EP0988230A1

EP0988230A1 - Method and device for dosing a material to be packaged

Info

Publication number: EP0988230A1
Application number: EP99909167A
Authority: EP
Inventors: Alessandro Grazia
Original assignee: Officine Meccaniche Natalino Corazza SpA
Current assignee: Officine Meccaniche Natalino Corazza SpA
Priority date: 1998-04-14
Filing date: 1999-04-09
Publication date: 2000-03-29
Also published as: IL133479A0; AU2851199A; IT1299968B1; PL337444A1; ITBO980238A1; ITBO980238A0; JP2002506410A; WO1999052774A1

Abstract

Method and device for dosing a predefined portion of a material to be packaged, the material being preferably a pasty, semi-liquid or semi-solid material, wherein said material to be dosed is fed within a housing compartment (12), said material is compacted by compressing the material fed in said compartment (12) within a compacting area (12') of said compartment (12), and at least part of the compacted material present in said compacting area (12') is discharged from said compartment (12) thereby realising the predefined dosed portion of material.

Description

1

Description

Method and Device for Dosing a Material to be Packaged

Technical Field

The present invention relates to a method for dosing a predefined portion of a product or material to be packaged, the material being preferably a pasty, semi- liquid or semi-solid material, in particular a foodstuff material, such as for instance the material constituting bouillon cubes or the like.

The present invention further relates to a dosing device that realises the aforesaid method.

Background Art

Prior art devices for dosing pasty material, such as the raw material used to make bouillon cubes, essentially comprise a hopper wherein said material is poured, which feeds the pasty material to a chamber for housing the material itself comprising a section for advancing the material, wherein a metering screw feeder is located which advances and compresses said material within an end accumulation section of the chamber, wherefrom a predefined portion of material is drawn and removed from said chambers by a movable organ for containing the material, which transports the drawn portion of material towards a further work position, where the pre-set portion of material is discharged by said movable container organ, by means of a thrust imparted on said portion of material by an appropriate alternating piston.

To obtain a certain working rate, said prior art devices comprise movable drawing organs, mounted on a rotating support structure, which are alternatively presented to the accumulation chamber and in succession to the discharge piston. The traditional dosing methodology described above, however, is rather inaccurate in its dosage, as it does not guarantee a supply of portions of material having constant weight or at least varying within acceptable weighing tolerances. This problem stems from the fact that this methodology does not allow to guarantee that, upon the detachment for the withdrawal of the material by the movable container organ, the latter is actually in a completely filled condition. It may occur that the container organ, and possibly the entire terminal accumulation section, have not been filled sufficiently or present air bubbles in their interiors, so that the quantity of material drawn is less than the one prescribed for the dosed portion to be packaged.

With current technologies, thrusting within the dosing chamber an excess quantity of material so as to guarantee its filling would present the drawback of producing, within said dosing chamber, an excessive level of pressure which would cause the separation of the fatty part of the raw material used to constitute the bouillon cubes from the remainder of the pasty material, obtaining a final product with non homogeneous constitution and poor quality.

It should also be noted that such known dosing devices are excessively complex and bulky, and this primarily because they require large mechanical parts which are movable externally to the chamber for the realisation of the predefined portion of product to be packaged.

An additional drawback concerns the need to wash the interior part of the device to free it from residues and deposits of the material to be treated. Such a washing, which nowadays constitutes a fundamental requirement for any type of machine operating with foodstuffs in order to guarantee the supply of a hygienically sound product, has not been confronted satisfactorily in known machines, as washing requires the disassembly of the entire device or at least parts thereof. Obviously such disassembly and washing operations must be performed manually and thus require, in addition to an excessive use of manpower, also an overly prolonged machine down time.

Disclosure of Invention

The object of the present invention therefore is to provide a method and a device for dosing a quantity to be packaged of a material, preferably in pasty condition, which allows to overcome the drawbacks present in known similar devices.

The above is attained with a method according to claim 1. In particular thanks to a method for dosing a predefined portion of a material to be packaged, the material being preferably a pasty material, characterised in that said material to be dosed is fed within a housing compartment, said material is compacted by compressing the material fed in said compartment within a compacting area of said compartment, said compacting phase entailing, during said compression, letting the excess material that cannot be housed in this compacting area of said compartment exit said compacting area, and discharging from said compartment at least part of the compacted material present in said compacting area thereby realising the predefined dosed portion of material.

