EP3848169A1 - Perforating knife with crimping surface - Google Patents

Abstract

The invention relates to a perforating knife 1 for perforating at least one layer of a printing material to be processed into a printed product. The object of the invention is to create a solution with which the interlocking effect between the perforated printing material layers can be improved. This object is achieved by a device according to Claim 1 solved. The device according to the invention comprises a perforating knife 1, in which a crimping surface 5 adjoins the base point 4 of the perforating tip 3 on at least one side of the perforating tip 3.

Description

The invention relates to a perforating knife for perforating at least one layer of a printing material to be processed into a printed product, the perforating knife having a plurality of perforating elements on the circumference, wherein a perforating element comprises at least one perforating tip which extends radially from an outer radius to at least one on one first radius lying base extends. The invention also relates to a method for operating a perforating knife.

In the folding units of web printing machines or in various folding or post-processing machines, perforation devices are used which perforate the at least one layer of the printing material, which usually moves in one transport direction. If the printing material is perforated transversely to the transport direction, so-called transverse perforations are used for this purpose, in which the actual perforating knife has a sheet metal strip with at least one edge formed with a perforation toothing.

If the printing material is perforated in the transport direction, so-called longitudinal perforations are used for this purpose, in which the perforating knife is usually designed as a circular knife which has perforating teeth on at least part of its circumferential surface. This perforation toothing usually consists of pointed teeth which pierce the at least one layer of the printing material to be perforated. For this purpose, the perforating knife, which is mostly driven in rotation, interacts with a counter-knife which has either a groove or an at least partially relatively soft and elastic surface and serves as an abutment for the printing material to be perforated.

A large number of perforating knives are known from the prior art, which have a large number of pointed perforating teeth on at least part of their effective surface, in the case of circular knives this is the outer circumferential surface.

Since the perforating teeth in the perforating knives known from the prior art essentially have the shape of a triangle, the perforation intensity can thus be varied via the penetration depth of the perforating teeth into the printing material to be perforated.

Furthermore, it is known from the prior art that by perforating a plurality of layers of printing material lying one above the other, these are linked to one another by joint piercing, so that the individual layers of printing material are fixed in their position relative to one another. This effect is used, for example, in the production of book blocks, without being limited to this, so that the respective layers of printing material are fixed to one another so that, for example, when the individual book blocks are brought together to form a book, a constant margin around the text page can be implemented.

However, the interlinking effect of perforating knives known from the prior art is heavily dependent, among other things, on the respective type of paper, the number of printing material layers to be interlinked and the geometry of the perforating teeth.

The invention is therefore based on the object of creating a solution with which the interlinking effect between the perforated layers of printing material can be improved.

This object is achieved by a device according to claim 1. The device according to the invention comprises a perforating knife, in which on at least one side of the perforating tip a crimping surface adjoins the base point of the perforating tip.

Such a perforating knife has the advantage that at least after perforation, i.e. after piercing the printing material layers through each perforating tip, through which a small bead arises in each printing material layer, which fix the individual printing material layers to one another, the overlying printing material layers with the crimping surface directly are pressed together again after the perforation process, which significantly increases the intensity of the linking.

A perforating knife according to the invention thus has a crimping surface after the perforating tip, viewed in the direction of rotation, which, viewed in the circumferential direction, has a limited extension, which is generally 2 to 10 mm. In this way, the area around a perforation hole can be pressed together again, so that the beads of the respective layers of printing material are linked or "felted" with one another even more intensively.

The crimping surface can have the contour of a circular arc which extends on a constant first radius concentrically to the center of the perforating knife. Thus, the area is evenly pressed together immediately after the perforation. The intensity of the interlinking can be varied by changing the pressure between the perforating knife and the abutment.

In a further embodiment of the invention, at least one crimping surface has an inclination angle α to the circle spanned by the first radius, so that the crimping surface has an inclination towards a concentric circular arc. This offers the advantage that, due to the inclination of the crimping surface to a concentric circle described by the first radius, the intensity of the interlinking in interaction with the abutment can be varied better.

Fig. 1

ein beispielhaftes Perforiermesser

Fig. 2

ein beispielhaftes Perforierelement des Perforiermessers in Detailansicht

Fig. 3

eine mögliche Ausgestaltung eines Perforierelementes

Fig. 4

eine mögliche Ausgestaltung eines Perforierelementes, bei welcher die Crimpfläche einen Neigungswinkel aufweist

Fig. 5

eine mögliche Ausgestaltung eines Perforierelementes mit Crimpflächen zu beiden Seiten der Perforierspitze

Fig. 6

eine mögliche Ausgestaltung eines Perforierelementes mit zwei Perforierspitzen

Preferred developments of the inventions emerge from the dependent claims and the following description. Various exemplary embodiments of the invention are explained in more detail with reference to the drawings, without being restricted thereto. It shows:

