CN112703096B

CN112703096B - Transverse cutting device and method for stabilizing cut edges during extrusion cutting

Info

Publication number: CN112703096B
Application number: CN201980047023.9A
Authority: CN
Inventors: M·博格; T·格特克; F·赫佩尔
Original assignee: BW Papersystems Hamburg GmbH
Current assignee: BW Papersystems Hamburg GmbH
Priority date: 2018-07-13
Filing date: 2019-07-02
Publication date: 2022-11-01
Anticipated expiration: 2039-07-02
Also published as: JP2021531985A; WO2020011599A1; CN112703096A; JP7125536B2; EP3645226A1; ES2908857T3; EP3645226B1; DE102018122005A1

Abstract

The invention relates to a transverse cutting device for cutting or transversely separating a running material web into sheets and to a method for stabilizing the cut edges during a pinch cut in a transverse cutting device. The transverse cutting device is provided with: a knife drum which can rotate around a rotation axis extending transversely to the material web and the conveying direction thereof is used as a rotatable cutting device, and the knife drum is provided with at least one knife extending along the axial direction of the knife drum and encircled by the knife drum; a corresponding anvil drum which can be rotated about a rotation axis extending transversely to the web and its transport direction, which anvil drum is arranged vertically below the knife drum, and which performs a press cut along the cutting line when the knives of the knife drum are in contact with the anvil drum, the knife drum having at least one presser in its circumference in the transport direction of the web before the knives. According to the invention, the presser has a distance and/or a radial extension from the knife, so that the web comes into contact with the presser during the press-cutting and is arched in the direction of the anvil drum by the presser.

Description

Transverse cutting device and method for stabilizing cut edges during extrusion cutting

Technical Field

The invention relates to a transverse cutting device, in particular for cutting or transversely separating an advancing material web, preferably made of paper, cardboard, plastic and/or metal, into sheets, having: a knife drum which can be rotated about a rotational axis extending transversely to the material web and its transport direction, as a rotatable cutting device, wherein the knife drum has at least one knife extending in the axial direction of the knife drum and surrounded by the knife drum; a corresponding anvil drum which is rotatable about a rotation axis extending transversely to the web and its transport direction, wherein the anvil drum is preferably arranged vertically below the knife drum, wherein a press cut along the cutting line is performed when the knives of the knife drum are in contact with the anvil drum, wherein the knife drum has at least one presser in front of the knives in the transport direction of the web on its circumference. The invention also relates to a method for stabilizing the cut edge during the pinch cutting in a transverse cutting device.

Background

Transverse cutting devices consisting of a knife drum and a corresponding anvil drum performing a press cut are known from the prior art. This transversely cuts the advancing web into sheets so that the knives of the knife drum come into contact with the anvil drum. To ensure a perfect cut, the knife can preferably slide through the anvil substantially without play. Guide plates are usually arranged behind the transverse cutters in the transport direction of the sheets, which guide plates serve for accommodating and further transporting the sheets. The guide plate is here usually arranged behind the anvil drum with a small gap. The gap left between the guide plate and the anvil drum is limited by the structure, which cannot be avoided because the touching contact between the anvil drum and the guide plate may cause damage to the guide plate and/or the anvil drum.

The cutting edges of the web or of the cut sheet often stick to the surface of the anvil drum after cutting and run with the anvil drum in such a way that a transfer to the guide plate may be hindered or significantly disturbed. The leading edge of the web may, for example, enter the gap between the anvil drum and the guide plate. The respective sheet is then not fed to further processing and may therefore interfere with the running process. However, it may also happen that the leading cutting edge of the web adheres to the knives of the knife drum and runs with the knife drum. This undesired behavior of the web or sheet may also lead to malfunctions which may lead to a stoppage of the transverse cutting device and to a manual correction of the position of the sheet.

Disclosure of Invention

The object of the invention is to provide a transverse cutting machine in which the leading edge of the foil is effectively prevented from running with the knife drum and/or the anvil drum. At the same time, the cutting quality should be improved. Furthermore, a method should also be provided which overcomes the above-mentioned disadvantages and fulfills the task described in this paragraph.

The aforementioned object is achieved by a transverse cutting device and by a method.