Providing a phase wherein the material is compacted within said compartment through the supply of a superabundant quantity of material inside the compartment, which material is then compacted, compressing the material present in the compartment in a limited area thereof with the free exit from said compacting area of the excess quantity of material beyond the measure that can be contained therein, allows to prevent excessive over-pressures, such as would separate the fatty matter from the remainder of the pasty material, from being produced by effect of the compression. Discharging then said material having an appropriate and desired degree of compacting, and which additionally has not been brought to harmful pressure levels, a dosed portion can be obtained which is extremely precise and has high quality with respect to the dosed portions obtained using the prior art.

The present invention further relates to a dosing device, in particular according to claim 19, realising the present dosing method.

The secondary claims refer to particular and advantageous embodiments of the present invention.

Further features and advantages of the invention shall be made more readily apparent from the content of the detailed description that follows, made with reference to the accompanying drawings, which represent an embodiment provided purely by way of non limiting example .

- Figures 1 through 5 illustrate different operating conditions of the preferred device, schematically shown, realising the dosing method according to the present invention;

- Figure β shows a section view, taken according to line 6-6 of Figure 5, relating to a detail of the housing compartment or chamber and of the dosing piston housed therein of the preferred device of the present invention;

- Figure 7 shows a longitudinal section view taken according to the line 7-7 of Figure 6 relating to an enlarged detail of the central area of the housing compartment of the preferred device of the present invention.

The device 10 that realises the present dosing method essentially comprises, as Figure 1 schematically shows, a housing compartment or chamber 12 obtained within a body 11 of the device, which is supplied with the pasty material 14 by means of appropriate feeding means in the form of a loading hopper 16 fitted with feeder rollers 15 and a possible flow separator 17, with which the pasty material 14 is passed inside the compartment 12 through the opening 18 provided in the upper part of the longitudinal wall of said compartment.

To realise the dosing method, the feeding means operate in such a way as to introduce in said housing compartment a quantity of material that exceeds the quantity of the portion of material to be packaged and the present device further comprises means suitable for compacting within said compartment 12 the material to be dosed, which comprise means 20 pressing said material 14 in a predetermined area 12' of said compartment, and means 22 to let simultaneously flow out, from said compacting area of said compartment, the excess material that does not find housing therein. As shown said pressing means comprise a piston or thrust means 20 slidingly movable within said compartment 12, which, in order to compact the material, is advanced within said compartment until reaching a predetermined compacting position, shown in Figure 2.

The pasty material is compacted in an area 12' of the compartment 12 which is substantially central, wherein the material is held thanks to appropriate shutting means 32, provided in said compartment and acting to intercept the material blocking it on the side opposing the one whereon the compacting thrust is imparted by the dosing piston 20.

During this compacting compression, said feeding opening 18 is closed. According to the present preferred embodiment this is accomplished by the same thrust means 20 by means of the lateral surface of the piston 20 which presents a length suitable to provide such closure.

As Figure 2 shows, according to the preferred embodiment, said material outflow phase for the realisation of the dosed portion entails, in order to make the material exceeding the quantity that can be contained within said compacting area 12' exit said compartment, the use of at least one orifice 22 which opens in said compartment for housing the material, according to the direction of advance of the material, in a position downstream of the predetermined compacting 7 position reached for dosing by said thrusting means 20. The opening of the orifice 22 is established in such a way as to obtain a throttling of the flow of material exiting the compartment by effect of the compression, suitable to provide an appropriate and desired degree of compacting for said material to be dosed.

To control or to maintain a certain degree of compacting of the material as a function of the specific consistency of the pasty material treated, the opening or passage port of said orifice means 22 is adjusted, by adjusting the position of a shutter 24 obtained at the extreme part of an element 26 axially movable in an adjustable manner, by means of a calibration screw (not shown) or other means acting at the other side of the element 26, within a retrieval conduit 28 within which said material is progressively lifted by effect of the material exiting the compartment 12 and wherefrom said excess material is recycled, by means of suitable recirculation means comprising a conveying slide or conduit 30, within said hopper 16 to be re-inserted for feeding to said compartment 12. The terminal part of said conveying slide or conduit 30 ending in said hopper 16 in correspondence with a wall 30' for the separation thereof, which prolongs at the lower part to allow the easy re-entry of the product into the hopper.

