Tool holder

Abstract

The tool holder (10) serves to create the rotationally symmetrical frictional conditions between the collet chuck (1) and the collet chuck receiving body (17) so that tilting moments which may act on the central axis (M) of the collet chuck (1) during the clamping of the tool are minimized. This promotes the concentricity properties of the tool holder (10). The tool holder has a collet chuck receiving body (17) with a collet chuck receiving opening (15) and a collet chuck (1) inserted into the collet chuck receiving opening (15). A tool shaft (4) having a securing groove (6) can be inserted into the tool receiving opening (3). The clamping body (2) also has a wall portion (5) spanning the securing groove (6). During the clamping of the tool, a contact pressure (P) from the conical inner surface (18) of the collet chuck receiving opening (15) acts on the outer surface (19) of the clamping body (2) with at least two-fold rotational symmetry with respect to the central axis (M).

Description

Albrecht Präzision GmbH & Co. 17 August 2022 KG ALBR P010 WO pasc Antoniusstr. 25 Keyword: 73249 Wernau Concentricity optimization with compensation recess Tool holder

[0001] The invention relates to a tool holder for clamping tools, in particular for machining workpieces, with a collet which is preferably optimized with regard to the concentricity properties.

[0002] When machining workpieces, tools such as drills, milling cutters, and the like are typically used. These tools are held in a corresponding tool holder. The tool holder can, for example, have a sleeve-shaped collet into which the shank of a tool to be clamped can be inserted and clamped.

[0003] DE 102018 111 044 A1, for example, describes such a tool holder with a collet chuck. A clamping rotor is rotatably mounted in the tool holder and is configured to apply an axial force to the collet chuck. The clamping rotor has an internal thread that can be engaged with an external thread provided on a clamping pin of the collet chuck. Rotation of the clamping rotor results in an axial displacement of the collet chuck along a conical inner surface of the tool receiving opening of the tool holder.

[0004] In addition, the state of the art Pull-out protection devices are known, for example, from US Pat. No. 3,425,705, DE 202007 019 560 U1, and JP 2002-355727 A. During machining of a workpiece with a tool mounted in a toolholder, forces and / or torques acting on the tool can occur, which can cause the tool to gradually work its way out of the tool holder bore in the axial direction. Pull-out protection devices can counteract this axial pull-out of the tool from the toolholder.

[0005] The pull-out protection devices known from the prior art are generally based on a locking groove in the tool shank. The pull-out protection device in the collet has a locking pin that protrudes radially into the tool's locking groove, thus preventing axial removal of the tool from the collet. Such locking grooves are also referred to as Weldon grooves.

[0006] However, when clamping a tool with a locking groove in the tool shank in a conventional toolholder, the wall of the collet cannot support itself on the tool shank in the wall section of the collet that spans the locking groove of the tool shank, causing the wall of the collet to yield slightly inward toward the tool shank in this area. This influences the friction properties between the collet and the collet body of the toolholder in this area, while the friction properties of the rest of the collet remain unchanged. This can lead to elastic deformation of the collet in the longitudinal direction, particularly on one side, during clamping. of the tool, the central axis of the collet can tilt slightly out of the desired alignment central to the tool holder.

[0007] When clamping the tool into the toolholder, however, it is desirable that the collet with the tool clamped therein remains precisely aligned along the center axis of the toolholder, since an inclination of the tool relative to the center axis of the toolholder can have a negative impact on the tool's concentricity. In practice, during workpiece manufacturing, the tool or toolholder's concentricity requirements are sometimes micrometer-precise, so even seemingly slight inclinations of the axis can lead to a significant deterioration in the concentricity of the toolholder and thus of the tool clamped in it.

[0008] Based on this, it is the object of the invention to provide a tool holder with a collet which has improved concentricity properties after clamping a tool provided with a locking groove on the shank.

