WEIGHING APPARATUS AND METHOD FOR A FILLING LINE FOR FILLING CONTAINERS OF PHARMACEUTICAL, MEDICAL, FOOD PRODUCTS OR SIMILAR TECHNICAL FIELD

Embodiments described herein relate to an apparatus and method for weighing containers having various forms, for example vials, ampoules, bottles, capsules, containing various substances, for example liquids, which are more or less viscous, powders, granules, in particular in the pharmaceutical, medical or food sector, where there is a great need for weighing precision, accuracy and repeatability.

BACKGROUND ART

It is known that an industrial line for filling containers in the pharmaceutical, medical or food sector may comprise, in addition to a filling operating station, a weighing apparatus for checking the quantity inserted in the containers. That applies in particular in the pharmaceutical or medical sector, in which the quantities of product that are inserted in the containers must be weighed with extreme precision, with a tolerance of approximately a microgram. For example, incorrect weighing of a medicine may result in serious risks for the health of a patient.

It is also known that in an industrial line of the type discussed, filling and weighing operations must be performed in an essentially sterile internal environment, protected, with a controlled atmosphere, as far as possible free of elements that may pollute or contaminate the substance in the containers. For that purpose, in addition to protecting the line perimeter using screens or walls that contain it, and supplying a sterile air filtering system, there is a known practice of generating a laminar air flow forced from the top down, which strikes the line components and exits, thanks to the pressure difference between the inside environment and the outside environment, through lower or side peripheral slits, drawing with it dust, dirt, micro-particles or any other kind of air macro- or micro-pollutants.

Amongst the weighing systems discussed, with the above-mentioned precision requirements, it is also known that factors outside of the weighing operation may affect its precision and repeatability, for example the air surrounding the weighing apparatus, its density, its pressure or local speed. Therefore, as well as monitoring and subsequently eliminating, or reducing, via software, any intrinsic errors attributable to the weighing units, it is also necessary to consider variations due to environmental factors. In particular, it has been found that the above-mentioned from the top down laminar air flow may generate a weight measurement error in the weighing apparatus. For example, micro-vortices or local turbulences may be generated which may invalidate the measurement. Such a measurement error can be compensated via software; however, since it is not a constant and repeatable error, due to differing conditions of local laminar flow interference with the line components, even that electronic compensation may not be sufficient.

Therefore, it is necessary to improve a weighing apparatus and method for a filling line for filling containers of pharmaceutical, medical, food products or similar which can overcome at least one of the disadvantages of the prior art.

To overcome the disadvantages of the prior art and to achieve these and further aims and advantages, the Applicant has devised, tested and produced this invention.

DISCLOSURE OF THE INVENTION

This invention is described and characterised in the independent claims, whilst the dependent claims describe other features of this invention or variants of the main solution idea.

In accordance with this invention, a weighing apparatus is provided for a filling line for filling containers of pharmaceutical, medical, food products or similar, which comprises at least one weighing unit and at least one suction unit designed to generate a sucked air flow directed in such a way that it affects the weighing unit.

According to a possible embodiment, the above-mentioned apparatus comprises a covering and protecting structure which contains and protects said at least one weighing unit and said at least one suction unit and a laminar flow generating unit designed to generate a laminar air flow in said covering and protecting structure. According to a variant of that embodiment, said suction unit and said laminar flow generating unit are designed to cause the interaction of said sucked air flow and said laminar air flow at least at said at least one weighing unit.

This invention also relates to a filling line for filling containers which comprises a weighing apparatus in accordance with this description, a container filling apparatus and a container closing apparatus. According to this invention, at least said weighing apparatus is protected by a covering and protecting structure and a laminar flow generating unit is provided for generating a laminar air flow in said covering and protecting structure.

This invention also relates to a weighing method for a filling line for filling containers of pharmaceutical, medical, food products or similar. Said method comprises:

- weighing containers using one or more weighing units each equipped with one or more weighing devices;

- generating a sucked air flow directed in such a way as to affect said one or more weighing units.

