Technical Field The invention relates specifically but not exclusively to the field of cutting boned fresh meat and cooked meats such as roasts, cooked ham, pates, sausages and so on, into thin slices.

Background Art The prior art teaches various systems for slicing meats so that each slice is of equal width and weight.

Patent publication WO/0065922 teaches an automatic machine for cutting raw meat into slices of a predetermined weight, which comprises a housing of a piece of meat, means for cutting and slicing the piece of meat, means for infeeding between the meat and the means for cutting, means for compressing the piece of meat internally of the housing and for causing the meat to have and maintain during the cutting operation a parallelepiped shape, and means for distancing the slices of meat obtained from the cutting operation.

Italian patent no. RE2000A000072 teaches an automatic machine for cutting meat products into slices of equal weight which comprises a plurality of blades, a housing for a piece of meat, a pushing organ operating on the piece of meat to push it towards the blades so that the meat is cut into slices of equal weight, and a mobile wall which in the closed position defines a wall of the housing; the piece of meat is cut into slices as it passes through the mobile wall in the open

position during the cutting stage; detachment of the meat by the blades is favoured by the closure of the mobile wall.

In US patent US 4,356, 205, a predetermined volume of a frontal part of a piece of meat is positioned against a plate-shaped stop and constrained laterally in a first vice which has a predetermined length, and a straight transversal section of a certain shape, while another part of the piece of meat is laterally constrained in a second vice having a transversal section of the same shape as the first vice.

The piece of meat is cut in a section comprised between the first and second vices.

Patent publication EP-A-0305012 teaches a device for slicing a piece of meat into slices of equal weights, in which the piece of meat is first transversally pressed by a press of a mould, and is then pressed axially by a piston into the cavity of the mould, which mould has a constant transversal section, against a stop surface located at an end of the cavity. The piece of compressed meat is cut into slices during a stepped axial advancement. The cut slices are expelled at one of the pressing cavities.

W099/08843 describes an apparatus having a loading and pre-pressing unit for a piece of meat, a calibrating unit which determines the width and volume of a single slice of meat, a cutting unit for slicing the piece of meat operating between the pre-pressing unit and the calibration unit which is mobile and distances the cut slices of meat one by one.

WO00/67965 teaches a similar device to the above, in which the unit of calibration comprises a plate which is mobile with respect to the loading unit and which exhibits two openings for pressing the meat and for determining the width and volume of a slice.

The latter three above-described solutions all axially compress the piece of meat in a pressing cavity having a constant transversal section of a predetermined

shape; the three solutions also cut the slices transversally one by one while the piece of meat, at each slicing operation, advances axially by a predetermined amount. These known solutions, in particular the latter three, all exhibit considerable limits and drawbacks.

Firstly, they are not precise, i. e. the difference in weights between one slice and another are considerable.

Secondly, the expulsion system for the cut slices from the mould is considerably complicated and not entirely reliable.

Thirdly, the number of slices cut per unit of time is relatively low.

A further drawback is that the cutting zone is rapidly clogged up by blood, membra, films and other residues coming from the piece of meat being sliced, requiring frequent cleaning of the area to maintain the cutting device at an acceptable level of efficiency.

The main aim of the present invention is to provide a process for cutting pieces of meat into slices of equal weight, which process overcomes the drawbacks existing in the prior art.

A further aim is to make available a device which is constructively simple and economical for carrying out the above-described process.

An advantage of the invention is that it enables cutting slices of a same weight with considerable precision.

A further advantage is the productivity of the process.

A further advantage is that the cleaning system of the device is simplified, as is the system for distancing the device from the cut slices.

These aims and advantages and others besides are all attained by the present invention, as it is characterised in the appended claims.

