Cutting tool

Abstract

The invention relates to a cutting tool (1), comprising a shaft (100) and a cutting head (4), a closed cutting head plane surface (20) of which rests on a closed shaft end plane surface (10) of the shaft (100) and which is partly inserted through the closed shaft end plane surface (10) into a shaft recess (11) of the shaft (100), wherein the shaft recess (11) is circumferentially surrounded by a shaft inner face (12) of the shaft (100); the shaft inner face (12) has a plurality of shaft driver flanks (13) and intermediate inner lateral surfaces (14) in an alternating arrangement, the intermediate inner lateral surfaces connecting the shaft driver flanks (13) together; the cutting head (4) has a cutting head outer face (22) which is inserted into the shaft recess (11) and has a plurality of cutting head driver flanks (23) acting laterally on the shaft driver flanks (13) such that a rotation of the cutting head (4) relative to the shaft (100) is blocked; the intermediate inner lateral surfaces (14), in the region of the cutting head driver flanks (23), are each continuously adjacent to a free space (31) to the cutting head outer face (22); and the cutting head (4) has a centering region (26) which is plugged into the shaft (100) in order to center same.

Description

[0001] 1150 WO, September 4, 2025

[0002] 1

[0003] Cutting tool

[0004] The present invention relates to a cutting tool.

[0005] EP 2 958 693 Al describes a milling tool consisting of a tool shank and a cutting head attached to its end face. The milling tool described

[0006] 5. The torque is transferred from the tool shaft to the cutting head by means of a clamping connection, which is also intended to center the cutting head.

[0007] This clamping connection introduces significant radial forces into the shank. These radial forces act perpendicular to the longitudinal axis of the tool shank and lead to elastic or even plastic deformation. This deformation alters the original

[0008] 10. Precise positioning of the cutting head on the shank and thus its centering to the shank is impaired. As a result, the cutting head can no longer rest exactly on the shank, leading to reduced stability and accuracy of the milling tool.

[0009] This issue is particularly significant in high-precision machining operations, such as reaming, where tolerances in the micrometer range must be maintained. Inaccurate support of the cutting head can lead to vibrations, uneven cuts, and an overall poorer surface finish on the machined workpieces. Furthermore, the increased shank load caused by radial forces can lead to premature wear of the milling tool, especially a reaming tool, and a reduced service life.

[0010] 20 The object of the present invention is to provide a cutting tool in which the cutting head rests more precisely on the shank by means of improved torque transmission from the shank to the cutting head, thereby improving the quality of the machining operation and extending the service life.

[0011] The object of the present invention is solved by the subject matter of claim 1. Advantageous embodiments of the invention can be found in the dependent claims, which are freely combinable with one another.

[0012] The cutting tool comprises a shank and a cutting head, which rests on a closed shank end face of the shank with a closed cutting head end face and extends through the closed shank end face into a shank recess of the

[0013] 30 shafts are partially inserted, with the shaft recess facing from an inner side of the shaft.

[0014] Public 1150 WO, September 4, 2025

[0015] 2

[0016] The shaft is completely surrounded, the inside of the shaft having several shaft drive flanks and alternating intermediate inner surfaces connecting the shaft drive flanks, the cutting head having a cutting head outer surface inserted into the shaft recess with several cutting head drive flanks, which

[0017] 5 laterally against the shaft drive flanks in such a way that a relative rotation of the cutting head to the shaft about a central axis of rotation of the shaft is blocked, wherein the intermediate inner surfaces at the level of the cutting head drive flanks each continuously border a free space to the outside of the cutting head, wherein the cutting head has a centering area inserted into the shaft in a centering manner.

[0018] 10. The term "flank" in "shank drive flanks" and "cutting head drive flanks" refers to a lateral surface in the sense of the surfaces that mesh with each other in a gear tooth. A person skilled in the art can therefore clearly identify the "shank drive flanks" and "cutting head drive flanks" by touch.

[0019] "At the level of the cutting head driver flanks" means that something, in particular an area of ​​the shaft, is located in the axial extent of the cutting head driver flanks along the central axis of rotation of the shaft.

[0020] Because the intermediate inner surfaces at the level of the cutting head drive flanks are continuously adjacent to a clearance to the outer side of the cutting head, the cutting head and the inner side of the shank only touch at the level of the cutting head drive flanks.