According to possible embodiments, said method comprises weighing containers in a covering and protecting structure that contains and protects said one or more weighing units, and generating a laminar air flow in said covering and protecting structure. According to such embodiments, said sucked air flow and said laminar air flow interact at least at said at least one weighing unit.

According to a variant of said embodiments, the method comprises processing, even depending on an expected measurement error due to said sucked air flow, a signal indicating the weight detected during weighing of the containers.

In accordance with a further variant, the weighing method comprises a preliminary step of weighing setup in the presence of said sucked air flow and in the absence of containers in the one or more weighing units, in which the sucked air flow is adjusted until all of the weighing devices supply the same weight measurement value.

This invention also relates to a method for filling containers of pharmaceutical, medical, food products or similar. Said method comprises:

- filling the containers;

- weighing containers using one or more weighing units each equipped with one or more weighing devices;

- generating a sucked air flow in relation to the containers at least during weighing of the containers;

- closing the containers.

The expression "sucked air flow in relation to the containers" means, for example and without limiting the scope of the invention, a sucked air flow that passes near to the container weighing unit or units, or even strikes them directly, and which affects the weight value detected by the weighing unit or units.

According to this description, said filling method provides that at least the weighing of the containers is carried out in a covering and protecting structure that contains and protects said one or more weighing units and, moreover, that a laminar air flow is generated at least in said covering and protecting structure, and that said sucked air flow and said laminar air flow interact at least at said one or more weighing units.

These and other aspects, features and advantages of this disclosure will be better understood with reference to the following description, to the drawings and to the appended claims. The drawings, which are integrated with and form part of this description, illustrate some embodiments of the present subject matter and, together with the description, intend to describe the principles of the disclosure.

The various aspects and features described in this description may be applied individually, where possible. These individual aspects, for example aspects and features in the description or in the appended dependent claims, may form the subject matter of divisional applications.

It should be noticed that any aspect or feature found to be already known during the patenting procedure shall be understood to be not claimed and to be the subject of a disclaimer.

DESCRIPTION OF THE DRAWINGS

These and other features of this invention will appear clear from the following description of embodiments, given by way of non-limiting example, with reference to the appended drawings, in which:

Figure 1 is a schematic top plan view of a weighing apparatus according to embodiments described herein;

Figure 2 is a schematic front view of a weighing apparatus according to embodiments described herein;

Figure 2a is a schematic front view of a weighing apparatus according to further embodiments described herein;

Figure 2b is a schematic front view of a weighing apparatus according to further embodiments described herein;

Figure 3 is a schematic top plan view of a weighing apparatus according to further embodiments described herein;

Figure 4 is a schematic front view of a weighing apparatus according to further embodiments described herein;

Figure 5 is a schematic top plan view of a weighing apparatus according to further embodiments described herein;

Figure 6 is a schematic front view of a weighing apparatus according to still further embodiments described herein; Figure 7 is a schematic top plan view of a weighing apparatus according to further embodiments described herein;

Figure 8 is a schematic front view of a weighing apparatus according to further embodiments described herein;

Figure 9 is a front view in cross-section of part of a weighing apparatus according to still further embodiments described herein;

Figure 10 is a perspective view partly in cross-section of a weighing apparatus according to further embodiments described herein;

Figure 11 is a schematic top plan view of a weighing apparatus according to further embodiments described herein;

Figure 12 is a schematic top plan view of embodiments of a filling line for filling containers comprising a weighing apparatus according to embodiments described herein; Figure 13 is a schematic top plan view of further embodiments of a filling line for filling containers comprising a weighing apparatus according to embodiments described herein. For easier understanding, identical reference numerals have been used, where possible, to identify identical common elements in the figures. It shall be understood that elements and characteristics of one variant may be appropriately incorporated in other variants without further clarification.

