Base for accommodating a chisel holder
Patent Information
- Application Number
- AU2025269459
- Authority / Receiving Office
- AU · AU
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-06-25
- Filing Date
- 2025-04-30
- Publication Date
- 2026-10-29
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
If the pick holder comprises lateral contact surfaces matching the clamping surfaces of the bottom part, wherein these lateral contact surfaces come into contact with the clamping surfaces, at least in the event of an overload, a type of elastic spring system is formed. In the event of an overload, the lateral contact surfaces move the clamping surfaces outward, such that the applied force is absorbed by the spring action. If the angle between the clamping surfaces is set to a value from 66° to 76°, this results in good transfer of force, particularly in road-milling applications, and prevents the pick holder from becoming jammed in the rear overload-support area of the bottom part in the event of an overload. Preferably, the clamping surfaces are designed, at least in part, as flat surfaces to achieve a defined transfer of force. However, it is also conceivable that the clamping surfaces could be contoured, for instance, curved, to suit the desired application. According to a variant of the invention, provision may be made for the rear overloadsupport area to comprise a securing surface disposed between the two clamping surfaces. Forces can also be transferred through the securing surface in the event of an overload. In particular, in the event of an overload, either the clamping surfaces or the securing surface may initially come into contact with the pick holder. If the overload condition is particularly severe, either the securing surface or the clamping surfaces are then brought into contact to provide additional support. To prevent stress peaks in the bottom part, provision may be made for the securing surface to be transitioned, either directly or indirectly, laterally into the clamping surfaces via rounding transitions and / or flat transition surfaces (chamfers). This also reduces the risk of the pick holder becoming jammed in the rear overload-support area of the bottom part. One possible variant of the invention may be such that the two clamping surfaces each form an angle with the securing surface, wherein these two angles are preferably equal. Preferably, the respective angle between the clamping surfaces and the securing surface is selected to be in the range from 40° to 68°. This angle range is particularly well-suited for ground-working machines used in road construction. For road-milling machines and stabilizers, an angle range between 45° and 62.5° is preferred. An angle range particularly suitable for road-milling machines is between 52° and 57°. One possible variant of the invention may be such that the plug-in mount has an insertion extension in the area of the top of the base body, which widens the crosssection of the plug-in mount in the direction from the underside of the base body toward the top of the base body and radially outward, and such that the clamping surfaces and / or the securing surface are disposed at least sectionally inside the insertion extension and delimit it at least sectionally. The insertion extension can be used to accommodate a shank widening of the pick holder, wherein the shank widening is disposed in the area of the plug-in attachment of the pick holder. In this way, the crosssection of the plug-in attachment can be reinforced in this particularly vulnerable transition area. In addition, this area, where the pick holder has been reinforced, can now be effectively utilized to safely transfer the resulting stresses from the pick holder to the bottom part in the event of an overload. The shank widening of the pick holder may widen the cross-section of its plug-in attachment, at least sectionally, at the transition to the rear transfer surfaces. In addition or alternatively, provision may be made for the shank widening to widen the cross-section of the plug-in attachment, at least sectionally, at the transition to the lateral inclined surfaces of the pick holder. In addition or alternatively, provision may be made for the shank widening to widen the cross-section of the plug-in attachment, at least sectionally, at the transition to the two front transfer surfaces of the pick holder. If provision is made for the insertion extension to have lateral sections that extend adjacent to the two clamping surfaces laterally to the base body and that extend from the rear side of the base body toward the front side, then recessed receiving sections of the insertion extension are also formed in the area of the sides of the bottom part, in which the material thickenings of the shank widening of the pick holder can be accommodated. This significantly improves the lateral stability of the tool system, in particular in the event of an overload. In the context of the invention, the insertion extension may in particular extend circumferentially around the plug-in mount. According to a variant of the invention, provision may be made for the rear support surface to merge into a front support surface on both sides of the base body via a respective setback recessed into the base body, which setback is preferably formed as a rounding transition, or for the rear support surfaces on either side of the base body to each merge into a front support surface via a setback recessed into the base body, which is preferably formed as a rounding transition. This creates the distinct front and rear support surfaces, which result in improved functionality during operation. In particular, the setback creates a take-up space. The pick holder can settle further into this take-up space as the support surfaces wear down. If, in addition, provision is made, in the area of the setbacks, for a respective clamping surface of the rear overloadsupport area to be disposed at least sectionally, then the rear overload-support area can be integrated into the bottom part in a space-saving manner. Furthermore, the setback in the clamping surface creates a material weakness that enhances the deformability of the clamping surface in the event of an overload, thereby contributing to a more effective force dissipation. A particularly preferred variant of the invention is such that at least one front shanksupport surface of a front shank contact is provided in the plug-in mount and facing the underside of the base body, and such that the front shank-support surface is disposed on the side of the plug-in mount opposite the rear overload-support area. The front shank-support surface can be used to securely support the plug-in attachment of the pick holder in the plug-in mount, while the pick holder simultaneously rests with its transfer surfaces against the support surfaces of the holder mount of the bottom part. In this case, a pressure screw, located at the rear, for instance, can act on the plug-in attachment, securing the pick holder to the bottom part. In the event of an overload, a support span is created in the direction of the longitudinal extent of the plug-in attachment through the spacing of the front shank-support surface and the rear overload-support area. In the event of an overload, this support span allows for the effective dissipation of bending stresses acting on the plug-in attachment. Preferably provision may be made for the front shank-support surface to be divided into two sub-surfaces by means of a depression formed in the base body. Preferably, a form-fit element can be inserted into the depression to secure the pick holder against rotation relative to the bottom part in the circumferential direction of the shank mount. According to a particularly preferred variant of the invention provision may be made for the front shank-support surface to comprise a partial-cylinder surface of a hollow cylinder, and for the cylinder axis of this hollow cylinder to form a clamping angle in the range from 5° to 15°, preferably in the range from 9° to 12° with the clamping surfaces of the overload-support area and / or the overload-contact surface of the overload support area. The clamping angle ensures a form-fit clamping of the pick holder in the bottom part in the event of an overload, against the front shank-support surface