The transverse cutting device is provided with: a knife drum which can be rotated about a rotational axis extending transversely to the material web and its transport direction, wherein the knife drum has at least one knife extending in the axial direction of the knife drum and rotating with the knife drum; a corresponding anvil drum which is rotatable about a rotation axis extending transversely to the web and its transport direction, wherein a press cut along the cutting line is carried out when the knives of the knife drum are in contact with the anvil drum, wherein the knife drum has at least one presser in its circumferential direction in front of the knives in the transport direction of the web, wherein the presser has a spacing and/or a radial extension from the knives, so that the web is in contact with the presser at the time of the press cut and is arched by the presser in the direction of the anvil drum, wherein the anvil drum has at least one lifter in front of the cutting line in the transport direction of the web to stabilize the web during the cutting process, wherein according to the invention the lifter is arranged at least substantially in front of the presser in the transport direction of the web in the movement condition of the cooperating knife drum and anvil drum, wherein the lifter is spaced further from the cutting line in the transport direction of the web than the presser in the cutting process, wherein the spacing between the lifter and the presser is at least 2 mm.

In the method, the pinch cut is carried out with the above-described transverse cutting device, according to the invention, the web is brought into contact with at least one presser of the knife drum of the transverse cutting device in the region of the newly formed front edge during the pinch cut, and is arched by the presser in the direction of the anvil drum of the transverse cutting device.

The invention also relates to other advantageous embodiments.

Tests carried out within the scope of the invention have shown that the cutting quality of the transverse cutting device strongly depends on the position of the web relative to the knife and relative to the anvil drum. Thus, according to the invention, the presser of the transverse cutting device has a distance to the knives and/or a length in the direction of the anvil drum or a radial extension (with reference to the position of the presser at the time of the press cut), so that the web is in contact with the presser at the time of the press cut and is arched by the presser in the direction of the anvil drum. The compactors are arranged in the transport direction of the web before the knives on the circumference of the knife drum. The material web is fed to a transverse cutting device via a guide plate and cut into sheets. The web is pressed down towards the anvil drum directly before and during cutting. After the cut is performed, the presser also presses the front area of the web downwards in the direction of the anvil drum. On the one hand, this prevents the leading edge from running with the drum. On the other hand, the web is arched in the direction of the anvil drum and is thus stabilized in its position during cutting, thereby producing a significantly improved cutting result.

The invention is therefore based on the idea that the web is temporarily arched before and during the cutting and is thereby stabilized, in particular during the cutting. The cutting quality is improved due to the higher stability of the web. Furthermore, the web is effectively prevented from running with the knife drum by the presser.

The cutter drum may have a single cutter, which preferably extends substantially the entire length of the cutter drum. Such a drum performs the cutting at each complete rotation. The drum may alternatively have a plurality of cutters, which extend over the entire length of the drum. The cutter drum performs the cutting of the number corresponding to the number of the cutters every time the cutter drum rotates. In the last-mentioned case, the respective transverse cutting device also has a plurality of cutting lines and therefore in any case also a plurality of compactors. It is also possible to divide the knives extending over the entire length of the drum into a plurality of knife segments or knife segments. The cutter segments can then be exchanged independently of one another and/or adapted to the width of the web.

The web is advantageously pressed against the anvil drum by the presser during the press cutting and already directly abuts against the anvil drum before the press cutting. The presser acts towards one, preferably upper, flat side of the web and presses the web with the other flat side against the anvil drum. The web is thus clamped between the presser and the anvil drum and guided with the movement of the two drums during cutting. The resulting camber in the web and the clamping of the sheet between the anvil drum and the presser cumulatively improves the stability of the web at cutting. In this way, a reproducible cut, in particular a reproducible and stable position of the web during the cut, is produced, whereby the quality of the cut is improved.

In an advantageous embodiment of the invention, the anvil drum has at least one lifter in the transport direction of the web before the cutting line for stabilizing the web during the cutting process. The material web is fed to the transverse cutting device via a guide plate, at least partially rests on a lifter and is pressed by a presser S in the transport direction preferably in the direction of the anvil drum. The web is preferably placed on the anvil drum during cutting in the region of the presser and the cutting line. The S-shaped curvature greatly improves the stabilization of the material web, thereby positively influencing the quality of the cut and the reproducibility of the cut. This broadly confirms the tests performed within the scope of the present invention.

