This application claims priority to German Patent Application No. DE 10 2020 133 580.6 filed on Dec. 15, 2020, the disclosure of which is incorporated in its entirety by reference herein.
The invention relates to slicing machines, in particular socalled slicers, with which strands of an only slightly compressible product such as sausage or cheese are cut into slices in the food industry.
The invention further relates to a method for operating such a slicing machine.
Since these strands can be produced with a cross section that retains its shape and dimensions well over its length, i.e., essentially constant, they are called calibers or product calibers.
In most cases, several product calibers are cut side by side at the same time by cutting one slice at a time by the same blade, which moves in a transverse direction to the longitudinal direction of the product calibers.
The product calibers are pushed forward by a feed conveyor in the direction toward the blade, usually on an obliquely downwardly directed feed conveyor, and guided in each case through the product openings of a socalled cutting frame, at the front end of which the part of the product caliber protruding beyond it is cut off as a slice by the blade immediately in front of the cutting frame.
The slices generally fall onto a discharge conveyor, by means of which they are transported away for further processing.
During slicing, the product calibers are usually held at their rear end facing away from the cutting frame by a gripper (hereinafter also referred to as “caliber gripper”), which is provided with corresponding gripper claws for this purpose.
After the one or more product calibers have been cut from an initial length to a minimum final length, it is first necessary to remove the end pieces remaining on the grippers after cutting before reloading the slicer with new product calibers.
In principle, it can be sufficient to open the gripper so that the gripper claws holding the end piece of the product caliber release the end piece. However, if the product caliber is foodstuffs such as sausage or cheese mentioned above, the end piece may remain attached to the base body of the gripper even after the claws have been opened.
To overcome this problem, ejection devices provided on the gripper have already been proposed in the prior art, in which the end piece is removed from the gripper by means of a caliber contact element arranged on the gripper.
In slicing machines of this type, the caliber contact element is usually actuated by a mechanical coupling between the gripper claws and the caliber contact element, which means that the function of the gripper claws is directly coupled to the movement of the caliber contact element. The gripper claws themselves are often controlled by a drive unit, for example in the form of a pneumatic cylinder. For example, a corresponding pneumatic cylinder can be provided on each caliber gripper.
If the caliber contact element is to be actuated separately from the gripper claws and if additional gripper functions are to be implemented, a separate pneumatic cylinder must be provided for the actuation of the caliber contact element and for each additional gripper function, which results in a complex and thus economically disadvantageous embodiment of the gripper.
Furthermore, such pneumatic cylinders must be maintained with care, since even the smallest quantities of lubricant or unclean, in particular oiled, compressed air escaping from the pneumatic cylinder can lead to contamination of the foodstuffs to be processed in the form of the calibers. This effort is increased again accordingly with an increased number of pneumatic cylinders.
It is therefore the task according to the invention to provide a slicing machine, in particular a slicer, as well as a method for operating such a slicing machine, whereby a plurality of gripper functions acting independently of one another can be realized without requiring a separate drive unit for each gripper function.
With regard to the slicing machine, the object is solved in that the gripper unit comprises
According to the invention, it is possible to actuate both the gripper claws and the caliber contact element of a caliber gripper by means of the switching unit driven by one, preferably single, drive unit, without separate drive units, for example in the form of separate pneumatic cylinders, being required for this purpose.
In addition, the gripper claws and the caliber contact element can be actuated independently of each other, since the first partial distance of the plurality of partial distances is provided for actuating the caliber contact element, whereas the second partial distance is provided for actuating, for example, the gripper claws for opening or closing. Also, after the gripper claws have been opened, it is not absolutely necessary to actuate the caliber contact element at all, but only if this is also desired.
A partial distance can correspond to a part of the shifting distance that has a predetermined length along a shifting direction of the switching unit. The shifting distance can correspond to a working stroke that the switching unit can perform in the shifting direction.
