GB2075335A

GB2075335A - Mincing machine

Info

Publication number: GB2075335A
Application number: GB8016255A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-04-01
Filing date: 1980-05-16
Publication date: 1981-11-18
Also published as: DE3012595A1; JPS56139143A; NL8002586A; FR2479023A1; LU82482A1; BE883496A

Abstract

A mincing machine comprises a rotary cutter dish, a drive shaft fixedly mounted on the machine and extending transversely of the cutter dish, and a knife head mounted on the drive shaft and having cutter knives (8, 9, 10, 11) mounted in holders provided at the knife head. The knife holders comprise drive discs (7) which have guides in which the shanks (17) of the knives are received. To retain the knives in position, retaining pins are taken through guide grooves in the bases of the guides, and radial adjustment of the knives is carried out by external operation of rotary spindles which are axially fixed in the drive discs and which are connected to the retaining pins. <IMAGE>

Description

SPECIFICATION Mincing machine This invention relates to a mincing machine, having a rotary cutter dish, a knife head mounted on a drive shaft which has a fixed mounting on the machine and which extends transversely of the cutter dish, knife holders provided at said knife head, and cutter knives mounted in said holders.

The cutter units of the cutter head of a mincing machine of this type, known by way of example from German specification No. 2522 859 comprise a discform knife holder, two knife carriers and two cutter knives.The cutter knives of the knife pair associated with a knife unit are disposed in a recess form in the knife carrier and retained by pins which are secured to the knife carrier. The knife carriers are guided in a dovetail guideway of the knife holder to be radially displaceable to the drive shaft of the knive head and are infinitely adjustable by means of a spindle. In order that the knives, on assembly, may not slip-off from the retaining pins disposed in the knife carriers, and may also be retained fast during adjustment for the purpose of dynamic balancing, each cutter knife is additionally screwed to the cutter carrier.

Transmission of the drive force from the drive shaft of the cutter to the knives via the knife holders and the knife carriers affords the advantage that the faces subjected to stressing during torque transmission, between the drive shaft and the knife holders or the knive carriers and the cutter knives, can be kept respectively large, so that in the case of such knife heads relative to the prior knife heads, in the case of which the cutter knives, via merely narrow opposite zones of the edges of a slot, are in direct positive drive connection with the drive shaft which normally is designed as a polygonal shaft, substantially higher drive powers can be employed.

Disadvantageous in the case of the knife head having the radially adjustable knives according to German specification No. 2522859 is the relatively costly constructional design of the knife receiving means having two knive carriers and a disc-form knife holder for the knife pair of each knife unit.

The requirements in respect of cutters with regard to the quantity and type of material to be processed are at the present day extremely high, so that large cutter bowls (dishes), large cutter lengths and thicknesses and also high speeds of knife heads are necessary. High-capacity cutters travel with drive shaft speeds up to 6000 r.p.m., in the case of a knife length of 120 mm. From this it is apparent that the cutter knives are subjected to a large centrifugal force, so that there is a risk that the generally greasy fixing faces of the knife shanks of the cutter knives, which are secured only due to frictional connection by means of an axial securing, migrate radially outwardly towards the cutter dish wall.This must definitely be prevented, in order to prevent a knife coming into contact with the dish wall and the wall of the hood engaging over the knife head in the working zone, since thereby not only may there occur damage of the cutter dish but also rupture of one or even more cutter knives which are bent-out of the knife plane by the rotating dish. This results in failure of the cutters for the duration of the costly repair of the dish and of the knife head.On the other hand, in the event of impact-like stressing of the knives, for example in the event of impact on bones or on deeply frozen meat contained in the dish, there occurs also migration of the cutter knives secured merely non-positively on the drive shaft, radially inwardly, the result of this being that a portion of the cross-section of the cutter dish is no longer engaged by the knives, so that meat deposited on the wall of the dish is not comminuted to the desired extent.

Thereby, under some circumstances, the entire processed meat mass is impaired in quality, because bone, gristle or rind substance remain in large pieces.

The receiving, securing and infinitely radial adjustability of the cutter knives in the knife holders known from German Specification No. 2522859 affords a maximum degree of safety against undesired radial offsetting of the cutter knives outwardly or inwardly during operation of the meat cutter.

