Patent Application
20220355505
The invention generally relates to a packaging machine comprising an apparatus for cutting food packagings to size along a longitudinal direction.
Such packaging machines comprising an apparatus for cutting food packagings to size along a longitudinal direction are used in food processing lines to cut packagings to size in the longitudinal direction, i.e. in the product conveying direction, that are loaded with foods and subsequently sealed, but are still contiguous. In other words, the food slices, e.g. sausage slices or cheese slices, cut off by a slicer, in particular a high-performance slicer, are packaged portion-wise into contiguous packagings by the packaging machine and are subsequently cut apart into individual packagings by means of the apparatus for cutting food packagings to size along its longitudinal direction. These portions can also consist of only one slice or one piece.
So-called cutting units, which are formed from upper blades and lower blades, serve for the cutting to size of the food packagings. To achieve a good cutting quality, it is important that a spacing between the cutting blades or a contact force between the cutting blades of the cutting unit is set correctly. The contact force between the cutting blades has so far been set in that the cutting blades are manually displaced along their blade shafts until a desired contact force is set between the upper blade and the corresponding lower blade. This kind of setting of the contact pressure has several disadvantages. On the one hand, there is a risk that a careless user could injure himself through a contact with the cutting blade. Furthermore, the setting of the cutting blades with respect to one another requires time, expertise, and experience.
The German patent application DE 10 2018 128 110 A1 describes an improvement of the settability of the cutting blades with respect to one another. Here, a floating support of the cutting blades serves the purpose of the longitudinal cutting device being able to be configured in a simpler and more time-efficient manner. However, there is also a residual risk with this longitudinal cutting device that a careless user could injure himself through a contact with the cutting blade.
It is an object of the present invention to eliminate the disadvantages of the prior art and thus to provide a packaging machine comprising an apparatus for cutting food packagings to size along a longitudinal direction by means of which a safer setting of the apparatus is possible.
The object is satisfied by a packaging machine comprising an apparatus for cutting food packagings to size along a longitudinal direction in accordance with claim 1 and in particular in that an adjustment mechanism is provided, wherein the adjustment mechanism is coupled to an axially displaceable first cutting blade to displace the displaceable cutting blade in an axial direction.
In other words, the displaceable cutting blade or its blade mount does not have to be directly manually displaced on the respective blade shaft, but an adjustment mechanism is provided that allows an adjustment of the cutting blade without contacting the cutting blade or its blade mount. The adjustment mechanism consequently serves to adjust the cutting blade and possibly its blade mount by means of a component of the adjustment mechanism coupled to the cutting blade or its blade mount. The risk of a contact between the cutting blade and the user, i.e. the person setting the apparatus, can hereby be considerably minimized and the risk of injury on the setting of the cutting unit can thus be minimized.
Advantageous embodiments of the invention can be seen from the dependent claims, the description, and the drawings.
The packaging machine is preferably part of a food processing line. The food processing line can comprise a slicer, in particular a high-performance slicer, a portioning belt, a sorting and conveying line, an insertion station comprising a feeder or a picking robot, a sealing station, a labeling station, and/or a transverse separation station, i.e. an apparatus for a transverse cutting of the food packagings.
The apparatus defines an inner space that substantially corresponds to or includes the working region of the cutting apparatus. An engagement into this inner space usually generates a risk since the cutting blades of the apparatus are located in this inner space. Furthermore, the apparatus defines an outer region. In the outer region, there is no risk of coming into contact with one of the cutting blades. A boundary between the inner space and the outer region of the apparatus can be sectionally defined by an intervention protection. The intervention protection is preferably movably arranged so that it can be adjusted between a shielding position shielding the inner space and a release position releasing the inner space.
A first shaft, on which at least a first cutting blade is arranged, extends in the inner space. The first cutting blade is preferably rotationally fixedly arranged on the shaft. In this case, the first shaft can represent a drive shaft for the first cutting blade. For this purpose, the drive shaft can be rotationally drivable.
