DE29700519U1 - Device for cross-cutting a strand-like structure - Google Patents

Description

The invention relates to a device of the type corresponding to the preamble of claim 1.

The technique of working with a punching knife against a non-hard cutting base is known in many areas, for example where such a punching knife is used to punch out shaped pieces from a web-like material or larger surface structure. The punching knife penetrates through the material and a little into the non-hard cutting base, resulting in a complete and burr-free separation of the shaped piece.

If a large number of identical cuts are made at the same point on the cutting base using such an arrangement, the base will wear out and the cleanliness of the cut will suffer greatly. This is the case, for example, if certain sections of a strand always have to be cut off at the same point.

An example of such a case is a cigarette paper book manufacturing machine, in which a strand

D-40239 DÜSSELDORF MULVANYSTRASSE 2 TELEPHONE 49 / 211 / 96 145 - 0 FAX 49/211/96 145 - 20

D-45133 ESSEN FRÜHLINGSTRASSE 43 A TELEPHONE 49/201/84 230 - 0 FAX 49 /201 / 84 230 - 20

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is formed from alternating folded paper strips, from which packets of cigarette length are to be cut off in a cutting station, which are then provided with a small outer packaging and form a so-called cigarette paper book from which individual cigarette paper leaves can be removed as required.

A cigarette paper booklet contains, for example, fifty or one hundred cigarette paper sheets for rolling cigarettes. The cigarette paper sheets are elongated rectangular in shape to match the cigarette and folded into a V shape around their longitudinal center line. Neighboring cigarette paper sheets are inserted into one another with their open sides, so that the folded edges of successive cigarette paper sheets in a packet lie alternately on one and the other long side of the packet.

A cigarette paper book manufacturing machine is known from DE-OS 42 01 256. Paper strips are unwound from the paper rolls, the number of which corresponds to the number of cigarette paper sheets contained in the book, folded around their longitudinal center line, alternately joined together and pressed together to form a flat strand, from which the individual packets are cut in cigarette length in a cross-cutting device, which are then provided with the outer packaging.

The invention is based on the object of avoiding the problems associated with the wear of the cutting base in a cross-cutting device of this type.

This object is solved by the invention set out in claim 1.

The belt forming the cutting base moves a short distance in its longitudinal direction after each cut or after a few cuts at most, so that the punching knife hits a new, unstressed part of the belt during the next cut and the cut can therefore always be carried out optimally. The support roller is used to carry the belt and

experiences a uniform stress over the circumference due to the constant movement.

According to claim 2, the belt can be guided approximately meander-shaped over the support roller, which promotes good traction of the belt without slippage due to the large wrap angle.

This aim is also served by the feature of claim 3, according to which the support roller is roughened on its circumference.

The term "roughening" should also be understood to include measures such as knurling or corrugation.

The support roller should be driven in rotation depending on the strokes of the punching knife (claim 4) and in particular in the intermittent manner specified in claim 5. After each stroke of the punching knife or after a few strokes of the same, the belt should be rotated further by a small amount so that the next stroke of the knife hits a new point on the belt.

In practice, further turning steps have proven to be

0 have proven useful, which result in a displacement of the band by about 0.15 to 0.25 mm (claim 6).

In the preferred embodiment according to claim 7 the band consists of plastic, for example polyethylene.

5 The drawing shows an embodiment of the invention in a cigarette paper book manufacturing machine.

Fig. 1 shows an overall perspective view of a cigarette paper book manufacturing machine;

Fig. 2 shows the principle of the mutual interlocking of the longitudinally folded paper strips;

Fig. 3 shows a perspective view of a finished cigarette paper booklet;

Fig. 4 shows a perspective view of the
cutting station;

Fig. 5 shows an enlarged perspective view of the area of the punching knife and the support roller;

Fig. 6 shows a side view of the cutting station, in which the course of the belt is indicated.

