DE102024105127A1 - Knife shaft and cutting system for chopping food - Google Patents

Abstract

The invention relates to a cutting system for mincing foodstuffs, comprising a knife shaft (110) having a shaft core (111) and at least one knife (112) arranged thereon. The cutting edge (113) formed on the knife lies in a common plane with the rotational axis (A) of the knife shaft (110). This allows for simple manufacture of the knife shaft and good maintainability.

Description

The invention relates to a knife shaft for a cutting system and an associated cutting system, which can be used in particular for chopping food.

From the DE 10 2017 003 406 A1 A cutting system for meat products (meat grinder) is known in which the processed material is transported into a cylindrical drum by a conveyor screw. At the end of the drum, the wall has numerous holes through which minced meat can escape. The meat is cut into small pieces by the holes in the drum and the rotating, sharp-edged screw flights. The problem with this type of cutting system is that the screw flights are complex to manufacture and are subject to significant wear due to their high stress.

Against this background, the object of the present invention was to provide a cutting system which is simpler to manufacture and/or allows easier maintenance.

This object is achieved by a knife shaft according to claim 1 and by cutting systems according to claims 7 and 8. Advantageous embodiments are contained in the subclaims.

• - Einen Wellenkern mit einer Drehachse.
• - Mindestens ein an dem Wellenkern angeordnetes Messer mit einer Schneidkante.

The knife shaft according to the invention is intended for use in a cutting system, whereby the cutting system can be used in particular for chopping food (e.g., meat products). The knife shaft contains the following components:

• - A shaft core with an axis of rotation.
• - At least one knife arranged on the shaft core with a cutting edge.

Furthermore, the knife shaft is characterized in that the said cutting edge lies in a common (imaginary) plane with the axis of rotation and/or runs straight.

The main body of the knife shaft ("shaft core") can, in principle, have any desired shape. Typically, however, it is elongated, with the axis of extension corresponding to the axis of rotation. Furthermore, it is preferably essentially rotationally symmetrical with respect to the axis of rotation. A typical shape of the shaft core is that of a cylinder or truncated cone. The shaft core can, for example, be hollow inside or made of solid material.

The "rotational axis" refers to a predetermined axis on the shaft core, around which it can be mounted for rotation (in an associated cutting system). Therefore, the rotational axis is usually not just an imaginary axis through the shaft core, but also characterized by structural features (e.g., cylindrical sections for mounting in a bearing).

In the following, terms such as “radial”, “tangential” or “axial” are used in relation to the axis of rotation of the shaft core, unless otherwise stated.

Typically, the shaft core lies within a cylindrical volume with a base radius relative to the axis of rotation, and the blade protrudes radially beyond the base radius.

The “cutting edge” is understood here as a (theoretically one-dimensional) line which forms the tip of the knife or at which the cutting processes take place.

Unlike conventional knife shafts, the cutting edge does not run spirally around the rotation axis, but rather is straight and/or in a common plane with the rotation axis. With a straight cutting edge, the cutting edge can be in the same plane as the rotation axis or penetrate this plane at an angle. A cutting edge in the same plane as the rotation axis can be straight or curved.

Only the cutting edge needs to be straight and/or in a common plane with the rotation axis, not necessarily the entire associated blade. For example, the blade could have sections that run spirally with respect to the rotation axis. Typically, however, the blade itself is also straight and/or in a common plane with the rotation axis (or, more precisely, any internal line of the blade that runs parallel to its extension lies in such a plane).

The cutting edge of the blade, which is straight and/or lies in a common plane with the rotational axis, preferably has a certain minimum extension in the axial direction. In particular, the minimum extension should be greater than or equal to the diameter of outlet openings on a drum of the associated cutting system. Preferably, the axial extension of the cutting edge is at least 5%, particularly preferably at least 10% of the total axial length of the shaft core. In absolute terms, the length of the cutting edge is preferably at least 5 mm, particularly preferably at least 20 mm. In addition to the aforementioned cutting edge, which is straight and/or lies in a common plane with the rotation axis, the knife shaft can optionally have additional cutting edges that do not meet this requirement (these can even be located on the same knife and seamlessly connect to the straight cutting edge). For example, the knife could optionally also have cutting edges that run spirally relative to the rotation axis.

