EP2473434B1 - Cutting tool - Google Patents

Description

The invention relates to a cutting tool for cutting a flat portion of a flat structure, in particular a thin-walled wall portion of a container, and for receiving the flat portion or the cut wall portion in the cutting tool according to the preamble of claim 1 and as shown in US 1 789 729 known.

Such cutting tools are known. They are e.g. used for opening cans or beverage cans. Mostly this is done from a e.g. cylindrical canning or beverage can cut the end face by the cutting tool, wherein a part of the can wall is partially or completely cut out. If only partially cut out, the cut-out portion of the can wall can be bent into or out of the can to create a sufficiently large opening in the can.

When cutting out completely, it is best to prevent the cut-out part from falling into the can and its contents, especially for hygienic reasons. For this purpose, there are cutting tools in the form of a cylindrical wall, in which one of the frontal edges is ground as a cutting blade. When such a cutting tool is pressed with its cutting blade against a can wall, with sufficient sharp cutting blade and / or sufficiently strong pressing of the cutting blade against the can wall, the part of the can wall can usually be easily cut out. On the other hand, there are always problems in picking up the cut-out portion of the can wall in the cutting tool. If the surface of the inner wall of the cylindrical cutting tool is a smooth, pure cylinder surface, it may occur in successively cutting out wall sections from identical cans that the cut-out part of the can wall clamps inside the cylinder, or that the cut-out part of the can from the inside of the cylinder and falls into the can. As for the difference between falling out clipping and moderately jammed, ie easily removable from the cutting tool Cutout only very small differences in the dimensions of the cut-out part and / or in the geometry of the receiving cylinder are responsible, so far no satisfactory results could be achieved with reproducible cutting and clamping the can wall cutout.

There were attempts to barb on the inside of the cutting tool, ie on the inner cylinder wall to achieve a more reliable result, such as in the US 1 789 729 is described. Again, this did not result in reproducible cutting and clamping. Rather, such cutting tools especially when cutting tin cans and clamping the cut parts to form metal shavings that can get into the can. This is unacceptable in both cans and beverage cans.

The invention has for its object to provide a cutting tool of the type described above, which works reproducibly and arise in the virtually no chips, in particular no metal chips.

To solve the invention, the invention provides a cutting tool for cutting a flat portion of a sheet-like structure, in particular a thin-walled wall portion of a container, and for receiving the flat portion or the cut wall portion in the cutting tool. The cutting tool is formed by a base body. This main body has, at least in a partial region, a prism-shaped hollow body with a prism-shaped jacket wall whose end edge is shaped as a cutting edge extending along the circumferential direction of the prism-shaped hollow body and bordering the end opening of the hollow body. The base body also has a connection region for connecting the base body to a drive means. The front edge of the prism-shaped jacket wall which is shaped as a cutting edge has a course along the circumferential direction with different axial positions in the axial direction of the prism-shaped hollow body. The front edge provided with the cutting edge has at least in two cutting edge peripheral portions each having along the axial direction projecting cutting edge portion, on the inside of the prismatic shell wall inner surface has a recess which is adjacent to the respective projecting cutting edge portion of the cutting edge. According to the invention, the cutting edge extends continuously along the entire circumferential direction of the prism-shaped hollow body; wherein each serving as a trimmer axially withdrawn cutting edge portion is disposed between serving as a pre-cutter axially projecting cutting edge portions. The coats-wall inner surface has at the projecting cutting edge sections along the axial direction to the cutting edge an oblique course, in which the measured from a longitudinal axis L of the prismatic hollow body radial distance Ri from the longitudinal axis L to the shell wall inner surface along the axial direction to the cutting edge increases; or the shell wall inner surface has at the projecting cutting edge portions a recess in the form of an annular groove which does not border to the tip of the respective projecting portions; and the jacket wall inner surface does not have an oblique course at the withdrawn cutting edge sections, ie here the radial distance Ri measured from the longitudinal axis L of the prismatic hollow body is constant from the longitudinal axis L to the shell wall inner face along the axial direction.

