EP2072196B1 - Slide rail guide for a cutting machine - Google Patents

Abstract

An enclosure (1) for blades has an enclosure frame (6) for clamping the blades and a holder frame (7) for releasable linkage of the enclosure for blades to a feeder area on a foodstuff machine. The enclosure frame is placed in bores of bearings (9) in the holder frame so as to slide with sliding rods (8). The outer surface area of each sliding rod is formed in sections by a bearing bush (10) fitted so that only the bearing bushes of the sliding rods make contact with inner surface areas of the bores of bearings.

Description

introduction

The invention relates to a machine for cutting food into slices, strips or cubes, with a feed region from which the food is conveyed by means of a feed device to a cutting device, the at least one linearly oscillating movable knife gate having a plurality of elongated, parallel with Having spaced apart gate knives, wherein the at least one knife gate has a gate frame for clamping the gate blade and a holding frame for releasably connecting the knife gate with the feed of the machine and wherein the gate frame is slidingly mounted with sliding rods in bearing bores in the holding frame.

State of the art

Such cutting machines are for example from the publications DE 1247572 B and DE 29823832 U1 known. Often, such machines are designed as so-called dicing machines in which strand-shaped or present in the form of large pieces food in an elongated, the feed area forming insertion, a so-called magazine, are inserted. With the aid of a hydraulically driven extrusion punch of a feed device, the material to be cut is fed through an exit cross section of the feed region onto the cutting device. The cutting device consists of a first knife gate (subgrid), which initially cuts slices from the food. By means of a subgatter downstream second knife gate (top gate), whose gate blades are perpendicular to the gate blades of the subgatter, are cut from the slices of strips, typically with a square cross-section. Finally, located in the plane of the backs of the gate blade of the upper gate a rotating cutting blade, with the successive cube or cuboid are cut from the emerging from the upper gate food strip.

In the known machines, the slide bars of the gate frame made of stainless steel and are guided in bushings, which are arranged in the bearing bores in the respectively associated holding frame. The bushings are pressed into the bearing bores to ensure sufficient fixation in the axial direction. For a long time exist the bushings typically made of polytetrafluoroethylene (PTFE) to obtain a low-friction and low-wear friction pairing.

However, the PTFE material used has since turned out to pose a health concern. It is suspected that the material wear on the bushings, which forms almost inevitably in connection with the fats contained in the food a kind of dark smear and may also get into the cut food, the risk of cancer is increased when consuming such contaminated food , Although other plastic materials are known that are considered harmless in terms of health. However, these plastics do not have the excellent wear characteristics inherent in PTFE. Nevertheless, if plastic materials with worse wear properties were used, a correspondingly frequent replacement of worn bearing bushes would be necessary. This replacement operation is typically not carried out by the user of such a machine, since the bearing bush requires very great effort, i. typically using a hydraulic press, must be pressed out of the bearing bore in the support frame and in turn must be replaced by a pressing operation by a new bearing bush.

task

The invention has for its object to further develop a machine for cutting food with at least one Gattermesser to the effect that the exchange of worn bushings is significantly improved against new, in order in this way also health-safe materials for the bushings □ with the result of shortened change intervals □ to use.

solution

Starting from a machine of the type described above, the above-mentioned object is achieved in that the outer surface of each slide bar is at least partially formed by at least one arranged bushing that in the oscillating movement of the slide rods only their bushings with the respective inner circumferential surface of the bearing bores Holding frame come into contact.