A second shaft, on which at least a second cutting blade is arranged, also extends in the inner space. The second cutting blade is preferably rotationally fixedly arranged on the second shaft. In this case, the second shaft can represent a drive shaft for the second cutting blade. To transmit a torque to the second cutting blade, the drive shaft can be rotationally drivable.
The first cutting blade and the second cutting blade together form a cutting unit arranged in the inner space. In other words, the two cutting blades form a unit by which the food packagings can be cut to size in the longitudinal direction. The two cutting blades preferably form a roller shear cutting unit, i.e. two cutting blades rotating in opposite directions and overlapping in the radial direction, in particular circular blades. All the features that are disclosed with respect to the general term “cutting unit” also apply to the more specific roller shear cutting unit.
To be able to set the cutting unit, the first cutting blade is axially displaceably supported on the respective shaft. The axial spacing and thus the axial contact pressure between the cutting blades of the cutting unit can hereby be changed. The displaceability of the first cutting blade can in particular serve to adjust the first cutting blade between an inactive position, in which the first cutting blade and the second cutting blade are spaced apart from one another, and an active position in which the first cutting blade and the second cutting blade are pressed toward one another. The cutting blade is preferably fixed on a blade holder and the blade holder is displaceably supported on the shaft.
In accordance with an embodiment, the adjustment mechanism projects from the outer region into the inner space of the apparatus. If the adjustment mechanism can be operated by hand, i.e. manually, it is advantageous if an adjustment element to be adjusted by the user, i.e. which serves to be gripped and adjusted by the user, is at least sectionally located in the outer region of the apparatus. Alternatively thereto, the adjustment element can indeed be arranged in the inner space, but remote from the cutting blades.
Alternatively to a manual adjustability of the adjustment mechanism, the adjustment mechanism can be coupled to a mechanical drive, in particular a motor drive. A mechanical drive is understood as a drive in which the driving force is applied by a machine, i.e. not by muscle power. Such a drive can be arranged in the inner space of the apparatus or in the outer region of the apparatus.
A manual adjustment element in the outer region of the apparatus and a mechanical drive both have the advantage that an axial contact pressure between the cutting blades can be set by the user without having to reach into the proximity of the cutting blade.
In accordance with an embodiment, at least two axially displaceable first cutting blades are arranged on the first shaft. The adjustment mechanism is preferably coupled to the axially displaceable first cutting blades such that the first cutting blades can be displaced at the same time in the axial direction. The setting time can hereby be minimized. The adjustment mechanism is advantageously coupled to the axially displaceable first cutting blades such that the axially displaceable first cutting blades can be displaced at the same speed in the axial direction.
In accordance with an embodiment, the two axially displaceable first cutting blades form a cutting unit arranged in the inner space together with the second cutting blade during operation. In this case, the adjustment mechanism can be coupled to the axially displaceable first cutting blades such that the first cutting blades can be displaced at the same time, in particular at the same speed and/or by the same path distance, in opposite axial directions. The spacings or contact forces between the first cutting blades and the second cutting blade, which is configured as a counter-blade, can hereby be set at the same time and the setup time can be further reduced.
Between the two first cutting blades, a disk can be arranged whose diameter is smaller than that of the cutting blades and whose thickness is adapted to a thickness of the second cutting blade, i.e. of the counter-blade. Packaging strips can hereby be clamped and transported away in a guided manner between the disk and the second cutting blade.
In accordance with an embodiment, the at least one axially displaceable first cutting blade is coupled to a cutting blade holder that is axially displaceably, but rotationally fixedly coupled to the first shaft. First coupling means are preferably provided at the cutting blade holder and cooperate with second coupling means of the adjustment mechanism to axially displace the axially movable cutting blade holder together with the at least one first cutting blade. The coupling means can be configured as mechanical coupling means. The force for adjusting the cutting blades can be transmittable from the adjustment mechanism to the cutting blade holder by means of a form fit.
In accordance with an embodiment, the first coupling means are formed as a peripheral groove at the cutting blade holder and the second coupling means of the adjustment mechanism are formed as an axially adjustable adjustment element engaging into the groove. Alternatively thereto, the first coupling means can be formed as a peripheral rib at the cutting blade holder and the second coupling means of the adjustment mechanism can be formed as an axially adjustable adjustment element engaging around the rib at both sides.