on one side and the rear overload-support area on the other. This form-fit clamping prevents the plug-in attachment from shifting inside the plug-in mount in the event of an overload. This prevents or limits undefined deformation states that could result in undue stress and, consequently, damage to the bottom part. A bottom part according to the invention may, for instance, be characterized in that the two front support surfaces are separated from each other at the front by means of a setback, wherein preferably provision is made for the setback to be disposed opposite the overload-support area. It is also conceivable that the rear support surfaces are separated from each other by a transition section recessed into the base body, and that the transition section is disposed in the area of the rear overload-support area. This separation of the rear support surfaces from at least some areas of the overload-support areas results in improved functionality. In particular, material deformations that occur during operation in the area of the rear support surfaces, the clamping surfaces, and / or the securing surface do not impair the functionality of the adjacent functional components or functional surfaces. Thus, in particular, provision may also be made for the transition section to comprise a surface area set back relative to the rear support surfaces, which merges, at least partially, into the clamping surfaces and / or into the securing surface. As the above explanations illustrate, rear support surfaces may be disposed on both sides adjacent to the transition section. These may be flush with each other or form an angle with each other, in particular an obtuse angle. The problem of the invention is also solved by a tool combination having a bottom part according to any of claims 1 to 13 and a pick holder, wherein the pick holder is inserted into the plug-in mount of the bottom part via a plug-in attachment, and the pick holder is supported by its transfer surfaces against the support surfaces of the bottom part, and wherein the pick holder has a rear shank contact having lateral contact surfaces that face the clamping surfaces. The invention is explained in greater detail below based on an exemplary embodiment shown in the figures. In the Figures: Figure 1 shows a side view of a tool system having a bottom part and a pick holder, Figure 2 shows a rear perspective view of the tool system of Figure 1, Figure 3 shows a side view of the tool system of Figures 1 and 2, viewed from the side opposite to Figure 1, Figure 4 shows a perspective front view of the tool system of Figures 1 to 3, Figure 5 shows a perspective front view of a pick holder, Figure 6 shows a perspective side view of the pick holder of Figure 5 in conjunction with a pressure screw, Figure 7 shows a perspective view from below of the pick holder of Figures 5 and 6, Figure 8 shows a sectional representation of the pick holder of Figures 5 to 7, Figure 9 shows a longitudinal section of the pick holder of Figures 5 to 8 along its central longitudinal plane, Figure 10 shows a perspective side view of the bottom part of the tool system of Figures 1 to 4, Figure 11 shows a perspective rear view of the bottom part of Figure 10, Figure 12 shows a longitudinal section of the tool system of Figures 1 to 4, Figure 13 shows the tool system of Figures 1 to 4 along the section line XIII - XIII of Figure 3, Figure 14 shows a bottom view of the pick holder of Figures 5 to 9 as a further illustration, Figure 15 shows a section along the section line marked XV-XV in Figure 6, which extends perpendicular to the longitudinal plug-in attachment axis. Figure 1 shows a tool system having a bottom part 10 and a pick holder 30 attached thereto. The bottom part 10 has a connection side 11, which can have a, preferably concave, curved connection surface. This connection side 11 can be used to place the bottom part 10 on the convex outer surface of the (not shown) milling drum tube and the bottom part 10 can be suitably attached thereto, for instance by means of a welded connection. Provision may be made for the bottom part 10 to have lateral clearances 12 in the transition area to the connection side 11. These clearances 12 can be used to hold welding material to form a tack weld. The base body 13 of the bottom part 10 forms the bottom connection side 11. This base body 13 has an anterior front side 13.1 in the feed direction V and a posterior rear side 13.2 in the feed direction V. The bottom part 10 is delimited by lateral surfaces at the sides. The feed direction V extends from left to right in Figure 1. This feed direction V results from the intended use of the pick holder 30 or the tool system. Provision may be made for at least one shoulder 13.3 to be present in the area of at least one of the lateral surfaces to form a material diverting area. Figure 10 shows that the bottom part 10 can have a holder mount 14. The holder mount 14 has front support surfaces 15.1, 15.2, which are disposed at least sectionally in front of a plug-in mount 18. The plug-in mount 18 can be inserted as a penetration or as a depression in the base body 13 of the bottom part 10. Preferably, a setback 15.3 is disposed between the two front support surfaces 15.1, 15.2 in the area in front of the plug-in mount 18. The two front support surfaces 15.1, 15.2 are disposed at an angle to each other, as can be seen in particular in Figure 11. This angle opens towards the top of the bottom part 10. The bottom part 10 may also have at least one rear support surface 16.1, 16.2 in its area facing the rear side 13.2. In this exemplary embodiment, two rear support surfaces 16.1, 16.2 are used. The rear support surfaces 16.1, 16.2 are flush with each other such that they are disposed on one plane. However, it is also conceivable that the two rear support surfaces 16.1, 16.2 are at an angle to each other, wherein they preferably form an obtuse angle. The two rear support surfaces 16.1, 16.2 are each formed by support sections 19.3. To this end, the support sections 19.3 may form parts of a protrusion 19.2. Preferably, the two protrusions 19.2, which each form a support section 19.3, are disposed spaced apart from each other and transverse to the feed direction V. Figure 10 illustrates that the two rear support surfaces 16.1, 16.2 can also be interconnected by a transition section 16.3. The transition section 16.3 may then also be used to create a support for the pick holder 30. As shown in Figure 10, one front support surface 15.1, 15.2 each merges into respective rear support surfaces 16.1, 16.2 on both sides of the bottom part 10. Advantageously, there are setbacks 17 between the front support surfaces 15.1, 15.2 and the assigned rear support surfaces 16.1, 16.2, which setbacks can be groove-like. The front support surfaces 15.1, 15.2 are thus spatially separated from the rear support surfaces 16.1, 16.2 to form defined support areas. Figure 10 shows that the plug-in mount 18 can be equipped with an insertion extension 18.1 at its upper end. This insertion extension is used to facilitate the insertion of a plug-in attachment 44 of the pick holder 30 (see Figure 5). An overload-support area 18.4 can be provided in the area of the plug-in mount 18. This overload-support area 18.4 preferably has two clamping surfaces 18.5, 18.6, which are disposed at an angle to each other. The two laterally disposed clamping surfaces 18.5, 18.6 may be interconnected by means of a securing surface 18.7. The securing surface 18.7 also extends at an angle to the clamping surfaces 18.5, 18.6. Preferably, each clamping surface 18.5, 18.6 forms the same angle with the securing surface 18.7, which is preferably obtuse. If the pick holder 30 is installed, at least a subset of the functional surfaces and functional sections of the bottom part 10, in particular the clamping surfaces 18.5, 18.6, the front support surfaces 15.1, 15.2, the rear support surfaces 16.1, 16.2, the insertion extension 18.1 and / or the shank-support surface 18.2 explained below can be disposed symmetrically with respect to a central longitudinal plane ME of the pick holder 30. Preferably, the overload-support area 18.4 and its clamping surfaces 18.5 and 18.6 and the securing surface 18.7 is formed by the insertion extension 18.1 or is disposed in the area of the insertion