Abstract:
The application comprises a blank for producing a cutting tool with at least one inner bore for conducting fluids, wherein the blank comprises at least a first and a second portion along, its longitudinal axis, wherein the inner bore in the first portion is formed substantially in a straight line and parallel to the longitudinal axis of the blank, and the inner bore in the second portion has a first twist with a first twist angle greater than zero, wherein the blank can be obtained by a continuous pressing operation, in particular a continuous extruding operation. The application also describes an extrusion device for producing a blank, wherein the extrusion device comprises a control element for controlling the twist angle, in particular the first and/or second twist angle.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a blank for producing a cutting tool. Moreover, the present invention relates&#39;to an extrusion device and a method for producing this blank. The present invention further relates to a tool with cooling channels and a tool for the machining of a workpiece. 
     BACKGROUND TO THE INVENTION 
     It is prior art to produce hard metal blanks by means of an extrusion method, wherein the blanks are provided with inner bores during the pressing operation. The inner bores serve as channels for conveying coolant and/or lubricant to the cutting part of the tool. The inner bores of a blank can be formed helically, wherein the inner bores and the flutes of the finished tool also formed helically have to be formed so as to match one another. 
     SUMMARY OF THE INVENTION 
     The helically formed inner bores lead to a higher flow resistance for the coolant and/or lubricant to be conveyed in the inner bores. For this reason, the quantity of coolant and/or lubricant that can be fed per unit of time to the cutting zone of the cutting tool proves to be less compared to rectilinearly run inner bores. This leads to shorter service lives and/or to lower cutting speeds on account of poorer cooling and/or poorer removal of the chips. 
     It can therefore be regarded as a problem of the present invention to make available blanks with inner bores that enable longer service lives and higher cutting speeds of the cutting tool. 
     This problem is solved in the independent claims. Further advantageous embodiments of the invention emerge from the dependent claims. 
     As a first embodiment of the invention, a blank for producing a cutting tool with at least one inner bore for conducting fluids is made available, wherein the blank comprises at least a first and a second portion along its longitudinal axis, wherein the inner bore in the first portion is formed substantially rectilinear and parallel to the longitudinal axis of the blank, and the inner bore in the second portion has a first twist with a first twist angle greater than zero, wherein the blank can be obtained by a continuous pressing operation, in particular a continuous extruding operation. The fluid can be coolant, lubricant, drilling water, cooling lubricant and/or an oil/air mixture, with which minimum quantity lubrication is enabled. 
     The blank, also referred to as a preform, arises through an extruding operation. During the pressing operation, the blank is provided here with inner bores, also referred to as cooling channels, inner channels or simply channels. According to the invention, these inner bores run in a first region rectilinearly and parallel to the longitudinal axis of the blank. Substantially rectilinear and parallel to the longitudinal axis of the blank is understood here to mean that, due to manufacturing tolerances, the inner bores may also run partially non-rectilinearly and/or not parallel to the longitudinal axis of the blank. In a further portion or region of the blank, the inner bores have a twist. Overall, therefore, a blank is present which comprises one (or more) rectilinear inner bore(s) in a first portion and wherein, moreover, the same inner bore (the same inner bores) is (are) formed helically or spirally in a further portion. The portion with the rectilinearly run inner bore can be used as a shank for the cutting tool, whilst the portion with the helically formed inner bore is suitable as the cutting part of the tool. The overall region in which a helical formation of the inner bore is present can thus be reduced, as a result of which the flow resistance for the fluid conveyed in the inner bore is reduced. A greater quantity of the fluid capable of being conveyed in the inner bore results from this, so that a longer service life and/or higher cutting speed of the cutting tool results. The first twist angle can for example have a value in the range from 10 to 60 degrees. 
     As a second embodiment of the invention, an extrusion device for producing a blank according to any one of claims  1  to  15  is made available, wherein the extrusion device comprises a control element for controlling the twist angle, in particular the first and/or second twist angle. 
     The extrusion device is used to press out the blank, the blank being provided with inner bores during the pressing-out. The aim with the production of blanks is to produce blanks with reproducibly identical geometries of the inner bores. Furthermore, the portion of the blank with the helically formed inner bore should be as short as possible in order to keep the flow resistance as low as possible. On the other hand, the portion with the rectilinearly run inner bore must not project into the working, cutting part of the tool, because otherwise there is the risk of the inner bore being interrupted or of the walls of the cutting part of the tool turning out to be too thin, which can drastically shortened the service lives. An exact control is therefore required in order to ensure that rectilinearly run inner bores are present only in the region of the shank. This is ensured by the control element according to the invention. 
