EP2944440B1 - Stamping device and a stamping method for producing of form labels - Google Patents

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.

State of the art / 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 stack of benefits, ie the stack with the shape labels, is pressed by the punching knife and the cut-off supernatant is discharged outside the punching knife. 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. Depending on the starting material and / or the dimension of the utility stack, the problem may arise that the upper flat products of the stack bulge, which leads to inaccuracies in the shape of the labels and to an overhang of the utility stack as the punch knife penetrates into the starting stack ( Fig. 1 (a) and Fig. 1 (b) ).

In order to suppress the bulge for the most part and thus to increase the accuracy of the punching, was in EP0735938 proposed to press a punch on the opposite side of the lifting device to the stack Press to push the stack in a press-holding position by the punching knife. Even higher accuracies were achieved with a press die, which fits exactly into the hollow cylindrical punching knife and thus exerts a pressure on the entire surface of the stack of benefits. After punching the stack of benefits is pressed by the punch against the punching direction of the punching knife. A disadvantage of the counter-pressure method, however, is the lower throughput rate, because the benefit stack ejected each by means of the ram from the punching knife and seen in the punching direction 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.

If both punching methods are required in one operation, two different machines must be purchased. In principle, it would be conceivable to convert a machine with counter-pressure method. For this purpose, it would not be sufficient to remove only the counter-pressure device, but the supply to the banding would have either changed or continue the benefit stacks are offset laterally after the punching, which still leads to a loss of power.

Presentation of the invention

An object of the invention is to increase the throughput in the counterpressure process. Another object is to provide a punching device, which allows both punching process without cumbersome conversion.

The punching device according to the invention for producing shaped labels from a starting stack of sheet-like material and further conveying to a subsequent banding device along a punched conveying path comprises a hollow cylindrical punching knife, a lifting device, around a To push benefit pile through the punching knife by the output stack is pushed in a punching direction against the punching knife; and a counterpressure device for generating a counterpressure on the output stack in the direction of the lifting device in order to reduce buckling of the output stack when the punching knife penetrates into the starting stack. The counterpressure device has a counterpressure element which can be moved out of the punching conveying path and which is designed and controlled in such a way that it can be applied to an already stamped stack of use, so that the counterpressure can be transferred to a subsequent output stack to be punched by one or more already punched stack of benefits.

In this way, can be dispensed with a punch, which is moved into the punching knife by the already punched stack of benefits is used as a counter-pressure piston. The throughput rate can be increased compared to the method with ram, because the benefit stack each not ejected by means of the ram from the punching knife and seen in the punching direction must be led away laterally. An already punched stack of benefits is pushed out of the punching knife by the next output stack in the punching direction. A pressing out against the punching direction is not required.

Preferably, the output or punched stack of benefits from the lifting device to a subsequent Bandiervorrichtung are linearly movable on the punch conveying path.

In general, the counter-pressure device is designed such that the counter-pressure element is displaceable parallel to the punching direction and transversely to the punching direction or displaced.

The punching device can therefore also be used without the use of the counter-pressure device for conventional punch-through punching. It is sufficient, the counter-pressure element in a direction transverse to the punching direction pivoted pivoted or shifted position, which can be achieved umrüstfrei example by a simple control command.

The counter-pressure element can be designed in the form of a counter-pressure plate. Other forms that transfer the back pressure over a large area on the stack of benefits, such as gate or lattice-shaped or the like are also conceivable.

The counterpressure element can have an excess in relation to the maximum possible internal cross section of the hollow cylindrical punching blade in order to transfer the counterpressure over the full area to the stack of benefits. Preferably, the size of the counter-pressure element is chosen larger than the largest cross-sectional area of the punching knife, so that only the punching knife and not also the counter-pressure element has to be replaced. In this way, the changeover time when changing the punching knife can be significantly shortened.

