WO2009149804A1

WO2009149804A1 - Vacuum roller having suction grooves

Info

Publication number: WO2009149804A1
Application number: PCT/EP2009/003432
Authority: WO
Inventors: Reinhard Raueiser
Original assignee: WINKLER+DüNNEBIER AG
Priority date: 2008-05-29
Filing date: 2009-05-14
Publication date: 2009-12-17
Also published as: DE102008025685A1

Abstract

The invention relates to a vacuum roller (1) for transporting a flat material section, wherein the external surface (2) of the vacuum roller (1) comprises suction holes (3) to which suction air can be applied by means of suction air ducts axially extending inside the roller (1). The roller (1) further comprises multiple suction grooves (4) connecting the suction holes and extending in spirals across the external surface (3). According to the invention, the suction grooves (4) are produced by spirally guiding a shaping device along the external surface (2) of the vacuum roller (1), wherein the shaping device produces a suction groove profile when said device is guided along the external surface (2) in the circumferential direction perpendicular to the roller axis (4), the side walls of said suction groove forming an angle of less than 20° with the external surface (2) of the roller (1) in the transition zone to the external surface (2), when seen in a section perpendicular to the direction of extension of the suction groove.

Description

Vacuum roller with suction grooves

I. Field of application

The invention generally relates to a vacuum roller for transporting flat material blanks and, more particularly, to a vacuum roll for picking up and subsequently transporting flat stock blanks which are fed to the roll in the form of a web of material and separated from the web adjacent the roll, such that the sheet blanks are temporarily slipped rest against the roller.

II. Technical background

For transporting flat material blanks, for example envelope blanks in a letter envelope production machine, so-called vacuum rolls are frequently used. A vacuum roller in this case has bores in its lateral surface, the so-called suction holes, which can be subjected to negative pressure via suction air passages running axially in the interior of the roller. Due to the suction effect mediated by the negative pressure, the products to be transported can be held on the lateral surface of the roller.

A special case of using a vacuum roller relates to the takeover and transport of flat material blanks which are supplied to the roll in the form of a continuous material web and only in the state already in contact with the roll, for example by means of a knife roll rotating counter to the transport roll from the material web be separated. Usually, in this case, the feed rate of the material web to the roll is less than the web speed of the possibly rotating in the machine cycle roller, so that the flat material blanks abut against the material surface under the slip on the lateral surface of the roller until it is separated from the material web.

An example of such an application relates to the feeding of window material for gluing into envelope blanks in an envelope maker. Here, the window material, which is usually a transparent or semi-transparent material such as e.g. Pergamin acts in the form of a web of a roll to a vacuum roller (feed cylinder) out. The feed cylinder rotates in the machine cycle, i. with each complete rotation, a window blank to be glued is taken over and transported or transferred to the other processing stations for gluing and gluing.

The separation of the window blank from the material web takes place here by a knife roller which rotates counter to the supply cylinder.

Due to the feed in the form of a continuous material web, the window blank supplied between the feed cylinder and the knife roller with increasing rotation of the feed cylinder is in increasing length on the feed cylinder until it is severed by the knife roller. In the pre-separation period, the feed cylinder rotates under the blank, i. the window blank is slipped against the feed cylinder.

In order to ensure that the window blank abuts cleanly against the feed cylinder even before separation, the suction holes are already filled with suction air, even in the corresponding section of the lateral surface. Negative pressure applied, so that the blank is applied by the suction on the lateral surface.

In the application described above, various problems arise. Thus, due to the rotating through the blank feed cylinder continuously exposed with suction suction holes exposed, so that significant amounts of so-called. Missing air are sucked. This leads to a reduction the built-vacuum, so that to maintain a uniform and constant suction correspondingly higher pumping capacities of the negative pressure pumping system are needed.

This problem has been solved in the prior art as far as possible by the suction holes are connected by running in the lateral surface suction grooves. The suction grooves acting in a covering of the lateral surface with a window blank underneath the same as vacuum pockets convey the suction effect also in areas between the suction holes, so that the number of suction holes in the lateral surface could be reduced without having to dispense with an areal suction.