extension 18.1 to implement a compact design. Figures 10 and 11 further show that a front shank-support surface 18.2 facing the front side 13.1 is formed inside the plug-in mount 18. The front shank-support surface 18.2 may be interrupted by a depression 18.3, such that partial surfaces of the front shanksupport surface 18.2 are formed on both sides of the depression 18.3. The depression 18.3 can be groove-like in particular. The depression 18.3 may extend from the underside, in particular from the connection side 11, of the base body 13 in the direction of the longitudinal extent of the plug-in mount 18. A molded body (not shown), in particular a clamping sleeve, or a dowel pin or the like, can be accommodated in the depression 18.3. The molded body extends partially into the area of the plug-in mount 18. This can be seen more clearly in Fig. 12. At the rear, a screw mount 19 is inserted into the base body 13 of the bottom part 10. A fastening screw, in particular a pressure screw 20, can be screwed into the screw mount 19, as shown in Figure 12. Preferably, access to the screw mount 19 is protected in the area between the two protrusions 19.2 (see Figure 2). The screw mount 19 may be inserted into a surface section 19.1 that extends in a transverse manner between the two protrusions 19.2. The protrusions 19.2 are delimited by boundary surfaces 19.4 facing the screw mount 19. This is shown in Figure 11. The screw mount 19 opens into the area of the plug-in mount 18 of the base body 13, as illustrated in Figure 12. Preferably, the base body 13 has a recess 19.5, shown in Figure 12, adjacent to the opening area of the screw mount 19. The recess 19.5 forms a receiving area that is set back to the rear of the plug-in mount 18. This receiving area facilitates inserting the pick holder 30 into the plug-in mount 18. As illustrated in Fig. 10, the plug-in mount 18 may, in the insertion direction, that is, in the direction of the longitudinal extent of the plug-in mount 18 from top to bottom, have, immediately or indirectly behind the insertion extension 18.1, a hollow cylinder section 18.8 that extends, at least sectionally, circumferentially. It is possible that screw mount 19 opens into the plug-in mount 18 at the rear. The front shank-support surface 18.2 is preferably disposed in the plug-in mount 19, opposite the opening area of the screw mount 19. The hollow cylinder section 18.8 is positioned between the insertion extension 18.1 and the opening area of the screw mount 19 and / or between the front shank-support surface(s) 18.2 and the insertion extension 18.1 in the insertion direction. Figures 5 to 8 illustrate the design of the pick holder 30. As these illustrations shown in, the pick holder 30 has a support body 35. As will be described below, the support body 35 has a pick mount 32 having a central longitudinal axis M at the machining side and a plug-in attachment 44 having a longitudinal plug-in attachment axis 44.2 at an opposite plug-in attachment side. As shown in the exemplary embodiment, the central longitudinal plane ME of the pick holder 30 can be defined by the central longitudinal axis M and the plug-in attachment axis 44.2. A support section 33, which is preferably shaped like a protrusion or can have a protrusion, is integrally formed on the support body 35 in the area of one machining side. The support section 33 at least partially forms the pick mount 32. Preferably, the pick mount 32 is designed as a bore and has the central longitudinal axis M. The central longitudinal axis M of the pick mount 32 is clearly visible in the longitudinal section shown in Figure 9. Alternatively, a cutting tip MS can also be provided, in particular directly or indirectly attached, to the support body 35 on the machining side. This is shown symbolically in Figure 6 as an alternative, indicated by a dashed line. At its free end, the support section 33 forms a bearing surface 31, which preferably extends radially to the central longitudinal axis M of the pick mount 32. The bearing surface 31 is particularly preferably circumferential. The bearing surface 31 is used to support a wear protection disk of a round pick (not shown). The pick shank of such a round pick is inserted into the pick mount 32 of the pick holder 30. The wear protection disk is disposed between the bearing surface 31 and a head of the round pick and can be freely rotated about the central longitudinal axis M of the pick mount 32. A centering protrusion 31.1 may be formed in the area of the bearing surface 31. This centering protrusion 31.1 can, for instance, be designed as a circumferential bulge. The centering protrusion 31.1 is used to center the wear protection disc described above on the bearing surface 31. For this purpose, provision may be made for the wear protection disk to have a circumferential groove on the underside, at its end facing the bearing surface 31. The centering protrusion 31.1 engages with this circumferential groove, while the underside of the wear protection disc rests on the bearing surface 31. The support section 33 can be formed having one or more wear marks 33.1. If several wear marks 33.1 are used, these are preferably disposed spaced apart from one another in the direction of the central longitudinal axis M of the pick mount 32, as Figure 5 shows. The wear marks 33.1 can, for instance, be designed as at least partially circumferential grooves. This is also shown in Figure 5. A transition section 34 is used to connect the support section 33 to the support body 35. Preferably, the transition section 34 widens the support section 33 in the direction of the support body 35, at least sectionally. The support body 35 may have an apron 35.1 at the front, which is disposed at least sectionally in front of the support section 33. The apron 35.1 can be equipped with indentations 35.2 to enable improved material transport in favor of better wear resistance of the pick holder 30. For improved rigidity, stiffening struts 35.3 may be used to couple the support section 33 to the support body 35. The stiffening struts 35.3 can extend to both sides and / or in the area of the rear side of the support section 33, as shown in Figures 4 and 6. The pick holder 30 is delimited by lateral surfaces 35.4 in the area of its sides, which extend from its front side to its rear side. The lateral surfaces 35.4 can preferably have front slopes 35.5 to taper the apron 35.1 in the front area like an arrow. This results in improved material diverting during operation. At the front, the support body 35 has a front piece 35.6, which preferably delimits the apron 35.1 at the front. Figure 7 shows that the pick holder 30 may have an ejector mount 36 at the rear. The ejector mount 36 preferably has two functions. On the one hand, the ejector mount 36 is used to hold an ejector tool, which is used to gain access to the pick mount 32. The ejector tool can then be used to eject a pick held in the pick mount 32 in the direction of the central longitudinal axis M of the pick mount 32. The second function of the ejector mount 36 is to eject overburden material that has worked its way into the area of the pick mount 32 during operation. This overburden material is conveyed radially outwards through the ejector mount 36. As Figure 7 further illustrates the ejector mount 36 is delimited by two lateral surfaces 36.1. The ejector mount 36 may also be delimited on the cover side by a cover section 36.3. Preferably, the ejector mount 36 is delimited both by the two lateral surfaces 36.1 and by the cover section 36.3. The lateral surfaces 36.1 may merge into the cover section 36.3 via a rounding transition. Preferably, the rounding transition is formed by a rounding having a radius in the range from 2 mm to 8 mm to reduce the risk of dirt accumulation. Preferably, the cover section 36.3 is disposed in parallel to the bearing surface 31 to achieve an improved discharge effect. This is illustrated in Figure 9. The lateral surfaces 36.1 of the ejector mount 36 can merge into the contour of the pick mount 32 via transition sections 36.2. Figure 7 illustrates that the ejector mount 36 extends outward from an inner opening area 36.4 toward the rear side of the pick holder 30 to form an ejector passage opening 36.5. Figure 14 illustrates that the width of the ejector mount 36 may, at