EP2529834B1 - Drum cutting machine and blade basket for such a machine - Google Patents

Description

The invention relates to a drum cutting machine with a rotary drum. The lateral surface of the rotary drum is provided with a plurality of holes. Along the contour of the rotary drum a plurality of knives is arranged. The invention also relates to a knife basket for such a drum cutting machine.

Such machines are used to crush cereal grains. The cereal grains are introduced into the interior of the rotary drum and move through the holes provided in the lateral surface of the rotary drum to the outside. In the immediate vicinity of the lateral surface of the rotary drum, the blades are arranged. Once a grain protrudes outward beyond the bore, it hits the rotation drum of the drum on one of the knives, so that a part of the grain is cut off. A drum cutting machine according to the preamble of claim 1 is made US 792 485 A known.

For proper operation, it is important that the knives are accurately positioned relative to the rotary drum. In the previous drum cutting machines for a knife basket is provided, which is roughly adapted in shape to the contour of the rotary drum. The exact position of the knives is defined by chocks. The positioning of the chocks and the attachment of the knives requires a fine adjustment, which in consuming Handwork done. Since the fine adjustment must be carried out individually for each knife, high overall effort.

The invention is based on the object to present a drum cutting machine, in which the maintenance is reduced. The object is achieved with the features of claim 1.

This has the advantage that a single support member is provided, over which the position of multiple knives is defined directly. The attachment of the knife to the support member requires no more fine adjustment by a qualified technician, but becomes a simple artisanal activity.

A support member is regularly insufficient to keep the knife safe. Preferably, therefore, a second support member is provided which also has an attachment point defining the position of the cutting edge for each of the knives. Each of the support parts may be arranged adjacent to one of the end faces of the rotary drum. The knives may then extend along the rotary drum from the first support member to the second support member.

The support member may be configured so that the cutting edge of the knife rests against the abutment point. However, then the orientation of the entire knife changes when the cutting edge is deformed in the area of the contact point. In a preferred embodiment, the support part therefore two points of attachment for each knife. The two contact points can engage on different surfaces of the knife, for example on the two surfaces which adjoin the cutting edge. The position of the cutting edge in the support member is then determined not by the cutting edge itself but by the surfaces adjacent the cutting edge.

The two surfaces of the knife, on which rest the two contact surfaces of the support member, are the surfaces adjacent to the cutting edge. Since it is not easy to exactly reproduce the sharp cutting edge of the blade in the support member, the abutment surfaces preferably do not extend directly to the cutting edge. This means that there is no contact between the contact surfaces and the knife in the immediate vicinity of the cutting edge.

For attachment of the blades to the support member, the support member may have an undercut in the radial direction. With a suitable attachment means, such as a screw which engages behind the undercut, the knife can be pulled against the support member and thereby fixed.

In an advantageous embodiment, the support member has an elongated undercut which extends substantially parallel to the contour of the rotary drum. The undercut then forms a rail, along which the fastening means can be guided in a suitable position for the attachment of a knife. At this point, the fastener is stretched.

For the attachment of the support member to the machine, it is advantageous if the support member is an element of a structural component, which can be connected in its entirety with the machine. Preferably, the structural component of two side plates and an intermediate plate, wherein at least one of the side plates is formed as a support member according to the invention. When each of the side plates has an undercut and the side plates are held by the intermediate plate at an appropriate distance from each other, the fastening means can be supported on both undercuts simultaneously and extend between the two side plates in the direction of the blade.

The knives should be aligned so that they extend parallel to the axis of the rotary drum and that the cutting edges have the smallest possible distance to the lateral surface of the rotary drum. The distance may be, for example, between 0.1 mm and 0.2 mm. For example, at least 10, preferably at least 20, knives may be associated with a rotary drum. The support member has contact points for each of the knives which define the position of the cutting edge. The knives are arranged close to each other and can be found in the Sum over a circumferential angle of the rotary drum of at least 45 °, preferably at least 90 °, more preferably at least 135 ° extend. An extension over a circumferential angle of more than 240 ° is usually not desired. In the operating state of the drum cutting machine, the blades are arranged predominantly below the rotary drum. The drum cutter may be equipped with more than one rotary drum. The plurality of rotary drums may be driven by a common shaft.

Depending on the intended use, different sizes of the fragments produced by the drum cutting machine are desired. In general, three sizes are distinguished, namely fine cut, middle cut and rough cut. The fine cuts produce the smallest fragments, the coarse cut the largest fragments. The size of the debris depends on how far the kernel can move out of the well after separating the previous debris before striking the next knife. This depends on how the back surface of the knife facing the rotary drum is aligned. After separation of the previous fragment, the remaining grain is guided on the back surface of the respective knife. Depending on the angle of attack of the back surface, the cereal grain may more or less exit the bore before it encounters the next knife. If the back surface is aligned almost parallel to the outer surface of the rotary drum, the grain can move only slightly and there are small fragments. If the angle of attack is greater, larger fragments will result. Angling angle means that the distance between the rotary drum and the back surface increases the further you move away from the cutting edge.