According to the invention, therefore, the bearing material, which is characterized by its special sliding properties, no longer used to order the inner surface of the To form bearing bore in the support frame. Rather, the bearing bore can now have a simple metallic jacket surface and be formed by the base material of the holding frame, which is typically made of stainless steel. In contrast, according to the inventive idea, the outer surface of the slide bar is provided with the bearing material possessing the special sliding properties. So that when a wear limit of this material in a simple manner replacement can be carried out with further use of the slide bar itself, at least one bearing bush is pushed onto the slide bar, which forms the outer surface of the slide bar. This outer circumferential surface slidably cooperates with the inner (metallic) lateral surface of the bearing bore of the holding frame. Basically, it is possible to provide the slide bar over its entire (free) length with a single or more directly abutting bushing (s). To avoid deformations too long bushings, however, it will be sin n-full in most cases, provide two spatially spaced bearing bushes and to determine their position and length so that in the oscillating movement of the sliding rods only the bearing bushes (and not the remaining possibly metallic portions of the slide bar) come into contact with the respective lateral surfaces of the bearing bores of the holding frame. The minimum length of a bearing bush corresponds to the principle of the invention "outer sleeve" thus the sum of the axial length of the bearing bore in the holding frame and the stroke of the gate movement. In practice, the aforementioned minimum length will be slightly exceeded for safety reasons.

Even if according to the principle of the present invention, the bushings longer than in the prior art machines must be performed and therefore tends to greater material consumption, this is more than compensated by the ease when changing the bushings: The "outer bushes" according to the invention can namely simply in axial Toward the sliding bar, which forms a typically metallic core in this area, be postponed. In this case, it is not necessary to produce a press fit which can be accomplished only with the aid of special tools, but typically a transition fit is selected between the inner diameter of the bearing bush and the outer diameter of the sliding rod section there, so that a slight clearance fit or a slight interference fit results in practice. which should allow a simple and tool-free removal of the bearing bush in any case. In the worst case, the bearing bush can be removed by means of a pair of pliers or cut by a knife in the axial direction and then removed from the slide bar. Nevertheless, if a solid press fit is desired and replacement is required, it can be quickly and easily use a new slide with already finished pressed bushing, and the old slide can be provided in the meantime in a workshop with the required tool with a new bushing , This significantly reduces the time in which the cutting machine stands still due to the replacement of the bearing bushes.

In the machine in which the idea according to the invention is realized, it may be one with only one knife gate, but preferably one with two knife gates (top gate and sub-gate), so that the advantage of easy replacement due to the then usually needed eight bushings is particularly large. In most cases, the upper gate is followed by a cut-off knife, which is rotatable in a plane perpendicular to a feed direction and parallel to a plane of the knife gate in order to produce cutting cube.

Preferably, each gate frame on two sliding rods, each with its end portions positively on the one hand in a drive traverse of the gate frame, which is frictionally coupled with an eccentric of a drive shaft of the machine, and on the other hand can be used in a tension traverse, which can be braced with a tensionable by means of bolts clamping block for bracing the gate blade is provided in the gate frame. The insertion of the end portions of the slide rods in the respective cross member of the gate frame should be done with a slight clearance fit to easily disassemble the gate frame for the purpose of replacing the bearing bushes.

In terms of design, it is particularly favorable if each slide bar has a middle section, to which a seat section adjoins at both ends of the slide bar whose outer diameter is smaller than the outer diameter of the central section, wherein the outer diameter of the seat section corresponds to the inner diameter of the bearing bushes. With two separate bushings per slide bar is provided by the central portion a reliable positioning or securing the bearing bush against displacement in the direction of the center of the slide bar.

In order to achieve a simple fixation in the opposite direction, may adjoin each seat portion to the respectively associated end of the slide bar out a fixing, whose outer diameter is smaller than the outer diameter of the seat portion, wherein the outer diameter of the fixing portion of the inner diameter of a fixing sleeve corresponds, which is supported with one end face on a facing end face of the bearing bush and with the other end face on the drive traverse or the tension traverse. After the assembly of the bushings takes place in a first step by sliding from the end faces of the slide bar ago in a next step, the sliding of the Fixierhülsen, which have a transition fit or a slight clearance with respect to the fixing. The radial clearance can be dimensioned somewhat larger in the region of the fixing sleeves than in the region of the bearing bush, since the latter also have to transmit radial forces as far as possible without deformation to the core of the sliding rod. The Fixierhülsen itself need not be secured by a separate component against axial displacement, but it is particularly advantageous to fix both bushings and both Fixierhülsen during clamping of the knife by the then strained braces.

• dem Endabschnitt und dem Fixierabschnitt der Gleitstange,
• dem Fixierabschnitt und dem Sitzabschnitt der Gleitstange und/oder
• dem Sitzabschnitt und dem Mittelabschnitt der Gleitstange.