     As a third embodiment of the invention, a method for producing a blank according to any one of claims.  1  to  5  is made available, comprising the steps of pressing, in particular extruding, a first portion of the blank, in which the inner bore is formed substantially rectilinear and parallel to the longitudinal axis of the blank, and pressing, in particular extruding, a second portion of the blank, in which the inner bore is formed with a first twist and a first twist angle with a value greater than zero. 
     In accordance with the method according to the invention, two portions are formed inside a blank. These two portions differ by the different formation of the inner bore. In a first portion, the inner bore runs substantially rectilinear. In a further, second portion, the same inner bore experiences a twist with a twist angle. The twist angle is greater than zero and can for example have a value from the range from 10 degrees to 60 degrees. 
     As a fourth embodiment of the invention, a tool is made available for the machining of a workpiece, wherein the tool comprises a flute and a clamping shank, wherein the tool comprises a first region with a first spiral angle of the flute and a second region with a second spiral angle of the flute, wherein the first spiral angle is formed differently from the second spiral angle and/or wherein a third region is disposed between the first region and the second region, wherein in the third region the spiral angle of the flute in the boundary region to the first region is the same as the first spiral angle and in the boundary region to the second region is the same as the second spiral angle. 
     A blank is made available according to an exemplary embodiment of the invention, wherein the blank comprises a third portion along the longitudinal axis of the blank, wherein the third portion is disposed between the first portion and the second portion, wherein in the third portion the inner bore adjacent to the first portion does not have a twist, and adjacent to the second portion has a second twist with a second twist angle, wherein the second twist angle and the first twist angle are the same. An arbitrary, but in particular a constant continuous transition between the first portion and the second portion is thus enabled. 
     A blank is made available according to a further example of embodiment of the invention, wherein in the third portion the inner bore comprises a twist with a twist angle which continuously changes along the longitudinal axis of the blank. 
     A blank is made available, which comprises in an intermediate region an inner bore with a twist and a twist angle, the value whereof continuously changes. A gradual transition between two regions with difference twist angles can thus be created, as a result of which the flow resistance of the inner bore can be further reduced. 
     A blank is made available in a further embodiment according to the invention, wherein the first portion comprises roughly half of the blank. It is thus possible to produce a cutting tool which in the first place, despite the long shank, has a very low flow resistance of the fluid in the inner bore, since the inner bores are formed rectilinear in the shank, and on the other hand offers a large contact area for the clamping chuck, as a result of which a particularly good guidance of the cutting tool and therefore a good transfer of force from the clamping chuck to the cutting tool is enabled. 
     A blank is made available according to an exemplary embodiment of the invention, wherein the first twist angle has a value between 10 and 45 degrees, in particular 15, 20, 30 or 40 degrees. 
     A blank is made available according to a further example of embodiment of the present invention, wherein the blank comprises two or three inner bores. By making available further additional inner bores, the quantity of coolant and/or lubricant that is conveyed through the inner bores to the cutting part of the tool can be increased. The service life and/or the cutting speed of the cutting tool are thus increased. 
     A blank is made available in a further embodiment according to the invention, wherein the blank is made of hard material or ceramic. 
     A blank is made available according to an exemplary embodiment of the invention, wherein the blank has a homogeneous structure, i.e. the blank is as if “from one casting”. Despite an inner structure of the at least one inner bore that differs in sections, the blank does not have any fractures or irregularities or jointing points. A uniformly high loading capacity over the whole length of the blank is thus ensured, which increases the service life. Discontinuities, irregularities or edges at the wall of the inner bore are completely avoided or at least reduced. Without the aforementioned discontinuities, undesired eddies occurring especially in the case of oil/air mixtures are avoided at these points. In particular, the flow rate of oil/air mixtures that are conveyed, through the inner bore can thus be increased. 
     A blank is made available according to a further example of embodiment of the present invention, wherein the inner bore is suitable for conducting coolants and/or lubricants. The coolant and/or the lubricant can for example be drilling water and/or an oil/air mixture and/or a cooling lubricant and/or another suitable means for cooling and/or lubricating the tool. 
