EP3546161B1 - Cutting post post for mounting on a cutter device and cutter device comprising the same cutting post - Google Patents

Description

The invention relates to a cutting post for mounting on a cutting device and a cutting device with at least one cutting blade and with at least one such cutting post.

Packaging machines are used to produce product packaging in order to form the packaging from plastic films in several process steps, fill it with a product and then seal it if necessary. In one of the last steps of such a manufacturing process, the packaging is usually separated from a large section of film. Cutting devices are provided for this purpose in the packaging machines.

Such cutting devices have a cutting contour that specifies the geometry and size of the product packaging to be cut out. In the case of more complex or even angular cutting contours in particular, an arrangement of a plurality of cutting blades is necessary in order to be able to depict the cutting contour. When the cutting knives are arranged relative to one another, gaps form between the cutting knives due to the usual manufacturing tolerances. The interruptions in the cutting contour mean that the packaging is not cut at the impact points of the cutting blades, particularly in the corner areas of the cutting contour. The disadvantage is that unwanted threads form at the uncut points. Possibly even rip out the packaging in the appropriate places. Such defects in the packaging lead to a high level of production rejects and thus cause high production costs.

It is true that cutting devices are also known in which the cutting blades are welded to one another in order to avoid the disadvantages mentioned. However, the production of a welded cutting contour is very complicated and expensive. The maintenance of such a cutting device is also disadvantageous. If only one cutting blade is defective, all of the cutting blades that are welded together still have to be replaced.

From the US 3,263,547A a cutting device is known in which individual cutting blades meet at cutting posts. The substantially cylindrical cutting posts have grooves on their peripheral surface which receive the lateral edges of the adjacent cutting blades. On the end face of the respective cutting post, cutting edge sections are formed which, in various configurations, continue the course of the approaching cutting knife edges in the form of deflections, crossings or the like lying in a common plane. The cutting knives are brazed or welded to the respective cutting post. An interchangeability of individual parts is not given. The design is tailored to cutting plywood and other wood-like materials. However, the cutting behavior in corner areas and crossing points is problematic, at least with different, difficult materials such as tough foils.

The invention is based on the object of specifying a cutting post which enables simple assembly of cutting blades while at the same time allowing packaging to be cut out precisely.

This object is solved by a cutting post having the features of claim 1.

The invention is also based on the object of creating a cutting device that enables simple assembly of cutting blades while at the same time allowing packaging to be cut out precisely.

This object is achieved by a cutting device having the features of claim 7.

The cutting post according to the invention for mounting on a cutting device comprises at least one receptacle for a cutting knife and at least one cutting element with a cutting edge arranged at its head end. In addition to at least one cutting blade, the cutting post is part of the cutting device according to the invention. The at least one cutting blade has a cutting blade edge and is retained within the receptacle of the at least one cutting post. The cutting blade edge of the cutting blade and the cutting edge of the cutting element of the cutting post form a continuous cutting contour.

The cutting blade can be arranged and held in a predefined position relative to the cutting post by means of the receptacle of the cutting post.

The cutting post and the cutting blade are arranged relative to each other in such a way that the cutting edge of the cutting blade forms a continuous cutting contour with the cutting edge of the cutting element of the cutting post. Gaps in the cutting contour, in particular between the cutting post and the cutting blade, can be avoided. As a result, packaging can be completely cut out along the entire cutting contour of the cutting device. Uncut sections along the packaging outline, which lead to thread formation or even tearing of the packaging edges, can thus be avoided. In addition, crossing and node points of a cutting contour can be realized without gaps. The cutting posts and cutting blades are individually interchangeable, greatly simplifying geometry adjustments, maintenance and repairs.

The cutting blade can be positioned on the cutting post in a simple manner by the receptacle provided on the cutting post. A continuous cutting contour can be formed in a comparatively simple manner when the cutting post and cutting blade are mounted on the cutting device.

The receptacle for the cutting blade is preferably designed as a groove on a peripheral side of the cutting post, which runs in the direction of the longitudinal axis of the cutting post. Through the groove in the cutting post, the cutting post can be pushed onto the cutting knife in the longitudinal direction of the cutting post during assembly. The cutting blade protrudes into the groove of the cutting post. The cutting blade is thus positively fixed in the groove. The cutting post supports the cutting blade mounted in the groove against lateral forces that can occur, for example, during the cutting process. In addition, the groove of the cutting post allows the cutting blade and cutting post to be plugged onto one another, as a result of which a comparatively low assembly outlay can be ensured.

