferential direction and / or to provide the pivotable mounting of the brake bodies 3.

[0076] The retaining section 15 is designed as a cage, in particular a freewheel cage. The retaining section 15 is in particular annular and / or cylindrical in shape and is expediently arranged coaxially to the shaft 2.

[0077] The retaining section 15 is advantageously arranged between the shaft 2 and the brake section 14, particularly in the radial direction. Advantageously, the retaining section 15 surrounds or engages the shaft 2. Advantageously, the retaining section 15 is arranged at a distance from the shaft 2.

[0078] Preferably, the holding section 15 is fixed to the braking section 14. In particular, the holding section 15 is mounted so as to be rotationally fixed relative to the braking section 14. The holding section 15 is especially mounted such that it does not rotate with the shaft 2.

[0079] The stopping section 15 comprises a plurality of stopping segments 38. For example, the number of stopping segments 38 is equal to the number of brake bodies 3. For the sake of clarity, the following are shown in the Figures 2 and 3 Only three of the 14 holding segments 38 shown are marked with the reference sign "38".

[0080] The retaining segments 38 are advantageously located on a circular path surrounding the shaft 2. For illustrative purposes, the retaining segments 38 are spaced apart from the shaft 2 and / or the brake section 14.

[0081] The retaining segments 38 each have the form of a ring section. Each retaining segment 38 is expediently arranged between two brake bodies 3. Each retaining segment 38 expediently extends from a bearing section 24 of a first brake body 3 to a bearing section 24 of a second brake body 3.

[0082] The following section will discuss update section 16 in more detail. An exemplary implementation of update section 16 is shown in the Figure 5 shown.

[0083] Actuation section 16 serves in particular to effect the movement of the brake bodies 3 from the release position to the braking position and / or from the braking position to the release position.

[0084] The actuating section 16 is advantageously arranged between the shaft 2 and the braking section 14, particularly in the radial direction. Preferably, the actuating section 16 is arranged between the shaft 2 and the holding section 15, particularly in the radial direction. Advantageously, the actuating section 16 revolves around or engages the shaft 2. Advantageously, the actuating section 16 is arranged at a distance from the shaft 2.

[0085] Preferably, the actuation section 16 is mounted so as to be movable, in particular rotatable, relative to the holding section 15 and / or relative to the braking section 14.

[0086] Advantageously, the actuating section 16 is rotatably mounted, in particular about an axis of rotation running parallel to the x-direction.

[0087] The actuating section 16 is preferably designed in an annular and / or circular cylindrical shape and is expediently arranged coaxially to the shaft 2. The actuating section 16 is expediently designed as an actuating ring.

[0088] The actuating section 16 expediently comprises a base section 39, which is preferably annular and oriented coaxially to the x-direction. The actuating section 16 preferably comprises a plurality of actuating projections 41, which expediently extend in the x-direction, particularly from the base section 39. For example, the number of actuating projections 41 is equal to the number of brake bodies 3. The actuating projections 41 are preferably designed as actuating pins. For the sake of clarity, the following are shown in the Figures 2 , 3 and 5 Only three actuation points 41 are marked with the reference sign "41".

[0089] The actuating projections 41 are advantageously located on a circular path around the shaft 2. For illustrative purposes, the actuating projections 41 are spaced apart from the shaft 2 and / or the brake section 14.

[0090] Each actuation projection 41 is expediently arranged between two brake bodies 3. In the release state, each actuation projection 41 expediently rests against a respective brake body 3.

[0091] As mentioned above, the actuating section 16 is mounted for rotational movement. The movement of the actuating section 16 shall also be referred to as the actuating movement. During the actuating movement, the actuating section 16 advantageously rotates only through an angle of less than 90 degrees, in particular less than 45 degrees or less than 30 degrees.

[0092] Actuating section 16 is expediently set into action by actuator unit 6.

[0093] The actuator unit 6 expediently includes an electric actuator to set the actuating section 16 into actuating motion. The actuator unit 6 expediently includes a solenoid and / or a piezoelectric unit to set the actuating section 16 into actuating motion. Alternatively or additionally, the actuator unit 6 includes a pneumatic cylinder to set the actuating section 16 into actuating motion.

