Cutting unit and slicing machine with such a cutting unit

Abstract

Cutting unit (2) with - a rotating knife (3) that is circular when viewed in the direction of the knife axis (3') and bowl-shaped in cross-section, - whose outer circumferential edge is designed as a circumferential cutting edge (3a) which defines a knife plane (3"), - whose knife axis (3') can be displaced during the cutting process, - wherein the knife axis (3') is mounted in a knife carrier (2a), characterized in that, viewed from the knife axis (3') in the circumferential direction at least in the immersion area (20) - on the concave inner side (3.1) of the bowl-shaped knife (3) an inner, fixed, i.e. not rotating with the knife (3), inner cover (17) is arranged, which at least partially covers the concave interior (7) of the knife (3), and - on the convex outer side (3.2) of the bowl-shaped knife (3) an outer, fixed outer cover (18) is arranged, which does not rotate with the knife (3) and at least partially covers the outer side (3.2) of the knife (3) and whose radial outer edge (18a) is offset radially inwards from the cutting edge (3a).

Description

I. Area of ​​application

[0001] The invention relates to slicing a product, for example a food product, which can behave elastically and / or plastically, for example an irregularly shaped product such as a naturally grown piece of meat. II. Technical Background

[0002] A cutting unit for this purpose includes, for example, a rotating knife whose cutting edge can be moved into the product to be cut in the direction of immersion, usually perpendicular to the feed direction in which the piece of meat is pushed forward in order to gradually cut slices from its front end, so that the rotating knife can always be in the same position in the feed direction, the longitudinal direction.

[0003] Cutting can be done with a circular rotating knife, so that for the insertion the entire knife including its axis of rotation moves relative to the product, or with a non-circular knife such as a so-called sickle knife, in which only part of its circumferential contour is formed as a cutting edge, which has an increasing distance from the axis of rotation of the knife in its direction of travel.

[0004] For appropriate slicing machines, which are intended to slice irregularly shaped pieces of meat, the speed of slicing is important on the one hand, but also the quality of the sliced ​​pieces, for example constant thickness, clean, non-frayed edges and similar mostly optical parameters.

[0005] When slices of a predetermined weight are to be cut, adherence to the target weight is another quality parameter.

[0006] Especially when a target weight of the slices is to be achieved, irregularly shaped products, such as naturally grown pieces of meat, are fed to the cutting unit by first placing the irregularly shaped piece of meat into a forming tube with a cross-section that is constant along its length and open at the rear and front ends, and pressing it there at least in its longitudinal direction so that the irregularly shaped piece of meat becomes a strand with a cross-section that is essentially constant along its length, corresponding to the inner cross-section of the forming tube.

[0007] Using the longitudinal press ram, which can be moved inside the forming tube, the piece of meat is then pushed beyond the front end of the forming tube to a stop plate, and cut off immediately in front of the front end of the forming tube using the knife.

[0008] This can lead to a variety of problems, such as the knife sticking too strongly to the disc on the one hand and / or to the rest of the product on the other hand during the cutting process.

[0009] The disc sticking to the blade can cause it to not detach evenly and fall off the blade, resulting in a wavy or even a tumble onto the surface.

[0010] Furthermore, the friction between the knife and the product, due to the high speed of the knife, can lead to such intense heating of the product that undesirable changes, such as biochemical processes, can be initiated in a food product. This problem occurs particularly with circular knives – that is, knives with a circular cutting edge concentric to the knife's axis of rotation – because the contact time of the knife with the product during a cutting process is longer than with a sickle knife.

[0011] Document DE 34 27 116 A1 discloses a cutting unit according to the preamble of claim 1. Reference is also made to documents DE 10 2009 011 398 A1, DE 10 2017 113 667 A1, DE 10 2016 107 849 A1, DE 10 2017 112 178 A1, DE 12 65 362 A and DE 36 50 216 T2. III. Description of the invention a) Technical problem

[0012] The object of the invention is therefore to avoid the aforementioned disadvantages and to provide an improved cutting unit and a cutting machine equipped with it. b) Solution of the task

[0013] This problem is solved by the features of claims 1 and 13. Advantageous embodiments are described in the dependent claims.

