EP3524398A1 - Stamping device for producing form labels - Google Patents

Abstract

In a punching device for producing shaped labels from a starting stack (1, 1 ') of sheet-shaped Good comprising: a hollow cylindrical punching knife (2) and a lifting device (3) with a lifting plate (5) to a stack on the lifting plate (5) lying stack of benefits (4, 4 ') to push through the punching knife (2) by the output stack (1, 1') is pushed in a punching direction (A) against the punching knife (2); it is provided that the lifting plate (5) has a compensating body (6) on the cutting blade side, wherein the compensating body (6) is designed such that within a cutting contour (9) of the punching blade (2) and circumferentially spaced therefrom an elevation (10 ), which projects beyond a lifting plate plane (S) defined by the cutting contour (9).

Description

Technical area

The invention relates to an apparatus and a method for punching a stack of sheet-like material for the production of molded labels.

Technical background

For the production of shaped labels, the so-called piercing punching is often used. In this case, an output stack of sheet material is pushed with a lifting device against a hollow cylindrical punching knife, wherein a benefit stack, i. the stack of the finished form labels is formed, is pressed through the punching knife and the cut supernatant outside the punching knife is removed. The punched stack of benefits is automatically pushed further by the subsequent stack and then further conveyed by a downstream banding, again divided into individual benefit stack and provided with a band. When entering the punching knife in the output stack can - depending on the starting material and / or surface dimension of the benefit stack - the problem arise that bulge the upper sheet products of the stack (force or voltage discharge), which in the penetration process to inaccuracies in the shape of Labels and leads to an overhang of the benefit stack (situational puncture state).

In order to suppress the bulge during the penetration process to a large extent and thus to increase the accuracy of the punching, was in EP0735938 by the same Applicant proposed to press a ram on the opposite side of the lifting device on the stack to press the stack in a press-holding by the punching knife. Even higher accuracies were achieved with a press die, which fits precisely into the hollow cylindrical punching knife and thus a pressure on the entire Surface of the benefit stack. After punching the stack of benefits is pressed by the punch against the punching direction of the punching knife. A disadvantage of the earlier counter-pressure method, however, is the lower throughput rate, because the benefit stack ejected each by means of the punch from the punching knife and seen in the punching direction back and must be led away laterally to supply a Bandiervorrichtung, which ultimately reflected in higher production costs of the form of labels. In addition, such devices are much more expensive than devices without counter-pressure.

EP2944440 by the same Applicant corrects this disadvantage and describes a punching method with a counter-pressure device, in which the back pressure is applied to an already stamped, possibly at least partially protruding from the punch blade utility stack.

Presentation of the invention

It has now been found that in punching processes in which a punched stack of benefits is automatically pushed further by the subsequent stack of benefits, the subsequent stack of benefits, with or without counterpressure, may also have an overhang in the upper region (i.e., in the region that first drives into the punching knife). This was particularly evident in highly resilient output stacks of, for example, plastic films.

An object of the invention is to avoid the overhang in subsequent benefit stack. This object is achieved by a punching device according to claim 1.

The invention is based on the finding that the overhang is caused by a bulge due to the voltage discharge of the already completely or partially punched stack of benefits against the punching direction. A subsequent initial stack subsequently forms this bulge, which due to the curvature leads to an excessive punching of the uppermost layers of sheet-shaped material.

The punching device for producing shaped labels from a starting stack of sheet-shaped material comprises a hollow cylindrical punching knife and a lifting device with a lifting plate to press a stack of benefits resting on the lifting plate by the punching knife, in which the output stack is pushed in a punching direction against the punching knife. The lifting plate has a compensating body on the cutting blade side, wherein the compensating body is designed such that within a cutting contour of the punching blade and circumferentially spaced from this results in a survey that protrudes over a Hubplattenebene defined by the sectional contour. In other words, the expansion and arrangement of the compensation body is such that the compensation body is offset in relation to the sectional contour of the punching knife inwards.

By cutting contour is meant the contour or the outline, which (s) are perpendicular respectively by a projection of the cutting edge of the punching knife. results against the punching direction on the lifting plate. This sectional contour also corresponds to the contact line of the punching knife with the lifting plate when the lifting plate is guided to the punching knife. This contact line lies in the Hubplattenebene. The cut contour also defines the outer contour of the shape label.

Experiments have shown that after punching, the bottom layers of the starting stack are centered - i.e. within the cutting contour - pressed in the punching direction. In this case, the voltage in the last punched sheet-shaped Good of the stack of benefits discharges in the punching direction and bulging of the punched stack of benefits against the punching direction is prevented. A subsequent output stack can subsequently be pushed flat against the punching knife and there is no curvature of the uppermost layers of the output stack. An excess in the upper area of the subsequent benefit stack is thus prevented.

In some embodiments, the compensating body may be placed on or integrated with a planar surface of the lifting plate. The compensation body can be plugged or screwed as a replacement part. Alternatively, the balancing body and the lifting plate can be made in one piece be formed, in which case the lifting plate is preferably designed interchangeable.

