DE19629561A1 - Rotary cutting machine for printing industry - Google Patents

Abstract

The machine has a driven upper knife (1), interacting with a partially overlapping rotary element below it. The rotary element is formed by a lower knife (2) with at least one cutting blade. It is located inside the upper knife, when seen from the transportation plane of the material to be cut. Both knives turn in the direction of transportation, so that cut-off material parts are thrown upwards. The lower knife turns at a speed considerably above the material speed. The upper knife turns at a speed corresponding approximate to the material speed.

Description

The present invention relates to a rotation cutting machine according to the preamble of the claim 1.

Rotary cutting machines are used for a wide variety Applications used. In the paper processing Industry come in rotary cutting machines different areas of application. For example, in print shops Rotary cutting machines used to the already cut printed pages to the desired format. In this application, rotary cutting machines have the great advantage that with these a continuous Production flow can be ensured while at other cutting machines, for example face cutting machines the products to be cut are stopped need to make the cut. With a rotation cutting machine, however, can with continuous product flow, for example on a conveyor belt, cutting the Product.

Typically used in the printing industry cutting products in so-called sheds. That means several products are stacked on top of each other, however, the products do not overlap completely, but rather only partially, so that there is a scaly stack, the so-called scale.

This scale extends over the edges to be cut Transport device, for example a conveyor belt, in front. If the scale on the rotary cutting machine, whose  Knife relative to the edge of the transport device or Dandruff are adjustable, conveyed over, cuts the rotary cutting machine the protruding edge of the Dandruff.

The rotary cutting machines used today work with an upper knife whose axis of rotation is above the conveyor level of the scale is arranged and with a small rotating lower knife or a standing one Counterplate cooperates. The cut through the Scale exclusively from the top knife, wherever only supports against the lower knife or the counter plate. The Upper knives are used as simple one-piece knives executed or as a segment knife, the circumference in are spaced at certain intervals. This Knives can be a straight cut or a sawtooth have a cut.

With these rotary cutting machines are in use from normal magazine paper shed to about 60 Pages can be cut easily with sufficient accuracy.

With thicker scales it occurs with the conventional Rota tion cutting machines in the area of overlap Pages in the outlet area for tears in the paper most cases cannot be tolerated.

The object of the invention is therefore a rotary cutter machine with which it is possible to create even thick ones Paper scales with sufficient accuracy without Cutting cracks.

This object is achieved by the features of patent claim 1 solved. The new type of rotary cutting machine according to the Invention has a driven upper knife, the  The axis of rotation is arranged above the transport plane which promotes the material to be cut. This waiter knife interacts with a lower knife, whose rotation axis is arranged below the transport plane and - that has a cutting edge. Both knives overlap slightly compliant, the upper knife from the transport level seen inside is arranged and the lower knife outside. The The upper knife rotates in the conveying direction and also the lower knife rotates in the conveying direction so that the cut off Parts of the goods are thrown upwards.

According to an advantageous embodiment, the bottom rotates knife with a peripheral speed that is well above the conveying speed of the material to be cut lies whereas the upper knife at a peripheral speed rotates, which corresponds approximately to the conveying speed. At usual scales has an um for the lower knife proven speed, which is about twice the Conveying speed is. Likewise, an over lapping the upper and lower knife by approx. 2 mm is advantageous proven.

The knives can have saw teeth or be smooth be sanded. A bevel has proven to be advantageous one of the knives or both knives on the circumference proven so that the peripheral edge tapers. To this Way, the friction that arises when the knife cuts through the paper.

The upper and lower knives can be bevelled on the circumference that the beveled surfaces face each other. Such a design is in connection with the Description of the specific embodiment in more detail described.  

The knives can be designed in different ways. However, special segment knives have proven themselves are composed of a large number of segments. According to a preferred embodiment, the knife is made even made of hard metal in a circle segments. These segments are on a knife holder mounted and form the outer area of the knife. are Upper and lower knives designed in this way, act the meeting segments like scissors and sever the scales clean.

The construction of the knives as segment knives has numerous Advantages. The knives can be set in the factory, see above that no adjustment of this by the customer is required is. The knife is regrinded by the customer not necessary as damaged or worn Segments can be easily exchanged.

Both knives can be designed as a complete knife unit that are only on the desired page of the Transport device must be installed without any settings would have to be made.

