DE102012001837A1 - Device for cross-cutting a flat object moved in the direction of transport - Google Patents

Abstract

Apparatus for cross-cutting a flat object moved in the direction of transport, in particular a continuously fed product strip, such as a film strand (4) covered with a wide cheese belt, perpendicular to a transport direction (T) of the article, comprising: a cross-cutting roll (1) provided with at least a knife-free counter-pressure roller (3), the cylindrical surface of which forms an abutment for the cross-cutting knife (2) during the cutting process, the axis of rotation (A2) of the counter-pressure roller (3) skewed relative to the axis of rotation (A1) of the crosscutting roll (1) so that during a cutting operation an axial cutting region (S) in which the crosscutting knife (2) is in cutting contact with the platen roller (3) is over the surface of the platen migrates, wherein the counter-pressure roller tei the pressure of the cross cutter Giving way.

Description

The invention relates to a device for cross-cutting a moving in the transport direction flat object, in particular a continuously fed product tape, such as a covered with a wide cheese strip film strand, wherein the transverse cutting is perpendicular to a transport direction of the article and wherein the device comprises a cross-cutting roller with is provided at least one axially to the cross-cutting roller arranged cross-cutting blade, and wherein a knife-free counter-pressure roller is provided, the cylindrical surface forms an abutment for the cross-cutting blade during the cutting operation.

Devices for cross cutting various objects are generally known from a number of production processes. The cross-cutting wide cheese bands is known. For example, the DE 10 2008 061 330 A1 a device for cutting pieces of predeterminable length from a cheese strip. The cheese strip is fed by means of a conveyor belt of the cutting device and initially cut into longitudinal strips. A cross cutting knife then cuts the longitudinal strips into pieces of cheese. This procedure is suitable as long as only the soft cheese needs to be cut. However, this device is not designed for cutting a film strand provided with the cheese, since the "chipping" of the film in one go is only possible with significantly higher cutting forces than cutting the quite soft cheese due to the tear strength of the film.

The difficulty in cross cutting a z. B. a cheese tape-providing film strand is therefore in the enormous burden that acts on the counter bearing, ie the component on which the film strand rests during cutting and which provides a counterforce for the cutting blade. For example, should a device after the DE 10 2008 061 330 A1 be used for such an application, the counter-pressure roller, which can represent the anvil, would have to be very large dimensions, so that the counter-pressure roller can provide a sufficient back pressure in the axially inner region. For this purpose, but then also the bearings of the platen roller would have to be significantly increased, since the platen would then have an enormous weight itself. Alternatively, the film width to be cut could be reduced, which is undesirable. In this respect, no wide strip of film provided with a food band has yet been cross-cut.

In particular, the processing of slices of soft and partly sticky cheeses high demands are placed on the production process. Due to the sometimes relatively low mechanical stability, these cheeses are difficult to process into individual slices, as in the required processing steps, such as cooling on belts, transporting, cutting, separating and packing always mechanical loads are applied to the cheese slices, which are the shape of the cheese slices can destroy. In order to stabilize the shape and to guide during the production medium carrier films are used on which the shaping takes place. The carrier film can also serve as a release sheet between a plurality of disks of a disk stack. However, the cheese strip must be cut into individual slices together with the carrier foil.

The DE 1 511 272 A discloses a rotary cutting device for producing straight cuts transversely to the conveying direction by continuously moving webs of paper or foil material. In order to avoid a chopping cut, ie chopping in one go, a knife roll with a square cross-section and a longitudinal knife mounted on one of the outer surfaces askew to the axis of the knife roll is provided. In order to obtain a straight-line section perpendicular to the transport direction, either a fixed counter-cutting edge or a counter-roller with a smooth surface is aligned in a skewed manner with respect to the knife roller. By this double skew arrangement, a section through the web is generated perpendicular to the transport direction. Due to the square cross section of the knife roller over the cutting width uniform distance between the intersection on the cutting edge and the intersection on the counter cutting edge and thus a homogeneous load during the cut is achieved. However, the device is quite complicated to produce, inter alia due to the skewed arrangement of the knife on the cutting edge and possibly the counter cutting edge on the counter roll.