[0021] 20 directly, where the cutting head drive flanks laterally abut the shank drive flanks. Since radial reaction forces can therefore only occur at the level of the cutting head drive flanks where the shank drive flanks and the cutting head drive flanks laterally contact each other due to their mutual abutment, the radial force flow at the level of the torque connection formed by the shank drive flanks and cutting head drive flanks is reduced to practically non-existent, which results in correspondingly less or no deformation of the shank and thus better preservation of the shape and dimensions of the closed shank end face.

[0022] By aligning the cutting head drive flanks laterally against the shank drive flanks

[0023] 30, so that the relative rotation of the cutting head to the shaft around the central axis of rotation of the shaft is locked, a torque connection is created between the inside of the shaft.

[0024] Public 1150 WO, September 4, 2025

[0025] 3 and the cutting head, so that the shank, under a rotation with respect to the central axis of rotation of the shank, in which the shank drive flanks rotate leading around the central axis of rotation of the shank and the cutting head drive flanks rotate lagging around the central axis of rotation of the shank, transmits its torque to the cutting head and

[0026] 5. This is thus set into a cutting head rotation with respect to the central axis of rotation of the shaft.

[0027] Since the cutting head driver flanks strike the shank driver flanks laterally, the reaction forces associated with the torque on the cutting head driver flanks and shank driver flanks are at least partially tangential to the circular path centered on the central axis of rotation of the cutting circle.

[0028] 10. If the cutting head drive flanks and shank drive flanks are designed to extend radially and axially, the radial force flow into the inside of the shank is effectively zero, or zero when considering a parallelogram of forces only. Because the intermediate inner surfaces at the level of the cutting head drive flanks are continuously adjacent to a clearance to the outside of the cutting head, no radial force flow occurs from the cutting head at the level of the cutting head drive flanks and outside of the cutting head drive flanks to the inside of the shank.

[0029] By ensuring that the intermediate inner surfaces at the level of the cutting head drive flanks continuously border a clearance to the outer side of the cutting head, several are fully enclosed by the lateral stops of the shank drive flanks against the

[0030] 20 cutting head driver flanks formed closed free spaces between the outer surface of the cutting head and the inner surface of the shank, each extending continuously along one of the intermediate inner surfaces.

[0031] The cutting head drive flanks are typically formed as flat surfaces on the outside of the cutting head. The shank drive flanks are typically formed as flat surfaces on the inside of the shank.

[0032] By having the intermediate inner surfaces at the level of the cutting head driver flanks continuously border a clearance to the outer side of the cutting head, the cutting head driver flanks strike the shank driver flanks laterally outside the intermediate inner surfaces, i.e. without contacting the intermediate inner surfaces.

[0033] 30 This means that the cutting head drive flanks do not touch the intermediate inner surfaces, but only bear laterally against the shank drive flanks. Therefore

[0034] Public 1150 WO, September 4, 2025

[0035] 4 ensures precise and controlled power transmission without involving the intermediate inner surfaces in the contact between the shaft drive flanks and cutting head drive flanks.

[0036] The closed end face of the shaft is perpendicular to the central axis of rotation of the shaft.

[0037] 5 extending in a plane and, because it is closed, thus free of steps; the closed shank end face can therefore be completely circumferentially circumferentially at a constant axial height level with respect to the central axis of rotation of the shank. The closed cutting head face extends perpendicularly to the central axis of rotation of the shank in the plane in which the closed shank end face is perpendicular

[0038] The cutting head surface extends 10 towards the central axis of rotation, so that it rests on the closed shank end face, forming a flat contact surface. The closed shank end face borders the shank recess, meaning that the closed shank end face is open on the inside.

[0039] By having a centering area inserted centrally into the shank, the cutting head is centered with respect to the central axis of rotation of the shank, so that in the cutting tool the centering of the cutting head is outside the area of ​​the torque connection realized by the cutting head driver flanks and shank driver flanks and in the axial direction along the central axis of rotation of the shank away from the closed shank end face and the closed cutting head face.