The segments can be clamped to a knife carrier screws are clamped. Of course, too other types of fastening, such as screwing etc. possible. Around to determine the position of the segments, this and the Knife carriers have a positive connection, which the assembly of the segments only in one position allowed. For this purpose, the segments can be provided with grooves be engaged in the projections of the knife holder. If the segments are clamped over clamping pieces, so can also be provided on these projections with Throats of the segments engage.  

A construction with 18 segments per has proven itself Knives and the manufacture of hard metal knives.

The segments can be identical and circular form fit against each other. By a sawtooth Design of the contact surface of the knife holder for the Segments can be a simple design sawtooth-shaped peripheral edge of the knife can be achieved which is explained in more detail using the exemplary embodiment.

The segments can be in the area with a free be provided with the angle by which the cutting resulting friction can be reduced. For this clearance angle have proven themselves around 2.5 °.

The knives are advantageously provided so that the Upper knife and lower knife in the neutral line of the Dandruff, d. H. regarding the height or thickness of the scale meet in the middle of the scale. This is according to one preferred embodiment achieved in that the Upper knife and lower knife slidably arranged and both knives are pneumatically in the direction of the scale be pushed. Through a common pneumatic Actuation of the two knives can be achieved that the knives automatically move to the neutral line of the Adjust scale.

An adjustment of the knives in a direction perpendicular to the Conveying direction for setting the cutting width can be over Adjustment motors take place. Such adjustment motors can also used to put the knife on the neutral line adjust.

In order to improve the guidance of the material to be cut, can be provided a pressing device, at least  an edge of the material to be cut with at least one Investment element that leads from above or below to the property exerts a certain pressure. Of course you can too Appropriate pressure should be exerted from both sides.

The contact element can by at least one press belt are formed, advantageously two press belts are provided which are opposite to each other and by exert pressure on the goods above and below.

The press belt or contact element should be movable be stored and pressed pneumatically in one direction will. The storage of the knives and the pressing device can be connected to each other so that they too can be moved together pneumatically so that the knives meet in the neutral line of the scale.

The invention will be described in more detail below with reference to a preferred one Described embodiment.

Fig. 1 shows the essential part of a rotary cutting machine according to the invention in cross section.

Fig. 2 shows a segment knife of the rotary cutting machine according to the invention in cross section.

Fig. 3 shows a knife holder of the segment knife in plan view.

Fig. 4 shows a segment of the segment knife in cross section.

In Fig. 1 the essential part of the rotary cutting machine is shown in cross section. The cutting machine described is used for cutting so-called scales. The scale to be cut and the transport device by means of which the scale is fed to the cutting machine is not shown.

However, the transport device is arranged so that the scale is fed perpendicular to the image plane, the scale being conveyed so that its neutral line lies in the plane 3 shown . A neutral line is the line defined by the middle leaf of the scale, ie the scale extends equally far below and above this line in terms of height.

An upper knife 1 is arranged above the level 3 and a lower knife 2 below this level 3. The upper knife 1 is connected via a central screw 8 to the upper drive shaft 6 and the lower knife 2 is connected via a central screw 9 to the lower drive shaft 7 . The drive shafts 6 , 7 are mounted in the housing of the cutting machine and are driven by means of gear wheels 10 and 11 .

Both knives 1 , 2 have a knife holder 13 which is equipped with segments 5 in the outer region. These segments 5 are made of hard metal and form the cutting edge of the knife 1 , 2 . The segments 5 are clamped by means of clamping pieces 14 which are fastened to the knife holders 13 by means of screws 15 .

On the side of the transport device, not shown, on which the knives 1 , 2 shown are also located, a press device 4 is arranged, which has an upper press belt 16 and a lower press belt 17 . These press belts 16 , 17 are guided by guides 18 . In order to be able to determine the position of the knives with the required precision and still allow manufacturing tolerances that ensure economical manufacture, four impression screws 19 are provided, by means of which the knives can be adjusted.

Before the operation of the cutting machine is explained, the structure of the knives 1 , 2 will be described. Fig. 2 shows a knife 1 , 2 in cross section. The knife holder 13 is identical for the upper and lower knife 1 , 2 , so that only the different equipment with segments 5 decides whether the knife should be used as the upper knife 1 or as the lower knife 2 .

The segment 5 shown above in FIG. 2 is mounted on the knife holder 13 as required for the upper knife 1 , whereas the segment 5 shown below is shown for use as the lower knife 2 . Of course, the segments 5 are mounted on a knife holder 13 only in one way or another. The illustration chosen is only intended to clarify that the knife holder 13 can be used for both upper knife 1 and lower knife 2 .