It is therefore an object of the present invention to provide a device for cutting a moving object, in particular a continuously conveyed product strand, which performs a precise cut perpendicular to the direction of movement with a simple and compact mechanical structure and is relatively inexpensive to produce.

This object is achieved by a device according to claim 1. Preferred embodiments are described in the subclaims.

Due to the skewed arrangement of cross-cutting roller and knife-free counter-pressure roller initially results that the cross-cutting blade not exactly parallel on the counter-pressure roller rolls. It should be emphasized at this point that the cross-cutting roller does not have to be a roller in the true sense. It is sufficient for the implementation of the invention, when the transverse cutting blade rotates about a the "cross-cutting axis". In the case of a rigid counter-pressure roller and a rigid parallel to the axis of rotation of the cross-cutting roller aligned cross-cutting blade it would come in the skewed arrangement only at the intersection of the surface of the platen with the common solder to a touch, the common solder represents the shortest line connecting the two axes of rotation. That is, the cross cutter roll would contact the knifeless platen roller only at one point, ideally in the center of the platen roller. In the other axial areas, the cross-cutting blade would always have a distance from the surface of the counter-rolling roller, so that it would not be possible to cut the film across the entire width of the film.

However, according to the invention, the counter-pressure roller is not so rigid, but has as defined flexibility as possible, which the invention makes use of. The counter-pressure roller, which has no counter-cutting edge and in particular has a cylindrical surface or a continuous cylindrical surface portion, gives in quasi on the order of the y "projected diameter increase" of the cross-cutting roller resulting from the angle between the cross-cutting roller and the counter-pressure roller. As shown in the example description, this "projected diameter increase" can be calculated and adjusted accordingly via the geometric parameters. Thus, the point of intersection, which in practice is a short partial cutting line of sometimes a few centimeters, moves from one end to the other across the surface of the counter-pressure roller when the cross-cutting knife passes. The particular advantage is that substantially less pressure is generated on the counter-pressure roller over the partial cutting line than when it is acted upon over the entire length of the complete cutting line. An important aspect of the invention is that, during the cutting process, the countershaft rests elastically and with a corresponding pretension on the cutting edge, which may also be uneven due to tolerances.

The adjustment of the two rollers zueinender can be done by first the counter-pressure roller is brought into abutment with the cross-cutting blade in an end portion of the cutting edge, at this intersection, a sufficiently high initial cutting pressure must be present to cut the object. Then, taking advantage of the flexibility of the platen, the cross-cutting roll is guided with the cross-cutting blade along the cutting edge to the center to the common solder. If the cut is in the common lot, the largest deflection of the counter-pressure roller is given. If the rotation continues, the cut moves to the other end area, where the initial cutting pressure is restored with exact adjustment.

It is also possible to adjust the cutting blade as follows: The countershaft has at both ends an eccentric bearing, which also serves to make the countershaft oblique. When adjusting the front eccentric bearing is rotated from its rearward position forward until the countershaft rests against pressure rings of the cutting shaft. The rear eccentric bearing is already in the forward position. Now, the counter-pressure shaft is offset by the eccentric to the front parallel to the cutting shaft. The cutting blades can be adjusted according to the countershaft, so that there is a uniform light gap or a slight projection over the entire width. After adjustment, the front eccentric bearing is rotated back to its rear position until the countershaft rests again on the pressure rings of the cutting shaft. The countershaft is now at the desired angle at an angle to the blade shaft.

The skewing arrangement according to the invention thus has the effect that the rolling of the cross-cutting blade on the counter-pressure roller, viewed in the circumferential direction, takes place at different angular ranges of the cross-cutting roller in an indicated spiral. In other words, first the knife attaches to the object on one side, then the point of intersection moves across the object to the other side of the object to be cut. In this case, the deflection of the counter-pressure roller increases toward the middle, and then decreases again, the cutting pressure remains ideally constant over the entire width.