The cutter knives employed in mincing machines having a plurality of cutting sections (cutting edge sections), such as are described for example in French Specification No.1 018 118, havethedisad- vantages that during meat comminution air is sucked in and brings about an undesirable, grayish colouration of the meat, that the meat is torn apart instead of being finely cut, and that the mixing process of the comminuted meat takes place relatively slowly.

The present invention has been developed primarily, though not exclusively, with a view to simplify the knife reception of the cutter knives in the knife holders without impairing the safety of the knives against radial offsetting relative to the drive shaft and improving the cutting effect of the knife heads by a novel design of the cutter knives.

According to the invention there is provided a mincing machine comprising a rotary cutter dish, a knife head mounted on a drive shaft which has a fixed mounting on the machine and which extends transversely of the cutter dish, knife holders provided at said knife head, and cutter knives mounted in said holders, in which:: each knife holder comprises a drive disc having a guide on one side thereof for receiving the shank of a corresponding knife and extending outwardly of the drive shaft; each knife is adjustably mounted in a corresponding guide for movement relative to the drive shaft; and adjustment means is provided which is connected to each knife for adjusting the position of the knife along its guide, said adjustment means comprising a retaining element which is displaceable in a guide groove provided in the guide and an externally operable adjustment spindle mounted in the corresponding drive disc and connected to the retaining element for controlling the position of the latter along its guide groove in order to adjustthe position of the knife rslative to the drive shaft.

In the case of a first embodiment of the drive discs of the knife head, the guides are designed as double guideways extending over the disc diameter on both disc sides, for receiving in each particular instance two cutter knives disposed diametrically opposite each other, the guides being offset through 90" relative to each other.

In the case of a second embodiment of the drive disc, there is provided only one guide for two knives on a disc side.

In a third embodiment of the drive discs for the knife head the guides are designed as simple or single guideways for receiving a cutter knife and are arranged offset through 1800 in an axial plane on both sides of the drive discs.

Expediently, the retaining elements (pins) of the cutter knives are adjustable in the middle longitudinal plane of the guides.

For securing the cutter knives of the knife head against radial offsetting, the knife head is, in advantageous further development of the invention equipped with an adjustable locking of the cutter knives at the drive disc, which is designed as a releasable screw locking means having a securing screw inserted in the cutter knife and which is screwed into a captive sliding member displaceable in a guiding groove arranged in the guiding face of the guide parallel to the guiding grooves of the retaining pins of the cutter knives.

Expediently, the guiding grooves for the sliding members for the screw locking of the cutter knives are arranged diametrically opposite each other in the marginal zone of the guide on the drive disc.

Advantageously, the drive discs are manufactured from a light metal alloy.

Preferably, the cutter knives (designed as pull-in knives and recutting knives) have three cutting sections, namely cutting edges parallel to the lateral faces of the knife, the with reference to the drive shaft outer cutting section of the pull-in knives and of the recutting knives extending convex in crescent form, adopting an acute cutting angle relative to the cutter dish wall and having in the delivery direction of the cutting material a unilaterally obliquely cut cutting flank, the following thereon straight central cutting section of the pull-in knives possessing cutting flanks unilaterally obliquely cut in the delivery direction and the straight, central cutting section of the recutting knives possessing cutting flanks obliquely cut on both sides, and the with reference to the drive shaft inner cutting section of the pull-in knives and of the recutting knives also extending rectilinearly and at an angle to the central cutting section, and being provided with a cutting flank which is unilaterally obliquely cut in the delivery direction.

Finally, a preferred feature is to be seen to reside also in a novel design of the knife head cutting sets for preparation of various types of sausage having varying qualities.

The knife head cutting sets may comprise individual knife units which are arranged offset relative to each other on a drive shaft.

A knife head cutting set for the preparation of hard sausage from frozen meat at a temperature of down to -200C has three knife units spaced by spacer discs and which are in each particular instance arranged on the drive shaft through 60 in the anti-clockwise direction (sic) the in the delivery direction of the material to be cut first knife unit comprising a drive disc having two pull-in knives arranged offset to 80" on both sides, and the second and third knife unit comprising in each particular instance a drive disc having two unilaterally and diametrically opposite each other arranged recutting knives.

