Displacement dosing device and relative moving apparatus The present invention relates to a displacement dosing device, in particular a device for dosing fixed and exact amounts of liquid, suitable for the use in pharmaceutical, cosmetic, food field.

The invention concerns as well a moving apparatus suitable ford actuating said dosing device and similar others. In pharmaceutical and food field it is known to use piston displacement pumps, installed on automatic packaging machines for filling containers, such as phials, syringes, capsules, cruets and similar, with liquid products having variable viscosity.

In such devices, the piston translates with alternating motion within a cavity or dosing space made in a tubular cylindrical hollow body. The stroke of the piston enables a fixed volume of liquid to be sucked and then supplied, which is function of the same stroke and the diameter of the cavity of the cylinder. The dosing space exhibits inlet and outlet openings connected respectively with an intake duct and a discharge duct of the liquid to be dosed. Stop valves are provided externally on said ducts for alternatively open and/or close said ducts during operation of the pump. Some dosing devices in substitution of the external valves comprise commutating means, placed inside the dosing space of the cylinder and controlled so as to connect said dosing space alternatively with the intake ducts and the discharge ducts, in phase with the rectilinear motion of the piston. Such commutating means may consist of a rotating valve inserted in the dosing space, suitable for opening and closing the inlet and outlet openings.

Alternatively, dosing devices are known wherein , the commutating means are obtained on the piston self which, besides to slide axially, • may rotate around its own longitudinal axis of translation for a prefixed angle, so as to place in communication the dosing space alternatively with

the intake duct and the discharge duct.

Such piston, commonly called "piston-valve, in order to collect said feeding duct with the dosing space", exhibits, in fact, a cavity that during the intake phase is faced to the feeding duct. The intake stroke of the piston determines a volume increase of the dosing space and consequently the suction of liquid from the feeding duct.

At the end of such stroke the piston-valve is rotated so that the cavity corresponds with the discharge duct, in order to enable the piston, during the return stroke or dosing stroke, to deliver the predefined amount of fluid.

Once the stroke ended, the piston is brought again in the starting angular position and the disclosed dosing cycle can start again. Generally the devices disclosed above comprise an upwards open cylinder for enabling a piston-valve to be introduced from above, provided with an upper end protruding from the cylinder, suitable for being connected with proper actuating members that provide for the rotation and translation of said cylinder.

One of the main problems to be solved in designing and manufacturing this type of dosing devices lies in the removal or discharge of the air present inside the cylinder during the initial phase of arming or starting up the pump. In order to completely fill with liquid the dosing space of the pump, the air present in said dosing space has to be able to exit. The presence of air within the pump is unacceptable because- said air affect the regular operation, compromising the dosing accuracy. In order to solve this problem, the known dosing devices during the starting phase are generally "armed" that is filled with liquid with manual or semi-automatic procedures, by means of which the air present in the dosing space is discharged. Such procedures, besides being time-consuming and arduous, involve a remarkable amount of liquid product to be supplied

condemned to be discarded from the production since delivered in the containers in incorrect doses or because subsequently mixed with the air. In the case of expensive pharmaceutical products, such waste is considered disadvantageous. Besides this, such procedures require the intervention of one or more operators .

In many applications, mainly in pharmaceutical and food field, it is further required that the dosing devices can be subjected to on site washing and sterilizing operations, without the need of dismounting any components thereof. Such operations, known with the term of CIP/SIP (Cleaning In Place / Sterilizing In Place) , consist substantially in a sequence of steps, suitable for being carried out in automatic or semi-automatic manner, in the course of which the interior of the dosing devices is passed through by washing fluids at different temperatures and by pressurized vapor. Thus, in relatively short times, all the parts come into contact with the product can be washed and sterilized. It is essential condition for the correct and effective implementation of a CIP/SIP washing and sterilizing procedure is that any internal surface of the device, that is in contact with the product, is conveniently reached and licked with the necessary flow speed by the washing and sterilizing fluids . Besides this, Ia structure and conformation of the device must assure the correct drainage and discharge of such fluids at the end of the washing and sterilizing cycles, i.e. the absence of point where said fluids can accumulate and stagnate. The known dosing devices are associated with dosing/filling machines generally grouped together in variable number, so as to feed a plurality of respective filling noses of containers . Supporting frames provide to support the dosing devices and, above said dosing devices, the actuating members of the pistons, said members being accommodated within suitable

containers .