     A tool for the machining of a workpiece is made available according to a further exemplary embodiment of the present invention, wherein the tool comprises a blade, wherein the tool comprises a flute for conveying chips and/or coolant and/or lubricant, wherein the tool can be produced from a blank according to any one of claims  1  to  5 . 
     An extrusion device is made available in a further embodiment according to the invention, wherein the control element is suitable for changing the twist angle, in particular the first and/or second twist angle, according to the position along the longitudinal axis of the blank. 
     The control element comprises a means for ascertaining the currently pressed position of the blank and can ascertain, by comparison with a preset nominal geometry of the inner bore, the formation that the inner bore is to continue to acquire. With the possibility of taking action on the extrusion device, the control element can ensure that the preset nominal geometry of the inner bore continues to be produced dimensionally accurately. 
     A method is made available according to an exemplary embodiment of the invention, wherein a third portion is pressed, in particular extruded, between the pressing, in particular extrusion, of the first portion and the pressing, in particular extrusion, of the second portion, wherein in the third portion the inner bore adjacent to the first portion has no twist, and adjacent to the second portion has a second twist with a second twist angle, wherein the second twist angle and the first twist angle are the same. 
     A method is made available according to a further exemplary embodiment of the present invention, wherein the twist angle in the third portion changes continuously along the longitudinal axis of the blank. 
     A method is made available according to a further embodiment according to the invention, wherein the blank comprises two or three inner bores. 
     A tool is made available in a further embodiment according to the invention, wherein the first region extends over a half, a whole, one and half times or two times the diameter of the tool, wherein the third region extends over a half, a whole, one and half, two times, two and a half times, three times, three and a half times, four times or four and a half times the diameter of the tool and wherein the second region occupies the remaining tool and/or wherein the first spiral angle has a number of degrees between 5° and 50°, in particular 30°, and/or wherein the second spiral angle has a number of degrees between 5° and 50°, in particular 15°. 
     A tool is made available according to a further example of embodiment of the present invention, wherein the tool comprises a coolant channel, wherein the coolant channel has a constant twist angle over the whole length of the tool or wherein the coolant channel has a constant twist angle over the whole length except in the region of the clamping shank and/or wherein the tool can be produced from a blank according to any one of claims  1  to  5 . 
     A subject-matter of the invention can be regarded as making available a blank with a reduced flow resistance inside the inner bore by means of an inner bore run as rectilinearly as possible, wherein the inner bore is formed for the most part rectilinear at least in the first portion, i.e. usually the region subsequently used as the shank. 
     The individual features can of course also be combined with one another, as a result of which advantageous effects can in part also appear that go beyond that the sum total of the individual effects. 
     This and other aspects of the present invention are explained and illustrated by reference to the exemplary embodiments described below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments are described below by reference to the following drawings. In the figures: 
         FIG. 1  shows a blank with two inner bores in a longitudinal section, 
         FIG. 2  shows a blank with two inner bores in a cross-section, 
         FIG. 3  shows a blank with two inner bores in a longitudinal section, 
         FIG. 4  shows a blank and an extrusion device, 
         FIG. 5  shows a blank, an extrusion device and a control, 
         FIG. 6  shows a tool with cooling channels, 
         FIG. 7  shows a further tool with cooling channels, 
         FIG. 8  shows a tool according to the invention, 
         FIG. 9  shows an end face of a tool according to the invention, 
         FIG. 10  shows a blank for producing a tool according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a blank  101 , also referred to as a preform, in a longitudinal section, wherein inner bores  102 ,  103  of blank  101  are represented diagrammatically. In a first portion  109 , which extends from a parting line  105  up to a parting line  107 , inner bores  102 ,  103  are formed rectilinear. Inner bores  102 ,  103  run in this portion  109  parallel to longitudinal axis  104  of blank  101 . Inner bores  102 ,  103 , which can also be referred to as cooling channels or simply as channels, run inside blank  101  and convey fluids from the shank to the cutting, working part of the finished drill which is produced from blank  101 . Portion  109  represents the shank in the finished cutting tool, e.g. a drilling tool or milling cutter (e.g. thread milling cutter). The clamping chuck, drill chuck and drill can be accommodated on this shank. Around parting line  105  is a transition region inside blank  101 . The inter-twisting of inner bores  102 ,  103  running non-rectilinearly and parallel to the longitudinal axis in first portion  109  begins in this portion. This transition region can theoretically be constituted as an area almost without width or as a third portion in which inner bores  102 ,  103  gradually twist into one another, wherein no twist is present adjacent to portion  109  and, in the direction towards portion  108 , the twist has an increasing twist angle until the twist angle has a value which corresponds to the value of the twist angle of the twist of inner bores  102 ,  103  in portion  108 . Over a certain length along the longitudinal axis of blank  101  in the transition region, inner bores  102 ,  103  can also have a constant twist angle or even an initially diminishing twist angle in the direction towards portion  108 . Portion  108  begins at parting line  106  and can end at parting line  105 , unless the third portion extends into second portion  108 . In this case, a third portion arises in blank  101  beside the first and the second portion. Blank  101  comprises two inner bores  102 ,  103 . The blank could however also comprise only one bore  102 ,  103  or three, four or more inner bores  102 ,  103 . The dimensioning represents only an example of a specific embodiment, wherein inner bores  102 ,  103  in second portion  108  have here a twist with a twist angle of, in each case, 30 degrees. The twist angle could however also be 15 degrees, 20 degrees, 30 degrees, 40 degrees or another degree value in the range from degrees to 80 degrees, in particular 10 degrees to 45 degrees. The twist angle of inner bores  102 ,  103  can also differ from one another. 