A knife head cutting set for the preparation of various sausage types from frozen meat has three knife units spaced by spacer discs and which are in each particular instance arranged offset through 60 in the anti-clockwise direction on the drive shaft, the in the delivery direction of the material be cut first knife unit comprising a drive disc having two pull-in knives arranged offset through 1800 on both sides, the second knife unit comprising a drive disc having two unilaterally diametrically opposite arranged recutting knives, and the third knife unit comprising a drive disc having two recutting knife pairs arranged offset on both sides and through 90" and the knives of which are disposed in each particular instance diametrically opposite each other on the drive disc.

Finally, a knife head cutting setforthe meat cutter according to the invention, for the preparation of boiled sausage and Bruhwurst has two knife units separated by a spacer disc and which are arranged offset through 30 in the anti-clockwise direction on the drive shaft, the in the delivery direction of the material to be cut first knife unit comprising a drive disc having a pull-in knife pair and a recutting knife pair, arranged offset on both sides and through 90" at the drive disc, and the second knife unit having a drive disc having two recutting knife pairs arranged offset on both sides and through 90 , the knives of each knife pair being disposed diametrically opposite each other on the drive disc.

The knife head of the meat cutter according to the invention satisfies requirements made to a maximum degree with regard to high power cutters;rela- tive to the quantity of meat to be processed, the quality of the meat goods produced, and also operational safety.

A further advantage is to be seen to reside in the fact that with the novel drivedisc it is possible to assemble knife heads with varying cutter sets, which has a number of knife units determined by the sorts of meat to be processed and the meat goods to be manufactured, and which comprise a drive disc fitted with two or four cutter knives. Due to the employment of drive discs having four cutter knifes, relative to a cutter head having an equal number of knives, the number of drive discs can be diminished, so that storage and therewith operating costs are reduced. Finally, the equipment of the cutter heads with drive discs fitted with four knives affords a substantially improved cutting effect and therewith an improved cutter capacity.

To the decisive increase in the cutter capacity there contributes furthermore the novel design of the cutter knives. Due to the design of the cutting edges of the recutting knives, having a crescent-form convex outer cutting section which has a cutting flank unilaterally obliquely cut in the delivery direc tion of the meat material, a straight central cutting section following thereon and having cutting flanks obliquely cut on both sides, and an inner straight cutting section having a cutting flank which is also unilaterally obliquely cut in the delivery direction, there is achieved a cutting effect which is substan tially improved relative to the known cutting knives.

This improvement of the cutting effect is based on the following mode of operation of the cutter: The straight central and the straigh inner cutting section produce a coarse cut of the larger meat pieces which are comminuted and, due to the rota tion of the knife, centrifugally hurled outwardly at the cutter dish wall in the zone of the crescent shaped outer cutting section, with the maximum peripheral velocity of the knife, due to which the comminuted meat pieces are finely cut with a "draw ing" cut, whereby the "drawing;' cut is made poss ible by the acute cutting angle between the crescent-shaped cutting section and the cutter dish wall.Due to the double-side cutting of the central cutting section, which exerts a predetermined wedge-effect on the roast materials, a damming-up effect is achieved due to which the delivery of the roast material is delayed by the cutting set equipped with the novel cutting knife and the roast material is supplied for repeated cutting to the outer cutting section of the as seen in the delivery direction pre arranged knife, and in the zone of the central cutting section is intensively mixed, whereby good bonding of the meat to be processed is achieved.

Due to the cutting on both sides of the central cut ting section, the knife is uniformly subjected to fric tional action at this most vigorously stressed loca tion, and therewith stabilised.

The increased cutting effect results in substantial shortening of the processing time for the meat and therewith in a reduction of the operation and man ufacturing costs.