The actuating members comprise motors, transmission mechanisms and linkages, sensors, etc. that, for reasons of cleanliness and hygiene must be separated from the environment where packaging of the product occurs.

In the case that said dosing groups are mounted on a dosing machine operating in aseptic and sterile environment, it is noted that the dimensions and the position of said containing casings of the actuating members can cause some disadvantages .

The sterility of the packaging environment of the products is assured, among other things, by the presence of a proper sterile flow of filtered air, that vertically flows from top to down with steady-state unidirectional and uniform motion, in particular at the operating regions, where for example dosing of the product in the containers occurs. The air flow gives rise to a sterile air front that licks the containers and drags along towards the bottom contaminant particles possibly present in the environment. The air flow further prevents such particles from being able to rise again from the bottom towards the top and enter the containers, so as to contaminate them.

The dimensions of the casings enclosing the actuating members and mainly their superelevated position with respect . to the dosing devices perturb the unidirectional and uniform flow of the air and force the set of the dosing devices to be positioned as far as possible from the dosing region. When this is not possible, for example due to the transversal dimensions of the dosing machine, a deviation and alteration of the air flow arises in said dosing region.

Besides this, due to the movements of translation and rotation of the pistons of the dosing devices and the pumps, particles may be generated that can be drained by the air flow into the underlying containers . The presence of mechanical members and components within the sterile region implies the need to interrupt the sterility in

the case that failures or breakage occur of said mechanical members and components for enabling servicing operations . That implies long stop times and high costs for restoring, after maintenance, the proper required conditions of sterility.

Dosing devices are known in which the piston can be actuated from below, its mounting end protruding downwards from the cylinder. However for enabling the air to properly flow out from the dosing space of the cylinder at the starting phase, said devices require laborious procedures of manual filling and can be installed only in inclined position. In the case that said devices have to be installed on a packaging machine, their inclined arrangement implies an increase of the volumes and therefore remarkable restrictions of structural and manufacturing type, mainly in the case of applications in aseptic/sterile environment.

The known piston displacement pumps are made generally of stainless steel, material that is suitable for contact with pharmaceutical and food products and may be subjected to washing and sterilizing procedures.

Use is further known of ceramic materials owing to which components can be realized that show narrow dimensional tolerances and reduced values of surface roughness . The ceramic materials exhibit very high strength coefficients to wear and high temperatures and very limited thermal expansion coefficients. Said properties make the ceramic materials particularly indicated for realizing piston pumps of high precision and predisposed for washing and sterilizing CIP/SIP procedures . The ceramic materials exhibit however limitation in mechanical field, because are substantially brittle easily susceptible to breakage, fractures, chipping.

For this reason the cylinders of the pumps made of ceramic material are covered by a metallic jacket, typically of stainless steel. Said metallic jacket is- mounted by expansion fit with interference, so as to form with the ceramic

cylinder a monolithic single body.

The external metallic casing besides to protect the internal ceramic cylinder, enables the pump to be fixed to a supporting frame and the mounts of the ducts for suction, discharge and drainage to be connected with said pump.

However, the unremovable and irreversible interference coupling between ceramic cylinder and steel jacket exhibits some disadvantages . It is actually possible that, due to a non optimal coupling, in the interface region between ceramic cylinder and metallic jacket slots, splits, interspaces are present of microscopic dimensions but sufficient for allowing seepage and diffusions of liquids, such as products to be dosed, washing and sterilizing liquids. In that case, it is not possible to provide to a correct and complete cleaning, because the cylinder-jacket assembly is not dismountable .

Besides this, in case of breakage or wear of the ceramic cylinder, also the jacket has to be substituted, with consequent increase of the costs . An object of the present invention is to improve the known displacement dosing devices.

Another object is to realize a device permitting an accurate and exact dosing in a wide range of filling volumes and enabling an efficient and complete discharge of the air in automatic manner, in particular during the starting stage.

A further object is to obtain a dosing device wherein the piston can be actuate from below, so that the respective moving means is arranged below the apparatus self. Other object is to realize a dosing device configured and suitable for washing and sterilizing operations of CIP/SIP type.