At a continuous cutting edge region adjoining such a depression, the projection of the cutting edge profile on a plane orthogonal to the axial direction, such as the plane of the planar structure, has a bulge or an "ear" (see Fig. 6 and Fig. 12 ). When a section is cut out of a flat structure, a bulge, which corresponds to the bulge in said projection of the cutting edge profile, is formed on the cut-out flat section.

Due to the at least two axially projecting cutting edge sections, each with a recess adjacent to this cutting edge portion in the shell wall inner surface is obtained when cutting the portion of the sheet a section with two bulges.

In general, where the recess of the casing wall inner surface adjoins the cutting edge, the profile of the projection of the cutting edge and the outline of the flat portion cut out with such a cutting edge have a bulge. At these bulges or "ears" of which the area cut out according to the invention has at least two, the section in the interior of the hollow body clamps firmly to the prism-shaped jacket wall, which adjoins the projecting cutting edge sections. The clamped over such bulges flat sections or wall sections clamp firmly enough to prevent their uncontrolled falling out of the prismatic hollow body. On the other hand, they do not clamp so hard that you have to exert very large impact forces for their ejection.

To produce the cutting tool according to the invention, it is possible to start from a prism-shaped hollow body which forms the main body of the cutting tool. It is then possible in a first step of the end edge, which runs around the end opening of this hollow body, e.g. by grinding and sharpening, to impart a cutting edge course along the circumferential direction that has different axial positions, i. has axially projecting cutting edge portions along the axial direction of the prismatic hollow body. In a second step, the recesses can then be worked into the jacket wall inner surface in the areas of the protruding cutting edge sections. At the points where the recesses hit the cutting edge, bulges occur in the projection of the cutting edge profile. The two steps can also be performed in reverse order. After having made the recesses in the shell wall inner surface of the base body in a first step, the grinding and sharpening takes place in a second step, wherein it ensures that the cutting edge produced crosses the recesses. In the places where the cutting edge crosses the recesses, bulges arise in the projection of the cutting edge course.

Preferably, in the cutting tool, the axially projecting cutting edge portions are rounded tips.

In a specific embodiment, the cutting edge has at least in two circumferential regions in the axial direction in each case a projecting portion on which the shell wall inner surface along the axial direction to the cutting edge has an oblique course, wherein the measured from a longitudinal axis of the prismatic hollow body radial distance to the shell wall inner surface increases along the axial direction to the cutting edge.

This causes the first, simultaneous impact of the projecting portions of the cutting edge on a (practically flat) thin-walled wall portion of a container, the first bleed or puncture takes place at points that are based on the cut-out part of the container wall farther out. If the cutting edge now penetrates somewhat deeper into the container wall, the radial distance measured from the longitudinal axis of the penetrating prismatic hollow body to the casing wall inner surface decreases along the axial direction toward the cutting edge. This decrease in the radial distance between the cutting edge and the longitudinal axis of the prism-shaped hollow body takes place at least in two peripheral regions in which the axially projecting portions, so-called. Pre-cutter or tips are arranged. This increasing reduction of the cross-sectional area in the interior of the prism-shaped hollow body when the cutting edge penetrates into the container wall causes a defined deformation of the cut-out wall section on the inner wall of the prismatic hollow body and, if necessary, also a swaging of the cut-out wall section during its cutting. As a result, the cut-out wall section is clamped in a reproducible manner in the interior of the prism-shaped hollow body.

The cutting tool according to the invention is suitable for cutting thin metal (sheet metal), in particular aluminum, and for cutting thin polymer material (foil, sheets, thin plates), in particular polyethylene terephthalate (PET), polybutylene terephthalate (PBT), cellulose-based material such as paper or cardboard , or starch-based materials such as flat-rolled or pressed foods.

For cutting thin polymer material, it is advantageous if the cutting tool is heated. Depending on the polymer material, an optimum cutting tool temperature for cutting can then be set.