The invention further ausgestaltend is provided, each form a radial step between

• the end portion and the fixing portion of the slide bar,
• the fixing portion and the seat portion of the slide bar and / or
• the seat portion and the middle portion of the slide bar.

In order to obtain a visually particularly pleasing and against contamination at edges unmanageable Gleitstangengeometrie, the outer diameter of the central portion of the slide should correspond to the outer diameter of the bearing bush and / or the outer diameter of the fixing sleeve.

While the outer surface of the bearing bores in the holding frame and the holding frame itself made of stainless steel, the bushings should be made of a harmless plastic material, in particular polypropylene (PP) or polyoxymethylene (POM), or from a metal sleeve with a coating of a silicon Carbide ceramic (SiC ceramic) to be made. These materials are physiologically harmless, resistant to many chemical reagents and have to many other materials a comparatively high abrasion resistance with good sliding properties. In contrast, the Fixierhülsen, which do not have to have corresponding properties, made of stainless steel.

embodiment

The invention will be explained in more detail below with reference to an embodiment of two knife gates of a cutting machine not shown in its entirety, but known from the prior art from its basic structure forth with reference to the accompanying drawings.

Fig. 1:

eine perspektivische Ansicht eines ersten Messergatters (Untergatter),

Fig. 2:

eine perspektivische Ansicht eines zweiten Messergatters (Obergatter),

Fig. 3:

eine Draufsicht auf das Untergatter gemäß Figur 1,

Fig. 4:

eine Draufsicht auf das Obergatter gemäß Figur 2,

Fig. 5:

einen Schnitt durch das Untergatter gemäß Figur 3 entlang der Linie V-V,

Fig. 6:

eine Detailansicht eines Abschnitts einer Gleitstange des Untergatters gemäß Figur 3,

Fig. 7:

einen Schnitt durch das Obergatter gemäß Figur 4 entlang der Linie VII- VII und

Fig. 8:

eine Detailansicht eines Abschnitts einer Gleitstange des Obergatters gemäß Figur 4.

It shows:

Fig. 1:

a perspective view of a first knife gate (subgrid),

Fig. 2:

a perspective view of a second knife gate (upper gate),

3:

a plan view of the subgatter according to FIG. 1 .

4:

a plan view of the upper gate according to FIG. 2 .

Fig. 5:

a section through the subgrid according to FIG. 3 along the line VV,

Fig. 6:

a detailed view of a portion of a slide bar of the subgatter according to FIG. 3 .

Fig. 7:

a section through the upper gate according to FIG. 4 along the line VII-VII and

Fig. 8:

a detailed view of a portion of a sliding bar of the upper gate according to FIG. 4 ,

A not shown, but in terms of its basic structure known dicing machine is in the region of an outlet cross section of a magazine for filling with the food to be cut with a first knife gate 1 (subgatter) and a second knife gate 2 (top gate), in the Figures 1 and 2 are shown in perspective, equipped. In a known manner, the attachment of the knife gate 1, 2 by means of screws, the holes 3 in a support frame 7 of the upper knife gate 2 and 4 pockets in a support frame 7 of the lower knife gate 1 penetrate and on This way ensure a positive fixation of both knife gates 1, 2 in the region of the magazine outlet cross section of the cutting machine.

In the Figures 3 and 4 are each plan views of the knife gate 1 according to FIG. 1 and on the knife gate 2 according to FIG. 2 shown. A gate frame 6, sit in the gate blade 5 for cutting food, is mounted on two sliding rods 8 movable on the respective, attached via the holes 3 and 4 pockets on the magazine outlet opening holding frame 7. The gate frame 6 consists of the mentioned two slide rods 8, located at one end of the gate frame 6 drive crossmember 12 and sitting on the drive crossmember 12 end of the gate frame 6 Spanntraverse 13. Between the drive crossmember 12 and the crossbeam 13, the gate blade 5 are taut clamped to prevent lateral movements of the individual gate blade 5 as possible and thereby ensure clean cuts. Feeding are the gate blade 5 with its one end in the drive traverse 12, with the other end in a clamping block 14 which is fastened with bolts 18 on the tensioning beam 13 and with the over the bolts 18, the gate blade 5 are braced. The drive crossmember 12 also has a hook-shaped receptacle 17, to which an eccentric pin of a drive shaft of the cutting machine can be frictionally coupled for the cutting movement of the gate frame 6.

