Slicing machine and method for slicing food

Abstract

A slicing machine (1), in particular a slicer, for slicing foodstuffs, comprising: a feeding unit (20) configured to feed at least one product caliber (K) along a feeding direction (10), and a cutting unit (7) configured to slice the at least one product caliber (K) into slices (S), wherein the cutting unit (7) comprises a knife (3) which is rotatable about a rotational axis (R), and wherein the cutting unit (7) is designed and intended to perform a disengagement movement (A) for carrying out one or more blank cuts, in which the knife (3) is moved along a direction substantially parallel to the rotational axis (R) of the knife (3) from a slicing position (AS) configured for slicing the at least one product caliber (K) into slices (S) to a blank cutting position (LS).in which, during each rotation of the knife (3) about the axis of rotation (R), no slice (S) of the at least one product caliber (K) is cut off, characterized in that the cutting unit (7) is designed and intended to perform a retraction movement (B) of the knife (3) from the empty cutting position (LS) to the cutting position (AS) after the execution of one or more blank cuts, wherein the knife (3) performs a movement about the axis of rotation (R) during the retraction movement (B) which corresponds to more than one complete revolution of the knife (3) about the axis of rotation (R), and that the cutting unit (7) is configured to perform the disengagement movement (A) with an acceleration (a) and / or a velocity (V) which has / have a higher value than an acceleration (a) and / or a velocity (V) of the retraction movement (B).

Description

[0001] The invention relates to a slicing machine, in particular a slicer, for slicing foodstuffs, comprising a feeding unit configured to feed at least one product caliber along a feeding direction, and a cutting unit configured to slice the at least one product caliber, wherein the cutting unit comprises a knife which can be driven to rotate about a rotational axis, and wherein the cutting unit is designed and intended to perform a disengagement movement for carrying out one or more blank cuts, in which the knife is moved along a direction substantially parallel to the rotational axis of the knife from a slicing position configured for slicing the at least one product caliber into slices to a blank cutting position.in which, during each rotation of the knife around the axis of rotation, no slice of at least one product caliber is cut off.

[0002] It should be noted at this point that the slicing machine according to the invention is designed to slice foodstuffs in the form of so-called product calibers, from which preferably shingled and / or stacked portions can be formed. The product calibers can be made, for example, from sausage, cheese, whole meat, pressed meat, and the like. The feeding unit can be designed, for example, as an endlessly circulating belt conveyor or the like. Preferably, the cutting unit is arranged downstream of the feeding unit with respect to the feeding direction. By means of the knife, which is mounted on the cutting unit, the slices can be cut from one end of a respective product caliber facing the cutting unit.

[0003] Furthermore, the product calibers are preferably fed to the feeding unit by means of a downwardly inclined feeder in the direction of the cutting unit's blade, so that the slices are already inclined when cut and can fall onto a discharge conveyor of the slicing machine's discharge unit, by which the slices can be conveyed for further processing. Accordingly, the blade can also be arranged with its cutting plane inclined to the vertical direction and overhanging forward in the feeding direction.

[0004] The product calibers are typically sliced ​​into portions using a slicing machine, each portion potentially consisting of several slices. After a portion has been completely sliced, one or more blank cuts are usually performed to allow the discharge unit sufficient time to convey the finished portion along a discharge path. A blank cut is defined as a situation where, during each rotation of the blade around its axis of rotation, no slice is cut from the at least one product caliber. This is achieved by the cutting unit, particularly the blade, disengaging into the blank cut position, in which no slices are cut from the at least one product caliber despite the blade's rotation around its axis.

[0005] After a desired number of blank cuts have been made, the knife must be moved back from the blank cut position to the cutting position along the direction that is essentially parallel to the axis of rotation of the knife, which corresponds to a retraction movement of the knife.

[0006] All of this also applies to the slicing machine according to the invention.

[0007] The disengagement and retraction movements of known slicing machines are usually carried out relatively quickly, for example within a maximum of one blade revolution or less, because otherwise so-called snippet formation can occur, in which misshapen or unusable slices or partial slices are cut from the product caliber.