[0040] 20 is realized. The centering of the cutting head is therefore structurally independent of the flat contact of the closed cutting head surface on the closed shank end face, whereby the cutting head drive flanks are typically formed and arranged in the axial direction along the central axis of rotation of the shank between the centering area of ​​the cutting head and the closed cutting head surface. The shank has a centering area corresponding to the centering area of ​​the cutting head, which centers the centering area of ​​the cutting head with respect to the central axis of rotation of the shank.

[0041] Typically, the centering area of ​​the cutting head is designed with a continuous outer cone shape and is surrounded by a corresponding continuous inner cone shape.

[0042] 30 Centering area of ​​the shaft recorded.

[0043] The spaces are usually filled with air.

[0044] Public 1150 WO, September 4, 2025

[0045] 5

[0046] The cutting head can be manufactured monolithically from sintered cemented carbide. Sintered cemented carbide is a composite material consisting of a sintered skeletal structure made of hard particles, usually metal carbides such as tungsten carbide, and a [missing information] in the spaces between the skeletal structure.

[0047] 5. The cutting head is made of a metal-based alloy, usually a cobalt-based alloy. Monolithic means that the cutting edges form a single unit with the rest of the cutting head. However, it is also conceivable and possible for the cutting head to be made of a different material, for example, steel, and / or to be multi-part, for example, consisting of a base body with reversibly detachable or metallurgically bonded cutting elements.

[0048] 10. The shaft is usually made of steel. Steel is more ductile than sintered carbide.

[0049] The number of cutting head drive flanks that laterally engage the shank drive flanks is typically three. This ensures a more even and stable power transmission compared to two such engagement cutting head drive flanks, thus improving the efficiency and accuracy of machining operations. However, it is also conceivable and possible for the number of cutting head drive flanks that laterally engage the shank drive flanks to be more than three.

[0050] The shaft can be made of one piece or multiple pieces. If the shaft is made of multiple pieces, the inner side of the shaft can be shaped like a sleeve.

[0051] The shank component can be a monolithic section that rests on an end face of another shank component, either reversibly detachably or materially bonded to it. If the shank is thus multi-part, an optional internal coolant channel system of the cutting tool can be designed more flexibly.

[0052] The shank is typically made of a more ductile material than the cutting head drive flanks, at least in the area of ​​the intermediate inner surfaces. This choice of material allows for simpler shank manufacturing, while the dimensional stability of the closed shank end face is effectively maintained because the radial force flow is reduced by corresponding radial reaction forces between the cutting head and the shank at the level of the shank drive flanks and the

[0053] The torque flow formed by the 30 cutting head drive flanks is low to practically non-existent.

[0054] Public 1150 WO, September 4, 2025

[0055] If a dimension of 6 is present, the shank deforms correspondingly less or not at all. This contributes to the durability and precision of the cutting tool.

[0056] According to a further development of the cutting tool, the outer surface of the cutting head alternately features connecting surfaces with the cutting head drive flanks.

[0057] Five intermediate outer surfaces are present, each bordering one of the clearances. This causes the shank drive flanks to contact completely outside the intermediate outer surfaces and thus only against the cutting head drive flanks. Consequently, radial reaction forces occur only at these specific contact areas between the cutting head drive flanks and the shank drive flanks.

[0058] 10 the radial force flow is reduced to the level of the torque flow formed by the cutting head drive flanks.

[0059] According to a further development of the cutting tool, the cutting head drive flanks, which laterally abut against the shank drive flanks, and these shank drive flanks are each designed to extend radially and axially with respect to the central axis of rotation of the shank. This reduces to zero any radial forces that can be introduced into the shank drive flanks by the cutting head drive flanks in the area of ​​their mutual lateral contact, according to a parallelogram of forces.

[0060] According to a further development of the cutting tool, the shank drive flanks and the cutting head drive flanks are arranged circumferentially in such a way that the clearances are filled by a

[0061] The cutting head and shaft are continuously connected in a manner that prevents the relative rotation of the cutting head to the shaft around the shaft's central axis of rotation in the opposite direction to the relative rotation of the shaft. This means that during assembly, the cutting head, when partially inserted into the shaft recess, can be rotated relative to the shaft in such a way that the relative rotation of the cutting head to the shaft around the shaft's central axis of rotation is locked. This creates a rotational stop that prevents the cutting head from rotating further. However, within a certain angular range, the cutting head can be rotated out of this rotational stop, allowing for flexible and precise assembly.