The cutting post preferably has several and in particular three or four receptacles for one cutting blade each. Advantageously, the cutting post also comprises, at its head end, cutting elements assigned to the respective receptacles, each with a cutting edge. If several cutting blades and several cutting posts are connected to one another, the cutting posts preferably form the nodal points of the cutting contours formed. By arranging several cutting posts and cutting knives, different cutting contours can be formed, which can be configured in different geometries and sizes. If, for example, four receptacles for cutting knives are provided at equal angular distances from one another on cutting posts, square and/or rectangular cutting contours can be formed. If, for example, only three receptacles are provided, the cutting blades can be arranged relative to one another in a honeycomb structure. Because the cutting posts act as nodes, the cutting blade edges of the various Combining cutting blades with the cutting edges of the cutting posts to form a continuous cutting contour ensures that packaging can be cut out precisely, even with such complex structures.

According to the invention, a cutting tip tapering in the direction from the foot end to the head end is formed at the head end of the cutting post. The cutting tip is preferably formed by the cutting edge of the at least one cutting element. The cutting edge ends in the cutting tip. The cutting edge of the at least one cutting element preferably encloses an angle with a straight line which runs parallel to the longitudinal axis of the cutting post. This angle opens towards the base end of the cutting post and is less than 90°, more preferably less than 60° and more preferably about 45°.

Consequently, during the cutting process, the packaging film is first contacted by the cutting tip and only then, followed by the rest of the cutting contour. As a result, the packaging film is first punctured by the cutting tip and cut out from there along the cutting contour. By puncturing the film, the packaging can be cut out even with low cutting forces, so that the packaging film neither warps nor overstretches.

It is advantageously provided that the at least one cutting element of the cutting post protrudes beyond the receptacle for the cutting blade in the radial direction, starting from the longitudinal axis of the cutting post. If the blade is held in the receptacle of the cutting post, the cutting element of the at least one cutting post and the cutting blade overlap. When assembled, the cutting post and cutting blade make contact in the overlap. On the one hand, the overlap acts as a form-fit hold-down device for the cutting blade, so that the cutting post and the cutting blade are precisely positioned relative to one another in the longitudinal direction of the cutting post. On the other hand, this creates a seamless transition between the cutting edge of the cutting post and the cutting blade edge of the cutting blade guaranteed. The overlap between the cutting post and the cutting blade serves to fix the cutting blade in the longitudinal direction while at the same time forming a continuous cutting contour.

Another component of the cutting device is advantageously at least one corner post. The corner post has at least one groove for receiving a cutting blade but no associated cutting element. Such corner posts can, in particular, accommodate and support cutting blades that are provided as edge elements. A continuation of the cutting contour is not necessary at such edge regions. It is therefore sufficient to provide the comparatively inexpensive corner posts without cutting elements.

The cutting device preferably comprises a base plate, with a plurality of cutting knives and a plurality of cutting posts being attached to the base plate in a modular manner, so that they can be detached and replaced. Due to the modular creation of the cutting contour from cutting knives and cutting posts, individual cutting contours can be created from the same basic elements and, if necessary, also changed. If a cutting knife or a cutting post needs maintenance or is even defective, it is sufficient to simply exchange the affected element of the cutting device for an intact element. It is not necessary to change the entire cutting device. In addition, for example after a cutting device has been shut down, its cutting blades and cutting posts can be reused in another cutting device.

Fig. 1

in einer perspektivischen Darstellung eine erfindungsgemäße Schneidvorrichtung mit Schneidmessern und mit Schneidpfosten,

Fig. 2

in einer perspektivischen Darstellung einen erfindungsgemäßen Schneidpfosten nach Fig. 1 mit Einzelheiten zu dessen geometrischer Ausgestaltung,

Fig. 3

in einer perspektivischen Darstellung von unten den Schneidpfosten nach Fig. 2,

Fig. 4

in einer perspektivischen Darstellung eine als Eckpfosten ausgeführte Variante des Schneidpfostens nach den vorhergehenden Figuren, jedoch ohne Schneidkanten,

Fig. 5

in einer perspektivischen, schematischen Schnittdarstellung die Schneidvorrichtung nach Fig. 1 vor dem Kontakt mit der zu schneidenden Folie,

Fig. 6

die Anordnung nach Fig. 5 mit in die Folie eingestochenen Schneidspitzen der Schneidpfosten,

Fig. 7

die Anordnung nach den Fig. 5, 6 mit weiter abgesenkten, die Folie durchtrennenden Schneidmessern,

Fig. 8

in einer perspektivischen Darstellung eine Ausführungsvariante der Anordnung nach den Fig. 1 bis 7 mit einer Schneidkontur in einer mehrfachen Rechteckstruktur,

Fig. 9

in einer perspektivischen Darstellung eine weitere Ausführungsvariante mit einer Schneidkontur in einer Wabenstruktur und mit Eckpfosten nach Fig. 4.