Fig. 1

an exemplary perforating knife

Fig. 2

an exemplary perforating element of the perforating knife in a detailed view

Fig. 3

a possible design of a perforating element

Fig. 4

a possible configuration of a perforating element in which the crimping surface has an angle of inclination

Fig. 5

a possible configuration of a perforating element with crimping surfaces on both sides of the perforating tip

Fig. 6

a possible embodiment of a perforating element with two perforating tips

Fig. 1 shows a perforating knife 1 according to the invention, which is designed as a circular knife. Such a perforating knife 1 is used to perforate at least one layer of a printing material to be processed into a printed product, for this purpose the perforating knife 1 is received in a rotatably driven holder and is in operative connection with a rotating abutment (not shown). The printing material to be perforated is supported by the rotating abutment, so that the perforating tips 3 can pierce and thus perforate the printing material to be perforated.

This in Fig. 1 The perforating knife 1 shown is mostly made from sheet steel and has a thickness of usually 0.5 millimeters to usually a maximum of 2 millimeters and is usually produced by laser cutting and / or by grinding. The perforating tips 3 can also be touched towards the plane of the drawing, but this is irrelevant for the present invention. The perforating knife 1 can be hardened or tempered in its entirety, but it is also possible to harden or temper only the perforating tips 3 or the perforating tips 3 and the crimping surfaces 5.

The perforating knife 1 has a plurality of perforating elements 2 on the circumference. If a printing material or a preproduct made from it, which usually consists of several layers of printing material lying one above the other, is only to be perforated over a first partial length and not perforated over a second partial length, it is also possible, albeit in Fig. 1 not shown, that a perforating knife 1 has such perforating elements 2 only on one or more first subsections and has no perforating elements 2 on one or more second subsections.

This in Fig. 1 The perforating knife 1 shown has a defined circular shape, the outer envelope being defined by a defined outer radius Ra.

Furthermore, due to the geometry of the perforating elements 2, the in Fig. 1 Perforating knife 1 shown has a defined direction of rotation 7 in order to ensure a particularly advantageous effect during operation. The distance between the perforations is determined by the distance between the perforating elements 2 in the circumferential direction of the outer circle.

Fig. 2 shows the detailed view of the in Fig. 1 Area of a perforating element 2 shown as X on an enlarged scale.

Fig. 2 thus shows in enlarged form an exemplary embodiment of a perforating element 2, the in Fig. 2 The perforating element 2 shown comprises a perforating tip 3 with a base point 4 and an adjoining crimping surface 5, the crimping surface 5 being connected to the base point 4 of the perforating tip 3.

Albeit in Fig. 2 shows by way of example only one configuration of a perforating element 2 with only one perforating tip 3 and one crimping surface 5, configurations with a plurality of perforating tips 3 and / or a plurality of crimping surfaces 5 are also possible.

Fig. 3 shows a further exemplary embodiment of a perforating element 2, as well as further details on the geometry of a perforating element 2.

How out Fig. 3 As can be seen, the perforating tip 3, that is to say the part of the perforating element 2 which, in use, pierces the at least one printing material layer or preferably pierces and thus perforates all of the printing material layers to be perforated, extends radially from the outer radius Ra to a first one Radius R1 arranged base point 4. The difference between the outer radius Ra and the first radius R1 thus defines the height of the perforating tip 3, which is usually in a range of approximately 1 millimeter to approximately 10 millimeters.

The in Fig. 3 The example shown adjoins one side of the perforating tip 3, namely on the side of the perforating tip 3 facing away from the direction of rotation 7, a crimping surface 5 which directly adjoins the base point 4 of the perforating tip 3.

Although Fig. 3 shows an embodiment with only one crimping surface 5 adjoining the perforating tip 3, it is also possible for several crimping surfaces 5 to adjoin a perforating tip 3, as shown and described below.

Such a crimping surface 5 has an extension which is limited in the circumferential direction and which is generally approximately between 2 and 10 millimeters.

Fig. 3 shows an embodiment of a perforating element 2 in which the crimping surface 5 extends over the first radius R1, that is, the crimping surface 5 has the shape of a segment of a circle which is defined by the first radius R1, so that when the perforating knife 1 each crimping surface 5 can roll in a longitudinal perforating device with a corresponding setting depth on the printing material to be perforated, which is not shown, after the printing material has been pierced by the perforating tips 3. Thus, with the appropriate setting depth, the layers of printing material that are already interlinked or interlinked by the perforation can be pressed together again after being pierced through each crimping surface 5 and pressed against the abutment (not shown) required for the perforation process, thereby creating the interlinking effect, which in bookbinders is also known as "felting "is known, is significantly amplified.