Furthermore, due to the abrasive concern of the window blank prior to separation from the material web on the lateral surface of the vacuum roll, in particular due to the suction grooves described above, there are grinding marks on the surface of the window blank contacting the roll. This is undesirable in particular for glassine or other transparent or semitransparent materials.

In order to avoid locally local grinding marks, therefore, a groove pattern was selected in the prior art, in which the grooves are arranged spirally on the lateral surface of the feed cylinder, so that results in a uniform matting of the surface of the window blanks by the grinding operations.

However, this solution is only conditionally acceptable since, due to the fact that the front section of the window blank in the transport direction is exposed to the grinding process for a significantly longer period than the rear section, the surface of the window blank has different levels of matting.

Of course, the above-described problems occur not only in the specific case of a letter feeding blank window feeding station but in every application of a vacuum roll for conveying a sheet blank as long as this transport, for whatever reason, takes place with a non-negligible slip between the roll surface and the flat material blank.

III. Presentation of the invention

a) Technical task

It is therefore an object of the present invention to provide a vacuum roller which avoids damaging the surface of the blanks in the event of slippage-laden transport of flat material blanks and at the same time enables the best possible intake air impingement with regard to incorrect air suction and suction on the products.

b) Solution of the task

This object is solved by the features of claims 1 and 9. Advantageous embodiments will be apparent from the dependent claims.

The vacuum roller according to the invention for transporting a flat material blank, has in its lateral surface on the usual suction holes, which can be acted upon by means extending within the roller axial Saugluftkanäle with suction. Furthermore, a plurality of suction-hole-connecting suction grooves are present in the lateral surface of the roller, which extend in a spiral over the lateral surface of the vacuum roller.

Suction-hole connecting means that the suction grooves each extend between at least two suction holes and thus connect them to one another. The suction grooves preferably have a straight-line structure on the lateral surface. However, it would also be conceivable for a suction groove to connect a plurality of suction holes to one another and in this sense to extend, for example, in a star shape between the corresponding suction holes. Curved Saugnutverläufe are possible in the present case. In a preferred embodiment of the invention, all suction holes of the roller are interconnected by suction grooves. If the suction holes in this case be distributed in alternating, mutually offset axial rows over the circumference of the lateral surface, then a diamond-like Saugnutenstruktur could result, with a suction hole can be arranged at each corner of a rhombus.

According to the invention, the suction grooves running helically on the lateral surface of the roll have a suction groove profile in which, viewed in a section perpendicular to the direction of the suction groove, the lateral suction groove walls in the transitional region form an angle of less than 20 ° with the surface of the roll. It is particularly preferred in this case if the lateral Saugnutwandungen form in the transition region to the lateral surface of the roller with this an angle less than 10 °. Ideally, the lateral Saugnutwandungen close in the transition region to the lateral surface of the roller substantially tangentially to this.

In this sense, the Saugnutwandungen in the transition region to the lateral surface can be rectilinear or have a suitable curvature.

In a particularly preferred embodiment of the invention, the two lateral Saugnutwandungen seen in a section perpendicular to the direction of the Saugnut approximately formed each of quarter circles, the transition area in the lateral surface of the roller substantially tangentially connect to this.

The Saugnutboden can in this case be substantially rectilinear. Preferably, in this case, the radii of the quarter circles are larger than the width of the Saugnutbodens. Optionally, this would also be conceivable that the suction grooves have no Saugnutboden as such, ie that the lateral Saugnutwandungen pass directly into each other in the bottom region of the groove. This would be Both a transition to form an angle, as well as a steady transition between the lateral Saugnutwandungen possible.

According to a further aspect of the invention, the suction grooves have a Saugnut- profile whose cross-sectional area perpendicular to the direction of less than 25%, in particular less than 20% of the cross-sectional area of a suction hole, between which extend the suction.

In this way, an increased suction effect can be achieved in the covered state of the groove, as a result of the cross-sectional conditions, a correspondingly better placement of the negative pressure in the areas within the Saugnuten.

