DK2821149T3

DK2821149T3 - APPLIANCE AND SYSTEM FOR EXTERNAL CLEANING OF LIQUID CONTAINERS

Info

Publication number: DK2821149T3
Application number: DK13175003.6T
Authority: DK
Inventors: Luigi Sacchi; Massimiliano Sacchi
Original assignee: F Lli Sacchi Di Sacchi Angelo E C S N C
Priority date: 2013-07-04
Filing date: 2013-07-04
Publication date: 2018-01-08
Also published as: ES2667423T3; EP2821149B1; NO2821149T3; PL2821149T3; EP2821149A1

Description

DESCRIPTION

BACKGROUND OF THE INVENTION

[0001] The present invention refers to an apparatus and a cleaning system that are suitable for removing dirt or polluting substances that have adhered to the external surface of containers, in particular containers for loose substances, intended for automatic opening and emptying plants.

[0002] For the purposes of the present description, the term "container" is defined as any type of bag, box, stiff or flexible package made of paper, cardboard, fabric, plastics or a combination thereof Further, the loose substance inside the containers can be of any type; for example, it can consist of powder, granular, liquid or pasty substances. Lastly, the containers can be cleaned by spraying any type of liquid, gas or powder fluid, for example, air, water, sterilising gas or liquids, disinfecting gas or liquids, fluidising powders in general, or combinations thereof, in function of the type of container, of the material with which the container has been made, and/or of the loose substance contained therein.

[0003] The apparatus and the cleaning system according to the invention lend themselves to applied to any technological field, for example to the food, chemical, industrial sector, i.e. in all those cases in which the containers, before being automatically emptied, have to be washed or cleaned to ensure suitable conditions for avoiding that dirt or polluting substances that have adhered to the external surface of the containers during conveying and/or storing thereof, can become mixed, during automatic opening of the containers, with the substance contained therein, and contaminate said substance.

PRIOR ART

[0004] As already mentioned, containers for loose substances, such as bags, boxes or the like, before being automatically opened and emptied, have to be suitably washed and/or cleaned to avoid dirt or extraneous substances, which have adhered to the external surface of the containers, during opening and emptying can pollute the substance or the product contained therein, or be dispersed towards the external environment.

[0005] Currently, for cleaning containers, in general, a manual procedure is followed, using brushes, jets of pressurised water or air on each single container, before opening.

[0006] Cleaning containers manually, in addition to requiring much time, does not ensure a thorough degree of hygiene and cleaning, and an appropriate protection of the external environment, negatively affecting the work cycle and the automatic opening systems.

[0007] Using simple conveyors provided with spray nozzles, would not in itself solve the problem of automation avoiding recontamination of the containers and dispersal of contaminating substances in the external environment.

[0008] Further, the tendency today to increase the productivity of automatic plants for opening containers requires automatic cleaning solutions and devices that are extremely versatile that are able to meet the most diverse needs.

[0009] US 2007/056612A1 discloses a tunnel washer, particularly for cleaning articles used in the care of laboratory animals, that includes fluid exhaust paths and spaced-apart double wall curtains for isolating chambers of the tunnel; the tunnel washer also includes an air manifold for uniformly drying the articles.

[0010] DE 4332857A1 discloses a semiconductor cleaning apparatus which includes a cleaning portion for cleaning a wafer, a wafer cleaning portion for cleaning with water the cleaned wafer and a drying portion for drying the wafer cleaned with water.

OBJECTS OF THE INVENTION

[0011] One object of the present invention is thus to provide an apparatus that is suitable for the external cleaning of containers for loose substances, which requires a high degree of automation, minimising, if not wholly eliminating any risk of contamination of the environment and of the product during opening and emptying of the containers.

[0012] A further object of the invention is to provide a system suitable for external cleaning of containers, that is extremely versatile and is able to permit a high degree of productivity.

[0013] Another object of the invention is to provide a system for external cleaning of containers, as previously mentioned, which enables successive cleaning steps to be executed using the same cleaning fluid, or using different cleaning fluids, depending on the features of the containers to be cleaned and on the nature of the loose substance contained therein.

SHORT DESCRIPTION OF THE INVENTION

[0014] The objects referred to above are achievable with an apparatus suitable for the external cleaning of containers for loose substances, according to claim 1, respectively with a system according to claim 7.

