The present invention relates to an apparatus and a method for filling containers.
The common classification of disposable containers is the following:
In particular, the present invention relates to the sector of filling disposable container of medium medium-large format, i.e. with capacity between about five and twenty litres.
It should be noted that the technologies in use in the bottling industry differ according to the format of the processed containers.
For large-format containers, e.g. five gallons and more, linear filling machines are used.
For medium-format containers, two different filling technologies are in use today, as productive capacity changes:
The linear filling technology is conditioned by two fundamental problems:
To date, point "a" is confronted in two ways in the industry: either by using augers that distance the bottles (which, however, are bulky, costly, and do not allow the creation of a filling environment with high cleanliness assurance) or through mechanical or pneumatic bottle spacing systems (hard to adjust for different formats and hazardous from the hygiene viewpoint, because they are difficult to sanitise, given the high number of "dead comers", possible sites for bacterial colonies). Point "b", instead, is confronted either by waiting for the row of filled bottles to exit from the filling area (for the bottles exit along the same direction in which they are arranged during the filling and along which they are into the area), with consequent high idle time of the machine and reduction of the hourly productive capacity, or by pushing the bottles immediately after they are filled (in order to free the filling taps as quickly as possible) on a parallel belt able to extract the bottles from the filling space.
However, such solutions do not satisfactorily solve the problem of the speed of the filling process, because they allow a maximum production of 3,000 bottles/hour, insufficient to satisfy production capacities of up to 8,000 bottles/hour, typical of the medium-format sector (e.g., 5 Lt). This type of technology does, nonetheless, have some pluses, such as simplicity of construction (with consequent cost reduction) and ease of maintenance. To reach production rates of 8,000 bottles/hour in the sector of medium formats (and to fill small-format containers, typically at production rates from 5,000 bottles/hour to 50,000 bottles/hour for 0.5 and 1.5 1 bottles), a technology known as rotary is used; i.e., the containers are fed continuously (after being distanced for medium formats by means of an auger) and a filling carrousel having a plurality of nozzles positioned along a circumference of the carrousel and rotating with it. Therefore, the filling operation takes place during the rotation of the containers integrally with the carrousel.
This type of solutions, i.e. the so-called rotary technology, has the advantage of allowing a high production rate (up to 8,000 bottles/hour for medium formats) but is still has also some drawbacks.
First of all, the diameter of the carrousel increases as the size of the containers to be processed increases for equal production rates; this is a particularly severe problem for filling containers of at least 5 1. Moreover, said rotary filling apparatuses are constructively complex, hard to maintain and complex to sanitise.
An additional drawback of known filling machines (both linear and rotary) is that they present considerable difficulties and problems if they have to be adapted to the processing of containers with different formats, for:
It is also known from document
An object of the present invention is to eliminate the aforesaid drawbacks and to make available an apparatus and a method for filling containers that enable to process medium-size containers with a particularly high hourly production rate.
Another object of the present invention is to allow to process different-format containers in a particular simple and efficient manner.
Said object is fully achieved by the apparatus of the present invention, which is characterised by the content of the appended claims and in particular in that it comprises, in combination:
The method according to the present invention is characterised in that it comprises the following steps:
This and other characteristics shall become more readily apparent from the description that follows of a preferred embodiment, shown purely by way of non limiting example in the accompanying drawing tables, in which:
In the figures, the numeral 1 indicates an apparatus for filling containers 2, constituted for example by PET bottles.
The containers 2, in particular, are containers of medium size, i.e. with a capacity of between 5 litres and 20 litres.
The apparatus 1 comprises a central conveyor 3 positioned along a central longitudinal axis 4.
The central conveyor 3 conveys the empty containers 2 to be filled from a feeding station 5 to a collection station 6.
The containers 2 are positioned on the central conveyor 3 aligned longitudinally and they are conveyed in a row.