[0014] In order to reduce the friction between the product and the disc based on the rotational speed of the knife, according to the invention the inside and outside of the knife are covered by a cover that does not rotate with the knife but is fixed with respect to the knife axis, so that only the immersion movement of the knife axis causes a relative movement and thus friction between the product and the corresponding cover: The cover must of course not cover the cutting edge of the knife or impair its function; therefore, its outer edge must end radially in front of the cutting edge of the rotating knife.

[0015] The outer edge of the cover is located at the smallest possible distance - possibly even without any distance - to the knife and / or in such a relative position to the knife that the ingress of contaminants between the knife and the cover is avoided as much as possible.

[0016] The cover must extend along the circumference around the knife axis, at least within the knife's immersion zone. This zone is defined as the area perpendicular to both the immersion and feed directions, covered by the one or more adjacent products, including the space between them. For example, in the case of a single forming tube, this would be the width of the tube. The maximum possible immersion zone is therefore the diameter of the rotating, circular-shaped knife.

[0017] Of course, the cover can extend over more than 180° around the axis of rotation of the knife, thus covering the corresponding side of the knife essentially completely, i.e. at least 90% or better at least 95%, but this is not absolutely necessary, since the knife only penetrates the product up to the knife axis. Inner cover:

[0018] Disc-shaped knives with a convex outer surface generally have a concave inner surface pointing towards the product and are therefore bowl-shaped knives, of which only the cutting edge and possibly a narrow area of ​​the back of the knife extending radially inwards to the cutting edge lies in the plane of the knife defined by the cutting edge.

[0019] An inner cover is then preferably arranged in the concave interior of the knife in such a way that its outer edge extends close to the outer edge of the concave interior at its opening, preferably being spaced only a maximum of 2 mm to 6 mm apart from it, and in particular being radially offset from it.

[0020] Since the concave interior space tapers radially outwards to a point, the cross-section of the inner cover is preferably also tapered to a point towards its outer edge.

[0021] In a preferred embodiment, the cover dips with its outer edge - which can also be tapered to a point - into an undercut located at the radially outer edge of the cross-section of the concave interior, which makes the penetration of meat fibers and other contaminants in between particularly difficult.

[0022] The inner cover should preferably not protrude axially beyond the blade plane, but should be flush with it or have an offset from it towards the outside of the blade, i.e. into the interior, preferably of 0.1 millimeters to 1.0 mm.

[0023] For the inner cover, the cover preferably covers the entire concave interior, as this is the easiest way to prevent dirt from entering the interior.

[0024] If the concave interior of the knife extends radially outwards to the cutting edge, then when the inner cover is brought up to the inner circumference of the opening of the concave interior, no area of ​​the inside of the knife remains that grinds against the product.

[0025] Since the knife, due to its size and necessary thickness, usually weighs several hundred grams, mostly over 1 kg, the fastening of the outer cover to the knife is designed in such a way that even after the outer cover is loosened, the knife is still securely held on the knife axis and cannot unintentionally fall off.

[0026] The fastening of the inner cover and the inner cover itself are preferably designed in such a way that the inner cover can be removed from the knife carrier for cleaning purposes without having to detach the knife from the knife carrier. Outer cover:

[0027] On the outer side of the knife facing the cut-off disc, which is usually convexly curved, there may be an outer cover which is preferably also convex on its outer side facing away from the knife and / or concave on its inner side facing the knife.

[0028] Preferably, the inner side of the outer cover facing the knife runs parallel to the outer side of the knife.

[0029] The outer cover preferably ends with its outer edge radially within the resharpening area of ​​the knife, so that even in a heavily worn and resharpened condition, the knife still protrudes radially beyond the outer cover with its cutting edge, in particular with its entire ground surface.

[0030] The cross-section of the outer cover should taper to a point at its outer edge, as the cut-off disc must be able to slide easily over this outer edge, the deflecting surface of the outer cover. This deflecting surface, adjoining the outer edge of the outer cover, is preferably straight in the axial section of the blade, with a defined deflection angle to the blade plane. This angle is chosen according to how strongly this area should push the cut-off disc away from the blade.

[0031] Accordingly, this deflection angle can be larger than the cutting angle of the knife, i.e., the angle between the grinding surface of the knife and the knife plane, or smaller or equal to it.

[0032] The cutting angle is usually between 20° and 25°.

