EP2384817B1 - Ring knife for cutting sets of grinding machines - Google Patents

Description

The invention relates to a ring knife for multi-part, consisting of stationary perforated discs and at least one rotary knife cutting sets of crushing machines, especially for meat grinders and the like, comprising an inlet side and an outflow side having knife body with a hub and an outer ring and a plurality extending between the hub and outer ring Knife blades carrying knife blades which, together with the outer ring and the knife hub, limit knife spaces, as well as cutter blades carrying knife blades which extend from the outer ring into the knife spaces. Furthermore, the invention is directed to crushers with such ring knives.

From the DE 43 01 787 Ring knives for crushing machines, especially meat mincers, known with simple or multi-part cutting sets, the cutter bar provided with knife blades and fixed to an outer ring and the hub of the knife, forming spaces in the form of knife chambers, are connected. The peculiarity of this knife, which is also referred to as a ring knife, is that knife blades hanging in the intermediate space and directed towards the area of the knife means are fixedly arranged on the outer ring. Such ring knives work together in sets of fixed perforated discs, it being advantageous that, in particular when mincing meat, up to 80% of the processed material conveyed by the working screw of a meat grinder is pressed onto the outer region of the perforated disc and fastened by the outer ring and only in the outer ring Effective area of the perforated disc Hanging knife blades a higher throughput is achieved, ie a homogenization of the throughput is achieved by the perforated disc.

From the DE 32 15 950 A1 is a cutting set for meat grinders with a ring knife known in which only continuous, ie provided from the hub area to the outer ring knife blades are provided. The cutter bar, which carry the cutting blades are provided lying in the direction of rotation in front of the respective cutting blade with oblique thrust surfaces for the material to be cut, these thrust surfaces serve to fully capture the supplied cutting material and reliably push through the subsequent perforated disc. It should be ensured that even soft and / or fatty meats are heated as low as possible in order to increase the throughput of the meat grinder.

In the case of comminution devices with cutting sets of knives and perforated disks, the comminution process takes place at least in two phases.

In a coarse comminution phase takes the first perforated disc ("entrance hole disc" or "rough perforated disc") with comparatively large openings the respective raw material in a large, mechanically compact form and it is at the exit or downstream side of the perforated disc with the side facing knife blades means Shear action made a coarse crushing of the raw material. The shearing action is caused by the interaction of the knife blades with the edges of the perforated disc bores. In this process occur due to the material compactness of the raw material on large forces, so that the knives or knife carrier in this area must be very strongly dimensioned.

The mentioned comminution phase has the consequence that the material, mechanical strength is considerably reduced by smaller pieces and the raw material part size can penetrate better into subsequent smaller perforated disc bores. These smaller holes are formed in the next perforated disc following in the flow direction on the blade. Accordingly, the knife is located between a rough perforated disc and a fine perforated disc, wherein the knife is preferably designed as a ring knife and present between the substantially radially extending cutter bar of the ring diameter on both sides limited by the perforated disc cutter chambers.

It is essential for the function that raw material penetrating into the holes of the fine perforated disk can only leave the fine perforated disk again if it is severed directly after penetration into the corresponding bore by the shearing action of the knife blades on the knife-side bore edge. If there is no blade available for this required separation process immediately after penetration of the raw material into the corresponding bore of the fine perforated disc, the raw material penetrating into the perforated disc bore is again pushed out of the bore, ie it can not be cut uniformly over the entire perforated disc surface, since the distance between the Successively effective knife blades for the hole assembly is given at a given rotational movement of the knife is too large. With standard knives, the cutting performance can easily be reduced by up to 60%.

Furthermore, for all perforated disks, each hole opening represents a single cutting tool and these individual cutting tools can only work if the openings or holes in the perforated disks are unobstructed by the cutter blades carrying the knife blades available. Thus, if portions of the perforated disc are covered by the cutter bar, the material to be processed can not simultaneously penetrate into all holes due to the applied thrust pressure, as a result of which the perforated disc power decreases. Conventionally designed knife bodies often obscure 30% to 40% of the perforated disc openings and thus reduce the number of effective cutting tools of the perforated disc. These adverse effects are particularly evident in fine perforated discs, since here the number of holes is particularly large.