Furthermore, the fine structure of the cutting edge can be designed in various ways, in particular smoothly straight, with a serrated edge or the like.

Because the cutting edge of the knife shaft is straight and/or in the same plane as the rotation axis, it can be particularly easily routed. It therefore does not have to have a curved or spiral shape adapted to the drum of the cutting system (as is the case with the DE 10 2017 003 406 A1 This significantly simplifies the manufacturing of the cutting edge. Furthermore, it also facilitates maintenance of the cutting edge, since a straight cutting edge, for example, is easier to resharpen than a curved one.

In principle, the advantages described above are already achieved if only a single cutting edge with the required properties is arranged on the knife shaft. In a preferred embodiment, however, two or more knives are arranged on the shaft core, the cutting edges of which are straight and/or lie in a common plane with the rotation axis. This can be the same plane if the cutting edges are aligned one behind the other in the axial direction (with gaps between them). However, they can also be different planes with respect to the rotation axis (both variants are shown in 7 shown).

In a further development of the above-described embodiment with several knives, the knives are arranged offset on the shaft core in the tangential direction (i.e. in the circumferential direction with respect to the axis of rotation) and/or in the axial direction (with respect to the axis of rotation) (both variants are shown in 7 shown). Optionally, the arrangement is symmetrical with respect to a plane of symmetry containing the axis of rotation and/or symmetrical with respect to a plane of symmetry that is perpendicular to the axis of rotation and/or rotationally symmetrical with respect to the axis of rotation. With such symmetrical arrangements, it can be ensured that loads on the knife shaft occur as evenly as possible and do not lead to one-sided wear. The offset knives are preferably arranged such that their axial extents abut one another or overlap. This ensures that at every point along the axial extent of all knives there is at least one knife that can perform a cutting function (in other words, every hole in a surrounding drum is reached by at least one knife).

The entire blade of the knife shaft and/or at least the cutting edge of the blade is preferably designed to be replaceable. If the cutting edge becomes worn, it can then be quickly and easily replaced with a new one. Such replacement can optionally be carried out without tools or using simple standard tools (screwdriver, wrench, Allen key, or the like). The interchangeability of individual cutting edges or blades enables long, sustainable use of the knife shaft. Furthermore, the knife shaft can also be easily reconfigured in the manufacturing plant or on-site by exchanging blades or cutting edges, for example, to adapt it to the processing of different products and/or use in a different cutting system.

As mentioned, the cutting edge is theoretically a one-dimensional line. It typically lies at the end of a flat or curved cutting surface, which forms a specific angle with the plane containing the cutting edge and the rotation axis. This "cutting edge angle" can optionally be constant along the entire extent of the cutting edge. However, it can also vary position-dependently along the extent of the cutting edge to enable different cutting behavior at different locations. Furthermore, the cutting edge angle can also be adjustable, allowing the user to individually set it as needed (uniformly for the entire cutting edge or position-dependently).

According to a further embodiment, the cutting edge is preferably elastically mounted. This means that the cutting edge can yield to a pressure acting on it (radially and/or from the cutting direction), whereby the restoring forces to the rest position also increase with increasing deflection. Such an effect can be achieved, for example, if the cutting edge is mounted on the blade via a pre-tensioned spring and/or the entire blade is mounted on the shaft core via a spring. With such an elastic mounting, it is then possible to The distance between the cutting edge and the surrounding drum of a cutting system must always be kept to a minimum or within a certain range.

In addition to the knives, the knife shaft can also have at least one additional element, which is also arranged on the shaft core. This could, for example, be a section of a screw thread running spirally around the rotation axis, which ensures the conveyance of the processing material in one transport direction. Since such a screw thread, unlike conventional systems, does not necessarily have to cut the processing material, it is subject to minimal wear and generally does not require extensive maintenance.