least in partial areas, widen toward the exterior, that is, toward the ejector passage opening 36.5. Preferably, the width of the ejector mount 36 widens continuously. To this end,provision may be made, for instance, for the lateral surfaces 36.1 to be angled relative to each other and to form an opening angle p. This opening angle p may preferably be selected in the range from 20° to 45°, more preferably from 25° to 40°, particularly preferably from 30° to 35°, or in particular from 29° to 34°. Preferably, the central longitudinal plane ME of the pick holder 30 may be equal to the bisector of the opening angle p. In the area of the end of the ejector mount 36 facing the pick mount 32, the ejector mount 36 has a minimum inner transverse extent 36.6, and in the area of the ejector passage opening 36.5, it has a maximum outer transverse extent 36.7. The ratio of the outer transverse extent 36.7 to the inner transverse extent 36.6 is preferably selected to be in the range from 1.3 to 2.2, more preferably from 1.5 to 2, and particularly preferably from 1.7 to 1.9. When the pick holder 30 is used in a road-milling application, it has proven advantageous for the outer transverse extent to be at least 30 mm. As shown, for instance, in Figures 9 and 12, provision may be made, either alternatively or additionally, for the ejector mount 36 to have an exit height hA in the area of the ejector passage opening 36.5 and an entry height hE in the area where the ejector mount 36 transitions into the pick mount 32. The entry height hE and the exit height hA are measured in the direction of the central longitudinal axis M of the pick mount 32. As shown in Figure 9, the entry height hE and the exit height hA are measured in this case relative to the cover section 36.3. Preferably, the entry height hE is greater than the exit height hA. To achieve good conveying performance, it is preferable to select a ratio of the entry height hE to the exit height hA in the range from 0.6 to 0.9. Figure 9 illustrates that the ejector mount 36 forms an entry cross-section EQ in the inner opening area and an exit cross-section AQ at the ejector passage opening 36.5, wherein the entry cross-section EQ and the exit cross-section AQ are each measured perpendicular to the central longitudinal plane ME of the pick holder 30. Preferably, the ratio of the area of the exit cross-section AQ to the area of the entry cross-section EQ is selected to be in the range from 1.0 to 1.5, preferably from 1.0 to 1.4, and particularly preferably from 1.1 to 1.3. As the figures illustrate, the pick holder 30 has a central longitudinal plane ME. Figure 12 shows a longitudinal section through the pick holder 30 along the central longitudinal plane ME. As the illustration shows, the central longitudinal axis M of the pick mount 32 lies in the central longitudinal plane ME. In addition, the longitudinal plug-in attachment axis 44.2 of the plug-in attachment 44 may lie in the central longitudinal plane ME. This is also illustrated in Figure 12. Preferably, the central longitudinal plane ME extends in the feed direction V, as shown in Figure 12. As Figures 5 and 6 show, the support body 35 has a support section 40, which is formed on the underside of the pick holder 30. The support section 40 has two front transfer surfaces 41.1, 41.2. These front transfer surfaces 41.1, 41.2 are disposed at both sides of the central longitudinal plane ME of the pick holder 30. Preferably, as the drawings illustrate, the front transfer surfaces 41.1, 41.2 are each ME disposed completely at the respective sides of the pick holder 30 assigned thereto, laterally next to the central longitudinal plane ME and do not penetrate the central longitudinal plane ME. It is conceivable that the two front transfer surfaces 41.1, 41.2 are interconnected by means of a take-up surface 42. The take-up surface 42 pierces the central longitudinal plane ME. The front transfer surfaces 41.1,41.2 form a transverse support angle a, as shown in Figure 5. Preferably, this angle a is in the range from 100° to 120°. The bisecting line of this angle a preferably lies in the central longitudinal plane ME. As the drawings illustrate, a plug-in attachment 44 is disposed on the underside of the pick holder 30, preferably integrally molded thereon. The front transfer surfaces 41.1, 41.2 are disposed at least sectionally in front of the plug-in attachment 44 in the feed direction. This is illustrated in Figure 6. In addition, the support section 40 has at least one rear transfer surface 43.1, 43.2. In the exemplary embodiment shown, two rear transfer surfaces 43.1, 43.2 are used, which in the exemplary embodiment lie in one plane and are disposed at least sectionally perpendicular to the central longitudinal plane ME and spaced apart from each other. The two rear transfer surfaces 43.1, 43.2 are at a longitudinal support angle P to the front transfer surface 41.1, 41.2 assigned to one side each of the pick holder 30. The longitudinal support angle P between the front transfer surface 41.1 or 41.2 and the matching rear transfer surface 43.1 or 43.2 is preferably selected to be in the range from 120° to 160°. The angle bisector may be oriented such that it intersects the central longitudinal plane ME. Figure 7 shows that the front transfer surfaces 41.1, 41.2 each merge into the rear transfer surfaces 43.1, 43.2 via an inclined surface 42.1. The inclined surfaces 42.1 may each extend in the area between two transverse edges. The front transverse edge facing the front side of the pick holder 30 forms a transition between the front transfer surface 41.1, 41.2 and the inclined surface 42.1. The rear transverse edge facing the rear side of the pick holder 30 forms a transition between the inclined surface 42.1 and the assigned rear transfer surface 43.1, 43.2. The inclined surfaces 42.1 thus merge directly into the front transfer surfaces 41.1, 41.2 or rear transfer surfaces 43.1, 43.2. However, an indirect transition is also conceivable, for instance by means of a rounding transition. As shown in Figures 3 and 6, the inclined surfaces 42.1 can form a reflex angle both with the assigned front transfer surface 41.1, 41.2 and with the rear transfer surface 43.1, 43.2; it is particularly preferred that the inclined surfaces form the same angle with the front transfer surfaces 41.1, 41.2 and with the rear transfer surfaces 43.1, 43.2. The arrangement of the front and rear transfer surfaces 41.1, 41.2, 43.1, 43.2 and the inclined surfaces 42.1 is preferably symmetrical with respect to the central longitudinal plane. The plug-in attachment 44 preferably comprises a cylinder section 44.5, as shown in Figure 6. The cylinder section 44.5 may comprise a front partial-cylinder surface 44.3 and / or a rear partial-cylinder surface 44.4 oriented opposite to the feed direction V. Preferably, the maximum distance between any two transverse edges of the inclined surfaces 42.1, measured in parallel to the central longitudinal plane ME and perpendicular to the longitudinal plug-in attachment axis 44.2, is less than the extent of the cylinder section 44.5 of the plug-in attachment 44, measured in parallel to the central longitudinal plane ME. The maximum distance X (see Figure 15) between the two transverse edges, measured in parallel to the central longitudinal plane ME and perpendicular to the longitudinal plug-in attachment axis 44.2, is (see Figure 15) preferably less than 0.7 times, and more preferably less than 0.5 times, the maximum extent maxE of the cylinder section 44.5 of the plug-in attachment 44, measured in parallel to the central longitudinal plane ME and perpendicular to the longitudinal plugin attachment axis 44.2, as illustrated in Figure 15. The drawings (see Figure 7 in particular) illustrate that the two transverse edges of the inclined surfaces 42.1 are inclined at an angle e < 90° relative to the central longitudinal plane ME, extending from the front side of the pick holder 30 toward the rear side of the pick holder 30. This is illustrated in Figure 7 using one of the transverse edges by way of example. Preferably, the inclined surfaces 42.1 are formed as flat surfaces that extend at an angle e < 90° to the central longitudinal plane ME, with the angle e opening toward the rear side of the pick holder 30 and toward the top of the