The central conveyor 3, originally, comprises:
The fingers 8, actuated by the belts 9, push the containers 2 along the track 7. In particular, the two belts 9 are parallel in such a way as to define a plurality of pairs of teeth 8 fastened on the respective belts and aligned transversely. In this way, each container 2 is pushed by a pair of fingers 8.
The fingers 8 fastened to a belt are longitudinally distanced from each other by a predetermined quantity, corresponding to the longitudinal distance between the containers 2 in the collection station 6.
The apparatus 1 also comprises, originally, a first series of filling nozzles and a second series of filling nozzles 11 arranged on respective longitudinal rows at the sides of the central conveyor 3 and oriented downwards.
Moreover, the apparatus 1 originally comprises a first lateral conveyor 12 and a second lateral conveyor 13 positioned longitudinally (hence parallel to the central conveyor 3) at the opposite sides of the central conveyor 3.
The first lateral conveyor 12 is positioned underneath the first series of filling nozzles 11, to define a first filling station. Similarly, the second lateral conveyor 13 is positioned underneath the second series of filling nozzles 11, to define a second filling station.
In the preferred embodiment illustrated herein, each of said first and second lateral conveyor comprises a pair of conveyor belts arranged longitudinally, parallel to each other and parallel to the central conveyor 3.
In particular, the first lateral conveyor 12 comprises a first conveyor belt 14 positioned under the filling nozzles 11 to define the first filling station and a second conveyor belt 15 flanking the first one laterally and externally thereto, relative to the central conveyor 3.
Similarly, the second lateral conveyor 13 comprises a first conveyor belt 16 positioned under the filling nozzles 11 to define the second filling station and a second conveyor belt 17 flanking the first one laterally and externally thereto, relative to the central conveyor 3, whereon are thrust the bottles once they are filled to free the filling area.
It should be noted that the apparatus according to the present invention is symmetrical relative to the central longitudinal axis 4.
The second conveyor belts 15 and 17 are external relative to the first ones 14 and 16.
Moreover, the lateral conveyors 12 and 13 originally comprise a plurality of foils 18 arranged vertically and positioned (in the transverse sense) above the first conveyor belts 14 and 16 and (in the longitudinal sense) in intermediate position between a filling nozzle 11 and the next one. The foils 18 are oriented in such a way as to form an angle of about 30 degrees with a longitudinal axis oriented in the direction of movement of the containers. In this way, the foils 18 define guide elements able to deviate the trajectory of the containers 2 being transferred towards the exit to move them (for each of the two lateral conveyors 12 and 13) from the first to the second conveyor belt.
Moreover, the apparatus 1 comprises, originally, a first assembly 19 for moving containers 2 from the collection station to the first filling station and a second assembly 20 for moving containers 2 from the collection station to the second filling station.
In the preferred embodiment illustrated herein, each moving assembly 20 comprises a frame 21 (e.g. a tubular body or a shaft) rotating around its own longitudinal axis.
It should be noted that the two frames 21 are positioned between the central conveyor 3 and the lateral conveyors 12 and 13.
Each frame is provided with a plurality of arms 22 fastened to the frame; the arms 22 are in a number equal to the nozzles 11 and they are perpendicular to the longitudinal axis of rotation of the frames 21.
To each arm 22 is slidably coupled a cylinder 23, so that the cylinder 23 can retract and extend from the end of the arm itself. To one end of each cylinder 23 is pivotally coupled a pincer 24; in this way, the pincers 24 are rotatable around the axes defined by the respective arms and they are also movable in extension or retraction along said axes.
Each pincer 24 is movable between a closed position, for gripping a container 2, and an open position, of non interference with the container itself.
To actuate the frames 21 (rotating them), the cylinders 23 (making them slide relative to the arms 23) and the pincers 24 (rotating them relative to the cylinders), electric or pneumatic actuators are provided (not shown because they are of a substantially known kind).