[0033] To facilitate the sliding of the severed cutting edge onto the outside of the outer cover, the outer cover projects with its outer edge in a radial direction at most to the grinding surface; preferably, it ends at a radial distance from this inner edge of the grinding surface, which preferably corresponds to the maximum radial wear of the knife by resharpening or should be slightly greater.

[0034] Preferably, the outer cover is attached in a radially adjustable manner relative to the knife carrier, in order to always be able to adjust the distance between the outer edge of the outer cover and the cutting edge the same, even after resharpening.

[0035] The knife may have a ridge on its outer side that serves as a deflector for the cut-off slice.

[0036] In this case, the outer cover can extend as close as possible to this deflector with its outer edge, especially radially, but its outer edge should not protrude beyond this bead in the axial direction.

[0037] To make it more difficult for meat fibers or other contaminants to penetrate, the outer cover preferably dips into an annular groove arranged on the outside of the knife, so that the outer surface of the outer cover begins as close as possible to the inside of the annular groove, which further facilitates the sliding of the disc onto the outer cover.

[0038] Since the knife, due to its size and necessary thickness, usually weighs several hundred grams, often over 1 kg, and frequently several kilograms, the fastening of the outer cover on the knife is designed in such a way that even after the outer cover is loosened, the knife is still securely held on the knife axis and cannot unintentionally fall off.

[0039] For the outer cover, it is preferably chosen to extend only over the immersion area in order to keep the outer cover small in terms of volume and therefore weight.

[0040] Preferably, groove-shaped projections are arranged on the contact surface of the respective cover facing the disc or the rest of the product, extending in the direction of immersion of the knife axis into the product in order to further minimize friction with the cover.

[0041] As a rule, the knife is mounted in a rotating drive in a knife carrier, which is pivotably arranged on the knife base frame, either rotating or linearly oscillating.

[0042] The cover(s) are preferably mounted on the blade carrier and attached in a way that allows for quick and easy removal and installation, as the covers must be removed not only when changing the blade, but also for cleaning purposes during the use of the same blade. Preferably, a cover can be removed from and / or installed on the blade carrier without tools and / or in less than 20 seconds.

[0043] Preferably, the covers are made of plastic and are manufactured as injection-molded parts.

[0044] The cutting unit includes a knife drive that is capable of driving the knife for cutting at a minimum of 30 rpm, better at a minimum of 90 rpm, better at a minimum of 150 rpm, better at a minimum of 250 rpm, better at a minimum of 250 rpm.

[0045] Preferably, the knife should rotate at a maximum of 2000 rpm during cutting, better at a maximum of 1500 rpm, better at a maximum of 1000 rpm.

[0046] This relatively high rotational speed means that if the cover comes into contact with the blade, abrasion immediately occurs on the cover, which can accumulate on the product or the cut-off slices, something that should be completely avoided when using such a cutting unit in a commercial setting.

[0047] The cover should therefore be designed and attached in such a dimensionally stable manner that unintentional contact between the cover and the blade cannot occur during cutting operations. This is further complicated by the fact that the blade preferably has a diameter of at least 100 mm, more likely at least 200 mm, more likely at least 400 mm, more likely at least 600 mm.

[0048] To ensure that a cover with correspondingly large dimensions is stable despite its minimal weight, reliably preventing contact with the rotating blade, presents an additional challenge. If this cannot be guaranteed, a special contact area should be present on the blade, preferably running in the direction of rotation, and the material pairing between the cover and this contact area should be selected to prevent abrasion upon contact.

[0049] As a rule, the knife has a thickness of 0.5 mm to 1.5 mm at the radially inner end of its grinding surface, depending on the wear condition of the knife.

[0050] Preferably, however, the knife has a constant thickness in the regrinding area that extends radially inwards from the radially inner end of the grinding surface, for example between 0.5 and 2.0 mm.

[0051] With regard to the knife, this has the advantage that, regardless of the wear condition, the grinding surface always has the same radial width.

[0052] Regarding the outer cover, this has the advantage that it can be designed to be radially adjustable, so that with increasing resharpening, the outer cover can be moved further and further inwards relative to the blade, i.e., towards the blade axis, and thus, regardless of the wear condition, the outer cover always maintains the same radial distance to the cutting edge. Accordingly, the outer cover is preferably attached to the blade carrier in a way that allows for radial adjustment.

