Tools, machines, and methods for machining planar workpieces
11376647 · 2022-07-05
Assignee
Inventors
- Marc Klinkhammer (Ditzingen, DE)
- Dennis Traenklein (Nufringen, DE)
- Markus Wilhelm (Gerlingen, DE)
- Rainer Hank (Eberdingen/Hochdorf, DE)
- Leonard Schindewolf (Rutesheim, DE)
- Simon Ockenfuss (Boeblingen, DE)
- Jens Kappes (Leinfelden-Echterdingen, DE)
- Alexander Tatarczyk (Hoeffingen, DE)
- Joerg Neupert (Stuttgart, DE)
- Dominik Bitto (Muenchingen, DE)
- Markus Maatz (Leinfelden-Echterdingen, DE)
- Christian Jakisch (Boeblingen, DE)
Cpc classification
Y10T83/8733
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B21D28/34
PERFORMING OPERATIONS; TRANSPORTING
Y10T83/8732
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B26F2001/4427
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
Tools for machining planar workpieces are provided that include an upper tool, an upper main body, and at least one tool body on the upper main body having a cutting edge. The tools further include a lower tool having a lower main body with a rest surface for the workpiece and a positioning axis oriented perpendicular to the rest surface, at least one counter tool body on the lower main body that has a counter cutting edge that is a closed contour. The cutting edge of the at least one tool body has a cutting contour that corresponds to the closed contour of the at least one counter tool body, and at least one group of at least two counter tool bodies on the lower tool can be associated with the closed contour of the least one tool body.
Claims
1. A tool for machining planar workpieces, comprising: an upper tool having a clamping shaft and an upper main body that lie on a common upper positioning axis; at least one tool body arranged on the upper main body opposite the clamping shaft, wherein the tool body has a cutting edge; a lower tool having a lower main body with a rest surface for the workpiece and a lower positioning axis oriented perpendicular to the rest surface; and at least one group of at least two counter tool bodies arranged on the lower main body and each comprising respective counter cutting edges, wherein the at least two counter tool bodies of the at least one group lie outside of an imaginary circle in the rest surface of the lower tool, wherein the circle is concentric to the lower positioning axis at a distance from the lower positioning axis that is smaller than a distance from the lower positioning axis to the at least two counter tool bodies of the at least one group, wherein the cutting edge of the at least one tool body has a cutting contour that corresponds to counter cutting contours of the counter cutting edges of the group of at least two counter tool bodies, wherein the at least one group of at least two counter tool bodies on the lower tool can be associated with the cutting contour of the at least one tool body via a traversing movement perpendicular or inclined to the upper positioning axis of the upper tool or the lower positioning axis of the lower tool, or both, or by a combination of the traversing movement perpendicular or inclined to the upper or lower positioning axis and by a rotary movement about the upper positioning axis of the upper tool or the lower positioning axis of the lower tool, or both, and wherein, in the at least one group, the counter cutting contour of a first counter tool body corresponds to the cutting contour of the at least one tool body with a first cutting gap width and the counter cutting contour of a second or further counter tool body corresponds to the cutting contour of the at least one tool body with a second or further cutting gap width.
2. The tool of claim 1, wherein the at least one group of counter tool bodies is insertable in the lower main body each individually on a main body insert or together on a main body insert.
3. The tool of claim 2, wherein the main body insert is rotatable with respect to the main body of the lower tool.
4. The tool of claim 1, wherein the upper tool comprises a multi-tool and has at least two tool bodies each having a cutting edge and a cutting contour, and wherein the lower tool has at least two groups of counter tool bodies.