The essence of the invention is thus summarized in that while avoiding a "Hackschnitt", which takes place in one fell swoop, nevertheless, a perpendicular to the transport direction section is produced for example in a continuously conveyed film by knife cutting and not by shearing or biting. As already mentioned, can be significantly reduced by the inventive arrangement, the total pressure on the platen during the cut, so that it can be built with a smaller diameter and correspondingly less technical effort.

In this case, the invention also combines the following advantages: It is possible to dispense with a skewed arrangement of the cross-cutting blade on the transverse cutting roller, so that the Cross-cutting blade is cheaper to produce than such a cross-cutting blade, which are skewed on the cross cutting roller. At the same time, a comparatively quite weakly dimensioned counterpressure roller can be used, which is knife-less, that is to say has no counter-pressure edges or blades, and thus can also be produced inexpensively.

The article is cut through an "effective cut length" which is defined by the axial extent of that portion of the rolls in which the cross cut knife can roll on the back press roll. In general, the effective cutting length is determined by the length of the shorter component of cross-cutting blade and counter-pressure roller.

In the context of the present description, the term "rotation axis" of a roll is understood to mean a straight line through the two bearing axes of the roll. The axis of rotation is thus a theoretical construction line that does not bend in contrast to the central axis of the roll. When viewing the two axes of rotation along the common slot, both axes of rotation preferably have an angular offset between 0.2 ° and 10 °. The common lot here means a notional straight line which is perpendicular to the axes of rotation of both rolls. The common solder intersects both axes of rotation, in each case approximately in the middle of the effective cutting length. The use of the term rotary axis does not necessarily mean that the counter-pressure roller also has to rotate. The invention also works - though not so well - with fixed counter pressure surface. In this case, it is the intention of the invention that the counterpressure surface, in particular of the counterpressure roller, yields to the pressure of the crosscut knife.

The counterpressure roller can be dimensioned such that, in spite of the tension relative to the transverse cutting roller, a cutting pressure is generated in the region of the common solder which is not significantly above the cutting pressure in the axially outer regions of the effective cutting length, although the two rollers are arranged closer to one another there further outside. If the pressure on the counter-pressure roller is so homogeneous, this leads to a better cutting characteristic.

Preferably, the counter-pressure roller has a lower bending stiffness than the transverse cutting roller, in particular a maximum of 0.25 times, in particular a maximum of 0.1 times the flexural rigidity. This ensures that the counter-pressure roller relative to the cross-cutting roller has a significantly increased flexibility and can cling to the cross-cutting roller. Such conformability is required so that the counter-pressure roller can come into abutment with the cross-cutting blade even in axially outer regions of the effective cutting length. The lower bending stiffness is advantageously achieved in particular in that the counter-pressure roller has a smaller diameter than the transverse cutting roller, in particular a maximum of 0.5 times, in particular a maximum of 0.2 times the diameter. This also has the advantage that the counter-pressure roller can be dimensioned to be weaker than a stiff counter-pressure roller and is therefore less expensive to manufacture. A particular advantage is the smaller space required. For example, the upstream and downstream belts can approach very close to the cutting system.

By a defined insertion of a support from below support the cutting pressure can be selectively influenced and adjusted to the platen roller. Preferably, the counter-pressure roller is supported over its axial extent by a plurality of Abstützanordnungen, each forming an abutment for the counter-pressure roller on that side of the counter-pressure roller, which faces away from the transverse cutting roller. By such Abstützanordnungen the loads on the bearings of the platen, which are generated by the cutting process can be reduced again. The support assemblies may include force transfer means, such as spring means, which act in a direction which is oriented transverse to the axis of rotation of the platen roller. Specifically, the support arrangements can in particular have one or more support rollers, which can roll together with the counter-pressure roller in a portion of the effective cutting length. Due to the majority of the support arrangements used in a defined manner, it is possible to set the cutting pressure to different areas of the effective cutting length in a targeted manner.