Preferably, the jacket wall inner surface of the cutting tool only in the peripheral regions with the respective projecting cutting edge portions of the inclined edge to the cutting edge. The oblique course of the shell wall inner surface may be formed by a flat ground or by a curved ground.

Similar to the jacket wall inner surface, the jacket wall outer surface preferably also has an oblique course along the axial direction up to the cutting edge, wherein the radial distance measured from a longitudinal axis of the prismatic hollow body to the jacket wall outer surface decreases along the axial direction towards the cutting edge.

Preferably, the peripheral regions are distributed uniformly with the axially protruding portions along the circumferential direction.

The prism-shaped hollow body may have a circular, an oval or a polygonal cross-section.

A cylindrical cutting tool with a circular cross section is particularly easy to produce. The pits may be e.g. be prepared by grinding an annular groove on the cylindrical shell wall inner surface. Thereafter, the protrusions in the projection of the cut edge course can be made by crossing the previously prepared annular groove during grinding and sharpening of the cylinder wall end edge. Again, the order of the two steps can be reversed.

Conveniently, the prism-shaped shell wall, at least in the region of its cutting edge made of steel, ceramic or tungsten carbide.

In a particularly advantageous embodiment, the axial length (b) of the area with the recess on the shell wall inner surface at the projecting portions is smaller than the maximum difference (a) of the various axial positions of the cutting edge along the circumferential direction.

In a further advantageous embodiment, the jacket wall inner surface of the prism-shaped hollow body has a microscopically rough surface and / or macroscopic elevations at least in an axial subregion of the inner surface.

Preferably, the surface profile of the shell wall inner surface (4a) and the surface profile of the shell wall outer surface (4b) along the axial direction blunt edges (8) of at least 120 ° or changes in direction of the surface tangent (d or e) of at most 60 °.

Preferably, the cutting tool has a plunger, which extends through a plunger opening of the base body and / or stored in this, and which is axially reciprocally movable inside the prism-shaped hollow body, so that contained in the interior of the hollow body cut wall portions of the hollow body can be ejected.

It is particularly advantageous if the cutting tool has an outlet opening in addition to the end opening, so that inside the prism-shaped hollow body previously recorded and optionally stacked cut wall sections can be ejected via later cut-out cut-out sections in the hollow body.

Alternatively, a suction device can also be connected to the outlet opening, so that cut-out wall sections contained in the interior of the hollow body can be sucked out of the hollow body.

The connecting portion of the cutting tool may include a handle. In particular, the cutting tool may have a pincer-like or clip-like holding device, on whose first leg the base body having the cutting edge is fastened by means of its connection region, and on whose second leg of the thin wall portion having container is fastened, so that by a relative movement of the two legs, the cutting edge can be pressed against the thin-walled wall portion and through it.

The prism-shaped hollow body can have an expanded cross-section in a partial region of its inner wall along its axial direction. In this axial region of the hollow body, cut-out portions can be loosely stacked, so that after a certain number of opening or cutting operations, the ejection of the accumulated in the cavity sections can be done without much effort.