A detailed, enlarged view of the existing stainless steel sliding rods 8 is in each case in a section through the knife gate 1 along the line V □ V in FIG. 3 and in a section through the knife gate 2 along the line VII □ VII in FIG. 4 in the Figures 5 and 7 shown. In the middle of the slide rods 8, which move slidably in the bearing frame 7 located bearing bores 9, there is a so-called middle section 15, to each of the two ends of the slide rods 8 successively a seat portion 19, a fixing portion 20 and an end portion 11th connect. According to the individual sections of the slide rods 8, the outer diameter of the slide rods 8 also varies stepwise.

The outer diameter of the central portion 15 corresponds to the outer diameter of bearing bushes 10, which are pushed onto the two adjacent to the central portion 15 seat portions 19. In order to ensure a snug fit of the bushings 10 on the slide bar 8, the seat sections 19 must therefore have a reduced by twice the wall thickness of the bearing bushes 10 outer diameter. The bushings 10 should consist of a low-friction material, but because of the possibly occurring during operation of the cutting machine material abrasion should be harmless to health. In question, for example, the partially crystalline thermoplastics polypropylene (PP) or in particular polyoxymethylene (POM) would come. PP is characterized as a material for the bushings 10 in that it is chemically resistant to almost all polar organic solvents, with respect to alcohols, oils and fats as well as acids and alkalis with good sliding properties and physiological safety. POM, on the other hand, has a high hardness and a very low coefficient of friction over a wide temperature range, in addition to a similar chemical resistance to the chemicals mentioned above. In addition, it has an extremely good dimensional stability, making it predestined for use as a material for moving precision parts. For cleaning of cutting machines, water is used at very high temperatures due to the pollution caused by the fats occurring in the food to ensure the required hygiene. Due to the great dimensional stability of POM over a long period of time at temperatures up to 110 ° C or for a short time up to 150 ° C, this plastic is ideal as a material for the bearing bushes 10 of the slide rods. 8

As an alternative to plastic as a socket material, it is also possible to produce the bearing bushes 10 from a metal sleeve with a coating of, for example, a silicon carbide ceramic (SiC ceramic). SiC ceramics are known for their high abrasion resistance and are often used in industry for plain bearings. It also has a high resistance to organic solvents and strong acids and is physiologically harmless.

The adjoining the seat portions 19 Fixierabschnitte 20 have a reduced compared to the diameter of the seat portions 19 outer diameter and are used to hold Fixierhülsen 16. These stainless steel Fixierhülsen 16 whose outer diameter corresponds to that of the central portion 15 and the bearing bushes 10, abut the end face with its one end once to the bushings 10 and with its other end to the drive beam 12 and the tensioning spreader 13 at. Thus, the bearing bushes 10 moving in the bearing bores 9 are clamped between the middle section 15 and the fixing sleeves 16. The length of the bearing bushes 10 should at least the length of the bearing holes 9 plus the path length on which the gate frame 6 executes the cutting movement, that is plus the so-called Gateshubs correspond. The length of the Fixierhülsen 16 is chosen so that it bridges the remaining distance between the bushings 10 and the respective associated end portions 11 accurately.

For holding the slide rods 8 on the gate frame 6 are in the drive beam 12 and the clamping beam 13 holes for positive reception of the respective end portions 11 of the slide rods 8, whose diameter is reduced compared to the diameter of the fixing portions 20 again.

In the FIGS. 6 and 8th is, also enlarged, the respective portion of the knife gate 1 denoted by VI or VIII FIG. 3 or the knife gate 2 off FIG. 4 shown. It can be seen here by way of example, as the fixing sleeve 16, accurately inserted between the bearing bush 10 and the drive beam 12, the end face on the end of the slide bar 8 side towards the drive beam 12 and on the middle section 15 side towards the bearing bush 10 is supported. Of course, the same also applies to the side of the knife gate 1 or knife gate 2, on which the tensioning traverse 13 is located.