In order to produce fragments of uniform size, the support parts should be arranged so that the cutting edges on all knives have the same distance from the rotary drum. In addition, the angle of attack should be the same for all knives. For example, the angle of attack between 2 ° and 15 °, preferably between 3 ° and 12 °. The smaller angles within this range lead to a fine cut, the larger angles to a rough cut.

In order to enable rapid conversion of the drum cutting machine between fine cut, center cut and rough cut, the drum cutting machine can be equipped with a knife basket, which can be easily replaced as a unit. The knife basket comprises two support parts and a plurality of knives attached to the support parts, the knives being fixed in the positions defined by the abutment points of the support parts. In an advantageous embodiment, the drum cutting machine comprises a set of knife baskets, wherein the knives of the different knife baskets have different angles of incidence. For example, the kit may include a first knife basket for fine-cut where the angle of attack is between 2 ° and 5 °. For a second knife basket intended for the middle cut, the angle of attack can be between 5 ° and 8 °. For a third knife basket for rough cutting, the angle of attack can be between 9 ° and 12 °.

The invention also relates to a knife basket for such a drum cutting machine. The knife basket includes two Support members, which are arranged in a matched to the rotary drum distance from each other, and a plurality of knives, which are respectively secured to the two support members and whose position is defined by contact points of the support members. The knife basket can be combined with other features described above with reference to the drum cutting machine according to the invention.

Fig. 1:

eine schematische Schnittansicht einer erfindungsgemä- ßen Trommelschneidemaschine;

Fig. 2:

eine Draufsicht auf einen erfindungsgemäßen Messerkorb;

Fig. 3:

einen vergrößerten Ausschnitt aus Fig. 2;

Fig. 4:

ein Detail eines Messerkorbs in Schnittdarstellung;

Fig. 5:

eine schematische Darstellung einer Drehtrommel und eines Messers; und

Fig. 6:

einen Ausschnitt aus einem Stützteil mit einem Messer.

The invention will now be described by way of example with reference to the accompanying drawings with reference to an advantageous embodiment. Show it:

Fig. 1:

a schematic sectional view of a drum cutting machine according to the invention;

Fig. 2:

a plan view of a knife basket according to the invention;

3:

an enlarged section Fig. 2 ;

4:

a detail of a knife basket in sectional view;

Fig. 5:

a schematic representation of a rotary drum and a knife; and

Fig. 6:

a section of a support member with a knife.

In a drum cutting machine in Fig. 1 a shaft 15 is rotatably mounted in a machine housing 16. On the shaft 15, two rotary drums 14 are fixed, whose lateral surfaces are provided with a plurality of holes 17. The diameter of the holes 17 is selected so that cereal grains can pass straight through. Via an electric motor 18, the shaft 15 can be rotated with the rotary drums 14 in rotation. When the machine is in operation, the speed is about 50 rpm.

The lower part of both rotary drums 14 is surrounded by a respective knife basket 18, as in Fig. 2 is shown in perspective view. The knife basket 18 is composed of two structural members 19 to which a plurality of knives 20 are attached. The structural components 19 are arranged parallel to the two end faces of the rotary drum 14 and adapted to the circular contour of the end faces. The knives 20, which extend between the two structural components 19, are held at a small distance from the lateral surface of the rotary drum 14. In this exemplary embodiment, the knife basket 18 comprises thirty knives 20, which are all parallel to one another and are arranged at a small distance from the lateral surface of the rotary drum 14. In total, approximately the lower half of the rotary drum 14 is covered by the knives 20.

Through a nozzle 21 cereal grains can be fed into the interior of the rotary drum 14. By gravity, the grains fall into the lower part of the rotary drum. By the rotation of the rotary drum 14, the cereal grains are kept in motion, so that again and again cereal grains come in the correct position and orientation to enter into one of the holes 17. The cereal grains then move through the holes 17 to the outside until they protrude beyond the lateral surface of the rotary drum 14. By the rotation of the rotary drum 14, the grain is struck against one of the knives 20, so that a part of the grain is cut off. The remaining part of the cereal grain continues to move outwards until contact with one of the knives 20 takes place again further part of the cereal grain is cut off. The fragments of the cereal grains are collected under the rotary drums 14 and transported away for further use.