• - Eine Trommel mit mindestens einer Auslassöffnung für geschnittenes Verarbeitungsmaterial.
• - Eine in der Trommel um ihre Drehachse drehbar angeordnete Messerwelle gemäß einer der oben beschriebenen Ausführungsformen. Das heißt, dass die Messerwelle mindestens ein an ihrem Wellenkern angeordnetes Messer aufweist mit einer Schneidkante, die gerade ist und/oder in einer gemeinsamen Ebene mit der Drehachse liegt.

The invention further relates to a first cutting system for processing material, in particular for food such as meat products, which contains the following components:

• - A drum with at least one outlet opening for cut processing material.
• - A knife shaft arranged in the drum so as to be rotatable about its axis of rotation, according to one of the embodiments described above. This means that the knife shaft has at least one knife arranged on its shaft core, with a cutting edge that is straight and/or lies in a common plane with the axis of rotation.

The interaction of the perforated drum with the rotating knife shaft ensures that the processing material is pressed under pressure into the outlet openings, where it is cut into small pieces by the cutting edge of the knife shaft. For this purpose, the inner wall of the drum is preferably circular-cylindrical or conical and dimensioned so that the rotating cutting edge of the knife shaft passes as closely as possible to the outlet openings. In particular, the cutting edge and the drum can be dimensioned so that they are in (loose) contact with each other.

Furthermore, the cutting system usually has other common components, for example suitable bearings for the knife shaft relative to the drum, a motor drive for rotating the knife shaft, a conveyor screw for conveying processing material towards the drum, an inlet for processing material, an outlet for residues of the processing material, a closure of this outlet, which is for example sensor-controlled (cf. DE 10 2023 111 458 ) or spring-loaded, and the like. The conveyor screw can, in particular, be designed to be non-rotatable or integral with the knife shaft.

The outlet openings on the drum can be designed in various ways, for example, as cylindrical round holes, slots, elongated holes, or the like. Additionally or alternatively, they can optionally be positioned at an angle other than 90° relative to the inner wall of the drum (see Fig. US 6 622 950 B1 ). In other words, the outlet openings can be angled in the radial, axial, and/or tangential directions. This allows the cutting effect to be influenced as needed in conjunction with the knife shaft.

• - Eine Trommel mit mindestens einer Auslassöffnung für geschnittenes Verarbeitungsmaterial.
• - Eine Förderschnecke mit einem spiralförmigen Schneckengang, welcher in einer ersten Windungsrichtung um die Drehachse der Förderschnecke gewunden ist.
• - Eine in der Trommel um eine Drehachse drehbar angeordnete Messerwelle.

The invention further relates to a second cutting system for processing material, in particular for food such as meat products, which contains the following components:

• - A drum with at least one outlet opening for cut processing material.
• - A screw conveyor with a spiral flight which is wound in a first winding direction around the axis of rotation of the screw conveyor.
• - A knife shaft arranged in the drum so that it can rotate around a rotation axis.

The conveyor screw and the knife shaft are aligned so that their axes of rotation coincide (are identical). Furthermore, the knife shaft has at least one cutting edge that does not run spirally around the knife shaft's axis of rotation in the first winding direction.

In the context of this application, the term "spiral" refers to a curve that winds around an extension axis with a specific direction of rotation (right-handed or left-handed). The distance of the curve from the extension axis can be constant ("helix," "screw") or variable, e.g., decreasing. For further features of the second cutting system, please refer to the above explanations for the first cutting system.

Typically, the screw conveyor and the knife shaft are not only aligned on the same rotation axis, but also positioned close together or adjacent to one another. When the cutting system is in operation, the screw conveyor rotates so that its flight transports the material to be processed toward the drum and thus toward the knife shaft. Within the drum, it is then shredded by the also rotating knife shaft.

Unlike conventional cutting systems with a screw conveyor, the cutting edge (or at least one of them) on the knife shaft does not run spirally in the first winding direction (i.e., the winding direction of the screw conveyor's flight). This provides greater flexibility in the design of this cutting edge and the process behavior of the cutting system.