SHORT DESCRIPTION OF THE DRAWINGS

[0015] The apparatus and the system for the external cleaning of containers, according to the present invention, will be explained in greater detail here below, with reference to the attached drawings, in which:

Fig. 1 shows schematically a plan view of the cleaning apparatus;

Fig. 2 is a longitudinal section according to the line 2-2 of figure 1, in combination with an automatic robot for removing and transferring the containers;

Fig. 3 shows a dual cleaning system comprising two cleaning apparatuses that are alongside one another and functionally integrated;

Fig. 4 shows a cleaning system of turnable type;

Fig. 5 shows a multiple-station cleaning system of tunnel type which does not fall under the scope of the claims.

DETAILED DESCRIPTION OF THE INVENTION

[0016] With reference to figures 1 and 2 the general features of a cleaning apparatus according to the invention will now be disclosed, suitable for cleaning bags for containing loose products; nevertheless, what will be said here below with reference to the cleaning of bags in general must be understood to apply to the external cleaning of any type of container.

As shown, the cleaning apparatus 10 according to the example in figures 1 and 2 comprises a table 13 for supporting a bag 12, in combination with a robot 11 for moving dirty bags to be cleaned from a pallet and for transferring the dirty bags to the support table 13.

The support table 13 for the bag 12 to be cleaned can be configured in any manner provided it is suitable for enabling the bag 12 to be cleaned by a plurality of jets of a fluid directed upwards, through a plurality of passage openings of the support table 13; in this regard, the support table 13 can consist of a tough metal grid or can comprise a plurality of holes at a spraying zone for cleaning the bags 12, schematically indicated by reference 14 in figure 1, or can consist of idle or driven rollers, or of a table of brushes configured for enabling a cleaning fluid to be sprayed.

[0017] Still with reference to figures 1 and 2, the device 11 for removing and transferring the bags 12 has been schematically represented in the form of a robot; [0018] The table 13 for supporting and for cleaning the bags 12 is supported by a hopper 15 for collecting the cleaning fluid and polluting substances that fall, dragged by the fluid, whereas they are removed by jets of fluid during a cleaning step for the bags. If the cleaning fluid is a liquid, the hopper 15, in addition to collecting the sludge, is also used to contain the excess liquid; if desired, in certain cases the hopper 15 for collecting the cleaning fluid and polluting substances can operate in a slight vacuum condition by connecting the hopper 15 to a suitable air sucking device.

[0019] Inside the hopper 15, at the spraying zone 14 and the table 13 supporting the bags 12, a plurality of lower spray nozzles 16 oriented upwards are provided and connected to a suitable source 17 of a pressurised cleaning fluid of the type referred to previously; the pressurised jets of fluid that exit the nozzles 16, through the meshes of the grid or openings of the table 13, are directed upwards against the lower and the side surfaces of the bag 12, removing the dirt and the polluting substances, which are dragged by the fluid until they fall into the hopper underneath.

In addition to the lower spray nozzles 16, it is possible to provide a plurality of upper spray nozzles 18 oriented downwards, to clean the side of the bag 12 facing upwards. The upper spray nozzles 18 are fixed to a side of a holding head 19 for removing the bags 12, the holding head 19 being fixed to the articulated arm of the robot 11. The holding head 19 can be of any type, for example a mechanical or pneumatic head that can be moved vertically and/or horizontally, as shown.

[0020] In addition to fluid-jet cleaning of the bags 12, the cleaning apparatus 10 can be optionally provided with one or more mechanical cleaning devices; in the case shown in figure 2, a first mechanical cleaning device 20 schematically represented on the front side of the support table 13, consisting, for example, of a rotating brush, and a second mechanical cleaning device on the rear side of the table 13, for example consisting of a rotating brush 21 fixed to the stem of a linear actuator or pneumatic cylinder 22; thus the brush 21 can be moved longitudinally in contact with the bag 12. Alternatively to or in combination with the mechanical cleaning devices shown, any other mechanical cleaning device can be used.

[0021] It has been specified that the cleaning apparatus according to the present invention, in addition to preventing contamination of the substance contained in the bag 12, also has to be able to prevent repollution of the bag or container 12 during the cleaning step, and to prevent the dispersal of polluting substances externally; thus, according to another feature of the cleaning apparatus 10, above the table 13 for supporting and cleaning the bags 12, air-sucking means are provided along the peripheral edges of the support table 13 for the bags.