5. A tool for machining planar workpieces, comprising: an upper tool having a clamping shaft and an upper main body that lie on a common upper positioning axis; at least one tool body arranged on the upper main body opposite the clamping shaft, wherein the tool body has a cutting edge; a lower tool having a lower main body with a rest surface for the workpiece and a lower positioning axis oriented perpendicular to the rest surface; and at least one group of at least two counter tool bodies arranged on the lower main body and each comprising respective counter cutting edges, wherein the cutting edge of the at least one tool body has a cutting contour that corresponds to counter cutting contours of the counter cutting edges of the group of at least two counter tool bodies, wherein the at least one group of at least two counter tool bodies on the lower tool can be associated with the cutting contour of the at least one tool body via a traversing movement perpendicular or inclined to the upper positioning axis of the upper tool or the lower positioning axis of the lower tool, or both, or by a combination of the traversing movement perpendicular or inclined to the upper or lower positioning axis and by a rotary movement about the upper positioning axis of the upper tool or the lower positioning axis of the lower tool, or both, wherein, in the at least one group, the counter cutting contour of a first counter tool body corresponds to the cutting contour of the at least one tool body with a first cutting gap width and the counter cutting contour of a second or further counter tool body corresponds to the cutting contour of the at least one tool body with a second or further cutting gap width, and wherein the first and at least one further group of counter tool bodies do not lie on an imaginary circle in the rest surface of the lower tool, wherein the circle is concentric to the lower positioning axis at a distance from the lower positioning axis that is smaller or larger than a distance from the lower positioning axis to the first and the at least one further group of counter tool bodies.
6. A processing machine for machining planar workpieces, comprising: an upper tool having a clamping shaft and an upper main body and that is moveable along an upper stroke axis by a stroke drive device in a direction towards or away from a workpiece to be processed by the upper tool, and that is positionable along an upper horizontal positioning axis running perpendicular to the upper stroke axis; an upper drive assembly configured to displace the upper tool along the upper positioning axis; a lower tool having a lower main body with a rest surface for the workpiece and that is moveable along a lower stroke axis by a stroke drive device in the direction of the upper tool, and that is positionable along a lower horizontal positioning axis oriented perpendicular to the upper stroke axis of the upper tool and oriented perpendicular to the rest surface; a lower drive assembly configured to displace the lower tool along the lower positioning axis; a controller configured to control the upper and lower drive assemblies and to control a traversing movement of the upper tool along the upper horizontal positioning axis and a traversing movement of the lower tool along the lower horizontal positioning axis independently of each other; at least one tool body arranged on the upper main body opposite the clamping shaft, wherein the tool body has a cutting edge; and at least one group of at least two counter tool bodies arranged on the lower main body and each comprising respective counter cutting edges, wherein the at least two counter tool bodies of the at least one group lie outside of an imaginary circle in the rest surface of the lower tool, wherein the circle is concentric to the lower positioning axis at a distance from the lower positioning axis that is smaller than a distance from the lower positioning axis to the at least two counter tool bodies of the at least one group, wherein the cutting edge of the at least one tool body has a cutting contour that corresponds to counter cutting contours of the counter cutting edges of the group of at least two counter tool bodies, wherein the at least one group of at least two counter tool bodies on the lower tool can be associated with the cutting contour of the at least one tool body via a traversing movement perpendicular or inclined to a vertical positioning axis of the upper tool or lower tool or both, or by a combination of the traversing movement perpendicular or inclined to the vertical positioning axis and by a rotary movement about the upper vertical positioning axis of the upper tool or lower vertical positioning axis of the lower tool, or both, and in the at least one group, the counter cutting contour of a first counter tool body corresponds to the cutting contour of the at least one tool body with a first cutting gap width and the counter cutting contour of a second or further counter tool body corresponds to the cutting contour of the at least one tool body with a second or further cutting gap width.
7. The machine tool of claim 6, wherein at least one of the upper tool and lower tool is positionable relative to the other by a traversing movement along the respective upper horizontal positioning axis or lower horizontal positioning axis, or both; by a traversing movement along the upper vertical positioning axis or the lower vertical positioning axis, or both; or by a rotary movement about the upper vertical positioning axis or the lower vertical positioning axis, or both.