Since very high forces occur in the coarse comminution phase in the already mentioned manner, the known standard knives are designed for maximum mechanical load and accordingly the knife blades carrying the cutter bar correspondingly large, which has the consequence that in the conveying direction of the raw material undesirably large flow resistance arise and this spatially large cutter bar cover by their surface a large part of the perforated disc surface or the individual cutting tools forming holes of the perforated disc. This has the consequence that the performance of such cutting sets is not satisfactory, because the crushed raw material in the holes of the second perforated disc or fine perforated disc can not be cut fast enough with the time-required separating cut, since the path of movement from the knife to the respective hole is too large ,

The object of the invention is therefore in particular, a ring cutter of the type described in such a way that the different mechanical stresses of the successive cutting sequences can be taken into account when the mechanical state of the raw material has changed, and the efficiency of the cutting sets is substantially increased.

This object is achieved with a ring knife with the features of claim 1 and a device for mincing food with the features of claim 8.

This object is achieved according to the invention, therefore, essentially by the fact that the number of effector blades located downstream is greater than the number of effective knife blades located on the inflow side, and that the blade chambers expand in the direction of the flow through the blade body.

The term "inflow side" is used for the knife side, which is arranged upstream in the flow direction of the material to be crushed. The "outflow side" corresponds to the side of the knife body, which is arranged downstream in the direction of the flow. The "direction of the flow" is defined by the direction in which moves the material to be crushed in the crushing process through the knife chambers of the knife body. The term "blade" is used herein to refer to those elements of the blade having cutting edges.

The design of the knife chambers according to the invention achieves, inter alia, that the forces acting on the ring knife are taken into account practically separately according to the rough section, ie, a large load, and a fine cut, ie, a lower load. Due to the increased number of downstream knife blades in comparison to the inflow side it is achieved that the advantageously high cutting sequences are achieved, so that an optimum penetration rate of the raw material into the holes ensures and the material can be removed again from the holes.

Furthermore, it is important that can be worked by the extension made in the flow direction of the knife chambers with a very low degree of concealment of perforated disc bores, i. it is the largest possible number of individual tools of the perforated disc, i. Bore edges effective. This increased perforated disc working surface on the downstream of the ring diameter in the flow direction subsequent fine perforated disc requires more cuts in a shorter time, and this is ensured by the larger selected number of downstream effective knife blades. It is thus achieved a particularly high crushing performance by effective separation work of raw material, hole edges and knife blades time related.

Starting from an inflow-side maximum dimension of their cross-section, the solid-diameter bars preferably have a cross-section which reduces toward the outflow side. In this way, account can be taken of the fact that for the rough cut about 75% of the engine power and for the fine cut only about 25% of the engine power of the ring knife driving motor is needed. The Vollmesserbalken can accordingly have on the higher loaded side about three times the material cross section compared to the material cross section on the fine cut side. Since the Vollmesserbalken to the fine perforated disc directed towards accordingly have a decreasing cross-section, ie can be wedge-shaped, corresponding Lochscheibewirkfläche is free on the Feinlochscheibenseite.

While for the coarse cut side, due to the slower penetration of the coarse pieces of raw material into the holes of the orifice plate, a relatively large gap must be kept between consecutive knife blades, additional knife blades are required on the fine orifice plate side to ensure that with the higher number of holes in the fine perforated disc and in view of the faster flowing raw material the timely separating cuts can be performed on the perforated disc surface. These timely separating cuts can be achieved by the downstream larger number of effective knife blades, which are provided on the Teilmesserbalken. Only by this higher number of knife blades on the outer ring extending inwardly Teilmesserbalken that work together with the fine perforated disc, the physical processes of raw material processing, consisting of the penetration and Abschneidezyklus, optimally met.

It is particularly advantageous if the Teilmesserbalken at least partially starting from the outer ring over its length have a decreasing cross-section, wherein the inflow-side boundary surfaces of these Teilmesserbalken spaced with respect to the formed by the cutting edges of the knife blades on the inflow side inflecting knife plane and in particular increasingly from the outer ring to the inside are spaced.

This also contributes significantly to the enlargement of the knife chambers of the knife body as well as to the fact that practically no obstruction exists in the flow.

The essential for the invention extension of the knife chambers in the flow direction of the knife body is preferably by appropriate Wandungsschrägen of solid blade and / or knife blade and / or outer ring and / or hub reached. Preferably, all these measures are used simultaneously.