[0022] In the case shown in figures 1 and 2, the air-sucking devices consist of sucking walls 23 that extend upwards on the two longitudinal sides and on the rear transverse side of the table 13, forming a protective barrier.

[0023] For example, the sucking walls 23 can consist of hollow walls, having on the internal side facing the cleaning zone 14 provided with sucking holes or slits 24, as shown in figure 2; the hollow walls 23, above or on an external side have a hole 25 for connection to a system of sucking conduits. Lastly, in figure 1, with reference 26 two side bars are indicated for centring the bags 12 on the table 13, at the cleaning zone 14.

[0024] The operation of the cleaning apparatus disclosed is briefly as follows: robot 11, after removal of a dirty bag 12, deposits the dirty bag 12 on the cleaning zone 14 of the support table 13; during the insertion of the bag 12, the lower side thereof can be partially cleaned by the brush 20, if present.

[0025] Once the bag 12 has been deposited on the table 13 and released by the holding head 19 of the robot 11 at the cleaning zone 14, both the lower spray nozzles 16 and the upper spray nozzles 18 are activated, the latter moving by means of the articulated arm of the robot 11; obviously, the drive sequence of the lower and upper spray nozzles can also be different from the drive sequence referred to above. Whilst the cleaning fluid is being sprayed, the rotating brush 21 can be moved by the actuator 22.

[0026] Once spray nozzles 16 and/or 18 have been activated, the washing fluid that is sprayed against the bag 12 at a certain pressure, removes all the dirt and the polluting substances that have adhered over time, or have been deposited on the bag, which are dragged by the cleaning fluid so as to fall into the collecting hopper 15. During the spraying step of the cleaning fluid, the air sucking walls 23 are activated, preventing the dirt or polluting substances suspended in the air from being able to fall and again contaminate the bag 12, or the exterior.

[0027] When the operation of cleaning a bag 12 has terminated the robot 11 is again driven to remove the clean bag and deposit the bag in a collecting point, from which it is moved to a subsequent opening and emptying step; at this point the operative cycle can be started again to clean another bag 12.

[0028] As mentioned before, the disclosed cleaning apparatus permits a high degree of integration and automation to significantly reduce work times; this can be illustrated with reference to the examples of the remaining figures.

[0029] In figure 3 a system has been shown comprising two cleaning stations 10Aand 10B that are alongside one another, consisting of cleaning apparatuses similar to or completely identical to those of figures 1 and 2; thus also in figure 3 the same reference numbers have been used to indicate similar or equivalent parts. For reasons of drawing simplicity, in figure 3 the robot 11 has not been shown that alternatively serves the two stations 10Aand 10B, as explained before. Further, in figure 3 with 30 and 31 the removing and/or deposition point for the bags 12A and 12B has been indicated.

[0030] The operative method of the cleaning system of figure 3 is completely similar to that of the apparatus of figures 1 and 2, with the only difference that now a single robot 11 is used to serve in sequence the two cleaning stations 10A and 10B, in this way enabling a higher automation degree and a consequent reduction of the work cycle.

In brief, the system operates in the following manner: as mentioned previously, a single robot that is not shown, for moving and transferring the bags 12, removes a bag 12Afrom the removal point 30 and positions the bag 12Ain the spraying zone 14 of the station 10A, where it is subjected to cleaning by spray jets of gas and/or liquid, and to a possible mechanical brushing action, depending on the type of bag and/or of the contents thereof; during the cleaning operation, the dirt or possible polluting substances become detached from the bag, most fall into the hopper 15 underneath, with the same cleaning fluid, and partially, if they are present in the air, they are sucked by the walls 23.

[0031] The robot, after taking and positioning a dirty bag 12A in the axially aligned cleaning station 10A, immediately afterwards removes a clean bag 12B from the station 10B, which in the meantime has completed the cleaning operations, and after depositing the bag, replaces the clean bag with a new bag to be cleaned.

[0032] During the removing step and replacing a clean bag 12B, the cleaning operation of the bag 12Ain the station 10Ais completed; then the robot removes the clean bag from the station 10A and replaces the clean bag with a new bag to be cleaned. The removing and cleaning operations of the bags 12A and 12B are then repeated in sequence in the two stations 10A and 10B, as disclosed previously.

