DE29800868U1 - Round knife - Google Patents

Description

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PALGEN, SCHUMACHER & KLUIN

DÜSSELDORF ESSEN PATENT ATTORNEYS

OUR REGISTRATION: 97 1064 P/rm. Düsseldorf, 19 January 1998

FILE NO. 6

RASSPE INTERNATIONAL

GMBH & CO. KG

Sticks 17

D-42651 Solingen

Round knife

The invention relates to a circular knife of the type corresponding to the preamble of claim 1.

The term "circular knife" is intended to include, on the one hand, circular disk-shaped knives in which the cutting edge or (in the case of serrated cutting edges) the envelope curve of the cutting edge is a circle coaxial with the axis of the circular disk that forms the axis of rotation (DE 40 31 671 C2 or DE-GM 71 16 979). On the other hand, however, it is also intended to include rotating knives in which the radius of the cutting edge is not constant over the circumference, such as in the case of a spiral knife (DE 38 33 596 C2 or US-PS 1 957 623).

Such circular knives are used in cutting machines for cheese and the like, which are used in the private sector, but mainly in the commercial and industrial sector, e.g. delicatessens, supermarkets and especially in cheese factories, to produce sliced portions of cut product.

The circular knives are usually in a fixed

Housing is rotatably mounted, and the cut material is moved on a vertically to the rotation axis of the circular blade

D40239 DÜSSELDORF MULVANYSTRASSE 2 TELEPHONE 49 / 211 / 96 145 - 0 FAX 49 / 211 / 96 145 - 20 D-45133 ESSEN FRÜHLINGSTRASSE 43 A TELEPHONE 49 / 201 / 84 230 - 0 FAX 49 /201/84 230 - 20

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The carriage is guided radially from the outside against the circular blade. In industrial cutting machines, however, the circular blade is also moved perpendicular to its axis of rotation. Only the relative movement is important. The front of the material to be cut rests against a stop surface that extends perpendicular to the axis of rotation. In order to maintain this contact, which is important for the dimensional accuracy of the slices, the material to be cut is pressed with a certain force parallel to the axis of rotation against the contact surface and against the adjacent essentially flat or flat, conical cutting surface of the circular blade.

Sliced cheese has a shape stability, so that it can be handled like bread and pushed forward in the cutting machine. Unlike bread, however, sliced cheese has a stickiness that means it literally sticks to a flat counter surface. For this reason, it is generally ensured that the cutting surface of the cutting surface facing the cheese wheel is not parallel to the cheese wheel, because otherwise it would stick flat to the cheese wheel. This would significantly increase the energy required to drive the circular knife and for the feed and would also lead to deformation of the cheese wheel and completely uneven slices. The cutting surface facing the cheese wheel is instead slightly inclined compared to the cutting surface due to a slight conicity, so that only the actual cutting edge comes into contact with the cheese wheel.

As a further measure to improve the cutting behavior of the circular knives in question when cutting material such as sliced cheese and the like, it is known to provide a toothing on the cutting edge, in which the crests of the toothing follow one another at a distance of one to several centimeters, seen in the circumferential direction.

Even with such circular knives, cuttings such as sliced cheese and the like remain particularly in continuous use.

operation, as it occurs particularly in the industrial sector, problematic.

The invention is based on the object of designing a generic circular knife in such a way that its cutting properties are improved.

This object is solved by the invention set out in claim 1.

It has been shown that with a fine round-arch toothing, where the crests of the individual teeth are only a few millimeters apart, a significant improvement in the cutting properties can be observed.

Possible dimensions of the "fine round-arch toothing" are given in claims 2 to 5.

An important further development of the invention is the subject of claims 6 and 7.

The spaces between the teeth expand in a funnel shape towards the side away from the material being cut. This has the effect that when cutting from the side of the material being cut, material that has penetrated between the teeth can easily move away from the material being cut because the flow cross-section expands in this direction and no pressure builds up that could counteract the outward movement. In this way, the round-arch toothing is self-cleaning and permanently retains its cutting properties because the teeth do not become clogged.

For manufacturing reasons, it is recommended that the angle of the base of the interdental spaces to the cutting surface on the cutting material side is 30 to 60° (claim 7).

In this way, the spaces between the teeth can be created using a grinding or milling tool that can be rotated around an axis that is located slightly to the side of the circular blade and approximately tangential to it.

An important design for the practical usability of the circular knife is the combination of the curved toothing with a friction and/or wear-reducing coating made of polytetrafluoroethylene, chromium or hard materials according to claim 8, at least in its area.

An embodiment of the invention is shown in the drawing.

Fig. 1 shows a view of a circular knife from the side facing away from the material to be cut;

Fig. 2 shows a section through the axis through the upper half of Fig. 1 on an enlarged scale;

Fig. 3 shows a greatly enlarged view of the round-arch gearing;

Fig. 4 shows a section along the line IV-IV in Fig. 3;

Fig. 5 shows a section along the line V-V in Fig. 3.

The circular knife, designated as a whole with 100 in Fig. 1, is used to cut sliced cheese into slices and has a circular disk-shaped knife body 1 made of a suitable steel with a central centering hole 2, with which the circular knife 100 is placed on the shaft or knife holder of the cutting machine. The circular knife is attached by means of four screws distributed around the circumference, which are screwed into the holes 3, and can then rotate around the axis A of the circular disk.