DESCRIPTION OF EMBODIMENTS

Reference will now be made in detail to the various embodiments of the invention, of which one or more examples are illustrated in the appended figures. Each example is given in order to illustrate the invention, and it is not to be understood as a limitation of the invention. For example, the features illustrated or described because they are part of one variant may be adopted on, or in association with, other embodiments. It shall be understood that this invention will include such modifications and variants.

Embodiments described herein relates to a weighing apparatus 10 for a filling line 70 for filling containers 12 of pharmaceutical, medical, food products or similar.

According to embodiments described using Figures 1 and 2, and combinable with other embodiments described herein, the apparatus 10 comprises at least one container weighing unit 20 and at least one suction unit 14 designed to generate a sucked air flow directed in such a way as to affect the container weighing unit 20. In the accompanying figures, the sucked air flow is schematically indicated, where possible, by the dashed line arrows S. The sucked air flow is directed, for example and without limiting the scope of the invention, near to the container weighing unit 20, and/or containers 12 subject to weighing, in such a way as to generate a local perturbation capable of affecting the weighing unit 20 in a controllable way, that is to say, of affecting in a controllable way the weight value detected by the weighing unit 20. It is possible to provide that the sucked air flow and/or of the suction unit 14 is positioned lateral, angled or underneath, or a combination of said positions.

Further embodiments described herein relate to a weighing method for a filling line 70 for filling containers of pharmaceutical, medical, food products or similar.

In accordance with this description, the method comprises:

- weighing the containers 12 using one or more weighing units 20;

- generating a sucked air flow directed in such a way as to affect said one or more weighing units in a controllable way, at least during weighing of the containers 12.

According to embodiments described using Figures 3 and 4, and combinable with other embodiments described herein, the apparatus 10 also comprises a container advancing device 16. Therefore, in accordance with further embodiments described herein, the method may also comprise advancing the containers.

In possible embodiments, combinable with all of the embodiments described herein, the container advancing device 16 is designed to cause at least one row of containers 12 to advance, conveying them along an advancing direction F. Examples of a container advancing device 16 usable in the embodiments described herein may be a conveying device, in particular a closed loop belt conveyor, a closed loop band conveyor belt, a supporting surface, or table, movable by means of a linear motor, a band or belt for conveying inside a filling line 70 for filling pharmaceutical, medical or food containers. An actuating element may be provided for driving the container advancing device 16. The actuating element may comprise a driving unit designed to move the containers, which is made to operate by an energy source, for example electric current, hydraulic fluid pressure or pneumatic pressure. A driving unit like that used in association with the embodiments described herein may be a driving unit selected in a group comprising: an electric motor, an electric stepper motor, a magnetic motor, a linear axis with a motor, a linear motor, such as a mechanical linear motor, a piezoelectric linear motor, an electromagnetic linear motor, an electromechanical motor, an electromagnet, a gear motor, in particular a direct current gear motor. For example, motors which use electromagnetism and magnetic fields for interaction between a first part consisting of electric windings and a second part consisting of other electric windings, or of permanent or energised magnets, or of a conductor may be provided. In specific possible exemplary embodiments, the driving unit may be designed like a linear motor, for example a linear induction motor, a synchronous linear motor, a brushless synchronous linear motor, a homopolar linear motor, a voice coil linear motor, a tubular linear motor, or even, as indicated, a piezoelectric linear motor or an electromagnet. The actuating element may be made to operate to cause advancing and pause steps of the container advancing device 16. For example, a pause step may be provided for transferring containers 12 from the container advancing device 16 to the weighing unit 20.

In possible further embodiments described using Figures 2, 4, 6 and 8, combinable with all of the embodiments described herein, the container weighing unit 20 may comprise a container support 42 and a sensor unit 24 designed to detect a weight acting on the container support 42.

For example, and without limiting the scope of any of the embodiments, a container support 42 of the type used in the embodiments described herein may be a flat plate, a supporting disk, a small plate, a portion of the container advancing device, a container- holder, a pedestal or other support suitable for supporting the container 12.