The support arrangements preferably each have adjusting means for setting a supporting force, which applies the respective supporting arrangement to the counter-pressure roller. The ability to selectively adjust the support force, there are other benefits. Thus, the counter-pressure roller could theoretically be dimensioned so softly that it sags freely in a central region of the effective cutting length without the support arrangement. On the basis of the one or more support arrangements, it is then possible to set precisely the respective locally required cutting pressure. However, it is advantageous if the countershaft has a rigidity which leads to a cutting pressure with which the film can normally be cut. The supports then serve to further increase this cutting pressure when needed, for example, with thicker film or increasing wear.

Because of the significant reduction in cutting pressure, the invention offers the possibility of easily designing cross-cutting devices with an effective cutting length of more than 200 mm. There are even cutting lengths in the order of the roll lengths of 600 mm possible. In this case, the counter-pressure roller in particular a resistance torque between about 785 mm ³ and about 6283 mm ³ . The conveying speed of the cross-cutting cutting roller largely corresponds to the conveying speed of the object to be cut, in particular of a film strand provided with food band.

The invention will be explained in more detail with reference to FIGS. Herein shows

• a) in Frontansicht
• b) im Querschnitt gemäß der Schnittlinie B-B aus 1a) mit dem Querschneidemesser in Anlage mit der Gegendruckwalze,
• c) im Querschnitt gemäß der Schnittlinie C-C aus 1a) mit dem Querschneidemesser in Anlage mit der Gegendruckwalze,
• d) im Querschnitt gemäß der Schnittlinie D-D aus 1a) mit dem Querschneidemesser in Anlage mit der Gegendruckwalze,
• e) in Draufsicht;

1 the schematic arrangement of a cross-cutting roller and a counter-pressure roller of a device according to the invention

• a) in front view
• b) in cross section according to the section line BB 1a) with the cross-cutting blade in contact with the counter-pressure roller,
• c) in cross section according to the section line CC 1a) with the cross-cutting blade in contact with the counter-pressure roller,
• d) in cross section according to the section line DD 1a) with the cross-cutting blade in contact with the counter-pressure roller,
• e) in plan view;

2 an inventive device in perspective view;

3 the device after 2 in plan view;

4 the device after 2 in side view,

• a) aus jeweils einer Rolle,
• b) aus jeweils zwei Rollen;

5 a device according to the invention in side view with Abstützanordnungen

• a) each one roll,
• b) two rollers each;

6 several schematic representations of the rollers to illustrate the geometric conditions.

The 1 shows the schematic arrangement of the cross cutting roller 1 and the counter-pressure roller 3 a device according to the invention for cutting a film strand provided with a food band 4 in a direction transverse to a transport direction T of the film strand 4 , So a device for transverse cutting of the film strand 4 , The cross cutting roller 1 is with at least one cross cutting knife 2 Mistake. The cross cutting knife 2 is parallel to the axis of rotation A _{1 of} the cross cutting roller 1 aligned. In the present example, the cross cutting roller 1 exactly a cross cutting knife 2 on; but it is also possible that the cross cutting roller 1 two or more cross cutting knives 2 which then usually uniformly circumferentially distributed on the transverse cutting roller 1 are arranged. The device further comprises a counterpressure roller 3 , which is dimensioned much smaller than the cross cutting roller 1 and can bend significantly, like 1a shows. The cross cutting roller 3 has a rotation axis A ₂ , but not the center line of the counter-pressure roller, but by a straight line through the bearing axes of the bearing schematically illustrated 12 the counterpressure roller 3 is defined. In 1a the axes of rotation A appear parallel to each other. Out 1e but can be seen that the axes of rotation A ₁ , A _{2 have} an angular offset α to each other. 1e shows a plan view of the arrangement of the two rolls 1 . 3 with the plan view parallel to the common lot 8th the wind skew mutually arranged axes of rotation A ₁ , A ₂ takes place.