[0008] As mentioned earlier, the knife, with its cutting plane, is usually inclined relative to a vertical direction and overhangs forward in the feed direction. Therefore, depending on the angle of inclination of the cutting plane, the force of gravity acting on the cutting unit, and especially on the knife, must be at least partially overcome during the engagement movement. This can lead to high accelerations and / or speeds, particularly during engagement, and thus to considerable stress and / or increased wear on the idle drive unit of the cutting unit, which is designed to effect the engagement and, preferably, also the disengagement movement. This effect can be further intensified by particularly high knife speeds of up to 1000 rpm and more, as the engagement and disengagement movements must be performed correspondingly faster.

[0009] It is therefore an object of the invention to remedy this, in particular by providing a slicing machine which has the lowest possible susceptibility to wear and / or maintenance and is suitable for minimizing the risk of chip formation during blank cutting.

[0010] This problem is solved according to the invention by a slicing machine of the type mentioned at the outset, in which the cutting unit is designed and intended to perform a retraction movement of the knife from the empty cutting position to the slicing position after the execution of one or more blank cuts, wherein the knife performs a movement around the axis of rotation during the retraction movement which corresponds to more than one complete revolution of the knife around the axis of rotation.

[0011] In other words, according to the invention, the engagement movement of the knife from the idle cutting position to the slicing position extends, particularly in terms of time, over more than one knife revolution, thus providing more time for the engagement movement. This is especially gentle on the idle cutting drive unit of the cutting unit. As a result, the engagement speed and / or acceleration required for the engagement movement can be significantly reduced, leading to less wear and thus improved ease of maintenance of the entire slicing machine. Accordingly, the engagement movement can also be described as a "soft engagement" according to the invention.

[0012] Preferably, the knife is moved substantially in the feed direction during the disengagement movement and / or is moved substantially against the feed direction during the engagement movement.

[0013] According to a preferred embodiment, it is proposed that the movement of the knife about the axis of rotation during the engagement movement corresponds to a plurality of complete revolutions, preferably two complete revolutions, of the knife about the axis of rotation. In other words, the engagement movement of the knife can extend over a rotation of the knife through an angle of several complete revolutions, preferably approximately or exactly 720°, about the axis of rotation. To further reduce the engagement speed and / or the engagement acceleration, the engagement movement can extend over more than two revolutions or more than 720°, provided that this does not undesirably prolong the engagement process of the knife.

[0014] Furthermore, it is proposed that the start of the engagement movement essentially corresponds to the cutting start angular position of the knife around the axis of rotation, where the cutting start angular position corresponds to the angular position of the knife around the axis of rotation at which the knife, in particular a cutting edge of the knife, first engages with the product caliber when slicing a respective slice in the slicing position. If the engagement movement extends, for example, over two or more revolutions, the engagement movement is then ideally completed immediately before or at the point in time when the knife again reaches the cutting start angular position in order to slice another slice of the product caliber.Consequently, the infeed movement can be started as early as possible, thus maximizing the available time without increasing the risk of chip formation, since the infeed movement is completed before or at least at the beginning of cutting the next slice of the product caliber.

[0015] Additionally or alternatively, the disengagement movement can essentially begin at the cutting-end rotational position of the blade around the axis of rotation. This cutting-end rotational position can correspond to the angle at which the blade, after cutting a slice, is no longer engaged with the product caliber. The disengagement movement preferably begins immediately at the cutting-end rotational position to utilize the maximum rotational range of the blade for the disengagement movement. Consequently, the disengagement movement can be initiated as early as possible, thus maximizing the available time without increasing the risk of chip formation.