In some embodiments given by way of non-limiting example, the sensor unit 24 may comprise one or more sensors for detecting the weight.

It should be noticed that one or more of the sensors included in the sensor unit 24 as used in the embodiments described herein may be at least one sensor element selected from the group comprising:

- a force sensor or transducer, such as a load cell, for example a load cell with strain gauge, a hydraulic or hydrostatic load cell, a piezoelectric load cell, a vibrating wire load cell and a capacitive load cell;

- a pressure sensor or transducer, for example of the electronic type generally used for collecting a force for measuring deformation or deviation caused by the force applied on an area, such as a sensor with piezo-resistive strain gauge, a capacitive sensor, an electromagnetic sensor, a piezoelectric sensor, an optical sensor or a potentiometric sensor. It shall be understood that depending on the specific position of the sensor unit 24, the sensor unit may even comprise at least one pressure sensor and at least one force sensor, for example a load cell.

According to different implementations of the embodiments described herein, the weight on the container support 42 may be detected by one or more load cells, one or more pressure sensors or one or more other sensors, which use a strain gauge, a piezoelectric element, a piezo-resistive element, a Hall effect element, or the like. In this context, it must be considered that a pressure is the force applied per surface unit, so that depending whether one or more sensors are used such as pressure sensors or as force sensors or load cells, a conversion may have to be considered.

In accordance with possible implementations, the sensor unit 24 is independent of what applies the pressure or force. For example, the sensor does not activate, move or affect the container 12, the container support 42, or any other part or portion of the apparatus 10.

In embodiments described using Figures 1, 2, 2a, 2b, 3 and 4, the apparatus 10 may comprise one or more suction units 14 positioned near a single weighing unit 20.

In embodiments described using Figures 2, 2a, 2b, 5, 6, 9 and 10, the apparatus 10 may comprise one or more suction units 14 positioned near two weighing unit 20.

In some embodiments described herein with reference to Figures 3, 4, 5 e 6, a weighing unit 20 may be positioned in an intermediate position between the container advancing device 16 and the suction unit 14. In other words, the suction unit 14 may be positioned in a position further outside the weighing unit 20, relative to the container advancing device 16.

In other variants, a suction unit 14 may be positioned between the weighing unit 20 and the container advancing device 16.

In yet other variants, a weighing unit 20 may be positioned between two suction units 14

(see, for example, Figure 2a).

Further variants, may provide for a suction unit 14 positioned underneath a respective weighing unit 20 (see, for example, Figure 2b).

It is evident that the possible embodiments also include the possible combinations of the mutual positions described herein of one or more weighing units 20, one or more suction units 14 and the container advancing device 16.

It is also clear that the embodiments described using Figures 2, 2a and 2b may be used in combination with the embodiments described using Figures 1, 3 and 4, or with the embodiments described using Figures 5, 6, 9 and 10.

In possible further embodiments, combinable with all of the embodiments described herein, the suction unit 14 may comprise one or more suction members 52, 54. A suction member usable in the embodiments described herein may comprise a suction pump driven by a driving unit. The driving unit may be an electric motor. In other variants, the suction member may be a Venturi effect suction member.

The suction unit 14, in particular the suction pump, or the Venturi effect suction member, may be connected to a suction duct 55 comprising a suction mouth 58, which may be positioned facing towards the containers 12 near the weighing unit 20, for generating the desired sucked air flow shown by the dashed line arrows S.

Advantageously, the suction mouth 58 may be positioned below the container support

42.

The suction member may be equipped with one or more adjusting valves 62 for adjusting the suction flow, which allow control of the effect of the air flow on each weighing unit 20, that is to say, on the weight value detected by the respective sensor unit 24 of each weighing unit 20.

Basically, the suction unit 14, in particular the suction member, may be provided with one or more adjusting valves 62 designed for adjusting the sucked air flow exiting through the suction mouth 58.