Furthermore, the lifter has the function of preventing the leading edge or the front area of the web from running with the anvil drum. If the two drums continue to rotate after cutting the web, the distance between the presser and the anvil drum is increased such that the presser no longer presses the web against and/or in the direction of the anvil drum. Due to the now lack of resistance, the web is lifted radially by the lifters and then no longer rests on the anvil drum in the region of the leading edge. The curvature of the web is reduced during this process until the web is no longer curved or is only slightly curved. The cutting edge itself is then placed neither on the lifter nor on the anvil drum. In this way, the front edge region of the web is effectively prevented from running with the anvil drum.

The lifter is advantageously arranged at least substantially before the presser in the transport direction of the web in the movement condition of the cooperating knife and anvil drums. The movement conditions of the knife drum and the anvil drum which cooperate with one another describe the coordinated rotary movement of the knife drum and the anvil drum and the cooperation of the lifter and the presser which occurs here. In this case, the lifter and the presser preferably act simultaneously on different flat sides of the web during the press cutting. Here, the lifter is preferably spaced apart from the presser in the circumferential direction of the drum. This means that the lifter is spaced further from the cutting line in the transport direction of the web or the circumferential direction of the drum in the cutting than the presser. When the two drums rotate opposite to each other, the lifter and the presser come into contact with the web such that this web rests at least partially on the presser and is arched by the cooperation of the presser and the lifter. In the region of the cutting line, the web is preferably placed on an anvil drum during cutting. By selecting the distance in the circumferential direction between the lifter and the presser, the arching of the web can be influenced during cutting. The spacing between the lifter and the presser is preferably at least 1 mm, more preferably at least 2 mm.

In a preferred embodiment, a plurality of lifters spaced apart from one another and/or compactors spaced apart from one another are arranged transversely to the transport direction of the webs and the webs. The lifters spaced apart from each other divide a lifting area and the pressers spaced apart from each other divide a pressing area. A uniform arching of the web over the entire width of the web can be produced by a plurality of lifters and/or compactors spaced apart from one another. This contributes in particular to a higher stabilization of the web in the cut and to an improvement in the cut quality. The lifter and the presser can advantageously be arranged offset from one another in the transport direction of the material web. Thus, arching can occur in a manner that protects the material.

The knife drum preferably has at least one presser behind the knife in the transport direction of the web on its circumference. By arranging an additional presser after the knife in the transport direction, the web is pressed by the presser before and after the knife in the cutting direction towards the anvil drum. The web is thus stabilized on both sides of the knife. In this way the cutting quality can be further improved.

The presser and the lifter may be arranged in engagement with each other in the pressing cut at least in the edge region. The compactor and the lifter can then be spaced apart from one another transversely to the transport direction and overlap in the edge regions facing one another in the transport direction. If the presser and the lifter overlap or engage at least temporarily and in the edge region during the cutting process, an advantageous curvature or arching of the web in the transport direction is achieved on the one hand and an arching of the web transverse to the transport direction is also achieved on the other hand. If several lifters and compactors spaced apart from one another are provided transversely to the web, a wave-shaped curvature of the web can be produced transversely to the transport direction. The curvatures of the webs occurring in the transport direction and transversely thereto overlap and form a complex, three-dimensional curvature in the webs. The aforementioned curvature allows the web to be fastened in its position in a reproducible manner in a particularly stable manner and produces a particularly advantageous cut quality.

The lifter and/or the compressor are further preferably made of a resilient material, for example a foam material, a rubber material or an elastomer material. In this way, the passage of the material web can be improved. Due to the elastic properties of the lifter and of the presser, a curvature is produced in the web in a material-protecting manner. It is thus possible in an effective manner to prevent, damage or otherwise negatively affect the surface of the web. The lifter and the compactor can, based on their elastic material, balance the web variations, for example when using thicker webs, without damaging the web or negatively affecting the process. The lifter may also be of a stiff material. The lifter may, for example, be milled into the anvil, wherein the lifter in this case is of the same material as the anvil. The lifter and the presser are therefore suitable for the various possible web properties to be treated.