Disclosure of Invention Further characteristics and advantages of the present invention will better emerge

from the detailed description that follows of two preferred but non-exclusive embodiments of the invention, illustrated purely by way of non-limiting examples in the accompanying figures of the drawings, in which: figure 1 is a longitudinal section of a first embodiment of the device according of the object of the invention; figure 2 is a perspective view of a second embodiment of the device of the invention; figure 3 is a transversal section of the device of figure 2 according to two radial section planes of the slicing station 9 and the loading station 10; figure 4 is a transversal section of the device of figure 2 according to two radial section planes of the slicing station 9 and the loading station 10; figure 5 shows a frontal view of the device of figure 2.

With reference to the figures of the drawings, 1 denotes a device for cutting pieces of meat into slices of equal weight.

The device 1 comprises an elongate tubular container 2 having a longitudinal axis x-x which is open at both ends. The container 2 is preferably cylindrical. In the embodiment the container 2 is a single hollow block made from a single piece, but it would be possible to make the container 2 in more than one piece.

The container 2 internally exhibits an axial cavity destined to house one or more pieces of meat M to be cut into slices. The meat can be introduced into the container 2 through one of the openings at the end. The container 2 can be provided with a lateral door (not illustrated) so that the inside of the container 2 can be accessed from the side.

Two opposite walls 3 are mobile coaxially inside the container 2. Each wall, which is in fact a pressor, is preferably slidable axially inside the container 2 (with possibility of control to keep the distance between the two walls constant) and each wall is also supplied with means to peripherally seal on the internal

lateral surface of the container 2. In the illustrated embodiment each wall 3 is part of a piston 3 of an axial hydraulic actuator 4 which is coaxial to the tubular container 2.

A pressing chamber is defined between the mobile walls 3 and the lateral wall of the container 2. The pressing chamber receives and presses the piece of meat M. The pressing chamber, which in the illustrated embodiment is cylindrical, has a variable and controlled configuration and positioning. Preferably the pressing chamber has a straight uniform transversal section over its entire active axial length. It is also preferably for the perimeter of the straight transversal section of the pressing chamber to be curved and free of live edges.

The volume of the pressing chamber is defined by the reciprocal position of the two mobile walls 3. The two mobile walls 3, the movements of which are controlled by the respective axial actuators 4, define the axial position of the pressing chamber and also have the function of compressing, with a predetermined and controlled degree of compression, the piece of meat M placed in the pressing chamber and comprised between the walls. Preferably the piece of meat M is maintained in a compressed state for the whole slicing stage.

The device 1 comprises means for cutting the piece of meat M into slices in a cutting plane which crosses the pressing chamber in a section comprised between the two mobile walls 3.

The means for cutting comprise a rotary blade 5, relatively slim, with a rotation direction H and an axis of rotation y-y which is preferably parallel to the axis of the pressing chamber. The rotary blade 5 identifies a cutting plane which is perpendicular to the axis x-x of the pressing chamber and to the axis direction F of displacement of the opposite mobile walls 3 constituting the ends of the chamber. The rotary blade 5 is peripherally provided with a curved cutting edge which, preferably, is spiral-shaped or shaped in such a way that the radial

distance thereof from the rotation axis y-y is gradually variable according to the angular position (the blade 5 of figure 1 is the same as the rotary blade illustrated in figure 5, also denoted by the number 5).

The means for cutting comprises a guide 6 predisposed to contain a peripheral part of the rotary blade 5 within the cutting plane. At least a part of the guide 6 can be housed, or afforded, in the tubular container 2, i. e. in the wall laterally defining the pressing chamber.

During operation, a piece of meat M is inserted in the tubular container 2 and pressed at a predetermined pressure between the two end walls 3, so as to fill the pressing chamber completely. The piece of meat M, crushed by the walls 3, is translated in direction F by effect of simultaneous coordinated axial displacements, which keep it in the crushed state. Translation is done in such a way that the whole piece of meat M, from one axial end to the other, passes through the cutting plane where the rotary blade 5 is operating. For each complete rotation of the blade 5, during which a slice of meat is cut, there is also an axial advancement by one step of the whole piece of meat, so that the meat is positioned for the cutting of the following slice. The advancement of the piece of meat is preferably done during the exit stage of the rotary blade 5 from the piece of meat.