[0094] Furthermore, the actuator unit 6 can comprise a differently designed actuator for setting the actuation section 16 into the actuation movement, in particular a piezoelectric actuator, an electromagnetic actuator, a shape memory alloy actuator (FGL actuator), an electroactive polymer actuator (EAP actuator), a magnetic shape memory actuator (MSN actuator), a pneumatic actuator, a hydraulic actuator, a pyro actuator, a mechanical actuator, an electrostrictive actuator and / or a thermal actuator.

[0095] The following section will discuss the braking state and the release state in more detail. First, let's look at the release status:

[0096] In the release state, there is no contact between the brake elements 3 and the rotating shaft 2. In the release state, a gap, in particular an air gap, exists between the brake elements 3 and the shaft 2, particularly in the radial direction (relative to the longitudinal axis of the shaft 2). In the release state, the brake elements 3 exert no braking force on the shaft 2 and / or the tool 1.

[0097] Each body axis 22 of the brake bodies 3 advantageously points in a different spatial direction. Advantageously, in the release state, each body axis 22 is pivoted relative to a radial direction (with respect to the shaft 2), in particular by the same angle.

[0098] For example, the brake bodies 3 are held in the release state by the actuating section 16. Each brake body 3 has an actuating projection 41, which holds the respective brake body 3 in the pivoted position. Each actuating projection 41 is advantageously located against the bearing section 24 and / or the first contact section 17 of a respective brake body 3.

[0099] Advantageously, in the release state there is no contact between rotating and stationary parts, so that in particular there is no loss torque.

[0100] The following section will discuss the condition of the brakes.

[0101] For example, the brake bodies 3 are in contact with the brake section 14 when braking.

[0102] The brake elements 3 are clamped between the brake section 14 and the shaft 2 in the braking state, particularly in the radial direction (relative to the longitudinal axis of the shaft 2). The brake elements 3 can also advantageously be referred to as clamping elements. In the braking state, the brake elements 3 advantageously connect the shaft 2 and the brake section 14 by means of a frictional connection. In particular, the brake elements 3 are each frictionally connected to the shaft 2 and the brake section 14 in the braking state.

[0103] In the braking state, the brake bodies 3 are each pivoted about their own pivot axis relative to the release state. Each axis 22 of the brake bodies 3 advantageously points in a different spatial direction. Advantageously, each axis 22 is aligned in a radial direction (with respect to the shaft 2).

[0104] The following section will explain in more detail how the brake bodies 3 are moved from the release position to the braking position.

[0105] The tool device 10 is designed to move the brake elements 3 from the release state to the braking state by pivoting them. Advantageously, all brake elements 3 are pivoted in the same direction of rotation. In particular, the direction of rotation is opposite to the direction of rotation of the shaft 2. Advantageously, the pivoting is inwards. In particular, the pivoting is about an axis parallel to the axis of rotation of the shaft. The ramp-shaped contour results in a change in the effective diameter of the brake elements. Advantageously, the tool device 10 is further designed to move the brake elements 3 from the braking state to the release state by pivoting them. Advantageously, the tool device 10 is designed to selectively establish or disengage the braking force coupling between the shaft 2 and the brake section 14 by pivoting the individual brake elements 3.

[0106] The actuating section 16 is expediently in contact with the brake bodies 3. The tool device 10 is preferably designed to set the actuating section 16 into an actuating movement in order to cause the brake bodies 3 to change from the release state to the braking state. The actuating movement is in particular a rotary movement of the actuating section 16.

[0107] Advantageously, the tool device 10 is designed to initiate the actuation movement of the actuation section 16 based on the detected emergency condition.

[0108] The pivoting of the brake elements 3 from the release state is expediently effected by the actuation movement of the actuation section. The actuation movement is, in particular, a movement of the actuation section 16 relative to the holding section 15 and / or relative to the braking section 14.