The length of the punching knife may be shorter than the height of the starting stack. Initiation of the stamping process then requires only one output stack. The length of the punch blade may also be greater than the height of the output stack to allow for better guidance of the benefit stack. In this case, more than one output stack is needed for initiation. Ideally, the length of the punch blade is only a little shorter than an integer multiple (1x, 2x, etc.) of the height of an output stack, since the height of the output stack can be slightly reduced under pressure. In principle, however, the length of the punching knife can be arbitrary.

Furthermore, a conveying means may be present which, after removal of the counter-pressure element, is able to further convey the already punched use stacks, which are completely outside the punching blade, onto the punched conveying path. The conveying means may comprise a cutting knife directed transversely to the punching conveying path in order to transfer the separating knife to the cutting knife by means of transfer means to convey adjacent load stacks in direction course of the punching conveyor path.

The punching method according to the invention for producing shaped labels from a starting stack of sheet-like material, wherein an output stack is pushed in a punching direction against a hollow cylindrical punching knife, comprises the following steps: a) providing a starting stack to be punched in contact with a lifting device; b) applying a counter pressure to an already punched, at least partially protruding from the punch blade utility stack; and c) piercing the starting stack provided in step a) by the punching knife under the effect of the counterpressure on the starting stack to be punched over at least one already punched stack of benefits. In the stamping process, at least one already punched stack of use, which is still in the punching knife, used as a counter-pressure piston for the next output stack to be punched. The removal of the stack of benefits against the punching direction is unnecessary, which compared to the known counter-pressure method leads to increased throughput rates and simpler punching devices.

The steps a) to c) can be repeated for a predetermined number of punching operations before the counter-pressure element is removed transversely to the punching direction, so that the punched stack of benefits that are outside the punching knife, can be further promoted and processed in the same direction.

After the removal of the stack of benefits, the counter-pressure element can be applied again to the last stack of benefits still located at least partially in the punching knife in order to build up the counter-pressure for the next punching operation.

Brief explanation of the figures

Fig. 1

eine schematische Darstellung eines aufgewölbten Ausgangsstapels (Fig. 1(a)) und eines Nutzenstapels mit Überhang (Fig. 1(b)); und

Fig. 2

eine schematische Darstellung einer Stanzvorrichtung und der Schritte (Fig. 2(a) bis Fig. 2(h)) eines Stanzverfahrens.

The invention will be explained in more detail with reference to embodiments in conjunction with the drawings. Show it:

Fig. 1

a schematic representation of an arched output stack ( Fig. 1 (a) ) and a benefit stack with overhang ( Fig. 1 (b) ); and

Fig. 2

a schematic representation of a punching device and the steps ( 2 (a) to 2 (h) ) of a stamping process.

Ways to carry out the invention

In Fig. 1 (a) is schematically illustrated how bulges during punching without back pressure, an output stack 1 when penetrating in the punching direction A in the hollow cylindrical punching knife 2. This leads, as in Fig. 1 (b) shown schematically and exaggerated, to inaccuracies in the punching, which are reflected in an overhang in the benefits stack 4. The stamped labels thus have undesirably different sizes. The bulge and thus the inaccuracies of the shape labels is the greater the stronger the paper is structured and the more air is thereby trapped between the paper layers.

In Fig. 2 schematically a punching device with a counter-pressure element is shown, wherein under (a) to (h) individual steps of a punching process are shown.

The output stack to be punched come from a plan cutting device as a single or double stack to the punching device. The punching device for the production of shaped labels comprises a lifting device 3, a hollow cylindrical punching knife 2 and a counter-pressure element 5, which are arranged in a punching direction A successively along a punching conveyor 7. This allows a complete straight-line guidance up to the following banding device. The lifting device 3 serves to poke output stack 1 of sheet-like material in the punching direction A against the punching knife 2, wherein the benefit stacks 4 are pressed by the hollow cylinder of the punching blade 2 ( Fig. 2 (b) ). 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 a punching conveying path along which the output stack 1 and the punched-use stack 4, 4 ', 4 "are conveyed by the stroke of the lifting device.