Further object is to obtain a device that is totally dismountable, in rapid and easy manner for enabling all the components thereof to be completely and exhaustively cleaned. In a first aspect of the invention a device is provided for dosing amounts of liquid in desired volumes, comprising

piston means movable in a cavity of casing means in order to collect an amount of liquid from an inlet of said casing means and direct said amount of liquid towards an outlet of said casing means, said piston means being provided with commutating means such to selectively make communicating said cavity with said inlet or with said outlet, said commutating means being provided with an operating end suitable for being faced with at least said outlet in order to define with said outlet an outflow wall such to inhibit the adhesion of possible air bubbles .

Owing to this aspect of the invention a dosing device can be obtained that enable an efficient and complete discharge of the air in automatic manner during the starting stage. The operating end of the commutating means and the outlet of the casing means are actually coincident with the highest point of the internal cavity, i.e. the point where possible air bubbles could collect. Furthermore, the commutating means of the piston means comprises a longitudinal channel configured for realizing with said outlet a discharge duct the shape and dimensions of which facilitate the air bubbles to spontaneously flow out of and prevent said air bubbles from stagnating within the cavity.

The particularly accurate and exact surface finish of the surfaces of the cavity and the piston means contribute the possible bubbles to be prevented from adhere.

Owing to the presence of particular longitudinal grooves on the side walls of the cavity of the casing means cooperating during the operation with said commutating means of the piston means, said piston means may be translationally and rotationally operated by moving means arranged below the device .

In particular, the moving means is connected with a lower end of the piston means, protruding from below from the cavity of the casing means. In a second aspect of the invention a device is provided for dosing amounts of liquid in desired volumes, said device

being provided with piston means movable in a cavity of casing means and comprising covering means suitable for removably containing said casing means.

Owing to this aspect of the invention a device for dosing can be realized wherein the casing means, made for example of ceramic material, is contained, protected against possible breakage, fractures, chipping, inside covering means, of metallic material, for example stainless steel. In particular, the covering means comprises two jackets configured for containing respective upper and lower portions of the casing means, said jackets being mutually removably connected by fixing means. That enables the device to be rapidly, easily and completely dismounted, in order to provide for a correct and detailed cleaning of the single components of the device. Namely, all the surfaces of said components can be accessed, slots, splits, interspaces of the interface region between .the casing means and the jackets of the covering means being made accessible for cleaning. The possibility of dismounting the covering means from the casing means enables said covering means to be substituted in case of failure, damage, wear.

The covering means properly configured enables as well the device of the invention to be made suitable for washing and sterilizing operations of CIP/SIP type. In a third aspect of the invention a apparatus is provided for moving a dosing device, comprising first actuating means and second actuating means suitable connectible with a lower portion end of piston means of said device in order to linearly and rotationally move said piston means. Owing to this aspect of the invention a moving apparatus for dosing devices can be realized suitable for being actuated from below that may be arranged internally below said devices and accommodated within a containing volume suitable for being hermetically separated from the processing environment, for example the sterile dosing environment. Thus, it is possible to lightly and rapidly intervene on mechanical

members and components of the apparatus for servicing and/or repairing operations, without having to transit through the processing environment, compromising the sterility of said processing environment . Furthermore, since the moving apparatus is arranged below the dosing devices, said moving device does not perturb a unidirectional vertical air flow in the case present in the processing environment, in particular, at an overhanging operating region, wherein for example dosing takes place. Because the connections between the moving apparatus and the piston means of the dosing devices are also positioned below the operating region, possible particles or extraneous bodies that can be generated by the movements of translation and rotation of the piston means are dragged downwards by the air flow, without being capable of rising again and involve said operating region.