Exemplary embodiments of the invention are explained below with reference to the drawing. Show it:

1

in a perspective view a cutting device according to the invention with cutting knives and with cutting posts,

2

in a perspective view after a cutting post according to the invention 1 with details of its geometric design,

3

in a bottom perspective view of the cutting post 2 ,

4

in a perspective view, a variant of the cutting post designed as a corner post according to the previous figures, but without cutting edges,

figure 5

in a perspective, schematic sectional view of the cutting device 1 before contact with the film to be cut,

6

according to the arrangement figure 5 with the cutting tips of the cutting posts pierced into the foil,

7

the arrangement according to the Figures 5, 6 with further lowered cutting knives cutting through the foil,

8

in a perspective view an embodiment of the arrangement according to Figures 1 to 7 with a cutting contour in a multiple rectangular structure,

9

in a perspective representation, a further variant with a cutting contour in a honeycomb structure and with corner posts 4 .

1 shows a cutting device designed according to the invention in a perspective view. The cutting device 1 is part of a packaging machine, not shown, and is used here to cut out packaging. Such packaging is made of plastic film, which is usually provided in the form of film webs. The plastic film is deep-drawn in the packaging machine, for example by means of a vacuum deep-drawing process, into a corresponding packaging shape, for example a bag shape. The packaging form is then filled with the product to be packaged and sealed with a second plastic film. With the aid of the cutting device 1, one of the last process steps is carried out, namely the separation of the filled packaging from the film web. Water-soluble plastics such as polyvinyl alcohol (PVOH) are particularly suitable as packaging materials, but water-insoluble plastics can also be used to produce such packaging. The packaging can be used for cleaning or washing agents, for example, both in powder form and in used in liquid form. Such packaging is also suitable for use in the pharmaceutical sector for packaging medicinal products.

The cutting device 1 has an upper part 23 and a lower part 24 . in the in 1 shown embodiment, the upper part 23 comprises four cutting posts 2 and four cutting knives 4. The cutting posts 2 and the cutting knives 4 are mounted on a base plate, not shown. Receptacles 11 are formed on the cutting post 2, on which the cutting blades 4 are held in a form-fitting manner. A cutting blade edge 15 is formed on each of the cutting blades 4 . The cutting posts 2 include cutting elements 12, on each of which a cutting edge 13 is formed ( figure 5 ). The cutting edges 13 of the cutting posts 2 and the cutting knife edges 15 of the cutting knives 4 form a continuous cutting contour 16. In the exemplary embodiment according to FIG figure 1 the cutting blade 4 and the cutting post 2 are arranged alternately to one another in such a way that the cutting contour 16 has a rectangular shape.

The lower part 24 comprises a mold plate 17 which has a trough 18 . The trough 18 is used to shape the packaging in one of the upstream process steps of the packaging system. Appropriate packaging is in 1 shown schematically as packaging film 5. Cutting slots 19 are formed in the mold plate 17 and are arranged in a rectangle running around the trough 18 and corresponding to the rectangular shape of the cutting contour 16 .

In order to cut the packaging film 5 according to the cutting contour 16 of the upper part 23, the lower part 24 and the upper part 23 are moved together. The cutting contour 16 of the upper part 23 dips into the cutting slots 19 of the lower part 24 and cuts through the packaging film 5 . If the packaging film 5 is cut, upper part 23 and lower part 24 are moved apart again. The cutting posts 2 and cutting blades 4 are withdrawn from the cutting slots 19 of the base 24.

In the Figures 2 and 3 is the cutting post 2 designed according to the invention 1 shown. The cutting post 2 extends along its longitudinal axis 7 from its foot end 9 to its head end 8.

The cutting post 2 has a first section 25 and a second section 26. The cutting post 2 is formed along the first section 25, which extends from the foot end 9 to the second section 26, as a substantially cylindrical body of revolution. Along the second section 26, which extends from the first section 25 to the head end 8, the cutting post 2 is formed from four plate-shaped cutting elements 12, each with a cutting edge 13. The cutting elements 12 are arranged relative to one another in such a way that their cutting edges 13 converge in the longitudinal axis 7 .