[0062] According to a further development of the cutting tool, the cutting head has several friction edges. These friction edges are specifically designed to ensure the cutting head...

[0063] to utilize 30 reaming operations. Reaming is a machining operation in which the volume of material removed per revolution of the cutting head is relatively small.

[0064] Public 1150 WO, September 4, 2025

[0065] 7

[0066] This method makes it possible to achieve a very high surface quality, which is particularly important when precise and smooth surfaces are required. Typically, the reaming edges taper axially away from one end face of the cutting head.

[0067] According to a further development of the cutting tool, the cutting head can be reversibly detached.

[0068] 5 connected to the shank. This means that the cutting head is screwed to the shank, for example, by one or more screws that extend axially along the central axis of rotation of the shank through the cutting head, which increases the stability and precision of the cutting tool during use.

[0069] According to a further development of the cutting tool, the cutting head drive flanks are axially spaced away from the closed end face of the shank at an arbitrary point. This "axially floating" arrangement results in a continuous, closed gap around the central axis of rotation of the shank. This gap is connected to the clearances that extend continuously along the inner surfaces. This design enables precise and controlled machining.

[0070] 15. Transmission of torque from the shank to the cutting head is enabled. This is because the corresponding axially lower sides of the cutting head drive flanks, which face away from the closed shank end face, are arranged in a frictionless manner relative to the shank in the axial direction away from the closed shank end face. This arrangement minimizes friction and ensures efficient power transmission, which allows the

[0071] 20 Increased performance and service life of the cutting tool.

[0072] According to a further development of the cutting tool, the centering area of ​​the cutting head features a continuous externally conical centering surface. This continuous externally conical centering surface of the cutting head enables precise alignment of the cutting head with the central axis of rotation of the shank, thus increasing the precision of machining operations with the cutting tool. The conical shape securely and stably holds the cutting head in the shank, minimizing vibrations and movement during machining. The conical shape ensures an even distribution of forces. "Externally conical" describes a shape that follows a cone and, when inserted into the shank recess, extends axially along the central axis of rotation.

[0073] The shank tapers away from the closed end face of the shank at a distance of 30°. Consequently, the shank has a continuous, externally conical centering surface for the cutting head.

[0074] Public 1150 WO, September 4, 2025

[0075] 8 corresponding continuous internal cone-shaped centering surface, which centers the continuous external cone-shaped centering surface of the cutting head with respect to the central axis of rotation of the shaft.

[0076] According to a further development of the cutting tool, the cutting head has a polygonal shape.

[0077] 5. A release recess for unscrewing the cutting head is created by a frictional engagement with the shank in the area of ​​the cutting head's centering region. This frictional engagement is formed between the cutting head's centering region and the area that centers the cutting head's centering region with respect to the shank's central axis of rotation. The polygonal release recess is typically shaped like an internal hexagon.

[0078] The tool is designed so that a corresponding hexagonal tool can be inserted into the polygonal unlocking recess and rotated about the central axis of rotation of the shank, thus applying a rotational impulse to the cutting head and thereby improving the release of the frictional connection. However, a multi-sided polygonal shape for the unlocking recess, deviating from an internal hexagon, is also conceivable and possible, for example, an internal triangular, internal square, internal pentagonal, etc.

[0079] Further advantages and expediencies of the invention will become apparent from the following description of an exemplary embodiment with reference to the accompanying figures.

[0080] The figures show

[0081] Fig. 1: a perspective view of a [missing word] along a central axis of rotation

[0082] 20 extended cutting tools;

[0083] Fig. 2: a side view of the cutting tool

[0084] Cutting tool;

[0085] Fig. 3: a representation of the cutting tool in the direction of a view towards an end face of the

[0086] Cutting tool;

[0087] 25 Fig. 4: a perspective view of a front shaft component of the

[0088] Cutting tool;

[0089] Fig. 5: a representation of the front shaft component in the direction of a view towards an end face;

[0090] Fig. 6: a representation of the front shaft component in a side view;

[0091] Fig. 7: a perspective view of a cutting head of the machining tool;

[0092] Public 1150 WO, September 4, 2025

[0093] 9

[0094] Fig. 8: a representation of the cutting head in the direction of view towards a closed

[0095] Cutting head flat surface;

[0096] Fig. 9: a representation of the cutting head in a side view;

[0097] Fig. 10: a representation of the cutting head in the direction of a view towards an end face;

[0098] 5 Fig. 11: a cross-sectional view of the cutting tool without hatching according to the section lines XX in Fig. 2;

[0099] Fig. 12: a longitudinal section view of the cutting tool according to the section lines X1-X1 in Fig. 3.