       FIG. 2  shows a blank  101  in cross-section. Circle  201  represents the outer boundary of the blank. The two inner bores  202 ,  203  are located on circle  204 . The dimensional data of  FIG. 2  represent only a possible embodiment of the blank. The blank is represented in  FIG. 2  enlarged fivefold (5:1). 
       FIG. 3  shows a blank  301  with a first portion  309  and a second portion  308 . First portion  309  extends from one end  307  of blank  301  up to parting line  305 . This first portion  309  represents the shank in the finished cutting tool, e.g. a drill or milling cutter. Second portion  308  extends from the other end  306  of blank  301  up to parting line  305 . Inner bores  302 ,  303  run in the first portion rectilinearly and parallel to longitudinal axis  304  of blank  301 . In second portion  308 , which can extend from parting line  306 , which represents the end of the blank, up to parting line  305 , inner bores  302 ,  303  no longer run rectilinearly and parallel to longitudinal axis  304  of blank  301 . In the second portion, the inner bores are twisted into one another, i.e. the inner bores are formed helically or spirally. This helical formation of inner bores  302 ,  303  is necessary in order to evade the flutes of the finished tool, in order that the inner bores are not interrupted along longitudinal axis  304  and do not come too close to the outer wall of the tool. The inner bores serve to convey coolant, lubricant, drilling water, cooling lubricant and/or an air/oil mixture to the front part of the cutting tool. In the case of a drill, the drill bit can be supplied with coolant through inner bores  302 ,  303 . The coolant emerging from the inner bores is conveyed out via the flutes together with the occurring chips from the bore hole. Apart from coolant or lubricant, the inner bores can also convey an air/oil mixture (or oil/air mixture) to the front cutting part of the cutting tool, as a result of which minimum quantity lubrication is enabled. It is especially advantageous to provide the first portion with rectilinear inner bores  302 ,  303 , because in this way the flow resistance of the conveyed fluid (coolant, lubricant, air/oil mixture, cooling lubricant, drilling water) can be reduced. 
     A lower flow resistance thus arises for the whole blank, as a result of which a higher flow rate of the fluid can be achieved inside the finished cutting tool. Better cooling, since it is at a higher rate, and more rapid removal of the chips is achieved via the flutes, as a result of which the service lives can be increased and/or the operating speed of the cutting tool, on account of the increase in the rotational speed of the tool, can be increased. 
       FIG. 4  shows a blank  401  in a longitudinal section with two inner bores  402 ,  403 , wherein in a first portion, which extends from parting line  406  up to parting line  405 , inner bores  402 ,  403  are formed rectilinear and parallel to longitudinal axis  404 . In a second portion, which extends from parting line  405  up to parting line  407 , inner bores  402 ,  403  have a twist with a twist angle greater than zero. At parting line  405 , the twist can start here initially with a smaller twist angle and, extending into the second portion, can have a twist with an increasing twist angle. The second portion comprises a sub-section, which extends from end  407  of blank  401  up to just short of parting line  405  and has an approximately constant twist angle of inner bores  402 ,  403 . The region between the second portion, which comprises inner bore  402 ,  403  with a changing twist angle, can be referred to as the third portion beside the first and the second portion. Blank  401  is formed by the processing of an extrusion material with the aid of an extrusion device  408 . Extrusion device  408  comprises an inlet  409 , which receives the raw extrusion material, and an outlet  410 , from which the blank is pressed, and more precisely extruded. Extrusion device  408  comprises elements for forming inner bores  402 ,  403  of blank  401 , wherein extrusion device  408  is capable of providing inner bores  402 ,  403  along longitudinal axis  404  of the blank with different twists, i.e. with twists with different twist angles. Blanks  401  can thus arise, inner bore  402 ,  403  whereof has a twist, the twist angle whereof continuously changes or the twist angle whereof is constant over individual regions or the twist angle whereof in other regions has a value of approximately zero. 