8. A method for machining planar workpieces, the method comprising: obtaining a tool that comprises: an upper tool having a clamping shaft and an upper main body that lie on a common upper vertical positioning axis; at least one tool body arranged on the upper main body opposite the clamping shaft, wherein the tool body has a cutting edge; a lower tool having a lower main body with a rest surface for the workpiece and a lower vertical positioning axis oriented perpendicular to the rest surface; and at least one group of at least two counter tool bodies arranged on the lower main body and each comprising respective counter cutting edges, wherein the at least two counter tool bodies of the at least one group lie outside of an imaginary circle in the rest surface of the lower tool, wherein the circle is concentric to the lower positioning axis at a distance from the lower positioning axis that is smaller than a distance from the lower positioning axis to the at least two counter tool bodies of the at least one group, wherein the cutting edge of the at least one tool body has a cutting contour that corresponds to counter cutting contours of the counter cutting edges of the group of at least two counter tool bodies, wherein the at least one group of at least two counter tool bodies on the lower tool can be associated with the cutting contour of the at least one tool body via a traversing movement perpendicular or inclined to the upper vertical positioning axis of the upper tool or the lower vertical positioning axis of the lower tool, or both, or by a combination of the traversing movement perpendicular or inclined to the upper or lower vertical positioning axis and by a rotary movement about the upper vertical positioning axis of the upper tool or the lower vertical positioning axis of the lower tool, or both, and in the at least one group, the counter cutting contour of a first counter tool body corresponds to the cutting contour of the at least one tool body with a first cutting gap width and the counter cutting contour of a second or further counter tool body corresponds to the cutting contour of the at least one tool body with a second or further cutting gap width; moving the upper tool along a stroke axis by a stroke drive device in a direction towards or away from a workpiece to be processed by the upper tool, wherein the upper tool is positionable along an upper horizontal positioning axis running perpendicular to the stroke axis, and is displaceable by an upper drive assembly along the upper horizontal positioning axis; moving the lower tool along a lower stroke axis by a stroke drive device in the direction of the upper tool, wherein the lower tool is positionable along a lower horizontal positioning axis oriented perpendicular to the stroke axis of the upper tool, and is displaceable by a lower drive assembly along the lower horizontal positioning axis; providing a controller to actuate the upper and lower drive assemblies to move the upper and lower tools; and using a tool to process the workpieces.
9. The method of claim 8, wherein the tool body of the upper tool and the counter tool body of the lower tool are oriented relative to one another at least by a traversing movement along the upper or lower horizontal positioning axis or both or by a rotary movement of the upper tool or of the lower tool both about their respective vertical positioning axes.
10. The method of claim 8, wherein, in an upper tool configured as a multi tool, one of the tool bodies on the upper tool is chosen for the subsequent machining operation by actuation of an activating device.
Description
DESCRIPTION OF DRAWINGS
(1) The invention and further advantageous embodiments and developments thereof will be described and explained in greater detail hereinafter with reference to the examples shown in the drawings. The features inferred from the description and the drawings can be applied in accordance with the invention individually or in any combination.
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DETAILED DESCRIPTION
(12)
(13) The processing machine 1 is used to machine planar workpieces 10 that for the sake of simplicity have not been shown in
(14) The upper tool 11 and lower tool 9, instead of being a punch and a die for punching, can also be a bending punch and a bending die for shaping workpieces 10.
(15) The upper tool 11 is fixed in a tool receptacle on a lower end of a ram 12. The ram 12 is part of a stroke drive device 13, by which the upper tool 11 can be moved in a stroke direction along a stroke axis 14. The stroke axis 14 runs in the direction of the Z axis of the coordinate system of a numerical controller 15 of the processing machine 1 indicated in
(16) The movement of the ram 12 along the stroke axis 14 and the positioning of the stroke drive device 13 along the positioning axis 16 are achieved by a motor drive 17 that can be configured in the form of a drive assembly 17, e.g., a spindle drive assembly, with a drive spindle 18 running in the direction of the positioning axis 16 and fixedly connected to the machine frame 2. The stroke drive device 13, in the event of movements along the positioning axis 16, is guided on three guide rails 19 of the upper frame limb 3, of which two guide rails 19 can be seen in
(17) The lower tool 9 is received moveably along a lower positioning axis 25. This lower positioning axis 25 runs in the direction of the Y axis of the coordinate system of the numerical controller 15. The lower positioning axis 25 can be oriented parallel to the upper positioning axis 16. The lower tool 9 can be moved directly on the lower positioning axis 16 by a motor drive assembly 26 along the positioning axis 25. Alternatively or additionally, the lower tool 9 can also be provided on a stroke drive device 27 that is moveable along the lower positioning axis 25 by the motor drive assembly 26. This drive assembly 26 can be configured as a spindle drive assembly. The structure of the lower stroke drive device 27 can correspond to that of the upper stroke drive device 13. The motor drive assembly 26 likewise can correspond to the motor drive assembly 17.