[0100] Figures 1 and 2 show a cutting tool 1 in perspective and side view respectively.

[0101] 10 The cutting tool 1 comprises a shank 100 with a front shank component 2 and a rear shank component 3, which are metallurgically bonded to each other. The front shank component 2 and the rear shank component 3 are each made of steel.

[0102] The machining tool 1 further comprises a cutting head 4, which is monolithically manufactured from sintered carbide.

[0103] 15 The cutting head 4 is centered with respect to the central axis of rotation 5 of the front shank component 2. The front shank component 2 is also centered with respect to the rear shank component 3, so that the central axis of rotation 5 of the front shank component 2 forms a common central axis of rotation of the cutting tool 1. The cutting tool 1 is designed to be rotatably driven for performing a cutting operation.

[0104] 20 The front shaft component 2 has two diametrically opposed flattens 6, which makes it easier to rotate the front shaft component 2 relative to the cutting head 4 during assembly and disassembly.

[0105] Fig. 3 shows the cutting tool 1 viewed parallel to the central axis of rotation 5 towards an end face 7 of the cutting head 4. In Fig. 3 it is particularly easy to see that the

[0106] The end face 7 is reversibly connected to the front shaft component 2 by a screw 8 in the axial direction and concentrically with respect to the central axis of rotation 5. The screw 8 is surrounded by several coolant outlets 9 of the cutting head 4, from which coolant can escape from the end face 7.

[0107] Public 1150 WO, September 4, 2025

[0108] 10

[0109] Fig. 4 shows the front shaft component 2 in a perspective view. The front shaft component 2 is sleeve-shaped and has a closed shaft end face 10 that surrounds the central axis of rotation 5 in a ring-like manner and completely borders a shaft recess 11 on its end face. The shaft end face 10 extends perpendicular to the central axis of rotation 5.

[0110] The axis of rotation 5 is planar. In the assembled state according to Fig. 1, the cutting head 4 rests on the shank end face 10 and is partially inserted into the shank recess 11. This allows the cutting head 4 to cut outside the front shank component 2 and, within the shank recess 11, is torque-locked, centered, and reversibly detachable from the front shank component 2.

[0111] The shaft recess 11 is completely surrounded by an inner shaft surface 12 of the front shaft component 2. The inner shaft surface 12 has three shaft drive flanks 13, which are evenly distributed with respect to the central axis of rotation 5 and each extend axially and radially. In Fig. 4, one of these shaft drive flanks 13 is visible in planar detail. The shaft drive flanks 13 alternate circumferentially with

[0112] 15 intermediate inner surfaces 14 of the inner side 12 of the shaft are connected, such that during a revolution around the central axis of rotation 5, each shaft driver flank 13 is followed without gaps by an intermediate inner surface 14 and vice versa. The shaft driver flanks 13 are each provided with a chamfered surface 13a on the side of the shaft end face 10. Likewise, the intermediate inner surfaces 14 are each provided with a chamfered surface 13a on the side of the shaft end face 10.

[0113] 20 of a chamfered surface 14a provided.

[0114] Fig. 5 shows the front shank component 4 viewed parallel to the central axis of rotation 5, looking at the shank end face 10. Fig. 5 clearly shows that the shank drive flanks 13 are arranged leading along the central axis of rotation 5 with respect to the direction of rotation 15 and can therefore be rotated relative to the cutting head 4. Also clearly visible in Fig. 5 are the grooved areas 16 on the inner surface 12 of the shank, which are each part of the intermediate inner surfaces 14. These grooved areas 16 reduce the risk of collision between the cutting head 4 and the front shank component 2 during axial insertion along the central axis of rotation 5. An internal thread 17 is provided axially below the intermediate inner surfaces 14 in the front shank component 2.