On the opposite side of the lifting device 3 of the punching knife 2, a counter-pressure device 6 is arranged, which is parallel but driven from outside the punching conveyor 7. The counter-pressure device 6 comprises the counter-pressure element 5, for generating a counter-pressure P on the output stack 1 in the direction of lifting device 3 (ie counter to the punching direction A), to prevent buckling of the output stack 1 upon penetration of the punching knife 2 in the output stack 1 or at least reduce ( Fig. 2 (d) ). The counterpressure device 6 further permits pivoting in or out or insertion or ejection of the counterpressure element 5 into the punching conveying path of the punching device. Such a movement of the counter-pressure element 5 transversely to the punching direction A is for example in Fig. 2 (g) shown. The counter-pressure element 5 is in a position in which it does not cross the punch conveying path.

The counter-pressure element 5 is designed in this way and is controlled in such a way that it can be applied to an already punched-out benefit stack 4 (FIG. Fig. 2 (b) ), so that the back pressure P can be transferred via an already stacked stack of benefits to a subsequent output stack 2 to be punched ( Fig. 2 (c) ).

Fig. 2 (a) shows the punching device in an initial position for initiating the stamping process. A first output stack 1 is provided in abutment with the lifting device 3. The counter-pressure element 5 is in a free position within the punch conveying path.

Fig. 2 (b) shows a first punched stack of benefits 4, which was punched without counterpressure and later possibly discarded. This one serves also for the initiation of the stamping process. The stack of benefits 4 is completely or at least partially within the hollow cylindrical punching blade 2, depending on the length of the punching knife 2. If the punching knife 2 is longer than an output stack 1, then a second punching without back pressure takes place before the initiation is completed.

Fig. 2 (c) shows a first step of the stamping process after initiation. In this case, the counter-pressure element 5 is in contact with a punched stack of benefits 4 and at least one further output stack 1 'is provided in abutment with the lifting device 3. The counter-pressure element does not cause any back pressure P on the stack of benefits. 4

In Fig. 2 (d) is the lifting device 3 as far moved in the punching direction A, that a following output stack 1 'is applied to the punching knife 2. Thereafter, a back pressure P on the first, at least teilwesie from the punch blade 2 projecting stack of benefits 4 is constructed by the counter-pressure element 5.

In Fig. 2 (e) is another output stack 1 'pushed by the punching knife 2 to produce a further benefit stack 4'. The back pressure P is kept as constant as possible and transmitted via the or the already punched stack of benefits 4 to the subsequent output stack 1 'in order to prevent bulging.

In Fig. 2 (f) is provided a further output stack 1 "Before the return of the lifting device 3, the back pressure P is lifted to the benefit stack 4 ', so that it is not pushed back.

In Fig. 2 (g) a subsequent output stack 1 "has been pushed by counterpressure P through the punching knife 2 and has been punched to a further use stack 4". The back pressure P is transferred to the output stack via several benefit stacks.

After a certain number of punching operations, the counterpressure device 6 can move the counterpressure element 5 laterally out of the punched conveying path ( Fig. 2 (h) ). The benefit stacks 4, 4 ', which are located outside of the punching knife 2, are removed, separated to the subsequent banding device, there again to individual benefit stacks and provided with a band. The counter-pressure element 5 is again in the position Fig. 2 (c) driven and on the last still located in the punching knife utility stack 4 "set to build the back pressure P for the next punching operation.

