Machine for pressing fruits or similar products, and method for cleaning its drainage channels

Abstract

 An improved machine (2) for pressing fruit or similar products, comprising:
- a cylindrical drum (4) rotating about a central shaft (6),
- a plurality of annular-shaped grids (12) applied to the interior of the drum (4) and spaced therefrom such as to define, with the inner surface (10) thereof, drainage channels (18) each provided with at least one aperture (22) communicating with a manifold (24) connected to the environment external to the machine,
- a membrane (8) wrapped about said central shaft (6) and intended to be selectively inflated in order to press the product against the inner surface (10) of the drum (4) and against said grids (12) such that the liquid obtained by pressing can be collected inside said drainage channels (18),
characterised in that the drainage channels (18) are provided in their interior with a plurality of free bodies (20) intended to be put into movement by the rotation of the machine drum (4), there being provided, to correspond with each aperture (22) of the drainage channels (18), an element (26) which surrounds said aperture (22) and is positioned at a distance (30) from the wall standing in front of the drainage channel (18) which is less than the minimum dimension of said bodies (20).

Description

[0001] The present invention relates to an improved machine for pressing fruit or similar products, and a method for cleaning its drainage channels.

[0002] Machines for pressing fruit, in particular grape, are known from EP 0721836. These machines are normally of pneumatic type and comprise a cylindrical drum rotating about a central shaft provided with four longitudinal radial fins, and a membrane supported by these latter. Annular grids are applied to the interior of the drum shell covering which, together with the shell covering, define annular spaces spaced along the drum axis and defining drainage channels. The interior of these collect the liquid obtained by pressing the product by the membrane, into which compressed air is fed to cause it to adhere to the shell covering and to the grid of the drum. The drainage channels are also provided with apertures which converge into a single manifold connected to the environment external to the machine.

[0003] A machine of this type is also known from EP 1338408. The main drawback of this type of machine is the fact that inevitably not only liquid from the pressed product enters the drainage channels, but also solid residues which deposit on the channel walls to block the through apertures of the grids, with consequent reduction in the drainage area.

[0004] To overcome these drawbacks, the drainage channels have to be periodically cleaned. This is currently achieved by halting the machine, in order to be able to open the drum loading door, then entering the drum with a spray tube which feeds high pressure water onto the apertures of the drainage channel grids. In addition, in certain cases, brushes have to be fed into the drum, or the drum be filled with detergents (for example based on caustic soda), to then rotate the drum for a certain period before draining off the solution of water and detergent. Finally, in other cases, the drainage channel grids have to be removed from their seats inside the drum, in order to wash them carefully.

[0005] All these know methods for cleaning the drainage channels require the machine to be halted, resulting in a loss of time and a consequent lesser machine efficiency and productivity.

[0006] JP H02 125789 describes a machine in which the cylindrical drum rotation causes the movement of a plurality of free bodies contained inside the drainage channel. In particular, when these bodies move, they come into contact with and rub the surfaces defining the drainage channel, to hence prevent deposition of solid residues on the surfaces, while at the same time removing any residues which have managed to adhere to the said surfaces.

[0007] The main object of the invention is to eliminate the drawbacks of traditional machines by proposing an improved machine for pressing fruit or the like which requires no stoppage for cleaning the drainage channels.

[0008] Another object is to propose a method for cleaning the drainage channels which is performed automatically by the machine itself, without any intervention by the operator.

[0009] Another object of the invention is to propose a method and machine in which the cleaning of the drainage channels is effective and complete.

[0010] Another object of the invention is to propose a machine and method which are simple and economical.

[0011] All these objects and others which will be apparent from the ensuing description are attained according to the invention by an improved machine for pressing fruit or the like with the characteristics indicated in claim 1.

[0012] The invention also comprises a method for cleaning the drainage channels in a machine for pressing fruit or the like, with the characteristics indicated in claim 13.

[0013] The present invention is further clarified hereinafter with reference to the accompanying drawings, in which:

Figure 1 is a vertical perspective section through the improved machine for pressing fruit or the like according to the invention,

Figure 2 is a vertical section through the machine of Figure 1,

Figure 3 shows an enlarged detail of Figure 2,

Figure 4 shows a perspective view of a portion of an annular grid present in the machine of Figure 1, and

Figure 5 is an enlarged front view of an element of Figure 4.