The cutting edges 13 of the cutting elements 12 are inclined relative to the longitudinal axis 7 and jointly terminate in a cutting tip 14 . The cutting edges 13 enclose an angle α with the longitudinal axis 7 of the cutting post 2 which is open towards the foot end 9 of the cutting post 2 . The angle α is less than 90°, in particular less than 60°, in the preferred exemplary embodiment approximately 45°.

As in the Figures 2 and 3 shown, the cutting post 2 has a peripheral side 10 on which four receptacles 11 for mounting the cutting blades 4 are formed. In the preferred exemplary embodiment, the receptacles 11 are designed as grooves that run in the direction of the longitudinal axis 7 . The grooves extend from the foot end 9 of the cutting post 2 to the cutting element 12. The groove is delimited by a first bearing surface 21, which is formed on the side of the cutting element 12 facing the foot end 9. When mounting the cutting post 2 on the cutting blade 4 , the cutting post 2 can be pushed onto the cutting blade 4 at its groove until the cutting post 2 comes into contact with the cutting blade 4 with its first bearing surface 21 . The first bearing surface 21 accordingly forms a vertical stop between the cutting post 2 and the cutting knife 4 in Direction of the longitudinal axis 7. In addition, a second contact surface 22 is formed on the cutting element, which, starting from the longitudinal axis 7, serves as a horizontal stop between the cutting post 2 and the cutting blade 4 in the radial direction.

The four receptacles 11 are arranged in the circumferential direction of the cutting post 2 at equal angular intervals. Thus, the angular distance β between the adjacent shots 11 is in the Figures 2 and 3 shown cutting post 90°. The cutting elements 12 are aligned at the same angular distances as the receptacles 11, so that in each case adjacent cutting elements 12 with the cutting edges 13 have the angular distance β of 90° from one another.

Thereby the cutting posts 2 in arrangement with the cutting knives 4 mounted on the base plate form a rectangular structure. In an alternative embodiment variant of the cutting device 1 that is not shown, the angular distance β between adjacent receptacles 11 and adjacent cutting elements 12 can differ from one another. In this way, for example, diamond or parallelogram shapes or other structures can be created.

In 4 a corner post 3 is shown. The corner post 3 has a receptacle 11 which is designed as a groove in the exemplary embodiment. As in the case of the cutting post 2 , the groove runs along the longitudinal axis 7 ′ of the corner post 3 . Like the cutting post 2, the corner post can be pushed with its groove 11 onto the cutting blade 4 until the latter comes to rest on the first bearing surface 21'. The corner posts do not have cutting elements 12. The corner posts 3 only serve to support the cutting knives 4 which are arranged at the edge regions of a cutting pattern.

In the Figures 5 to 7 are schematic sectional views of the cutting device according to FIG 1 shown, which illustrate the cutting process in step-by-step images. In figure 5 are the upper part 23 and the lower part 24 still in the starting position. Already in 6 are upper part 23 and lower part 24 moved together so far that the cutting tips 14 pierce the packaging film 5. The cutting post 2 dips into the cutting slots 19 with its second section 26 , namely with its cutting elements 12 . The packaging film 5 is then incised by the cutting edges 13 . The cutting blade edges 15 of the cutting elements 4 do not yet protrude into the cutting slots 19. Only in 7 the upper part 25 and the lower part 26 are fully retracted. The cutting knives 4 are immersed in the cutting slots 19 and the packaging film 5 is cut out. The upper part 23 and the lower part 24 are then moved apart again.

In the embodiment according to the cutting device according to 1 the cutting knife edges 15 have a corrugation or a serrated edge, which extends exclusively in the plane of the respective cutting knife, ie has no wave shape transversely thereto. As a result, the cutting forces on the packaging film 5 can be reduced, so that stretching or warping of the packaging film 5 is avoided. At the same time, the cutting lines and thus the outlines of the packaging that has been cut out are formed in a straight line.

In 8 is an arrangement of several cutting posts 2 and several cutting knives 4 as a variant of the arrangement 1 shown with multiple repeating rectangular cutting contour 16. The cutting post 2 have in accordance with the Figures 2, 3 each four recordings 11 and four cutting elements 12 on. The receptacles 11 adjacent to one another and the cutting elements 12 adjacent to one another each have an angular spacing β of 90°. This requires a square, at least rectangular arrangement of the cutting posts 2 and the cutting blades 4.