In principle, the length of the punching knife 2 can be arbitrary. However, an improved guidance results if the punching knife 2 is longer than a punched stack of benefits 4, 4 ', 4 ". On the other hand, if the punching knife is shorter than a stack of benefits 4, 4', 4", the initiation time is shorter. Not mandatory for the stamping method of interest here, but usual in practice, the lowest layer, uppermost layer or both layers of each output stack 1, 1 ', 1 "is covered with a cardboard layer, which facilitates later separation of the benefit stacks 4, 4'. 4 "after punching and protects the shape labels during banding. The cardboard layer also forms an optical marking, which can be optically detected in the feed control and the exact introduction of a separating knife between two benefit stacks 4, 4 ', 4 "allowed.

name list

1, 1 ', 1 "

output stack

2

punching knife

3

lifting device

4, 4 ', 4 "

pile of sheets

5

Counterpressure element

6

Counter-pressure device

7

Punching conveying path

A

punching direction

P

backpressure

Claims (11)

1. Punching device for producing shaped labels from an initial stack (1, 1', 1") made of sheet-type material and conveying further to a subsequent taping device along a punching-conveying path, comprising:

   a hollow cylindrical punching blade (2);

   a lifting device (3) in order to press a usable stack (4) through the punching blade (2), by the initial stack (1) being pushed in a punching direction (A) against the punching blade (2); and

   a counter-pressure device (6) for producing a counter-pressure (P) on the initial stack (1, 1', 1") in the direction of the lifting device (3) in order to reduce bulging of the initial stack (1, 1', 1") when the punching blade (2) is forced into the initial stack (1) ;

   characterised in that

   the counter-pressure device (6) comprises a counter-pressure element (5) which is able to be moved out of the punching-conveying path and which is configured and controlled such that it is able to be applied to an already punched usable stack (4, 4', 4") so that the counter-pressure (P) is able to be transmitted through one or more already punched usable stacks (4, 4', 4") onto a subsequent initial stack (1, 1', 1") to be punched.
2. Punching device according to Claim 1, characterised in that the initial stacks (1, 1', 1") and/or punched usable stacks (4, 4', 4") are able to be moved by the lifting device (3) to a subsequent taping device in a linear manner on the punching-conveying path (7).
3. Punching device according to one of the preceding claims, characterised in that the counter-pressure element (5) is able to be displaced parallel to the punching direction (A).
4. Punching device according to one of the preceding claims, characterised in that the counter-pressure element (5) is configured in the form of a counter-pressure plate.
5. Punching device according to one of the preceding claims, characterised in that the counter-pressure element (5) has an excess length relative to the maximum possible internal cross section of the hollow-cylindrical punching blade (2).
6. Punching device according to one of the preceding claims, characterised in that the length of the punching blade (2) is shorter or longer than the height of the initial stack (1, 1', 1").
7. Punching device according to one of the preceding claims, characterised in that a conveying means is present, said conveying means enabling the already punched usable stacks (4, 4', 4"), which are located entirely outside the punching blade (2), to be conveyed further on the punching-conveying path (7) after the counter-pressure element (5) is removed.
8. Punching device according to one of the preceding claims, characterised in that the conveying means comprises a separating blade oriented transversely to the punching-conveying path (7) and by means of transfer means is able to convey further the separating blade with the adjacent usable stack (4, 4', 4") in the directional path of the punching-conveying path.
9. Punching method for producing shaped labels from an initial stack (1) made of sheet-type material, wherein the initial stack (1) is pushed in a punching direction (A) against a hollow-cylindrical punching blade (2), comprising the following steps:

   a) providing an initial stack (1', 1") to be punched in abutment against a lifting device (3);

   b) applying a counter-pressure (P) to an already punched usable stack (4, 4', 4") protruding at least partially from the punching blade (2);

   c) pushing the initial stack (1', 1") provided in step a) through the punching blade (2), by the action of the counter-pressure (P) on the initial stack (1', 1") to be punched, via the already punched usable stack (4, 4', 4").
10. Punching method according to Claim 6, characterised in that steps a) to c) are repeated for a predetermined number of punching processes before the counter-pressure element (5) is removed transversely to the punching direction (A) so that the punched usable stacks (4, 4'), which are located outside the punching blade, may be removed and processed further.
11. Punching method according to Claim 7, characterised in that after removing the punched usable stacks (4, 4') the counter-pressure element (5) is applied to the usable stack (4") located in the punching blade (2) in order to create the counter-pressure (P) for the next punching process.

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