The invention can be better understood and carried out with reference to the enclosed drawings, that illustrate an exemplifying and not restrictive embodiment thereof, wherein: Figure 1 is a longitudinal section of the displacement dosing device of the invention, highlighting piston means in a first operating position of suction start stroke and, with dotted line, in a fourth operating position of discharge end stroke; Figure 2 is a section like Figure 1, highlighting the piston means respectively in a second operating position of suction end stroke and, in dotted line, in a third operating position of discharge start stroke;

Figure 3 is a partial enlarged section like Figure 1, highlighting an operating end of commutating means of the piston means,-

Figure 4 is an enlarged cross section according to a plane IV-IV of Figure 1;

Figure 5 is a longitudinal section of a version of the device of Figure 1, wherein the piston means are in a fifth washing and sterilizing operating position;

Figure 6 is a partial schematic section of moving means of

the device of Figure 1 associated with a frame of a packaging machine ;

Figure 7 is a front view, partially sectioned, of the moving means of Figure 6 with a plurality of devices of Figure 1. With reference to Figures 1 to 4, a device is shown for dosing amounts of liquid in desired volumes, comprising piston means 3 moving in a cavity 4 of casing means 2 for collecting a desired amount of liquid from an inlet 12 of said casing means 2 and directing said desired amount of liquid toward an outlet 13 of said casing means 2.

The piston means 3 are provided with commutating means 8 such to make selectively communicating the cavity 4 with the inlet 12 or with the outlet 13 and provided with an operating end 8a suitable for being faced at least to said outlet 13 for defining with said operating end 8a- an outflow wall such as to prevent possible air bubbles from adhering and becoming stagnant, in particular during the starting or "turn-on" step of the device. The piston means 3 are moving with alternating translating motion between a withdrawn or internal position and an extended or external position, and moving with as well alternating rotating motion, between an intake position, wherein the commutating means 8 places in communication the cavity 4 with the inlet 12 and a discharge position, wherein said commutating means 8 connects said cavity 4 with the outlet 13. Substantially, the piston means 3 is moving between four different operating positions, as explained in detail in the operation of the device. The cavity 4 of substantially cylindrical shape extends longitudinally over the full length of the casing means 2, comprising a tubular, also substantially cylindrical element. The cavity 4 is comprised of a lower chamber 4a and an upper chamber 4b, having different diameters and length. In particular, the lower chamber 4a exhibits a greater diameter than the upper chamber 4b.

The upper chamber 4b of the internal cavity 4 is in flow

communication with an intake duct 30 and with a discharge duct 31 of the liquid product to be dosed, respectively via said inlet 12 and said outlet 13, consisting of respective holes made on the tubular wall of said upper chamber 4b. The inlet holes 12 and the outlet holes 13 are arranged at the same level or height with reference to a longitudinal axis Z of the device 1, said axis Z being coincident with the translation direction of the piston means 3. The inlet holes

12 and outlet holes 13 are mutually angularly spaced apart for an angle ranging between 30° and 180°, for example 120°

(Figure 4) .

Said holes are further made virtually orthogonal to the tubular wall of the upper chamber 4b.

The internal wall of the upper chamber 4a exhibits a first groove 9 and a second groove 10, longitudinal, of elongate shape and substantially parallel to the longitudinal axis Z.

Said grooves 9, 10 extend towards the lower chamber 4a starting respectively from the inlet 12 and the outlet 13..

The piston means 3 consists substantially of a cylindrical elongate body comprising three portions coaxial with the longitudinal axis Z and having different diameters and lengths .

The piston means 3 comprises an upper end portion 7, an intermediate portion 6 and a lower end portion 5. This latter is configured for exiting out of the lower chamber 4a of the casing means 2 in order to enable to be connected with moving means suitable for to transmitting the movement to the piston means 3.

The intermediate portion 6 of the piston means 3 is predisposed. for tightly sliding within the lower chamber 4a, whereas the upper portion 7 is configured for tightly sliding , within the upper chamber 4b. Thus, the diameter of the intermediate portion 6 is greater than the diameter of the upper portion 7. The hydraulic tightness between the portions 6, 7 of the piston 3 and the respective chambers 4a, 4b is accomplished

owing to the reduced clearances between the walls of said portions and said chambers, said clearances enabling sliding without friction of the piston 3, but excluding the passage of the liquid to be dosed. The commutating means 8 comprises an elongate longitudinal channel, virtually parallel to the longitudinal axis Z of the device 1 and made in the upper end portion 7 of the piston 3. The channel 8 is adapted for selectively matching the first groove 9 or the second groove 10 and placing in communication the lower chamber 4a respectively with said inlet 12 or said outlet 13, as a function of the angular position of the piston 3.