The segments 5 are fastened by means of clamping pieces 14 and clamping screws 15 to the knife holder. In order to precisely determine the position of the segments, each segment 5 is provided on both sides with grooves 19 , into which corresponding projections 20 on the knife holder 13 and clamping piece 14 engage.

The clamping piece, the clamping screw and the throats are not shown on the lower segment 5 . The exemplary embodiment described works with knives 1 , 2 which have a sawtooth profile. This sawtooth profile can be achieved by a corresponding shape of the segments 5 . However, this would make the production of the segments 5 complex, since in this case the segments 5 cannot simply be cut out of an annular element with the corresponding diameter.

In the present exemplary embodiment, the segments 5 represent elements of a ring which correspond to ring segments. That is, the outer circumference is parallel to the inner circumference. In order to still get the desired sawtooth shape, the radial contact surface on which the segments 5 rest radially on the inside of the knife holder 13 is sawtooth-shaped. This Ge design can be seen well from Fig. 3.

The knife holder 13 has a lateral contact surface 21 for the segments 5 and a radial contact surface 22 for the segments 5 . If the segments 5 are mounted on these contact surfaces 21 , 22 , the desired sawtooth-like cutting surface of the knives 1 , 2 is automatically obtained.

A segment 5 is shown in cross section in FIG. 4. The throats 19 are not shown for the sake of simplicity. As can already be seen in FIGS. 1 to 3, each segment 5 is chamfered in the outer region and tends to a tip. On the inclined surface opposite side of the segment 5 , a clearance angle of approximately 2.5 ° is provided, so that the segment 5 is also beveled in the region of the tip on this side of the segment 5 . This design ensures that the friction that occurs when the scale is cut is reduced, which on the one hand reduces the required drive power and on the other hand improves the cutting result.

The arrangement of the segments 5 is such that the heavily beveled side of the scale faces the upper knife, whereas the opposite side of the scale faces the lower knife. In the described embodiment, the overlap of the two knives is approximately 3 mm.

The operation of the cutting machine will be described below. The scale to be cut runs into the cutting machine perpendicular to the drawing plane. Before the scale reaches the cutting area and comes into contact with the knives 1 , 2 , it runs into the pressing device and is held and guided by the upper press belt 16 and by the lower press belt 17 . The press belts 16 , 17 are pressed pneumatically onto the scale, the same pressure being applied to both press belts 16 , 17 and the press belts 16 , 17 guiding the scale so that it is automatically brought into a position in which the neutral line of the Scale lies exactly at the point where the knives 1 , 2 also meet.

The scale then runs into the cutting area of the knives 1 , 2 and is cut by the scissors-like knives 1 , 2 . The upper knife 1 and the lower knife 2 who driven the opposite direction, the lower knife 2 rotates in the conveying direction, so that the scraps of paper are thrown from bottom to top after the cutting process. This enables simple extraction of the paper scraps, since extraction can take place from above and suction hoses or the like are generally easier to install from above than from below. In the lower area of the machine numerous devices are provided, which make the installation of a suction device difficult, whereas access to the cutting machine is easy to manufacture from above.

The speed of the upper knife 1 is dimensioned such that the peripheral speed of the upper knife 1 is slightly above the conveying speed. The lower knife 2 is driven at a speed that gives a peripheral speed for the lower knife 2 , which corresponds approximately to twice the speed För.

In this cutting machine, the knives 1 , 2 are stored in a common knife block and driven by a common drive source. The knife block is in turn slidably mounted in the cutting machine and can be moved by means of adjustment motors. With regard to the desired height of the knives, these are automatically adjusted so that the point at which the two knives 1 , 2 meet lies in the area of the neutral line of the scale.

If a knife 1 , 2 is damaged or worn, it can simply be removed from the knife block after loosening the central screw 8 , 9 and exchanged for a replacement knife. The cutting machine's downtime is therefore short. The dismantled knife can easily be equipped with new segments 5 by the user and then used again. An agile and complicated regrinding is not necessary.

The segments 5 are identical for the upper and lower knife 1 , 2 in this embodiment, so that only a small number of segments 5 must be kept in stock. The production of the segments 5 is relatively inexpensive, since they are easy to manufacture as simple ring segments even when a knife with a sawtooth-shaped cutting edge is realized.