The cigarette paper book manufacturing machine designated as a whole with 100 in Fig. 1 comprises a bank 10, i.e. a substantially straight, elongated frame on which a number of paper rolls 1 corresponding to the number of cigarette paper sheets in a book are mounted so as to be rotatable about axes parallel to the longitudinal direction of the bank 10. The paper rolls 1 each consist of a paper strip 2 with a width corresponding to the width of the cigarette paper sheet. The paper rolls 1 are arranged on the bank 10 on suitable bearing stands on two axes which are horizontally arranged next to one another at a short distance. The first, third, fifth, etc. paper roll 1' runs on an axis which is on the left-hand side according to Fig. 1, the second, fourth, sixth, etc. paper roll 1'.' on an axis which is offset slightly to the right. The reason for this is that successive cigarette paper sheets are joined together in an inverted arrangement (Fig. 2) and the folding therefore also takes place in the opposite direction, which makes the staggered arrangement necessary for structural reasons.

The bank 10 carries, in addition to the paper rolls 1, the

Strand formation stations belonging to each paper roll 1, designated as a whole with 20, for longitudinally folding, deflecting and joining the longitudinally folded paper strips 2 into a strand 30 running horizontally along the bank 10.

For each individual paper roll 1, the strand forming station 20 is preceded by a deflection roller 3 adjacent to it, located at the height of its upper area, over which the paper strip 2 is guided from the underside of the associated paper roll 1 and from which the paper strip 2 runs downwards. It then passes a stripper 4, which improves the precise running of the paper strip 2 while maintaining a predetermined lateral position, and then reaches a folding unit designated as a whole by 5.

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device in which the paper strip 2 running vertically after the stripper 4 is first curved and then folded by 90° while being deflected, whereupon it is laterally inserted into the uppermost layer of the already formed strand of paper strips in a manner to be explained with reference to Fig. 2.

The finished strand 30, which represents the structure to be cut crosswise, in which all fifty or one hundred lengthwise folded paper strips 2 are combined and which has a flat rectangular cross-section with horizontal flat sides, runs horizontally according to Fig. 1 and is pulled out of the bank 10 from right to left according to Fig. 1 by a double belt 7,7 arranged in the drive station 6, which is continuously driven at a constant speed and which rests on the two flat sides of the strand 30, and is continuously fed via a buffer station 8 to the cutting station 9, in which, while the strand 30 is standing, sections corresponding to the length of a cigarette are cut off, which form packets 11 of cigarette paper sheets loosely inserted into one another according to Fig. 2. The device according to the invention, which will be discussed later, is implemented in the cutting station 9. The buffer station 8 serves to temporarily accommodate the length of the strand 30 fed from the drive station 6 during the standstill during cutting.

After the cut, the packets 11 formed are conveyed away transversely to the strand direction. They lie against each other with their flat sides and form a new 0 wider, corresponding to the packet outline in cross section.
Strand 50, which is fed via a conveyor rail 12 to a packaging device (not shown), which provides it with the outer packaging designed as a removal packaging.

The principle of strand and packet formation is shown in Fig. 2. The uppermost paper band 2 is folded lengthwise around its longitudinal center line 41 and is thus

cut V-shaped with the legs 42,43. The "V" is open to the left as shown in Fig. 2. The paper strip 2' underneath has its longitudinal center line 41' on the left as shown in Fig. 2 and is also V-shaped in cross section with the legs 42',43'. The "V" is open to the right. The upper paper strip 2 is inserted with its lower leg 43 laterally between the open legs 42',43' of the lower paper strip 2'. Overall, the successive paper strips 2,2' interlock with one another. The illustration in Fig. 2 shows that during the joining process only the two upper paper strips 2,2' are spread out in a V shape, but that the lower paper strips that have already been joined together are already flattened and form a partial strand with a flat, rectangular cross section. After the strand formed by the mutual joining of the individual paper strips 2 on its way through the strand forming stations 20 according to Fig. 1 from right to left - with a folded paper strip being added in each strand forming station 20 - has left the last strand forming station 20 and the finished strand 30 has been formed, all paper strips 2 lie closely against one another with their legs, as indicated in the lower part of Fig. 2. The finished strand 30 made up of all fifty or one hundred paper strips 2 also has a flat, rectangular cross-section.