[0009] This object is achieved by the tool holder for clamping tools, in particular for machining workpieces, according to claim 1:

[0010] The tool holder according to the invention comprises a collet receiving body, a collet, and a clamping device. The collet receiving body is provided with a collet receiving opening having a conical inner surface, into which the collet is inserted. The collet has a clamping body which has a conical outer surface and a cylindrical tool receiving opening, which are arranged concentrically to one another around a central axis, wherein a tool shank having at least one locking groove can be inserted into the tool receiving opening, wherein the clamping body has a wall section spanning the at least one locking groove. The clamping device can be accommodated in the tool holder. The clamping device can, for example, be designed to pull the collet in the axial direction into the collet receiving opening of the collet receiving body. Alternatively, the clamping device can also be arranged outside the tool holder. In this case, the clamping device can, for example, be designed to press or push the collet in the axial direction into the collet receiving opening.In both cases, the collet for clamping tools can be subjected to an axial force by a clamping device. Due to the conical design of the inner surface of the collet receiving opening and the conical design of the outer surface of the clamping body, this force results in a contact pressure acting from the inner surface of the collet receiving opening onto the outer surface of the clamping body. The contact pressure acting when clamping the tool is (in a cross-sectional plane at the level of the locking groove) at least doubly rotationally symmetrical to the central axis. This can be achieved, for example, by the clamping body having a reduced wall thickness on a wall section that is (diametrically) opposite the wall section spanning the locking groove, compared to the wall thickness of the spanning wall section.It is preferred that at least one compensating recess is provided in the wall section of the clamping body on the diametrically opposite wall section. for example in the outer surface of the clamping body and / or the inner surface of the tool receiving opening of the clamping body.

[0011] This makes it possible to design the friction conditions between the collet and tool holder symmetrically. This means that the friction conditions between the collet and tool holder are at least essentially the same on both sides, which can reduce or prevent the center axis of the collet from tilting outwards in relation to the center axis of the tool holder. Due to the reduced wall thickness of the clamping body on the (diametrically) opposite side of the locking groove, the wall of the collet cannot rest on the tool shank on this side either, which means that the friction conditions are symmetrical on both sides. In addition, a (minor) elastic deformation of the collet on the opposite side of the locking groove can occur, which can compensate for the above-mentioned (minor) elastic deformation of the collet on the side of the locking groove.For example, the collet can deform in the axial direction in such a way that the wall of the collet tapers or bulges, depending on whether the clamping device is accommodated inside the tool holder and is designed to pull the collet axially into the collet receiving opening, or is arranged outside the tool holder and is designed to push or press the collet axially into the collet receiving opening.

[0012] A special feature of the tool holder according to the invention is that when clamping, the conical inner surface of the collet chuck opening is transferred to the The contact pressure acting on the outer surface of the clamping body is at least twofold rotationally symmetrical to the center axis of the collet, since the symmetrically acting contact pressure also creates a symmetrical frictional force between the collet and the collet holder body. The collet can also be designed, in particular, to distribute the contact pressure acting on it in a multifold rotationally symmetrical or point-symmetrical manner.

[0013] The clamping body can be interrupted, in particular, by slots or the like, at least in an upper region of the clamping body. A tool shank having a locking groove can be inserted into the tool receiving opening. The locking groove can be designed, for example, as a Weldon groove. The outer cone angle of the clamping body can be adapted, preferably aligned, to the inner cone angle of the collet receiving opening. The outer cone angle and / or the inner cone angle can, for example, have an angle between 0.5° and 15°, in particular between 1° and 10°, particularly preferably between 1.25 and 5°.

[0014] In particular, the opposite wall section is arranged at the same axial height as the wall section spanning the locking groove, preferably when the tool shank is (fully) inserted into the tool holder opening. As a result, the wall section with the reduced wall thickness is arranged axially opposite the wall section spanning the locking groove. This improves the symmetry of the friction conditions.

[0015] In a first embodiment, at least one (internal) A compensating recess is formed, whereby the wall thickness in this wall section is reduced and the contact pressure acts on the collet in a rotationally symmetrical manner. Additionally or alternatively, one or more (external) compensating recesses can be formed in the opposite wall section, so that the contact pressure acts on the collet in a rotationally symmetrical manner.

[0016] Preferably, the internal compensating recess is formed radially to the central axis in the inner surface of the tool receiving opening and / or the external compensating recess is formed radially to the central axis in the outer surface of the clamping body, whereby the wall thickness in this wall section is reduced.

[0017] It is preferred that the axial dimensions of the compensating recess correspond at least substantially to the axial dimensions of the locking groove of the tool shank, whereby the contact pressure is distributed rotationally symmetrically along the axial direction.

[0018] In particular, a plurality of first compensating recesses and / or second compensating recesses are formed in the opposite wall section, which are equidistant from one another and spaced from the wall section spanning the securing groove.