[0053] The slicing machine has a product support and a cutting unit according to the invention with a knife that is movable transversely to the feed direction of the product on the product support, wherein the direction of movement of the knife axis of the knife during slicing runs at an angle of a maximum of 90°, preferably a maximum of 70°, preferably a maximum of 45° to the vertical.

[0054] This causes the increasingly detached slice to tip over towards a storage surface and thus away from the knife, purely due to gravity.

[0055] Preferably, the feed direction of the product during cutting is at an angle of no more than 90°, better no more than 70°, better no more than 45° to the horizontal, whereby the direction of movement of the knife axis is usually perpendicular to the feed direction of the product.

[0056] This has proven to be the best angle for neatly placing the product on a storage surface, which can also be a conveyor.

[0057] The product support preferably also includes a product pushing device, in particular a product pusher, which applies a preload force of at least 1 N, preferably at least 3 N, to the product during cutting and presses it against a product stop.

[0058] Especially when slicing whole pieces of meat, the product holder does not just provide a simple support surface for the product, but rather a shaped tube consisting of one or more circumferential segments that completely encloses the product transversely to the feed direction.

[0059] In this process, the irregularly shaped piece of meat can be pressed into a strand or caliber with a consistent cross-section along its length using at least one longitudinal press die. This die is movable within the forming tube in its longitudinal direction and, when the product is sliced, also acts as a product pusher, advancing the strand-shaped product by the thickness of a slice at a time. This allows for the production of slices with a predetermined target weight.

[0060] Since the preload force also acts on the inner cover when the product comes into contact with it, the inner cover must be particularly stable or supported by the knife.

[0061] When operating such a cutting machine, the inner cover seals the cutting-side, i.e., knife-side, opening of the forming tube at the end of the cutting process in a liquid-tight manner to prevent the product from oozing out before the next cutting.

[0062] If the inner cover does not completely cover the knife-side opening of the form tube, but only together with the knife, this knife-side opening will be completely covered at least up to the radial distance between the cutting edge of the knife and the radially outer edge of the inner cover.

[0063] Preferably, the product slide, designed as a longitudinal press ram, also seals the cross-section of the mold tube behind the product inside in a liquid-tight manner to prevent the product, which may behave partially like a liquid or contain liquid, from oozing out between the press ram and the mold tube. c) Examples of implementation

[0064] Embodiments according to the invention are described in more detail below by way of example. The figures show: Fig. 1: A slicing machine with a circular blade in a side view, Fig. 2: the slicing machine according to Fig. 1 viewed in the longitudinal pressing direction from the cutting end of the forming tube, Fig. 3: a radial cut through a first design of the knife from the slicing machine according to the Fig. 1 and Fig. 2, Fig. 3a: a detailed enlargement from Fig. 3, Fig. 3b: a detailed enlargement from Fig. 3a when separating a slice, Fig. 4a-d: Axial sections through the outer edge areas of various knives, partly during the cutting of a slice.

[0065] The Fig. 1 and Fig. Figure 2 shows a cutting machine 1 according to the state of the art, wherein in the front view according to the Fig. 2 already shows the inventive design of the knife 3, the cross-section of which can be determined by means of the Fig. 3 - 3c will be explained in more detail.

[0066] The slicing machine 1 according to the Fig. 1, Fig. 2 has, on the one hand, in addition to the base frame 8 of the machine, a cutting unit 2, which includes the rotating knife 3 as knife unit 13, and a product support 12' directed diagonally downwards towards the knife 3, on which the product P to be cut rests and is pushed downwards in stages to be cut into slices S.

[0067] In this case, the product support 12' is not a simple support surface, but a fully enclosed form tube 12, which is open on both sides at the end face, and in which the product P is not only pushed forward for cutting by a longitudinal press punch 14, but can also be pressed longitudinally beforehand by this longitudinal press punch 14 so that the product P has a uniform cross-section over its length by conforming to the inner circumference of the form tube cavity 15.

[0068] The stop plate 16 can serve as a stop in the longitudinal pressing direction 10 for pressing, which is adjustable for cutting off the discs S to a specific thickness setting d in the form of a distance in the longitudinal pressing direction 10 to the front end, the cutting end 12a, of the form tube 12.

[0069] The stop plate 16 can also be used as a longitudinal stop when pressing the product P by directly placing it against the front end face of the form tube 12, since the stop plate 16 has a size that can completely cover the cross-section of the form tube cavity 15 at the cutting end 12a.