Furthermore, the suction grooves may have a Saugnutprofil whose width seen in a section perpendicular to the direction of the Saugnut seen on the lateral surface of the roller substantially equal to the diameter of a suction hole or slightly larger than this.

By thus compared to the Saugnutenboden large width of the suction grooves on the lateral surface can be ensured that the blank to be held is applied over a relatively large area with a suction effect.

The inventive design of the lateral Saugnutwandungen in the transition region to the lateral surface of the roller ensures that the optionally slippery adhering to the lateral surface of the roller surface of the flat material blanks does not slide over sharp edges, thereby scratching the surface is minimized.

Also, due to the relatively shallow transition of the Saugnutwandungen to the lateral surface of the vacuum roller in these areas due to the flow conditions existing in the suction only a relatively limited negative pressure built up, so that only a reduced suction occurs in the critical for damaging the surface of the blanks transition areas. According to the invention, the suction grooves described above are produced by spirally guiding a shaping device along the lateral surface of the vacuum roll, wherein the shaping device, when guided in the circumferential direction perpendicular to the roll axis over the lateral surface, produces a Saugnutprofil, wherein in a section perpendicular seen to the direction of the Saugnut the lateral Saugnutwandungen in the transition region to the lateral surface of the roller with this form an angle of less than 20 °, in particular an angle less than 10 °.

Any shaping or non-chipping devices may be used as the shaping device used according to the invention, wherein preferably a milling cutter with a corresponding cross-sectional profile is used. It would also be conceivable to use a disk milling cutter with a corresponding profile. Other methods suitable for producing grooves, such as erosion, laser ablation, etc., can also be used for producing the inventive suction grooves according to the invention.

In the present case, a spiraling along a shaping device on the lateral surface of the vacuum roll is merely understood to mean that a relative spiral movement is carried out between the shaping device and the circumferential surface of the roll. In this sense, when producing the spirally arranged grooves, for example, the shaping device can be arranged stationary, while the roller is rotationally moved past the device in the axial direction. However, the roller may also be arranged in a stationary manner, while the shaping device is guided around the roller rotatingly past it in the axial direction. Also conceivable would be a combination of the two types of movement described above, ie that neither the shaping device, nor the lateral surface of the roller is stationary when generating the grooves, but they each perform rotational and / or translational movements. The respectively used variant of the helical Entlangführens a shaping device on the lateral surface of the vacuum roller is possibly also on the specific design of the forming device dependent.

It should also be clear that the shaping device for generating the grooves is optionally guided along the lateral surface so as to be immersed in the lateral surface, as is the case, for example, when using milling tools.

According to the invention, the shaping device used particularly preferably produces, when viewed in the circumferential direction perpendicular to the roll axis over the lateral surface, a suction groove profile in which the lateral suction groove walls in the transitional region are substantially tangential to the lateral surface in a section perpendicular to the direction of the suction groove connect them.

In a preferred embodiment of the invention, the shaping device, when it is guided in the circumferential direction perpendicular to the roll axis over the lateral surface, produces a Saugnutprofil, in which seen in a section perpendicular to the direction of the suction, the two lateral Saugnutwandun- gene are each formed approximately of quarter circles , which in the transition region to the lateral surface of the roller substantially tangentially connect to this.

The Saugnutboden between the lateral Saugnutwandungen here can rectilinear and substantially parallel to the lateral surface. In this case, the radii of the quarter circles are preferably larger than the width of the Saugnutbodens.

The shaping device can in this case, if it is guided in the circumferential direction perpendicular to the roll axis over the lateral surface, also produce a Saugnutprofil whose cross-sectional area seen in a section perpendicular to the direction of the Saugnut seen less than 25% of the cross-sectional area of a suction hole. The corresponding Saugnutprofil generated by the shaping device in a guide in the circumferential direction perpendicular to the roll axis may further have a width which is seen in a section perpendicular to the direction of the Saugnut seen on the lateral surface of the roll substantially equal to the diameter of a suction hole or slightly larger than this is.