Specific examples of the cutting edge of the knife shaft include a straight line and a line in a common plane with the knife shaft's rotational axis. These configurations have already been explained above, so reference can be made to the corresponding explanations.

Another concrete example is a spiral-shaped cutting edge, where the spiral's winding direction is opposite to the first winding direction of the screw conveyor's flight. When the screw conveyor and the knife shaft rotate in the same direction around the common axis of rotation during operation, the processing material is forced in different directions by the screw conveyor's flight and the cutting edge of the knife shaft. This can be exploited to specifically influence the pressure conditions within the drum.

The inner wall of the drum in the described cutting systems can, in particular, be circular-cylindrical with a constant diameter along its axial extent, and the cutting edge of the knife shaft can, for example, run parallel to the knife shaft's axis of rotation. In a preferred embodiment, however, the inner wall of the drum and the knife shaft are conical (i.e., in the knife shaft, the movement surface that the cutting edge sweeps over as the knife shaft rotates about the axis of rotation is conical; the cutting edge is then not parallel to the axis of rotation). The two cones of the drum and knife shaft preferably have essentially the same angle, for example, a (relatively small) angle of 1° to 10°.

The conical shape of the drum and knife shaft described above can be used, in particular, to adjust the distance between the cutting edge and the inner wall of the drum as needed. For this purpose, the cutting system is preferably designed so that the axial position of the knife shaft relative to the drum is adjustable or changeable. During assembly of the cutting system and/or during maintenance work and/or automatically during operation, the aforementioned distance can then be easily (readjusted).

• 1 eine perspektivische Außenansicht einer ersten Ausführungsform eines Schneidsystems mit drei sich über die gesamte axiale Länge der Messerwelle erstreckenden Messern und Schneidkanten;
• 2 eine Ansicht wie 1 aus einer näher an der Drehachse gelegenen Perspektive;
• 3 eine separate Ansicht der Messerwelle des Schneidsystems von 1;
• 4 eine Prinzipskizze mit verschiedenen Lagen der Schneidkante;
• 5 einen Schnitt entlang der Drehachse eines Schneidsystems gemäß einer zweiten Ausführungsform, bei welchem sich die Messer bzw. Schneidkanten nur über ungefähr die halbe axiale Länge der Messerwelle erstrecken;
• 6 eine perspektivische Ansicht des Schneidsystems von 5;
• 7 eine separate Ansicht der Messerwelle gemäß einer dritten Ausführungsform mit einzelnen Messerblöcken.

The invention is explained in more detail below with the aid of exemplary embodiments and the accompanying figures. Herein:

• 1 a perspective external view of a first embodiment of a cutting system with three knives and cutting edges extending over the entire axial length of the knife shaft;
• 2 a view like 1 from a perspective closer to the axis of rotation;
• 3 a separate view of the knife shaft of the cutting system of 1 ;
• 4 a schematic diagram with different positions of the cutting edge;
• 5 a section along the rotational axis of a cutting system according to a second embodiment, in which the knives or cutting edges extend only over approximately half the axial length of the knife shaft;
• 6 a perspective view of the cutting system of 5 ;
• 7 a separate view of the knife shaft according to a third embodiment with individual knife blocks.

First, a first embodiment of a cutting system 100 is described with reference to 1 to 3 This and the other cutting systems described are typically part of a larger food processing device, such as those used in WO 2022/258171 A1 (which is fully incorporated into the present application).

• - einer perforierten Trommel 101 mit einem kreiszylindrischen Innenraum und
• - einer Messerwelle 110, welche drehbar im Innenraum der Trommel 101 angeordnet werden kann.

The cutting system 100 essentially consists of two components, namely

• - a perforated drum 101 with a circular cylindrical interior and
• - a knife shaft 110, which can be rotatably arranged in the interior of the drum 101.

The knife shaft 110, which is mounted in the interior of the drum 101 so as to be rotatable about a rotation axis A, is in 3 shown separately. It comprises a tubular (hollow) shaft core 111, which can essentially be described geometrically as a circular cylinder. Alternatively, the shaft core could also be (slightly) conical and/or made of solid material.