LIST OF REFERENCE NUMBERS

1

knife gate

2

knife gate

3

drilling

4

bag

5

reciprocating knife

6

gate frame

7

holding frame

8th

sliding bars

9

bearing bore

10

bearing bush

11

end

12

drive Traverse

13

tensioning traverse

14

clamping block

15

midsection

16

fixing sleeve

17

admission

18

bolt

19

seat section

20

fixing

Claims (10)

1. Machine for cutting foods into slices, strips or cubes, with a feed region from where the food can be conveyed by means of a feed device to a cutting device, which has at least one blade grid (1, 2) which can be moved in a linearly oscillating manner and has a plurality of elongate grid blades (5) which are arranged in parallel at a distance from each other, wherein the at least one blade grid (1, 2) has a grid frame (6) for clamping the grid blades (5) and a retaining frame (7) for releasably connecting the blade grid (1, 2) to the feed region of the machine, and wherein the grid frame (6) is mounted in a sliding manner in mounting bores (9) in the retaining frame (7) with sliding rods (8), characterised in that the outer circumferential face of each sliding rod (8) is formed at least in sections by at least one mounting bushing (10) which is arranged in such a manner that when the sliding rods (8) move in an oscillating manner only their mounting bushings (10) come into contact with the respective inner circumferential face of the mounting bores (9) of the retaining frame (7).
2. Machine according to Claim 1, characterised by a cutting blade which can be rotated in a plane perpendicular to a feed direction and parallel to a plane of the blade grid (1, 2).
3. Machine according to Claim 1 or 2, characterised in that the grid frame (6) has two sliding rods (8) which can be inserted in each case with their end sections (11) in a form-fitting manner at one end into a drive crossmember (12) of the grid frame (6), which can be coupled in a force-fitting manner to an eccentric pin of a drive shaft of the machine, and on the other side into a clamping crossbeam (13) which is provided with a clamping block (14), which can be clamped by means of bolts (18), for clamping the grid blades (5) in the grid frame (6).
4. Machine according to one of Claims 1 to 3, characterised in that each sliding rod (8) has a central section (15) to which towards both ends of the sliding rod (8) in each case one seat section (19) is attached, the outer diameter of the seat section (19) is smaller than the outer diameter of the central section (15), wherein the outer diameter of the seat section (19) corresponds to the inner diameter of the mounting bushings (10).
5. Machine according to Claim 4, characterised in that a fixing section (20) is attached to each seat section (19) towards the respectively associated end of the sliding rod (8), the outer diameter of which fixing section (20) is smaller than the outer diameter of the seat section (19), wherein the outer diameter of the fixing section (20) corresponds to the inner diameter of a fixing sleeve (16) which is supported with one end face on an end face facing it of the mounting bushing (10) and with the other end face on the drive crossbeam (12) or the clamping crossbeam (13).
6. Machine according to Claim 4 or 5, characterised by in each case a radial step between

   - the end section (11) and the fixing section (20) of the sliding rod (8),

   - the fixing section (20) and the seat section (19) of the sliding rod (8) and/or

   - the seat section (19) and the central section (15) of the sliding rod (8).
7. Machine according to Claim 5 or 6, characterised in that the outer diameter of the central section (15) of the sliding rod (8) corresponds to the outer diameter of the mounting bushing (10) and/or to the outer diameter of the fixing sleeve (16).
8. Machine according to one of Claims 1 to 7, characterised in that the circumferential face of the mounting bores (9) in the retaining frame (7) and the retaining frame (7) itself consist of stainless steel.
9. Machine according to one of Claims 1 to 8, characterised in that the mounting bushings (10) consist of polypropylene (PP) and/or polyoxymethylene (POM) and/or of a metal sleeve with a silicon carbide ceramic coating.
10. Machine according to one of Claims 5 to 9, characterised in that the fixing sleeves (16) consist of stainless steel.

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