• Fig. 1 eine Draufsicht auf ein erstes Ausführungsbeispiel des erfindungsgemässen Schneidwerkzeugs entlang seiner Längsachse L zeigt;
• Fig. 2 eine Seitenansicht des Ausführungsbeispiels der Fig. 1 quer zu seiner Längsachse L zeigt;
• Fig. 3 eine vergrösserte Ansicht einer Einzelheit des erfindungsgemässen Schneidwerkzeugs im eingekreisten Bereich Z der Fig. 1 zeigt;
• Fig. 4 eine Ansicht des erfindungsgemässen Schneidwerkzeugs entlang der Schnittebene X-X der Fig. 1 ist;
• Fig. 5 eine Ansicht des erfindungsgemässen Schneidwerkzeugs entlang der Schnittebene Y-Y der Fig. 1 ist;
• Fig. 6 eine Draufsicht auf einen ausgeschnittenen flächigen Abschnitt zeigt, der mit einem Schneidwerkzeug gemäss dem ersten Ausführungsbeispiel hergestellt wurde;
• Fig. 7 eine Draufsicht auf ein zweites Ausführungsbeispiel des erfindungsgemässen Schneidwerkzeugs entlang seiner Längsachse L zeigt;
• Fig. 8 eine Seitenansicht des Ausführungsbeispiels der Fig. 7 quer zu seiner Längsachse L zeigt;
• Fig. 9 eine vergrösserte Ansicht einer Einzelheit des erfindungsgemässen Schneidwerkzeugs im eingekreisten Bereich Z der Fig. 7 zeigt;
• Fig. 10 eine Ansicht des erfindungsgemässen Schneidwerkzeugs entlang der Schnittebene X-X der Fig. 7 ist;
• Fig. 11 eine Ansicht des erfindungsgemässen Schneidwerkzeugs entlang der Schnittebene Y-Y der Fig. 7 ist; und
• Fig. 12 eine Draufsicht auf einen ausgeschnittenen flächigen Abschnitt zeigt, der mit einem Schneidwerkzeug gemäss dem zweiten Ausführungsbeispiel hergestellt wurde.

Further advantages, features and applications of the invention will become apparent from the following description of preferred embodiments of the inventive cutting tool with reference to the drawing, wherein:

• Fig. 1 shows a plan view of a first embodiment of the inventive cutting tool along its longitudinal axis L;
• Fig. 2 a side view of the embodiment of Fig. 1 transverse to its longitudinal axis L shows;
• Fig. 3 an enlarged view of a detail of the inventive cutting tool in the circled area Z of Fig. 1 shows;
• Fig. 4 a view of the inventive cutting tool along the cutting plane XX of Fig. 1 is;
• Fig. 5 a view of the inventive cutting tool along the cutting plane YY of Fig. 1 is;
• Fig. 6 shows a plan view of a cut-out flat portion, which was produced with a cutting tool according to the first embodiment;
• Fig. 7 shows a plan view of a second embodiment of the inventive cutting tool along its longitudinal axis L;
• Fig. 8 a side view of the embodiment of Fig. 7 transverse to its longitudinal axis L shows;
• Fig. 9 an enlarged view of a detail of the inventive cutting tool in the circled area Z of Fig. 7 shows;
• Fig. 10 a view of the inventive cutting tool along the cutting plane XX of Fig. 7 is;
• Fig. 11 a view of the inventive cutting tool along the cutting plane YY of Fig. 7 is; and
• Fig. 12 shows a plan view of a cut-out flat portion, which was prepared with a cutting tool according to the second embodiment.

In Fig. 1 is a plan view of a first embodiment of the inventive cutting tool 1 along its longitudinal axis L shown. The cutting tool 1 is for cutting out a thin-walled wall portion from a container such as a beverage can (not shown) and for receiving the cut-out wall portion in the cutting tool 1. For this purpose, the cutting tool 1 has four projecting portions 5a, 5b, 5c along its cutting edge 5 and 5d and four retracted portions 5e, 5f, 5g and 5h (see also FIG Fig. 2 ). In addition, at the connection area 6 (see Fig. 2 ), a central hole 6a is provided on which the cutting tool 1 can be connected to a drive means (not shown).

In Fig. 2 is a side view of the embodiment of Fig. 1 shown transversely to its longitudinal axis L. The cutting tool 1 is formed by a main body 2, which has a prism-shaped hollow body 3 in a partial region. This hollow body 3 is formed by a prism-shaped jacket wall 4, the end edge 5 of which is shaped as a cutting edge 5 extending along the circumferential direction of the prism-shaped hollow body 3 and encompassing its front opening Fig. 2 points upwards. At his in Fig.2 downwardly facing end of the main body 2 has its connection portion 6 with the hole 6 a, where it can be connected to the (not shown) drive means. The drive means may be a hand operated, levered machine in which the cutting tool up and down by muscle power via a lever assembly can be moved. A can, eg beverage can, can be fixed in the machine.