[0014] As can be seen from the figures, the machine 2 according to the invention for pressing fruit or similar products, in particular grape, is of the type according to EP 0721836 and comprises a drum 4 rotating about a central shaft 6 provided with four longitudinal radial fins 7 which support a tubular membrane 8 of soft atoxic material.

[0015] A series of annular grids 12 are fixed to the inner surface 10 of the shell covering of the drum 4. In particular, the space between the inner surface 10 of the shell covering of the drum 4 and the outer surface 16 of each grid 12 forms a drainage channel 18 of the machine 2.

[0016] Within each drainage channel 18 a plurality of free movable bodies 20 are positioned having a certain mass. Preferably said bodies are spherical but can also be of other shapes, for example ovoidal, prismatic or polyhedral in general. Moreover, said bodies can be made of different materials, for example metal, in particular steel, or polymer, preferably rubbers or nylon, or stone. In particular, metal material is advantageous in that the bodies 20 wear down only little on their surface; again, polymer material is advantageous in that the noise generated by the movement of the bodies 20 against the metal surfaces 10 and 16 which define the drainage channels 18 is lessened. Faced with this, according to a particularly advantageous embodiment, the bodies 20 consist of a steel sphere covered externally with a nylon layer.

[0017] Each drainage channel 20 is also provided with a discharge aperture 22, these converging into a single manifold 24 positioned external to the machine 2 for transporting the liquid obtained from pressing. Inside each drainage channel 18, at the aperture 22 of each of said channels, an element 26 is provided fixed to a wall of the channel, preferably to the inner wall 16, by supports 28, such that the distance 30 of said element 26 from the opposite surface 10 of the drainage channel is less than the dimensions of the bodies 20. In particular, as is apparent from Figure 3, the distance 30 must be less than the diameter than the spherical bodies 20, this being necessary to prevent these latter being able to enter the aperture 22.

[0018] Essentially, the element 26 defines about the aperture 22 a sort of enclosing fence which compels the bodies 20, driven by the rotation of the drum 4, to pass to the outside of the zone circumscribed by the element 26.

[0019] Preferably the element 26 presents holes 27 for passage of the pressed product flow. In greater detail, the element 26 has greater dimensions than the aperture 22. Moreover, it can be of annular, circular or elliptical shape, but could also be of polygonal shape, for example rhomboidal (see Figure 4); in this latter case, however, to avoid blocking the bodies 20 during the rotation, the sides 29 of the polygon are inclined, not parallel, to the direction of transverse extension of the drainage channel 18.

[0020] The improved machine of the invention operates in the following manner. During the machine working cycle, after the drum 4 has been filled with the product to be pressed, the membrane is inflated, and presses the product against the shell covering 10 of the drum 4 and against the grid 12. The liquid obtained by this pressing operation thus enters the drainage channels 18 and from there begins to flow into the manifold 24 by passing through the apertures 22.

[0021] Subsequently the membrane is deflated by suction created in its interior and the drum 4 is rotated clockwise and anti-clockwise to crumble the pressed product present in the drum in the space left free by the membrane 8. This rotation of the drum 4 also causes the movable free bodies 20 present in the drainage channels 18 to move. In particular, by moving along the surfaces of the drainage channels 18, the bodies 20 prevent the residues from adhering to the surfaces 10 and 16 of said channels, and in addition remove from said surfaces, and in particular from the grids 12, those residues which in any event have managed to adhere to said surfaces.

[0022] Advantageously, elements 32 are fixed to the inner surface 16 of the grid 12, for example by welding, to project from said inner surface 16 to a height less than the free bodies 20. In particular, these elements 32 act substantially as ramps for the free bodies 20, which are hence lifted and urged towards the surface 10 of the rotary drum 4, to then fall again onto the inner surface 16 of the grid 12; this is advantageous in that, following the jump imposed by the elements 32, the bodies 20, on falling, are compelled to enter into contact with the inner surface 16 of the grid 12, hence facilitating cleaning of this latter.

