WO1995001245A1

WO1995001245A1 - Transverse cutting process for material webs and device therefor

Info

Publication number: WO1995001245A1
Application number: PCT/CH1994/000137
Authority: WO
Inventors: Gusti Ochsner
Original assignee: Ochsner + Co., Inh. G. Ochsner
Priority date: 1993-07-01
Filing date: 1994-07-01
Publication date: 1995-01-12
Also published as: CH688228A5

Abstract

In order to cut material webs conveyed on a substrate, preferably paper or plastic webs, transversely, preferably two rotary rollers (5, 6) arranged above the material web (2) are each fitted with an upper blade (5', 6') which cut through the material web (2) at an adjustable time depending on the conveying speed. According to the invention, behind the second blade roller (5) the sections of material web cut off by the blade roller (5) are alternately removed in two different directions. The process is thus especially suitable for cutting printed material webs in which there are unprinted sections between the printed regions which have to be removed.

Description

Process for cross cutting material webs and device therefor

The present invention relates to a method for cross-cutting a material web conveyed over a support, in particular a paper or plastic strip, which is passed under at least one knife roller, the knife roller at an adjustable point in time depending on the conveying speed of the material web cuts through, and immediately after the knife roller by means of a deflection flap the incoming end of the material web can be directed away from the original web direction and a device for this.

In order to cut material webs conveyed on systems, a knife arranged on a rotatable roller is conventionally used, which together with a counter knife arranged below the material web cuts the material web each time the knife roller has been handled.

Such devices are used, for example, in the paper processing industry in that long paper strips arranged on rolls are cut into individual sheets.

The problem now arises, in particular, in the case of printed paper tapes that they have to be cut into individual sheets to a certain size, the cut edges having to lie at certain positions on the printed paper tape. If the paper tapes are now printed using printing rollers, another problem arises It is a problem that the printed areas do not follow one another directly, since the circumference of the printing roller specifies a fixed, predetermined length of the printing area, but the actual printed area is generally smaller. For the cutting of such printed paper webs, this now means that not only does one cut have to be carried out at regular intervals, but a second cut is also necessary in order to cut away the unprinted area.

To solve this problem, it is proposed in US Pat. No. 4,784,318 to use a single rotatable roller provided with a knife, called a knife roller for short, which in each case activates a cross-section through the belt, for example a paper belt becomes. The activation takes place by means of a control device in which codes applied to the tape and which are detected by optical means are processed. The codes can be printed on the tape in the form of so-called bar codes. Immediately after this knife roller, a mechanical deflection device in the form of a flap is provided, which can be pivoted into the material web in an electromagnetically controlled manner and thus can deflect parts of the band away from the material web. In particular, residual parts are thus guided away from the material web downwards into a container. This device is particularly suitable for transversely cutting consecutive band parts of different lengths, which may be separated from one another by a separating area. However, the device proposed in the document only allows a relatively low belt throughput to be achieved, and the parts to be removed from the material web must have a certain length. On the one hand, this stems from the use of a single knife roller, which always has to make a complete revolution for successive cuts, during which time the belt is transported further. On the other hand, the electromechanical control of the flap by means of an electromagnet leads to relatively low swiveling speeds of the flap.

Furthermore, such methods and devices with several knife rollers are known (US 4,480,516; US 5,199,341), in which strip parts are led out of the material web by means of negative pressure. However, these methods and devices also have the disadvantage that only a comparatively low belt speed can be achieved, so that such belt parts can be guided away due to the inertia of the air flow when under or. Overpressure.

The object of the present invention was now to provide a method in which the disadvantages described are eliminated, i.e. that even very small strip parts can be reliably removed from the material web, and nevertheless a high material web speed can be achieved.

This object is achieved according to the invention in that the deflection flap is actuated by the knife roller in such a way that it is immediately in front of. during a cutting operation of the knife roller, the material web is swung away so that the front cutting edge of the following material strip is conveyed further over the deflection flap in the original direction of the material web, and that the deflection flap is subsequently swung back into the material web, so that in each case one mate alternates ¬ radial strips in the original web direction promotes and the following is led away from the web direction.

Preferred embodiments of the invention result from claims 2 to 5.

A very rapid movement of the deflection flap is achieved by the inventive control of the deflection flap by the knife roller. This means that even at high conveying speeds of the material web, even very small material strips can be captured by the deflection flap and can be reliably guided away from the original direction. The control disk of the knife roller controls the swiveling out of the flap out of the material web, which has to be done extremely quickly with small strips of material. The flap can preferably be reset by means of compressed air; there is much more time for this movement. The large swivel range of the deflection flap into the material web makes it possible to reliably remove even slightly corrugated material strips from the material web. The "soft", not scalloped-like movement of the deflection flap advantageously leads to reduced noise and less wear.