[0016] According to a preferred embodiment, it is proposed that the engagement stroke of the engagement movement against the feed direction and / or the disengagement stroke of the disengagement movement in the feed direction be / are greater in magnitude than a minimum stroke required to prevent the knife from engaging with the product caliber in the idle cutting position, wherein the engagement stroke and / or the disengagement stroke preferably correspond to at least approximately twice the minimum stroke. Consequently, even after completion of part of the engagement movement, undesired contact between the knife and the product caliber, i.e., the formation of chips, does not occur, even if the engagement movement extends over several knife revolutions around the axis of rotation.If the engagement movement extends over, for example, two knife rotations, it can be divided into two partial movements opposite the feed direction, with each partial movement corresponding to the minimum stroke. Preferably, however, the two partial movements transition seamlessly into one another, meaning the knife can move continuously, i.e., without interruption, from the idle cutting position to the cutting position. The minimum stroke required for an idle cut can also be referred to as the idle cutting path.

[0017] Furthermore, the cutting unit can be configured to perform the disengagement movement with an acceleration and / or speed that is higher than the acceleration and / or speed of the engagement movement. Especially with a blade inclined vertically, the disengagement movement can still be performed faster than the engagement movement without causing excessively high stress on the cutting unit, particularly the idle drive unit, because the disengagement movement can have a directional component that extends essentially parallel to or in the direction of gravity. A rapid disengagement movement can further prevent the formation of wood chips.

[0018] To prevent a section of the product caliber projecting into or beyond the cutting plane in the feed direction from being cut off during the disengagement movement, a further embodiment proposes that the cutting unit be configured to perform at least part of the disengagement movement, preferably only part, within a clearance angle of the blade. In this clearance angle, the blade, when in the cutting position and rotating about the axis of rotation, does not engage with the product caliber. Accordingly, at least part of the disengagement movement, particularly the minimum stroke, is preferably performed only within the clearance angle to further prevent the formation of snippets.

[0019] According to a particularly preferred embodiment, the knife can be designed as a sickle-shaped knife, wherein the sickle-shaped knife preferably has a radius that is variable, and in particular increasing, in the circumferential direction around the axis of rotation. If the knife is designed as a sickle-shaped knife, the aforementioned cutting start angular position can correspond to an angular position of the sickle-shaped knife about the axis of rotation at which the sickle-shaped knife first engages with the product caliber when a slice is being cut. Conversely, the cutting end angular position can correspond to an angular position of the sickle-shaped knife about the axis of rotation at which, after a slice has been cut, the sickle-shaped knife no longer engages with the product caliber in the cutting position.Between the cutting end rotation angle position and the cutting start rotation angle position, there may be a clearance angle range in which the sickle blade does not engage with the product caliber, even in the cutting position, when rotating around the axis of rotation.

[0020] Furthermore, the disengagement and / or engagement movement can have a stroke in the feed direction in a range of, in particular, more than, 0 mm to 10 mm, preferably from 3 mm to 5 mm. Since the blade moves more than one complete revolution around the axis of rotation during the engagement movement, and thus more time is available for the engagement movement, the stroke can be correspondingly larger for the engagement movement without placing an excessive load on the idle drive unit of the cutting unit. With a constant stroke, the load, i.e., the acceleration or force acting on the idle drive unit, decreases accordingly.Since the disengagement movement preferably has a directional component parallel to the direction of gravity, it can generally be carried out at a higher speed and / or acceleration without causing disruptive loads on the idle drive unit, so that the stroke can also be chosen to be correspondingly large.

[0021] Since the disengagement movement preferably has a directional component pointing in the direction of gravity and / or parallel to gravity, it is further proposed that the cutting unit be configured to perform a movement about the axis of rotation during the disengagement movement of the blade, which corresponds, in particular, to at most one complete revolution of the blade about the axis of rotation. In contrast to the engagement movement, the disengagement movement can therefore extend over an angle of one revolution about the axis of rotation, which is in particular approximately or exactly 360°.

[0022] To perform the one or more blank cuts even more precisely and with the lowest risk of potential chip formation, according to a further embodiment, the feeding unit can also be configured to move the product caliber away from the cutting unit, in particular a cutting plane of the knife, in a retraction movement against the feeding direction during the execution of the one or more blank cuts. Consequently, during the execution of the one or more blank cuts, not only can the knife be moved away from the product caliber, but the product caliber itself can also be moved away from the knife.