Alternatively, the lifting within said recirculation conduit 28 could also be accomplished by a screw feeder acting to lift the excess material exiting the compartment 12 and whose speed of rotation is varied, according to the consistency of the pasty material used, to regulate its flow out of the treatment chamber 12. 8

A sensor 31 is provided on the hopper 16 to sense the level of the pasty material present therein and block the supply of said material to the hopper through the external supply means, exemplified by the conveyor belt 33.

As shown in Figure 3, in succession to the material compacting phase, a discharge assent phase is provided, to accomplish which the present device provides for moving said means 32 for intercepting the material from a position (shown in Figures 1 and 2) upstream of a discharge nozzle 34, held during the feeding and dosing phase, to a position (shown in Figure 3) downstream of the point wherein discharge nozzle means 34 open in said compartment 12. This discharge assent phase further comprises the additional forward displacement of said thrusting piston 20, to be conducted preferably simultaneously with said shutting means 32, until reaching an advanced position suitable to position the compacted mass of material to be discharged in correspondence with said discharge nozzle means 34, as shown in Figure 3.

According to a further feature, upon the occasion of said phase of advance of the compacted material in correspondence with said nozzle means, the exit of the material from said orifice means 22 is closed, by the thrusting means 20 itself with the lateral surface of the piston 20. During this further phase of advance of the thrusting piston 20, the opening 18 for the introduction of the material inside the compartment 12 is kept closed by the rear lateral surface of the piston 20.

Further provided are means to discharge said predefined portion from said compartment 12. Said discharging means comprise means 36 acting by thrusting on the compacted material to discharge it from the housing compartment through said nozzle means 34. The discharge stroke of said thrusting means 36 determines the desired dosed portion which, being obtained by operating on a suitably compacted material, presents a high degree of precision.

As shown, said compartment 12 for housing the material comprises a main part 12a wherein the material is introduced during the feeding phase and wherein the material, indicated as 14a, is compacted and a secondary part 12b within which during the compacting operation a secondary part 14b of said material is compressed. As shown, said main part 12a of the compartment 12 comprises a cylindrical chamber extending longitudinally and said secondary part 12b of the compartment 12 also comprises a cylindrical chamber extending longitudinally in parallel to said main chamber and separated therefrom by means of an intermediate wall 12c. Said secondary part of the compartment 12b presents a curved forward terminal section 12' b for the junction and insertion, through a port 38, into said first part 12a of the compartment 12.

As shown according to the present embodiment, the pistons 20, 32 for compacting and intercepting the material are positioned within the main part of the compartment 12a prolonging and being activated starting from opposite longitudinal ends of said compartment 12, while the dosing and discharging piston 36 in turn extends in the secondary part 12b of the compartment 12 and it is activated by the same side wherefrom said 10 compacting piston 20 extends in the main part 12a of the compartment 12.

Said port 38 for connecting the secondary branch 12b with the main branch 12a of the chamber 12 is located downstream of said orifice means 22 on the side of the chamber opposite to the one occupied by said orifice means and by said feeding opening 18. As shown, said thrusting means 20 after advancing the compacted material in correspondence with the ejection nozzle 34, position themselves in correspondence to, in particular slightly upstream of, said connecting port 38.

Said means 36 acting to thrust on the compacted material to effect the discharge are movable between a rear position (shown in Figure 3) , which is maintained during the compacting operation, and an advanced discharge position (shown in Figure 4) wherein they act thrusting against the secondary portion of material 14b present in this secondary part 12b, causing the exit (as shown in Figure 4) of the pre-set dosed portion of the nozzle 34 towards the packaging.

The normal operation of the device therefore entails, cyclically, a first phase, shown in Figure 1, whereby the pasty material is fed into said housing compartment 12 by means of the hopper 16, followed by a second phase (shown in Figure 2) whereby the piston 20 advances to close the opening 18 for feeding the material to the compartment 12 and reaches a first working position wherein the compacting operation is effected and during which the material in excess is ejected through the orifice 22, suitably adjusted, and then recirculated within the feeding hopper 16. 11

In a third phase shown in Figure 3, the material is moved in correspondence with the outlet 34, by moving the piston 32 for intercepting the material downstream of the inlet of the discharge nozzle 34 and further advancing the rear thrusting piston 20 until arriving, in a second working position, in correspondence with the port 38 connecting the main part 12a of the chamber with the secondary part 12b. Once this phase of Figure 3 is completed, the compacted material is ready to be discharged.