[0019] Alternatively, an annular (internal) compensating recess is formed in the clamping body on the inner surface of the tool receiving opening and / or an (external) compensating recess is formed on the outer surface of the clamping body, whereby the wall thickness of the clamping body is reduced in the area of ​​the compensating recess. If an (external) compensating recess is provided on the outer surface of the clamping body, mechanical contact between the clamping body of the collet and the collet holder body can be (completely) prevented in the axial area where the locking groove is located. This also leads to a symmetrical design of the friction conditions.

[0020] In particular, an angle covered by the compensation recess(es) corresponds to the circular arc angle of the wall section spanning the securing groove.

[0021] Preferably, the compensating recess is arranged diametrically opposite the wall section spanning the securing groove.

[0022] In particular, the radial depth of the compensating recess(es) is at least substantially constant along the circumference. The radial depth of the compensating recess is preferably significantly smaller than the depth of a shank groove in the tool shank. The radial depth can, for example, be in a range between 0.01 mm and 0.1 mm, i.e., in the tenth of a millimeter range.

[0023] In a second embodiment, a pull-out protection device with a securing recess is additionally formed in the clamping body, in which a securing element can be inserted and / or pushed in such a way that the securing element is arranged at least partially within the securing groove when the tool shank is arranged in the tool receiving opening, wherein at least one compensating recess is formed in the clamping body on the side of the clamping body opposite the pull-out protection device. The compensating recess allows the friction conditions and mass distributions of the two opposite sides to be brought closer together. Furthermore, an imbalance in the clamping body that would otherwise occur can be reduced or prevented.

[0024] It is preferred that the dimensions of the compensating recess correspond at least substantially to the dimensions of the securing recess.

[0025] Further details of advantageous developments or details of the invention can be found in the drawings, the description, and the dependent claims. They show:

[0026] Figure 1A is a schematic view of a collet according to an embodiment of the tool holder according to the invention,

[0027] Figure 1B is a schematic view of the collet according to a further embodiment of the tool holder according to the invention,

[0028] Figure 2 shows a longitudinal section of the collet with a tool shank inserted into the collet,

[0029] Figures 3A-3D show several different cross-sections along the cutting plane I through the collet in which the tool shank is inserted,

[0030] Figure 4 shows a detailed section of a tool holder in which a tool is clamped, in longitudinal section,

[0031] Figure 5 shows a cross-section of the tool holder from Figure 4 along the section plane II,

[0032] Figure 6 shows a detailed section of a tool holder with a collet chuck that has a pull-out protection, as well as

[0033] Figure 7 shows a detailed section of a tool holder with a collet chuck that has a pull-out protection.

[0034] Figure 1A shows a perspective view of a collet 1. The collet 1 has a clamping body 2 which extends along a central axis M of the collet 1. The clamping body 2 has a conical outer surface 19 and a cylindrical tool receiving opening 3. The conical outer surface 19 and the cylindrical tool receiving opening 3 are arranged concentrically to one another with respect to the central axis M. In the example shown in Figure 1, the clamping body 2 is interrupted by four slots 20. However, the clamping body 2 can also be interrupted by more or fewer slots 20. The slots 20 are spaced equidistant from one another. The clamping body 2 has a first end 26, towards which the tool receiving opening 3 is open. The tool receiving opening 3 has a cylindrical inner surface 21.The clamping body 2 is closed on the opposite side 27 and has there a clamping pin 22 provided with an external thread, with which a clamping device 16 can be engaged. The clamping device 16 is designed to apply an axial force F to the collet 1. The clamping device 16 can be accommodated in the tool holder 10 for this purpose. Alternatively, the clamping device 16 can also be accommodated without. the tool holder 10. In this case, the collet 1 does not have a clamping pin 22, but can be subjected to an axial force F by the clamping device 16 for clamping at the first end 26 of the clamping body 2.

[0035] In this example, the collet 1 has a pull-out protection device 11. A safety recess 12 is formed in the clamping body 2 for the pull-out protection device 11. On a side of the clamping body 2 diametrically opposite the safety recess 12, a compensating recess 14 is also formed in Figure 1A.

[0036] The collet 1 shown in Figure 1A also has a compensating recess 8 provided on the inner surface 21 of the tool receiving opening 3. The compensating recess 8 is formed in a wall section 7 of the clamping body 2, which is arranged opposite another wall section 5 that spans a locking groove 6 provided in a tool shank 4. In this example, the axial dimensions of the compensating recess 8 correspond to the axial dimensions of a locking groove 6 of a tool shank 4 that can be received in the tool receiving opening 3 of the collet 1. The length of a circular arc defined by the compensating recess 8 corresponds to the length of the circular arc of the other wall section 5.