[0070] The stop plate 16 can be attached to the knife carrier 2a and thus usually moves synchronously with the knife axis 3'.

[0071] According to the Fig. 1, Fig. 2 The circular disc-shaped knife 3 only comes out of the overlap with the form tube cavity 15 if the entire knife 3 including the knife axis 3' is moved oscillating in the penetration direction 9 so far in the direction of the form tube 12 that the form tube cavity 15 is completely within the flight circle 3* as well as the actual knife 3.

[0072] The latter is particularly important if the knife is a circular segment-shaped knife rather than a circular disc-shaped knife, where the cutting edge 3a, which lies concentric to the knife axis 3', extends only over a part of the circumference of the knife 3.

[0073] In the Fig. 1 and Fig. Figure 2 shows a cutting machine 1 with two parallel adjacent mold tube cavities 15, here formed in a single mold tube 12, wherein the knife 3 cuts off a slice S from each of the two products P located in the two mold tube cavities 15 during a cutting operation by having a correspondingly large diameter or flight circle.

[0074] It can be seen that the diameter 3D of the knife 3 - which is also its flight circle 3* - and also the correspondingly smaller diameter 18D of the outer cover 18 are each larger than the immersion area 20 of the knife, which in these two adjacent shaped tubes extends from the left edge of the left shaped tube to the right edge of the right shaped tube.

[0075] In contrast to the representation of Fig. 2. A stronger immersion of the knife unit would cause both discs S to be separated to be placed with their entire width against the surface in the Fig. 2 visible outer surface 18.2 of the outer cover 18 run up.

[0076] Inventive designs of the knife unit, i.e. the knife 3 and its attachments, are described in the Fig. 3 - 3b as well as the Fig. Figures 4a - d show an axial section along the knife axis 3' at different magnifications through the knife 3 and especially its radial edge region:

[0077] The Fig. Figure 3 shows a typical circular disc-shaped knife 3, as is also found in the Fig. 1 and Fig. 2 is used in an axial section that passes through the knife axis 3'.

[0078] In Fig. 3 is the bowl-shaped knife 3 shown alone with the central opening for attachment to the knife axis 3' and a convexly curved outer surface 3.2, which is created by the fact that a connecting surface 5 adjoins the circumferential edge 3a, which is sharply ground as the cutting edge 3a, in this axial section view along the knife axis 3', to which the radially more inwardly located main part of the outer surface 3.2 adjoins, which runs parallel to the knife plane 3" which is defined by the circumferential cutting edge 3a.

[0079] In the inner side 3.1 of the knife, which is opposite the outer side 3.2, a concave recess is formed - in this case centered on the knife axis 3' - which has an interior 7 that is open to the knife plane 3" and extends over most of this side of the knife 3 in a radial direction, but not quite to the cutting edge 3a.

[0080] The detailed magnification of the edge area of ​​this axial section according to Fig. 3a shows, firstly, that when viewed in detail, the radial outer edge of the knife 3 is not immediately followed by a connecting surface 5, but first by a grinding surface 4, which runs at a cutting angle α to the knife plane 3".

[0081] This grinding surface 4 - which of course also surrounds the knife axis 3' - is the surface on which the grinding tool rests during resharpening and causes material removal on the grinding surface 4.

[0082] The connection surface 5 mentioned above only adjoins the radially inner edge of the ground surface 4.

[0083] Additionally, this magnification includes the Fig. 3a shows an inner cover 17 and an outer cover 18 according to the invention, which are preferably attached to the knife carrier 2 and do not rotate with the knife 3 around the knife axis 3'.

[0084] The inner cover 17 essentially fills the concave interior 7 on the inside 3.1 of the knife 3, at least in axial section along the knife axis 3', by extending with its radial outer edge 17a to near the radial outer edge 7a of the interior 7.

[0085] This is achieved by the inner cover 17 tapering to a point at its radially outer edge in the sectional view of the Fig. 3a, as well as interior 7.

[0086] Preferably, the inner cover 17 also has a thickness that is only slightly less than the axial depth of the interior 7.

[0087] In the present example, the outer surface 17.2 of the inner cover 17, facing away from the knife 3, is aligned with the knife plane 3", but can also be offset in axial direction 10 towards the knife 3.