Figures 3 and 4 are used to describe further embodiments, combinable with all of the embodiments described herein, of the apparatus 10 according to this description, which may comprise a single weighing unit 20 positioned at the side of the container advancing device 16 and in which the suction unit 14 comprises a single suction member 52, or 54, positioned close to the single weighing unit 20. For example, what may be used also for other embodiments described herein, the single suction member 52, 54 may be positioned aligned at the side of the weighing unit 20, or in a lateral and lower position relative to it (see, for example, Figure 4).

Figures 5 and 6 are used to describe further embodiments, combinable with all of the embodiments described herein, of the apparatus 10 according to this description, which may comprise two weighing units 20 positioned on opposite sides of the container advancing device 16, on one side and on the other side with respect to the advancing direction F and two suction members 52, 54 positioned close to a respective weighing unit 20.

According to further embodiments described herein using Figures 7 and 8, and combinable with other embodiments described herein, the apparatus 10 may also comprise a container transferring device 46, designed to transfer the containers 12 from the container advancing device 16 to the weighing unit 20 and vice versa, along a transferring direction T. Therefore, in accordance with further embodiments described herein, the method may also comprise a transfer of the containers from the advancing direction F to a weighing zone. The weighing zone is where the weighing unit 20 is positioned. For example, said weighing zone may be at a side of the container advancing device 16. The transferring direction T may, therefore, be transversal, for example orthogonal, to the above-mentioned advancing direction F.

It is also clear that the embodiments described using Figures 7, 8 may be used in combination with the embodiments described using Figures 1 , 2, 2a, 2b, 3 and 4, or with the embodiments described using Figures 5, 6, 9 and 10.

According to embodiments described using Figures 9 and 10, and combinable with the embodiments of Figures 7 and 8, the container transferring device 46 may comprise one or more transferring members, or arms 48 which are selectively movable. In accordance with this invention, Figures 9 and 10 are used to describe further embodiments, combinable with all of the embodiments described herein, of the weighing apparatus 10 discussed, which may be included in a filling line 70 that comprises a container filling apparatus 64 and a container closing apparatus 66 (see, for example, Figures 12 and 13). In accordance with the embodiments described herein, in the weighing unit 20 weight checks may be carried out on 100% of the containers 12, or on a sample number of containers 12, based on any statistical analysis application. For example, the containers 12, after having been filled by the container filling apparatus 64, are conveyed by the container advancing device 16 to the weighing unit 20.

In possible implementations, a weighing unit 20 usable in the embodiments described herein comprises one or more weighing devices, or scales, 22 each of which is provided for checking the weight of a specific container 12.

Each weighing device 22 comprises the above-mentioned container support 42, a sustaining rod 40 suitable for sustaining the container support 42 and the above-mentioned sensor unit 24. The sensor unit 24 may be dedicated to each weighing device 22, or it may be shared between coordinated pairs of weighing devices 22, for example which are positioned aligned on one side and the other side of the container advancing device 16, transversally to the advancing direction F (see, for example, Figure 6). Therefore, the sensor unit 24 may serve both a weighing device 22 of a weighing unit 20 on one side of the container advancing device 16 and a homologous and aligned other weighing device 22 of the other weighing unit 20 positioned on the opposite side. In contrast, within the same weighing unit 20, each weighing device 22 is served by its own sensor unit 24, that is to say, there is no sharing of a sensor unit 24 between weighing devices 22 belonging to the same weighing unit 20.

For example, in the embodiments in which there are two weighing devices 22 belonging one to a weighing unit 20 and one to another weighing unit 20, positioned aligned on one side and the other side of the container advancing device 16, transversally to the advancing direction F, there is a supporting element 26, positioned transversally to the advancing direction F of the container advancing device 16, which supports the sustaining element 40 and the container support 42 (see, for example, Figure 6).

The supporting element 26 has an axis of symmetry M and the respective sustaining elements 40 and container support 42 are located in positions symmetrical with respect to said axis of symmetry M. Said axis of symmetry M may advantageously be located at the longitudinal centre line of the container advancing device 16, that is to say, at the advancing direction F.