Between two juxtaposed solid knife bars with associated knife blades more than one Teilmesserbalken with associated knife blade can be provided, as in the outer area of the perforated disc in which the knife blades of the cutter bars are effective, about 80% of all holes are located. It is always desirable that each of the same number of knife blades per hole on the spatial surface for cutting execution can be provided. The number of cutting edges of the cutter bars and the cutting edges of the cutter bars is matched with the bore sizes, the material state shapes and the time pressure-related penetration behavior of the raw material into the holes with the machine parameters. This is advantageous because the entire process takes place at knife speeds of 200 to 400 revolutions per minute. Since the raw material is under shear pressure in a knife chamber and always penetrates completely into all holes of the perforated disc at the same time, the simultaneous shearing or separating cut must be at least substantially secured with all knife blades on the perforated disc. In this way, the knife and orifice plate performance compared to the known arrangement can be easily increased by 80% and even up to 100%.

These advantageous effects and results are achieved on the so-called coarse side - ie the upstream side of the blade - especially by a good raw material intake due to large distances between the force-transferring Vollmesserbalken and by the back in the flow direction Teilmesserbalken for the purpose of eliminating disturbances in the penetration of the raw material in the respective knife room.

On the so-called fine side - ie the outflow side of the knife - the increase in the number of knife blades to produce shorter cutting cycles and the reduction of the cross section of the cutter bar in the direction of flow to increase the working surface on the fine perforated disc advantageous.

In addition to the ring knife described above, the invention also includes a device for mincing food, in particular for mincing meat and the like, with at least one perforated disc ring cutter set, in which the inflow side of at least one perforated disc is assigned a ring knife of the type described with its downstream side ,

Further advantageous embodiments and features of the invention are specified in the subclaims and are also explained in the following description of exemplary embodiments.

Fig. 1

eine Draufsicht auf die Abströmseite einer Ausführungsform eines erfindungsgemäßen Ringmessers,

Fig. 2

eine Draufsicht auf die Zuströmseite dieses Messers,

Fig. 3

eine Schnittzeichnung des Messers, wobei die Schnittebene in Fig. 1 und in Fig. 2 mit III-III angegeben ist,

Fig. 4

eine Schnittzeichnung durch einen Teil des Messers, wobei die Schnittebene in Fig. 1 und in Fig. 2 mit IV-IV angegeben ist,

Fig. 5

einen alternativen Querschnitt eines Vollmesserbalkens, und

Fig. 6

eine schematische Seitenansicht eines beispielhaften Schneidsatzes eines Fleischwolfes.

The invention will be explained in detail with reference to the accompanying figures, which illustrate an embodiment of a ring knife according to the invention. Show

Fig. 1

a plan view of the downstream side of an embodiment of a ring knife according to the invention,

Fig. 2

a plan view of the upstream side of this knife,

Fig. 3

a sectional drawing of the knife, wherein the cutting plane in Fig. 1 and in Fig. 2 indicated with III-III,

Fig. 4

a sectional view through a part of the knife, wherein the cutting plane in Fig. 1 and in Fig. 2 with IV-IV,

Fig. 5

an alternative cross section of a Vollmesserbalkens, and

Fig. 6

a schematic side view of an exemplary cutting set of a meat grinder.

The FIGS. 1 to 4 show a ring knife 10 of a cutting set of a food crusher, for example a meat grinder, which rotates about an axis 12. The knife is driven by a shaft, not shown, which cooperates positively with the central two-edged opening 14. The knife rotates in operation in the direction of arrow 16. Fig. 1 shows the plan view of the downstream side of the knife, while Fig. 2 a plan view of the inflow side shows. The flow direction of the material to be shredded is accordingly indicated by the symbols 18. In a meat grinder, meat is the material to be shredded. In the following, for the sake of simplicity, meat is always referred to as material to be comminuted, without this being to be understood as limiting.

From the hub 20, full blade bars 22 extend outwardly. In the embodiment shown, six such Vollmesserbalken 22 are provided, of which for clarity, only a part is provided with reference numeral. The embodiment shows six equally spaced solid knife bars 22. Other numbers are also possible, for example three, four or more.