pick holder 30, as shown in Figure 7. Accordingly, the two inclined surfaces 42.1, when viewed along the longitudinal plug-in attachment axis 44.2, may be oriented at a V-shape relative to each other and diverge from the front side of the pick holder 30 toward the rear side (i.e., in the direction opposite to the feed direction V) of the pick holder 30 (see Figure 14) and / or diverge from the underside of the pick holder 30 toward the top of the pick holder 30 (see Fig. 6). Preferably, the inclined surfaces 42.1 form an angle with each other that is selected within the range of 110° to 150°, to achieve a compact design. The 44-type plug-in attachment of the pick holder protrudes from the underside of the pick holder 30, as shown, for instance, in Figure 6. Advantageously, the plug-in attachment 44 has a three-part design. This structure is divided, along the longitudinal plug-in attachment axis 44.2, into a first, lower shank section, which has a front shankcontact surface 45 and a rear screw pressure surface 47.1, a second, middle shank section, which comprises the cylinder section 44.5, and a third, upper shank section, which comprises a shank widening 44.1. The second middle section is disposed between the first and third shank sections. Preferably, the extent of the first, lower shank area in the direction of the longitudinal plug-in attachment axis 44.2 may be at least 30% of the maximum length of the plugin attachment 44 in that direction, to ensure a stable transfer of the forces from the pressure screw 20 and stable contact between the shank-contact surface 45 and a shank-support surface 18.2 of a bottom part in the installed state. In addition or alternatively, the extent of the second, middle shank area in the direction of the longitudinal plug-in attachment axis 44.2 is at least 10% of the maximum length of the plug-in attachment 44 in this direction, to ensure sufficient elasticity of the plugin attachment 44 in the direction of the longitudinal plug-in attachment axis 44.2. In addition or alternatively, the extent of the third, upper shank area in the direction of the longitudinal plug-in attachment axis 44.2 may be at least 5% of the maximum length of the plug-in attachment 44 in that direction, to achieve effective load transfer from the pick holder 30 to the bottom part 10 in the event of an overload. The rear transfer surfaces 43.1, 43.2 are disposed at clearly visible least sectionally in the feed direction V behind the plug-in attachment 44. At its end facing the support body 35, the plug-in attachment 44 merges into the support body 35 via a shank widening 44.1. The shank widening 44.1 widens the crosssection of the plug-in attachment 44 in the direction of the support body 35 and radially to the longitudinal plug-in attachment axis 44.2, at least sectionally. Preferably, the shank widening 44.1 is formed least sectionally circumferentially on the plug-in attachment 44. The shank widening 44.1 may widen the cross-section of the plug-in attachment 44, at least sectionally, particularly in the transition to the rear transfer surfaces 43.1 and 43.2. In addition or alternatively, provision may be made for the shank widening 44.1 to widen the cross-section of the plug-in attachment 44, at least sectionally, at the transition to the two lateral inclined surfaces 42.1. In addition or alternatively, provision may be made for the shank widening 44.1 to widen the cross-section of the plug-in attachment 44, at least sectionally, at the transition to the two front transfer surfaces 41.1, 41.2. As the representations of Figures 5 and 6 show, the shank widening 44.1 widens the cross-section of the plug-in attachment 44. In this context, provision may be made for the shank widening 44.1 to widen the cross-section of the plug-in attachment 44 in the area of the two sides assigned to the lateral surfaces 35.4. To this end, preferably the shank widening 44.1, with widening sides extending laterally on both sides of the plugin attachment 44, extends from the rear-end stern section to the front-end frontal section of the plug-in attachment 44 and widens the cross-section of the plug-in attachment 44 in these areas toward the support body 35 and radially with respect to the longitudinal plug-in attachment axis 44.2. Preferably, the greatest extent LE of the widening sides in the direction of the longitudinal plug-in attachment axis 44.2 is at least 5%, more preferably at least 10%, and particularly preferably at least 14% of the maximum length LS of the plug-in attachment 44, measured in this direction (see Figure 6). The maximum length LS of the plug-in attachment 44 extends across the shank widening 44.1 to the support body 35 and preferably encompasses the greatest extent LE of the widening sides, as Figure 6 clearly shows. It has proven advantageous if provision is made for the widening sides of the shank widening 44.1 to extend across at least 50% of the maximum extent maxE of the cylinder section 44.5 of the plug-in attachment 44, which extends in parallel to the central longitudinal plane ME and perpendicular to the longitudinal plug-in attachment axis, it is particularly preferred that the widening sides of the shank widening 44.1 extend across the entire depth of the plug-in attachment 44 and, in particular, are formed circumferentially. Preferably, the shank widening 44.1 may also, in addition or alternatively, widen the rear area of the plug-in attachment 44. As the drawings show, particularly preferably the shank widening 44.1 is formed circumferentially. In this exemplary embodiment, the front transfer surfaces 41.1, 41.2 transition via a rounding transition of the shank widening 44.1 to the widening sides of the shank widening 44.1, as shown in Figure 6. The widening sides of the shank widening 44.1 extend in a convex, arched curve to the front end area of the plug-in attachment 44. The shank widening 44.1 may form a rear shank contact 48. The rear shank contact 48 has two lateral contact surfaces 48.1 that are spaced apart from each other. In particular, the lateral contact surfaces 48.1 may be angled in a V-shape relative to each other. As shown in Figure 7, the lateral contact surfaces 48.1 of the rear shank contact 48 may each merge laterally into an assigned widening side of the shank widening 44.1, wherein preferably provision is made for one of the lateral contact surfaces 48.1 to extend, at least sectionally, laterally adjacent to one side of the central longitudinal plane ME, and for the other lateral contact surface 48.1 to extend, at least sectionally, laterally adjacent to the opposite side of the central longitudinal plane ME. Figure 6 further illustrates that the inclined surface 42.1 may also merge laterally into the shank widening 44.1 via a rounding transition, specifically via a relief groove 49. The support body 35, in particular at least a part of the functional surfaces formed on the support body 35, the front and / or rear transfer surfaces 41.1, 41.2, 43.1, and 43.2, and / or the inclined surfaces 42.1 may merge into the shank widening 44.1 via a rounding transition. The rounding transition is part of shank widening 44.1. As the illustrations show, the lateral contact surfaces 48.1 may form an angle that opens, preferably, toward the front side of the pick holder 30. Preferably, provision may be made for the lateral contact surfaces 48.1 to form an angle with each other in the range from 45° to 100°, preferably from 50° to 90°, and particularly preferably from 66° to 76°. Correspondingly, the clamping surfaces 18.5, 18.6 of the rear overload-support area 18.4 of the bottom part 10 may be set relative to each other at an angle in the range from 45° to 100°, preferably from 50° to 90°, and particularly preferably from 66° to 76° relative to each other, as shown in the representations. In one possible embodiment of a pick holder 30, provision may also be made for the angle formed by the lateral contact surfaces 48.1 to be selected to be in the range from 30° to 75°, preferably in the range from 35° to 70°, and particularly preferably in the range from 45° to 55°. Such a design is in particular recommended if provision is made for a pick holder 30 to have two flat rear transfer surfaces 43.1, 43.2 that are angled relative to each other, as described above, for instance. Correspondingly, the