[0115] 30, which interacts with screw 8 shown in Fig. 3. In addition, Fig. 5

[0116] Public 1150 WO, September 4, 2025

[0117] 11 four extensively distributed coolant channels 18 of the front shaft component 2 are recognizable, which are fluidly connected to the coolant outlets 9 shown in Fig. 3.

[0118] Fig. 6 shows a side view of the front shaft component 2, which has a continuous externally conical end region 19 that leads to

[0119] 5 Coolant line formed, which is discussed in more detail with reference to Fig. 12.

[0120] Fig. 7 shows a perspective view of the cutting head 4. Fig. 7 shows that the cutting head 4 has a closed cutting head planar surface 20, with which the cutting head 4 rests on the closed shank end face 10, forming a flat bearing surface. The closed cutting head planar surface 20 is perpendicular to the central

[0121] The cutting head 4 is designed to extend along the axis of rotation 5. The closed cutting head face 20 is connected to an axial projection 21 of the cutting head 4. In the assembled state of the cutting tool 1, as shown in Fig. 1, the axial projection 21 is inserted into the shank recess 11. The axial projection 21 has an outer surface 22 of the cutting head, which has three cutting head driver flanks 23 extending axially and radially to the central axis of rotation 5. The cutting head driver flanks 23 are arranged at the same angular distance from the central axis of rotation 5 to the shank driver flanks 13.

[0122] In the assembled state of the cutting tool 1 according to Fig. 1, the cutting head drive flanks 23 abut laterally against the shank drive flanks 13, so that a relative rotation of the cutting head 4 to the front shank component 2 and thus to the

[0123] The shaft 100 is locked around the central axis of rotation 5. Between the cutting head drive flanks 23, the outer surface 22 of the cutting head has an intermediate outer surface 24, through which the cutting head drive flanks 23 are connected to each other. The intermediate outer surfaces 24 are arranged alternately with the cutting head drive flanks 23.

[0124] The axial projection 21 has a base surface 25 axially opposite the closed cutting head face 20 in the area of ​​the cutting head drive flanks 23 and intermediate outer side surfaces 24. In the assembled state of the cutting tool 1 according to Fig. 1, the base surface 25 is axially spaced from the front shank component 2, so that the base surface 25 as well as the

[0125] 30 Cutting head driver flanks 23 and intermediate outer side surfaces 24 in axial direction

[0126] Public 1150 WO, September 4, 2025

[0127] 12 are arranged opposite the closed cutting head plan surface 20 and thus the shaft end face surface 10 without friction to the front shaft component 2.

[0128] The axial projection 21 further features an externally conical centering area 26 with a continuous externally conical surface 26a, which serves to center the cutting head 4

[0129] 5 is inserted into the front shank component 2 with respect to the central axis of rotation 5 in the assembled state of the cutting tool 1 as shown in Fig. 1. The axial projection 21 has a hexagonal and thus polygonal unlocking recess 27 for unscrewing the cutting head 4 from a frictional engagement formed with the front shank component 2 in the area of ​​the centering region 26. A hexagonal tool can thus be inserted into the unlocking recess 27.

[0130] 10, so that the cutting head 4 can be subjected to a rotational impulse by a rotation of the hexagonal tool with respect to the central axis of rotation 5, so that the frictional connection can be more easily released.

[0131] In Fig. 7 it can also be seen that the cutting head 4 has six axially extending and radially tapering friction cutting edges 28 that taper away from the end face 7 of the cutting head 4.

[0132] Fig. 8 shows a view of the cutting head 4 parallel to the central axis of rotation 5 on the cutting head surface 20. Fig. 8 shows the direction of rotation 29 in which the cutting head 4 must be rotated parallel to the central axis of rotation 5 on the cutting head surface 20, according to the selected viewing direction, so that the friction cutting edges

[0133] 20 28 cut by rotating the shaft drive flanks 13 in the direction of rotation 29.

[0134] Fig. 9 shows a side view of the cutting head 4. In Fig. 9 it is particularly easy to see that the axial projection 21 protrudes from the cutting head planar surface 20.

[0135] Fig. 10 shows the cutting head 4 analogous to its representation in Fig. 3, but without the screw 8. Fig. 10 shows that the cutting head 4 has bearing surfaces 30 for the screw 8,

[0136] 25 which are arranged alternately with the coolant outlets 9. The coolant outlets 9 are formed as recesses in the end face 7 of the cutting head 4 and are covered by the screw 8.