As shown, for example, in Figures 1, 3, 5 and 6, in possible embodiments, each weighing unit 20 may therefore be equipped with respective rows of weighing devices 22. Therefore, overall, there are opposite rows of weighing devices 22, on one side and the other side of the container advancing device 16, positioned between the above-mentioned suction members 52, 54.

The weighing apparatus 10 also comprises a supporting structure 30 (see, for example, Figures 9 and 10).

Fixing pins 28 are used for fixing, in particular on one side and the other side of the above-mentioned axis of symmetry M, the horizontal supporting element 26 to a supporting element 31, for example a longitudinal supporting bar, of the supporting structure 30.

In possible variants, the supporting structure 30 is designed to reduce and if necessary neutralise possible vibrations that could invalidate weighing.

In accordance with further possible embodiments, the weighing unit 20 may comprise a covering element, or protective guard, 44 (see, for example, Figures 9 and 10) suitable for protecting the weighing devices 22, leaving uncovered and accessible only the container supports 42, thereby protecting against any dust particles or foreign bodies, or even against the substance to be inserted in the vial, which may significantly affect the weight detected.

In accordance with further possible embodiments, the covering element 44 comprises lateral walls 56, for example angled downwards with respect to the container supports 42 in such a way as to guide the sucked air flow indicated by the dashed line arrows S.

In particular, for that purpose, the first suction member 52 and the second suction member 54 are positioned in contact on the lateral walls 56, in such a way that the respective suction mouths 58 are facing towards the container supports 42, or at a zone below them towards the sustaining element 40.

Advantageously, the suction mouth 58 of each suction member 52, 54 extends along the entire length of the row of container supports 42 belonging to a respective weighing unit 20. Therefore, each container support 42 is subject to the sucked air flow, which affects the respective weighing device 22 in a controllable way.

In accordance with embodiments, the suction mouth 58 may be divided into two or more suction sectors, each of which is suitable for generate a respective sucked air flow, which may be associated with a respective container support 42, in such a way that each container support 42 is subject to a respective sucked air flow, which affects the respective weighing device 22. Each suction sector may comprise its own suction nozzle 60.

In accordance with further embodiments, the sucked air flow is selectively controllable using the above-mentioned adjusting valves 62, in such a way as to create a sucked air flow that affects all the container supports 42 included in the weighing device 22. Each suction nozzle 60 may be connected to its own adjusting valve 62, in such a way as to adjust the sucked air flow affecting each container support 42 independently of the sucked air flows affecting the other container supports 42. In this way, it is possible to adjust the sucked air flows in such a way that each weighing device 22 is affected by the respective sucked air flow differently and independently of the other weighing devices 22.

Figure 11 is used to describe further possible embodiments, combinable with the embodiments previously described, in which the weighing apparatus 10 comprises a covering and protecting structure 63, which contains and protects the one or more weighing units 20 and the respective one or more suction units 14, and the container advancing device 16 and container transferring device 46 if any.

In this way, advantageously, the weighing apparatus 10 may be isolated from the outside environment, so as to obtain a controlled atmosphere. The covering and protecting structure 63 may be made using a suitable protective material, for example glass, polymer, metal or any other suitable material.

The weighing apparatus 10 may also comprise a laminar flow generating unit 50 designed for generating a controlled laminar air flow L inside the covering and protecting structure 63, which usually travels from the top down, exploiting the pressure difference between the inside environment and the outside environment (see, for example, Figure 11).

Therefore, according to this description, the laminar air flow generated by the laminar flow generating unit 50 strikes from the top down the one or more weighing units 20, in particular the surface of the container supports 42, whether they are empty or occupied by a container 12.

That flow allows the creation of a controlled atmosphere in the covering and protecting structure associated with the weighing apparatus 10. However, as discussed above, it may also generate unwanted local micro-turbulences close to the one or more weighing units 20, and therefore measurement errors which may be unforeseeable.