The full blade bars 22 terminate at an outer ring 24, which may for example have an outer diameter of 15 to 20 cm. The thickness of the knife body in the direction of flow is, for example, one to a few centimeters.

The full blade bars 22 comprise on the downstream side of the blade 10, which in Fig. 1 visible, knife blades 26, of which in turn only a few are provided with reference numerals. They serve to separate the meat which has passed through the openings 34 of the knife 10. On the upstream side of the knife 10, the in Fig. 2 is shown, the Vollmesserbalken 22 knife blades 28, of which also only a few are provided with reference numerals.

Both the knife blades 26 on the downstream side of the blade 10, and the knife blades 28 on the upstream side of the blade 10 are not exactly aligned radially. Instead, the inner end of the knife blades 26, 28 (and thus also the knife edges) precede the outer end, which is farther from the hub 20, in the direction of rotation 16 of the rotating knife 10, thereby achieving good shearing of the meat. In some raw materials, however, it may also be useful if the orientation of the cutting is chosen the other way around, so in particular the ends of the knife blades close to the hub run after the ends remote from the hub in the direction of movement of the rotating blade. Such an embodiment ensures that the meat moves in the openings towards the center.

The cross section of a metering bar 22 is in Fig. 4 shown. In the Fig. 1 and 2 is the line of sight of Fig. 4 shown on this cross section with IV-IV. In Fig. 4 the flow direction of the meat is again denoted by 18. The line of sight in Fig. 1 is visible in is Fig. 4 denoted by I. The line of sight in Fig. 2 is visible in is Fig. 4 denoted by II. Arrow 16 again indicates the direction of movement of the cutter bar 22 when the knife 10 is rotating.

In particular, in Fig. 4 recognizable that on the trailing in the direction of rotation 16 of the knife side of the Vollmesserbens 22 bevel 30 is provided, which causes the Vollmesserbalken 22 on the upstream side of the blade 10 is wider than on the downstream side. The support cross-sectional width 46 of a full-diameter bar 22 is thus greater on the inflow side than the support cross-sectional width 48 on the outflow side.

The chamfers 30 are also in Fig. 1 visible, and here they are provided for clarity only in some of the Vollmesserbalken 22 with reference numerals. The chamfers 30 extend in this embodiment along the entire length of the respective Vollmesserbalkens 22 and along the outer ring 24th

Alternative embodiments provide that no chamfer 30 is provided, but, for example, a concave shape, which is designed such that the Vollmesserbalken are wider on the upstream side than on the downstream side. Such a possible cross-sectional shape is in Fig. 5 wherein reference numeral 32 denotes the concave, in the direction of rotation 16 of the rotating blade 10 trailing surface of the Vollmesserbalkens 22.

Two adjacent solid blade bars 22 and outer ring 24 each form openings 34 in the blade which act as individual pressure chambers. The bevels 30 and the concave surfaces 32 ensure that the openings 34 expand in the direction of flow 18. The achievable by reducing the width of the Vollmesserbalken 22 Extension of the openings 34 in the direction of flow 18 of the meat can be, for example, 30% of the opening size of the openings 34.

Between two adjacent solid blade bars 22 extending from the outer ring 24 splitter blade 36 in the direction of the hub 20 inwardly, of which in the Fig. 1 and 2 again not all are marked with reference numerals. The metering blades 36 are supported only on the outer ring 24 and end in the embodiment shown about half the distance between the outer ring 24 and the hub 20th

On the downstream side of the knife 10, the in Fig. 1 is shown, these cutter blades 36 carry knife blades 38, which point in the direction of the hub 20. In the embodiment shown, these knife edges are not exactly aligned radially. Instead, they are arranged obliquely so that the ends of the knife blades close to the ends run ahead of the ends in the direction of movement 16 of the rotating blade 10, whereby a good shearing off of the meat is achieved. In some raw materials, however, it may also be useful if the orientation of the cutting is chosen the other way around, so in particular the ends of the knife blades close to the hub run after the ends remote from the hub in the direction of movement of the rotating blade.

In the embodiment shown, exactly one partial knife bar 36 is arranged between each two solid cutter bars 22. In other embodiments, not shown, two or more metering blades 36 are provided with corresponding cutter blades 38 between two Vollmesserbalken 22. Still other embodiments provide that not in all openings 34 between two Vollmesserbalken 22 one or more Teilmesserbalken 36 are provided.