[0137] Fig. 11 shows a cross-section of the cutting tool 1 along the section line XX from Fig. 2. For clarity, no hatching is shown.

[0138] Figure 11 shows particularly well that the intermediate inner side surfaces 14 are at the level of the

[0139] Public 1150 WO, September 4, 2025

[0140] 13

[0141] The cutting head drive flanks 23 each abut a continuous clearance 31 to the outer surface 22 of the cutting head in the area of ​​the intermediate outer surface 24. This allows the outer surface 22 of the cutting head to be spaced from the intermediate inner surface 14 in any radial direction 32 with respect to the central axis of rotation 5.

[0142] 5 The clearances 31 extend continuously between the shaft drive flanks 13 and the cutting head drive flanks 23 and are isolated from each other circumferentially by the lateral stops of the cutting head drive flanks 23 against the shaft drive flanks 13. Due to the clearances 31, the cutting head 4 does not transmit any radial forces to the front shaft component 2 in the area of ​​the intermediate outer surfaces 24, while

[0143] 10. The cutting head drive flanks 23 abut laterally against the shank drive flanks 13. Due to the radial and axial extent of the cutting head drive flanks 23 and the shank drive flanks 13, virtually no radial forces are transmitted into the front shank component 2 by their mutual lateral abutment.

[0144] Figure 11 further shows that the intermediate outer surfaces 24 each border continuously on one of the clearances 31. Thus, each clearance 31 is bounded in the radial direction 32 with respect to the central axis of rotation 5 by one of the intermediate outer surfaces 24 and one of the intermediate inner surfaces 14, except for the areas where the cutting head drive flanks 23 laterally abut the shank drive flanks 13. In these areas, the clearances 31 are defined by the lateral contact of the

[0145] 20 shaft drive flanks 13 limited by the cutting head drive flanks 23.

[0146] Figure 11 further shows that the shaft drive flanks 13 and the cutting head drive flanks 23 are arranged such that the clearances 31 can be connected to each other by rotating the cutting head 4 in the direction of rotation 33 about the central axis of rotation 5 relative to the front shaft component 2, without the intermediate inner surfaces 14 coming into contact with the intermediate outer surfaces 24. This is possible when the screw 8 is loosened. In this loosened state, the cutting head 4 can be rotated in the opposite direction of rotation 34 relative to the front shaft component 2 until the cutting head drive flanks 23 abut laterally against the shaft drive flanks 13 again, as shown in Figure 11. This creates a

[0147] 30 further relative rotation of the front shaft component 2 to the cutting head 4 around the central

[0148] Public 1150 WO, September 4, 2025

[0149] 14

[0150] Rotation axis 5 is locked, whereby the intermediate inner side surfaces 14 are rotated without contact relative to the intermediate outer side surfaces 24.

[0151] In Fig. 12, the cutting tool 1 is shown in a longitudinal section along section line XI I -XI I from Fig. 3. Fig. 12 shows that the centering area 26 is equipped with a

[0152] The cutting head 4 is centered on a correspondingly shaped, continuous, internally conical centering area 35 of the front shaft component 2 via a continuous, externally conical surface 26a, thus centering the cutting head 4 outside the cutting head drive flanks 23 and outside the closed shaft end face 10. Figure 12 further shows that a central channel 37 of the rear shaft component 3 is fluidly connected to the other channels 18 in the area of ​​the front shaft component 2. These other channels 18 are fluidly connected to channels 38 formed by the screw 8 and the cutting head 4, and through these channels to the coolant outlets 9. The externally conical end region 19 deflects the coolant into the other channels 18. Figure 12 clearly shows that

[0153] 15 the cutting head driver flanks 23 are arranged in the axial direction along the central axis of rotation 5 between the centering area 26 of the cutting head 4 and the shaft end face 10 shown in Fig. 4.

[0154] The front shaft component 2 rests on an end face 39 of the rear shaft component 3 and is materially bonded to it at this point.

[0155] 20 Figures 1 to 12 show a cutting tool 1 in which the cutting head 4 rests particularly precisely on the shank end face 10 because the intermediate inner side surfaces 14 each border continuously on a clearance 31, so that a transmission of radial forces to the front shank component 2 by a torque transmission from the front shank component 2 to the cutting head 4 can only occur where the cutting head driver flanks 23 laterally abut the shank driver flanks 13.