The deflection of the counterpressure roller 3 in 1a is exaggerated in the event that loads on the platen roller 3 on the part of the cross cutting knife 2 act, the cross cutting roller 1 So on the counter pressure roller 3 rolls. In 1b to 1d are sectional views in different areas of the effective cutting length shown along the section lines BB, CC and DD 1a , In 1b the section BB is shown. It can be seen that with respect to the transport direction T, the cutting process takes place earlier than in the areas of the effective cutting length corresponding to the representations of FIG 1c and 1d , due to the skew alignments of the two axes of rotation to each other. It can be seen that the counter-pressure roller 3 then always through the cross cutter 2 is pressed in an orientation in which the counter-pressure roller 3 in the region of the cutting point S then the same distance to the cross cutting roller 1 having. The cutting point S is the point of the surface of the platen roller 3 in a certain axial position with the cross cutter 2 can cooperate, so at the moment the cross cutting knife 2 on the counterpressure roller 3 rolls. The set of all points of intersection S results over the axial course of the counterpressure roller 3 a cutting line SL, which in 1e can be seen. When parallel to the cross cutting roller 1 aligned cross cutting knife 2 will the film 4 now first in the left area ( 1e ), wherein the cutting point S then moves along the cutting line SL to the right. So that a section is produced exactly perpendicular to the conveying direction in the film strand, is the transverse cutting roller 1 as well as the cross cutting knife 2 aligned exactly perpendicular to the conveying direction T. The Circumferential speed of the cross cutting blade corresponds to the conveying speed of the film strand 4 ,

Because of the counterpressure roller 3 is essentially allowed to bend, the back pressure roller 3 be correspondingly small dimensions. It should also be noted that, due to the deflection, in turn stresses are generated which maintain a contact pressure between the counterpressure roller and the transverse cutting roller. The counter-pressure roller is dimensioned so that a cutting pressure, that is, the contact pressure of the rolling on the counter-pressure roller cross-cutting blade over the axial length is substantially constant.

The 2 to 4 will be described together below. A crosscutting device is shown in detail, wherein the crosscutting roller has four crosscutters 2 has, each offset by 90 ° in the circumferential direction to each other. Again, the axes of rotation of the transverse cutting roller A ₁ and the platen roller A _{2 are} skewed to each other. 3 shows the view from above parallel to the direction of the public lot 8th , from which the angular arrangement of the axes is visible to each other.

In the 2 and 4 are also Abstützanordnungen 6 to detect at regular intervals along the axial length of the platen roller 3 are arranged and support them. The support arrangements 6 essentially comprise cylindrical punches 9 , which is approximately perpendicular to the axis of rotation A _{2 of} the counter-pressure roller 3 are aligned and in contact with the counterpressure roller 3 are. The stamps 9 are supported on a housing part 11 From the device and can forces coming from the counter pressure roller 3 on the support arrangement 6 be applied, forward axially. At the bottom of the housing part 11 are adjusting screws 9 provided with which the supporting force of the punches 9 can be adjusted.

In 5 are alternative embodiments of the support arrangement 6 shown. A support arrangement in each case comprises a support roller 7 ( 1a ) or several support rollers 7 ( 2 ), by means of which in each case a supporting force F on the counter-pressure roller 3 can be applied.

Based on 6 is simplified, the geometric relationship between the skewed orientation and the deflection of the platen illustrated. In 6a are superimposed the cuts through the rollers 1 . 3 according to the 1b and 1c shown. On the left is a section 3 ' the counterpressure roller in the area of the bearing in position P '(FIG. 6b ). In the middle (position P '' in 6b ) is cut 3 '' the bent counter pressure roller in the area of the common lot 8th shown. Above that is a fictional cut 3 ''' the counterpressure roller in the area of the common lot 8th shown, for the fictitious case, that the counter-pressure roller 3 does not bend. In the center of the roll, the deflection amounts to z.

The deflection z is simplified by the "height difference" of the cutting points between the cut 3 '' the bent counter pressure roller and the cut 3 ' the unbent counterpressure roller 3 shown.

The offset x in the conveyor belt direction of the counter-pressure roller 2 between the positions P 'and P''can be determined geometrically from the angular offset α and the half roll width B ( 6b ): tan (α) = x / B / 2 or x = 0.5B · tan (α)

Based on the offset x and the cutting radius R of the cross cutting knife 2 can then calculate the first component of the deflection z ₁ ( 6a ): R ² = (R - z) ² + x ² or z = -√ R² - x² + R

At B = 0.5 m, R = 0.3 m, a = 10 ° results in an axial offset x of about 4 cm. The deflection z is then approximately at 3 mm.