On the outer surface of the shaft core 111, three knives 112 are arranged circumferentially and evenly distributed at an angular distance of 120°, which extend straight and parallel to the axis of rotation A. The knives 112 each have a cutting edge 113 on one side or on both sides with respect to the circumferential direction (pointing in the direction of the subsequent rotation). The cutting edges 113 also run straight and parallel to the axis of rotation A. This means that for each cutting edge 113 there is a plane which contains both the axis of rotation A and the cutting edge 113. Unlike in known meat grinders, the knives are therefore not curved and spiral around the axis of rotation, which considerably simplifies their manufacture and maintenance.

The cutting edge 113 of a knife 112 is typically located at the end of a cutting surface, which forms a specific angle with the plane that jointly contains the rotational axis A and the cutting edge 113. This "cutting edge angle" can be constant, position-dependent, and/or adjustable along the extent of the cutting edge. It is preferably between approximately 0° and approximately 50°, particularly preferably between approximately 20° and approximately 40°.

The described knife shaft 110 is as shown in the 1 and 2 shown in use, arranged inside the drum 101 so that the cutting edges 113 of the three knives 112 move closely along the inner wall of the drum. In the illustrated embodiment, the drum 101 consists of a first section 102, which is perforated in a sieve-like manner by a plurality of radially extending circular holes. The holes can optionally also have cross-sections other than circular and/or vary in diameter along their radial extent, for example, from 3 mm to 5 mm. Axially adjacent to this is a second section 103, which has a single, elongated opening running in the axial direction.

During operation of the device, the knife shaft 110 is mounted for rotation about the rotation axis A in a manner not shown in detail and is rotated relative to the drum 101 by a motor. Processing material (e.g., meat products) transported under pressure into the interior of the drum 101 is then pressed into the openings in the wall of the drum 101. When a cutting edge 113 then passes the respective opening due to the rotation of the knife shaft 110, it cuts off the processing material located in the opening, allowing it to exit in shredded form.

• - Die Schneidkante SK1 liegt komplett in derselben Ebene E wie die Drehachse A und verläuft gerade. Sie kann (wie dargestellt) parallel zur Drehachse A verlaufen oder schräg hierzu.
• - Die Schneidkante SK2 liegt ebenfalls komplett in derselben Ebene E wie Drehachse A, verläuft jedoch gekrümmt.
• - Die Schneidkante SK3 verläuft gerade und liegt nicht in einer gemeinsamen Ebene E mit der Drehachse A, sondern durchstößt eine solche Ebene unter einem Winkel ungleich 0°.
• - Die Schneidkante SK4 verläuft spiralförmig mit einer Windungsrichtung (Gängigkeit), die entgegen der Windungsrichtung einer vorgelagerten Förderschnecke (nicht dargestellt) ist. Da die Schneidkante SK4 rechtsgängig dargestellt ist, wäre die Förderschnecke also linksgängig.

In 4 Some possible positions and paths of the cutting edges of a knife shaft according to the present application are schematically sketched. The dashed line AA represents the rotational axis A of the knife shaft, and the plane E represents one of the (infinitely many) planes containing the rotational axis. The following cutting edge paths are shown:

• - The cutting edge SK1 lies entirely in the same plane E as the rotation axis A and runs straight. It can run parallel to the rotation axis A (as shown) or at an angle to it.
• - The cutting edge SK2 also lies completely in the same plane E as the rotation axis A, but is curved.
• - The cutting edge SK3 is straight and does not lie in a common plane E with the rotation axis A, but penetrates such a plane at an angle not equal to 0°.
• - The SK4 cutting edge runs spirally with a winding direction (threading) that is opposite to the winding direction of an upstream screw conveyor (not shown). Since the SK4 cutting edge is shown as right-handed, the screw conveyor would therefore be left-handed.

In the 5 and 6 A modified cutting system 200 is shown. Identical or similar components as in the first embodiment bear reference numerals increased by 100 and will not be described in detail again below.

