Description

Field of the art

The present invention refers to the field of production of sausages, in particular of mortadella, and specifically it regards an improvement of the knife-holder rotors of the machines for producing sausages and more particularly mortadella.

Prior art

In the description of the present patent application, reference will generally be made to mortadella; however, this term will more generally refer to the production of sausages, so as to not overly limit the present invention.

Known in the art of mortadella production lines are machines in which considerable quantities of cold meat (very hard) are continuously inserted in a meat passage channel, where this swine meat is pressed against a plurality of perforated discs (with progressively smaller holes) in order to render it soft and uniform. The meat thus processed is then filled, in separate portions (after the addition of additives known in the field, such as aromas etc.), in respective tubular casing elements for each portion, which are then closed.

These machines still today present many problems.

Indeed, for the processing, very high pressures must be applied in the processing channel/duct by the rotary system, which is constituted by the rotation shaft of the knife- holder rotors and by the knife-holder rotors themselves, as well as by the supply auger. The knives press the meat with these very high pressure and cutting forces against the perforated discs, which are fixed, in order to extrude the meat through the holes of the various discs. The diameter of these holes is narrowed between a fixed disc situated more upstream and a fixed disc placed more downstream in the channel. The knives of a rotor must be arranged directly adjacent to the corresponding perforated disc, in order to be able to exert the desired pressure on the meat and push it (in addition to cutting it) against the respective perforated disc, so as to make it exit from the holes of the perforated disc. Different units of this type are normally provided in the channel of the processing machine, i.e. various units comprising stationary perforated discs, as well as knife-holder rotors; for example, a pair of fixed perforated discs arranged in approached position encloses one or two knife-holder rotors arranged between said two fixed perforated discs. Another knife-holder rotor can be arranged more upstream in the channel, always directly adjacent to the perforated disc arranged more upstream. The processing of the meat occurs via successive steps, from one unit to the next, and in each unit the knives slide on the respective perforated disc rotating around the geometric axis of the supply channel. Unfortunately, notwithstanding the very high strength of the perforated discs (made of steel), the peaks of pressure acting on the central part of the perforated discs cause a convexity in this central part, such that the knives tend to generate very high friction forces against a stationary perforated disc that is deformed. The consequences are the following:

a considerable quantity of steel particles generated by such friction between the knives and the respective perforated disc is mixed with the meat and is found in the finished product (since the steel is often an alloy, health-endangering materials can be mixed with the meat);

- the worn components (discs, knives, etc.) must be regularly replaced and/or repaired;

- the greater friction developed between the perforated disc which is bent and the knives (which are in contact therewith) generates considerable heat (e.g. a meat temperature up to 70°), causing the organoleptic characteristics of the swine meat to deteriorate; the effect of the heat is also visible to the naked eye in the finished product (rather dark spots in the mortadella), giving the consumer the impression that he has purchased a product of lower quality.

Hence, the object of the present invention is to remedy the preceding drawbacks of the conventional machines for processing swine meat for producing mortadella. Thi s i s accomplished by proposing, in a machine of the abovementioned type, a rotor of improved type that protects its knives and discs from wear, from seizure and other events, and which also does not release (or considerably limits the release of) dangerous metals into the swine meat that are then found in the finished product.

Brief description of the invention

The invention obtains its objects and advantages as indicated in the enclosed claims.

Substantially, a completely innovative solution is proposed in which the knife-holder rotor, situated in the swine meat supply and processing channel, rather than having knives fixed to the support, has different knife support systems on two opposite sides. Such systems render the knives movable (rather than fixed) with respect to the body of the knife-holder rotor. Preferably, the first of these knife support systems is elastic.

Preferably, the second of these knife support systems is of rotatable type, in which each knife is rotatable around a pin arranged tangentially with respect to the rotation sense of the knife-holder rotor.

Preferably, in the first knife support system, the knives are subjected to an adjustable elastic preload, in the sense that by means of an adjustment screw, or the like, one can adjust the preload with which the blade of the knife presses against the relative fixed perforated disc for the meat extrusion.

Substantially, the inventive concept consists of rendering the knives movable (within certain limits), in a manner so that they can follow the deformations of the respective fixed perforated disc, induced by the very high pressures existing within the supply channel of the machine.

Preferably, the knife-holder rotor is also "floating", in the sense that it is not rigidly fixed to the rotary actuation shaft of the rotor, but rather can slide (within certain limits) along the axis of this rotary shaft.

The present invention can be modified in many different ways by a man skilled in the art, always remaining within the scope of the same inventive concept as this is expressed in the following detailed description and above all as this is defined/specified in the enclosed claims.

Brief description of the drawings

The present invention will now be illustrated in more detail by means of a preferred embodiment thereof given as merely exemplifying, non-limiting and non-binding, and which is represented in Fig. 1 (figure 1), which shows:

Fig. 1, a schematic side view, in cross section, of an innovative processing unit (mountable in the supply and processing channel of a machine for producing sausages/mortadella) comprising a knife-holder rotor obtained according to the criteria of the present invention.