[0109] According to an exemplary embodiment, the brake bodies 3 are pre-tensioned. The pre-tensioning of the brake bodies 3 is advantageously achieved by means of springs, in particular by one or more spring elements (not shown in the figures). The actuating section 15 counteracts the pre-tensioning in the release state, in particular by positive locking, and thus prevents or blocks the pivoting movement of the brake bodies 3. In particular, the actuating section 15, exemplified by the actuating projections, is arranged in the respective pivot paths of the brake bodies 3, so that the brake bodies 3 cannot pivot in the direction of the braking state. The actuating movement of the actuating section 15 releases the blockage of the pivoting movement by the actuating section 15; exemplified by moving the actuating projections 41 out of the pivot paths of the brake bodies.The pivot paths required for pivoting the brake bodies 3 are released. Due to the preload of the brake bodies 3, they pivot. In particular, the first contact sections 17 pivot towards the shaft 2. For example, the pivoting occurs in a clockwise direction.

[0110] According to an alternative embodiment, the actuating section 16 serves to set the brake elements 3 into pivoting motion by pushing them, thus switching them from the release state to the braking state. Advantageously, the brake elements 3 are actively pivoted by the actuating section 16. In this alternative embodiment, the brake elements 3 are advantageously not pre-tensioned and / or not spring-loaded.

[0111] The braking device 12 is designed to be self-reinforcing, so that a movement of the shaft 2 is used to increase the braking effect of the brake elements 3 on the shaft 2 and / or to shorten the braking time.

[0112] The tool device 10 is designed to move the brake elements 3 from the release state to a guided state and from the guided state to the braking state during the braking process. The guided state is present, in particular, in a pivoting position of the brake elements 3 between the release state and the braking state. In the guided state, the brake elements 3 are moved along by a movement of the shaft 2, so that the change to the braking state is supported by the movement of the shaft 2.

[0113] The brake elements 3 are thus moved from the release state to the guided state. In the guided state, contact is established between the brake elements 3 and the shaft 2, in particular between the first contact sections 17 and the shaft 2. Due to this contact, the brake elements 3 are guided by the rotational movement of the shaft 2. Advantageously, in the guided state, the brake elements 3 are guided by the shaft 2 in the same direction in which they were moving before the guided state.

[0114] As an example, the brake elements 3 move from the release state initially in a first direction, for example, clockwise. During this movement, the brake elements 3, in particular the first contact sections 17, are guided towards the shaft 2 until they touch the shaft 2 and the following state is established. In the following state, the brake elements 3 are moved further in the first direction by the rotation of the shaft 2 until the brake elements 3 are in the braking state. For example, the shaft 2 rotates counterclockwise.

[0115] Preferably, the braking force exerted by the brake bodies 3 on the shaft 2 is greater in the braking state than in the following state.

[0116] As explained above, the contact contour 18 is ramp-shaped. During the pivoting of the brake body 3, the contact contour 18 advantageously rolls along the shaft 2. Due to the increasing radius of the contact contour, the brake element 3 is pressed ever more strongly against the shaft 2. In particular, during the pivoting motion, the brake element 3 is increasingly clamped or compressed between the shaft 2 and the brake section 14. This advantageously increases the braking force continuously.

[0117] The following describes an exemplary operation of the tool device 10.

[0118] Advantageously, the tool 1 is driven by the drive unit 5. The workpiece 11 is machined by the driven tool 1. During machining, contact occurs between the tool 1 and the user's body. The control unit 7 detects this contact as an emergency condition and then triggers the braking device 12. The actuator unit 6 moves the actuation section 16, thereby putting the brake elements 3 into the braking state, which in turn brakes the shaft 2 and the tool 1 until they come to a standstill. This braking occurs in less than 5 ms.

[0119] Advantageously, the brake elements 3 are returned to the release state, in particular by the actuator unit 6 and / or manual actuation. The tool 1 is again driven by the drive unit 5. The workpiece 11 or another workpiece is then machined by the tool 1. Advantageously, the tool 1 and / or the brake elements 3 are not exchanged between the braking of the tool 1 and / or the shaft 2 and the resumption of machining.

[0120] According to a preferred embodiment, the tool device 10 is configured to reset the brake elements 3 to the release state, in particular by means of the actuator unit 6 and / or a further actuator unit (not shown in the figures). Preferably, the tool device 10 is configured to reset the brake elements 3 to the release state in response to a reset command. The reset command is expediently entered into the tool device 10 by a user, for example via an input device, in particular a button.