The cutting edge 5 has along its circumferential direction a course with different axial positions in the axial direction of the prismatic hollow body 3. In the present example, the cutting edge 5 in four peripheral regions axially projecting portions 5a, 5b, 5c and 5d (see Fig. 1 ), of which in Fig. 2 only the two sections 5a and 5b are visible. At these projecting portions 5a, 5b, 5c and 5d, which serve as "pre-cutter" and "wide cutter", the shell wall inner surface 4a along the axial direction to the cutting edge 5 has an oblique course 7a (see Fig. 3 ). In this oblique course, the radial distance Ri measured from the longitudinal axis L of the prism-shaped hollow body 3 increases from the longitudinal axis L to the casing wall inner surface 4a along the axial direction towards the cutting edge 5.

Between its projecting portions 5a, 5b, 5c and 5d, the cutting edge 5 has retracted portions 5e, 5f, 5g and 5h (see Figs Fig. 1 ), of which in Fig. 2 only the sections 5e, 5f and 5h are visible. At these sections 5e, 5f, 5g and 5h, which serve as a "trimmer", the casing wall inner surface 4a has no oblique course 7a (see Fig. 3 ). Here, the radial distance Ri measured from the longitudinal axis L of the prismatic hollow body 3 is constant from the longitudinal axis L to the shell wall inner surface 4a along the axial direction.

Thus, when moving the cutting tool 1 downwards against a can, the lid can be cut open at the can end face and finally cut out. At the protruding portions 5a, 5b, 5c and 5d, which are rounded tips, the can lid is first pierced. During the subsequent further penetration of the sections 5e, 5f, 5g and 5h of the cutting tool 1 into the can lid, the latter is completely cut out and is clamped in the interior 11 of the hollow body 3 by the jacket wall inner surface 4a.

In Fig. 3 is an enlarged view of a detail of the inventive cutting tool in the circled area Z of Fig. 1 shown. An oblique course 7a in the form of an oblique cut on the cutting edge 5 can be seen on the casing wall inner surface 4a. This oblique course 7a is only at the regions with the projecting portions or rounded tips 5a, 5b, 5c and 5d of the casing wall inner surface 4a formed. In the remaining areas along the circumferential direction of the cutting edge 5, the jacket wall inner surface 4a has no oblique course 7a.

In Fig. 4 is a view of the inventive cutting tool 1 along the cutting plane XX of Fig. 1 shown, and in Fig. 5 is a view of the inventive cutting tool along the cutting plane YY of Fig. 1 shown. The acute angle f is in the range of 5 ° to 90 °, preferably in the range of 10 ° to 60 °, and most preferably in the range of 25 ° to 45 °. The acute angle f is the angle at the tapered cutting edge 5 between the bevel 7a on the shell wall inner surface 4a and the bevel 7b on the shell wall outer surface 4b. The chamfer 7a forms an angle d to the longitudinal axis L. The chamfer 7b forms an angle e to the longitudinal axis L. The acute angle f is the sum of the angles d and e.

Fig. 4 shows a section through a protruding portion 5 b as one of the four protruding portions (see section XX in Fig. 1 ). From the connecting region 6, the cylindrical jacket wall 4 extends to the cutting edge 5. The jacket wall inner surface 4a is a cylinder wall with radius Ri (see Fig. 2 ) and has only in the region of the cutting edge 5 an oblique course 7a, which may be formed as a flat or conical ground. The jacket wall outer surface 4b is a cylinder wall with radius Ra (see Fig. 2 ) and in the region of the cutting edge 5 also has an oblique course 7b, which is designed as a conical cut and extends along the entire circumferential direction of the cutting tool 1. The in Fig. 4 shown in section projecting portion 5b of the cutting edge 5 serves as a "pre-cutter". The same function has the other three protruding sections 5a, 5c and 5d of the cutting edge 5. These four Pre-cutters 5a, 5b, 5c and 5d are distributed uniformly along the circumferential direction of the cutting tool 1.