Detailed description of a preferred embodiment of the invention

Fig. 1 shows a ring nut 1 for mounting, in the channel/duct (not represented) for supplying the swine meat, a processing unit of which the ring nut 1 itself is part. Such processing unit, indicated overall with the reference number 2 in Fig. 1, could be termed, in an extensive manner, cutting and extrusion unit or cutting and drawing unit.

The rotation axis of the knife-holder rotor 3 according to the present invention, which is part of the processing unit, is not shown. The meat supply auger (also not represented) can be fixed on the rotation axis. The rotation axis for example also supports, at the base of the supply auger, a conventional knife-holder rotor 4 with fixed radial knives 5 with respect to the same rotor 4.

The processing unit of the invention comprises, in addition to the conventional fixed perforated discs 6, 6' that are extended over the entire cross section of the meat supply duct, and which are fixed to the mounting ring nut 1, also the abovementioned innovative rotor 3, which is arranged as a sandwich between said fixed perforated discs 6, 6' of conventional form.

Hereinbelow, for the sake of clarity the following definitions are used: - the adjective "upper" indicates an element, a surface, etc. arranged "upstream" with reference to the natural flow direction of the swine meat in the channel (arrow F in

Fig. l);

"lower" instead indicates a component, a surface, etc. arranged "downstream" with respect to said direction F in Fig. 1.

As can be seen in Fig. 1, the lower surface 7 of the body 8 of the knife-holder rotor 3 of the invention is spaced from the upper surface 9 of the fixed lower disc 6'. Likewise, the upper surface 10 of the knife-holder rotor 3 is spaced from the lower surface or side 11 of the fixed upper perforated disc 6.

In the conventional machines, the conventional knives 5 (fixed with respect to the rotor 4) of the knife-holder rotor 4 of conventional type are in contact with and slide/rub against the upper surface (or side) 12 of the fixed upper perforated disc 6.

In the present invention, however, the rotatable knives 13 are mounted on the upper part of the knife-holder rotor 3 of innovative type, and they are in contact with and slide/rub against the lower surface 11 of the fixed upper perforated disc 6.

The rotatable knives 15 are spring-loaded, according to the present invention, mounted on the lower part of the knife-holder rotor 3 of innovative type, and they are in sliding/rubbing contact with the upper surface 9 of the fixed lower perforated disc 6'.

In detail, the (upper) rotatable knives 13 are mounted in radial direction within corresponding radial recesses 18 of single radial arms 19 of the innovative knife-holder rotor 3. There could, for example, be four of such radial arms 19, integral with the central hub 8. In this case, there would of course also be four rotatable upper knives 13. Rotation pins 14 tangentially traverse (perpendicular to the single radial arm 19) the respective housing recess 18 of a rotatable knife 13 and rotatably support the knife. Each rotatable knife 13 has a slightly rounded form at its radial ends (respectively internal and external), and by exploiting a minimum clearance that is available within the radial recess 18, it can oscillate and hence follow the deformations developed over time by the fixed upper perforated disc 6 (convexity of the lower surface 11). The lower knives 15 are mounted in an oblique (angled) and oscillating manner around the rotation axis 17 thereof. For each radial arm 19, there is also one such rotatable lower knife 15, which presses against the upper surface 9 of the fixed lower perforated disc 6'. Indeed, each rotatable lower knife 15 is spring-loaded, given that a mechanism 16 is provided with adjustable stop abutment of the tilt angle of the knife, which also exerts an (adjustable) elastic preload on the knife itself, or better yet on the rotation pin 17 side end thereof.

Preferably, given that - in the preferred embodiment described herein - the knife-holder rotor 3 is mounted in a "floating" manner on the rotation shaft (not illustrated), it can not only slide within certain limits along this rotation and actuation shaft, but the elastic preload on the rotatable lower angled knives 15, pressing against the fixed lower perforated disc 6', maintains the rotatable upper knives 13 (bearing the tangential pin 14) under pressure against the lower surface 11 of the fixed upper perforated disc 6.

Overall, the action carried out by the improved rotor 3, according to the present invention, is to press the knives 13, 15 against the perforated discs 6 and 6', thus always maintaining them in contact with such discs but following the deformations thereof over time so as to prevent all the drawbacks attributable to the prior art already illustrated in the introduction of the patent application.

List of reference terms

1 mounting ring nut

2 processing unit

3 knife-holder rotor (of the invention)

4 knife-holder rotor (conventional)

5 knives (of 4)

6 fixed upper perforated disc

6' fixed lower perforated disc

7 lower surface of the rotor 3

8 body of the rotor (or central hub) upper surface (of 6')

upper surface (of the rotor 3)

lower surface (of 6)

upper surface (of 6)

upper knives (of 3)

pin

lower angled/oblique knife (of 3)

adjustable system of elastic preload and abutment rotation axis of 15

housing recess

radial arm