Basically, the one or more weighing units 20 disturb the air flow L, in particular they upset the laminar nature of the air flow L, to the extent that at the weighing units 20 turbulences and/or vortices are generated which are such as to affect negatively, and in an unrepeatable way, the measurement values of the weight of the containers 16. The turbulences and/or vortices may, for example, act negatively on the container supports 42.

The apparatus 10 and method according to this description overcome said disadvantage thanks to the generation of the above-mentioned sucked air flow locally at the one or more weighing units 20. The sucked air flow generates a local perturbation whose extent is known and repeatable. It does not matter if the turbulences and/or vortices caused by the sucked air flow generate a systematic measurement error whose absolute value is greater than or less than the measurement error that would occur in the absence of the sucked air flow. What does matter is that the sucked air flow, together with the laminar air flow L, generates a highly repeatable error and therefore an error that can substantially be eliminated, for example using software.

Advantageously, it is possible to generate a sucked air flow such as to reduce, or even cancel out, the turbulences and/or vortices present at, and caused by, the container supports 42, so as to restore the laminar air flow L, even at the container supports 42.

Advantageously, the above-mentioned suction unit 14 and the above-mentioned laminar flow generating unit 50 are designed to cause said sucked air flow and said laminar air flow interact at least at the one or more weighing units 20.

It is, therefore, believed that the effect caused locally by the laminar air flow L, combined with the sucked air flow, generates a perturbation on the weighing unit, in particular on the container support 42, which introduces an error that may be predefined and is repeatable, and as such, manageable, that is to say eliminable, for example using software, with repeatability and reliability, whatever the absolute value of that error is. For that purpose, there is a control unit, or system controller 25, which receives a weight signal detected by each sensor unit 24. Said control unit 25 is designed to process, using software, the signal received, even depending on the expected measurement error due to the above- mentioned sucked air flow. It was found that in this way, overall, detection of the weight of filled containers 12 is more reliable, that is to say, more precise and accurate.

In embodiments, the method described herein may comprise a weighing setup preliminary step in the presence of the sucked air flow and in the absence of containers 12 in the one or more weighing units 20. That is to say, a no-load weighing setup preliminary step is performed on the weighing devices 22, adjusting the sucked air flow until all of the weighing devices 22 "with no load" supply the same weight measurement value. In detail, in the absence of containers 12, the amount of the sucked air flow is controlled, in particular adjusting the adjusting valves 62, so that all the weighing devices 22 present give the same weight measurement in the presence of the desired sucked air flow. Therefore, by means of the weighing setup preliminary step, the generation and control of suction is carried out in such a way that, in the absence of containers 12 in the weighing units 20, all the weighing devices 22 give identical weight measurements. Such weight measurements, with "no load" and in the presence of the sucked air flow, are used as a reference for all the measuring devices 22. In possible implementations, the weight value given by the weighing devices 22, in the absence of containers 12 and in the presence of the sucked air flow, is managed using software in the measurement of the weight of the containers 12 by the above-mentioned control unit 25, in particular, for example, by subtracting it from the weight measurement performed on the containers 12.

Advantageously, the method according to the invention may comprise the weighing setup preliminary step in the presence of the laminar air flow L and the sucked air flow, and in the absence of containers 12 in the one or more weighing units 20.

Said weighing setup preliminary step may be simultaneous with, or subsequent to, the start of generation of the sucked air flow and in any case precedes weighing of the containers 12, in particular preceding the positioning of the containers 12 to be weighed on the respective container supports 42. For example, in variants of the method according to this description, initially the sucked air flow is generated in the absence of containers 12 in the one or more weighing units 20, then the weighing setup preliminary step is performed in the absence of the containers 12, adjusting the sucked air flow generated, followed by weighing of the containers 12 maintaining, during the weighing, the sucked air flow generated and already adjusted during the weighing setup preliminary step.

