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 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. Brief description of the invention

The present inventive concept substantially lies in obtaining a knife-holder rotor in which one or more knives, but preferably all the knives of the knife-holder rotor, are connected in an elastically yieldable manner, to the support or main body of the knife-holder rotor.

Preferably, the knives are removably mounted on the knife-holder rotor, so as to be able to replace them individually.

Preferably, the position of the knives is radial with respect to the geometric axis of the meat supply and processing channel (which coincides with the rotation axis of the knife-holder rotor and the meat supply auger). In this manner, the knives can "follow" the deformation of the corresponding fixed perforated disc, i.e. be better adapted to this deformation (reducing the friction to a minimum); indeed, the deformation is normally a more accentuated convexity in the central portion of the fixed perforated disc with respect to the peripheral parts thereof.

Preferably, the rotor comprises a central hub surrounded by radial arms integral in rotation with the hub itself; the respective knives are connected - preferably in a removable and elastically yieldable manner - to the ends of the arms opposite the hub, such knives preferably arranged radial and parallel to the radial arms themselves.

Preferably, each knife is inserted through a mounting appendage thereof (opposite the cutting edge of the knife) into the respective free end (opposite the hub of the rotor) of the relative arm - preferably radial - of the rotor.

Preferably, the mounting appendage or the connection appendage, opposite the cutting edge of the knife, which connects the knife (respectively in a removable or non-removable manner) to the arm (preferably radial) of the rotor, bears a weakening incision of the material (normally steel) that constitutes said mounting or connection appendage. The incision made in the steel creates a weakening zone due to which one obtains the desired elastic pliability of the knife of the rotor. In any case, any other system for obtaining this elastic pliability of the knife mounted on the support of the rotor falls within the scope of the same inventive concept, given that the elastic pliability of the knife does not constitute an element that is known in the prior art.

Hence, one could for example use a connection appendage formed by a corrugated sheet, or use another elastic system (helical springs, spiral springs, etc. suitably protected in a casing, or an elastomeric material suitably protected in a steel box, or other).

Each cutting unit bearing at least one knife-holder rotor and at least one perforated disc can comprise at least one innovative rotor according to the present invention, comprising one or more improved knives, i.e. mounted in an elastically yieldable manner on the main body of the rotor. Hence, the present innovative concept is applicable to one or even to parallel units of these processing units present in the supply and processing channel of a machine for producing sausages, preferably mortadella.

In addition, for the obtainment of the knife-holder rotor (or a processing unit) that is the object of the present invention, the materials and technologies already known in the field could also be used, as long as they are compatible (obviously) with the produced innovation. In particular, it is not excluded that a processing unit according to the present invention may also comprise, for example, a knife-holder rotor of conventional type (with fixed or rigid knives) in addition to (of course) at least one innovative rotor. One such combination could be useful for more easily adapting the present invention to the pre-existing machines, or for other reasons.

Brief description of the drawings

The present invention will now be illustrated in more detail, also with reference to the single figure (Figure 1) enclosed with the present patent application, only for the purpose of clarifying the inventive concept of the invention for the man skilled in the art. Figure 1 and the following detailed description exclusively regard a preferred embodiment of the invention, which is only exemplifying and absolutely non-limiting and non-binding. Figure 1 and the relative brief description (hereinbelow) thus serve only for allowing the man skilled in the art to better understand the inventive concept and hence be able to actuate the invention, but not for the purposes of protection of the finding. Indeed, an average man skilled in the art could easily modify this preferred embodiment, and easily obtain equivalent technical results.

Therefore, it is confirmed that the preferred embodiment of the invention, shown in Fig. 1, is the embodiment currently preferred by the inventor and that it can b e easi ly modified/improved in the future while always remaining within the scope of the same inventive concept.

Fig. 1 shows:

a very schematic plan view of a preferred embodiment of a knife-holder rotor according to the present invention, mounted close to (adjacent to) the respective fixed perforated disc, in turn fixed to the cutting unit holder in the swine meat supply and processing channel.

