EP0242320B1 - Method and device for punch-cutting readily processable stacks interspersed among one another on strip material - Google Patents

Description

The invention relates to a method for separating single-use stacks arranged on pre-cut useful-strip stacks, for example printed bottle neck labels, with a punching iron having a punching contour, which can be moved against a punching table, the rear contour of the separated single-use stack corresponding to the front contour of the next single-use stack.

Today's printed products, such as labels and similar products, are printed on a sheet and processed in car boards. The connection of the punching lines creates punching bridges that have to be removed before further processing; this is time consuming and expensive. From DE-AS 1 226 025 it is known to punch in small layers with an attachment iron, but there is a displacement in the paper stack which is greater the higher the stack. Punching machines have therefore been developed for high-quality products and long runs, which avoid these punching bridges and make do with small tolerances.

As is known from DE-OS 2 225 586, blanks for these punching machines are placed on top of one another in layers of 500-1250 sheets, depending on the production, and pre-cut rectangularly on sheet cutters to produce stacked strips.

Each panel stack contains a large number of individual panel stacks that have to be separated with a cutting machine in a pull cut. A punching machine is arranged downstream of this strip cutter, in which the individual blanks receive their final outer contours. A nesting of the individual benefits, as would be aimed at to save paper, is not possible with high stacks, since these can only be processed with an oscillating cut and this only allows straight cuts. The rectangular preliminary products produced in this way mean a high loss in the case of contours with large contours, since paper and printing account for approximately 70 to 80% of the production costs.

The object of the invention is to provide a method for punching pre-cut strips of useful strips with individual grooves with strong contours, in which the waste produced by pre-production can be reduced to a minimum.

This object is achieved in that the individual blanks are arranged in an interleaved manner on the stack of blanks and separated with a punch cut running perpendicular to them with an open, non-linear, freely selectable punch line.

With these measures, individual contours with strong contours can be moved closely together on a sheet and separated with a punch. The paper waste is reduced to a minimum, which in turn means a large amount of paper spam. Two or three punching units can also be coupled in series, since the front cut in the first unit and the single cut in the second unit can be carried out.

The invention further relates to a device for separating single-use stacks arranged nested on pre-cut useful-strip stacks, for example printed bottle neck labels, with a punching iron having a punching contour, which can be moved against a punching table, the single-use stack in the area of the intended cutting line with a press bar along one Pressure contour are held, especially for performing a method described above.

The individual-use stacks are held down in the area of the intended cutting line with a pressure beam along a pressure contour. The cutting line runs at a different distance from the contact contour, so that there can be differences in the held-down stack and warping of the individual benefits. From DE-PS 685 530 it is known to break down the press beam into individual sections. This breakdown enables the press beam to be adjusted to different thicknesses and to exert a constant contact pressure. However, such a pressure beam cannot be adapted to a cutting line that is far from the contact contour and that is said to be extremely accurate.

A further object of the invention is to provide a device for the dimensionally accurate separation of individual-use stacks arranged nested on a stack of utility strips along variable cutting lines.

This object is achieved in that the pressure contour of the pressure beam can be varied by means of exchangeable, displaceable holding means.

• Fig. 1 die schematische Darstellung eines vorgeschnittenen Streifens mit herkömmlich angeordneten Einzelnutzen für rechteckige Vorprodukte;
• Fig. 2 die schematische Darstellung eines vorgeschnittenen Nutzenstreifens mit verschachtelten Einzelnutzen zum Schneidstanzen mit freier Schneidlinie;
• Fig. 3 die schematische Darstellung des Streifenstanzens mit freier Schneidlinie zur Verarbeitung von Nutzenstreifen nach der Fig. 2;
• Fig. 4 die Draufsicht auf einen Nutzenstreifen, der auf dem Stanztisch einer Schneidstanze unter einem, mit einer Matritze versehenen Preßbalken gehalten ist und von dem ein Nutzenstapel mit einem Stanzeisen abgetrennt wird;
• Fig. 5 die Seitenansicht der Schneidstanze nach Fig. 4;
• Fig. 6 die Draufsicht auf eine Schneidstanze nach Fig. 4 mit Preßbalken mit verschiebbaren Einschubstücken.

Further advantageous measures are described in the subclaims. The invention is illustrated with an embodiment in the accompanying drawing and will be described in more detail below; it shows:

• Figure 1 is a schematic representation of a pre-cut strip with conventionally arranged individual benefits for rectangular primary products.
• Figure 2 is a schematic representation of a pre-cut strip with nested individual blanks for punching with a free cutting line.
• 3 shows the schematic representation of strip punching with a free cutting line for processing utility strips according to FIG. 2;
• 4 shows the top view of a blank strip which is held on the punching table of a cutting punch under a press beam provided with a die and from which a stack of panels is separated with a punching iron;
• 5 shows the side view of the cutting punch according to FIG. 4;
• Fig. 6 is a plan view of a cutting punch according to Fig. 4 with a press beam with displaceable push-in pieces.

The utility strips 18 shown in FIGS. 1 and 2 consist of a large number of individual panels 36. The side edges 32 of the utility strips 18 run straight and parallel to one another. On the benefit strip 18 shown in FIG. 1, the individual benefits 36 are arranged so far apart from one another in the usual way that they can be separated along a straight cut line 40. In this way, rectangular preliminary products are produced, from which the individual blanks 36 are punched out with a subsequent punching machine, not shown.