Embodiments of mincing machine according to The invention will now be described in detail, by way of example only, with reference to the accompany ing drawings in which: Figure 1 is a perspective view of a mincing machine according to the invention; Figure 2 is a plan view of a drive disc for the knife head of the mincing machine which is equipped with a group of four cutter knives; Figure 3 is a view, similar to Figure 2, but with the cutter knives removed; Figure 4 is a side view of the drive disc shown in Figure 3; Figure 5 is a partial section taken along the line V-V in Figure 2; Figure 6 is a plan view of a further embodiment of drive disc; Figures 7 to 9 are cross-sections of three cutting edge portions of a recutting knife taken along the section lines VII-VII, VIII-VIII and IX-IX respectively in Figure 2;; Figure 10 is a cross-section through the central cutting portion of a pull-in knife; and Figures 11 and 12,13and 14,and 15and 16are side views and plan views ofthree cutter knife sets for a mincing machine according to the invention, for the preparation cf various types of sausage.

In the case of the individual embodiments, like or similar components are characterised by identical reference numerals.

The main constructional elements of the mincing machine according to Figure 1 are the cutter dish 1 closable by a lid 2 for receiving the meat 3 to be processed, the said dish being driven in rotation about a vertical pivot in the direction of arrow a, and also a knife head 4 rotating within the cutter dish 1 in the direction of the arrowb and which is disposed on a fixedly mounted drive shaft 5 which extends along a chord thereof of the dish 1.

A knife unit 6 according to Figure 2, for assembly of the knife head 4, comprises a drive disc 7 fitted for example with four cutter knives 8,9, 10, 11. The knives 8, 10 are disposed diametrically opposite each other in a guide 12 on one side 13, and the knives 9, 11 are arranged in a guide 14 offset through 90 on the other side 15 of the drive disc 7, as shown in Figures 3 and 4.The guides 12, 14 comprise wide flat grooves extending generally diametrically on the sides 13, 15 of the disc 7, the bases of the grooves forming an abutment and guiding face 16forthe front or rear side of the shanks 17 of the knives 8,9, 10, 11. Each knife shank 17 is fitted as a slide fit into the guide 12 or 14 and is guided with its straight narrow sides 18, 19 along the groove edges 20,21 of the respective guide. The drive disc 7 has a central hexagon bore 22 through which is taken a hexagonal drive shaft 5. The cutter knives 8,9, 10, 11 are infinitely adjustable in each particular instance in the guides 12, 14 by retaining elements in the form of retaining pins 23, radially of the drive shaft 5.To this end, each retaining pin 23 is displaceable in a respective guiding groove 24 formed in the guiding face 16 of the guides 12 or 14, by an adjusting spindle 25 which extends in the central longitudinal plane 2626 of the guides 12, 14. The adjusting spindles 25 for the cutter knives 8, 9, 10, 11 are axially fixed in the drive disc 7 and are mounted for rotation and for adjustment from the exterior.

In order that the cutter knives 8, 9, 10, 11 (on assembly of a cutter head) may not slip off the retaining pins 23, they are also secured to the drive disc 7 during radial adjustment for the purpose of dynamic balancing by the provision for each knife of an adjustable screw locking means 27. The screw locking means 27 comprises a hexagonal screw 28 inserted into each cutter knife (8, 9, 10, 11) and which is screwed into a captive sliding member 29 displaceable in a guiding groove 30 arranged in the guiding face 16 ofthe guide 12 or 14 parallel to the guiding grooves 24 of the retaining pins 23. Each of the two guiding grooves 30 for the slide members 29 of the screw locking means 27 associated with each pair of cutter knives are arranged diametrically opposite each other in the marginal zone of the guides 12 and 14, on the two sides 13, 15 ofthe drive disc7.

The screw-locking means is employed for a minc ing machine of a size in excess of a predetermined minimum e.g. having a volume of 200 litres. In the case of volumes (of the cutter dish) below 150 litres, instead of the screw locking means preferably retaining magnets are employed, and these are inserted into the drive discs.

While there is shown in Figure 4 guides (12 and 14) on each side of the drive disc 7 to receive two pairs of cutter knives, there may be provided a drive disc having a guide on only one side to receive a pair of cutter knives (see 7a in Figure 3).

A further embodiment of a drive disc 31 according to Figure 6 is provided with two guides 32,33 designed as single guideways for receiving in each particular instance only one cutter knifes the guides 32,33 ofthe drive disc 31 are arranged offset through 1800 in an axial plane on both sides ofthe drive disc. The adjustment and locking of the cutter knives in the case of the drive disc 31 according to Figure 6 are the same as in the case of the drive disc 7 according to Figures 3 and 4.