Discharge is effected, in a fourth phase that entails, as shown in Figure 4, the advancement and thrusting on the material by the discharging and dosing piston 36 which, flowing within the secondary part of the compartment, thrusts the compacted material to the rear and forces it to exit the nozzle 34 towards the packaging.

Having completed this phase, the pistons 20, 32, 36 are brought back in the respective initial positions shown in Figure 1 ready to repeat the previously described work phases.

With reference also to the subsequent figures 5, 6 and 7, it can be noted that the pistons 20, 32, 36 present respective extreme portions to engage the material 20a, 32a, 36a having a cross section whose outer peripheral profile matches with and slidingly contacts the profiles of the cross section of said compartment 12 and respective stem portions 20b, 32b, 36b supporting said extreme portions for engaging the material 20a, 32a, 36a. As shown, the front faces of the pistons 20, 32, 36 that engage the material are provided inclined with 12 respect to the direction of motion of the material in such a way that by moving back a certain detachment is possible from these faces of the treated pasty material. For the circulation of a detergent or cleansing fluid within said compartment 12 appropriate passage means 40, 42 are provided in correspondence with said compartment 12, which allow the fluid to flow beyond the extreme portions 20a, 32a, 36a for engaging the material of said pistons 20, 32, 36, in such a way as to allow the passage of the detergent or cleansing fluid between the areas upstream and downstream of the respective extreme portions 20a, 32a, 36a for engaging the material.

The stem portions 20b, 32b, 36b are provided with respective longitudinal groove means 20c, 32c, 36c which can be placed in fluid communication with the corresponding passage means 40, 42 to allow the circulation of said detergent or cleansing fluid in the compartment 12.

The stem portions 20b, 32b, 36b of the pistons 20, 32, 36 preferably present a polygonal section, in particular, as shown in Figure 6 relatively to piston 20 alone, a triangular section having vertices or edge portions 20d, 20d, 20d for contacting and sliding against the inner surface of said compartment 12, between which are defined, delimited between the longitudinal lateral faces 20e, 20e, 20e and the inner cylindrical wall of the compartment 12, respective longitudinal grooves 20c, 20c, 20c for the passage and linear conveyance of the detergent or cleansing fluid. According to the preferred embodiment shown herein, first passage means 40 are provided in the main part 12a 13 of said compartment 12 in a median position thereof in correspondence with which are positioned said compacting piston 20 and said intercepting piston 32 in such a way that an individual means 40 can provide for the passage of washing or cleansing fluid beyond both portions 20a, 32a for engaging said pistons 20, 32. Said passage means 40 are provided in the main part 12a of said compartment 12 in correspondence with said connecting port 38 between the parts 12a and 12b of the compartment 12, and second passage means 42 are provided in the secondary part 12b of said compartment 12 in proximity with the connecting port 38.

As shown in particular by Figures 6 and 7, according to the preferred embodiment shown herein said passage means 40 and, equally, said passage means 42, are in the form of a circumferential widening of the cross section of said compartment 12 that extends longitudinally for a certain section of the compartment or chamber 12.

With the present device it is possible periodically to effect, after a number of predetermined dosage cycles, a washing or cleansing process of the device.

The washing and cleansing process provides for positioning each piston 20, 32, 36 in correspondence with the respective means 40, 42 for the passage of the washing or cleansing fluid, and for making said washing and cleansing fluid circulate within said compartment 12 in particular in the form of a liquid material.

In particular, as shown in Figure 5, the washing or cleansing process of the device provides for positioning said thrusting and intercepting pistons 20, 32 of the material within the main part of the compartment 12a 14 approached one in front of the other in coincidence with said section widening in correspondence with said port 38 for connecting the secondary part 12b with the main part 12a of the housing compartment, whilst the discharge thrusting piston 36 is positioned, within said secondary part 12b of the compartment, in correspondence with said section widening provided in proximity with said connecting port 38. Moreover, for the washing or cleansing, said orifice means 22 are fully opened, in such a way that said washing or cleansing fluid can circulate, as shown by the arrows in Figure 5, along the whole inner part of the device which is in contact with the treated material, sliding within said chamber 12, along the grooves 20c, 32c, 36c of the pistons, and within the ascent conduit 28 along the slide 30 and the inner parts of the hopper 16. As shown in Figure 5, according to the preferred embodiment the washing or cleansing liquid is introduced, by appropriate means 50, into the device through the hopper 17. In this way it is possible to effect the washing and the possible cleansing of the inner surfaces of the device in contact with the pasty material without needing to provide for the disassembly of the device.