The material web pieces continued in the original web direction can, for example, be continuously further processed in further downstream processing devices. For example, such pieces can be cut on the longitudinal edges and then folded and packaged. This is particularly suitable for processing brochure material printed on paper. A device according to the invention for carrying out the method is described in claims 6 to 10.

An embodiment of the invention is explained in more detail below with reference to drawings. Show it

1 shows the schematic cross section of a cross cutting device according to the invention;

FIG. 2 shows a detail of the area of the deflection device from FIG. 1 in the starting position;

3 shows the view of FIG. 2 shortly after the section of the second roller;

4 shows the view from FIG. 2 when the first roller is cut; and

Fig. 5 shows the view of the second knife roller in the position of Figure 3 with a schematically shown control disc connection.

1 schematically shows a cross-cutting device according to the invention, in which a material strip 2, for example a paper strip, which is unwound from a roll, for example, by means of conveyor rolls 3 under two knife rolls 4 and 5 arranged one after the other is pushed through. On the circumference of the knife rollers 4, 5, an upper knife 4 *, respectively, oriented transversely to the transport direction of the belt 2, 5 'arranged. Each knife roller is 4.5 ^', a material strip fest¬ stationary lower knife ^4, 5' allocated below the '. When the knife rollers 4, 5 rotate, the material strip 2 is cut transversely at this point each time the upper knife 4 ', 5' passes through the corresponding lower knife 4 ^{, I} , 5 ¹ '.

Further conveyor rollers 6, which additionally drive the material belt, are advantageously arranged between the two knife rollers 4, 5.

The transport rollers 3 are driven, for example, via a motor box 7, which drives the two knife rollers 4, 5 via a differential gear 8 in an adjustable transmission ratio. The transmission ratio is adjusted in such a way that the material web 2 is regularly cut through the knife rollers 4, 5 at a predetermined point. By means of the differential gear 8, the relative angular position of the two upper knives 4 'and 5' relative to one another can be adjusted continuously, preferably also during the operation of the device. In this way, two sections of material web 2 of different or equal length can alternately be produced, which can subsequently be transported on or collected.

Separate electric motors can also be used as drives for the individual transport rollers and knife rollers, which are operated by means of electronic control or regulation in the manner described.

It is also conceivable that one of the two knife rollers is shut down for the production of simple sections from band 2, or that additional knife rollers are arranged if more than two different, successive cutting formats are required. According to the cross cutting device 1 has a deflection flap 9, which immediately after resp. in the second knife roller 5, for example, is arranged below the material web 2. This deflection flap 9 is used to alternately lead or cut a section of the material web 2 from the original web direction. to remain in the original web direction. The mode of operation of the deflection flap is explained in more detail below with reference to FIGS. 2 to 4.

FIG. 2 shows the deflection area of the cross-cutting device 1, wherein a deflection flap 9 that can be pivoted about an axis 10 is provided, which preferably extends over the entire width of the knife roller 5. Before the upper knife 5 'strokes the lower knife 5 ¹ ', the free end of the deflection flap 9 is pivoted upward and in doing so leads the beginning of the material web 2 downward from the original web direction, for example into a collecting container (not shown).

If the upper knife 5 'now sweeps over the lower knife 5' ', as shown in FIG. 3, and thereby cuts through the material web 2 transversely, the deflection flap 9 is pivoted downward. According to the invention, this movement takes place by means of a direct cam control which connects the deflection flap 9 to the knife roller 5. The section 2 ′ of the material web 2 that has now been cut completely falls downward, while the subsequent new end of the material web 2 slides over the free end of the deflection flap 9.

The deflection flap 9 is then pivoted upward again, as shown in FIG. 4. The material web 2 continues to pass over the free end of the deflection flap 9 headed. In the meantime, the material web 2 is also cut through by the knife roller 1. The new cut edge of the following material band section is now guided downward again through the free end of the deflection flap 9, as already shown in FIG.

The additional conveyor rollers 6 are preferably operated in such a way that they have a slightly higher speed than the conveyor rollers 3. In this way, the very small cutting width produced by the knife roller 4 in the material belt 2 is additionally widened, which increases the reliability of the deflection described.

By choosing the relative angular pitch of the two upper knives 4 'and 5 ¹ with one another, the ratio of the alternating successive two material band sections can be adjusted continuously, while the transmission ratio between the conveyor rollers 3 and the knife rollers 4, 5 is the absolute length of two successive of the material strip sections determined.