clamping surfaces 18.5, 18.6 of the rear overload-support area 18.4 of the bottom part 10 may preferably be oriented at an angle to each other in the range from 30° to 75°, preferably from 35° to 70°, and particularly preferably from 45° to 55°, as shown in the illustrations. Preferably, clamping surfaces 18.5 and 18.6 are parallel to their respective assigned lateral contact surfaces 48.1. In a further embodiment of a pick holder 30, provision may also be made for the angle formed by the lateral contact surfaces 48.1 to be selected to be in the range from 37° to 87°, preferably in the range from 42° to 82°, and particularly preferably in the range from 57° to 67°. This design is in particular recommended if provision is made for a pick holder 30 to have a flat rear transfer surface 43.1, 43.2, or two flat rear transfer surfaces 43.1, 43.2 that are parallel to each other, in particular, flush with each other, as described, for instance, above. Correspondingly, the clamping surfaces 18.5, 18.6 of the rear overload-support area 18.4 of the bottom part 10 may preferably be oriented at an angle to each other in the range from 37° to 87°, preferably from 42° to 82°, and particularly preferably from 57° to 67°, as shown in the illustrations. Preferably, clamping surfaces 18.5 and 18.6 are parallel to their respective assigned lateral contact surfaces 48.1. Figure 14 shows that one lateral contact surface 48.1 is positioned, in whole or in part, to the side of the central longitudinal plane ME, such that one lateral contact surface 48.1 is assigned to each side of the pick holder 30. Preferably, the lateral contact surfaces 48.1 do not pass through the central longitudinal plane ME, as shown in Figure 14. In this case, the two lateral contact surfaces 48.1 are preferably interconnected directly or indirectly via an overload-contact surface 48.2. It is conceivable that the two lateral contact surfaces 48.1 are indirectly connected to the overload-contact surface 48.2 via a rounding transition 48.3. Preferably, the lateral contact surfaces 48.1 form the same angle with the overload-contact surface 48.2, and / or the lateral contact surfaces 48.1 and the overload-contact surface 48.2 are designed to be symmetrical with respect to the central longitudinal plane ME. Preferably, the overload-contact surface 48.2 is designed to be a flat surface. The lateral contact surfaces 48.1 may also be designed as flat surfaces. The drawings illustrate that the overload-contact surface 48.2 and / or the lateral contact surfaces 48.1 can merge at least partially into the rear transfer surfaces 43.1, 43.2 or into one of the rear transfer surfaces 43.1, 43.2. Figure 8 illustrates that the plug-in attachment 44 has a shank section that may preferably comprise, at least sectionally, a cylinder section 44.5. The cylinder section 44.5 may have a front partial-cylinder surface 44.3 and / or a rear partial-cylinder surface 44.4 oriented opposite the feed direction. Preferably, the cylinder section 44.5 forms an at least partially circumferential cylinder, which may be interrupted as the case may be only by one or several lateral indentations 44.6, as shown in Figure 8. The cylinder axis of the cylinder section 44.5 is preferably aligned with the longitudinal plug-in attachment axis 44.2 and, particularly preferably, lies in the central longitudinal plane ME. Preferably, the cylinder section 44.5 adjoins the shank widening 44.1. In a pick holder 30 according to the invention, the widening sides of the shank widening 44.1 may merge laterally, at least sectionally, via rounding transitions into the front and / or rear partial-cylinder surface 44.3, 44.4, and / or the lateral contact surfaces 48.1 of the rear shank contact 48, at least sectionally, may merge via rounding transitions into the rear partial-cylinder surface 44.4, and / or the overload-contact surface 48.2, facing away from the support body 35, may merge, at least sectionally, via a rounding transition into the rear partial-cylinder surface 44.4 At its free end, the plug-in attachment 44 comprises a front shank contact, as illustrated in Figures 5 and 6. The front shank contact has a front shank-contact surface 45. Preferably, the front shank-contact surface 45 comprises two convex sub-surfaces, 45.1 and 45.2. The front shank-contact surface 45 and / or at least one of the subsurfaces 45.1, 45.2 may preferably form a partial-cylinder surface of a cylinder with a contact-cylinder axis Z, as can be seen, among other places, in Figures 8 and 9. Particularly preferably the two sub-surfaces 45.1 and 45.2 are disposed spaced apart from each other, wherein a groove 46 is formed, preferably within the spacing area. The groove 46 is designed to accommodate the molded body mentioned above, which has been inserted into the depression 18.3 of the bottom part 10. This results in an orientation of the pick holder 30 in relation to the bottom part 10 and an anti-rotation device. The groove 46 extends in the direction of the longitudinal extent of the plug-in attachment 44 and preferably in parallel to the contact-cylinder axis Z and / or inclined relative to the longitudinal plug-in attachment axis 44.2. The angle of inclination of the groove 46 (in particular, the bottom of the groove) relative to the longitudinal plug-in attachment axis 44.2 can preferably be selected within the range from 2° to 10°. Figure 8 illustrates that the sub-surfaces 45.1 and 45.2 of the front convex shankcontact surface 45 can be arranged in a specific manner. Figure 8 illustrates a section surface SF of the pick holder 30, which is defined by a section plane SE. The section plane SE extends in parallel to and at a distance from the central longitudinal plane ME through the pick holder 30. The section plane SE intersects at least one of the two front transfer surfaces 41.1, 41.2 of the pair of transfer surfaces and the front shankcontact surface 45. As shown in the drawing, the section surface forms a front section edge SK of the transfer surface 41.1, 41.2 and a front section edge 45.3 of the front shank-contact surface 45. It is evident that the front section edge 45.3 and the front section edge SK form an undercut angle y that is at least 103° and at most 114°. Preferably, the undercut angle y opens toward the front side, that is, in the feed direction V, as shown in Figure 8. The function of this undercut angle y will be explained in more detail later. Figure 8 further illustrates that the projections of the longitudinal plug-in attachment axis 44.2 and the section edge 45.3 onto the central longitudinal plane ME form a shank angle 9 with each other. This shank angle 9 opens toward the free end of the plug-in attachment 44. The shank angle 9 is preferably selected to be in the range from 2° to 10°, and particularly preferably in the range from 2° to 8°. As shown in Figure 9, the front shank-contact surface 45 may preferably form a part-cylindrical peripheral surface. In this case, preferably the contact-cylinder axis Z of the part-cylindrical peripheral surface of the front shank-contact surface 45 and the longitudinal plug-in attachment axis 44.2 form an axial angle n with each other, which opens toward the free end of the plug-in attachment 44. The axial angle n between the contact-cylinder axis Z of the part-cylindrical peripheral surface of the front shank-contact surface 45 and the longitudinal plug-in attachment axis 44.2 can be selected within the range from 2° to 10°, preferably from 2° to 8°, to ensure the secure anchoring of the plug-in attachment 44 in the plug-in mount 18 of the bottom part 10. At this point, it should be noted once again that the cylinder axis of cylinder section 44.5 is preferably defined by the longitudinal plug-in attachment axis 44.2. Due to the inclination of the contact-cylinder axis Z relative to the longitudinal plug-in attachment axis 44.2, the part-cylindrical peripheral surface formed by the front shank-contact surface 45 is inclined relative to the cylinder section 44.5 by an axial angle n, preferably in the range from 2° to 10°, and particularly preferably from 2° to 8°. In the exemplary embodiment illustrated in Figure 9, provision is made, in particular for reasons of symmetry, for the longitudinal plug-in attachment axis 44.2 of the plug-in attachment 44 and the contact-cylinder axis Z of the part-cylindrical peripheral surface of the front shank-contact surface 45 to extend in the central longitudinal plane ME. A particularly preferred embodiment of a pick holder 30 according to the invention may be such that the front section edge 45.3 of the shank-contact surface and the contactcylinder axis Z extend in parallel to each other, and the axial angle n and the shank angle 9 are thus equal, as illustrated in Figure 9. Figure 8 illustrates that provision may be made for at least one lateral contact surface 48.1 of the rear shank contact 48 in the section plane to form a rear section edge 48.1.1 in the section surface SF. Provision may be made for 1. the rear section edge 48.1.1 and / or the overload-contact surface 48.2 to extend in parallel to the longitudinal plug-in attachment axis 44.2 and / or in parallel to the contact-cylinder axis Z, or for the rear section edge 48.1.1 and / or the overload-contact surface 48.2 to extend at an angle t to the longitudinal plug-in attachment axis 44.2 and / or at an angle to the contact-cylinder axis Z, wherein preferably provision is made for the angle t to be selected to be less than 5°. 