[0023] It should also be added that the slicing machine may further comprise a gripper unit with at least one gripper which is designed to grip the at least one product caliber at its end facing away from the cutting unit.

[0024] Furthermore, the slicing machine can include a portioning unit in a manner known per se, which is configured to form portions from the slices cut by the slicing unit, wherein each portion can comprise one or more slices.

[0025] Additionally or alternatively, the slicing machine may also include a conveying unit which is designed to convey the slices cut by the cutting unit along a conveying direction in order to further process the slices and / or, in particular by means of a packaging device downstream of the slicing machine, to package them.

[0026] According to another aspect, the invention relates to a method for slicing food using a slicing machine, in particular according to the invention, comprising the following steps: Feeding, by means of a feeding unit of the slicing machine, at least one product caliber along a feeding direction, Slicing, by means of a cutting unit of the slicing machine, of at least one product caliber into slices, wherein a knife of the cutting unit is driven to rotate about a rotational axis, and Performing, by means of the cutting unit, a disengagement movement to carry out one or more blank cuts, wherein the knife is moved along a direction substantially parallel to the axis of rotation of the knife from a cutting position, which is set up for slicing the at least one product caliber into slices, to a blank cutting position, in which no slice is cut from the at least one product caliber during each rotation of the knife about the axis of rotation, wherein, after performing one or more blank cuts, the cutting unit performs a retraction movement of the knife from the blank cut position to the cutting position, wherein the knife performs a movement around the axis of rotation during the retraction movement which corresponds to more than one complete revolution of the knife around the axis of rotation.

[0027] With regard to the advantages and effects of the method according to the invention, reference is made to the advantages and effects of the slicing machine according to the invention, whereby all statements made in relation to the slicing machine also apply to the method and vice versa.

[0028] According to one embodiment, the movement of the knife during the engagement movement can correspond to a plurality of complete revolutions, preferably two complete revolutions, of the knife around the axis of rotation.

[0029] Furthermore, the disengagement movement can be performed with an acceleration and / or a velocity that is higher than the acceleration and / or velocity of the engagement movement.

[0030] The invention will be explained in more detail below with reference to the accompanying drawing and an exemplary embodiment. The drawing depicts: Fig. 1a an embodiment of a slicing machine according to the invention in perspective view, Fig. 1b the slicing machine according to Fig. 1a in side view, Fig. 2a one, starting from the Fig. 1a and Fig. 1b simplified, schematic side view of an embodiment of a slicing machine according to the invention, in which a knife of a cutting unit is in a slicing position, Fig. 2b the schematic side view according to Fig. 2a, in which the knife is in an empty cutting position, and Fig. 3 a schematic diagram to illustrate the execution of a disengagement movement and a subsequent retraction movement of the cutting unit of the slicing machine according to the invention.

[0031] The Fig. 1a and Fig. Figure 1b shows a slicing machine 1 according to an embodiment in the form of a multi-lane slicer 1 for simultaneously slicing several product calibers K on each of a lane SP1 to SP4 next to each other and depositing them in shingled portions P from several slices S with a general flow direction 10* through the slicer 1 from right to left.

[0032] Fig. Figure 1b shows a side view of slicer 1 with product caliber K inserted, omitting covers and other parts attached to a base frame 2, so that the functional parts, especially the conveyor belts, are more clearly visible. The longitudinal direction 10 is the feeding direction of the product calibers K to a cutting unit 7 and thus also the longitudinal direction of the product calibers K lying in slicer 1.

[0033] In this arrangement, several, in this case four, product calibers K lying side by side on a feeder 4, with projections 15 of the feeder 4 rising from a support surface as spacers between them, can be fed to a cutting unit 7 of the slicer 1 with a knife 3 rotating about a rotational axis R, for example a sickle knife 3, by a feeding unit 20, from whose front ends the rotating knife 3 with its cutting edge 3a can cut off a disc S with each revolution about the rotational axis R.