Fig. 5 shows a section through retracted portion 5f as one of the four retracted sections (see section YY in Fig. 1 ). From the connecting region 6, the cylindrical jacket wall 4 extends to the cutting edge 5. The jacket wall inner surface 4a is a cylinder wall with radius Ri (see Fig. 2 ) and has only in the area of the cutting edge 5 no oblique course 7a. The jacket wall outer surface 4b is a cylinder wall with radius Ra (see Fig. 2 ) and in the region of the cutting edge 5 also has an oblique course 7b, which is designed as a conical cut and extends along the entire circumferential direction of the cutting tool 1. The in Fig. 5 shown in section withdrawn section 5f of the cutting edge 5 serves as a "trimmer". The same function, the other three retracted portions 5e, 5g and 5h of the cutting edge 5. These four reamers 5e, 5f, 5g and 5h are also distributed uniformly along the circumferential direction of the cutting tool 1.

The axial length b of the inclined slope portion 7a on the precuters 5a, 5b, 5c and 5d of the shell wall inner surface 4a is smaller than the maximum axial difference a between the various projected axial positions 5a, 5b, 5c, 5d and the various retracted ones axial positions 5e, 5f, 5g, 5h of the cutting edge 5 along the circumferential direction.

In the plan view of Fig. 1 and more clearly in the enlarged plan view of Fig. 3 It can be seen how the cutting edge 5 along the annulus, which is formed by the axial projection of the cylindrical shell wall 4, extending snaking. In the areas 5a, 5b, 5c and 5d, the section of the Fig. 4 correspond (pre-cutter), the cutting edge 5 extends from the inner circle, which is formed by the shell wall inner surface 4a, inside the surface of the circular ring projection and back to the inner circle. In the intermediate areas 5e, 5f, 5g and 5h, the section of the Fig. 5 correspond (trimmer), the cutting edge 5 runs on the inner circle projection.

The obtuse angles g and h (see Fig. 4 respectively. Fig. 5 ) at the transitions from the cylindrical shell wall inner surface 4a to the bevel 7a and from the cylindrical shell wall outer surface 4b to the bevel 7b are each at least 120 °. This corresponds to changes in direction d or e of the surface tangent in the axial direction L of at most 60 ° and an acute angle f = d + e of at most 60 °.

The cutting tool 1 according to the invention is suitable for cutting out a thin-walled wall section from a tin can, e.g. an aluminum beverage can, or from a polymer container, such as e.g. a container of polyethylene terephthalate (PET), and for receiving the cut-out wall portion in the interior 11 of the cutting tool first

Specifically for the cylindrical geometry of the illustrated embodiment, it can also be said that the large or outer cutting circle SKG determined by the cutting edge positions of the precut bevel 5a, 5b, 5c and 5d at a respective tooth tip (see Fig. 4 ) has a larger diameter than the small or inner cutting circle SKK determined by the cutting edge positions of the reamers 5e, 5f, 5g and 5h on a respective tooth base (see Fig. 5 ). The difference between the diameters of the two cutting circles SKG and SKK is 2c (see Fig. 4 ).

If the cutting edge 5 now penetrates slightly deeper into the container wall, a defined deformation of the cut-out wall section takes place on the inner wall 4a of the cylindrical hollow body 3 and, if necessary, also a swaging of the cut-out wall section during its cutting. The cut-out wall section is thereby clamped in a reproducible manner in the interior 11 of the cylindrical hollow body 3.

In Fig. 4 and in Fig. 5 can be seen on the prism-shaped hollow body 3, a portion 4c of its inner wall, which has along its axial direction an expanded cross-section. In this axial region of the hollow body 3, cut-out portions 12 (see Fig. 6 ) are stacked loosely, so that after a certain number of opening or Ausschneidevorgängen the ejection of the accumulated in the cavity 3 sections 12 can be done without much effort.