2. the rear section edge 48.1.1 and / or the overload-contact surface 48.2 to form an angle w with the front section edge 45.3, wherein the angle w preferably opens toward the plug-in attachment side of the pick holder 30, as shown in Figure 8. Preferably, the angle w between the front section edge 45.3 and the rear section edge 48.1.1 and / or the overload-contact surface 48.2 is selected to be in the range from 0.5° to 7°, preferably in the range from 1.5° to 6°, and particularly preferably in the range from 2.5° to 5°. In this way, the safe load transfer via the rear shank contact 48, in particular in the event of an overload is ensured. As shown in Figure 8 and other figures, the plug-in attachment 44 has a screw mount 47 on its rear side, which forms a flat screw pressure surface 47.1. The screw pressure surface 47.1 pierces the central longitudinal plane. The plane in which the screw pressure surface 47.1 lies forms an angle o with the front section edge 45.3 or with the contact-cylinder axis Z of the cylinder that forms the convex front shank contact 45. The pressure angle o is preferably selected in the range from 30° to 45°. Figures 6 and 8 show the spatial assignment of the pressure screw 20 with the screw mount 47 in the installed state of the pick holder 30. As illustrated in Figure 14, a relief groove 49 and / or a rounding transition may be provided in the transition area between the shank widening 44.1 and the support section 33 of the support body 35. The geometry formed by the relief groove 49 and / or the rounding transition may at least partially encircle the plug-in attachment 44. This relief groove 49 and / or the area of the rounding transition may contain a (not shown) sealing element that at least partially encircles the plug-in attachment 44. In such a design, a stress-optimized structure is achieved if provision is made for a concave rounding transition at the plug-in attachment 44 to transition the plug-in attachment 44 into the shank widening 44.1. In addition or alternatively, provision may also be made for the shank widening 44.1 to have a transition geometry having a relief groove 49 and / or a rounding, through which it is transitioned into the support body 35. To install the pick holder 30 on the bottom part 10, the free end of the plug-in attachment 44 is inserted into the plug-in mount 18. The insertion extension 18.1 facilitates the threading of the plug-in attachment 44. The insertion motion of the plug-in attachment 44 into the plug-in mount 18 is delimited by the front support surfaces 15.1, 15.2 and the rear support surfaces 16.1 and 16.2 of the bottom part 10. The front transfer surfaces 41.1, 41.2 or the rear transfer surfaces 43.1, 43.2 of the pick holder 30 strike these support surfaces 15.1, 15.2, 16.1, 16.2. The pressure screw 20 can be screwed into the screw mount 19 of the bottom part 10. To this end, the pressure screw 20 comes into contact with the screw pressure surface 47.1 of the screw mount 47. In so doing, the pick holder 30 is pulled into the plug-in mount 18. As the pressure screw 20 is tightened, the front shank-contact surface 45 slides along the front shank-support surface 18.2, and the pick holder 30 is drawn into the plug-in mount 18. Once the pick holder 30 has reached its installation position, the front transfer surfaces 41.1 and 41.2 are pressed onto the front support surfaces 15.1 and 15.2, and the rear transfer surfaces 43.1 and 43.2 are pressed onto the rear support surfaces 16.1 and 16.2. Simultaneously, the front shank-contact surface 45 of the front shank contact is pressed against the front shank-support surface 18.2 of the bottom part 10. The pick holder 30 is thus securely fastened in the bottom part 10. The lateral contact surfaces 48.1 of the rear shank contact 48 are located at a short distance from the assigned clamping surfaces 18.5, 18.6 of the bottom part 10. This is illustrated in Figure 13. Furthermore, the overload-contact surface 48.2 is at a distance from the clamping surface 18.7 of the bottom part 10. This distance is preferably less than 2 mm, and more preferably less than 1 mm, to minimize the deformation of the pick holder 30 in the event of an overload. If an overload is applied to the pick holder 30, the pick holder 30 undergoes elastic deformation, and the lateral contact surfaces 48.1 come into contact with the assigned clamping surfaces 18.5 and 18.6. In this way, additional support is provided for the pick holder 30. If the overload is particularly high, the clamping surfaces 18.5 and 18.6 undergo elastic deformation and deflect outward toward the assigned sides of the pick holder 30. Next, the overload-contact surface 48.2 comes into contact with the clamping surface 18.7. In this way, the deflection of the clamping surfaces 18.5 and 18.6 is delimited to prevent damage to the bottom part 10 and to provide an additional support area for transferring the overload. Once the overload condition has ended, the pick holder 30 returns to its original position, as shown in Figure 13. In the event of an overload, stresses develop in the pick holder 30 that attempt to dislodge the plug-in attachment 44 of the pick holder 30 from the plug-in mount 18 in the direction of the longitudinal plug-in attachment axis 44.2. Since, as described above, the front shank-contact surface 45, together with the front transfer surfaces 41.1,41.2 each form an undercut angle y selected within the range from at least 103° to a maximum of 114°, an undercut acting in the direction of the longitudinal plug-in attachment axis 44.2 is created, thereby producing a form-fit connection in the direction of the longitudinal plug-in attachment axis 44.2. Thus, this form-fit connection prevents the plug-in attachment 44 from being pulled out of the plug-in mount 18 in the event of an overload. Figure 2 illustrates that, with pick holder 30 installed, an ejector tool can be passed through the ejector mount 36 toward the pick mount 32. Because the ejector mount 36 widens radially from the central longitudinal axis M of the pick mount 32, it provides ample space for the ejector tool. In this way, removing the pick is facilitated. During the machining operation, the machining forces are transferred from the pick holder 30 to the bottom part 10. The force is transferred from the front transfer surfaces 41.1, 41.2 and the rear transfer surfaces 43.1, 43.2 of the pick holder 30 into the front support surfaces 15.1, 15.2 and the rear support surfaces 16.1, 16.2 of the bottom part 10. Now, with increasing service life of the tool, the front transfer surfaces 41.1, 41.2 and the rear transfer surfaces 43.1, 43.2 and / or the front support surfaces 15.1, 15.2 and the rear support surfaces 16.1 and 16.2 may wear out. This causes the pick holder 30 to move towards the bottom part 10. By using the inclined surfaces 42.1, which face the bottom part 10 across the setbacks 17, a generous take-up space (see Figure 3) is created, which compensates for this wear. This means that the pick holder 30 can then continue to be supported reliably and as intended on the front and rear support surfaces 15.1, 15.2, 16.1, 16.2 of the bottom part 10.