Preferably, the switching unit can be displaced substantially in and against the transport direction of the calibers, i.e., the displacement direction of the switching unit can correspond substantially to the transport direction of the calibers or a direction opposite thereto or run substantially parallel thereto.
Furthermore, it should be noted that the drive unit may be provided not only for actuating a single product gripper of the gripper unit, but also for actuating a plurality of product grippers of the gripper unit. Accordingly, the slicing machine may comprise a separate drive unit for each product gripper or a, preferably single, drive unit for actuating a plurality of the product grippers.
Such a common drive unit is then preferably arranged stationary away from the gripper, for example on the guide for the gripper slide, and the drive movement is transmitted, for example via a control shaft, to the gripper slide which can be moved along a guide.
In principle, the drive unit can be embodied as a pneumatic drive unit. However, in order to counter the disadvantages of a pneumatic drive unit mentioned at the beginning, according to one exemplary embodiment the drive unit can be used as a, preferably electric, servo drive. In addition to increased ease of maintenance, a servo drive is also characterized by an increased maximum actuation speed compared to pneumatic drive units, which can, for example, enable faster opening and closing of the gripper claws. In addition, an actuation speed and/or an actuation force and/or a penetration depth of the gripper claws can be better adapted to the nature of calibers of different foodstuffs. Also, by means of such a servo drive, it is possible to determine the product hardness of a respective caliber at least approximately.
In principle, when actuated by the switching unit, the caliber contact element can act in the transport direction in such a way that the end piece of the caliber is pushed away from the caliber gripper and can then fall down onto an end piece conveyor in order to be conveyed away by means of the end piece conveyor. Furthermore, in order to be able to realize the function of a product recognition, i.e., to recognize whether there is a caliber on a track of the slicing machine assigned to the respective gripper, the caliber contact element can further act as a caliber feeler.
This can be achieved, for example, by the fact that when the switching unit is displaced substantially in the transport direction along the first partial distance, the caliber contact element is moved substantially in the transport direction and can act as a caliber ejector, and when the switching unit is displaced substantially in the opposite direction to the transport direction along the first partial distance, the caliber contact element is moved substantially in the opposite direction to the transport direction and can act as a caliber feeler. If the switching unit is moved substantially opposite to the transport direction along the first partial distance, this movement can thereby be caused by the caliber feeler contact element acting as a caliber feeler, which comes into direct or indirect contact with the caliber.
Furthermore, according to an exemplary embodiment, when the switching unit is displaced substantially in the transport direction along the second partial distance, the gripper claws can be actuated in such a way that they are moved into a release position in which they do not engage with the at least one caliber, i.e., release the caliber, and/or when the switching unit is displaced substantially opposite to the transport direction along the second partial distance, the gripper claws can be actuated in such a way that they are moved into an engagement position in which they engage with the at least one caliber.
Furthermore, the partial distances of the shifting distance may be immediately adjacent in the feeding direction. Therefore, several of the abovementioned functions can be realized via the switching unit with a comparatively small overall length of the axial shifting distance or a comparatively small working stroke of the switching unit.
In addition or alternatively, the switching unit can be embodied as a push rod which can preferably be actuated, i.e., displaced, by the drive unit in the manner described above. However, it is also conceivable in principle to embody the switching unit as a rotating unit, for example a spindle, which can be retracted or extended along the axial shifting distance by a corresponding rotary movement caused by the drive unit.
In principle, it is conceivable that the caliber contact element remains in its position extended in the transport direction after actuation by the switching unit and only returns to its original position when it is transferred back to its retracted position by contact with a further caliber. However, if the caliber contact element is also to be able to be actuated several times in succession by the switching unit, the caliber contact element can furthermore be assigned to a pretensioning element, in particular a spring, which is provided in particular for pretensioning the caliber contact element in the direction of the switching unit.
In further embodiments of this exemplary embodiment, the caliber gripper may further comprise a gripper body having a gripper plate relative to which the caliber contact element is displaceable, preferably substantially in and against the feeding direction, and preferably the pretensioning element, in particular the spring, is supported at one end on the caliber contact element or a part connected thereto and at the other end on the gripper base body, in particular the gripper plate or a part connected thereto.