(18) The lower stroke drive device 27 is mounted displaceably on guide rails 19 associated with a lower horizontal frame limb 4. Guide shoes 20 of the stroke drive device 27 run on the guide rails 19, such that the connection between the guide rails 19 and guide shoes 20 at the lower tool 9 can also bear a load acting in the vertical direction. Accordingly, the stroke drive device 27 is also mounted on the machine frame 2 via the guide shoes 20 and the guide rails 19, moreover at a distance from the guide rails 19 and guide shoes 20 of the upper stroke drive device 13. The stroke drive device 27 can also include a wedge gear 21, by which the position or height of the lower tool 9 along the Z axis (e.g., lower stroke axis 30, as shown in
(19) Via the numerical controller 15, both the motor drives 17 for a traversing movement of the upper tool 11 along the upper positioning axis 16 and the one or more motor drives 26 for a traversing movement of the lower tool 9 along the lower positioning axis 25 can be controlled independently of one another. The upper and lower tools 11, 9 are thus moveable synchronously in the direction of the Y axis of the coordinate system. An independent traversing movement of the upper and lower tools 11, 9 in different directions can also be controlled. This independent traversing movement of the upper and lower tools 11, 9 can be controlled simultaneously. As a result of the decoupling of the traversing movement between the upper tool 11 and the lower tool 9, an increased versatility of the machining of workpieces 10 can be attained. The upper and lower tools 11, 9 can also be configured to machine the workpieces 10 in many ways.
(20) One component of the stroke drive device 13 is the wedge gear 21 that is shown in
(21) The output-side double wedge 126 is defined by a wedge surface 130, and by a wedge surface 131 of the output-side gear element 125. Wedge surfaces 132, 133 of the drive-side wedge gear elements 122, 123 are arranged opposite the wedge surfaces 130, 131 of the output-side wedge gear elements 124, 125. By longitudinal guides 134, 135, the drive-side wedge gear element 122 and the output-side wedge gear element 124, and also the drive-side wedge gear element 123 and the output-side wedge gear element 125, are guided moveably relative to one another in the direction of the Y axis, that is to say in the direction of the positioning axis 16 of the stroke drive device 13.
(22) The drive-side wedge gear element 122 has a motor drive unit 138, and the drive-side wedge gear element 123 has a motor drive unit 139. Both drive units 138, 139 together form the spindle drive assembly 17.
(23) The drive spindle 18 shown in
(24) The drive-side wedge gear elements 122, 123 are operated by the motor drive units 138, 139 in such a way that the wedge gear elements move, for example, towards one another along the positioning axis 16, whereby a relative movement is performed between the drive-side wedge gear elements 122, 123 on the one hand and the output-side wedge gear elements 124, 125 on the other hand. As a result of this relative movement, the output-side double wedge 126 and the ram 12 mounted thereon is moved downwardly along the stroke axis 14. The punch mounted on the ram 12 for example as the upper tool 11 performs a working stroke and in so doing machines a workpiece 10 mounted on the workpiece rest 28, 29 or the workpiece support 8. By an opposite movement of the drive wedge elements 122, 123, the ram 12 is in turn raised or moved upwardly along the stroke axis 14.
(25) The above-described stroke drive device 13 of
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(27) The possible stroke movement of the ram 12 on the upper tool 11 shown in the graph in
(28) This exemplary superposed stroke profile can be controlled for both the upper tool 11 and the lower tool 9. Depending on the machining of the workpiece 10 that is to be performed, a superposed stroke movement of the upper tool and/or lower tool 11, 9 can be controlled.
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(31) The further workpiece rest 29 is provided on the machine frame 2 opposite the workpiece rest 28. This further workpiece rest can be associated, for example, with an unloading station. Alternatively, the loading of the unprocessed workpiece 10 and unloading of the machined workpiece 10 having workpieces 81 can also be associated with the same workpiece rest 28, 29.