[0121] Alternatively or additionally, the tool device 10 is designed such that the brake bodies 3 can be returned to the release state by manual actuation of the tool 1 and / or the shaft 2 and / or an operating element mechanically coupled to the shaft 2, for example a lever.

Claims

1. Tool apparatus (10) with a drivable tool (1), comprising a shaft (2) coupled to the tool (1), further comprising plural braking bodies (3), which are distributed around the shaft (2) in a circumferential direction (4), wherein the tool apparatus (10) is adapted to bring, in the course of a braking procedure, the plural braking bodies (3) from a release state into a braking state, wherein in the braking state the plural braking bodies (3) are in contact with the shaft and thereby exert a braking force upon the shaft (2), so that the shaft (2) and thereby also the tool (1) are braked and wherein in the release state the plural braking bodies (3) are not in contact with the shaft (2), characterized in that the tool apparatus is adapted to bring, in the course of the braking procedure, the plural braking bodies (3) from the release state into a carry-along state and from the carry-along state into the braking state, wherein the plural braking bodies (3) are carried along in the carry-along state by a movement of the shaft (2), so that the bringing of the plural braking bodies into the braking state is assisted by the movement of the shaft (2).

2. Tool apparatus (10) according to claim 1, wherein the tool apparatus (10) is adapted to bring the plural braking bodies (3) from the release state into the braking state by way of pivoting.

3. Tool apparatus (10) according to one of the preceding claims, wherein the plural braking bodies (3) each comprise a first contact section (17) with a ramp-shaped contact contour (18) which in the braking state is in contact with the shaft (2).

4. Tool apparatus (10) according to one of the preceding claims, wherein the tool apparatus (10) further comprises a braking section (14) which surrounds the shaft (2).

5. Tool apparatus (10) according to claim 4, wherein in the braking state the plural braking bodies (3) are clamped between the braking section (14) and the shaft (2).

6. Tool apparatus (10) according to one of the preceding claims, wherein the tool apparatus (10) comprises an actuation section (16), which is in contact or can be brought into contact with the plural braking bodies (3), and is adapted to carry out an actuation movement with the actuation section (16) to cause the plural braking bodies (3) being brought from the release state into the braking state.

7. Tool apparatus (10) according to one of the preceding claims, wherein the tool apparatus (10) is adapted to detect an emergency state and to activate the braking procedure on the basis of the detected emergency state.

8. Tool apparatus (10) according to claim 7, wherein the tool apparatus (10) is adapted to detect, as the emergency state, a contact between the tool (1) and the human body.

9. Tool apparatus (10) according to claim 7 or 8, wherein the tool apparatus (10) is adapted to detect a kickback as the emergency state.

10. Tool apparatus (10) according to one of the preceding claims, wherein the tool apparatus (10) is adapted to bring the tool (1) to a standstill within 10 ms or less, expediently 5 ms or less, by way of carrying out the braking procedure.

11. Tool apparatus (10) according to one of the preceding claims, wherein the tool apparatus (10) is adapted to bring the plural braking bodies (3) from the braking state back into the release state.

12. Tool apparatus (10) according to one of the preceding claims, wherein the tool apparatus (10) is adapted in such a manner that the one or plural braking bodies (3) can be brought from the braking state back into the release state by way of a manual actuation, in particular of the tool (1), the shaft (2) and / or an operating element coupled to the shaft (2).

13. Method for braking a tool (1) coupled to a shaft (2), comprising the step: bringing plural braking bodies (3), which are distributed around the shaft (2) in a circumferential direction (4), from a release state into a braking state, wherein in the release state the plural braking bodies (3) are not in contact with the shaft, in the braking state the plural braking bodies (3) are in contact with the shaft (2) and thereby exert a braking force upon the shaft (2), so that the shaft (2) and the tool (1) are braked, characterized in that the plural braking bodies (3) are brought from the release state into a carry-along state and from the carry-along state into the braking state and that, in the carry-along state, the braking bodies (3) are carried along by a movement of the shaft (2), so that the bringing of the plural braking bodies into the braking state is assisted by the movement of the shaft (2).

14. Method according to claim 13, wherein the method is carried out with a tool apparatus (10) according to one of the claims 1 to 12.