According to another aspect of the present invention, the ratio of the cross-sectional area of an axial suction air passage to the sum of the cross-sectional areas of the suction holes communicating therewith is greater than 0.55. In this way, it can be ensured in the axial Saugluftkanälen due to the correspondingly high mass transport, that the suction holes and the suction grooves according to the invention associated with these can be acted upon with a sufficient negative pressure.

In a particularly preferred embodiment, the pitch angle of the spiral-shaped suction grooves between 20 ° and 50 °, in particular between 25 ° and 40 °, wherein the suction can be arranged in two sets of several parallel spirals and the two spiral sets with However, the same pitch angle extend in opposite directions over the lateral surface of the roller.

In order to ensure that, despite a small number of suction holes in the lateral surface, a surface loading of the products to be transported takes place, in a preferred embodiment of the vacuum roller according to the invention in that region of the circumferential surface of the roller, the suction grooves, the ratio between that of the Saugnuten and suction holes occupied proportion of the lateral surface to the total surface area between 25 and 40%. c) embodiments

A preferred embodiment of the invention will be described below with reference to the figures.

Show it:

Fig. 1 is an axial side view of a preferred embodiment of a vacuum roller according to the invention;

FIG. 2a shows a cross section of the vacuum roller shown in FIG. 1; FIG.

Fig. 2b is an enlarged detail of Fig. 2a;

3a shows an enlarged detail of an axial section through a vacuum roller with a suction hole, through which a suction groove generated in the circumferential direction perpendicular to the roll axis on the lateral surface of the roller runs; and

3b shows a cross-section with respect. The course direction of a circumferential direction perpendicular to the roll axis on the outer surface of the roller suction groove.

FIG. 1 shows a side view of a vacuum roller 1 according to the invention in the form of a window section cylinder of an envelope production machine. The roller 1 in this case has over its lateral surface 2 in a regular arrangement distributed suction holes 3. In particular, the suction holes 3 are arranged on the lateral surface 2 in two alternating, mutually offset axial rows.

As shown schematically in FIG. 1, the suction holes 3 on the lateral surface 2 of the roller 1 are connected to one another by suction grooves 4. In this case, the suction grooves 4 extend in two sets each of a plurality of parallel arranged Helical lines over the lateral surface 2. The two helix sets have the same pitch angle Θ with respect to the roller 1 of about 33 °, but extend in opposite directions over the lateral surface. 2

The suction grooves 4 thus form on the lateral surface 2 of the roller 1 a diamond-like pattern, wherein at each intersection of the grooves 4, a suction hole 3 is arranged.

FIG. 2 shows a section through the roll 1 shown in FIG. 1, wherein FIG. 2 b shows a detailed detail from FIG. 2 a. For reasons of simplification, the suction grooves 4 extending through the suction holes 3 are not shown in FIGS. 2a and 2b.

As shown in Figure 2a, the roller 1 in the illustrated embodiment in its interior axially extending Saugluftkanäle 5, which are distributed in the present case at a uniform angular distance of 10 ° below the lateral surface 2 lying over the circumference of the roller 1. Consequently, in the example shown, the roller 1 has a total of 36 axial suction air ducts 5.

Each of the suction air ducts 5 extends axially substantially over the entire length L of the roller 1 and can be acted upon via one or both end faces 6 of the roller 1 with suction air. A row of suction holes 3 is in each case connected to the axial suction air ducts 5, which are supplied with suction air via the respective suction air duct 5 in order to hold the window section to be transported on the lateral surface 2 of the roll 1.

In the illustrated embodiment, the diameter DA of the axial Saugluftkanäle 5, the diameter DS of the suction holes 3 and the number of Saugluftkanal 5 associated Sauglöcher 3 are selected such that the ratio of the cross-sectional area of an axial Saugluftkanals 5 to the sum of the cross-sectional areas with this communicating suction holes 3 is greater than 0.55. In particular, this ratio is presently in the range of 0.55 to 0.70. Such a ratio leads to a particularly advantageous suction air admission of the suction holes 3 due to the resulting mass flow distribution.