The actuation of the various movable organs, such as the pistons, of the device is governed by actuation and control means of a wholly known kind. It is not necessary, therefore, to describe it in detail herein.

The invention thus conceived may be subject to numerous modifications and variations, without thereby departing from the scope of the inventive concept. Moreover, all components can be replaced with technically 15 equivalent elements.

Claims

16Claims

1. Method for dosing a predefined portion of a material to be packaged, the material being preferably a pasty material, characterised in that said material to be dosed is fed within a housing compartment (12), said material is compacted compressing the material fed in said compartment (12) within a compacting area (12') of said compartment (12) , said compacting phase providing, during such compression, for letting the excess material that cannot be housed in said compacting area (12') of said compartment (12) exit said compacting area (12'), and discharging from said compartment (12) at least part of the compacted material present in said compacting area (12') in such a way as to realise the predefined dosed portion of material.

2. Method according to claim 1, characterised in that said phase whereby the material is compressed in order to compact the predefined portion is effected by movable means (20) for thrusting said material in said compartment (12), which thrusting means (20) for realising a predefined compacting operation are advanced within said compartment (12) until reaching a predetermined compacting position.

3. Method according to claim 2, characterised in that in said phase whereby the material is compressed for compacting the material, the feeding of the material to said housing compartment (12) is interrupted by the advance of said movable thrusting means (20) . 17

4. Method according to any of the previous claims from 1 to 3, characterised in that said exit phase provides for making the excess material flow out of said compacting area (12') through orifice means (22) opening in said housing compartment (12) in correspondence with the area destined to the compacting operation (12').

5. Method according to claim 4, characterised in that said orifice means (22) open in said housing compartment (12), in the sense of advance of the material, downstream of the predetermined position reached for the compacting operation by said thrusting means (20 ) .

6. Method according to either of the previous claims 4 and 5, characterised in that the passage of the material through the orifice means (22) is adjusted as a function of the consistency of the treated pasty material .

7. Method according to any of the previous claims from 1 to 6, characterised in that said excess material exited from the compartment (12) during the compacting operation is reinserted to be fed to the housing compartment (12) .

8. Method according to any of the previous claims, characterised in that the discharge of the dosed portion from said compartment (12) takes place through nozzle means (34) opening in said compartment (12), in that after said compacting phase, a phase of assent to the 18 discharge of the material is provided, and in that said phase of assent to the discharge entails moving means (32) for intercepting the material, within said compartment (12) , from a position wherein assent to the discharge is not provided to a position of assent to the discharge of the material through said nozzle means (34) .

9. Method according to claim 8, characterised in that said position of non-assent to the discharge of said means (32) for intercepting the material is held during the material feeding and compacting phase and is located upstream of the point wherein said discharging nozzle means (34) open in said compartment (12), and in that said position of assent to the discharge of said means (32) for intercepting the material is located downstream of the point wherein said discharging nozzle means (34) open in said compartment (12) .

10. Method according to claim 9, characterised in that said discharge assent phase entails moving said compacting thrusting means (20) to a further advanced position such as to move compacted material in correspondence with said discharging nozzle means (34) .

11. Method according to claim 10, characterised in that said movement of the compacting thrusting means (20) and said movement of the intercepting means (32) takes place simultaneously.

12. Method according to claim 10 or 11, characterised in that, during said phase of advance of the material in 19 correspondence with said nozzle means (34), the exit of the material through said orifice means (22) is closed.

13. Method according to claim 12, characterised in that said phase whereby the orifice means (22) are closed is effected by the same compacting thrusting means (20) during the advance to execute the displacement of the compacted material in correspondence with said nozzle means (34) .

14. Method according to any one of the previous claims, characterised in that means (36) acting by thrusting on the compacted material are provided to discharge a dosed portion from the housing compartment (12) through said nozzle means (34).

15. Method according to claim 14, characterised in that said material housing compartment comprises a main part (12a) wherein the material is introduced, during the feeding phase, and wherein the material is compacted, and a secondary part (12b) , in communication with the main part (12a) through port means (38), wherein, during compacting, a secondary portion of said material is compressed; and in that said thrusting means for discharge and dosage (36) are movable in this secondary part (12b) of said compartment (12) , acting by thrusting against the secondary portion of material present therein, between a rear position, held during the compacting operation, and an advanced position for dosing. 20

16. Method according to claim 15, characterised in that the advanced position of the compacting thrusting means (20) , for the placement of the predefined quantity of material in front of said discharge nozzle means, is located in correspondence with said connecting port (38), immediately upstream of the connecting port (38) itself.