(32) The processing machine 1 can furthermore include a laser machining device 201, such as the laser cutting machine that is shown schematically in in
(33) The laser cutting head 206 is moveable by a linear drive 207 having a linear axis system at least in the Y direction, or in the Y and Z direction. This linear axis system, which receives the laser cutting head 206, can be associated with the machine frame 2, fixed thereto or integrated therein. A beam passage opening can be provided in the workpiece rest 28 below a working space of the laser cutting head 206. A beam capture device for the laser beam 21 can be provided preferably beneath the beam passage opening 210. The beam passage opening and as applicable the beam capture device can also be configured as one unit.
(34) The laser machining device 201 can alternatively also include a solid-state laser as laser source 202, the radiation of which is guided to the laser cutting head 206 with the aid of a fiber-optic cable.
(35) The workpiece rest 28, 29 can extend to the workpiece support 8 that at least partially surrounds the lower tool 9. Within a resultant free space created therebetween, the lower tool 9 is moveable along the lower positioning axis 25 in and against the Y direction.
(36) On the workpiece rest 28 there lies, for example, a machined workpiece 10, in which a workpiece part 81 has been cut free by a cutting gap 83, for example by punching or by laser beam machining, apart from a remaining connection 82. The workpiece 81 is held in the workpiece 10 or the remaining sheet skeleton by this remaining connection. To separate the workpiece part 81 from the workpiece 10, the workpiece 10 is positioned by the feed device 22 relative to the upper and lower tool 11, 9 for a separation and discharge step. Here, the remaining connection 82 is separated by a punching stroke of the upper tool 11 relative to the lower tool 9. The workpiece part 81 can, for example, be discharged downwardly by partially lowering the workpiece support 8. Alternatively, in the case of larger workpiece parts 81, the cut-free workpiece part 81 can be transferred back again onto the workpiece rest 28 or onto the workpiece rest 29 to unload the workpiece part 81 and the sheet skeleton. Small workpiece parts 81 can also be discharged optionally through an opening in the lower tool 9.
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(38) The lower tool 9 likewise includes a main body 41 for arrangement of the lower tool 9 in the lower tool receptacle on the machine. In this exemplary embodiment of the lower tool 9, the lower tool has a guide 402 by which the main body 31 of the lower tool 9 is moveable along a lower tool receptacle. Alternatively, the main body 41 of the lower tool 9 can be fixedly arranged in the lower tool receptacle and a traversing movement along the arrow in the Y direction within the machine frame 2 controlled by the lower drive assembly 26 along the lower positioning axis 25.
(39) The lower tool 9 has, for example, a group of counter tool bodies 93 that each have a counter cutting edge 51. The counter cutting edge 51 is configured as a closed contour, whereby an opening is formed inside the counter tool body 93. A cutting contour of the tool body 39 is adapted to the closed contour of the counter tool body 93. The counter tool bodies 93, of which three are depicted, arranged in the lower tool 9 have contours 403, 404 and 405 that differ from one another in size. The differences are such that, in relation to the cutting contour of the tool body 37, there is an adjustment of the cutting gap to different material thicknesses for the workpiece 10 to be machined. For example, in the case of a tool body 39 with a width of a cutting contour of 8 mm, the first contour 403 includes a width of 8.1 mm, the second contour 404 a width of 8.2 mm and the third contour 405 a width of 8.4 mm. As a result it is possible, for example, by combining the tool body 39 with the first contour 403 to cut a workpiece 10 (e.g., a metal sheet) with a material thickness of 1 mm, by combining the tool body 39 with the second contour 404 of the counter tool body 93 to cut a metal sheet with a material thickness of 2 mm, and by combining the tool body 39 with the third contour 405 to cut a metal sheet with a material thickness of 4 mm.
(40) Such a tool 31 thus makes it possible that, for example, three different material thicknesses of a workpiece can be machined with only one cutting contour of the tool body 39 on the upper tool 11, without it being necessary to change the tool 31. The lower tool 9 can also include only two or also more than three counter tool bodies 93.