[0037] Figure 1B shows another example of the collet 1 in perspective view. The collet 1 shown in Figure 1B differs from the collet 1 shown in Figure 1A in that the collet 1 does not have a pull-out protection 11. In addition, in the collet 1 shown in Figure 1B, a compensating recess 9 is formed in the outer surface 19 of the clamping body 2. The compensating recess 9 is annular in this example. The axial dimensions of the compensating recess 9 in the outer surface 19 of the clamping body correspond in this example to the axial dimensions of a locking groove 6 of a tool shank 5, which can be received in the tool receiving opening 3 of the collet 1.

[0038] Figure 2 shows a schematic longitudinal section of the collet 1 shown in Figure 1A. A tool shank 4 of a tool is inserted into the tool receiving opening 3 of the collet 1. The tool shank 4 has a locking groove 6, a so-called Weldon groove. The Weldon groove 6 is oriented towards the left in Figure 2, with the clamping body 2 having a wall section 5 spanning the Weldon groove 6. In a wall section 7, which is opposite the wall section 5 spanning the locking groove 6, a compensating recess 8 is formed in the inner surface 21 of the tool receiving opening 3. The compensating recess 8 is arranged at the same axial height Ha as the locking groove 6. Furthermore, the axial dimensions of the compensating recess 8 correspond to the axial dimensions of the locking groove 6.The wall thickness W of the clamping body 2 is greater in the wall section 5 than the wall thickness W in the wall section 7, which is opposite the wall section 5. .

[0039] Figure 3A shows the cross-section corresponding to Figure 2 along the section axis I. The circular arc angle covered by the compensating recess 8 relative to the central axis M corresponds in Figure 3a to the circular arc angle of the wall section spanning the securing groove 6. 5. In Figure 3A, the compensating recess 8 is arranged diametrically opposite the wall section 5 spanning the securing groove 6.

[0040] Figure 3B shows an alternative example of a collet chuck 1 in cross-section. In the example shown in Figure 3B, two compensating recesses 8 are formed in the inner surface 21 of the tool receiving opening 3. The two compensating recesses 8 are arranged equidistant from one another and from the wall section 5 spanning the securing groove 6. It is also possible for several additional compensating recesses 8 to be provided in the inner surface 21 of the tool receiving opening 3.

[0041] Figure 3C shows a further example of a collet chuck 1 in cross-section. In this example, the compensating recess is annular, meaning that in the area of ​​the compensating recess 8, the tool shank 4 is not in contact with the wall of the clamping body 2.

[0042] Figure 3D shows another example of a clamping body 2 in which the compensating recess 9 is formed on the outer surface 19 of the clamping body 2. In this example, no contact pressure acts on the clamping body 2 from the inner surface of the collet receiving opening 15 when clamping the tool in the area of ​​the compensating recess 9. In the remaining area of ​​the outer surface 19 of the clamping body 2, a rotationally symmetrical contact pressure acts on the clamping body 2 from the conical inner surface 18 of the collet receiving opening 15.

[0043] Figure 4 shows a schematic detail a longitudinal section of the tool holder 10 according to the invention during clamping of a tool. The clamping body 2 has a compensating recess 8 in Figure 4. During clamping of the tool, the clamping device 16 applies an axial force F to the collet 1, whereby the collet 1 moves along the conical inner surface 18 of the collet receiving opening 15. The clamping device 16 can be arranged inside the tool holder 10, as shown in Figure 6, or alternatively outside the tool holder 10. Due to the downwardly tapered inner surface 18 of the collet receiving opening 15, a contact pressure P acts from the collet receiving body 17 onto the clamping body 2 of the collet. In Figure 4, the distribution of the contact pressure P is illustrated by arrows.Thus, the contact pressure P on the side where the locking groove 6 of the tool shank 4 is located corresponds at least substantially to the contact pressure P on the side where the compensating recess 8 is located. This results in the friction conditions between the clamping body 2 and the collet holder body 17 being at least approximate to one another on both sides. Due to the at least twofold rotationally symmetrical friction conditions, there is no tilting of the central axis M of the collet 1 when the tool is clamped.