The figure 4 shows a second solution, still relating to a double cleaning system, in which the two stations 10A and 10B are axially aligned and are integrated into a single structure 32 rotatably around a vertical axis 33 operationally connected to a rotary actuator 34; also in figure 4 the same reference numbers as the previous figures have been used to indicate similar or equivalent parts. The support structure 32 of the two cleaning stations 10Aand 10B can rotate in a single direction or alternatively in the two opposite directions, providing in both cases a suitable rotating distributor connecting nozzles 16 to a source of pressurised cleaning fluid. Also in this case, a single robot for removing and transferring the bags, which is not shown, can be provided as in the previous cases, further, both the cleaning stations 10Aand 10B can be optionally provided with mechanical cleaning devices, for example of the roller type, as in the previous cases.

The operation of the cleaning system of figure 4 is substantially similar to that of figure 3, with the sole difference that now the dirty bags or containers are loaded, and the clean bags or containers are unloaded with the supporting structure 32 of the two cleaning stations 10Aand 10B that is stationary and in a position aligned with the loading and unloading device, whereas the cleaning operation can be initiated and made to continue during rotation. Also in this case system productivity and versatility is increased, enabling in all cases the desired objects to be achieved.

Figure 5 shows a further solution in which the single bags 12 are moved along a cleaning path in a tunnel type system, comprising a plurality of successive cleaning stations 10A, 10N, in each of which a determined cleaning, washing and/or sterilisation operation can be performed with a suitable gaseous and/or powder fluid, depending on the case.

[0033] Also in this latter case the cleaning system is served by a single robot for removing and transferring the bags, which is not shown, which loads the dirty bags at one end A of the cleaning line and unloads the clean bags at the other end B; again in figure 5 the same reference numbers have been used to indicate parts that are similar or equivalent to those of the preceding figures.

In this respect, as shown in figure 5, the cleaning line extends along a U-shaped path, i.e. a path comprising a first linear portion 35A along which the bags 12 are advanced in one direction by a first conveyor 36A, for example of the roller type, and a second linear portion 35B, alongside and parallel to the previous one, along which the bags 12 are advanced in a direction opposite the previous one, for example by a second roller conveyor 36B; the rollers of the two conveyors 36A and 36B, in a manner that is per se known, are operationally connected to a driven reduction unit by a suitable chain or other type of transmission, which is not shown.

[0034] The bags 12 can be transferred from the portion 35Ato the portion 35B of the cleaning system in any manner, for example by a transverse conveyor 37 of the belt type, or in another manner.

[0035] Again, the air sucking walls 23 are provided peripherally on the external and internal sides of the two portions 35A and 35B of the cleaning line, as shown, again making use of the same reference numbers to indicate similar or equivalent parts.

[0036] In figure 5, three cleaning stations 10 have been shown along each portion 35A and 35B providing spray nozzles 16 and hoppers for collecting the fluid and the pollutants independent for each axially aligned cleaning station, or common to several stations 10, depending on design requirements and needs.

[0037] The operation of the cleaning system of figure 5 is briefly as follows: the dirty bags 12 are loaded singularly onto the front end A of the first portion of line 35A, and are then made to advance by the roller conveyor 36A, through the three cleaning stations 10 where they are washed and cleaned with a same or with different types of cleaning fluids, undergoing possible brushing in the intermediate axially aligned cleaning station by means of one or more rotating brushes 21.

[0038] The single bags 12, already partially cleaned, when they arrive at the rear end of the first portion of line 35A, opposite the loading end, are transferred by the transverse belt conveyor 37 to the rear end of the second cleaning line portion 35B along which they are made to advance by the second roller conveyor 36B, in a direction opposite the previous connection. Whilst the single bags 12 advance along the second portion of line 35B they undergo further cleaning treatments in the various spraying stations 10, reaching the final unloading station 10N.

[0039] It is clear that, depending on the type of bag or container 12, of the material with which the bag or container 12 is made, on the type of substance, whether liquid, powder or in pasty state, contained in the single bags or containers 12, and on the type of dirt or pollutant to be cleaned, each portion 35A and 35B of the cleaning line comprise a greater or lesser number of stations 10 than those shown, providing a number and type of spray nozzles that are the same or different for each axially aligned cleaning station 10, depending on the different needs with regard to cleaning the bags or containers 12.