In Fig. 6 is a plan view of a cut-out flat portion 12, which was prepared with a cutting tool 1 according to the first embodiment. The outer edge 13 of the portion 12 has four circumferentially uniformly distributed protrusions 13a, 13b, 13c and 13d (exaggerated) made by the protruding portions 5a, 5b, 5c and 5d, respectively. The course of the projection of the cutting edge 5 (see Fig. 1 and Fig. 3 ) corresponds to the course of the outer edge 13 of the section 12th

In Fig. 7 is a plan view of a second embodiment of the inventive cutting tool along its longitudinal axis L shown. This second embodiment differs from the first embodiment in that in the protruding portions 5a ', 5b', 5c 'and 5d' a recess 7a 'is provided in the form of an annular groove. This recess 7a 'does not abut the tip of the respective projecting portions 5a', 5b ', 5c' and 5d '. At the locations where this annular groove recess 7a 'is cut by the cutting edge 5 (see Fig. 8 ), the projection of the cutting edge course has a bulge. Since the annular groove recess 7a 'is crossed twice by the cutting edge at each protruding portion, two protrusions in the cutting edge projection are produced at each protruding portion 5a', 5b ', 5c' and 5d '(see Figs Fig. 7 and Fig. 9 ).

In the FIGS. 7 to 12 are parts which have the same reference numerals as in the FIGS. 1 to 6 wear, identical with these parts.

In Fig. 12 is a plan view of a cut-out flat portion 12 'shown with a cutting tool 1' according to the second Embodiment was made. The outer edge 13 'of the portion 12' has four circumferentially uniformly distributed bulge pairs 13a ', 13b', 13c 'and 13d' (exaggerated) formed by the protruding portions 5a ', 5b', 5c 'and 5d', respectively were. The course of the projection of the cutting edge 5 '(see Fig. 7 and Fig. 9 ) corresponds to the course of the outer edge 13 'of the section 12'.

Claims (15)