LIST OF REFERENCE NUMBERS

1

Cross-cutting roller

2

Sheeter knives

3

Backing roll

4

with cheese tape provided with foil

5

with a cheese slice provided with foil piece

6

support arrangement

7

support rollers

8th

Gemeinlot

9

stamp

10

adjustment

11

housing part

12

camp

T

transport direction

F

support force

S

cutting point

α

angular displacement

z

deflection

x

Offset in the conveying direction

D

diameter

B

roll width

P

position

A

axis of rotation

R

diameter radius

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102008061330 A1 [0002, 0003]
• DE 1511272 A [0005]

Claims (10)

Device for transversely cutting a flat object moving in the direction of transport, in particular a continuously fed product strip, such as, for example, a film strand covered with a wide cheese strip (( 4 ), perpendicular to a transport direction (T) of the article, comprising: a cross cutting roll ( 1 ) with at least one coaxial with the cross cutting roller ( 1 ) arranged cross-cutting knives ( 2 ), and a knife-free counterpressure roller ( 3 ), whose cylindrical surface during the cutting process an abutment for the cross-cutting blade ( 2 ), characterized in that the axis of rotation (A ₂ ) of the counter-pressure roller ( 3 ) skewed with respect to the axis of rotation (A ₁ ) of the transverse cutting roller ( 1 ), so that during a cutting operation an axial cutting area (S) in which the cross cutting blade ( 2 ) with the counterpressure roller ( 3 ) is in cutting contact, travels across the surface of the platen roller, the platen roller partially yielding to the pressure of the cross cutter blade. Apparatus according to claim 1, characterized in that the axis of rotation (A ₂ ) of the counter-pressure roller ( 3 ) with respect to the axis of rotation (A ₁ ) of the transverse cutting roller ( 1 ) is twisted by an angle (α) when viewed along the common billet, which is between 0.2 ° and 10 °. Apparatus according to claim 1 or 2, characterized in that the distance between the cross cutting roller ( 1 ) and the counterpressure roller ( 3 ) is set in the common lot so that both ends of the cross cutting knife ( 2 ) with the same cutting pressure on the counter-pressure roller ( 3 ). Apparatus according to claim 3, characterized in that the counter-pressure roller ( 2 ) and / or whose storage is such as to compensate the increased cutting pressure at the point theoretically resulting from the distance projection between the two ends of the counter-pressure roller ( 2 ) can yield such that the cutting pressure at this point corresponds almost to the cutting pressure at the ends. Device according to one of the preceding claims, characterized in that the counter-pressure roller ( 3 ) has a lower bending stiffness than the transverse cutting roller ( 1 ), in particular at most 0.25 times, in particular at most 0.1 times the flexural rigidity. Device according to one of the preceding claims, characterized in that the counter-pressure roller ( 3 ) has a smaller diameter than the transverse cutting roller, in particular a maximum of 0.5 times, in particular a maximum of 0.2 times the diameter. Device according to one of the preceding claims, characterized in that the counter-pressure roller ( 3 ) over the axial extent thereof by a plurality of support arrangements ( 6 ), wherein the support arrangements ( 6 ) each have an abutment for the counter-pressure roller ( 3 ) on the cross cutting roller ( 1 ) facing away from the counter-pressure roller ( 3 ) provide. Device according to the preceding claim, characterized in that the support arrangements ( 6 ) each have a support roller ( 7 ) or a plurality of mutually parallel support rollers ( 7 ). Device according to one of the preceding claims, characterized in that the support arrangements ( 6 ) each adjusting means for adjusting a supporting force (F), the respective support arrangement ( 6 ) on the counterpressure roller ( 3 ). Device according to one of the preceding claims, characterized in that the transverse cutting roller ( 1 ) and the counterpressure roller ( 3 ) each have a length of at least 200 mm.

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