The drive discs 7, 7a and 31 are preferably manufactured from a light metal alloy.

The knife cutting edges of the recutting knife 10 according to Figure 2 is subdivided into three cutting edge sections which are variously cut (or ground).

The outer cutting edge sections 34 extends convexly in crescent-form, adopts an acute cutting angle to the cutter dish wall 35 and has in the delivery direction c of the minced material an oblique cutting edge flank 34a as shown in the cross-section profile according to Figure 7. The central cutting edge section 36 extends straight and has two oblique cutting edge flanks 36a 36b. The inner cutting edge section 37 also extends straight and at an angle to the central cutting edge section 36 and has, like the outer cutting edge section 4 a cutting edge flank 37a which is obliquely cut or ground in the delivery direction c of the minced material.

In the case of the cutting knives designed as pull-in knives 10a for the knife head of the mincing machine, the knife cutting edge is continuously obliquely cut or ground unilaterally in the delivery direction of the minced material, so that the central cutting edge section 36 has, like the outer and the inner cutting edge section 34,37, an oblique cutting edge 36a (Figure 10).

The peripheral velocity of the cutter knife tO is highest in the zone of the outer cutting edge section 34, so that this cutting edge section hasthe maximum cutting effect which is additionally increased by the advantageous cutting edge angle relative to the cutter dish 35. Due to the high peripheral velocity ofthe cutter knife 10 in the outer cutting edge section, there is a tendency for the frictional heat developed there to be at a maximum. This frictional heat is, however, undesirable in the preparation of sausages and particularly in the preparation of very finely minced meat for saveloys.Due to the unilat eral cut of the cutting edge flank 34a, gentle trans port and clean cutting of the meat to be comminuted is achieved, and due to the supplementary convey ing effect of the unilaterally cut or ground gutting edge section 34a of the cutter knife, the frictional heat produced does not have a disadvantageous effect.

In the zone of the central cutting edge section 36 of the cutter knife 10, the peripheral velocity and therewith also the frictional heat is smaller, so that here the meat to be minced can no longer be strns- sed. Due to the central cutting edge section 36, a damming-up effect is achieved and the meat is maintained in this zone of the cutter dish.

The meat is, for further cutting, fed to The outer cutting edge section 34 of the knife prearranged in the conveying direction. Additionally, the meat is, in the central cutting edge section 36, very considerably displaced in- itself and mixed, and this produces uniform granulatian in the preparation of hard sausage (Dauerwurst)..rnthe preparation of boiled sausage and Briihwu rst, this has an extremely advantageous effect on emulsification. Thereby, good bonding of the meat-to be processed is achieved.

Since the cutter knife is cut or ground on both sides in the central cutting edge section 36, it is uniformly subjected to frictional action from both sides at this most strongly stressed location, and therewith stabilised, so that also the risk of rupture is reduced.

The cutter knife achieves a good splitting effect also in the processing of frozen meat.

The inner cutting edge section 37 of the cutter knife 10 serves for drawing-in, splitting and transporting of the meat to be minced. Due to the variously ground or cut cutting edge sections 34,36,37 advantageous revolving of the meat to be processed in the cutter dish 1 is achieved. The cutter knife 10 can be employed for the processing of all types of meat, for the preparation of various types of sausages The individual cutting edge sections 34,36,37 of the cutter knife 10 can be re-ground or re-cut without difficulty and also drawn-off without difficulty in the cutter during maintenance work using a whetstone.

The knife head 38 for a meat cutter according to Figures 11 and 12 is equipped with a cutting set for manufacturing Dauerwurst from frozen meat at a temperature down to -20"C. The cutting set is assembled from three knife units 39,40,41, which are spaced by spacer discs 41 and are arranged on the drive shaft 5, offset in each particular instance through 6(ion in the anti-clockwise direction.