The lifter and the presser may each be designed as a separate component and be arranged and fastened interchangeably on the knife drum or the anvil drum. The lifter and the presser can be connected to the anvil or knife drum in a simple manner by means of a screw connection or clamping and can therefore be easily replaced and/or exchanged. The lifter and the presser can thus be selected to match the respective requirements of the process or the web and then mounted on the respective drum. The lifters and compactors could alternatively be irreplaceably connected to the drum. The lifter and the presser may be, for example, integrally connected to the respective drum or non-detachably connected, for example adhesively bonded, to this drum. It is not excluded to configure the lifter and/or the compactor height adjustable. Height-adjustable means in this context that the lifter and/or the compressor may be configured to be movable and/or adjustable in the radial direction. In this way, the lifter and/or the compressor can be used in different application situations and aligned radially as required. The radial adjustment can be done, for example, hydraulically or mechanically, for example, by adjusting screws. Corresponding devices and methods for radially adjusting elements are known to the person skilled in the art.

Preferably, a plurality of grippers is provided transversely to the transport direction, wherein the sum of the total extension of the grippers in the longitudinal direction of the knife drum, that is to say the sum of the individual lengths, may be at least 5%, preferably at least 10%, preferably 15% to 45%, of the length of the knife drum. The compactors are preferably evenly spaced apart from each other in the longitudinal direction of the drum. A uniform curvature in the web is produced over the width of the web by a corresponding arrangement of the holddowns. The material web is also uniformly secured during the cutting, so that the quality of the cut along the cut is always of high quality.

Advantageously, a plurality of lifters is provided, wherein the added extension of the lifters in the longitudinal direction of the anvil drum, that is to say the sum of the individual lengths, corresponds to at least 2%, preferably at least 5%, preferably at least 10%, preferably 15% to 45% of the length of the anvil drum. The lifters are preferably evenly spaced from each other in the longitudinal direction of the anvil drum. The alignment of the lifters results in an even arching of the web and thus in an even fastening of the web in the cut. At the same time, it is ensured that the front region of the web is lifted in the radial direction after cutting and is prevented from running with the anvil drum.

If a plurality of lifters and a plurality of pressers are provided, the lifters and anvil drum alternate in a direction transverse to the web, so that there is an alternating arrangement of lifters and pressers.

In a further advantageous embodiment of the invention, a guide plate for receiving the front cutting edge region of the web or sheet is arranged behind the anvil drum in the transport direction of the web. The radial spacing between the guide plate and the anvil drum and/or the spacing in the circumferential direction of the drum is of decisive significance here. If the guide plate is too far from the anvil drum, there is a risk that the foil will enter the gap between the guide plate and the anvil drum. In this case, the process must be stopped and the sheet manually transferred to the guide plate. If the spacing between the guide plate and the anvil drum is too small, the guide plate and the rotating anvil drum may come into contact, which may result in damage to the guide plate and the anvil drum. This may in particular negatively affect the quality of the cuts performed. The spacing is particularly preferably in the range from 0.1 to 2 mm, but can also be greater or smaller. In principle, the transport of the foil can also be continued without guide plates.

Advantageously, the spacing of the guide plate from the anvil drum is adjustable, for example by means of hydraulic, pneumatic and/or mechanical adjustment means. In this way, the distance can be adjusted to the requirements of the process and to the material web to be treated.

The guide plate can advantageously have a blunt or sharp edge with which the guide plate is arranged relative to the anvil drum. The sharp edge of the guide plate can be advantageous, so that the spacing between the guide plate and the anvil drum can be kept particularly small, so that the leading edge of the lamella can be prevented very effectively from penetrating into the region between the anvil drum and the guide plate. By targeted orientation of the spacing between the guide plate and the anvil drum, fault situations can be effectively avoided. The orientation of the guide plate relative to the anvil drum can also be varied and thus matched to the implementation of the cutting process.

The guide plate preferably has at least one recess or groove on the side facing the anvil drum, through which the elevator is guided during rotation of the anvil drum. The leading region of the web is placed on the lifter after cutting and is radially spaced from the anvil drum. The lifter is responsible for lifting or handing over the front area of the web onto the guide plate. When the anvil drum is rotated further, the lifter is guided through the cut-out or slot of the guide plate, so that when the lifter is completely guided through the cut-out or slot of the guide plate, the front region of the web rests at the latest on the guide plate. If the anvil drum has a plurality of lifters, it is preferred that each lifter is assigned a recess or groove through which the lifter is guided during rotation of the anvil drum. In this way, it is ensured that the front region of the web is lifted or transferred uniformly over its entire width onto the guide plate.