[0040] What has been said and shown with reference to the examples of the enclosed figures has been provided by way of illustrative example of the technical features of the cleaning apparatus 10, and of the entire system; accordingly other modifications or variations can be made to the cleaning apparatus of figure 1 or to the single cleaning stations of the entire system, without departing from the claims.

REFERENCES CITED IN THE DESCRIPTION

This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description

• US2007Q56612A1 rOOOSI • DE4332857A1 [00101

Claims

1. Apparat (10), som er egnet til udvendig rengøring af beholdere (12) til løse stoffer, hvor beholdernes (12) udvendige overflade er forurenet med snavs og/eller med forurenende stoffer, som skal fjernes før åbning af beholderne (12), hvilket apparat omfatter: et bord (13), som understøtter beholderne og har mindst én sprøjtezone (14) til et rengøringsfluid, konfigureret med en flerhed af passageåbninger til fluidet, en flerhed af nedre sprøjtedyser (16) til rengøringsfluidet, under sprøjtezonen (14') af støttebordet (13) til beholderne (12), en tragt (15) til opsamling af rengøringsfluid, snavs og/eller det forurenende stof, som fjernes fra beholderne (12), og beskyttende og luftsugende sidevægge (23), som er perifert arrangeret på støttebordet (13) til beholderne (12), øvre sprøjtedyser (18) til et rengøringsfluid, i position over støttebordet (13) til beholderne (12), kendetegnet ved, at de øvre sprøjtedyser (18) er bevægeligt understøttet langs sprøjtezonen (14) af støttebordet (13) til beholderne (12), en robot (11) er tilvejebragt til fjernelse og overførsel af beholderne (12), og de øvre sprøjtedyser (18) er fastgjort til en side af et holdehoved (19) til fjernelse af beholderne (12), idet holdehovedet (19) er fastgjort til en leddelt arm af robotten (11).Apparatus (10) suitable for the external cleaning of containers (12) for solids, the outer surface of the containers (12) being contaminated with dirt and / or with pollutants to be removed before opening the containers (12) , comprising: a table (13) supporting the containers and having at least one spraying zone (14) for a cleaning fluid configured with a plurality of passage openings for the fluid, a plurality of lower spraying nozzles (16) for the cleaning fluid, below the spraying zone (14 ') of the support table (13) for the containers (12), a hopper (15) for collecting cleaning fluid, dirt and / or the pollutant which is removed from the containers (12), and protective and air-sucking side walls (23) which are peripherally arranged on the support table (13) for the containers (12), upper spray nozzles (18) for a cleaning fluid, in position over the support table (13) for the containers (12), characterized in that the upper spray nozzles (18) are movably supported along the spray zone one (14) of the support table (13) for the containers (12), a robot (11) provided for removal and transfer of the containers (12), and the upper spray nozzles (18) being secured to one side of a holding head (19) for removing the containers (12), holding the holding head (19) to an articulated arm of the robot (11).

2. Apparat (10), som er egnet til udvendig rengøring af beholdere (12), ifølge krav 1, kendetegnet ved at omfatte mindst én mekanisk indretning (20, 21) til rengøring af beholderne (12).Apparatus (10) suitable for external cleaning of containers (12) according to claim 1, characterized by comprising at least one mechanical device (20, 21) for cleaning the containers (12).

3. Apparat (10), som er egnet til udvendig rengøring af beholdere (12), ifølge krav 2, kendetegnet ved, at den mekaniske rengøringsindretning (21) er bevægelig langs med støttebordet (13) til beholderne (12).Apparatus (10) suitable for external cleaning of containers (12) according to claim 2, characterized in that the mechanical cleaning device (21) is movable along the support table (13) for the containers (12).

4. Apparat (10), som er egnet til udvendig rengøring af beholdere (12), ifølge et hvilket som helst af kravene 1 til 3, kendetegnet ved, at de beskyttende vægge (23) består af hule vægge, idet en side af de beskyttende vægge (23), som vender mod sprøjtezonen (14), er konfigureret med en flerhed af luftsugeåbninger (24).Apparatus (10) suitable for external cleaning of containers (12) according to any one of claims 1 to 3, characterized in that the protective walls (23) consist of hollow walls, one side of the protective walls (23) facing the spray zone (14) are configured with a plurality of air suction openings (24).