With respect to the conveying direction c of the material be minced, the first knife unit 39 comi prises a dive disc 31 (according to Figure 6) having two pull-in knives43,44which rotate in two cutting edge planes and the axial spacing of which corresponds approximately to the drive disc widths reduced buy the amount of the single knife thickness, and which are offset relative to each other th rough 180 . The cutting edge of the knife 43,44 is, to cor respondtothepull-in knife 10a accordingto Figure 2, ground continuously over all cutting edge sections unilaterally in the conveying direction c. The second and third knife units 40,41 have a drive disc 7a (according to Figure 3), provided with a double guideway for in each particular instance two recutting knives 45,46 and 47,48 arranged diametrically opposite each other and rotating in a cutting edge plane.

The thickness of the shank 17 of the pull-in knives 43,44 and also of the recutting knives 45,46,4748 is somewhat greater than the depth of the guides 12, 32,33 for the knives, and the retaining pins 23 of the knives are somewhat sunk in the receiving bore 49 (see Figure 2) of the knife shank 17. Thus, on secur ing the cutting set of the knife head 38 on the drive shaft 5, against the locking disc 50 by means of the locking nut 51 applied on the free end of the drive shaft 5, the knives are retained, in addition to the non-positive securement on the drive shaft 5 by the retaining pins 23, also due to frictional connection, and are reliably maintained in position up to the maximum centrifugal forces on rotation of the knife head 38 at speeds up to 6000 r.p.m.

The knife head 52 for a mincing machine according to Figures 13 and 14 is equipped with a cutting set for the preparation of various types of sausage from frozen meat. The cutting set is assembled from three knife units 53,54,55 separated by spacer discs 42 and which, in each particular instance, are arranged offset through 60 in the anti-clockwise direction on the drive shaft 5.With respect to the conveying direction c of the material to be minced, the first knife unit 53 comprises a drive disc 31 (according to Figure 6) having two pull-in knives 56, 67 arranged offset on both sides and through 180 , the second knife unit 54 comprises a drive disc 7a (according to Figure 3) having two recutting knives 58, 59 arranged unilaterally and diametrically opposite each other, and the third knife unit 55 comprises a drive disc 7 (according to Figure 3) having two re-cutting knife pairs arranged offset on both sides and through 900 and the knives 60, 61 and 62, 63 of which are disposed in each particular instance diametrically opposite each other on the drive disc 7.

The third knife head 64 according to Figures 15, 16 is fitted with a cutting set for the preparation of boiled sausage and Bruhwurst. The cutting set is assembled from two knife units 65,66 separated by a spacer disc 42 and which are arranged on the drive shaft 5 offset through 30 in the anti-clockwise direc- tion. With respect to the delivery direction c of the material to be minced, the first knife unit 65 comprises a drive disc 7 having a pull-in knife pair 67, 68 bnd a recutting knife pair 69,70, which are arranged on the drive disc 7 offset on both sides through 90 , and the second knife unit 66 has a drive disc 7 having two recutting knife pairs 71,72 and 73,74 arranged offset on both sides and through 900, the knives of each knife pair being disposed diametrically opposite each other on the drive discs 7.

Due to the arrangement of spacer discs between the knife units of the various knife head cutting sets, there is achieved smooth handling of the meat which guarantees complete loading of the cutting capacity of each individual knife unit.

Claims

1. A mincing machine comprising a rotary cutter dish, a knife head mounted on a drive shaft which has a fixed mounting on the machine and which extends transversely of the cutter dish, knife holders provided at said knife head, and cutter knives mounted in said holders, in which: each knife holder comprises a drive disc having a guide on one side thereof for receiving the shank of a corresponding knife and extending outwardly of the drive shaft; each knife is adjustably mounted in a corresponding guide for movement relative to the drive shaft;; and adjustment means is provided which is connected to each knife for adjusting the position of the knife along its guide, said adjustment means comprising a retaining element which is displaceable in a guide groove provided in the guide and an externally operable adjustment spindle mounted in the corresponding drive disc and connected to the retaining element for controlling the position of the latter along its guide groove in order to adjust the position of the knife relative to the drive shaft.

2. A mincing machine according to claim 1, in which said spindle is mounted in the drive disc so as tp be fixed with respect to the axis thereof and is rotatable in order to carry out adjustment of the retaining element.

3. A mincing machine according to claim 1 or 2, in which the guides are each designed as double guideways extending throughout the drive disc diameter and each receiving a pair of cutter knives disposed diametrically opposite each other.