In accordance with an embodiment, the adjustment mechanism comprises a drive shaft extending in the direction of the first shaft and/or the second shaft. The adjustment mechanism can comprise a gear to convert a rotational drive movement of the drive shaft into a translatory movement of the at least one first cutting blade along the first shaft. The adjustment mechanism preferably comprises a plurality of gears to convert a rotational drive movement of the drive shaft into respective translatory movements of the first cutting blades along the first shaft.
In accordance with an embodiment, the drive shaft at least sectionally has a non-circular cross-section, for example a hexagonal cross-section. An axially secured sleeve comprising an inner peripheral surface adapted to the non-circular cross-section and an outer thread on an outer peripheral surface can be arranged on the sectionally non-circular cross-section. The adjustment element or a part coupled to the adjustment element can in turn have an opening that extends in the axial direction and that has an internal thread engaging into the external thread. The gear defined by the above-mentioned features is simple to manufacture and produces a precise conversion of a rotational movement of the drive shaft of the adjustment mechanism into a translatory movement of the adjustment element and of the cutting blade.
In accordance with an embodiment, the adjustment element is supported guided in the axial direction of the first shaft, in particular along a separate guide rod. A precise guidance of the adjustment element that is easy to be established is hereby made possible.
To monitor a position of the first cutting blades, a sensor can be provided to determine a position, in particular an angular position, of the adjustment mechanism. The sensor can in particular be configured to determine an angular position of the drive shaft of the adjustment mechanism. The apparatus can comprise a control device that evaluates, on the basis of the position determined by the sensor, during operation whether the at least one first cutting blade and the at least one second cutting blade contact one another with a necessary contact pressure to cut the food packagings to size.
In general, a determination device for determining a contact pressure between the at least one first cutting blade and its respective counter-blade can be provided. An apparatus for cutting food packagings to size usually has a blade drive that drives the at least one first cutting blade and, under certain circumstances, also the at least one second cutting blade or counter-blade, i.e. sets them into rotation. Via a measurement of the required drive torque of the blade drive in the idling state, i.e. when no food packagings are cut to size, a determination can be made whether the at least one cutting blade contacts its counter-blade with the necessary contact pressure. The required drive torque can be compared with reference values that were either predefined or determined during a reference operation. Thus, it is advantageous if a measurement device is provided that is configured to measure the drive torque of the blade drive. Furthermore, the measured drive torque can be used to adapt a contact pressure between the at least one cutting blade and its counter-blade if the contact pressure does not correspond to a desired contact pressure. For this purpose, the measurement device can be connected to an actuating drive for adjusting the adjustment mechanism. The blade drive preferably comprises at least one electric motor. In this case, the motor current can, for example, be measured and a contact pressure can be calculated therefrom.
If the at least one cutting blade is adjusted by a motor, a contact pressure between the at least one first cutting blade and its respective counter-blade can alternatively or additionally be measured via the required power of the actuating drive. If the actuating drive is configured as an electric motor, a determination can be made in a simple manner via a measurement of the motor current whether the at least one cutting blade is possibly pressed too strongly or too weakly against the respective counter-blade. Alternatively thereto, a contact pressure between the at least one first cutting blade and its respective counter-blade can be measured via a force measurement device, for example, via a strain gauge or another force sensor. Alternatively or additionally, a determination could also be made indirectly, for example via the measurement of an adjustment path of the at least one cutting blade relative to its counter-blade, whether the at least one cutting blade is possibly pressed too strongly or too weakly against the respective counter-blade.
In accordance with an embodiment, a regulation device is provided to regulate a contact pressure between the first cutting blade and its respective counter-blade to a desired value. The adjustment mechanism is then adjusted in dependence on the measured contact pressure such that the contact pressure between the at least one cutting blade and its respective counter-blade is as close as possible to a desired value stored in a control software of the packaging machine.