In particular, said channel 8 comprises, besides said operating end 8a designed for being faced to said inlet 12 and said outlet 13., a further operating end 8b, configured for conveying the liquid in the lower chamber 4a, and an intermediate connecting portion 8c of the two operating ends 8a, 8b. Said intermediate portion 8c is substantially rectilinear and of width virtually equal to the width of the grooves 9, 10 of the casing means 2 (Figure 3) .

The length of the channel 8 is such to always enable the flow connection between the lower chamber 4a and the first groove 9 or the second groove 10, regardless of the axial position of the piston means 3. ^■ In the operation of the device 1, the piston means 3 is moved sequentially through four distinct operating conditions, in order to collect a desired amount of liquid from an inlet 12 and direct said desired amount of liquid to the outlet 13. In a first operating position A, at the start of the descending or intake stroke, the piston means 3 is in

^' withdrawn intake position, wherein the channel 8 is arranged aligned is faced to the first groove 9 of the upper chamber

4a and with the operating end 8a faced and virtually coincident with the inlet 12. The further operating end 8b flows out into the lower chamber 4a that is then in flow connection with the intake duct 30.

During the descending stroke of the piston means 3, the fluid to be dosed is withdrawn by vacuum pressure into the lower chamber 4a. The outlet 13 is tight closed by the upper portion 7 of the piston 3. At the end of the descending stroke, in a second operating position B, wherein the piston means 3 is in extended intake position, the lower chamber 4a is fully filled with fluid is and again in flow connection via the longitudinal channel 8 and the first longitudinal groove 9 with the discharge duct 12. Thus, possible air bubbles present inside the space 4a can rise again along the channel 8 and the groove 9 and exit the cavity 4.

The piston means 3 is then rotated in a third operating position C, wherein the channel 8 is aligned with the second groove 10 with Ia operating end 8a thereof faced to said groove 10 and flowing into said groove 10, in order to connect the lower chamber 4a with the discharge duct 31. During the ascending or discharging stroke, the piston means 3 progressively forces the fluid out of the lower chamber 4a towards the discharge duct 31. The inlet 12 is. tight closed by the upper portion 7 of the piston means 3.

At the end of the ascending stroke, the piston means 3 is in a fourth operating position D, i.e. in withdrawn position of discharge. In such fourth operating position D, the channel 8 is arranged faced to the second groove 10 with the operating end 8a thereof arranged faced and virtually coincident with the outlet opening 13. The further operating end 8b flow out in the lower chamber 4a in order to enable, similarly to what is occurring in the first operating position A, possible air bubbles present in the space 4a to flow out.

As known, the air present in a liquid contained inside a cavity aims to rise back vertically for collecting itself in the upper portion of said cavity, as a combined effect of the lower density of the air with respect to the al liquid and the gravity. Since in the first operating position A and in the fourth operating position D of the piston 3 the highest

point of the internal cavity 4 corresponds with the inlet 12 and the outlet 13 respectively, the possible air bubbles present can spontaneously exit from the device 1. The exit of the air is further favored by the vertical movement of the piston means 3 that axially moves in discharge from the third operating position C to the fourth operating position D and in intake from the first operating position to the second operating position B. In a version of the device 1 wherein, the holes of the inlet 12 and the outlet 13 are skew with respect to the side wall of ^' the upper chamber 4b. In particular, the axes of said holes are inclined upwards, starting from the internal surface of the upper chamber 4b, by an angle ranging between 1° and 30°. Thus, the inlet 12 and the outlet 13 and the respective intake duct 30 and discharge duct 31 exhibit a slope directed toward the interior of the space 4 that further facilitates the outflow of possible air bubbles, therein present . The longitudinal channel 8 and Ie grooves 9, 10 exhibit respective bottoms having concave cross section, in particular they consist of portions of cylindrical or ellipsoidal surfaces. Thus, each groove 9, 10 establishes, when faced to the longitudinal channel 8, a substantially cylindrical passage duct of the liquid, of circular or elliptical section (Figure 4) .

Le operating ends 8a, 8b of the channel 8 comprise, for example, portions spherical surfaces or portions of surfaces with double curvature, profiled so as join in accurate and exact manner the longitudinal channel 8 with the openings of inlet 12 and outlet 13.