[0034] For cutting the product caliber K, the feeder 4 is located in the Fig. 1a shown, inclined cutting position with low-lying cutting-side front end and high-lying rear end, from which it can be folded down about a pivot axis running in its width direction, the first transverse direction 11, which is located near the cutting unit 7, into an approximately horizontal loading position, as shown in Fig. 1b is shown.

[0035] The rear end of each product caliber K located in the feed unit 20 is positively held by a gripper 14 or 14a-d by means of gripper claws 16. These grippers 14 or 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 moved along a gripper guide 18 in the feed direction 10.

[0036] In this system, both the feed of the gripper unit 13 and the feeder 4 can be driven in a controlled manner, but the specific feeding speed of the product calibers K can be achieved by a similarly controlled, so-called upper and lower product guide 8, 9, which engages the top and bottom of the product calibers K to be cut in their front end areas near the cutting unit 7.

[0037] The leading ends of the product calibers K are each guided through a product opening 6a-d of a plate-shaped cutting frame 5. The cutting plane 3" runs directly in front of the front, downward-sloping end face of the cutting frame 5. The knife 3 rotates within this plane with its cutting edge 3a around the axis of rotation R, thereby cutting off the excess product caliber K from the cutting frame 5 as a disc S. The cutting plane 3" runs orthogonally to the upper run of the feeder 4 and / or is spanned by the two transverse directions 11, 12 to the feed direction 10. The inner circumference of the product openings 6a-d serves as the counter-edge for the cutting edge 3a of the knife 3.

[0038] Since both product guides 8, 9 can be driven in a controlled manner, in particular independently of each other and / or possibly separately for each track SP1 to SP4, these determine a - continuous or clocked - feed rate of the product calibers K through the cutting frame 5.

[0039] The upper product guide 8 is displaceable in the second transverse direction 12, which runs orthogonally to the surface of the upper run of the feeder 4, to adapt to a height of the product caliber K in this direction. Furthermore, at least one of the product guides 8, 9 can be designed to pivot about one of its deflection rollers in order to be able to change the direction of a guide belt of the product guide 8 and / or 9 that rests against the respective product caliber K to a limited extent.

[0040] The discs S, which are positioned at an angle in space during separation, fall onto a conveying unit 17 that begins below the cutting frame 5 and extends in the direction of flow 10*, and which in the illustrated embodiment comprises several conveying units 17a, 17b, 17c arranged one behind the other in the direction of flow 10*, of which the first conveying unit 17a in the direction of flow 10 can be designed as a weighing unit 17a and in particular also as a portioning belt.

[0041] The slices S can hit the conveying unit 17 individually and spaced 10* apart from each other in the direction of travel, or, by appropriate control of the weighing unit 17a, whose movement, like almost all moving parts, is controlled by a control unit 1* of the slicer 1, shingled or stacked portions P can be produced (see Fig. 1b) are formed. The portions P can be formed, for example, by a stepwise forward movement of the P of the weighing unit 17a, which in this case also serves as a portioning belt, in the direction of travel 10*.

[0042] In the illustrated embodiment, below the feed unit 20 there is a substantially horizontal residual conveyor 21, which begins with its front end below the cutting frame 5 and directly below or behind the discharge unit 17 and can transport residual material falling onto it to the rear with its upper run.

[0043] In Fig. 2a is one, starting from the Fig. 1a and Fig. Figure 1b shows a highly simplified, schematic side view of a slicing machine 1 according to the invention. The slicing machine 1 can be described in terms of its operating principle as described above with reference to the Fig. 1a and Fig. The slicing machine 1 described in 1b corresponds to the feed unit 20 with the feeder 4, the knife 3 of the cutting unit 7 and the control unit 1* as well as the upper product guide 8, the lower product guide 9 and the gripper 14 are shown in this diagram. Fig. 2a is shown only schematically. Furthermore, in Fig. 2a The conveyor 17a described above is shown schematically, which can be designed as a portioning belt for the discs S.