In order to realize the coupling between the switching unit on the one hand and the gripper claws on the other hand, the switching unit, in particular the push rod, can be coupled to the gripper claws only along the second partial distance, and in particular comprise a switching unit toothing, for example a rod toothing, which is embodied and intended to mesh with a gripper toothing formed on the caliber gripper, for example a gear, during a shifting of the shifting unit along the axial shifting distance, in such a way that the gripper claws can be moved into the engagement position and the release position. The switching unit toothing and the gripper toothing can be embodied in such a way that they engage with each other only when the switching unit is moved along the second partial distance and are otherwise disengaged, i.e., decoupled. A movement of the switching unit substantially in the transport direction can thereby cause a transfer of the gripper claws from the engagement position to the release position, while a movement of the switching unit substantially opposite to the transport direction can cause a transfer of the gripper claws from the release position to the engagement position.
Alternatively, the switching unit, in particular the push rod, can comprise a system of rods which is coupled to the gripper claws and is embodied and intended to cooperate with the gripper claws during a shifting of the switching unit along the axial shifting distance in such a way that the gripper claws can be moved into the engagement position and into the release position. In particular, it is conceivable that the shifting unit and the gripper claws are coupled together along their entire shifting distance by the system of rods.
The axial shifting distance may further comprise a third partial distance, and upon shifting of the shifting unit along the third partial distance, the gripper claws of the at least one product gripper may be actuated to assume a maintenance position, for example. This can be advantageous not only for cleaning the caliber gripper, but also for simplified disassembly of the caliber gripper.
With regard to the method, the object is solved by the fact that, in order to operate a slicing machine, in particular a slicer, in particular a slicer according to the invention
It should already be pointed out that all the advantages and effects described with respect to the slicing machine according to the invention also apply to the process according to the invention.
In addition, the switching unit can be displaced substantially in and against the transport direction or substantially parallel thereto.
Furthermore, it is conceivable that the switching unit is coupled to the gripper claws along the entire shifting distance, or that the switching unit is coupled to the gripper claws only during its movement along a predetermined, in particular the second, partial distance of the shifting distance and otherwise remains decoupled therefrom.
Finally, the caliber contact element can be used as a product ejector when the switching unit is displaced substantially in the transport direction along one, in particular the first, partial distance and/or the caliber contact element can be used as the caliber feeler when the switching unit is displaced substantially in the opposite direction to the transport direction along one, in particular the same, partial distance.
Embodiments according to the invention are described in more detail below by way of example. They show:
It can be seen that the basic structure of a slicer 1 according to the state of the art is that a cutting unit 7 with a rotating sickle blade 3 is fed with several, in this case four, product calibers K lying next to each other transversely to the transport direction 10 in a feed unit 20, from the front ends of which the rotating sickle blade 3 simultaneously cuts off a slice S in each case.
For this purpose, the feed unit 20 comprises a feed conveyor 4 in the form of an endless, circulating feed belt 4, the upper run of which can be driven at least in the transport direction 10 and also in opposition thereto, the calibers K lying side by side in the width of this feed conveyor 4 being arranged on the feed belt 4 spaced apart in the transport direction 10 by spacers 15 which project outwardly from the feed belt 4 with respect to the direction of circulation, i.e., upwardly from the upper run.
For slitting the product calibers K, the feed conveyor 4 is in the inclined position shown in
The rear end of a caliber K—lying in the feed unit 20 is held positively in each case by a gripper 14a-d with the aid of gripper claws 16. These grippers 14a-14d, which can be activated and deactivated with respect to the position of the gripper claws 16, are attached to a common gripper unit 13, which can be fed along a rod shaped gripper guide 18 in the transport direction 10.