The shape of the operating ends 8a, 8b, together with the accuracy of positioning of the piston means 3 in the different operating positions, prevent the formation of possible recesses, undercuts, depressions, micro-cavities in which possible air bubbles present in the liquid may adhere and stagnate, mainly during the starting or "turn-on" step of

the device .

This result is also obtained owing to the particularly accurate finish of the surfaces of the casing means 2 and the piston means 3. Thus the geometric micro-imperfections normally present on the surfaces, and appearing generally in shape of scrapes or scratches, of variable shape, depth and direction are so reduced and limited that do not constitute support per the air bubbles to adhere and/or stagnate. Consequently, the device of the invention enables depleting or bleeding of the air to be accomplished in automatic and efficient way, such procedure being to be carried out necessarily before the start of the production. The volume of dosed liquid is defined with precision, being function of the dimensions of the chambers 4a, 4b of the cavity 4, of the portions 6, 7 of the piston means 3 and of the stroke of the piston means 3. Varying said stroke enables the dosing .device 1 to dose defined volumes of liquid contained within a range of values . From the fourth operating position D, the piston means 3 is rotated and brought again in the first operating condition A so as to repeat the dosing cycle.

The casing means 2 and the piston means 3, that are made, for example, in ceramic materials, exhibit reduced values of surface roughness, high wear strength coefficients and a reduced release of particles and are particularly resistant to the high temperatures with very limited coefficients of thermal expansion.

In order to protect the casing means 2 from bursts and shocks that could compromise its integrity and for enabling the device 1 to be assembled with support means of a dosing machine, covering means 15, 16 is provided suitable for covering and containing, in an assembled condition, the casing means 2. The covering means 15, 16 is made of metallic material, typically stainless steel of the type commonly used for the pharmaceutical and/or food applications .

The covering means comprises a lower jacket 15 and an upper jacket 16, removably interconnected via blocking means 17. Said blocking means 17 comprises, for example, a threaded ring nut, suitable for engaging a shoulder 15c of the lower jacket 15 and screwing with a threaded portion 16c of the upper jacket 16.

The lower jacket 15 comprises a first housing 15a configured for containing a lower portion of the casing means 2. Said first housing 15a is upwards open for enabling the casing means 2 to be introduced and exhibits a lower open 15b for the passage of the piston means 3.

The upper jacket 16 comprises a second blind housing 16a, pre-arranged for containing an upper portion of the casing means 2 and, partially, the upper end portion 7 of the piston 3, when this latter lies in withdrawn position.

The upper jacket 16 comprises first connection means 21 and second connection means 22 suitable for connecting respectively the intake duct 30 with the inlet 12 and the discharge duct 31 with the outlet 13. The intake ducts 30 and the discharge ducts 31 comprise adapters of known type, suitable for being connected with rigid and/or flexible ducts and are removably suitable for being coupled with said connection means 21, 22 for example by means of threaded couplings or couplings of the type commonly known as "Tri-clamp".

The external jacket 16 comprises an upper mounting portion 16b suitable for securing the device 1 to support means, for example of a dosing machine with which the device 1 mat be associated. A coupling element 18 is provided also made of stainless steel fixed to the lower end portion 5 of the piston means 3 for enabling this latter to be connected with moving means. With reference to the Figure 5, a version is shown of the displacement dosing device 1 of the invention predisposed for automatic washing and sterilizing processes of the type CIP/SIP, i.e. configured for enabling proper washing and

sterilizing fluids to flow through the internal cavity 4 for washing and sterilizing said internal cavity 4 and the piston means 3.

The casing means 2 and the piston means 3 of such version are identical to those of the device of the embodiment of which at the Figures 1-4.

The covering means 115, 116 comprises a feeding opening 25 and a discharging opening 26 predisposed respectively for the entry and the exit of said washing and/or sterilizing fluids. The feeding opening 25 is ^" obtained on the upper jacket 116 and flow out in the second housing 116a at the bottom of this latter.