The meat is sliced as it advances, always in the pressing chamber which is in effect an axially mobile chamber which is kept preferably at a constant volume (the volume of the pressing chamber is effectively the volume of the whole piece of meat which, when crushed, completely fills the chamber). The part of meat which has already been sliced is contained and compressed in the pressing chamber up until the whole piece of meat has been sliced. Once slicing is finished, the meat, now in slices, is extracted from the tubular container 2.

The hydraulic actuators 4 or other movement means of known type, are suitable

for displacing the walls 3 axially and in coordination in order to keep constant or nearly so the reciprocal axial distance thereof. Preferably the movement means also control, for each wall 3, axial step movements with a redefined axial advancement which will be set according to the desired width of the slices to be cut. It would also be possible to have not a step movement but a continuous one if the latter did not negatively influence the efficiency of the cutting action or the conformation of the slices cut.

The axial actuators 4 are both connected to and activated by a same control unit 7 thanks to which is it possible to move the walls 3 axially and simultaneously so that the meat M comprised between the walls 3 and undergoing slicing is kept at the desired degree of compression at each cutting action, after the controlled advancement thereof by an amount which is equal to the thickness of the desired slice.

In figures from 2 to 5 a second embodiment is illustrated, which comprises a device having the same elements as the first embodiment as described and illustrated in figure 1, in which the tubular container 2 which contains the piece of meat to be cut is made in two parts 21 and 22, one of which, denoted by 21, is mobile and interchangeable. The same or similar elements are numbered using the same indications as for figure 1. The control unit 7 and the peripheral guide 6 are present, but not indicated.

The device comprises a slicing station 9, where the means for cutting operate (the rotary blade 5) and the two opposing mobile walls 3, and two transfer stations for the piece of meat M, the first of which is a loading station 10, where the meat to be sliced is introduced into the device, and the second of which is an unloading station 11, where the piece of meat when sliced is expelled from the device.

A rotary carousel 8 with axis z-z and bearing three parallel tubular bodies 21

distanced angularly at 120° from one another, cyclically assumes three positions, in each of which each tubular body 21 is selectively located at the slicing station 9 or the loading station 10 or the unloading station 11. Each tubular body 21 is open at opposite ends thereof.

The slicing station 9 is provided with a fixed tubular body 22 which is coaxial to whichever of the tubular bodies 21 which is positioned in the slicing station 9. The two tubular bodies 21 and 22, one the prolongation of the other, work together to form the tubular container 2 inside which the pressing chamber is defined, crossed by the cutting plane identified by the rotary blade 5.

The loading station 10 comprises a fixed container 12 which is coaxial with whichever of the tubular bodies 21 is located in the loading station 10. The container 12 has an opening through which the piece of meat to be sliced is introduced. A pusher element 13 comprising an axial hydraulic actuator, has the function of transferring the piece of meat from the container 12 to the tubular body 21. The transfer is preferably realised by means of a translation according to the common axis of the container 12 and the tubular body 21.

The unloading station 11 comprises a pusher element 14 predisposed to operate axially to the axis of the tubular body 21 arranged in the unloading station 11.

The pusher element 14 has the function of transferring the sliced piece of meat from the tubular body 21 to a conveyor 21 and removing it in an expulsion direction G.

During operation, the piece of meat is introduced into the container 12, from which it is pushed axially into the tubular body 21, after which the tubular body 21 is transferred, by effect of a suitable rotation of the carousel 8, into the slicing station 9. There the piece of meat is sliced in the way described herein above in reference to the first embodiment of the invention. In this case the mobile pressing chamber, in its axial displacement, involves both the mobile tubular body 21 and the fixed tubular body 22. Once the slicing operation is completed, the piece of meat is replaced in the mobile tubular body 21 by the axial actuators 4. Then the carousel 8 rotates once more to transfer the sliced piece of meat into the unloading station 11 where it is expelled from the carousel and distanced from the device, for example by means of the conveyor 15.