In 9 a further exemplary embodiment of an arrangement of a plurality of cutting posts 2 and a plurality of cutting blades 4 is shown, with a plurality of corner posts 3 also being used here in addition. The cutting posts 2 each have three receptacles 11 and three cutting elements 12 here. The receptacles 11 adjacent to one another and the cutting elements 12 adjacent to one another each have an angular spacing β of 120°. This results in a honeycomb arrangement of the cutting posts 2 and the cutting blades 4 and a corresponding honeycomb cutting pattern. The cutting blades 4 are held on corner posts 3 at the edge regions of the arrangement.

The patterns according to figures 8 and 9 can be expanded or reduced as desired by adding additional cutting knives 4, cutting posts 2 and corner posts 3. The cutting posts 2 serve as connecting elements for the cutting blades 4. In addition to the embodiment according to FIG 2 Here the cutting posts not only function as corner posts, but also as node or crossing points for the individual cutting lines. The cutting posts 2 ensure a continuous, gap-free cutting contour 16 throughout by connecting several cutting knife edges 15 to one another via the cutting edges 13 of the cutting elements 12.

Claims (12)

1. Cutting post for assembling on a cutting device, wherein the cutting post (2) extends along a longitudinal axis (7) and comprises a head end (8) and a foot end (9), wherein the cutting post (2) comprises at least one receptacle (11) for a cutting blade (4) and at least one cutting element (12) which is disposed on the head end (8) and has a cutting edge (13),
   characterized in that a cutting tip (14) which tapers in the direction from the foot end (9) towards the head end (9) is configured on the head end (8) of the cutting post (2).
2. Cutting post according to Claim 1,
   characterized in that the receptacle (11) for the cutting blade is configured as a groove on a circumferential side (10) of the cutting post (2), said groove running in the direction of the longitudinal axis (7) of the cutting post (2).
3. Cutting post according to Claim 1 or 2, characterized in that the cutting post (2) has a plurality of, in particular three or four, receptacles (11) for in each case one cutting blade (4), and in that the cutting post (2) on the head end (8) thereof moreover comprises cutting elements (12) which are assigned to the respective receptacles (11) and have in each case one cutting edge (13).
4. Cutting post according to Claim 1,
   characterized in that the cutting edge (13) of the at least one cutting element (12) ends in the cutting tip (14).
5. Cutting post according to one of Claims 1 to 4, characterized in that the cutting edge (13) of the at least one cutting element (12), conjointly with a straight line that runs parallel to the longitudinal axis (7) of the cutting post (12), includes an angle (α), wherein the angle (α) is open towards the foot end (9) of the cutting post (2), and wherein the angle (α) is smaller than 90°, in particular smaller than 60°, and in particular is approximately 45°.
6. Cutting post according to one of Claims 1 to 5, characterized in that the at least one cutting element (12), proceeding from the longitudinal axis (7) of the cutting post (2), protrudes in the radial direction beyond the receptacle (11) for the cutting blade (4).
7. Cutting device having at least one cutting blade (4) and having at least one cutting post (2) according to one of Claims 1 to 6, wherein the at least one cutting blade (4) has a cutting blade edge (15) and is held in the receptacle (2) of the at least one cutting post (2), wherein the cutting blade edge (15) of the cutting blade (4) and the cutting blade edge (13) of the cutting element (12) of the cutting post (2) form a continuous cutting contour (16).
8. Cutting device according to Claim 7,
   characterized in that the receptacle (11) is configured as a groove, and in that the at least one cutting blade (4) protrudes into the groove of the at least one cutting post (2).
9. Cutting device according to Claim 7 or 8, characterized in that the cutting element (12) of the at least one cutting post (2) and the cutting blade (4) overlap each other.
10. Cutting device according to one of Claims 7 to 9, characterized in that the cutting device (1) comprises at least one corner post (3), wherein the corner post (3) has at least one groove (11) for receiving a cutting blade (4) and no assigned cutting element (12).
11. Cutting device according to one of Claims 7 to 10, characterized in that a plurality of cutting blades (4) and a plurality of cutting posts (2) are connected to one another in such a manner that the cutting posts (2) form nodes of cutting contours (16).
12. Cutting device according to one of Claims 7 to 11, characterized in that the cutting device (1) comprises a base plate, wherein a plurality of cutting blades (4) and a plurality of cutting posts (2) in the manner of modules are fastened so as to be releasable and interchangeable on the base plate.

Images