Fig. 3 shows a section through the knife 10, the direction of view of this section in the Fig. 1 and 2 marked with III-III. In the sectional view of Fig. 3 the flow direction of the meat is again indicated by the arrow 18.

The view towards the downstream side, the in Fig. 1 is recognizable, is in Fig. 3 indicated with I. The viewing direction on the upstream side of the knife 10, the in Fig. 2 is shown in is Fig. 3 indicated with II. In the direction II, one looks at the blade surface 40 of the upstream side of the blade 10. The blade surface 40 corresponds to the blade plane which is formed by the cutting edges of the blade blades 28 of the full blade 22 on the inflow side.

In the sectional view of Fig. 3 It can be seen that the meter blades 36 on the upstream side, the in Fig. 2 is shown jumping back at the end close to the hub, so that between the blade surface 40 and the blade bar 36 an increasing distance towards the center 42 is realized. This is achieved by a correspondingly configured oblique or concave surface 44 of the cutter bar 36.

On the meter blade 36 are only on the downstream side of the blade 10, the in Fig. 1 shown knife blades 38 is provided.

The described embodiment of the knife 10 according to the invention acts as follows.

An exemplary cutting set 54 with a knife 10 is shown in FIG Fig. 6 shown. The knife 10 rotates in this embodiment about the axis 12 between two fixed perforated discs 50 and 52nd

The first perforated disc 50, which at the in Fig. 2 visible upstream side of the blade 10 has, in comparison to the second perforated disc 52, which at the in Fig. 1 visible downstream side of the blade 10 is arranged, larger holes 56 in a correspondingly smaller number per area. The second perforated disk 52 is therefore also referred to as a fine perforated disk and the first perforated disk 50 as a rough perforated disk. For example, the pinhole disk 52 has twenty-two to fifty holes 58, and the rough hole disk 50 has three to seven holes 56. The holes 56 in the rough hole disk 50 and the holes 58 in the pinhole disk 52 are shown in FIG Fig. 6 only partially provided with reference numbers.

The meat enters the openings 34 of the rotating blade 10 through the holes 56 of the roughing hole 50 located on the upstream side of the blade 10. The knife blades 28 on the upstream side of the blade 10 separate the meat that collects in the openings 34. The entry of the meat into the openings 34 is not substantially hindered by the metering blades 36, since these are at least partially set back on the upstream side of the blade 10, as shown in FIG Fig. 3 is visible.

The meat entered into the openings 34 is pressed onto the fine perforated disk 52, which adjoins the rotating blade 10 in the cutting set in the direction of flow 18 and is likewise generally stationary. This fine perforated disc 52 has more and smaller holes 58 than the rough perforated disc 50. Because the solid carbide blades 22 on the downstream side of the blade 10 have a smaller span width as on the upstream side, it is ensured that the meat located in an opening 34 can hit a larger number of holes 58 in the fine perforated disk 52 than if the solid blade bars 22 had a constant width in the throughflow direction 18.

The meat which enters through the openings 34 in the holes 58 of the subsequent fine perforated disc 52 is separated in particular by the knife blades 26 on the full blade bar 22. In addition, a separation is effected in particular in the radially outer region of the blade 10 by the blades 38 on the metering blade 36. In this way, the increased discharge performance is taken into account by the increasing cross sections of the openings 34.

The described embodiment of the knife of a cutting set of a food shredder combines several advantages. By reducing the width of the Vollmesserbalken 22 in the direction of flow 18 of the meat through the chamfers 30 ensures that on the downstream side of the knife 10 a larger area and thus a larger number of holes 58 of the subsequent fine perforated disc 52 is acted upon by the meat than in a conventional Knife. The reduction in the width of the solid blade bars 22 is not detrimental to the stability of the blade as there are only about 25% of the rotational forces on the downstream side as compared to about 75% of the rotational forces occurring on the upstream side. On the thus far more loaded upstream side of the Vollmesserbalken 22 are wider.