Due to the spiral course of the suction grooves 4 on the lateral surface 2 of the roller 1, the actual existing profile of the suction groove 4 in a section transverse to the direction of the suction groove 4 can not be readily graphically represented. Also, an exact description of the present on the lateral surface 2 geometric conditions of a spiral-extending Saugnut 4 words is insufficiently possible.

For these reasons, a simplified case is shown for the sake of better understanding and clarity in FIGS. 3a and 3b, which can be regarded as a good approximation to the actually existing conditions. More specifically, Figures 3a and 3b illustrate the case where the forming apparatus is not spirally guided along the lateral surface 2 of the roller 1, as is necessary to produce the suction grooves 4 shown in Figure 1, but rather perpendicular to the axis A of the roller 1 is guided in the circumferential direction over the lateral surface 2 of the roller 1.

This approximation corresponds to the case in which the diameter DW of the roller 1 is sufficiently large with respect to the width NB of the suction grooves 4 on the lateral surface 2 of the roller 1, so that the curvature of the lateral surface 2 influencing the geometry of a spiral course of the suction grooves 4 is negligible. Since, in the example shown in FIG. 1, this ratio is in the range of 1 to 2%, the approximation case shown in FIGS. 3a and 3b should describe the actually existing conditions sufficiently well.

Accordingly, Figure 3a shows an enlarged detail of an axial section through the roller 1 in the region of the lateral surface 2. The illustrated suction hole 3 communicates with one of the axial Saugluftkanäle 5 in connection.

Through the suction hole 3 extends a suction groove 4, which, as previously mentioned, in Figure 3a is not spirally under the pitch angle Θ, but in Umfangsrich- tion perpendicular to the axis A of the roller 1 on the lateral surface 2 extends. Consequently, the profile of the suction groove 4 can be seen in a section perpendicular to the direction of the suction groove 4 in Figure 3a, which is shown in Figure 3b again in more detail.

While the suction groove 4 in FIG. 3 a is shown in a crossing region with a suction hole 3, FIG. 3 b shows an enlarged section through the suction groove 4 perpendicular to the direction of the suction groove 4 in a region of the lateral surface 2 of the roll 1 which is at a distance from the suction holes 3.

As shown in Figure 3b, the profile of the suction groove 4 is seen in cross-section to the direction of symmetry formed and is composed of several sections together. The centrally arranged Saugnutenboden 7 in this case extends substantially rectilinearly and parallel to the lateral surface 2 of the roller first

At the Saugnutenboden 7 close in the illustrated embodiment of the invention on both sides of the side walls 8 of the suction groove 4 at. In the present case, the side walls 8 are formed by essentially arcuate sections 9 with a radius R and by sections 10 which are substantially rectilinear and adjoin the arcuate sections 9, the sections 10 in the present case at an angle Ω of approximately 10 ° to the Connect shell 2.

In the present example, the circular arc-like sections 9 do not form a complete quadrant circle but cover approximately an angular range of 75 °. It is also conceivable that the circular arc-like sections 9 of the side walls 8 of the suction groove 4 extend substantially over a complete quadrant, wherein the lateral surface 2 would then ideally be tangential to the sections 9.

In the illustrated embodiment, the radius R of the quarter-circle-like portions 9 is made larger than the width B of the Saugnutenbodens 7 to a favorable negative pressure distribution in the Saugnut 4 and thus to achieve suction when exposed to suction.

The total width NB of the suction groove 4 is substantially equal to or slightly larger than the diameter DS of the suction holes 3, so that a sufficiently large area covered with suction can be ensured.

Due to the presently selected geometric dimensions of the suction groove 4, a cross-sectional area of the suction groove 4 results perpendicular to the direction of the suction groove 4, which is less than 25% of the cross-sectional area of the suction holes 3.

Overall, in the illustrated example, the width NB of the Saugnuten 4, the diameter DS of the suction holes 3 and the number and arrangement of the suction holes 3 on the lateral surface 2 of the roller 1 selected such that in that region of the lateral surface 2, the suction grooves 4 in that the ratio between the proportion of the lateral surface 2 occupied by the suction grooves 4 and suction holes 3 to the total lateral surface is approximately 35%.