In the method according to the invention, the material web is contacted with at least one presser of the knife drum of the transverse cutting device in the region of the leading edge reformed during the pressing cut during the cutting and is arched by the presser in the direction of the anvil drum of the transverse cutting device. Particularly preferred is an embodiment in which the web is in contact with at least one lifter of the anvil drum during the pinch cutting in the region before the leading edge reformed during cutting and is lifted by the lifter in the direction of the knife drum, wherein it is further preferred that the web is substantially S-shaped arched in the region between the lifter and the presser.

According to the invention, the web is curved in the region of the leading edge reformed during the cut in the cross-cut by at least one lifter and at least one spaced-apart presser for stabilization during the cut. The lifter can lift the region of the front edge of the web from the anvil drum after the cross cut, wherein the front edge of the web can be handed over to a guide plate provided with at least one recess or groove in order to prevent the web from running with the knife drum. The web is thus stabilized before and during cutting. The method thus results in better reproducibility of the cutting process and better quality of the cut edges. At the same time, a transfer of the front region of the material web to a guide plate arranged downstream of the transverse cutting device is achieved in a reliable manner.

The embodiments of the invention described above can be combined with one another as required, even if this is not explicitly mentioned in detail. The present disclosure is not limited to the combination of inventive features predetermined by the selected paragraph format.

Further features of the invention emerge from the following description of preferred embodiments of the invention with the aid of the drawing and from the drawing itself. All described and/or illustrated features here form the subject matter of the present invention, either individually or in any combination.

Drawings

In the drawings:

fig. 1 shows a schematic representation of a transverse cutting device according to the invention in cross section;

fig. 2 shows a perspective view of the cutting region of the transverse cutting device of fig. 1 in a schematic illustration;

fig. 3 is a schematic cross-sectional view of the transverse cutting device shown in fig. 1 after cutting has been performed; and is

Fig. 4 shows a perspective view of the anvil drum and the guide plate for guiding out the material of the transverse cutting device according to the invention from fig. 1 in a schematic illustration.

Detailed Description

Fig. 1 shows a cross cutting device 1 for cutting or cross-cutting an advancing web 2 into sheets 3. The material web 2 is fed into the cross cutting device 1 by means of an infeed guide plate 4. From the input guide plate 4, the material web 2 is guided into a cutting region between the knife drum 5 and a corresponding anvil drum 6 arranged below the knife drum 5. The web 2 is cut into sheets 3 in a cutting zone. Subsequently, the web 2 or the sheet 3 is transported away from the cross cutting device 1 by a guide plate 7 which is guided out and fed to a further processing operation.

For cutting the web 2, the knife drum 5 has at least one knife 8, which preferably extends over the entire length of the knife drum 5. A presser 9 is arranged on the knife drum 5 in front of the knives 8 in the transport direction 10. The pressure means 9 can preferably be arranged directly in front of the tool 8 or also at a distance from the tool 8.

When the cutting is performed, the knife 8 and the anvil drum 6 are in contact with each other along the cutting line. A lifter 11 is arranged on the anvil drum 6. The lifter 11 is arranged in the transport direction 10 of the web 2 before the cutting line and spaced apart from this cutting line. As shown in fig. 1, a lifter 11 is arranged before the presser 9 in the transport direction 10 of the web 2 and spaced apart from the presser 9, with reference to the cutting positions of the

drums

5, 6 shown in fig. 1. However, it is also possible for the presser 9 and the lifter 11 to partially overlap in the transport direction 10 in the cutting position of the

drums

5, 6.

The web 2 is pressed by the presser 9 in the direction of the anvil drum 5 before and during cutting. During or after the cutting process, web 2 rests at least partially on lifter 11. The presser 9 presses onto the upper flat side of the web 2 and presses the web 2 with the opposite flat side in the direction of the anvil drum 6, wherein the web 2 preferably therefore abuts against the anvil drum 6. The web 2 may also be clamped or fixedly held between the presser 9 and the anvil drum 6. In the region of the cutting line, the web 2 is in any case placed on an anvil drum 6. In the transport direction 10 upstream of the knife, the web 2 is preferably curved in a substantially S-shaped manner due to the cooperation of the presser 9 and the lifter 11. In this way, web 2 is secured in a stable position during cutting, thereby positively influencing the cutting quality.