The schematic representation of Fig. 5 shows a section of the rotary drum 14 with a bore 17 and a arranged under the rotary drum 14 knife 20. The knives 20 are adjusted so that the distance between the cutting edge 28 and the lateral surface of the rotary drum is as small as possible. In practice, the distance, as indicated by the dashed line, is about 1 mm. The angle of attack of the back surface 27 of the blade 20 sets how far the remaining grain can move out of the holes 17 before it encounters the next blade 20. The greater the angle of attack between the rear surface 27 and the tangent line drawn in dashed lines to the rotary drum 14, the greater becomes the fraction of cereal grain separated from the following knife 20. For the drum cutting machine of the embodiment, three knife baskets 18 are provided, in which the inclination angle of the knives 20 is different. In the first, provided for fine cut knife basket 18, the inclination angle is about 4 °. In the second, provided for central cutting knife basket 18, the inclination angle is about 7.5 °. In the third, provided for rough cutting knife basket 18, the inclination angle is about 11 °.

The cutting of the cereal grains takes place only in the lower half of the rotary drum 14. If a cereal grain is still stuck in one of the holes 17 after the area of the knives 20 has been left, the cereal grain falls below it In order to support this, a needle drum may be provided, the needles of which engage in the bores 17 in order to release also stuck cereal grains from the bores 17.

As the Figures 3 and 4 show, the structural component 19 is composed of three components, namely two side plates and an intermediate plate arranged between the side plates 22. The side plates have a substantially semicircular contour corresponding to the lateral surface of the rotary drum 14. In the side plates, a blade receptacle is formed in each case for each of the knives 20, so that the side plates each form a support part 23 in the sense of the invention. As the Fig. 6 shows in an enlarged view, each blade receptacle comprises two contact surfaces 24, 25, one of which rests on the front surface 26 and one on the rear surface 27 of the blade 20. By the contact surfaces 24, 25, both the position of the cutting edge 28 of the knife and the orientation of the front surface 26 and the rear surface 27 is uniquely determined. The contact surfaces 24, 25 do not extend to the cutting edge 28, but keep with a circular recess at a distance.

According to Fig. 4 The support members 23 each have an undercut 30 in the radial direction. By the intermediate plate 22, the support members 23 are held at a distance to each other, which finds an outwardly extending screw with her head to the undercuts 30 support. The screw is passed through a hole in the knife 20 and thus forms a fastening element 29 for the knife 20. The undercuts 30 extend parallel to the contour of the support members 23, so that a rail is formed, along which the screw can be moved. The screw can thereby be tensioned against the knife 20 in any desired position, that is to say in particular in the position predefined by the contact surfaces 24, 25. It is therefore a simple artisanal activity to assemble a knife basket 18 from the supporting parts 23 and the corresponding number of knives 20.

Claims (9)

1. Drum cutting machine having a rotary drum (14) and having a plurality of blades (20) arranged along the contour of the rotary drum (14), the lateral surface of the rotary drum (14) being provided with a multiplicity of holes (17), wherein there is provided a supporting part (23) which matches the contour of the rotary drum (14) and has for each of the blades (20) two bearing surfaces (24, 25) that define the position of the cutting edge, characterized in that there is planar contact between the bearing surfaces (24, 25) and the two surfaces (26, 27) adjoining the cutting edge, of the blade (20).
2. Drum cutting machine according to Claim 1, characterized in that there are provided two supporting parts (23), and in that the supporting parts (23) are arranged adjacently to the end faces of the rotary drum (14).
3. Drum cutting machine according to Claim 1 or 2, characterized in that there is no contact with the bearing surfaces (24, 25) in a part of the surfaces (26, 27) that directly adjoins the cutting edge (28).
4. Drum cutting machine according to one of Claims 1 to 3, characterized in that the supporting part (23) has an undercut (30) in the radial direction, a fastening element (29) of a blade engaging behind said undercut (30).
5. Drum cutting machine according to Claim 4, characterized in that the undercut (30) extends parallel to the contour of the rotary drum (14).
6. Drum cutting machine according to one of Claims 1 to 5, characterized in that the supporting part (23) is a component of a structural element (19) composed of two side plates and an intermediate plate (22), the side plates being held at a distance from one another by the intermediate plate (22).
7. Drum cutting machine according to one of Claims 1 to 6, characterized in that there is provided a blade box (18) which is exchangeable as a unit and comprises the supporting part (23) and also the blades (20) fastened thereto.
8. Drum cutting machine according to Claim 7, characterized in that a set of blade boxes (18) to be used alternately is provided, the blades (20) of the different blade boxes (18) having different inclination angles.
9. Blade box for a drum cutting machine, having two supporting parts (23) which match the contour of the rotary drum (14) of a drum cutting machine and which are arranged at a distance from one another that matches the length of the rotary drum (14), and having a plurality of blades (20), which are each fastened to the two supporting parts (23), wherein each of the supporting parts (23) has two bearing surfaces (24, 25) that define the position of the cutting edge, characterized in that there is planar contact between the bearing surfaces (24, 25) and the two surfaces (26, 27) adjoining the cutting edge, of the blade (20).

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