(41) For positioning the upper tool 11 relative to the lower tool 9, the tool body 39 can be oriented relative to the counter cutting edge 93 by a rotary movement about the positioning axis 35. By a traversing movement of the upper tool 11 along the upper positioning axis 16 and/or of the lower tool 9 along the lower positioning axis 25, after the material thickness of the workpiece 10 to be machined has been established the tool body 39 of the upper tool 11, can be moved towards one of the three contours 403, 404 or 405 of the counter tool body 93 in the lower tool 9 and oriented so that the positioning axis 35 of the upper tool 11 and the positioning axis 48 of the lower tool 9 coincide. That is, the tool body 39 and the counter tool body 93 are oriented relative to one another.
(42) The counter tool bodies 93 can be configured as a main body insert 406, so that it is replaceable relative to the main body 41 of the lower tool 9. In the case of wear, simple replacement is made possible. Moreover, the main body insert 406 can be rotatably controllable on the main body 41 of the lower tool 9. The cutting contour of the tool body 39 can in turn be adjusted and oriented relative to the closed contour of the counter cutting edge 51 in the counter tool body 93 by orientation of the upper tool 11.
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(45) The upper tool 11 corresponds to the embodiment in
(46) The lower tool 9 includes a main body 41 and a rest surface 47 on which the workpiece 10 rests during machining. A plurality of counter tool bodies 93 are on the rest surface 47 of the main body 41 of the lower tool 9.
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(48) Associated with one of the tool bodies 39 of the upper tool 11 is a first group 411 of counter tool bodies 93 that have closed contours 403, 404, 405 that differ in size from each other. The difference in size of the contours 403, 404 and 405 within a group 411 adjusts the cutting gap to the material thickness of the workpiece 10 to be machined. The number of different contours is only by way of example. The group can have two or more than three mutually different contours. These closed contours 403, 404, 405 differ from the cutting contour of the first tool body 39 to the effect that there is an adjustment of the cutting gap in relation to different material thicknesses of the workpieces 10 to be machined.
(49) In the lower tool 9 there is, for example, in addition to the first group 411, a second group 412 of counter tool bodies 93 that cooperate with a second tool body 39 on the upper tool 11. This second group 412 of counter tool bodies 93 is, for example, smaller in diameter than the first group 411 of counter tool bodies 93. For example, three contours 413, 414, 415, which differ in size from one another, of the counter tool bodies 93 can form that group for cutting gap adjustment for the same tool body 39. The number of counter tool bodies 93 per group 411, 412 can also differ from one another.
(50) If sufficient free surface is available in the rest surface 47 to form further counter tool bodies 93, a third group 418 of counter tool bodies 93 as well as a plurality of further groups can be provided. Only by way of example, the third group 418 of counter tool bodies 93 again has three mutually different contours 420, 421 and 422 of the counter tool bodies 93. There can also be only two or more than three counter tool bodies 93. This third group 418 of counter tool bodies 93 is associated with the third tool body 39 on the upper tool 11.
(51) Advantageously, the number of contours in at least two groups 411, 412 of counter tool bodies 3 arranged in the lower tool 9 can be equal, so that the same number of different material thicknesses can be machined with that tool 31.
(52) Alternatively, it is also possible that the first group 411 and the at least one further group 412, 418 have numbers of contours on the counter tool body 93 that differ from one another.
(53) The shape and/or geometry of the closed contour of the counter tool bodies 93 of the first group 411 can also differ from that of the second group 412 and/or of the further group 418.
(54) The arrangement of the counter tool bodies 93 in the rest surface 47 of the lower tool 9 can be outside a common circle. The first and at least one further group 411, 412, 418 can also be arranged outside a common circle of the rest surface 47. By controlling a traversing movement of the upper tool 11 and of the lower tool 9 independently of each other, and also by controlling the rotary movement of the upper tool 11 and of the lower tool 9 again independently of each other, it is possible to orient one tool body 37 on the upper tool 11 appropriately for the respective closed contour of the first group 414 or of the further group 412, 418. An arrangement of the counter tool bodies 93 on a circle concentric to the positioning axis 48 and the arrangement of the tool body 39 concentric to the positioning axis 35 is therefore not necessary.
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(56) The first group 411 of counter tool bodies 93 can lie on a circle 425. The at least one further group 412, 418 of counter tool bodies 93 can lie on further circles different from the circle 425 or can also be arranged outside that circle.
OTHER EMBODIMENTS
(57) A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.