In accordance with an embodiment, a support of the at least one first cutting blade and/or the at least one second cutting blade, which can also be designated as a counter-blade when the first cutting blade and the second cutting blade form a cutting unit, is settable. For example, a support of the cutting blade can be settable such that a defined axis of rotation of the cutting blade can be changed with respect to its orientation. The so-called shear angle between the first cutting blade and its counter-blade is hereby settable. In other words, an angle between an axis of rotation of the first cutting blade and an axis of rotation of the second cutting blade is settable viewed in the conveying direction. Alternatively or additionally, the axis of rotation of the first cutting blade and/or of the counter-blade can be adjustable with respect to its position, for example vertically adjustable.
The object is also satisfied by a method of setting a contact force between a first cutting blade and a second cutting blade of a cutting unit of a packaging machine comprising the steps:
The method is thus based on the basic idea of setting the axially displaceable cutting blades such that the user does not have to touch either the cutting blade itself or a cutting blade mount that is usually present. Instead, the user actuates the adjustment mechanism, which is coupled to the at least one first cutting blade or its cutting blade mount, to set the spacing or the contact force between the cutting blades.
In accordance with an embodiment, the adjustment mechanism projects from the outer region of the apparatus into the inner space and the adjustment of the axial spacing between the first cutting blade and the second cutting blade of the cutting unit is effected by means of a manual actuation of an actuation element or adjustment element of the adjustment mechanism arranged in the outer region, for example a lever of the adjustment mechanism.
Alternatively thereto, the adjustment of the axial spacing between the first cutting blade and the second cutting blade of the cutting unit can be effected by means of a mechanical drive.
For the adjustment of the axial spacing between the first cutting blade and the second cutting blade, an adjustment element can be adjusted in the axial direction by a rotation of a drive shaft of the adjustment mechanism. In other words, the first cutting blade can be adjusted by means of a spindle drive.
To guide the movement of the adjustment element, for the adjustment of the axial spacing between the first cutting blade and the second cutting blade, the adjustment element can be adjusted along a guide rod that is in particular separate from the first shaft.
In accordance with an embodiment, at least two axially displaceable first cutting blades are arranged on the first shaft and are displaced at the same time, in particular at the same speed, in the axial direction by means of the adjustment mechanism during the setting of the apparatus.
The two axially displaceable first cutting blades can form a cutting unit arranged in the inner space together with the second cutting blade during operation and the first cutting blades can be displaced at the same time, in particular at the same speed, in opposite axial directions by means of the adjustment mechanism during the setting of the apparatus.
In accordance with an embodiment, a contact force between the at least one axially displaceable first cutting blade and the at least one second cutting blade can be measured directly or indirectly. A contact force between the at least one axially displaceable first cutting blade and the at least one second cutting blade or counter-blade can, for example, be measured in that a motor power of the blade drive or of the actuating drive is measured. Alternatively or additionally, an adjustment path of the first cutting blade relative to its counter-blade can be detected and a contact force can be calculated from the detected adjustment path.
In accordance with a further embodiment, the contact force or the contact pressure between the axially displaceable first cutting blade and the respective counter-blade can be regulated. For this purpose, desired values dependent on the respective packaging to be cut, i.e. dependent on the film type and/or film thickness, can be determined and stored in a database. A user can then, for example, in a menu item select the type of packaging to be processed. Depending on the packaging to be cut, the apparatus can retrieve a desired value for the contact pressure from the database and can regulate the actuating drive such that the contact pressure between the axially displaceable first cutting blade and the respective counter-blade substantially corresponds to the desired value retrieved from the database.
The invention will be described with reference to purely exemplary embodiments and to the enclosed drawings in the following. There are shown:
The packaging machine 12 that is shown in
The packaging machine 12 comprises a plurality of work stations following one another in the direction of transport T, namely a molding station 11 also designated as a deep-drawing machine or a thermoforming machine, an insertion station 13 for products 10 to be packaged, a feed station 14 for a top film 25 drawn off from a supply roll 25a, a sealing station 15 for connecting the bottom film 23 to the top film 25, a labeling station 16, a transverse separation station 17, and a longitudinal separation station 19, i.e. an apparatus 19 for cutting packagings 21 to size along a longitudinal direction.