17. Method according to any one of the previous claims, characterised in that the housing compartment (12) comprises a main cylindrical chamber (12a) which extends longitudinally.

18. Method according to claim 17, characterised in that the housing compartment (12) comprises a second cylindrical chamber (12b) extending parallel to said main chamber (12a) .

19. Device for dosing a predefined portion of a material to be packaged, the material being preferably a pasty material, characterised in that it comprises a compartment (12) for housing the pasty material, means

(16) for feeding the material to be packaged within said housing compartment (12) , means for compacting said material comprising means (20) able to compress the material fed in said compartment (12) within a compacting area (12') of said compartment (12) and means (22) for the exit from said compacting area (12' ) , during the compression, of the excess material that cannot be housed in this compacting area (12'), and means (34,36) for discharging from said compartment (12) at least part of the compacted material present in said compacting area 21

(12' ) in such a way as to realise the predefined dosed portion of material.

20. Device according to claim 19, characterised in that said compression means for compacting comprise movable means (20) for thrusting said material in said compartment (12) , which thrusting means (20) for realising the predefined quantity are advanced in said compartment (12) until reaching a predetermined compacting position.

21. Device according to claim 20, characterised in that said movable thrusting means (20) close, during said phase wherein the material is compressed to compact the predefined portion, the opening (18) for the access of the material to said housing compartment (12) .

22. Device according to any of the previous claims from 19 to 21, characterised in that said means for the exit of the excess material comprise orifice means (22) through which the material flows out of said compartment (12) , said orifice means (22) opening in said compartment (12) for housing the material in correspondence with the area (12') whereof where the compacting action takes place.

23. Device according to claim 22, characterised in that said orifice means (22) open in said housing compartment (12) , in the direction of advance of the material, downstream of the predetermined compacting position reached for compacting by said thrusting means 22 ( 20 ) .

24. Device according to either of the previous claims 22 and 23, characterised in that means (24) are provided for regulating the passage of the material through the orifice means (22) as a function of the consistency of the pasty material treated.

25. Device according to any of the previous claims from 19 to 24, characterised in that means (30) are provided for feeding back to the housing compartment (12) said excess material exited during the compacting operation.

26. Device according to any of the previous claims from 19 to 25, characterised in that for the discharge of the dosed portion from said compartment (12) nozzle means (34) are provided which open in said compartment (12), in that to provide assent to the discharge, means (32) for intercepting the material, inside said compartment (12) , are moved from a position wherein assent to the discharge is not given to a position of assent to the discharge of the material through said nozzle means (34) .

27. Device according to claim 26, characterised in that said position of not assent to the discharge of said means (32) for intercepting the material is held during the material feeding and compacting phase and is located upstream of the point wherein said discharge nozzle means (34) open in said compartment (12), and in that said position of assent to the discharge of said means (32) 23 for intercepting the material is located downstream of the point wherein said discharge nozzle means (34) open in said compartment (12) .

28. Device according to claim 27, characterised in that said compacting thrusting means (20) , during said discharge assent phase, are moved into a further advanced position, such as to move the compacted material in correspondence with said discharge nozzle means (34) .

29. Device according to claim 28, characterised in that said movement of the compacting thrusting means (20) and said movement of the intercepting means (32) occurs simultaneously.

30. Device according to claim 29 or 30, characterised in that said thrusting means (20) , when they advance to execute the movement of the material in correspondence to said nozzle means (34), close said orifice means (22).

31. Device according to any of the previous claims from 19 to 30, characterised in that means (36) are provided acting by thrusting on the material to effect the discharge of the predetermined dosed portion from the housing compartment through said nozzle means (34) .

32. Device according to claim 31, characterised in that said compartment (12) for housing the material comprises a main part (12a) wherein the material is introduced during the feeding phase and wherein the material is compacted and a secondary part (12b) , in 24 communication with the main part (12a) through port means (38), within which during the compacting action a secondary portion of said material is compressed, and in that said discharge and dosage thrusting means (36) are movable in this secondary part (12b) , acting by thrusting against the portion of material present therein, between a rear position held during the compacting operation and an advanced, dosing, position.