Similar to the first-described cutting system, the cutting system 200 also includes a drum 201 in which a hollow knife shaft 210 is rotatably mounted. The three knives 212 of the knife shaft 210 each have a cutting edge 213, which lies in a common plane with the rotational axis A. 5 the drawing plane for one of the knives 212 is just such a plane which contains the cutting edge 213 of the knife and the rotation axis A.

Unlike the first embodiment, the three knives 212 on the knife shaft 210 extend only over approximately half the axial length of the shaft core 211 and are located only in the downstream (perforated) area of the drum 201 in the conveying direction.

As can be seen from the section along the rotation axis A in 5 As can be seen, the knife shaft 210 is arranged in a rotationally fixed manner on the cylindrical end section 222 of a rotatable conveyor screw 220. The conveyor screw 220 has, in its section located outside the drum 201, spirally rotating screw flights 221. With the help of these screw flights 221, processing material can be conveyed in a known manner from an inlet (not shown). provided) are transported through a pressure chamber (not shown) toward the drum 201 and pressed into the drum. The cutting process then takes place in the drum 201, whereby further axial conveyance of the processing material is not absolutely necessary, since the conveyor screw 220 constantly ensures the necessary pressure build-up.

At its downstream axial end, the cylindrical section 222 of the conveyor screw 220 has an internal thread 223. Optionally, further components can be connected to this, such as a pin that extends the conveyor screw 220 in the conveying direction (see WO 2022/258171 A1 ).

In 7 Another embodiment of a knife shaft 310 is shown as a representative of many possible variations.

The knife shaft 310 is again designed as a hollow body with a tubular shaft core 311. This time, however, the outer surface of the shaft core 311 is not provided with axially elongated knives, but rather with individual knob-like blocks of knives 312 limited in their axial length, each with cutting edges 313 provided thereon. In the illustrated embodiment, two knives 312 are arranged one behind the other in the axial direction, and three such groups of two knives each are evenly distributed around the circumference at an angular spacing of 120°. In total, this results in six individual knife blocks 312 on the knife shaft 310.

The axial extents of the knife blocks 312 are coordinated such that (at least) two knife blocks always overlap in terms of their axial extent. Thus, when the knife shaft 310 is inserted into one of the drums 101 or 201 described above, there is at least one knife 312 at each hole in the drum wall, which passes by as the knife shaft 310 rotates.

The described designs of knife shafts or cutting systems have the advantage that the cutting edges of the knife shafts are straight. They are therefore considerably easier to manufacture and maintain.

• - Schneidsystem mit perforierter Trommel (Löcher, Schlitze, Langlöcher, etc.) worin eine Messerwelle rotiert.
• - Die Messerkante (Schneidkante) verläuft parallel zur Drehachse.
• - In der Trommel können sich ein oder mehrere Segmente befinden.
• - Die Schneidkante kann einen oder mehrere Schneidwinkel haben.
• - In der Trommel können die Öffnungen schräg angestellt sein.
• - Die Schneidkante kann in Förderrichtung unterbrochen sein
• - Das Messer kann fest oder auswechselbar sein.
• - Die Schneidkante kann fest oder auswechselbar sein.
• - Die Trommel und die Schneide können konisch verlaufen, so dass man durch Verschieben den Schneidspalt einstellen kann.
• - Die Schneidkante kann federvorgespannt sein, so dass sie sich automatisch am optimalen Schneidspalt einstellt.
• - Die Messerwelle kann sowohl aus Vollmaterial als auch hohl ausgestaltet sein.
• - Die Schneidkante kann glatt oder unterbrochen sein (z.B. Wellenschliff).