[0088] In this case, the outer cover 18 has a constant thickness in the radial direction up to its outermost edge area, the deflecting surface 18.2a, and extends in the radial direction at a constant distance to the outer surface 3.2 of the knife 3.

[0089] However, this is by no means a condition for the realization of the invention, because the decisive factor is above all the deflecting surface 18.2a, which is part of the outer surface 18.2 of the outer cover 18 and adjoins its outer edge 18a radially inwards: Because, as can be seen in further magnification, Fig. As can be seen in Figure 3b, which also indicates the separation of a disc S from the product P, the deflecting surface 18.2a is at a deflection angle β to the knife plane 3" and can therefore be used to push the disc S away from the knife plane 3".

[0090] To prevent the disc S from getting stuck on the outer edge 18a of the outer cover 18, this is set back inwards relative to the radial extension of the grinding surface 4.

[0091] If the deflection angle β is identical to the cutting angle α of the grinding surface 4, the disc will at most come into contact with the radially inner area of ​​the deflection surface 18.2a of the outer cover 18, depending on its radial position and the radial length of this deflection surface 18.2a.

[0092] However, the deflection angle β can also be larger than the cutting angle α, and thereby significantly increase the deflection effect on the disc S, for which the deflection surface 18.2a can be made much longer in the radial direction with respect to the knife axis 3' than is required by the thickness of the outer cover 18, which provides sufficient stability.

[0093] Then the outer cover 18 can also have a different thickness in its radial direction.

[0094] The Fig. Figures 4a-d show other cross-sectional shapes of the outer edge region of a knife 3 or other arrangements of the covers 17, 18:

[0095] At Fig. 4a Both the knife 3 and the covers 17, 18 have the same cross-sectional shape in the outer edge areas as in Fig. 3b, however, the inner cover 17 is arranged differently by being shifted axially into the concave interior 7, i.e., set back from the knife plane 3" towards the outside 3.2 of the knife 3.

[0096] Such an offset also occurs with Fig. 4b is present, however it differs Fig. 4b of Fig. 4a additionally by the fact that the inner cover 17 and the interior 7 in which it is located are designed differently:

[0097] The radial outer edge of the interior 7 is undercut in the axial direction 10, and the radial outer edge of the inner cover 17 dips into this undercut to prevent the ingress of dirt between them.

[0098] Even if there were no undercut, but the radial outer edge of the interior 7 ran parallel to the axial direction 10, and likewise the radial outer edge of the inner cover 7, the risk of contamination between them would already be reduced with a correspondingly small radial distance between them.

[0099] The Fig. Figures 4c and d show a different cross-sectional shape of knife 3 compared to the figures described so far: The contact surface 5, which in this sectional view adjoins the radially inner edge of the ground surface 4, runs parallel to the blade plane 3". Thus, the blade 3 has a uniform thickness 3d2 in this regrinding area 4* defined by the radial extent of the first contact surface 5.

[0100] This ensures that when the knife is resharpened, the effective knife thickness and thus also the radial extent of the grinding surface 4 always remains the same, provided that the radially inner end of the grinding surface 4 is still in the resharpening area 4*, i.e. in the radial area of ​​this connecting surface 5.

[0101] A deflecting shoulder 6" extending obliquely to the knife plane 3" adjoins the radially inner edge of this connection surface 5 on the outer side 3.2 of the knife, so that the thickness of the knife 3 increases radially inwards in the area of ​​the deflecting shoulder 6".

[0102] This deflecting shoulder 6" can be joined to another connection surface 5.1, which in turn lies parallel to the knife plane 3", as shown in Fig. 4c shown.

[0103] At the transition between the deflector shoulder 6" and the connection surface 5.1, a deflector bead 6 can also be formed, which projects axially beyond the further connection surface 5.1 that follows radially behind it, and which naturally also extends the deflector shoulder 6" in the radial direction, as shown in Fig. 4d indicated.

[0104] In this case, the outer cover 18 could extend only as far as the deflecting bead 6, and its deflecting surface 18.2a would, for example, be aligned with the deflecting shoulder 6", possibly offset slightly in a radial direction towards the knife axis 3'.

[0105] The disadvantage of this solution, however, is that, viewed in a radial direction, a large edge area of ​​the outer surface 3.2 of the knife 3 is available for contact with the disc to be cut off, which is precisely what is to be minimized by an outer cover 18.