4. A mincing machine according to claim 1 or 2, in which the guides are each designed as single guideways receiving a single cutter knife.

5. A mincing machine according to claim 3, in which the double guideways are offset relative to each other through 900 and are arranged on relatively opposite sides of the drive disc.

6. A mincing machine according to claim 1 or 2, in which the guides for the cutter knives are offset through 1800 in an axial plane on opposite sides of the drive disc.

7. A mincing machine according to any one of the preceding claims, in which the retaining elements comprise retaining pins which are adjustable in the central longitudinal plane of the respective guide.

8. A mincing machine according to any one of the preceding claims, including an adjustable locking means for each cutter knife which comprises releasable screw locking means having a threaded fastener inserted into the knife and which is screwed into a captive slide member which is displaceable in a guide groove in a guide face of the guides, the guide groove extending parallel to guide grooves provided for the retaining elements.

9. A mincing machine according to claim 8, in which the guide grooves for the captive slide members are arranged in the marginal zones of the guides.

10. A mincing machine according to any one of the preceding claims, in which each drive disc is made from a light metal alloy.

11. A mincing machine according to any one of the preceding claims, in which the cutter knives are designed as pull-in knives and recutting knives having three cutting sections provided with cutting edges parallel to the lateral faces of the knife, the outer cutting section (with reference to the drive shaft) of the pull-in knives and of the recutting knives extending in crescent-shape convex manner, adopt ing an acute cutting angle (a) relative to the wall of the cutter dish and having in the delivery direction (c) of the minced material a unilaterally oblique-cut cutting flank, the straight central cutting section following thereon of the pull-in knives possessing cutting flanks unilaterally obliquely cut in the delivery direction and the straight central cutting section of the recutting knives possessing cutting flanks obliquely cut on both sides, and the (with reference to the drive shaft) inner cutting section of the pull-in knives and of the recutting knives also extending straight and at an angle to the central cutting section and being provided with a cutting flank which is unilaterally obliquely cut in the delivery direction.

12. A mincing machine according to any one of the preceding claims, including a knife head cutting set having knife units arranged offset relative to each other on a drive shaft.

13. A mincing machine according to any one of the preceding claims, having a knife head cutting set for the manufacture of hard sausage from frozen meatata temperature down to -20"C, in which the cutting set has three knife units spaced by spacer discs and which are arranged in each particular instance offset through 60 in the anit-clockwise direction on the drive shaft, the knife unit which is first in the delivery direction (c) of the material to be minced comprises a drive disc having two pull-in knives arranged offset on both sides and through 1809 and the second and third knife units comprising in each particular instance a drive disc having two recutting knives arranged unilaterally and diametrically opposite each other.

14. A mincing machine according to any one of claims 1 to 12, having a knive head cutting set for preparing various types of sausage from frozen meat, in which the cutting set has three knife units spaced by spacer discs and which are in each particular instance arranged offset through 60 in the anti-clockwise direction on the drive shaft, the first knife unit (with respect to the delivery direction of the material to be minced) comprising a drive disc having two pull-in knives arranged offset on both sides and through 180q the second knife unit comprising a drive disc having two recutting knives arranged unilaterally and diametrically opposite each other, and the third knife unit comprising a drive disc having two recutting knife pairs arranged offset on both sides and through 90" and the knives of which are disposed in each particular instance diametrically opposite each other on the drive disc.

15. A mincing machine according to any one of claims 1 to 12, having a knife head cutting set for the manufacture of boiled sausage and Bruhwurst, in which the cutting set has two knife units separated by a spacer disc and arranged offset on the drive shaft through 30 in the anti-clockwise direction, the first knive unit (with respect to the delivery direction of the material to be minced) comprising a drive disc having a pull-in knife pair and a recutting knife pair, arranged offset on both sides and through 90" on the drive disc, and the second knife unit having a drive disc provided with two recutting knife pairs arranged offset on both sides and through 90 , the knives of each knife pair being disposed diametrically opposite each other on the drive discs.

16. A mincing machine according to claim 1 and substantially as hereinbefore described with reference to and as shown in any one of the embodiments illustrated in the acc3mpanying drawings.