By the Teilmesserbalken 36, which are increasingly spaced from the outer ring 24 in an increasing manner to the surface 40 of the blade 10 of the upstream side, the entry of the meat into the openings 34 is not or not substantially hindered. Nevertheless, it will open the outflow side of the blade 10 by the Teilmesserbalken 36 with the blades 38 reaches a high cutting performance, so that the guaranteed by the enlargement of the openings 34 performance increase can be processed and cut well especially on the downstream side. <B><u> REFERENCE LIST </ u></b> 10 knife 12 axis 14 Two polygonal opening 16 Direction of rotation of the knife 18 flow direction 20 hub 22 Full cutter bar 24 outer ring 26 Knife blade on the downstream side of a full-grain bar 28 Knife blade on the inflow side of a solid knife bar 30 bevel 32 concave surface 34 opening 36 Part cutter bar 38 Knife blade of a cutter bar 40 Knife surface on the inflow side 42 distance 44 area 46 Support cross-section width of a full-diameter bar on the inflow side 48 Support cross-section width of a full-diameter bar on the downstream side 50 Coarse perforated disc 52 Finely perforated disc 54 cutting set 56 Hole in the perforated plate 58 Hole in the fine perforated disc I Looking towards the downstream side of the knife II Looking towards the upstream side of the knife III-III Cross section through the knife IV-IV Cross section through a solid knife bar

Claims (10)

1. A ring knife (10) for multipart cutting units (54) of comminution machines, said cutting units comprising stationary breaker plates (50, 52) and at least one rotating knife (10), in particular for meat mincers and the like,
   comprising a knife body having an inflow side and an outflow side and having a hub (20) and an outer ring (24) as well as a plurality of full knife bars (22) which extend between the hub (20) and the outer ring (24), which carry knife blades (26, 28) and which, together with the outer ring (24) and the hub (20), bound knife spaces (34) and also part knife bars (36) which likewise carry knife blades (38) and which extend into the knife spaces (34) starting from the outer ring (24),
   characterised in that
   the number of the active knife blades (26, 38) disposed at the outflow side is larger than the number of active knife blades (28) disposed at the inflow side; and
   in that the knife spaces (34) expand in the direction (18) of the throughflow of the knife body (10).
2. A ring knife in accordance with claim 1,
   characterised in that
   at least some of the full knife bars (22) have a cross-section reducing towards their outflow side starting from a largest dimension (46) of their cross-section at the inflow side.
3. A ring knife in accordance with claim 1 or claim 2,
   characterised in that
   at least some of the part knife bars (36) have a cross-section reducing over their length starting from the outer ring (24).
4. A ring knife in accordance with claim 3,
   characterised in that
   the boundary surfaces of the part knife bars (36) at the inflow side are spaced apart with respect to the knife plane (40) at the inflow side formed by the cutting edges of the knife blades (28) of the full knife bars (22) at the inflow side and are in particular inwardly increasingly spaced apart from the outer ring (24).
5. A ring knife in accordance with any one of the claims 1 to 4,
   characterised in that
   the preferably conical expansion of the knife spaces (34) is formed by wall slants (30) of the full knife bars (22) or part knife bars (36) and/or by the outer ring (24) or the hub (20).
6. A ring knife in accordance with any one of the claims 1 to 5,
   characterised in that
   the full knife bars (22) and/ or the part knife bars (36) are chamfered on the side at the rear in the direction of rotation (16) of the knife.
7. A ring knife in accordance with any one of the claims 1 to 6,
   characterised in that
   the knife body comprises two part knife bodies adjacent to one another and the one part knife body carries the knife blades forming the knife plane at the inflow side and the other part knife body carries the knife blades forming the knife plane at the outflow side.
8. An apparatus for comminuting foods, in particular for comminuting meat and the like, having at least one breaker plate ring knife cutting unit (54),
   characterised in that
   the outflow side of a ring knife (10) in accordance with one or more of the claims 1 to 7 is associated with the inflow side of at least one breaker plate (52).
9. An apparatus in accordance with claim 8,
   characterised in that
   the ring knife (10) is rotatingly arranged between two stationary breaker plates (50, 52), with the breaker plate (52) at the outflow side having a larger number of holes (58) and smaller holes (58) than the breaker plate (50) at the inflow side.
10. An apparatus in accordance with claim 9,
    characterised in that
    the hole size and the number of holes of the breaker plate (52) at the outflow side and the associated number of knife blades and the number of knives are coordinated in dependence on the properties of the material to be processed such that substantially simultaneous shearing cuts take place over the total breaker plate surface.

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