The products 10 to be packaged are, for example, food products, here in the form of so-called portions, that each comprise a plurality of slices that were previously cut off from a loaf-shaped or bar-shaped food, such as sausage, cheese, ham or meat, by means of a food slicer (not shown).
A central control device 41 controls the operation of the packaging machine 12, including the work stations mentioned. Furthermore, the packaging machine 12 is provided with an operating device 45 that e.g. comprises a touch screen at which all the necessary information can be displayed to an operator and the operator can make all the necessary settings before and during the operation of the machine.
At the molding station 11, which comprises a top tool 11a and a bottom tool 11b, recesses 29, which are also designated as depressions, are formed in the bottom film 23 in a deep-drawing process in each case. The products or portions 10 mentioned are inserted into these recesses 29 at the insertion station 13. The insertion station 13 here comprises a so-called feeder of which two endless conveyor belts 13a, 13b are shown. Alternatively or additionally, the insertion station 13 can comprise a robot 50 that is likewise schematically shown here, e.g. in the form of a so-called “picker” that can be configured as a delta robot having a gripper 52 that comprises two buckets that jointly hold a respective portion 10. Such robots and their use in the handling of foods, in particular on the insertion of portions into recesses of packagings, are generally known to the skilled person so that further statements are not necessary here.
The bottom film 23 provided with the filled recesses 29 and the top film 25 are subsequently fed to the sealing station 15 that comprises a top tool 15a and a bottom tool 15b. The top film 25 and the bottom film 23 are connected to one another by means of these tools 15a, 15b. The recesses 29 and thus the packagings 21 formed by the top film 25 and the bottom film 23 are hereby closed. Sealing points 43 that extend transversely to the direction of transport T and that are also designated as sealing seams are schematically indicated in
Subsequent to the sealing station 15, the packagings 21 are still connected by the top film 25 and the bottom film 23 and therefore still have to be separated. The transverse separation station 17 and the longitudinal separation station 19 serve for this purpose.
The adjustment elements 133 also have an opening that has an internal thread 133a and that is in engagement with an external thread 139a associated with a drive shaft 135. In the embodiment shown, a sleeve 139, which is rotationally fixedly and axially fixedly fastened to the drive shaft 135, is provided on the drive shaft 135 for each adjustment element 133. The external thread 139a is formed at an outer peripheral side of the sleeve 139. The external thread 139a and the internal thread 133a together form a gear 137 that converts a rotational movement of the drive shaft 135 into a translatory movement of the respective adjustment element 133. Thus, a translatory movement of the respective first cutting blade 117 in the axial direction can be produced by a rotational movement of the drive shaft 135.
A guide rod 141 (see
On the setting of a spacing and a contact force between the first cutting blades 117 and the respective second cutting blade 123, the cutting blades 117 arranged adjacent to one another are moved toward one another and thus against the second cutting blade 123 arranged between the first cutting blades 123. So that adjacent adjustment elements 133 move toward one another on the rotation of the drive shaft 135, the internal threads 133a of the adjacent adjustment elements are equipped with opposite threads. In other words, one of the internal threads 133a has a right-hand thread and the internal thread 133a of the adjacent adjustment element 133 has a left-hand thread. So that both adjustment elements 133 move toward one another at a speed of the same magnitude, the internal threads 133a of the respective adjacent adjustment elements 133 have thread pitches equal in magnitude. The external threads 139a at the outer peripheral sides of adjacent sleeves 139 accordingly likewise have opposite threads.
In
As an alternative to the blade drive 143 comprising the belt 143a, a variant is shown in
As can in particular be seen in
In
Further elements of the adjustment mechanism 155 of the blade covers 155 can be seen in
| Number | Date | Country | Kind |
|---|---|---|---|
| 102021111559.0 | May 2021 | DE | national |
| 102021120316.3 | Aug 2021 | DE | national |