1. Cutting tool (1, 1') for cutting out a flat section from a flat structure, in particular a thin-walled wall section out of a container, and for receiving the flat section or respectively the cut-out wall section in the cutting tool, the cutting tool (1) being formed by a base body (2) having at least in one portion a prism-shaped hollow body (3) with a prism-shaped jacket wall (4) whose leading edge is formed by a cutting edge (5; 5') extending along the circumferential direction of the prism-shaped hollow body (3) and bordering the front opening of the hollow body; and having a connecting region (6) for connecting the base body (2) to a drive means; whereby the leading edge of the prism-shaped jacket wall (4) formed as cutting edge (5; 5') has a course along the circumferential direction with different axial positions in axial direction of the prism-shaped hollow body (3), the leading edge provided with the cutting edge (5; 5') having in each of at least two cutting edge circumferential regions a cutting edge section (5a, 5b, 5c, 5d; 5a', 5b', 5c', 5d') protruding along the axial direction, on whose inner side the prism-shaped jacket wall-inner surface (4a) has a recess (7a; 7a'), which borders on the respective protruding cutting edge section (5a, 5b, 5c, 5d; 5a', 5b', 5c', 5d') of the cutting edge (5; 5'), characterised in that the cutting edge (5; 5') extends continuously along the entire circumferential direction of the prism-shaped hollow body (3); and that disposed between the axially protruding cutting edge sections (5a, 5b, 5c, 5d; 5a', 5b', 5c', 5d') serving as pre-cutter is in each case an axially set-back cutting edge section (5e, 5f, 5g, 5h) serving as post-cutter;
   whereby a) the jacket wall inner surface (4a) has on the protruding cutting edge sections (5a, 5b, 5c, 5d) along the axial direction to the cutting edge a slanted course (7a), in which the radial distance Ri measured from a longitudinal axis L of the prism-shaped hollow body (3) increases to the cutting edge (5) along the axial direction from the longitudinal axis L to the jacket wall inner surface (4a); or b) the jacket wall inner surface (4a) has on the protruding cutting edge sections (5a', 5b', 5c', 5d') a recess (7a') in the shape of an annular groove, which does not border all the way to the tip of the respective protruding sections (5a', 5b', 5c', 5d'); and
   whereby the jacket wall inner surface (4a) has on the set-back cutting edge sections (5e, 5f, 5g, 5h) no slanted course, in which the radial distance Ri measured from the longitudinal axis L of the prism-shaped hollow body (3) is constant along the axial direction from the longitudinal axis L to the jacket wall inner surface (4a).
2. Cutting tool according to claim 1, characterised in that the axial protruding cutting edge sections (5a, 5b, 5c, 5d; 5a', 5b', 5c', 5d') have rounded tips.
3. Cutting tool according to claim 1 or 2, characterised in that the cutting edge (5) has at least in two circumferential regions in axial direction one protruding section (5a, 5b, 5c, 5d) each, on which the jacket wall inner surface (4a) has a slanted course (7a) along the axial direction to the cutting edge (5a, 5b, 5c, 5d), whereby the radial distance (Ri) measured from a longitudinal axis (L) of the prism-shaped hollow body (3) to the jacket wall inner surface (4a) increases to the cutting edge (5) along the axial direction.
4. Cutting tool according to claim 3, characterised in that the jacket wall inner surface (4a) has the course (7a) slanted to the cutting edge (5) only in the circumferential regions with the respective protruding cutting edge sections (5a, 5b, 5c, 5d).
5. Cutting tool according to claim 3 or 4, characterised in that the slanted course (7a) of the jacket wall inner surface (4a) is formed by a flat grinding or by a curved grinding.
6. Cutting tool according to one of the claims 1 to 5, characterised in that the jacket wall outer surface (4b) along the axial direction to the cutting edge (5) has a slanted course (7b), the radial distance (Ra) measured from a longitudinal axis (L) of the prism-shaped hollow body (3) to the jacket wall outer surface (4b) decreasing to the cutting edge (5) along the axial direction.
7. Cutting tool according to one of the claims 1 to 6, characterised in that the circumferential regions with the sections (5a, 5b, 5c, 5d) protruding in axial direction are evenly distributed along the circumferential direction.
8. Cutting tool according to one of the claims 1 to 7, characterised in that the prism-shaped hollow body (3) has a circular, oval or polygonal cross section.
9. Cutting tool according to one of the claims 1 to 8, characterised in that the prism-shaped jacket wall (4) at least in the region of its cutting edge (5) consists of steel, ceramic material or carbide.
10. Cutting tool according to one of the claims 1 to 9, characterised in that the axial length (b) of the region with the recess (7a; 7a') on the jacket wall inner surface (4a) in the protruding sections (5a, 5b, 5c, 5d) is smaller than the maximal difference (a) of the different axial positions of the cutting edge (5) along the circumferential direction.
11. Cutting tool according to one of the claims 1 to 10, characterised in that the jacket wall inner surface (4a) of the prism-shaped hollow body (3) has at least in an axial portion of the inner surface a microscopically rough surface and/or macroscopic protrusions.
12. Cutting tool according to one of the claims 1 to 11, characterised in that the surface profile of the jacket wall inner surface (4a) and the surface profile of the jacket wall outer surface (4b) along the axial direction has <sic. have> obtuse edges (8) of at least 120° or respectively directional changes of the surface tangents (d or respectively e) of at most 60°.
13. Cutting tool according to one of the claims 1 to 12, characterised in that it has a push rod which extends through a push rod opening (10) of the base body (2) and/or is borne therein, and which is axially movable back and forth in the interior of the prism-shaped hollow body (3), so that cut-out wall sections contained in the interior (11) of the hollow body (3) are able to be expelled out of the hollow body.
14. Cutting tool according to one of the claims 1 to 13, characterised in that in addition to a front opening there is an outlet opening so that cut-out wall sections previously received, and possibly stacked, in the interior (11) of the prism-shaped hollow body (3) are able to be expelled over cut-out wall sections moving into the hollow body later.
15. Cutting tool according to one of the claims 1 to 14, characterised in that the prism-shaped hollow body has an expanded cross section in a portion (4c) of its inner wall along its axial direction.

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