Description of the currently preferred embodiment

In the plan view of Fig. 1 the cutting unit holder 1 is observed for mounting, in an interchangeable manner, a fixed perforated disc 3 - for example through bolts screwable in the holes 2 - within a supply channel.

One such machine for processing meat is for example installed in a very large closed room with controlled temperature (e.g. 16°C), in which the entire production line is installed. The latter comprises a loading hopper which receives a continuous flow of large pieces of cooled meat. The very cold temperature of the meat is also useful for avoiding local overheating, which tends to damage the meat. The pressures in the supply channel are in fact very high. The channel placed downstream of the hopper for loading the meat comprises one or more processing units, each comprising at least one fixed perforated disc 3. The diameters of the holes 4 of the various fixed discs 3 progressively decrease along the channel of the cutting unit. The rotors, like the innovative one shown in Figure 1 and indicated overall with the reference number 5, have various knives that cut the meat before the latter passes into the corresponding perforated disc 3, extruding the meat through the various holes 4. For the sake of simplicity, in Figure 1 (which is very schematic) only some holes 4 of the respective fixed perforated disc 3 of a knife-holder rotor 5 are shown and indicated. The holes 4 are actually more numerous, completely filling the surface of said fixed perforated disc 3.

The knife-holder rotor 5 has a central hub 6 traversed by the rotary actuation shaft (not shown), which is insertable in the non-circular hole 10. From the central hub 6, whose geometric center coincides with the center (axis) of the knife-holder rotor 5 and with the geometric axis of the channel of the cutting unit, various radial arms 7 are extended, integral with the central hub 6 itself. The ends 7' of such radial arms 7 opposite the central hub 6 are connected to the radial knives 8 through a connection appendage, or mounting appendage, 9. The latter is preferably integral with the corresponding knife 8, substantially forming its base that can be inserted and bolted in a respective recess (not shown) obtained in the end T of the radial arm 7. Once the bolts are fixed, the arm 7 is rigidly connected to the relative knife 8. Nevertheless, even if it is preferable to use interchangeable knives 8, nothing prevents the use of knives 8 that form a single body with the respective arm 7. In this case, the connection appendage 9 would be directly connected in a permanent manner to the arm 7.

The appendage 9 has an incision in its material, schematized by the dashed line 9', which confers it a certain elastic pliability. This incision 9' also allows (if desired) mounting the knives 8 with a certain elastic preload against the corresponding fixed perforated disc 3. Such elastic pliability allows a certain oscillation of the knives 8 and even the deformation of the respective fixed disc 3. Indeed, if (as in the prior art) the knives 8 are not adapted to the deformation of the fixed perforated disc 3, there would be the risk of strong wear or even seizure of the elements in contact with each other. It is possible to control and maintain a desired preload, preventing the wear of the knives and discs, by suitably adjusting said preload of the knives through a system of adjustment screws which adjusts, for example, the tilt of the mounting appendage 9, and/or which comprises calibratable preload springs (not shown).

The elastic pliability could be obtained in different ways, for example through a corrugated sheet arranged between the knife 8 and the arm 7, or by inserting a block with helical springs or elastomer elements, all protected within the block arranged between the relative knife 8 and the end 7' of the corresponding radial arm 7.

In the figure, the knives 8 are preferably arranged in a perfectly radial direction; nevertheless they can also (in an alternative embodiment that is not shown) not be perfectly parallel to the radial arms. (In reality, the "radial" arms 7 are slightly offset in the drawing with respect to the radial knives 8, whose axis instead truly passes through the geometric center of the rotor 5, in this embodiment).

Other modifications can be attained without departing from the protective scope of the present invention.

The machine that is the object of the present invention can comprise one or more rotors according to the present invention, in one or more meat processing units. Each rotor of the present invention can comprise at least one knife mounted in an elastically yieldable manner (preferably all the knives will be mounted in an elastically yieldable manner, as in the preferred embodiment of Fig. 1).

The present invention is not limited to the preferred embodiment, described with reference to the single enclosed, illustrated figure.