The booklet, designated as a whole with 60 in Fig. 3, holds one of the packets 11 of cigarette paper sheets indicated in Fig. 1 and consists of a flat outer box 51 with a front flat side 52, a rear flat side 53, two longer side surfaces 54 and two shorter side surfaces 55. The front flat side 52 has a slot 56 running the length of the booklet 60, from which a cigarette paper sheet 57 protrudes. When this cigarette paper sheet 57 is pulled out, the next cigarette paper sheet appears. The main quantity, however, is

constantly enclosed by the outer box 51. A closure lid can be pivoted about an axis 58 corresponding to a longer side of the rectangle on the rear flat side 3, one edge of which has an angle 54' corresponding to the narrow side surface 54 and which otherwise covers the front flat side 52. In the delivery state, the closure lid 59 is connected to the outer box in a suitable manner, i.e. closed.

According to Fig. 4, the strand 30 runs from right to left into the cutting station, designated as a whole by 9. The first unit of the cutting station is the intermittent drive 21, which is mounted on a vertical support plate 2 3 and has two drive belts 22 arranged one above the other, the strands of which, facing the flat sides of the strand 30 and supported by horizontal support rails 22', rest on the flat sides and intermittently take the strand along a distance corresponding to the length of the cigarette paper packet. Immediately downstream of the drive device 21 is a support roller 24, the axis of which runs horizontally and perpendicularly to the strand 30 and which rests against the strand 30 from below via a belt 25 forming the cutting base. The belt 25 can, for example, be 25 mm wide and 0.8 mm thick and consist of polyethylene. It is drawn off from a supply roll 39 (Fig. 1) and conveyed in the direction of the arrow and circles the support roll 24 from below in a meandering manner, by first wrapping around a deflection roll 46 from below, then through the gap between the deflection roll 46 and the support roll 24 and then over the top of the support roll, so that the meander apex is at the top, i.e. in the area of the contact point with the strand 30.

Above the strand 30, the knife carrier 26 is guided on a vertical straight guide 27. The flat knife 2 8 is clamped into the knife holder 26 and is guided in a plane perpendicular to the strand 30. The drive of the knife 2 8 during its up and down movement is carried out via a crank rod 2 9 and a crank disk

31, which is driven at a selectable speed. When the knife 28 comes down on the strand 30, it is cleanly severed at the cutting point 45 (Fig. 5), because the knife 28 penetrates into the relatively hard, but flexible, band 25, without, however, cutting it. The punching knife 28 runs out in the band 25 in the area of its lower dead center. The punching knife 28 is a flat blade similar to a razor blade, only thicker, for example about 0.5 mm thick, which is clamped between the knife holder 26 and a clamping piece 26' (Fig. 6).

During the cut, the cigarette paper packet that is about to be severed is located with its leading end in a guide channel 32 of rectangular cross-section that surrounds it. The guide channel 32 prevents the cigarette paper packet from springing open and falling apart during and after the cut. On the other side of the cutting point 45, the strand 30 is held between the bands 22 and support rails 22'.

While the punching knife 28 cuts off the strand 30, the latter remains stationary. As soon as the cut has been made and the punching knife 28 has emerged upwards from the cross-section of the strand, the drive device 21 pushes the strand 30 by one cigarette paper length from right to left. The strand in turn pushes the cigarette paper packet that has just been cut off through the guide channel 32. The separated cigarette paper packet is then transferred to a transfer station and onto a carrier 34 with prongs 35 protruding in a horizontal plane like a fork. Immediately, a pusher 36 that can be moved up and down on a vertical straight guide 37 is lowered onto the cigarette paper packet. This pusher has several, in the embodiment three, pusher attachments 38 that protrude vertically downwards, which can grip between the prongs 35, but initially come to rest on the top of the cigarette paper packet and push the cigarette paper packet onto the carrier 34.