The train section line 40 runs between the front contour 34 of the subsequent panel 41 and the rear contour 33 of the front panel 42 - with reference to the conveying direction 27 (arrow). The panels 41 and 42 have such a large panel spacing 37 that a free pull cut is possible. The useful spacing 37 depends on the contour depth 38 and the edge spacing 44 between the front contour 34 and the drawing line 40. Since this useful spacing 37 can be very large, the waste surface 43 that cannot be used can also be very large.

On the utility strip 18 shown in FIG. 2, the individual panels 36 are arranged in an interleaved manner and moved together to such a small panel spacing 37 as corresponds to the distance of the front panel 42 from the cutting edge 31 and from the cutting edge 26 to the subsequent panel 41. The waste area 43 is thereby reduced, so that a larger number of benefits can be accommodated on the same strip area. The panels interleaved in this way are separated from the panel 18 along a contour cutting line 16.

As shown in FIG. 3, a punching iron 13 is used to separate such a stack of panels 19 from the panel 18 to be punched, the punching contour 39 of which corresponds to the cutting line 16 between the individual panels 36. For this purpose, the useful strip 18 is pushed under the punching iron 13 with a conveyor slide 45. The cutting line 16 of the punching iron 13 is open and freely selectable and at least partially follows the rear contour 33 of the separated stack of panels 19. The separated stack of panels 19 absorbs the displacement generated by the punching iron 13 in the form of an offset angle 35, around which it extends in the working direction 27 (arrow ) is moved. This offset angle 35 runs continuously over the entire stack height 46, so that individual benefits 36 which are offset in the stack but are true to size are produced. The punching iron 13 has a straight trailing edge, which causes a smooth cutting edge 31 on the remaining utility strip 18, permits subsequent erection, with which the utility stacks 19 are aligned prior to further processing and the individual benefits 40 are placed exactly one above the other again. The stack heights 46 to be punched can thus be selected to be substantially larger.

The benefit strips 18 to be punched should be held as close as possible to the cutting line 16 in order to avoid throwing up the individual benefits 36. A cutting punch 10 is shown in FIGS. 4 to 6, in which a press bar 11 presses the inserted utility strip 18 onto a punching table 17. As FIG. 4 shows, the individual stack of panels 19 can be separated from the panel of strips 18 with a punch 13 along the cutting line 16. The press beam 11 is guided in a press beam guide 12 and the punch 13 in a punch guide 14. In the exemplary embodiment shown, these guides 12 and 14 run vertically and one behind the other, but a common guide or an arrangement laterally next to one another is also possible.

As shown in FIG. 5, a die 20 is inserted into the press beam 11, the front edge 25 of which extends in the working direction 27 (arrow) into the area of the cutting edge 15 of the punching iron 13. The die 20 is provided with one or more holders 21 and fastened to the press beam 11 with fastenings 22. In this exemplary embodiment, the punching iron 13 has a hollow cylindrical inner contour 26 which at least partially surrounds the die 20. For this purpose, the cutting edge 15 is provided with a cutting edge angle 29, which displaces the separated stack of benefits 19 in the working direction 27. To increase the strength of the punch iron 13, the cutting angle 29 is chamfered.

In the embodiment shown in FIG. 6, the press beam 11 is provided with a plurality of insertion pieces 23 which can be displaced relative to it. These insertion pieces are provided with holders 21 and fastenings 22, with which they can be releasably fixed to the press beam 11 in different positions, in order to also achieve very strongly varying cutting lines 16a with a contact contour 24.

The front edges 25 of the matrices 20 and insertion pieces 23 can deviate from the alignment of the lower edge 30 of the press beam 11 with the same or different angles of attack 28. This creates a pretension with which the moment of the holding means 20 or 23 is compensated with respect to the pressure beam guide 12.

By different angles of attack 28 of the individual insertion pieces 23, different prestresses can be achieved within a contact contour 24, with which, for example, tolerance fluctuations can be compensated for, which arise due to differences in the material height and structure, through different color applications, embossing, material compositions and the like.

Claims (4)

1. A method for separating individual item stacks (19) arranged on precut item strip stacks (18), for example printed bottleneck labels, with a punching iron (13) which has a punching contour and which is movable towards a punching table, the rear contour of the separated individual item stack corresponding to the front contour of the next-following individual copy stack, characterised in that the individual item (36) are arranged internested on the item strip stacks (18) and are separated with a punching cut extending perpendicular to them and having an open, nonrectilinear, freely selectable, punching line (16).

2. Apparatus for separating individual item stacks (19) arranged internested on precut item strip stacks (18), for example printed bottleneck labels, with a punching iron (13) which has a punching contour (39) and which is movable towards a punching table (17), the individual item stacks (19) being held in the region of the intended cutting line (16) with a presser bar (11) along a pressing contour (24), more especially for carrying out a method according to claim 1, characterised in that the pressing contour (24) of the presser bar (11) is variable by means of exchangeable displaceable retaining means (20, 23).

3. Apparatus according to claim 2, characterised in that matrices (20) or individual insert pieces (23) having the pressing contour (24) are inserted as retaining means, following the cutting line (16, 16a) between the individual item stacks (19), into the presser bar (11).

4. A cutting punch according to claims 2 or 3, characterised in that the front edge (25) of the retaining means (20, 23) is biassed by angles of incidence (28) relative to the presser bar (11), the angles of incidence (28) of the retaining means (20, 23) being individually variable.

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