Fig. 2 shows that a plurality of compactors 9 and lifters 11 are arranged one behind the other transversely to the transport direction 10 of the material web 2 or in the longitudinal direction of the

drums

5, 6. Fig. 2 shows the knife drum 5 and the anvil drum 6 in a cutting state. The knife drum 5 has a plurality of pressers 9 which are spaced apart from one another uniformly. The anvil drum 6 likewise has a plurality of lifters 11, which are also evenly spaced apart from each other. The grippers 9 and the lifters 11 are arranged alternately transversely to the transport direction 10. The spacing between two adjacent compactors 9 preferably corresponds at least to the width of the lifter 11. The presser 9 and the lifter 11 may have a spacing of at least 1 mm from each other transversely to the transport direction 10, for example.

In the arrangement shown in fig. 1 and 2, the presser 9 and the lifter 11 do not overlap with reference to the position in the cutting along the transport direction 10 and may, for example, have a spacing of at least 1 mm from each other. It is also possible, however, for the lifter 11 and the presser 9 to engage with one another with reference to the position in the cut. The web 2 is thus deformed in the region of the lifter 11 and the presser 9 in the transport direction 10 and transversely thereto. In this way, a complex and particularly stable three-dimensional curvature of web 2 during cutting can be achieved, thereby greatly improving the cutting quality.

As shown in fig. 1 and 2, the presser 9 and the lifter 11 are spaced apart from each other in the circumferential direction of the

drums

5, 6 and with reference to the position in the cut. The curvature of the web 2 can be changed by changing the distance. In this way, different deformations of the material web 2 can be adjusted depending on the application.

After the cutting has been performed, the material web 2 is transferred to a guide plate 7 of the guide-out type. As can be seen from fig. 3, there is a gap between the guide plate 7 and the anvil plate 6. In order to prevent the front region of web 2 from running with anvil 6, thereby allowing web 2 to enter the gap between guide plate 7 and anvil 6, web 2 is lifted radially by lifter 11 after cutting. After cutting, the anvil 6 and the drum 5 are rotated further such that the presser 9 loses contact with the web 2, as shown in fig. 3. The presser 9 then no longer presses against the upper flat side of the web 2 and/or no longer presses the web 2 in the direction of the anvil drum, whereby the web 2 can be erected again in the front region on the basis of the lifter 11. The leading region of web 2 is then radially spaced from anvil drum 6. In this way, the front region of web 2 can be transferred or handed over to a guiding guide plate 7, wherein web 2 is effectively prevented from running with anvil drum 6. The web 2 can now no longer enter into the gap between the guide plate 7 and the anvil drum 6 undesirably.

The transverse cutting device 1 shown in fig. 3 represents a second possible arrangement of the compressor 9. The knife drum 5 has a presser 9 before the knife 8 and a presser 9 after the knife 8 in the transport direction 10 of the web 2. During the cutting process, web 2 is stabilized on both sides of knife 8 by two compactors 9, so that the cutting quality can be additionally improved.

The lifter 11 of the anvil drum 6 may, as seen in fig. 4, have an extension over a large part of the circumference of the anvil drum 6. The anvil drum shown in fig. 4 can be produced in a simple manner by means of a milling process. The lifter 11 is formed by milling into a circumferential groove. Only in the cutting area, in which the cutting and pressing of the web is done by the presser 9, the lifter 11 has to be peeled off locally from the anvil drum. This exfoliation may also be accomplished by milling.

As can be seen in fig. 4, the guide plate 7 has a plurality of recesses 12 or grooves. Each recess 12 is associated with a lifter 11, wherein each lifter 11 is guided through the respective recess of the guide plate 7 during rotation of the drum. In this way, the collision of the lifter 11 with the guide plate 7 is eliminated. The lifter 11 can thus hand the web 2 over to the guide plate 7 and guide it through the recess 12 in a safe manner. Lifter 11 therefore has the function of not only stabilizing web 2 during cutting, interacting with presser 9, but also of transferring web 2 to guide plate 7 for leadability in a safe manner.