       FIG. 5  shows a blank  501  with a first portion, which extends from parting line  506  up to parting line  505 , wherein in this portion inner bores  502 ,  503  run rectilinearly and moreover parallel to longitudinal axis  504  of blank  501 . It is also conceivable that inner bores  502 ,  503  do not run parallel to longitudinal axis  504  of blank  501 , but do run rectilinearly. It is also conceivable that inner bores  502 ,  503  run neither parallel to longitudinal axis  504  nor rectilinearly, but are also not formed helically. A transition region can exist around parting line  505 , in which inner bores  502 ,  503  transform into twisted inner bores  502 ,  503  of the second portion. This transition region can be regarded as the third portion. It is also conceivable that no transition region is present. In this case, rectilinear inner bores  502 ,  503  of the first portion transform directly into twisted inner bores  502 ,  503  of the second portion without a gradual twist adaptation taking place. In this case, the second portion extends from parting line  505  up to parting line  507 . Blank  501  is produced by extrusion by means of an extrusion device  508 . A raw material is introduced here into inlet  509  in the extrusion device and the blank is pressed out from outlet  510 . The control of the twist, i.e. what twist angle the twist of inner bore  502 ,  503  should have at what position along longitudinal axis  504  of blank  501 , takes place by means of control element  513 . Control element  513  controls extrusion device  508  via a control path  512  and receives information concerning the current longitudinal position, i.e. the position of blank  501  along its longitudinal axis  504 , via a signal path  511 . Blanks  501  with an identical twist distribution of inner bores  502 ,  503  over their longitudinal axis  504  can be produced reproducibly by means of this control loop. 
       FIG. 6  shows a tool  601 , e.g. a drill, with two inner bores (cooling channels)  602 ,  603 , wherein the tool comprises a blade  611  and at least one flute  610 . Flute  610  can end before the first portion, the shank,  609  or in the front region of shank  609 , in order that the conveyed chips can be ejected before the region of shank  609  clamped in the tool chuck. 
       FIG. 7  shows a tool  701 , e.g. a drill, with a blade  711  and a flute  710 . 
     The advantage of the invention is also to be seen in the fact that blanks can be produced with inner bores which can each have a twist with different twist angles, and moreover in a straightforward manner by extrusion. In particular, the production operation does not have to be interrupted in order for example to fit together sections with different twist angles. This thus leads to higher productivity. Furthermore, the use of solder to produce a solder joint or soldered joint is avoided, as a result of which an additional work step can be dispensed with, which leads to speeding-up of the production process, or a required welding operation is dispensed with. 
     The production of a cutting tool, e.g. drill, milling cutter, in particular thread milling cutter, requires helical inner bores, since the inner bores must not run into the flutes. Otherwise, the inner bores would be interrupted and the fluids to be conveyed, in particular coolant, lubricant, oil and/or air, would not get to the, in particular, cutting regions of the cutting tool. The helical formation of the inner bores is also necessary in order that the outer walls do not become too thin in the cutting part of the tool, which would lead to the service life being dramatically reduced. A drawback, however, is that the flow resistance is increased on account of the helical formation of the inner bores. The invention advantageously comprises inner bores that run rectilinearly in the shank, as a result of which the flow resistance proves to be much less than in the case of inner bores which have a helical formation of the inner bores over the whole length of the cutting tool, i.e. also in the shank region. 
     The invention enables here the production of blanks comprising one piece which have advantageous flow characteristics, without a plurality of parts having to be fitted together, e.g. parts with helical inner bores and parts with rectilinear inner bores. A shorter production time of the blanks is thus enabled. Moreover, the blanks thus have a homogeneous structure, which leads to a higher loading capacity of the produced cutting tools, as a result of which a longer service life and/or higher path feed rate can be achieved. 