[0044] In Fig. 2a shows the knife 3 in a cutting position AS, which is set up for cutting the product caliber K into slices S.

[0045] In Fig. In 2b, however, the knife 3 is shown in an empty cutting position LS, with the knife 3 starting from Fig. 2a has been moved away from the product caliber K by a predetermined amount, essentially parallel to the feed direction 10. In the idle cutting position of the knife 3, no disc S is cut from the at least one product caliber K during each rotation of the knife 3 about the axis of rotation R. To effect a disengagement movement of the knife 3 from the in Fig. 2a shown cutting position into the in Fig. 2b shown empty cutting position and / or a retraction movement of the knife 3 from the in Fig. 2b shown empty section position in the in Fig. In the cutting position shown in 2a, the cutting unit 7 may further comprise an idle cutting drive unit (not shown) which is configured to displace the knife 3 substantially parallel to the feed direction 10 and in the opposite direction thereto.

[0046] Optionally, the feed unit 20 can also be configured to move the product caliber K essentially against the feed direction 10 away from the knife 3 in order to carry out one or more blank cuts, in order to better avoid the occurrence of possible chip formation during blank cuts.

[0047] In Fig. Figure 3 schematically illustrates the execution of a disengagement movement A and a subsequent retraction movement B of the knife 3 using corresponding graphs, where the graph r(t) shows the time course of the radius r of the knife 3 at a reference position, in particular a fixed position, on the slicing machine 1. The reference position can be located in the area of ​​the cutting frame 5 (see Figure 3). Fig. 1a and Fig. 1b) of the slicing machine 1. Since the knife 3 is depicted as a sickle-shaped knife according to the illustrated embodiment, the radius acting at the reference position has a sawtooth-like profile, whereby the radius increases linearly over time t up to a maximum radius r0 and then drops abruptly to a base radius r0, which can correspond to a minimum radius of the knife 3. It should be noted that the in Fig. The sawtooth-like curve shown in Figure 3 is merely schematic and the actual curve of the radius of the sickle blade 3 may differ from the curve shown.

[0048] Furthermore, in Fig. 3. Furthermore, the position P of the cutting blade 3 is shown as a function of time. The zero line of the curve P(t) can correspond to the cutting position AS of the blade 3, which, for example, in Fig. Figure 2a illustrates this. Starting from the cutting position AS, the knife 3 can be moved by one disengagement stroke in the feed direction 10 to the idle cutting position LS, whereby the disengagement stroke required for this in the feed direction 10 can be twice the minimum stroke H. In the illustrated embodiment, the minimum stroke H is the stroke required to prevent the knife 3 from engaging with the product caliber K during one complete rotation of the knife 3 about the axis of rotation R.

[0049] The graph V(t) accordingly shows the velocity V of the knife 3 as a function of time t and represents the time derivative of the graph P(t). The graph a(t) finally shows the acceleration a of the knife 3 as a function of time t, where the graph a(t) can therefore correspond to the time derivative of the graph V(t).

[0050] As further in Fig. As can be seen in the illustrated embodiment, the disengagement movement A of the knife 3 from the cutting position AS to the idle cutting position LS begins at a cutting end rotational angular position SE of the knife 3, wherein the cutting end rotational angular position SE of the knife 3 can correspond to a rotational angular position of the knife 3 about the axis of rotation R at which the knife 3, after cutting a respective disc S in the cutting position AS, no longer engages with the product caliber K for the first time. It can be seen that the knife 3 reaches the minimum stroke H approximately, preferably exactly, upon reaching a cutting start rotational angular position SB of the knife 3, wherein the cutting start rotational angular position SB can correspond to a rotational angular position of the knife 3 about the axis of rotation R at which the knife 3, after cutting a respective disc S in the cutting position AS, first engages with the product caliber K.In other words, a respective rotation angle range of the knife 3 is described between a respective cutting start rotation angle position SB and a respective cutting end rotation angle position SE in . Fig. 3 a cutting angle range SW in which the knife 3 engages with the product caliber K. The angle range between a respective cutting end rotation angle position SE and a respective cutting start rotation angle position SB, on the other hand, corresponds to a clearance angle range FW in which the knife 3, in the cutting position, does not engage with the product caliber K when rotating about the axis of rotation R.