As can be seen from Fig. 2, the circular knife 100 is not flat, but rather dished into a flat-conical disk, which has a ground cutting bevel 4 on the outer edge with a cutting circle 8 concentric with the axis A. The inner edge of the cutting bevel 4 is designated 4'.

The pushing side of the circular knife 100, i.e. the side on which the cheese wheel is located, from the slices

The concave side is the one on which the material is to be cut off and is marked by the arrow 5 in Fig. 2. On the push side 5, a circumferential shoulder 9' is provided, i.e. the middle part of the knife is set back slightly. Radially outside the shoulder 9', a slightly conical cutting surface 9 is provided facing the material to be cut, forming an angle 21 of approximately 5° with a plane E perpendicular to the axis A. On the opposite side, the circular knife 100 has a groove 6 running around the circumference with an edge 7, from which the thickness of the knife body 1 decreases towards the cutting bevel 4.

The cutting edge is formed by a round-arch toothing 10, the enveloping circle of which is the cutting circle 8. The round-arch toothing 10 is shown in Fig. 1 only on a small part of the circumference and enlarged in Fig. 3. It is understood, however, that the round-arch toothing 10 actually extends evenly over the entire circumference. The cutting edge is formed by individual teeth 11 with vertices 12. The teeth 11 essentially have the shape of isosceles triangles, the base of which sits on the knife body 1 and the tip of which is rounded off by a round arch 13. In the exemplary embodiment, the round arch has a radius 14 of approximately 0.5 mm. The sides 15, 16 of the teeth 11 that merge tangentially into the round arch 13 enclose an angle 17 with one another, which in the exemplary embodiment is approximately 80°. The radial height 18 from the base 19 of the individual tooth space 20 to the crests 12 or the cutting circle 8 is 1.5 mm.

A radius is also provided at the base 19 of the interdental spaces, but it is smaller than the radius 14 and is only present for manufacturing reasons.

The dimensions described can be found on the cutting surface 9, which faces the material to be cut. On the opposite side is the lateral limit

the inter-tooth spaces 20 are somewhat different because the inter-tooth spaces 20 diverge towards this side, as can be seen from Fig. 3. This increases the flow cross-section of the inter-tooth spaces away from the cuttings. Thus, no pressure builds up for cuttings entering the inter-tooth spaces 20 from the pushing side 5 as it flows through the inter-tooth spaces 20 parallel to the axis A, and the inter-tooth spaces 20 do not become clogged by such cuttings.

The teeth 11 are produced by milling or grinding. The tool circumference W can be seen in Fig. 4. The connecting line from the lower vertex 19 to the lower vertex 19' at the bottom of the respective tooth gap 20 is therefore not a straight line, but a circular section with a relatively large radius. The line slopes down towards the side facing away from the material to be cut. A tangent T placed approximately in the middle forms an angle 23 of approximately 45° with the side surface 9.

The circular blade 100 can have a friction and/or wear-reducing coating with polytetrafluoroethylene, chromium or a similar plastic and/or a hard material in the area of the round-arch toothing 10 and also in other areas that come into contact with the material to be cut.

Claims (8)

PALGEN, SCHUMACHER·^fcL'UlN·' ·:· ··"··" DÜSSELDORF ESSEN PATENT ATTORNEYS OUR SIGN: 97 1064 P/rm. D&agr;sse&igr;d&ogr;rf.den 19. Januar 1998 FILE NO. 6 RASSPE INTERNATIONAL GMBH & CO. KG Stöcken 17 D - 42651 Solingen Protection claims 1. Circular knife (100) for cutting material such as cheese and the like from a loaf into slices, with a disk-shaped knife body (1) with a cutting edge provided with teeth on the circumference, which is limited on the side of the material to be cut by a substantially flat or flat conical cutting surface (9) and on the opposite side by a cutting surface (6) milled at the edge towards the cutting circle (8),
characterized, that the cutting edge has a fine round-arch toothing (10). 2. Circular knife according to claim 1, characterized in net that the round-arch toothing on the side of the material to be cut has a radial height (18) of 1 to 3 mm from the base (19) of the tooth spaces (20) to the apex (12). 3. Circular knife according to claim 1 or 2, characterized in that the distance (22) between the bases (19) of the tooth D-40239 DÜSSELDORF MULVANYSTRASSE 2 TELEPHONE 49 / 211 / 96 145 - 0 FAX 49 / 211 / 96 145 - 20 D-45133 ESSEN FRÜHLINGSTRASSE 43 A TELEPHONE 49 / 201 / 84 230 - 0 FAX 49 /201/84 230 - 20 POSTBANK COLOGNE (bank code 370 100 50) 115 211 - 504 spaces (20) from each other in the circumferential direction is 2 to 4 mm. 4. Circular knife according to one of claims 1 to 3, characterized in that the tooth flanks (15, 16) of a tooth (11) on the side of the material to be cut form an angle (17) of 60° to 100° to one another. 5. Circular knife according to one of claims 1 to 4, characterized in that the radius (14) of the round arc (13) on the side of the material to be cut is 0.3 to 1.5 mm. 6. Circular knife according to one of claims 1 to 5, characterized in that the boundaries of the interdental spaces (20) diverge across the thickness of the knife body (1) towards the side facing away from the material to be cut. 7. Circular knife according to claim 6, characterized in that the angle (23) of the base of the tooth spaces (20) to the cutting surface (9) on the material to be cut side is 30° to 60°. 8. Circular knife according to one of claims 1 to 7, characterized in that the knife body has a friction and/or wear-reducing coating at least in the cutting area.