In possible embodiments of the method according to this description, to take into account possible effects on the container supports 42 "with no load", that is to say, when they are not occupied by containers 12, due to the sucked air flow which, in a desired way, locally disturbs the system, the weighing setup preliminary step may comprise essentially zeroing the one or more weighing units 20, before they are occupied by the containers 12 to be weighed, that is to say, when the container supports 42 are still empty. The term "zeroing" means that the weight value measured "with no load" by the one or more weighing units 20, in particular by the one or more sensor units 24, is advantageously set, by means of the above-mentioned control unit 25, equal to zero, subject to the tolerances linked to the precision of the instrument.

This zeroing step allows the setting of a condition of zero weight detected by the one or more sensor units 24 relating to a condition in which the sucked air flow is present. In other words, all of the sensor units 24 are set to a reference "zero" condition which takes into account the effects of the sucked air flow on the empty container supports 42, that is to say, not occupied by the containers 12. Therefore, in this variant, essentially the common weight value that the weighing devices 22 give following the weighing setup preliminary step, in which the sucked air flow is suitably adjusted, is equal to zero. The control unit, or system controller 25 may comprise a central processing unit, or CPU, an electronic memory, an electronic database and auxiliary circuits (or I/O) (not illustrated). For example, the CPU may be any type of computer processor usable in the computer science sector for automation and control. The memory may be connected to the CPU and may be one or more of those commercially available, such as a random access memory (RAM), a read only memory (ROM), a floppy disk, a hard drive, a mass storage device, or any other type of digital, local or remote storage. The software instructions and the data may, for example, be coded and saved in the memory for controlling the CPU. Even the auxiliary circuits may be connected to the CPU, for helping the processor in a conventional way. The auxiliary circuits may comprise, for example, at least one of the following: cache circuits, power circuits, clock circuits, input/output circuitry, sub-systems, and the like. A program (or computer instructions) that can be read by the control unit 25 can determine which tasks can be performed in accordance with the method according to this description. In some embodiments, the program is software that can be read by the control unit 25. The control unit 25 comprises a code for generating and saving information and data entered or generated during the method according to this description.

Figures 12 and 13 are used to describe embodiments of a filling line 70 which may comprise a weighing apparatus 10 according to this description.

In particular, the filling line 70 may comprise a container filling apparatus 64, the weighing apparatus 10 and a container 12 closing apparatus 66. The above-mentioned container advancing device 16 may be designed to serve sequentially the container filling apparatus 64, the weighing apparatus 10 and the container closing apparatus 66 along the advancing direction F.

In the embodiments of the filling line 70 described using Figure 12, dedicated covering and protecting structures for each line component are provided. In particular, the container filling apparatus 64 and the container closing apparatus 66 are protected by respective covering and protecting structures 65, 67, just as the weighing apparatus 10 is protected by the above-mentioned covering and protecting structure 63 described using Figure 11. Advantageously, the transit of the containers 12 from one to the other of the apparatuses 64, 10 and 66 may be performed using protected conveying and transporting systems. Moreover, even each of the covering and protecting structures 65, 67 may be associated with a respective laminar flow generating unit 50, with operation similar to what has been described above.

In the embodiments of the filling line 70 described using Figure 13, there is a single covering and protecting structure 69 for the entire line, that is to say, which contains and protects the container filling apparatus 64, the weighing apparatus 10 and the container closing apparatus 66. In that case, a single laminar flow generating unit 50 may be provided.

It is evident that the weighing apparatus 10 and method described above may be subject to changes and/or additions to parts and/or steps without thereby departing from the scope of the present invention.

It is also evident that, although this invention has been described with reference to some specific examples, a skilled person will certainly be able to produce many other equivalent forms of the weighing apparatus, having the features indicated in the claims and therefore all covered by the limits of protection defined by them.

Although what has been described above refers to embodiments of the invention, other and further embodiments are possible, without thereby departing from its main limits of protection, and the related scope of protection is defined by the following claims.