[0051] As also in Fig. As can be seen in Figure 3, in the present embodiment, the disengagement movement A extends from the cutting position AS to the idle cutting position LS over an angle of 360°, while the engagement movement B extends from the idle cutting position LS to the cutting position AS over an angle of twice 360°, i.e., a total of 720°, which corresponds to two complete rotations of the knife 3 around the axis of rotation R. Since the engagement movement B extends over an angular range and / or time period that is twice as large as the angular range or twice as long as the time period of the disengagement movement A, the knife 3 exhibits a correspondingly significantly lower speed V or acceleration a during the engagement movement B, which can lead to correspondingly lower loads on components of the slicing machine 1, in particular the idle cutting drive unit of the knife 3 and / or other components of the cutting unit 7.

[0052] As further in Fig. As can be seen, the engagement movement B begins at a cutting start SB, which means that after completion of the engagement movement B, which in this case corresponds to two complete rotations of the knife 3, the knife 3 is again in or immediately before the cutting start rotational position SB, so that cutting a new disc S can begin immediately.

[0053] It should also be added that, after the knife 3 has performed the simple minimum stroke H starting from the empty cutting position LS (see graph P(t)), the knife 3 is in a central position MS, in which the knife 3 is still a further minimum stroke H away from the cutting position AS, so that there is no contact between the knife 3 and the product caliber K and thus no undesirable chip formation even if the knife 3 passes through the cutting start rotation angle position SB again in the central position MS.