Important or advantageous optional features of the embodiments are:

• - Cutting system with perforated drum (holes, slots, elongated holes, etc.) in which a knife shaft rotates.
• - The knife edge (cutting edge) runs parallel to the axis of rotation.
• - There can be one or more segments in the drum.
• - The cutting edge can have one or more cutting angles.
• - The openings in the drum may be angled.
• - The cutting edge may be interrupted in the conveying direction
• - The blade can be fixed or replaceable.
• - The cutting edge can be fixed or replaceable.
• - The drum and the cutting edge can be tapered so that the cutting gap can be adjusted by moving them.
• - The cutting edge can be spring-loaded so that it automatically adjusts to the optimal cutting gap.
• - The knife shaft can be made of solid material or hollow.
• - The cutting edge can be smooth or interrupted (e.g. serrated).

QUOTES CONTAINED IN THE DESCRIPTION

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

Cited patent literature

• DE 10 2017 003 406 A1 [0002, 0016]
• DE 10 2023 111 458 [0025]
• US 6 622 950 B1 [0026]
• WO 2022/258171 A1 [0037, 0049]

Claims (10)

Knife shaft (110, 210, 310) for a cutting system (100, 200), in particular for comminuting foodstuffs, comprising: - a shaft core (111, 211, 311) with a rotation axis (A); - at least one knife (112, 212, 312) arranged on the shaft core (111, 211, 311) with a cutting edge (113, 213, 313, SK1, SK2, SK3), characterized in that the cutting edge (113, 213, 313, SK1, SK2, SK3) lies in a common plane with the rotation axis (A) and/or runs straight. Knife shaft (110, 210, 310) after Claim 1 , characterized in that two or more knives (112, 212, 312) are arranged on the shaft core (111, 211, 311), the cutting edges (113, 213, 313, SK1, SK2, SK3) of which lie in a common plane with the axis of rotation (A). Knife shaft (110, 210, 310) after Claim 2 , characterized in that the knives (112, 212, 312) are arranged offset in the tangential and/or axial direction on the shaft core (111, 211, 311). Knife shaft (110, 210, 310) according to at least one of the preceding claims, characterized in that the knife (112, 212, 312) and/or the cutting edge (113, 213, 313) of the knife is replaceable. Knife shaft (110, 210, 310) according to at least one of the preceding claims, characterized in that the angle of the cutting edge (113, 213, 313) along the extension of the cutting edge is constant, position-dependent and/or adjustable. Knife shaft (110, 210, 310) according to at least one of the preceding claims, characterized in that the cutting edge (113, 213, 313) is elastically mounted. Cutting system (100, 200) for processing material such as foodstuffs, comprising - a drum (101, 201) with at least one outlet opening for cut processing material; - a knife shaft (110, 210, 310) arranged in the drum (101, 201) so as to be rotatable about its rotational axis (A) according to at least one of the Claims 1 until 6 . Cutting system (100, 200) for processing material such as food, in particular after Claim 7 , comprising - a drum (101, 201) with at least one outlet opening for cut processing material; - a conveyor screw (220) with a spiral screw flight (221) which is wound in a first winding direction around the axis of rotation (A) of the conveyor screw (220); - a knife shaft (110, 210, 310 arranged in the drum (101, 201) so as to be rotatable about its axis of rotation (A); wherein the axes of rotation (A) of the conveyor screw (220) and the knife shaft (110, 210, 310) coincide and the knife shaft (110, 210, 310) has a cutting edge (113, 213, 313, SK1, SK2, SK3, SK4) which does not run spirally in the first winding direction around the axis of rotation (A) of the knife shaft (110, 210, 310). Cutting system (100, 200) according to Claim 8 , characterized in that - the cutting edge (113, 213, 313, SK1, SK3) runs straight; - the cutting edge (113, 213, 313, SK1, SK2) runs in a common plane with the axis of rotation (A) of the knife shaft (110, 210, 310); and/or - the cutting edge (SK4) runs spirally around the axis of rotation (A) of the knife shaft, counter to the first winding direction. Cutting system (100, 200) according to at least one of the Claims 7 until 9 , characterized in that the inner wall of the drum (101, 201) and the movement surface of the cutting edge (113, 213, 313) of the knife shaft (110, 210, 310) are conical, wherein preferably the axial position of the knife shaft relative to the drum is adjustable.