Both the feed of the gripper unit 13 and the feed conveyor 4 can be driven in a controlled manner, but the specific feed speed of the calibers K is effected by a so-called upper and lower product guide 8, 9, which engage the upper and lower sides of the calibers K to be cut open at their front end regions near the cutting unit 7:
For the slicing, the front ends of the calibers K are each guided through a product opening 6a-d present for each caliber, which are formed in a plateshaped cutting frame 5, which is a component of the cutting unit 7, in that the cutting plane 3″ runs directly in front of the front, obliquely downward pointing end face of the cutting frame 5, in which the sickle blade 3 rotates with its cutting edge 3a and thus cuts off the projection of the calibers K over the cutting frame 5 as a slice S. The cutting plane 3″ runs perpendicular to the upper run of the feed conveyor 4 and/or is spanned by the two transverse directions 11, 12.
The inner circumference of the product openings 6a-d of the cutting edge 3a of the blade 3 serves as a counter cutting edge.
The product openings 6a-d of the replaceable cutting frame 5 are approximately adapted to the cross section shape and size of the calibers K to be cut, but since their cross section size is subject to production-related fluctuations, the cross section of the eye product glass openings 6a-d is generally somewhat larger than the cross section of the caliber K to be cut.
In order to nevertheless achieve a good cutting result and to be able to control parameters such as the contact force of the caliber K on the inner circumferential surface of the product opening 6a-d and other parameters, the bottom and top product guides 8, 9, each in the form of a conveyor belt, are provided, of which the bottom product guide 9 with its upper run and the top product guide 8 with the lower run of the corresponding conveyor belt are in frictional contact with the underside and top side of the caliber K respectively.
Since both product guides 8, 9 can be driven in a controlled manner, in particular independently of one another, they determine the—continuous or clocked—feed speed of the calibers K through the cutting frame 5. Preferably, the two product guides 8, 9 are present in the 1st transverse direction 11 separately for each caliber K and can be driven controlled.
In addition, at least the upper product guide 8 is displaceable in the 2nd transverse direction 12—which is perpendicular to the surface of the upper run of the feed conveyor 4 tilted up into the cutting position—for adaptation to the height H of the caliber K in this direction. Furthermore, at least one of the product guides 8, 9 can be embodied to be pivotable about one of its deflection rollers 8a, 8b, 9a, 9b in order to be able to change the direction of the run of its conveyor belt, resting against the caliber K, to a limited extent.
The slices S, which stand in the space inclined corresponding to the inclined position of the feed unit 20 and cutting unit 7 during slicing, fall onto a discharge unit 17 which starts below the cutting frame 5 and runs in the pass through direction 10* and which in this case consists of several discharge conveyors 17a, b, c arranged one behind the other with their upper runs approximately aligned in the pass through direction 10*, one of which can also be embodied as a weighing unit.
In this case, the slices S fall either directly onto these discharge conveyors 17a-c, as shown for example in
Below the feed unit 20 there is also an approximately horizontally running end piece conveyor 21, likewise in the form of an endlessly circulating conveyor belt, which starts with its front end below the cutting frame 5 and directly below or behind the discharge unit 17 and with its upper run transports off end pieces falling thereon from there to the rear against the pass through direction 10*.
For this purpose, at least the first discharge conveyor 17a in the pass through direction 10* can be driven with its upper run counter to the pass through direction 10* so that an end piece falling thereon, for example, can be transported to the rear and falls onto the lower-lying end piece conveyor 21.