In the illustrated embodiment of the vacuum roll 1 according to the invention, a milling cutter has been used as the shaping device, the cross-sectional profile of which substantially corresponds to the profile of the suction groove 4 shown in FIG. 3b. Here, in the present embodiment, the roller 1 was guided axially about its axis A axially on the stationary arranged end mill, ie the end mill was spirally guided in this sense at the pitch angle Θ on the lateral surface 2 of the roller 1 along the two opposing sets to obtain a plurality of parallel Saugnuten 4 with the desired profile shape according to the invention. LIST OF REFERENCE NUMBERS

1 vacuum roller 2 lateral surface of 1

3 suction holes

4 suction grooves

5 suction air ducts

6 faces of 1 7 Saugnutenboden

8 side walls of 4

9 quadrant section

10 straight sections

A axis of 1

DW diameter of 1

L axial length of 1

Θ pitch angle of the spiral lines

DA diameter of 5 DS diameter of 3

R radius of 8

Ω Angle of Saugnutwandung in the transition to 2

NB width of 4

B width of 7

Claims

1. Vacuum roller (1) for transporting a flat material blank, wherein the lateral surface (2) of the vacuum roller (1) suction holes (3) by means of within the

Roller (1) extending axial Saugluftkanäle (5) can be acted upon with suction, and a plurality of Sauglochverbindende Saugnuten (4) which extend helically over the lateral surface (2) of the vacuum roller (1), I d ne u ke nnze net in that the suction grooves (4) are produced by spirally guiding a shaping device along the lateral surface (2) of the vacuum roll (1), the shaping device, when traveling in the circumferential direction perpendicular to the roll axis (A), over the lateral surface ( 2), a suction groove profile is produced in which the lateral Saugnutwandungen (8) in the transition region to the lateral surface (2) of the roller (1) seen in a section perpendicular to the direction of the Saugnut (4) with this one angle (Ω) smaller 20 ° form.

2. vacuum roll (1) according to claim 1, d ad u rch ge ke n nn nze me n et, as the ss forming device when it is guided in the circumferential direction perpendicular to the roll axis (A) on the lateral surface (2), generates a Saugnutprofil in which the lateral Saugnutwandungen (8) in the transition region to the lateral surface (2) of the roller (1) with this form an angle (Ω) of less than 10 ° in a section perpendicular to the direction of the suction groove (4).

3. Vacuum roll (1) according to one of the preceding claims, characterized in that the shaping device, when it is guided in the circumferential direction perpendicular to the roll axis (A) on the lateral surface (2), a Saugnutprofil produced, in which the lateral Saugnutwandungen (8) in the transition region to the lateral surface (2) of the roller (1) in a section perpendicular to the direction of the suction groove (4) substantially tangentially to the lateral surface (2) connect.

4. vacuum roll (1) according to claim 3, characterized in that the shaping device when it is guided in the circumferential direction perpendicular to the roll axis (A) on the lateral surface (2), generates a Saugnutprofil, wherein in a section perpendicular to the direction of the Suction groove (4) seen the lateral Saugnutwandungen (8) approximately of quarter circles (9) are formed, which in the transition region to the lateral surface (2) of the roller (1) substantially tangentially to the lateral surface (2).

5. Vacuum roller (1) one of the preceding claims, characterized in that the Saugnutboden (7) between the lateral Saugnutwandungen (8) is substantially rectilinear and parallel to the lateral surface (2) of the roller (1).

6. Vacuum roller (1) according to claim 4 in conjunction with claim 5, characterized in that the radii (R) of the quarter circles (9) are greater than the width (B) of the Saugnutbodens (7).

7. Vacuum roller (1) according to one of the preceding claims, characterized in that the shaping device when it is guided in the circumferential direction perpendicular to the roll axis (A) over the lateral surface (2), generates a Saugnutprofil whose cross-sectional area in a section perpendicular to Viewing direction of the suction groove (4) seen less than 25% of the cross-sectional area of a suction hole (3).