The discharging opening 26 is made on the lower jacket 115 at the lower opening 115a. Connecting elements of known type may be attached to the feeding openings 25 and the discharging openings 26, for example of the ^λλ Tri-clamp" type, for connecting the device 1 with tubes and ducts of a washing and sterilizing plant or system. The lower jacket 115 differs from that of the device of Figures 1-4, in that said lower jacket 115 exhibits a greater longitudinal development, because said lower jacket 115 besides the first housing 115a comprises an underlying washing chamber 115d connected with said housing. The washing chamber 115d and Ia lower chamber 4a of the casing means 2 are capable of containing the upper end portion 7, the intermediate portion 6 and, partially, the lower end portion 5 of the piston means 3, in a fifth operating position E for washing said piston means 3. ; The transversal dimensions, i.e. the diameter, of such washing chamber 115d is greater than the diameter of the intermediate portion 6 of the piston means 3 so that the contact of the walls is prevented and a properly dimensioned interspace is . obtained for the passage of washing and sterilizing fluids. Thus, said washing and sterilizing fluids can licks the internal walls of the cavity 4 and the external

walls of the piston means 3 that came into contact with the dosed, liquid, during the execution of a procedure of CIP/SIP type.

In order for the hydraulic tightness between the lower jacket 115 and the piston means 3 to be assured and the out-flowing of fluid and/or vapor to be prevented during the washing/sterilizing step, gasket means 29 is provided. Said gasket means 29 is housed in a respective seat obtained at the lower opening 15b, below the discharging opening 26 and engages in the fifth washing operating position E an end portion 118a of the mounting element 118 that partially covers the lower end portion 5 of the piston 3. Sealing means 27, 28 are interposed between the casing means 2 and the covering means 116, 115 for preventing washing liquids and/or vapors from being able to infiltrate and penetrate in the interspace or space obtained from the external surfaces of the casing means 2 and the covering means 115, 116. With reference to figures 6 and 7, a moving apparatus 40 is further provided suitable for actuating the piston means 3 with translation and rotation movement during the operation of the dosing device 1.

Said moving apparatus 40 is suitable for being associated with a packaging machine or, in a version not shown, with a dosing unit separated from the packaging machine, comprising one or more dosing devices 1.

The moving apparatus 40 comprises first actuating means 41, arranged for translationalIy actuating the piston means 3 and second actuating means 42, suitable for placing in rotation said piston means 3.

In -particular, said actuating means 41, 42 operates on a single connecting shaft 50, one free end 53 of which is removably connected with the mounting element 18, 118 of the piston means 3. The first actuating means 41 comprises first motor means 43 of rotating type, and consisting for example of an electric

brushless motor, connected with, said connecting shaft 50 via first transmission means 44, 45.

Said transmission means is able to convert the rotation movement of the first motor means 43 in a rectilinear translation movement, along a movement direction X virtually- coincident with the longitudinal axis Z of the device 1. Said first transmission means 44, 45 comprises, for example, coupling means of screw-nut type. In particular, the first motor means 43 places in rotation a screw 44 on which a threaded sleeve or female screw 45 engages, prevented from rotating and thus forced to translate along said direction of movement X .

A supporting flange 46 fixed with the sleeve 45 rotationally supports the connecting shaft 50 by means of a respective bearing 47, at the lower end 54 thereof opposed to the free end 53.

The screw 44 is connected with the output shaft of the first motor means 43 by motion reduction means 48, comprising for example a pair of spur gears . Support means 80, 81 is provided fixed to frame of the machine 100 for supporting the full moving apparatus 40. In a version not shown, the first motor means 43 may be of linear type, to directly translationally move the connecting shaft 50. The second actuating means 42 comprises second motor means 49, this also of rotating type and consisting for example in an electric brushless motor, configured for placing in rotation said connecting shaft 50, via second transmission means 51, 52. Said second transmission means 51, 52 comprises sleeve means 51 rotationally fixed with a supporting plate 81 and configured for slidingly engaging a splined portion 52 of the connecting shaft 50. This latter may consists of a splined shaft of known type, for example a splined shaft provided with cylindrical ends 53, 54 for coupling with supporting bearings 47, 59.