Fig. 4 shows a further exemplary embodiment of a perforating element 2, as well as details of an alternative geometry of a perforating element 2.

How also from Fig. 4 As can be seen, the perforating tip 3, that is, the part of the perforating element 2 which in use pierces the at least one printing substrate layer or preferably pierces and thus perforates all the printing substrate layers to be perforated, extends radially from the outer radius Ra to one a first radius R1 arranged base point 4. The The difference between the outer radius Ra and the first radius R1 thus defines the height of the perforating tip 3, which in this variant is usually in a range from approximately 1 millimeter to approximately 10 millimeters.

Even with the in Fig. 4 The example shown adjoins one side of the perforating tip 3, namely on the side of the perforating tip 3 facing away from the direction of rotation 7, a crimping surface 5 which directly adjoins the base point 4 of the perforating tip 3.

Although Fig. 4 shows an embodiment with only one crimping surface 5 adjoining the perforating tip 3, it is also possible for several crimping surfaces 5 to adjoin a perforating tip 3, as shown and described below. Such a crimping surface 5 has an extension which is limited in the circumferential direction and which is generally approximately between 2 and 10 millimeters.

Fig. 4 however, shows an alternative embodiment of a perforating element 2, in which the crimping surface 5 has an angle of inclination α to the circle 6 spanned by the first radius R1. Alternatively, the angle of inclination α can also be defined between the tangent (not shown in the drawing) and the crimping surface, which is adjacent to the circle 6 at the base point 4 of the perforating tip 3.

In contrast to the in Fig. 3 The embodiment of a perforating element 2 shown in the figure, the crimping surface 5 is thus not defined by the circle 6 defined by the first radius R1 or a circle segment contained therein, but rather has an inclination thereto. The angle of inclination α used there is in a range from 1 ° to approximately 45 °, preferably in a range from 10 ° to 30 °.

Due to the inclination of the crimping surface 5 to the circle 6 or tangents applied to it, the pressure and thus the crimping as well as the resulting interlocking or felting can be set finer by changing the position of the perforating knife 1 on the abutment.

As in the Figures 2 to 4 , as well as in the following Figures 5 and 6 As shown, the transition between the perforating tip 3 and the crimping surface 5 can be rounded, since this is advantageous both in terms of fatigue strength and in terms of production. The radii used here are usually in a range from approximately 0.1 millimeters to approximately 5 millimeters.

The ones in the Figures 2 to 4 The illustrated embodiments of perforating elements 2 have the common feature that each perforating element 2 has a perforating tip 3 on its leading side as seen in the direction of rotation 7, on which a crimping surface on the side opposite to the direction of rotation 7 or, in other words, on the side facing away from the direction of rotation 7 5 adjoins. Such a configuration has the advantage that after perforation has taken place in the layers of printing material lying one on top of the other, they are crimped in the sense of being pressed together by the subsequent crimping surface 5, which is advantageous for linking the layers of printing material to one another.

However, such perforating knives 1 require a firmly defined direction of rotation 7, which must be observed when installing the perforating knife 1 in a corresponding perforating device.

In order to avoid a special required direction of rotation 7, alternative embodiments with a symmetrical configuration of the perforating element 2 are therefore advantageous.

Fig. 5 shows an exemplary embodiment of a perforating element 2 according to the invention, which is attached to each in the direction of rotation 7 (see Fig. 1 ) seen leading and trailing side of the perforating element 2 each have a perforating tip 3. This in Fig. 5 The perforating element 2 of the perforating knife 1 shown thus points in the direction of rotation 7 (see FIG Fig. 1 ) has a first perforating tip 3-1, a first crimping surface 5-1 adjoining it, a second crimping surface 5-2 and an adjoining second perforating tip 3-2 and is therefore independent of the direction of rotation.

Albeit in Fig. 5 an embodiment is shown in which both the first crimping surface 5-1 and the second crimping surface 5-2 have an inclination relative to the circle 6 described by the first radius R1 or tangents applied thereto, as below Fig. 4 has described, it is also possible, although not shown in the drawing, that the first and / or the second crimping surface 5-1, 5-2 have the shape of a circular arc segment, which is defined by the radius R1, as in the description of the in Fig. 3 illustrated embodiment is explained.

Fig. 6 shows a further exemplary embodiment of a perforating element 2 according to the invention, which is attached to each in the direction of rotation 7 (see Fig. 1 ) seen leading and trailing side of the perforating element 2 each has a crimping surface 5. This in Fig. 6 The perforating element 2 of the perforating knife 1 shown thus points in the direction of rotation 7 (see FIG Fig. 1 ) seen a first crimping surface 5-1, an adjoining perforating tip 3 and an adjoining second crimping surface 5-2 and is thus also independent of the direction of rotation.