List of reference numerals

1. Transverse cutting device

2. Web of material

3. Sheet

4. Guide plate

5. Knife drum

6. Anvil drum

7. Guide plate

8. Cutting tool

9. Compressing device

10. Direction of transport

11. Lifting device

12. Hollow part

Claims

1. A cross cutting device (1) for cutting or cross-separating a running web (2) into sheets (3), having: a knife drum (5) which can be rotated about a rotational axis extending transversely to the material web (2) and the transport direction thereof as a rotatable cutting device, wherein the knife drum (5) has at least one knife (8) which extends in the axial direction of the knife drum (5) and rotates with the knife drum (5); a corresponding anvil drum (6) which can be rotated about a rotational axis extending transversely to the material web (2) and its transport direction, wherein a press cut along the cutting line is carried out when the knives (8) of the knife drum (5) come into contact with the anvil drum (6), wherein the knife drum (5) has at least one presser (9) on its circumference in the transport direction (10) of the material web (2) in front of the knives (8),

wherein the presser (9) has a distance and/or a radial extent from the knife (8), so that the web (2) is in contact with the presser (9) during the press-cutting and is arched by the presser (9) in the direction of the anvil drum (6),

wherein the anvil drum (6) has at least one lifter (11) in the transport direction (10) of the web (2) before the cutting line to stabilize the web (2) during the cutting process,

characterized in that the lifter (11) is arranged at least substantially before the presser (9) in the transport direction (10) of the material web (2) in the movement condition of the cooperating knife drum (5) and anvil drum (6),

wherein the lifter (11) is spaced further from the cutting line than the presser (9) in the transport direction of the material web (2) during cutting,

wherein the distance between the lifter (11) and the presser (9) is at least 2 mm.

2. A cross cutting device (1) according to claim 1, wherein the web (2) is pressed by the presser (9) towards the anvil drum (6) and against the anvil drum (6) during the press cutting.

3. The cross cutting device (1) according to claim 1 or 2, wherein the material web (2) is made of paper, cardboard, plastic and/or metal.

4. Transverse cutting device (1) according to claim 1 or 2, characterized in that the anvil drum (6) is arranged vertically below the cutter drum (5).

5. A cross cutting device (1) according to claim 1 or 2, wherein a plurality of lifters (11) spaced apart from each other and/or pressers (9) spaced apart from each other are provided transversely to the web (2) and its conveying direction.

6. A cross cutting device (1) according to claim 1 or 2, wherein the knife drum (5) has at least one presser (9) on its circumference after the knife (8) in the transport direction (10) of the material web (2).

7. A transverse cutting device (1) according to claim 1 or 2, characterized in that the presser (9) and the lifter (11) are arranged in engagement with each other in the press-cutting at least in the edge region.

8. The transverse cutting device (1) according to claim 1 or 2, characterized in that the lifter (11) and/or the presser (9) are made of an elastic material.

9. The transverse cutting device (1) according to claim 1 or 2, characterized in that at least one guide plate (7) for receiving cut sheets (3) is arranged after the anvil drum (6) in the transport direction (10) of the web (2).

10. A transverse cutting device (1) according to claim 9, characterized in that the guide plate (7) has at least one recess or slot on the side facing the anvil drum (6), and that the lifter (11) is guided through the recess or slot when the anvil drum (6) is rotated.

11. Method for stabilizing the cutting edge during pinch cutting, wherein the pinch cutting is carried out with a transverse cutting device (1) according to one of the preceding claims, characterized in that the web (2) is in contact with at least one presser (9) of the knife drum (5) of the transverse cutting device (1) in the region of the newly formed front edge during the pinch cutting at the time of cutting, and is arched by the presser (9) in the direction of the anvil drum (6) of the transverse cutting device (1).

12. Method according to claim 11, characterized in that the material web (2) is brought into contact with at least one lifter (11) of the anvil drum (6) in the region before the newly formed leading edge at the time of cutting during the press cutting and is lifted by the lifter (11) in the direction of the knife drum (5).

13. Method according to claim 12, wherein the material web (2) is arched in an S-shape in the region between the lifter (11) and the presser (9).