The sleeve means 51, these also of known type, enables the shaft 50 to freely translationally slid, with which shaft 50 the sleeve means 51 transmits instead a rotation torque when driven by second motor means 49. The sleeve means 51 is connected with an output shaft of the second motor means 49 by respective motion reduction means comprising, for example, a gear wheel 65 suitable for engaging a cylindrical toothed portion 51a of said sleeve means 51. The moving apparatus 40 is arranged for being inserted and contained inside a containing volume 101, for example of the packaging machine 100, separated with respect to a processing environment 102, wherein for example dosing takes place, by means of a division wall 104. As known, the separation of the environments has to be tight in the case of applications in pharmaceutical and food field, in order to preserve the processing environment 102, maintained in controlled sterile atmosphere, from contamination of any type, for example microbiological, particle, etc.

For that purpose joint means 70 is consequently provided suitable for tight closing a passage opening 105 made on the division wall 104 for the passage of said connecting' shaft 50. The joint means 70 comprises first tube means 56 inserted in the passage opening 105 and fixed with the wall 104, in order to slidingly support the connecting shaft 50. The first tube means 56 has elongate tubular cylindrical shape. Second tube means 57 is interposed between said first tube means 56 and said connecting shaft 50 and is rotationally connected with this latter via respective rolling bearings 59.

The second tube means 57, this also having elongate tubular cylindrical shape, is coaxial with the first tube means 56 and the connecting shaft 50 and may axially slide with respect to this latter, because is free to slide within the

first tube means 56. The rotation of said second tube means 57 is instead prevented by an anti-rotation element 60 that slides within a slot 61 of the first tube means 56. Containing means 55 is provided on the wall 104 to realize the tightness between the first tube means 56 and the opening 105.

Sliding seal 62 are fixed with a first end of the first tube 56 for engaging the external cylindrical surface of the second tube 57 and realizing so the tightness. The joint means 70 further comprises a connecting element 63 suitable for connecting the free end 53 of the connecting shaft 50 with the coupling element 18 of the piston means 3. A' rotating seal 64 is provided, fixed to said connecting element 63 for engaging the external cylindrical surface of the second tube 57.

The seals 62, 64 assure Ia separation between the containing volume 101 and the processing environment 102. The moving means 40 may comprise a plurality of actuating means 41 and 42, for driving respective dosing devices 1, as shown in Figure 7. Each dosing device 1 is thus operated by respective first motor means 43 and second motor means 49 in independent manner.

Alternatively, there is provided that the second motor means 49 comprises only one motor capable of actuating the totality of the dosing devices 1. In that case, the second actuating means 42 comprises respective coupling/releasing means configured for connecting or disconnecting respective second transmission means 51, 52 from, said motor 49, in the . case that the corresponding dosing device 1 is respectively to be actuated or blocked.

It is important to note that the moving apparatus 40 of the invention is fully accommodated inside the containing volume 101 of the packaging machine, which containing volume 101 is hermetically separated from the processing environment 102 and suitable for being accessed in independent and distinct manner, for example via lateral panels. Thus, it is possible

to lightly and rapidly intervene on mechanical members and components of the apparatus 40, for example for servicing and/or repairing operations, without having to transit through said environment 102, compromising the sterility of said environment 102.

With particular reference to figures 6 and 7, it is noted that the moving apparatus 40 is arranged below the dosing devices, so as to actuate from below the piston means 3 of the device 1. Thus, in the case that the processing environment 102 is subjected to an unidirectional, vertical air flow, the apparatus 40 does not perturb such air flow, at an overhanging operating region, wherein dosing takes place. On the upper portion of the device 1, in fact, the presence of any moving member is not necessary. Since also the connection between the piston means 3 and the actuating means 41, 42 is positioned below the operating region, possible particles or contaminants that may be generated by the movements of- translation and rotation of the piston means 3 are dragged downwards by the air flow, without being capable of rising again and involve said operating region.

No particular restriction exists in positioning of the dosing device or the devices of the invention within a dosing machine. Such devices and relative moving means, since do not perturb, or perturb very scarcely, said unidirectional air flow, can be arranged also near the operating region, in order to realize for example a machine of reduced transversal dimensions, enabling all the operating groups to be easily accessed from a. single frontal or rear side. The dosing device 1 and the relative moving apparatus 40 result consequently particularly suitable for being associated with a dosing packaging machine, operating in aseptic and/or sterile atmosphere under unidirectional and uniform air flow, for example a machine placed within a sterile space or a machine provided with a sealing cabin or insulator.