[0044] Figure 5 shows a schematic cross-section of the collet 1 from Figure 4 along the section plane II. The cross-section can be divided into four quadrants Q1 to Q4, wherein the locking groove 6 of the tool shank 4 is arranged in the first quadrant Q1. In the quadrant Q3 opposite the first quadrant Q1, the contact pressure P from the collet holder body 17 is The clamping body 2 is adapted to the contact pressure P in the first quadrant Q1. The second quadrant Q2 and the fourth quadrant Q4 are arranged laterally to the first quadrant Q1 and between the third quadrant Q3. The contact pressure P acting in the second quadrant Q2 and the fourth quadrant Q4 also correspond, at least substantially, to one another.

[0045] Figure 6 shows a detailed section of the tool holder 10 in longitudinal section when a tool is clamped. In this exemplary embodiment, the collet has a pull-out protection device 11. The pull-out protection device 11 has a securing recess 12 which extends at least partially radially to the central axis M of the collet 1. In the example shown in Figure 6, the securing recess 12 is additionally inclined axially to the central axis M. The angle of inclination of the securing recess 12 is preferably adapted to the Weldon groove 6 formed in the tool shank 4. The angle of inclination can be between 20° and 70°, preferably between 30° and 60° to a horizontal plane. In the example shown, the angle of inclination is approximately 45° to the horizontal plane. A securing element 13 is arranged in the securing recess 12, which in the inserted state is at least partially arranged in the Weldon groove 6 of the tool shank 4.The securing element 13 can be pin-shaped. The securing element 13 prevents the tool shank 4 from gradually working its way axially out of the tool receiving opening 3 of the collet 1 during use of the tool holder 10, for example due to vibrations. On the diametrically opposite side of the pull-out protection 11, the collet 1 can have a Compensation recess 14, the dimensions of which at least substantially correspond to the dimensions of the securing recess 12. The compensation recess 14 can be designed and arranged mirror-symmetrically to the securing recess 12.

[0046] In order to make the frictional relationship between the collet 1 and the collet chuck body 17 rotationally symmetrical, the clamping body 2 has a compensating recess 8 on the inner surface 21 of the tool receiving opening 3. As already described above, the clamping body 2 can also be provided with an external compensating recess 9 formed in the outer surface 19 of the clamping body 2.

[0047] Figure 7 illustrates another example of a tool holder 10, wherein the collet 1 in this example has a tangential pull-out protection 11. In this example, the securing recess 12 is formed tangentially to the Weldon groove 6 in the clamping body 2, so that an overlap space is formed between the Weldon groove 6 and the securing recess 12. A securing element 13 can be inserted into the securing recess 12 so that the securing element 13 can be at least partially located in the securing recess 12 and the overlap space when the securing element 13 is inserted into the securing recess 12. The securing element 13 can, for example, be pin-shaped.In this example, the collet 1 can also have a compensating recess 14 on the diametrically opposite side of the pull-out protection 11, the dimensions of which correspond at least substantially to the dimensions of the safety recess 12. The compensating recess 14 can. be designed and arranged mirror-symmetrically to the securing recess 12.

[0048] The tool holder 10 according to the invention serves to create rotationally symmetrical friction conditions between the collet 1 and the collet receiving body 17 so that tilting moments that can act on the central axis M of the collet 1 when clamping the tool are minimized. This promotes the concentricity properties of the tool holder 10. The tool holder has a collet receiving body 17 with a collet receiving opening 15 having a conical inner surface and a collet 1 with a clamping body 2 inserted into the collet receiving opening 15. The clamping body 2 contains a conical outer surface 19 and a cylindrical tool receiving opening 3 that defines a central axis M and is arranged concentrically to the outer surface. A tool shank 4 having at least one locking groove 6 can be inserted into the tool receiving opening 3.The clamping body 2 also has a wall section 5 spanning the at least one locking groove 6. The collet 1 can be subjected to an axial force F by a clamping device 16 for clamping tools. When clamping the tool, a contact pressure P acts from the conical inner surface 18 of the collet receiving opening 15 onto the outer surface 19 of the clamping body 2 with at least twofold rotational symmetry to the central axis M. Reference symbols: 1 Collet 2 Clamping body 3 Tool holder opening 4 Tool shank 5 Wall section that spans the locking groove 6 Locking groove of the tool shank 7 Opposite wall section 8 (internal) compensation recess 9 (external) compensation recess 10 Tool holder 11 Pull-out protection 12 Retaining recess 13 Retaining element 14 Compensation recess 15 Collet holder opening 16 Clamping device 17 Collet holder body 18 Conical inner surface of the collet holder opening 19 Conical outer surface of the clamping body 20 Slots in the clamping body 21 Cylindrical inner surface of the tool holder opening 22 Clamping pin 23 Side wall sections of the clamping body 24 Collet wall 25 Clamping rotor 26 First end of the clamping body 27 Second end of the clamping body M Center axis of the collet P Contact pressure when clamping Q1-Q4 quadrants U circumferential direction W Wall thickness of the clamping body I, II Cutting planes