[0023] In particular, as is clear from Figure 4, the elements 32 are aligned with the transverse extension of the annular grid 12 and are suitably distributed along the circumferential extension of said grid.

[0024] Advantageously the elements 32 comprise through apertures 34 in order not to interrupt the liquid flow of pressed product present in the drainage channel 18. In greater detail, as shown in Figure 5, the elements 32 are of inverted E-shape, with their lower ends 36 fixed to the inner surface 16 of the grid 12.

[0025] From the aforegoing it is apparent that the improved machine and the drainage channel cleaning method according to the invention are particularly advantageous in that they maintain the channels clean while also maintaining the grids clean, without substantially requiring the machine to be halted and/or the grid demounted.

Claims

1. An improved machine (2) for pressing fruit or similar products, comprising:

- a cylindrical drum (4) rotating about a central shaft (6),

- a plurality of annular-shaped grids (12) applied to the interior of the drum (4) and spaced therefrom such as to define, with the inner surface (10) thereof, drainage channels (18) each provided with at least one aperture (22) communicating with a manifold (24) connected to the environment external to the machine,

- a membrane (8) wrapped about said central shaft (6) and intended to be selectively inflated in order to press the product against the inner surface (10) of the drum (4) and against said grids (12) such that the liquid obtained by pressing can be collected inside said drainage channels (18),

characterised in that the drainage channels (18) are provided in their interior with a plurality of free bodies (20) intended to be put into movement by the rotation of the machine drum (4), there being provided, to correspond with each aperture (22) of the drainage channels (18), an element (26) which surrounds said aperture (22) and is positioned at a distance (30) from the wall standing in front of the drainage channel (18) which is less than the minimum dimension of said bodies (20).

2. A machine as claimed in claim 1, characterised in that said free bodies (20) are of spherical shape.

3. A machine as claimed in one or more of the preceding claims, characterised in that said free bodies (20) are of polyhedral shape.

4. A machine as claimed in one or more of the preceding claims, characterised in that said free bodies (20) are of metal or of polymer material, or of stone.

5. A machine as claimed in one or more of the preceding claims, characterised in that said free bodies (20) have a core of metal material totally covered with polymer material.

6. A machine as claimed in one or more of the preceding claims, characterised in that at each aperture (22) of the drainage channels (18), said element (26) is positioned at a distance from both the outer wall (10) and the inner wall (16) defining the drainage channel (18), which is less than the minimum dimension of said bodies (20).

7. A machine as claimed in one or more of the preceding claims, characterised in that said element (26) is shaped as an enclosing fence comprising holes (27) for passage of the pressed product.

8. A machine as claimed in one or more of the preceding claims, characterised in that said element (26) is fixed to the inner surface (16) of the drainage channels (18).

9. A machine as claimed in one or more of the preceding claims, characterised in that said element (26) is of annular shape.

10. A machine as claimed in one or more of the preceding claims, characterised in that said element (26) is of polygonal shape with sides (29) inclined to the direction of transverse extension of the drainage channels (18).

11. A machine as claimed in one or more of the preceding claims, characterised in that projecting elements (32) of height less than that of said free bodies (20) are associated with the inner surface (16) of the drainage channels (18), said elements (32) being arranged to cause said free bodies (20) to rise towards the outer surface (10) of the drainage channel (18) following rotation of the drum (4).

12. A machine as claimed in one or more of the preceding claims, characterised in that said elements (32) present holes (34) for passage of the pressed product present in the drainage channels (18).

13. A method for cleaning the drainage channels of a machine for pressing fruit or similar products in accordance with one or more of claims from 1 to 12, characterised in that a plurality of free bodies (20) contained within the drainage channels (18) are caused to move by the rotation of the drum (4) of the machine (2), said bodies (20), by undergoing movement, hit against and rub against the surfaces which define the drainage channels (18), to hence prevent the solid residues from adhering to said surfaces (10, 16), and removing the residues which have managed to adhere to the said surfaces (10, 16).

14. A method as claimed in the preceding claim, characterised in that the rotation of the drum (4) also causes the pressed product contained in the drum to crumble.

Drawing