Claims

[1] Slicing machine (1), in particular slicer, for slicing food, comprising: a feeding unit (20) which is configured to feed at least one product caliber (K) along a feeding direction (10), and a cutting unit (7) which is configured to cut the at least one product caliber (K) into slices (S), wherein the cutting unit (7) comprises a knife (3) which is rotatable about a rotational axis (R), and wherein the cutting unit (7) is designed and intended to perform a disengagement movement (A) for the purpose of carrying out one or more blank cuts, in which the knife (3) is moved along a direction substantially parallel to the axis of rotation (R) of the knife (3) from a cutting position (AS), which is set up for cutting the at least one product caliber (K) into slices (S), to a blank cutting position (LS), in which no slice (S) is cut from the at least one product caliber (K) during each rotation of the knife (3) about the axis of rotation (R), characterized by , that the cutting unit (7) is designed and intended to perform a retraction movement (B) of the knife (3) from the empty cutting position (LS) to the cutting position (AS) after the execution of one or more blank cuts, wherein the knife (3) performs a movement around the axis of rotation (R) during the retraction movement (B) which corresponds to more than one complete revolution of the knife (3) around the axis of rotation (R). [2] Slicing machine according to claim 1, characterized by , that the movement of the knife (3) about the axis of rotation (R) during the engagement movement (B) corresponds to a plurality of complete revolutions, preferably two complete revolutions, of the knife (3) about the axis of rotation (R). [3] Slicing machine according to claim 1 or 2, characterized by, that a start of the engagement movement (B) essentially corresponds to a cutting start rotational angular position (SB) of the knife (3) about the axis of rotation (R), wherein the cutting start rotational angular position (SB) corresponds to a rotational angular position of the knife (3) about the axis of rotation (R), at which the knife (3), in particular a cutting edge (3a) of the knife (3), engages with the product caliber (K) for the first time when cutting a respective disc (S) in the cutting position (AS). [4] Slicing machine according to any one of the preceding claims, characterized by, that a start of the disengagement movement (A) essentially corresponds to a cutting rotation angle position (SE) of the knife (3) about the rotation axis (R), wherein the cutting rotation angle position corresponds to a rotation angle position of the knife (3) about the rotation axis (R) in which the knife (3) no longer engages with the product caliber (K) for the first time after cutting a respective disc (S) in the cutting position (AS). [5] Slicing machine according to any one of the preceding claims, characterized by , that an engagement stroke of the engagement movement (B) against the feed direction (10) and / or an engagement stroke of the disengagement movement in the feed direction (10) is / are greater in magnitude than a minimum stroke (H) required to prevent the knife (3) from engaging with the product caliber (K) in the idle cutting position (LS), wherein the engagement stroke and / or the disengagement stroke preferably corresponds to at least approximately twice the minimum stroke (H). [6] Slicing machine according to any one of the preceding claims, characterized by , that the cutting unit (7) is configured to perform the disengagement movement (A) with an acceleration (a) and / or a velocity (V) which is / are greater than the acceleration (a) and / or velocity (V) of the engagement movement (B). [7] Slicing machine according to any one of the preceding claims, characterized by , that the cutting unit (7) is configured to perform at least part of the disengagement movement (A), preferably only, within a clearance angle range (FW) of the knife (3) in which the knife (3) in the cutting position (AS) does not engage with the product caliber (K) when rotating about the axis of rotation (R). [8] Slicing machine according to any one of the preceding claims, characterized by, that the knife (3) is designed as a sickle knife, wherein the sickle knife preferably has a radius (r) that is variable in the circumferential direction around the axis of rotation (R), in particular increasing. [9] Slicing machine according to any one of the preceding claims, characterized by , that the disengagement movement (A) and / or the engagement movement (B) has a stroke in the feed direction (10) in a range of, in particular more than, 0 mm to 10 mm, preferably from 3 mm to 5 mm. [10] Slicing machine according to any one of the preceding claims, characterized by , that the cutting unit (7) is designed to perform a movement around the axis of rotation (R) during the disengagement movement (A) of the knife (3), which corresponds, in particular, at most to a complete revolution of the knife (3) around the axis of rotation (R). [11] Slicing machine according to any one of the preceding claims, characterized by, that the feed unit (20) is further equipped to move the product caliber (K) away from the cutting unit (7), in particular a cutting plane (3") of the knife (3), during the execution of one or more blank cuts, to perform a retraction movement against the feed direction (10). [12] Method for slicing foodstuffs using a slicing machine (1), in particular according to one of the preceding claims, comprising the following steps: Feeding, by means of a feeding unit (20) of the slicing machine (1), at least one product caliber (K) along a feeding direction (10), and Slicing, by means of a cutting unit (7) of the slicing machine (1), of the at least one product caliber (K) into slices (S), wherein a knife (3) of the cutting unit (7) is driven to rotate about a rotational axis (R), and Performing, by means of the cutting unit (7), a disengagement movement (A) to carry out one or more blank cuts, wherein the knife (3) is moved along a direction substantially parallel to the axis of rotation (R) of the knife (3) from a cutting position (AS), which is set up for cutting the at least one product caliber (K) into slices (S), to a blank cutting position (LS), in which no slice (S) is cut from the at least one product caliber (K) during each rotation of the knife (3) about the axis of rotation (R), characterized by , that, after performing one or more blank cuts, the cutting unit (7) performs a retraction movement (B) of the knife (3) from the blank cut position (LS) to the cutting position (AS), wherein the knife (3) performs a movement around the axis of rotation (R) during the retraction movement (B) which corresponds to more than one complete revolution of the knife (3) around the axis of rotation (R). [13] Method according to claim 12, characterized by , that the movement of the knife (3) during the engagement movement (B) corresponds to a plurality of complete rotations, preferably two complete rotations, of the knife (3) around the axis of rotation (R). [14] Method according to claim 12 or 13, characterized by , that the disengagement movement (A) is performed with an acceleration (a) and / or a velocity (V) which is / are higher than the acceleration (a) and / or velocity (V) of the engagement movement (B).