33. Device according to claim 32, characterised in that said advanced position of the compacting thrusting means (20) for placing the predefined quantity of material in correspondence with said discharge nozzle means is located in correspondence with said connecting port (38) of the secondary part (12b) of the compartment in the main part (12a) , immediately upstream of the connecting port itself (38) .

34. Device according to any of the previous claims from 19 to 33, characterised in that the housing compartment (12) comprises a main cylindrical chamber (12a) extending longitudinally.

35. Device according to claim 34, characterised in that the housing compartment (12) comprises a second cylindrical chamber (12b) extending parallel to said main chamber (12a) .

36. Device according to any of the previous claims from 20 to 35, characterised in that said thrusting means for compaction and advancement (20) are in the form of a 25 respective piston (20) able to slide linearly in said compartment (12) .

37. Device according to any of the previous claims from 20 to 36, characterised in that said means (32) for intercepting said material are in the form of a respective piston (36) able to slide linearly within said compartment (12).

38. Device according to any of the previous claims from 27 to 37, characterised in that said thrusting and discharging means (36) are in the form of a respective piston (32) able to slide linearly within said compartment (12) .

39. Device according to any of the claims from 36 to

38, characterised in that the piston (20 or 32 or 36) presents at least an extreme portion (20a or 32a or 36a) for the engagement of the material having a cross section whose outer peripheral profile matches and contacts with sliding the inner transverse profile of said compartment (12) .

40. Device according to claim 39, characterised in that for the circulation of a detergent or cleansing fluid within said compartment (12) , within said compartment (12) are provided passage means (40, 42) able to extend beyond at least the extreme portion of the engagement of the material (20a or 32a or 36a) of a corresponding piston (20 or 32 or 36) to allow the passage of the detergent or cleansing fluid at least 26 between the areas upstream and downstream of the corresponding extreme portion of the piston for the engagement of the material (20a or 32a or 36a) .

41. Device according to claim 39 or 40, characterised in that the piston (20 or 32 or 36) presents a stem portion (20b or 32b or 36b) which presents at the end said extreme portion for the engagement of the material, which stem portion (20b or 32b or 36b) is provided with longitudinal groove means (20c or 32c or 36c) which can be placed in fluid communication with corresponding passage means (40, 42) to allow the circulation of said detergent or cleansing fluid.

42. Device according to claim 41, characterised in that said stem portion (20b or 32b or 36b) presents a cross section with polygonal shape having vertices (20d) contacting and sliding against the inner surface of said compartment (12), between which vertices are defined respective longitudinal grooves (20c or 32c or 36c) for the passage of the detergent or cleansing fluid.

43. Device according to claim 42, characterised in that said stem portion (20b or 32b or 36b) presents a triangular cross section.

44. Device according to any of the claims from 40 to 43, characterised in that said passage means (40) are provided in the main part (12a) of said compartment (12) in a median position thereof, said compacting piston (20) and said intercepting piston (32) being positioned, on 27 the occasion of the washing operation, with the respective extreme engagement portions (20a, 32a) closely positioned one in front of the other in correspondence with said passage means (40) in such a way as to provide for the passage of washing or cleansing fluid beyond both said engagement portions (20a, 32a) of said pistons (20, 32) .

45. Device according to claim 44, characterised in that, on the occasion of the washing or cleansing operation, the extreme engagement portions (20a, 32a) of said compacting piston (20) and of said intercepting piston (32) are positioned in correspondence with said passage means (40) located in coincidence with said connecting port means (38); in that said dosing piston

(36) is positioned with its own engagement portion (36a) in correspondence with second passage means (42) provided in the secondary part (12b) of said compartment (12) in the vicinity of said connecting port means (38); and in that said orifice means (22) are left completely open, so that said washing or cleansing fluid can circulate freely inside the compartment (12) through the groove means

(20c, 32c, 36c) and the other surfaces of the device that come in contact with the treated material.

46. Device according to any of the previous claims from 40 to 45, characterised in that said passage means (40, 42) are in the form of a widening of the cross section of said compartment (12) .

47. Device according to any of the previous claims from 28

19 to 46, characterised in that said pistons for thrusting and intercepting (20, 32) the material are positioned within the main part of the compartment (12a) extending from opposite ends of said compartment (12) .

48. Device according to claim 47, characterised in that said dosing and discharging piston (36) extends in the secondary part (12b) of the compartment (12) on the same side whereto said compacting piston (20) extends in the main part (12a) of the compartment (12) .