Claims (27)

1. Rotary cutting machine with a driven upper knife, the axis of rotation of which is arranged above a transport plane on which the material to be cut is conveyed, and which interacts with a rotary element whose axis of rotation is arranged below the transport plane, the upper knife at least the rotary element partially overlapped, characterized in that the rotary element is formed by a lower knife ( 2 ) which has at least one cutting edge and is arranged inside the upper knife ( 1 ) as viewed from the transport plane, the upper knife ( 1 ) and the lower knife ( 2 ) in Direction of conveyance rotates so that the cut parts of the material are thrown upwards. 2. Rotary cutting machine according to claim 1, characterized in that the lower knife ( 2 ) rotates at an initial speed which is significantly higher than the speed of the material to be cut, whereas on the other hand the upper knife ( 1 ) rotates at a peripheral speed which is approximately the same Conveying speed speaks accordingly. 3. Rotary cutting machine according to claim 1 or 2, characterized in that the upper and lower knife ( 1 , 2 ) overlap about 2 mm. 4. Rotary cutting machine according to one of claims 1 to 3, characterized in that the upper knife ( 1 ) has a sawtooth-like cutting edge. 5. Rotary cutting machine according to one of claims 1 to 4, characterized in that the lower knife ( 2 ) has a sawtooth-like cutting edge. 6. Rotary cutting machine according to one of claims 1 to 5, characterized in that the upper knife ( 1 ) is chamfered at the beginning. 7. Rotary cutting machine according to one of claims 1 to 6, characterized in that the lower knife ( 2 ) is chamfered at the beginning. 8. Rotary cutting machine according to one of claims 1 to 7, characterized in that the upper and lower knives ( 1 , 2 ) are chamfered on the circumference so that the chamfered surfaces are opposite one another. 9. Rotary cutting machine according to one of claims 1 to 8, characterized in that the upper or / and the Un termesser ( 1 , 2 ) is designed as a segment knife, the scope of which is composed of a plurality of segments ( 5 ). 10. Rotary cutting machine according to claim 9, characterized in that the segments ( 5 ) are fastened to a knife carrier ( 13 ) which can be fastened on the drive axis of a knife ( 1 , 2 ). 11. Rotary cutting machine according to claim 10, characterized in that the segments ( 5 ) on the knife carrier ( 13 ) can be clamped. 12. Rotary cutting machine according to one of claims 9 to 11, characterized in that 18 segments per knife ( 1 , 2 ) are provided. 13. Rotary cutting machine according to one of claims 9 to 12, characterized in that the segments ( 5 ) are made of hard metal or ceramic. 14. Rotary cutting machine according to one of claims 9 to 13, characterized in that the segments ( 5 ) abut one another in a circle. 15. Rotary cutting machine according to one of claims 1 to 14, characterized in that the knives ( 1 , 2 ) are provided on the circumference with a clearance angle. 16. Rotary cutting machine according to claim 15, characterized characterized in that the clearance angle is approximately 2.5. 17. Rotary cutting machine according to one of claims 9 to 16, characterized in that the segments ( 5 ) have the shape of ring segments. 18. Rotary cutting machine according to one of claims 1 to 17, characterized in that the upper knife ( 1 ) and the lower knife ( 2 ) meet in the neutral line of the scale. 19. Rotary cutting machine according to one of claims 1 to 18, characterized in that the knives ( 1 , 2 ) are displaceable and the upper knife ( 1 ) is pressed pneumatically downwards and / or the lower knife ( 2 ) pneumatically upwards. 20. Rotary cutting machine according to one of claims 1 to 19, characterized in that the knives ( 1 , 2 ) are mounted displaceably in a direction substantially perpendicular to the conveying direction and can be adjusted by means of adjusting motors. 21. Rotary cutting machine according to one of claims 1 to 20, characterized in that at least the edges of the material to be cut with a pressing device is guided at least one contact element that from above and / or exerts a certain pressure on the goods below. 22. A rotary cutting machine according to claim 21, characterized in that the contact element is formed by at least one press belt ( 16 , 17 ). 23. Rotary cutting machine according to claim 22, characterized in that the pressing device comprises two press belts ( 16 , 17 ) which are opposite and exert pressure on the material from above and below. 24. Rotary cutting machine according to one of claims 18 to 23, characterized in that at least one system element is slidably mounted.   25. Rotary cutting machine according to claim 24, characterized ge indicates that the contact element pneumatically in a Direction is pressed. 26. Rotary cutting machine according to one of claims 19 to 25, characterized in that the storage of the knives ( 1 , 2 ) and the pressing device are interconnected. 27. Rotary cutting machine according to one of claims 19 to 26, characterized in that the knives ( 1 , 2 ) and the contact element are pneumatically displaceable so that the knives ( 1 , 2 ) meet in the neutral line of the scale.