[0156] The coolant channel system of the cutting tool 1 described with reference to Fig. 12 is optional. The number of cutting head driver flanks 13 can be greater than three. The radial and axial extent of the cutting head driver flanks 23 and

[0157] 30 shaft drive flanks 13 is advantageous because radial reaction force components are effectively reduced to zero even in the area of ​​their mutual contact, so that

[0158] Public 1150 WO, September 4, 2025

[0159] 15 Accordingly, mainly tangential reaction forces are responsible for transmitting the torque from the front shaft component 2 to the cutting head 4. However, it is conceivable and also possible to deviate from such a radial and axial extension. The shaft 100 can, as shown, for example, in Figs. 1, 2 and 12,

[0160] The stock may be formed in multiple parts, consisting of the front stock component 2 and the rear stock component 3. However, it is also conceivable and possible that the stock 100 is formed in one piece.

[0161] The cutting tool 1 is designed as a reaming tool because such a tool requires a precisely aligned cutting head 4. However, it is also conceivable and possible for the cutting tool 1 to be designed for a different machining operation, such as milling or drilling, by modifying the design of the reaming edges 28 accordingly, so that they become milling or drilling edges, respectively. Naturally, the number of these edges can also be changed. Thus, it is also conceivable and possible to change the number of reaming edges 28.

[0162] Public

Claims

1150 WO, September 4, 2025 16 REQUIREMENTS 1. Cutting tool (1) comprising a shank (100) and a cutting head (4) which rests on a closed shank end face (10) of the shank (100) with a closed cutting head face (20) and is partially inserted through the closed shank end face (10) into a shank recess (11) of the shank (100), wherein the shank recess (11) is circumferentially surrounded by an inner shank surface (12) of the shank (100), wherein the inner shank surface (12) has several shank drive flanks (13) and, alternating with the shank drive flanks (13), intermediate inner surfaces (14) connecting them to one another, wherein the cutting head (4) has a cutting head outer surface (22) inserted into the shank recess (11) with several cutting head drive flanks (23) exhibits, which laterally strike against the shaft drive flanks (13),that a relative rotation of the cutting head (4) to the shaft (100) about a central axis of rotation (5) of the shaft (100) is blocked, wherein the intermediate inner surfaces (14) at the level of the cutting head drive flanks (23) each continuously adjoin a clearance (31) to the outer surface (22) of the cutting head, wherein the cutting head (4) has a centering area (26) inserted centrally into the shaft (100).

2. Cutting tool (1) according to claim 1, wherein the outer surface of the cutting head (22) has, alternating with the cutting head driver flanks (23), intermediate outer surfaces (24) connecting them to each other, each of which is continuously adjacent to one of the clearances (31).

3. Cutting tool (1) according to one of the preceding claims, wherein the cutting head driver flanks (23) which laterally abut against the shank driver flanks (13), and these shank driver flanks (13) are each designed to extend radially and axially with respect to the central axis of rotation (5) of the shank (100). 1150 WO, September 4, 2025 17 4. Cutting tool (1) according to one of the preceding claims, wherein the shank drive flanks (13) and the cutting head drive flanks (23) are arranged circumferentially such that the clearances (31) are continuously connected to each other by a relative rotation of the cutting head (4) to the shank (100) about the central axis of rotation (5) of the shank (100) in the opposite direction to the relative rotation.

5. Cutting tool (1) according to one of the preceding claims, wherein the cutting head (4) has several friction cutting edges (28).

6. Cutting tool (1) according to one of the preceding claims, wherein the cutting head (4) is reversibly detachable from the shank (100).

7. Cutting tool (1) according to one of the preceding claims, wherein the cutting head driver flanks (23) are axially spaced away from the closed shank end face (10) at any point from the shank (100).

8. Cutting tool (1) according to one of the preceding claims, wherein the centering area (26) of the cutting head (4) has a continuously externally conical centering surface (26a).

9. Cutting tool (1) according to one of the preceding claims, wherein the cutting head (4) has a polygonal unlocking recess (27) for unscrewing the cutting head (4) from a frictional engagement formed with the shank (100) in the area of ​​the centering area (26) of the cutting head (4).

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