Albeit in Fig. 6 an embodiment is shown in which both the first crimping surface 5-1 and the second crimping surface 5-2 have an inclination relative to the circle 6 described by the first radius R1 or tangents applied thereto, as below Fig. 4 has described, it is also possible, although not shown in the drawing, that the first and / or the second crimping surface 5-1, 5-2 have the shape of a circular arc segment, which is defined by the radius R1, as in the description of the in Fig. 3 illustrated embodiment is explained.

Although in none of the Figures 1 to 6 shown in the drawing, it is also possible to use a perforating knife 1 with different configurations of the perforating elements 2, as in the FIGS Figures 3 to 6 shown and described, so that in a perforating knife 1 according to the invention not necessarily only a single embodiment of a perforating element 2 is used.

Even if the present invention is shown and explained exclusively on a perforating knife 1 designed as a circular knife, it is also possible to implement such perforating elements 2 with crimping surfaces 5 also on perforating knife strips with a perforating element 2 lying on a straight line, as is used for transverse perforations .

Although not shown in any of the figures, it is also possible to make a recess between a perforating tip 3 and the crimping surface 5 adjoining it in relation to the area of the crimping surface 5 with the first radius R1, comparable to an undercut. This means that in the area of the base point 4 of the perforating tip 3, a depression is made in relation to the area of the crimping surface 5 with the largest radius, which corresponds to the first radius R1. Such a depression has a width of approximately 0.1 millimeter to approximately one millimeter in the circumferential direction of the circle 6 described by the first radius R1, depending on the manufacturing process.

The crimping surface 5 thus still adjoins the respective adjacent perforating tip 3, although this may allow easier processing of the crimping surface 5 and / or the perforating tip 3.

In the Figures 1 to 6 versions of the perforating knife 1 according to the invention are shown in each case, in which there is a greater distance with a recess relative to the crimping surface 5 between the individual perforating elements 2. However, it is also possible for the perforating elements 2 to be arranged over on the active surface of the perforating knife 1 without a correspondingly larger spacing and / or without a corresponding depression.

The invention also encompasses a method of operating one as in FIG Figures 1 to 6 shown and described perforating knife 1, wherein the perforating knife 1 according to the invention is brought into operative connection with a grooved or with an elastic counter surface serving as an abutment for the printing material to be perforated, and wherein the distance between the perforating knife 1 and the counter surface serving as an abutment for the printing material can be changed.

List of reference symbols

1

Perforating knife

2

Perforating element

3

Perforating point

4th

Base point

5

Crimping surface

6th

circle

7th

Direction of rotation

Ra

Outer radius

R1

first radius

α

Tilt angle

Claims (11)

Perforating knife (1) for perforating at least one layer of a printing material to be processed into a printed product, the perforating knife (1) comprising a plurality of perforating elements (2) on the circumference, wherein a perforating element (2) comprises at least one perforating tip (3), which is extends radially from an outer radius (Ra) to at least one base point (4) lying on a first radius (R1), characterized in that a crimping surface (5) is attached to the base point (4) on at least one side of the perforating tip (3) connects. Perforating knife (1) according to Claim 1, characterized in that each crimping surface (5) has an extension limited in the circumferential direction. Perforating knife (1) according to one of Claims 1 to 2, characterized in that at least one crimping surface (5) extends on the first radius (R1). Perforating knife (1) according to one of Claims 1 to 2, characterized in that at least one crimping surface (5) has an angle of inclination α to the circle (6) spanned by the first radius (R1). Perforating knife (1) according to Claim 4, characterized in that the angle of inclination α is in a range from 1 ° to 45 °. Perforating knife (1) according to one of Claims 1 to 5, characterized in that the transition between the perforating tip (3) and at least one crimping surface (5) is rounded. Perforating knife (1) according to one of Claims 1 to 6, characterized in that between a perforating tip (3) and the crimping surface (5) adjoining it there is a recess in relation to the area of the crimping surface (5) is designed with the first radius (R1). Perforating knife (1) according to one of Claims 1 to 7, characterized in that each perforating element (2) has a perforating tip (3) on its leading side, seen in the direction of rotation (7), on which a crimping surface, seen opposite to the direction of rotation (7) (5) adjoins. Perforating knife (1) according to one of Claims 1 to 7, characterized in that each perforating element (2) has a perforating point (3) on each leading and trailing side as seen in the direction of rotation (7). Perforating knife (1) according to one of Claims 1 to 7, characterized in that each perforating element (2) has a perforating tip (3), which is adjoined by a crimping surface (5) on both sides. Method for operating a perforating knife (1) according to one of Claims 1 to 10, characterized in that the perforating knife (1) is brought into operative connection with a grooved or an elastic counter surface and the distance between the perforating knife (1) and the counter surface are changed can.

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