8. Vacuum roll (1) according to one of the preceding claims, characterized in that the shaping device, when it is guided in the circumferential direction perpendicular to the roll axis (A) over the lateral surface (2), generates a Saugnutprofil whose- width (NB) on the lateral surface (2) of the roller (1) in a section perpendicular to the direction of the suction groove (4) substantially corresponds to the diameter (DS) of the suction holes (3).

9. Vacuum roller (1) for transporting a flat material blank, wherein the lateral surface (2) of the vacuum roller (1) suction holes (3) by means of within the

Roller (1) extending axial Saugluftkanäle (5) can be acted upon with suction, and a plurality of suction hole connecting Saugnuten (4) which extend helically over the lateral surface (2) of the vacuum roller (1), characterized in that the suction grooves (4) a Suction groove profile, in which the lateral Saugnutwandungen (8) in the transition region to the lateral surface (2) of the roller (1) seen in a section perpendicular to the direction of the Saugnut (4) form with this an angle (Ω) less than 20 °.

10. Vacuum roller (1) according to claim 9, characterized in that the suction grooves (4) have a Saugnutprofil, in which seen in a section perpendicular to the direction of the Saugnut (4), the lateral Saugnutwandungen (8) in the transition region to the lateral surface (2 ) of the roller (1) with this an angle (Ω) less than 10 °.

11. Vacuum roller (1) according to claim 9 or 10, characterized in that the suction grooves (4) have a Saugnutprofil, in which seen in a section perpendicular to the direction of the suction groove (4), the lateral Saugnutwandungen (8) in the transition region connect the lateral surface (2) of the roller (1) substantially tangentially to the lateral surface (2).

12. Vacuum roller (1) according to claim 11, characterized in that the suction grooves (4) have a Saugnutprofil, in which in a section perpendicular to the direction of the Saugnut (4) seen the side Saugnutwan- fertilize (8) approximately of quarter circles (9 ) are formed, which in the transition region to the lateral surface (2) of the roller (1) substantially tangentially to the lateral surface (2)

13. Vacuum roller (1) according to one of claims 9 to 12, characterized in that the Saugnutboden (7) between the lateral Saugnutwandungen (8) is substantially rectilinear.

14. Vacuum roller (1) according to claim 12 in conjunction with claim 13, characterized in that the radii (R) of the quarter circles (9) are greater than the width (B) of the Saugnutbodens (7).

15 vacuum roller (1) according to any one of the preceding claims 9 - 14, characterized in that the suction grooves (4) have a Saugnutprofil whose cross-sectional area perpendicular to the extending direction of the suction (4) is less than 25% of the cross-sectional area of a suction hole (3) ,

16. Vacuum roller (1) according to any one of the preceding claims 9-15, characterized in that the suction grooves (4) have a Saugnutprofil whose width (NB) on the lateral surface (2) of the roller (1) in a section perpendicular to the direction the suction groove (4) substantially corresponds to the diameter (DS) of the suction holes (3).

17. Vacuum roller (1) according to one of the preceding claims, characterized in that the ratio of the cross-sectional area of an axial suction air duct (5) to the sum of the cross-sectional areas of the associated with this suction holes (3) is greater than 0.55.

18. Vacuum roller (1) according to one of the preceding claims, characterized in that it is a finger milling cutter in the shaping device.

19. Vacuum roller (1) according to one of the preceding claims, characterized in that the pitch angle (Θ) of the spirally extending suction grooves (4) is between 20 ° and 50 °.

20. Vacuum roll (1) according to any one of the preceding claims, characterized in that the suction grooves (4) are arranged in two sets of a plurality of parallel spirals, wherein the two sets of spirals with the same pitch angle (Θ) but opposite to the Cover surface (2) of the roller (1) extend.

21. Vacuum roller (1) according to one of the preceding claims, characterized in that in that region of the lateral surface (2) of the roller (1), the suction grooves (4), the ratio between that of the Saugnuten (4) and suction holes ( 3) assumed proportion of the lateral surface (2) to the total surface area between 25% and 40%.