hold down. The carrier 34 holds the fork tines 35 and then retracts under the cigarette paper packet according to Fig. 4, so that the cigarette paper packet located in the transfer station 33 is pressed down onto the last cigarette paper packet 11 already located in the cross conveyor 12. As soon as the fork tines have reached the very back of the outline of the cigarette paper packets 11 in the cross conveyor 12, they reach the gaps between the pusher attachments 38 when the carrier 34 moves forward again, namely now above the last cigarette paper packet 11. The pusher attachments 38 press the strand of cigarette paper packets 11 located in the conveyor 12 further through the fork tines 35. The pusher 36 then moves up again and releases the cross-section of the guide channel 32 for the next cut cigarette paper packet to move up.

The lifting movement of the knife holder 26 determines the working cycles of the intermittent feed device 21.

0 It also determines a slow rotation of the

Support roller 24 with the belt 25. The support roller 24 is knurled on its circumference so that it can be driven along properly. The support roller 24 can rotate further by such an angle after each knife stroke or even after a few, for example three, knife strokes that the next impact of the punching knife 28 on the belt 25 takes place about 0.2 mm next to the last impact point of the punching knife 28. In this way, parallel markings are created on the belt 25, lying next to one another at the specified distance and running transversely to the belt 25, which are designated 45' in Fig. 5. The belt is slowly pulled along in the direction of the arrow from a supply roll 39 (Fig. 1) as shown in Figs. 4 and 5 and then, when it has served its purpose as a cutting base, is fed back into a waste box 44. Due to the one-sided stress caused by the penetration of the punching knife 2 8 and the formation of the markings,

The band 25 maintains a considerable twist, which ensures proper
Rewinding is made more difficult. It is therefore easier to let the tape 25 run back into the waste box 44 in the tangled arrangement that occurs by itself.

The path of the belt 25 over the support roller 24 is indicated in bold in Fig. 6.

Claims (7)

1. Device for cross-cutting a strand-shaped structure, intermittently conveyed in the strand direction made of paper, cardboard, plastic or the like with a flat punching knife (28) which can be moved in a plane perpendicular to the strand (30) from one side against the strand and through the strand, with a fixed support for the strand (30) on the other side of the strand (30) and with a cutting base arranged between the strand (30) and the support in the form of a flat structure which is essentially still dimensionally stable under the cutting forces, but not hard, characterized, that the support is formed by a rotatably driven support roller (24) arranged with its axis transverse to the strand (30), and the cutting base is formed by a belt (25) which wraps around the support roller (24) with the apex directed towards the cutting edge (45) and is moved by the support roller (24).
20 D-40239 DÜSSELDORF MULVANYSTRASSE 2 TELEPHONE 49 / 211 / 96 145 - 0 FAX 49 / 211 / 96 145 - 20 D-45133 ESSEN ■ FRÜHLINGSTRASSE 43 A TELEPHONE 49 / 201 / 84 230 - 0 FAX 49 /201/84 230 - 20 POSTGIROL COLOGNE (bank code 370 100 50) 115 2 11 - 504 2. Device according to claim 1, characterized in that the belt (25) is guided approximately meander-shaped over the support roller (24). 3. Device according to claim 1 or 2, characterized in that the support roller (24) is roughened on its circumference in the area of the belt (25). 4. Device according to one of claims 1 to 3, characterized in that the support roller (24) is rotatably driven in dependence on the strokes of the punching knife (28). 5. Device according to claim 4, characterized in that the support roller (24) can be rotated further intermittently by a small angular amount at least after a few strokes of the punching knife (28). 6. Device according to claim 5, characterized in that the further rotation steps on the belt (25) correspond to a feed of approximately 0.15 to 0.25 mm. 7. Device according to one of claims 1 to 6, characterized in that the band (25) consists of plastic.