Claims
1. A bottom part (10) for mounting a pick holder (30), having a base body (13) that comprises a holder mount (14) for mounting the pick holder (30), wherein the holder mount (14) comprises a plug-in mount (18), wherein the holder mount (14) comprises at least one front support surface (15.1, 15.2), which is disposed at least sectionally in front of and / or to the side of the plug-in mount (18), and wherein the holder mount (14) comprises at least one rear support surface (16.1, 16.2), which is disposed, at least sectionally, behind and / or to the side of the plugin mount (18), characterizedin that the base body (13) comprises two clamping surfaces (18.5, 18.6) of a rear overload-support area (18.4) in the insertion area into the plug-in mount (18), and in that the clamping surfaces (18.5, 18.6) face one side of the base body (13) each.
2. The bottom part (10) according to claim 1, characterized in that the clamping surfaces (18.5, 18.6) each comprise a flat surface portion, in that these surface portions are angled in a V-shape relative to each other, and in that these surface portions form an angle with each other, preferably in the range from 45° to 100°, more preferably from 50° to 90°, particularly preferably from 66° to 76°, or in that these surface portions form an angle with each other in the range from 30° to 75°, preferably in the range from 35° to 70°, particularly preferably from 45° to 55°, or in that these surface portions form an angle with each other in the range from 37° to 87°, preferably in the range from 42° to 82°, particularly preferably in the range from 57° to 67°.
3. The bottom part (10) according to claim 1 or 2, characterized in that the rear overload-support area (18.4) comprises a securing surface (18.7) disposed between the two clamping surfaces (18.5, 18.6).
4. The bottom part (10) according to claim 3, characterized in that both clamping surfaces (18.5, 18.6) each form an angle with the securing surface (18.7), wherein these two angles are preferably equal, and wherein preferably provisionis made for the respective angle between the clamping surfaces (18.5, 18.6) and the securing surface (18.7) to be selected in the range from 40° to 68°, preferably from 45° to 62.5°, and particularly preferably from 52° to 57°.
5. The bottom part (10) according to any of claims 3 or 4, characterized in that the two clamping surfaces (18.5, 18.6) each merge into the securing surface (18.7) via a rounding transition.
6. The bottom part (10) according to any of claims 1 to 5, characterized in that the plug-in mount (18) has, in the area of the top of the base body (13), an insertion extension (18.1) that widens the cross-section of the plug-in mount (18) in the direction from the underside of the base body (13) toward the top of the base body (13) and radially outward, and in that the clamping surfaces (18.5, 18.6) and / or the securing surface (18.7) are disposed at least sectionally within the insertion extension (18.1) and delimit it at least sectionally.
7. The bottom part (10) according to claim 6, characterized in that the insertion extension (18.1) has lateral sections that extend adjacent to the two clamping surfaces (18.5, 18.6) on the sides of the base body (13) and that extend in the direction from the rear side (13.2) of the base body (13) toward the front side (13.1).
8. The bottom part (10) according to any of claims 1 to 7, characterized in that the rear support surface (16.1, 16.2) merges into a front support surface (15.1, 15.2) on both sides of the base body (13) via a respective setback (17) recessed into the base body (13), which setback is preferably formed as a rounding transition, or in that the rear support surfaces (16.1, 16.2) on either side of the base body (13) each merge into a front support surface (15.1, 15.2) via a respective setback (17) recessed into the base body (13), which is preferably formed as a rounding transition,and in that, in the area of the setbacks (17), a respective clamping surface (18.5, 18.6) of the rear overload-support area is disposed, at least sectionally.
9. The bottom part (10) according to any of claims 1 to 8, characterized in that at least one front shank-support surface (18.2) of a front shank contact is provided in the plug-in mount (18) and facing the underside of the base body (13), in that the front shank-support surface (18.2) is disposed on the side of the plug-in mount (18) opposite the rear overload-support area (18.4), wherein preferably provision is made for the front shank-support surface (18.2) to be divided into two subsurfaces by means of a depression (18.3) formed in the base body (13).
10. The bottom part (10) according to any of claims 1 to 9, characterized in that the front shank-support surface (18.2) comprises a partial-cylinder surface of a hollow cylinder, and in that the cylinder axis of this hollow cylinder forms a clamping angle in the range from 5° to 15°, preferably in the range from 9° to 12° with the clamping surfaces (18.5, 18.6) of the overload-support area (18.4) and / or the overload-contact surface (18.4) of the overload-support area (18.4).
11. The bottom part (10) according to any of claims 1 to 10, characterized in that the two front support surfaces (16.1, 16.2) are separated from each other at the front by means of a setback (15.3), wherein preferably provision is made for the setback (15.3) to be disposed opposite the overload-support area (18.4).
12. The bottom part (10) according to any of the claims 1 to 11, characterized in that the rear support surfaces (16.1, 16.2) are separated from each other by a transition section (16.3) recessed into the base body (13) and in that the transition section (16.3) is disposed in the area of the rear overload-support area (18.4).
13. The bottom part (10) according to claim 12, characterized in that the transition section (16.3) comprises a surface area set back relative to the rear support surfaces (16.1, 16.2), which merges at least partially into the clamping surfaces (16.1, 16.2) and / or into the securing surface (18.7).
14. A tool combination having a bottom part (10) according to any of claims 1 to 13 and a pick holder (30), wherein the pick holder (30) is inserted into the plug-in mount (18) of the bottom part (10) via a plug-in attachment (44), and the transfer surfaces (41.1, 41.2, 43.1, 43.2) of the pick holder (30) rest against the supportsurfaces (15.1, 15.2, 16.1, 16.2) of the bottom part (10), and wherein the pick holder (30) has a rear shank contact (48) having lateral contact surfaces (48.1) that face the clamping surfaces (18.5, 18.6).