The upper product guide 8 can be driven by a drive unit 8* acting in the region of the deflection roller 8a, while the lower product guide 9a can be driven by a drive unit 9* acting in the region of the deflection roller 9a. Since, as already explained with
The special feature according to the invention will now be described in more detail with reference to
In the Exemplary embodiments shown, the gripper claws 16 and the caliber contact element 26 are actuated by a switching unit 30 in the form of a push rod 30, which can be moved in and against the transport direction 10 by means of a drive unit 29 in the form of an electric servo drive 29. The push rod 30 can be moved along an axial shifting distance 27, which will be explained in more detail with reference to
The force transmission between the push rod 30 and the gripper claws 16 can be effected, on the one hand, by meshing a rod toothing 30.1a formed on the push rod 30 with a gripper toothing 14.1 formed on the caliber gripper 14, as shown in
In order that the caliber contact element 26 can also be actuated several times in succession by the push rod 30, a preloading element 31 in the form of a spring 31 is also assigned to it, which is supported at one end on the stripper plate 32 and at the other end on a flange 25.1 of the caliber contact element 26 and is provided to preload the caliber contact element 26 in the direction of the push rod 30. The actuation of the caliber contact element 26 in the transport direction 10 can thereby be effected by an end of the push rod 30 located in the transport direction 10 approaching the flange 25.1 of the caliber contact element 26 and pushing it away from the stripper plate 32 in the transport direction 10. By the action of the spring 31, the caliber contact element 26 can be moved back again against the transport direction 10 in the direction of the scraper plate 32, preferably until it abuts against the scraper plate 32.
Furthermore, in the exemplary embodiment shown, the caliber contact element 26 can also act as a caliber feeler 26 for detecting a caliber K. Namely, if the caliber gripper 14 is moved together with the gripper unit 13 towards a caliber K, the caliber contact element 26 moves against the transport direction 10 in the direction of the scraper plate 32. This in turn also moves the push rod 30 driven by the servo drive 29 against the transport direction 10, which can be detected by a control 1* of the slicer 1 that is operatively connected to the servo drive 29, and can accordingly indicate the presence of a caliber K.
Alternatively, as shown in
Finally,
After the caliber K has been cut except for a remaining end piece KR, the gripper claws 16 are first opened, i.e., moved back toward their release position, to release the end piece KR. This state is shown in
If the end piece KR remains attached to the caliber contact element 26 or the scraper plate 32, the push rod 30 can be moved further by the first partial distance 27a in the transport direction 10 by means of the servo drive 29, as finally shown in
Subsequently, the operation described above can again be repeated starting from the working position shown in
It should be added that the axial shifting distance 27 may further comprise a third partial distance 27c, and that upon shifting of the push rod 30 along the third partial distance 27c in the transport direction 10, the gripper claws 16 of the at least one caliber gripper 14 are actuated to assume a maintenance position shown in
Furthermore, it should be added that in the event that the caliber gripper 14 is formed as shown in
1 slicing machine, slicer
1* control
2 base frame
3 blade
3 rotation axis
3″ blade plane, cutting plane
3
a cutting edge
4 feed conveyor, feed belt
5 cutting frame
6
a-d product opening
7 cutting unit
8 upper product guide, upper guide belt
8.1 contact run, lower run
8
a cutting side deflection roller
8
b deflection roller facing away from the cutting side
9 bottom product guide, lower guide belt
8.1 contact run, upper run
9
a cutting side deflection roller
9
b deflection roller facing away from the cutting side
10 transport direction, longitudinal direction, axial direction
10* pass through direction
11
1. transverse direction (width slicer)
12
2. transverse direction (height direction caliber)
13 gripper unit, gripper slide
14.14a-d gripper, product gripper
14.1 gripper toothing
15 spacer
15′ support surface
16 gripper claw
17 discharge conveyor unit
17
a, b, c portioning belt, discharge conveyor
18 gripper guide
19 height sensor
20 feed unit
21 end piece conveyor
22 end piece container
25 gripper body
25.1 flange
26 caliber contact element, caliber ejector, caliber feeler
27 shifting distance
27
a-c partial distance
28 clutch
29 drive unit, servo drive
30 switching unit, push rod
30.1a shift unit toothing, rod toothing
30.1b system of rods
30.1b′ first rod
30.2b′ second rod
30.2b first pivot axis
30.3b second pivot axis
30.4b third pivot axis
31 preloading element, spring
32 gripper plate, scraper plate
37 spacer
K product, product caliber, caliber
KR end piece
S slice
Number | Date | Country | Kind |
---|---|---|---|
102020133580.6 | Dec 2020 | DE | national |