Claims

AMENDED CLAIMS received by the International Bureau on 31 January 2024 (31.01.2024) 1. Tool holder (10) for clamping a tool provided with a locking groove on the shaft, in particular for machining workpieces, comprising: - Tool with at least one locking groove (6), in particular a Weldon groove, having a tool shaft (4); - a collet chuck body (17) with a collet chuck opening (15) having a conical inner surface (18); and - a collet (1) inserted into the collet receiving opening (15) with a clamping body (2) which has a conical outer surface (19) and a cylindrical Tool receiving opening (3) which are arranged concentrically around a central axis (M), wherein the tool shank (4) having at least one securing groove (6) is inserted into the tool receiving opening (3) and the clamping body (2) has a wall section (5) spanning the at least one securing groove (6); wherein the collet (1) for clamping tools is clamped by a clamping device (16) with an axial force (F); wherein during clamping a contact pressure (P) from the conical inner surface (18) of the collet receiving opening (15) acts on the outer surface (19) of the clamping body (2) at least twofold rotationally symmetrical to the central axis (M).

2. Tool holder (10) according to claim 1, characterized in that the clamping body (2) is secured to a 24 AMENDED SHEET (ARTICLE 19) securing groove (6) spanning wall section (5) opposite wall section (7) a reduced wall thickness (W).

3. Tool holder (10) according to claim 1 or 2, characterized in that the opposite wall section (7) is arranged at an axial height (Ha) with the wall section (5) spanning the securing groove (6).

4. Tool holder (10) according to one of the preceding Sayings, characterized in that at least one internal compensating recess (8) is formed in the opposite wall section (7).

5. Tool holder (10) according to one of the preceding claims, characterized in that at least one external compensating recess (9) is formed in the opposite wall section (7).

6. Tool holder (10) according to claim 4 or 5, characterized in that the inner compensating recess (8) is formed radially to the central axis (M) in an inner surface (21) of the tool receiving opening (3) and / or the outer compensating recess is formed radially to the central axis (M) in an outer surface (19) of the clamping body (2).

7. Tool holder (10) according to one of claims 4 to 6, characterized in that the axial dimensions of the compensating recess (8, 9) correspond at least substantially to the axial dimensions of the securing groove (6) of the tool shank (4). 25 AMENDED SHEET (ARTICLE 19) 8 . Tool holder (10) according to one of the preceding Sayings, characterized in that in the opposite wall section (7) on the inner surface (21) of the tool receiving opening (3) a plurality of internal compensating recesses (8) and / or external compensating recesses (9) are formed which are equidistant from one another and spaced apart from the wall section (5) spanning the securing groove (6).

9. Tool holder (10) according to one of claims 1 to 7, characterized in that in the clamping body (2) an annular internal compensating recess (8) is formed.

10. Tool holder (10) according to one of claims 1 to 7, characterized in that in the clamping body (2) an annular external compensating recess (9) is trained.

11. Tool holder (10) according to one of claims 1 to 8, characterized in that one of the Compensation recesses (8, 9) covered angle, the Circular arc angle of the wall section (5) spanning the securing groove (6).

12. Tool holder (10) according to one of claims 4 to 7, characterized in that the compensating recess (8, 9) is arranged diametrically opposite the wall section (5) spanning the securing groove (6).

13. Tool holder (10) according to one of claims 4 to 26 AMENDED SHEET (ARTICLE 19) 12, characterized in that a radial depth of the Compensation recesses (8, 9) are at least substantially constant along the circumference.

14. Tool holder (10) according to one of the preceding claims, characterized in that a pull-out safety device (11) with a securing recess (12) is formed in the clamping body (2), in which a securing element (13) can be inserted and / or pushed in such a way that the securing element (13) is arranged at least partially within the securing groove (6) when the tool shank (4) is arranged in the tool receiving opening (3), wherein on the side of the clamping body (2) opposite the pull-out safety device (9) clamping body (2) at least one compensation recess (14) is formed into the clamping body (2).

15. Tool holder (10) according to claim 14, characterized in that the dimensions of the compensating recess (14) correspond at least substantially to the dimensions of the securing recess (11). 27 AMENDED SHEET (ARTICLE 19)

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