5. Apparat (10), som er egnet til udvendig rengøring af beholdere, ifølge et hvilket som helst af kravene 1 til 4, kendetegnet ved at omfatte centreringselementer (20) til centrering af beholderne (12) ved sprøjtezonen (14).Apparatus (10) suitable for external cleaning of containers according to any one of claims 1 to 4, characterized by comprising centering elements (20) for centering the containers (12) at the spray zone (14).

6. Apparat (10), som er egnet til udvendig rengøring af beholdere (12), ifølge krav 1, kendetegnet ved, at tragten (15) er operativt forbundet med en luftsugeindretning.Apparatus (10) suitable for external cleaning of containers (12) according to claim 1, characterized in that the hopper (15) is operatively connected to an air suction device.

7. System, som er egnet til udvendig rengøring af beholdere (12) til løse stoffer, hvor beholdernes (12) udvendige overflade er forurenet med snavs og/eller med forurenende stoffer, der skal fjernes før åbning af beholderne (12), hvilket system omfatter: første og anden borde (13), som understøtter beholderne og har mindst én sprøjtezone (14) til et rengøringsfluid, konfigureret med en flerhed af passageåbninger til fluidet, en flerhed af nedre sprøjtedyser (16) til rengøringsfluidet, under sprøjtezonen (14') af hvert understøtningsbord (13) til beholderne (12), en tragt (15) til opsamling af rengørings fluid, snavs og/eller det forurenende stof, som fjernes fra beholderne (12), og beskyttende og luftsugende sidevægge (23), som er perifert arrangeret på hvert støttebord (13) til beholderne (12), øvre sprøjtedyser (18) til et rengøringsfluid, i position over støttebordet (13) til beholderne (12), kendetegnet ved, at de øvre sprøjtedyser (18) er bevægeligt understøttet langs sprøjtezonen (14) af støttebordet (13) til beholderne (12), hvor en robot (11) er tilvejebragt til fjernelse og overførsel af beholderne (12) til og fra bordene (13), og hvor de øvre sprøjtedyser (18) er fastgjort til en side af et holdehoved (19) til fjernelse af beholderne (12), idet holdehovedet (19) er fastgjort til en leddelt arm af robotten (11).A system suitable for the external cleaning of containers (12) for solids, the outer surface of the containers (12) being contaminated with dirt and / or with contaminants to be removed before opening the containers (12), comprises: first and second tables (13) supporting the containers and having at least one spray fluid (14) for a cleaning fluid configured with a plurality of fluid passage openings, a plurality of lower spray fluid nozzles (16), below the spray zone (14); ) of each support table (13) for the containers (12), a hopper (15) for collecting cleaning fluid, dirt and / or the pollutant which is removed from the containers (12), and protective and air-sucking side walls (23) which is arranged peripherally on each support table (13) for the containers (12), upper spray nozzles (18) for a cleaning fluid, in position over the support table (13) for the containers (12), characterized in that the upper spray nozzles (18) are movable underneath supported along the spray zone (14) of the support table (13) to the containers (12), where a robot (11) is provided for removing and transferring the containers (12) to and from the tables (13), and wherein the upper spray nozzles (18) is attached to a side of a holding head (19) for removing the containers (12), the holding head (19) being attached to an articulated arm of the robot (11).

8. System, som er egnet til udvendig rengøring af beholdere, ifølge krav 7, kendetegnet ved at omfatte et første og mindst et andet støttebord (13), som er parallelt arrangeret ved siden af hinanden.System suitable for external cleaning of containers, according to claim 7, characterized by comprising a first and at least a second support table (13) arranged parallel to one another.

9. System, som er egnet til udvendig rengøring af beholdere (12), ifølge krav 7, kendetegnet ved at omfatte et første og et andet aksialt anbragt støttebord (13), hvor nævnte støtteborde (13) er integreret i en roterende konstruktion (32) i forhold til en lodret akse (33).System suitable for external cleaning of containers (12) according to claim 7, characterized by comprising a first and a second axially arranged support table (13), wherein said support tables (13) are integrated in a rotating structure (32). ) relative to a vertical axis (33).