     On account of the inventive production of the blanks “from one casting”, there is no need for the flush matching of the inner bores of parts to be fitted together. A time-consuming and labour-intensive production process is thus avoided as a result. 
     Reproducible blanks with identical geometries of the inner bores can be produced by means of the control element according to the invention. The reject rate is thus reduced. 
       FIG. 8  shows a tool according to the invention with a first portion or region with a first spiral angle or spiral pitch progression of one or more flutes  803 , wherein the spiral angle can be formed constant in the first region. The tool comprises a third portion with a changing spiral angle and a second portion with a second spiral angle of the flute or the flutes, wherein the second spiral angle can be formed constant over the length of the second portion. In an exemplary embodiment of the invention, the first spiral angle can have a number of degrees between 5° and 50°, in particular 30°, the spiral angle in the third portion can diminish continuously, in particular from 30° to 15°, and the second spiral angle can have a constant value in the range between 5° and 50°, in particular 15°. In a further embodiment, the first portion can extend over a length of a half, a whole, one and half times, two times, two and a half times, three times, three and a half times, four times or four and a half times the diameter of the tool, the third portion over a length of a half, a whole, one and half times, two times, two and a half times, three times, three and a half times, four times or four and a half times the diameter of the tool and the second portion occupies the remaining region of the tool. In a further embodiment, the tool can comprise one or more coolant channels, wherein these coolant channels can have a constant twist angle over the whole length of the tool. In a further alternative embodiment, the tool can comprise one or more coolant channels which, in the region of clamping shank  801 , have a constant twist angle, e.g. 0°, and in the remaining region of the tool another constant twist angle, e.g. 15°. In an alternative embodiment, the tool according to the invention can comprise only a first portion and a second portion and no third portion. With this variant, therefore, the tool according to the invention has an abrupt transition, i.e. not a gradual transition, of the first spiral angle to the second spiral angle. 
       FIG. 9  shows an end face of a tool according to the invention with two outlet openings  901 ,  902  of two coolant channels. Alternatively, the tool according to the invention can comprise only one coolant channel or arbitrarily many coolant channels. 
       FIG. 10  shows a blank for producing a tool according to the invention with a region  1002 , which can be provided as a clamping shank, and a tip  1003 , which can be formed into a tool bit. 
     It should be noted that the term “comprise” does not exclude further elements or process steps, just as the term “a” or “an” does not exclude a plurality of elements or steps. 
     The employed reference numbers serve merely to increase comprehensibility and should under no circumstances be regarded as limiting, the scope of protection of the invention being reproduced by the claims. 
     List Of Reference Numbers 
     
         
           101  blank, 
           102  inner bore, 
           103  inner bore, 
           104  longitudinal axis, 
           105  parting line, 
           106  parting line, 
           107  parting line, 
           108  second portion, 
           109  first portion, 
           201  blank, 
           202  inner bore, 
           203  inner bore, 
           301  blank, 
           302  inner bore, 
           303  inner bore, 
           304  longitudinal axis, 
           305  parting line, 
           306  parting line, 
           307  parting line, 
           308  second portion, 
           309  first portion, 
           401  blank, 
           402  inner bore, 
           403  inner bore, 
           404  longitudinal axis, 
           405  parting line, 
           406  parting line, 
           407  parting line, 
           408  extrusion device, 
           409  inlet, 
           410  outlet, 
           501  blank, 
           502  inner bore, 
           503  inner bore, 
           504  longitudinal axis, 
           505  parting line, 
           506  parting line, 
           507  parting line, 
           508  extrusion device, 
           509  inlet, 
           510  outlet, 
           511  signal path, 
           512  control path, 
           513  control element 
           601  tool 
           602  cooling channel, 
           603  cooling channel, 
           604  longitudinal axis, 
           605  parting line, 
           606  parting line, 
           607  parting line, 
           608  second portion, 
           609  first portion, 
           610  flute, 
           611  blade, 
           701  tool, 
           702  cooling channel, 
           703  cooling channel, 
           704  longitudinal axis, 
           705  parting line, 
           706  parting line, 
           707  parting line, 
           708  second portion, 
           709  first portion, 
           710  flute, 
           711  blade, 
           801  clamping shank, 
           802  centre line 
           803  flute, 
           804  tool bit, 
           901  outlet opening coolant channel, 
           902  outlet opening coolant channel, 
           1001  centre line 
           1002  clamping shank, 
           1003  tool bit.