[0106] Additionally, regardless of the cross-sectional shape of the knife 3 and the outer cover 18, a bead-shaped contact area 19 is formed on the inside 18.1 of the outer cover 18 as a projection in the axial direction towards the knife 3, which rests against the outside 3.2 of the knife 3 and supports the outer cover 18, either radially within the deflecting bead 6, as in Fig. 4d shown, or in the absence of such a repelling - probably the 6 on one of the connecting surfaces 5 or 5.1 as in Fig. 4c shown.

[0107] To prevent the ingress of contaminants between the outer cover 18 and the outer surface 3.2 of the blade 3, the following is shown. Fig. 4c furthermore, that the radially outer edge, in particular with a bead projecting axially over the inner side 18.1, can plunge into an annular groove 21 in the outer side 3.2 of the knife 3.

[0108] Especially if the outer surface 18.2 of the outer cover 18 begins within the depth of the ring groove 21, this further facilitates the sliding of a disc onto this outer surface 18.2.

[0109] The bead or other part of the outer cover that plunges into the annular groove 21 can simultaneously be designed as a contact area 19 and lie against the bottom of the annular groove 21.

[0110] In a resharpening area 4* with constant blade thickness, as is the case in Fig.4c, however, such an annular groove 21 causes the knife to no longer have the same thickness over the entire regrinding area 4*, which is why such an annular groove 21 is preferably not arranged in such a regrinding area 4*, but instead in a radially more inwardly located but also parallel to the knife plane 3" connection surface 5.1 REFERENCE MARK LIST 1 slicing machine 2 cutting units 2a Knife carrier 3 knives 3' Knife axis, rotation axis 3" knife level 3.1 Inside 3.2 Outside 3a Cutting edge 3d2 Thickness Re-grinding area 3D Diameter Knife 4 grinding surface 4* resharpening area 5.1 Connection area 6 Deflector ridge 6" deflector shoulder 7 Interior 7a outer edge 8 Base frame 9 Penetration direction 10 Longitudinal pressing direction, axial direction 11.1, 11.2 Transverse direction 12 square tube 12a Cutting 12' Product Edition 13-blade unit 14 longitudinal press dies 14' Product Push Device 15 Form tube cavity 16 Stop plate 17 Inner cover 17.1 Inside 17.2 Outside 17a outer edge 18 Outer cover 18.1 Inside 18.2 Outside 18a outer edge 18.2a Deflection area 18D Diameter Outer Cover 19 Contact ridge, contact area 20 Immersion area 21 Ring groove α Cutting angle β Deflection angle d Thickness, thickness setting (disc) Product P, material to be cut S disc