In some embodiments, the compensating body and / or the lifting plate may be replaceably mounted in the lifting device. This allows easy replacement respectively. Adjusting the compensation body to a replaced punching knife.

In some embodiments, the balancing body may be in the form of a flat leveling pad.

In some embodiments, the compensating body may be in the form of a bulge with flattened sides merging into the lifting plate plane. Such laterally flattened compensating body allow a simpler pushing the output stack on the lifting plate.

In some embodiments, to form the compensating body, the lifting plate may have a circumferential groove surrounding the compensating body, which protrudes on both sides of the sectional contour.

In some embodiments, the lift plate may include a platen on which the balance body is disposed. This has the advantage that the lifting device can be easily adapted to changed punching blades.

In some embodiments, an outer contour of the compensating body relative to the sectional contour may be offset by at least 10 mm inwards. The compensating body may protrude at its thickest point 0.5 mm to 2 mm, preferably about 1 mm above the Hubplattenebene.

An exchangeable balancing body can be easily adapted to the needs and optimized with respect to the material to be punched and the shape of the resulting labels.

In all embodiments, both the support plate and the compensation body can be made of plastic, aluminum or steel.

Brief explanation of the figures

Fig. 1

unter (a) bis (f) schematische Darstellungen des Stanzvorgangs und der Ausbildung einer unerwünschten Ausbauchung eines Nutzenstapels;

Fig. 2

eine schematische Seitenansicht einer Hubplatte mit einem Ausgleichskörper;

Fig. 3

eine schematische Ansicht auf die Oberfläche einer Hubplatte mit Ausgleichskörper;

Fig. 4

eine schematische Seitenansicht einer Hubplatte mit einem abgeflachten Ausgleichskörper;

Fig. 5

eine schematische Ansicht einer gefrästen Hubplatte;

Fig. 6

eine schematische Ansicht einer Hubplatte mit Auflageplatte; und

Fig. 7

unter (a) bis (c) schematische Darstellungen des Stanzvorgangs mit einem Ausgleichskörper.

The invention will be explained in more detail below with reference to embodiments in connection with the (s) drawing (s). Show it:

Fig. 1

under (a) to (f) are schematic illustrations of the punching operation and the formation of an unwanted bulge of a benefit stack;

Fig. 2

a schematic side view of a lifting plate with a balancing body;

Fig. 3

a schematic view of the surface of a lifting plate with balancing body;

Fig. 4

a schematic side view of a lifting plate with a flattened compensating body;

Fig. 5

a schematic view of a milled lifting plate;

Fig. 6

a schematic view of a lifting plate with support plate; and

Fig. 7

under (a) to (c) are schematic representations of the punching process with a balancing body.

Ways to carry out the invention

In Fig. 1 is under Fig. 1 (a) schematically shown a punching device, wherein under FIGS. 1 (b) to (e) individual steps of a typical punching process are shown. Fig. 1 (f) finally shows a punched stack of benefits 4 'with unwanted overhang 8.

The output stack to be punched 1, 1 'come from a plan cutting device as a single or double stack to the punching device. The punching device for producing shaped labels comprises a lifting device 3, a hollow cylindrical punching knife 2 and optionally a counter-pressure element (not shown), which are arranged in a punching direction A successively along a punching conveyor 11. This allows a complete straightforward guidance up to a following Banding device (not shown). The lifting device 3 has a plane lifting plate 5, which serves to stack output stack 1, 1 'of sheet-like material in the punching direction A against the punching knife 2, wherein the benefit stacks 4, 4' are pressed by the hollow cylinder of the punching blade 2 ( Fig. 1 (b) to l (e)). The cut-off excess of the output stack 1, which is obtained outside the hollow cylinder and is led away as waste, is not shown. The punching direction A defines the punching conveying path 11 along which the output stacks 1, 1 'and the stamped benefit stacks 4, 4' are conveyed by the stroke of the lifting device 3.

It has now been shown that a stack of stacks 4 already stamped, which is still in the hollow cylindrical punching knife 2 (see Fig. L (c)), bulges down towards the lifting plate 5, as soon as the lifting plate 5 for the subsequent output stack 'has moved back. This bulge of benefit stack 4 is in Fig. 1 (d) shown.

Now, if a subsequent output stack 1 'pushed by means of the lifting device 3 against the punching knife 2, the uppermost layers of the sheet-shaped material of the subsequent output stack 1' due to the low force exerted by the bulge on the subsequent stack, curving. This ultimately leads to the punching knife attaching too far outside in the uppermost layers of the subsequent starting stack 1 'and the corresponding shape labels having an excess. The resulting benefit stack 4 'has, at least in the uppermost area, an overhang 8, as shown schematically in FIG Fig. 1 (f) is shown.