Preferably, instead of mechanical transmission transmission systems, an electronically controlled or regulated transmission of the drives of the conveyor rollers and knife rollers can be provided. For this purpose, additional measuring elements, for example for the effective material web speed after the conveyor rollers 3, are provided, on the basis of whose signals the rotational speed and, if appropriate, positioning of the knife rollers are controlled or. can be regulated. This enables consistently precisely positioned cuts to be achieved.

FIG. 5 schematically shows an embodiment variant of the cam drive according to the invention. On one A control disk 11 is attached to the end of the knife roller 5. This actuates the deflection flap 9 via a push rod 12, which is guided in correspondingly designed bearings 13. The push rod 12 preferably has a cam roller 14 for connection to the cam disk 11. Either a spring element can be provided to press the cam roller 14 onto the control disk 11, or an air pressure element can also be provided, for example. Of course, it is also conceivable to provide a different, conventional cam transmission. In particular, the control disk 11 can be arranged such that it actuates the deflection flap 9 directly (without a push rod 12). It is also conceivable that the control disk 11 is not arranged directly on the axis of the knife roller 5, but only via a gearbox or. is connected to the knife roller with a toothed belt or the like.

Such a cross-cutting device is particularly suitable for trimming printed paper rolls in which unprinted areas are to be cut away between the actual printing areas and the printed, cut sections are to be processed further, for example to be folded or packaged.

Claims

claims

1. A method for cross-cutting a material web conveyed over a support, in particular a paper or plastic strip (2), which is passed under at least one knife roller (5; 4), the knife roller (5; 4) in each case adjustable time depending on the conveying speed of the material web (2) cuts it across, and immediately after

Knife roller (5) by means of a deflection flap (9) the incoming end of the material web can be guided away from the original web direction, characterized in that the deflection flap (9) is actuated by the knife roller (5) in such a way that it . during a cutting process of the knife roller (5) is pivoted away from the material web (2), so that the front cutting edge of the following material strip is conveyed further via the deflection flap (9) in the original direction of the material web, and that the deflection flap (9) subsequently returns to the Material web (2) is swung in, so that in each case an alternating material strip is conveyed further in the original web direction and the following is guided away from the web direction.

2. The method according to claim 1, characterized in that the deflection flap (9) is pivoted out of the material web (2) immediately before the engagement of the upper knife (5 ¹ ) and at least a quarter turn of the knife roller (5) later in the Material web (2) is swung in.

3. The method according to claim 1 or 2, characterized gekenn¬ characterized in that the front edge of the deflection flap (9) at least at least 5 mm, preferably more than 7 mm, is swung into the material web (2).

4. The method according to any one of claims 1 to 3, characterized in that the pivoting movement of the Umlenkklap¬ pe (9) does not occur suddenly, but with increasing speed.

5. The method according to any one of claims 1 to 4, characterized in that two knife rollers (4,5) are provided, under which the material web (2) is passed, and that the rotational speeds of the knife rollers (4,5) in one certain ratio to the conveyor speed of the material web (2) can be set and this setting is kept constant by means of a control or regulation.

6. Device for performing the method according to one of claims 1 to 5 with a device for the promotion of material webs, in particular paper or plastic webs (2), with a first knife roller (4) with an upper knife (4 ') and at least a second knife roller (5) with an upper knife (5 ') which rotates over the

Material web (2) are arranged, and which each have associated lower knives (4 ^{, I} , 5 '') arranged under the material web (2), and a deflection flap (9) arranged after the second knife roller (5), characterized in that that the deflection flap (9) by means of a control disc (11) on the corresponding knife roller

(5) can be actuated in such a way that it enters the material web before or immediately after the upper knife (5 ')

(2) engages, is pivoted away from the material web (2) and, after the knife (5 ') engages, is pivoted back into the material web (2).

7. The device according to claim 6, characterized in that the deflection flap (9) is arranged under the material web (2) and can be pivoted toward the top into the material web (2).

8. The device according to claim 6 or 7, characterized gekenn¬ characterized in that the deflection flap (9) is pressed by means of air pressure against the pressure of the control disc (11).

9. Device according to one of claims 6 to 8, characterized in that the deflection flap (9) at least 5mm, preferably 7mm, can be swung into the material web (2) into it.

10. The device according to one of claims 6 to 9, characterized _in that the control disc (11) is shaped such that the pivoting-out of the diverter (9) takes place with increasing speed.