Claims

[1] Cutting unit (2) with - a rotating knife (3) that is circular when viewed in the direction of the knife axis (3') and bowl-shaped in cross-section, - whose outer circumferential edge is designed as a circumferential cutting edge (3a) which defines a knife plane (3"), - whose knife axis (3') can be displaced during the cutting process, - wherein the knife axis (3') is mounted in a knife carrier (2a), characterized by , that viewed from the knife axis (3') in the circumferential direction at least in the immersion area (20) - on the concave inner side (3.1) of the bowl-shaped knife (3) an inner, fixed, i.e. not rotating with the knife (3), inner cover (17) is arranged, which at least partially covers the concave interior (7) of the knife (3), and - on the convex outer side (3.2) of the bowl-shaped knife (3) an outer, fixed outer cover (18) is arranged, which does not rotate with the knife (3) and at least partially covers the outer side (3.2) of the knife (3) and whose radial outer edge (18a) is offset radially inwards from the cutting edge (3a). [2] Cutting unit (2) according to claim 1, characterized by , that - the knife axis (3') can be displaced in an oscillating manner during the cutting process, and / or - the inner cover (17) covers the concave interior (7) to at least 90%, preferably at least 95%, and / or - the outer cover (18) covers the outside (3.2) to at least 90%, preferably at least 95%. [3] Cutting unit (2) according to any one of the preceding claims, characterized by , that - the inner cover (17) does not protrude beyond the blade plane (3") in the direction of the blade axis (3'), - is axially recessed, in particular into the concave interior (7), - in particular, it is set back by 0.1 mm to 1.0 mm. [4] Cutting unit (2) according to any one of the preceding claims, characterized by , that - the outer edge (17a) of the inner cover (17) is spaced 2 mm to 6 mm from the outer edge (7a) of the concave interior (7), and / or - the cross-section of the inner cover (17) tapers to a point towards the outer edge (17a) of the inner cover (17), - in particular, into an undercut of the concave interior space (7) that is directed radially outwards in cross-section. [5] Cutting unit (2) according to any one of the preceding claims, characterized by , that - the inner side (18.1) of the outer cover (18) facing the outside (3.2) of the knife (3) runs parallel to the outside (3.2) of the knife (3) and / or - the cross-section of the outer cover (18) tapers to a point towards the outer edge (18a). [6] Cutting unit (2) according to any one of the preceding claims, characterized by , that - the deflecting surface (18.2a) of the outer side (18.2) of the outer cover (18) adjoining the outer edge (18a) runs at a defined deflecting angle (β) to the knife plane (3"), - in particular the deflection angle (β) is greater than the cutting angle (α) at ​​the cutting edge (3a) between the grinding surface (4) and the knife plane (3"), and / or - the cutting angle (α) is between 20° and 25°, and / or - the knife (3) has a thickness of a maximum of 1.5 mm, preferably only a maximum of 1.0 mm, preferably only a maximum of 0.5 mm at the radially inner end of its grinding surface (4). [7] Cutting unit (2) according to any one of the preceding claims, characterized by , that - the outer edge (18a) of the outer cover (18) reaches the inner edge of the polished surface (4) in a radial direction at most, - preferably offset radially inwards relative to the inner edge of the polished surface (4). [8] Cutting unit (2) according to any one of the preceding claims, characterized by , that - the outer cover (18) is adjustable in a radial direction relative to the knife carrier (2a), and / or - the outer cover (18) is immersed in an annular groove (21) provided in the convex outer surface (3.2) of the knife (3). [9] Cutting unit (2) according to any one of the preceding claims, characterized by , that - the outer cover (18) and / or the inner cover (17) has a contact area (19) extending circumferentially around the knife axis (3') for contacting the knife (3). [10] Cutting unit (2) according to any one of the preceding claims, characterized by , that - the knife (3) rotates at a speed of at least 30 rpm, better at a speed of at least 90 rpm, better at a speed of at least 150 rpm, better at a speed of at least 250 rpm when cutting. [11] Cutting unit (2) according to any one of the preceding claims, characterized by , that - the diameter (3D) of the knife (3) is at least 100 mm, preferably at least 400 mm, preferably at least 600 mm, and / or - the weight of the knife (3) is at least 0.1 kg, better at least 0.5 kg, better at least 1.0 kg, better at least 1.5 kg, better at least 1.9 kg. [12] Cutting unit (2) according to any one of the preceding claims 1 to 7 or 9 to 11, characterized by , that - the knife (3) in the regrinding area (4*) that extends radially inwards from the radially inner end of the grinding surface (4) has a constant thickness (3d2), and / or - the concave interior (7) of the knife (3) extends radially outwards to the cutting edge (3a), and / or - the knife carrier (2a) is movably attached relative to the base frame (8) of the cutting unit (2). [13] Slicing machine (1) with - a product edition (12'), and - a cutting unit (2) movable transversely to the feed direction (10) of the product (P) on the product support (12') according to one of the preceding claims, wherein - the direction of entry (9) of the knife axis (3') during cutting runs at an angle of no more than 90°, preferably no more than 70°, preferably no more than 45° to the vertical, and / or - the feed direction (10) of the product (P) during cutting runs at an angle of no more than 90°, preferably no more than 70°, preferably no more than 45° to the horizontal. [14] Slicing machine (1) according to claim 13, characterized by, that the product support (12') comprises a product stop (16), in particular a stop plate (16), against which the product (P) is applied before a disc (S) is cut off. [15] Slicing machine (1) according to claim 14, characterized by , that - the product support (12') comprises a product pusher which presses the product (P) against the product stop (16) when cutting under a preload force of at least 1 N, preferably at least 3 N, wherein in particular - the product pusher device comprises a product pusher (14) movable in the feed direction (10) of the product holder, and / or - the product support (12') is part of a shaped tube (12) that completely encloses the product (P) transversely to the feed direction (10).

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