Fig. 2 shows a schematic side view of a lifting plate 5 with a compensation body. 6 Fig. 3 shows a schematic view of the surface of a lifting plate 5 with balancing body 6. The balancing body 6 is in the in Fig. 2 shown embodiment in the form of a leveling plate punched knife side placed on the flat lifting plate 5. The compensating body 6 forms within the sectional contour 9 (see. Fig. 3 ) of the punching knife from a survey which projects beyond the Hubplattenebene S. The thickness of the compensating body 6 can be 0.5 mm to 2 mm. In an approximately uniformly thick compensation body 6, this is preferably several Spaced millimeters from the cutting contour 9 inwardly offset and may have substantially the shape of the sectional contour 9.

With the sectional contour 9, the contour or contour is meant, which (r) by a projection of the cutting edge of the punching knife 2 perpendicular respectively. against the punching direction A results on the lifting plate 5. This sectional contour 9 also corresponds to the contact line of the punching blade 2 with the lifting plate 5, when the lifting plate 5 is guided to the punching knife 2. This contact line lies in the Hubplattenebene S. The cutting contour 9 also defines the outer contour of the form etiquette.

In Fig. 4 a compensation body 6 is shown, which is not formed uniformly thick, but is laterally flattened. In the case of such an embodiment of the compensating body 6, this can also extend almost to the cutting contour 9 and need not be spaced from this by several millimeters.

Another embodiment in Fig. 5 shown. In this case, the compensation body 6 is made in one piece with the lifting plate 5 and formed by a circumferential, milled into the lifting plate 5 groove 12 which projects beyond the cut contour 9 on both sides. The Hubplattenebene S is at the height of the groove 12th

Fig. 6 shows an embodiment in which the lifting plate 5 is provided with a support plate 13, for example made of plastic. The Hubplattenebene is defined by the support plate 13 and the compensation body 6 is placed on the support plate 13 or formed on this.

The FIGS. 7 (a) to (c) show a schematic representations of the punching process using a compensation body 6. At the end of a punching operation, the utility stack 4 is pressed centrally through the compensation body 6 relative to the edge region somewhat further in the punching direction, so that a lower region of the utility stack 4 is bent concavely inward (cf. , Fig. 7 (a) ). After the lifting plate 5 is retracted to receive the next output stack 1 ', the last punched stack of benefits 4 can relieve. However, experiments have shown that the utility stack 4 no longer bulges beyond the knife edge (cf. Fig. 7 (b) ) and so the subsequent output stack 1 'is pushed flat with the upper layers against the punching knife 2. In this case, a curvature of the upper layers is avoided and the resulting benefit stack 4 'has over the entire length of a consistent outer contour, so that no overhang forms.

name list

1, 1 '

output stack

2

punching knife

3

lifting device

4, 4 '

pile of sheets

5

lifting plate

6

compensation body

7

bulge

8th

overhang

9

sectional contour

10

survey

11

Punching conveying path

12

groove

13

platen

A

punching direction

S

Hubplattenebene

Claims (10)

Punching device for producing shaped labels from a starting stack (1, 1 ') of sheet-like material comprising: a hollow cylindrical punching knife (2) and a lifting device (3) with a lifting plate (5), around a stack of benefits resting on the lifting plate (4) 4 ') through the punching knife (2) by pushing the starting stack (1, 1') in a punching direction (A) against the punching knife (2); characterized in that the lifting plate (5) has a punching knife side a compensating body (6), wherein the compensating body (6) is designed such that within a cutting contour (9) of the punching blade (2) and circumferentially spaced from this a survey (10) results, which projects beyond a plane defined by the cutting contour (9) Hubplattenebene (S). Punching device according to claim 1, characterized in that the compensating body (6) is placed on a flat surface of the lifting plate (5) or integrated in this. Punching device according to claim 1, characterized in that the compensating body (6) and the lifting plate (5) are integrally formed. Punching device according to one of the preceding claims, characterized in that the compensating body (6) and / or the lifting plate (5) are exchangeably mounted in the lifting device (3). Punching device according to one of the preceding claims, characterized in that the compensating body (6) is designed in the form of a flat compensating plate. Punching device according to one of the preceding claims, characterized in that the compensation body (6) in the form of a bulge with flattened, in the Hubplattenebene (S) merging sides is formed. Punching device according to one of the preceding claims, characterized in that for the formation of the compensating body (6), the lifting plate (5) has a compensation body (6) encircling groove (12) which projects on both sides of the cutting contour (9). Punching device according to one of the preceding claims, characterized in that the lifting plate 5 comprises a support plate 13 on which the compensating body is arranged. Punching device according to one of the preceding claims, characterized in that an outer contour of the compensating body (6) relative to the sectional contour (9) is offset by at least 10 mm inwards. Punching device according to one of the preceding claims, characterized in that the compensation body (6) protrudes at its thickest point 0.5 mm to 2 mm, preferably about 1 mm above the Hubplattenebene (S).

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