The central conveyor 3 operatively stops in such a way as to position a row of containers aligned in predetermined positions, in the collection station (in such a way that they can be taken by the moving assemblies and moved in the filling sites). In the preferred embodiment illustrated herein, in the collection site each container 2 is aligned with an arm 22 and with a nozzle 11 along a transverse axis.
Said first and second moving assembly are operatively active on a first and on a second subset of said plurality of containers 2 in the collection site, to move them in the first and in the second filling station, respectively.
Originally, each of said subsets of containers 2 comprises non consecutive containers 2.
In the preferred embodiment illustrated, the distance between two consecutive arms 22 of a same moving assembly is substantially double relative to the distance between the axis of the two consecutive containers 2 in the row of containers 2 present in the collection station. In this way, if one were to imagine numbering the containers from the first to the last one, the first moving assembly moves the odd-numbered containers 2 and the second moving assembly moves the even-numbered containers 2, or vice versa.
Therefore, said first and second moving assemblies constitute moving means operatively active on the containers 2 to move them from the central conveyor 3 in the collection site to the lateral conveyors 12 and 13 in the filling stations where the containers 2 are arranged with their mouths aligned to corresponding filling nozzles 11.
The movement of each container 2 entails a rotation of the container 2 around a longitudinal axis (the axis of rotation of one of the frames 21); in the absence of further rotations, at the end of said rotation the container would be situated in one of the filling stations in upside-down position with the mouth oriented downwards. Therefore, the movement of each container 2 entails an additional rotation of the container 2 around a transverse axis (the axis of one of the arms 22).
The cylinders 23 allow to move the containers transversely. This advantageously allows to perform the rotation of the container around the transverse axis after the rotation around the longitudinal axis (although in principle the rotations could be performed simultaneously, but with the drawback of making it less simple and safe to handle the containers 2), without having the container 2 interfere with the nozzles 11 during this latter rotation.
In practice, said rotations are performed with the cylinders 23 retracted; subsequently, the cylinders 23 are extracted to bring the containers into alignment with the nozzles 11.
It should be noted also that according to an embodiment variant, the pincers 24 are movable vertically (e.g. associating the moving assemblies to the structure by means of vertical slide guides), to lift the containers vertically in the filling station. According to an additional variant, the nozzles 11 are movable vertically through a substantially known system for raising and lowering the nozzle.
Both said solutions, which may be used alternatively to each other, enable to place the mouths of the containers in contact with the nozzles 11 during the filling step, possibly pressing the mouths on the nozzles to achieve a seal, to conduct a gravity-fed filling operation, with no need for volumetric metering.
In any case, in the preferred embodiment illustrated, nozzles 11 are used which are able to perform a filling operation with volumetric dosage, so that it is not necessary for the mouths of the containers to be in contact with the nozzles, but it is sufficient for them to be aligned.
With regard to the lateral conveyors, they, in addition to defining the filling station, convey the full containers out of the apparatus.
In this light, it should be noted that the presence of the dual conveyor belts and of the foils 18 entails a considerable saving of time. To move the containers from the first (inner) belts to the second (outer) belts, it is sufficient for the belts to move together by smaller quantity that the distance between a container and the next one (i.e. between a nozzle and the next one); once the full containers 2 are on the second belts, the first belts (which define the filling stations) are ready to receive new empty containers to be filled, whilst the second belts continue to carry the containers towards the exit from the apparatus.
Moreover, the apparatus 1 comprises a system for regulating the vertical height of the surfaces whereon the containers 2 bear, i.e. the surfaces defined by the central conveyor 3 and by the lateral conveyors 12 and 13; said central conveyor 3 and lateral conveyors 12 and 13 are integral with a flat bed for supporting the structure of the apparatus which, raising and lowering under the command of a PLC or other regulating means, adapts the height of the lateral conveyors 12 and 13 according to the height of the different format.
In particular, the bearing surfaces of the containers 2 defined by the lateral conveyors 12 and 13 are movable vertically towards and away from the nozzles 11.
This advantageously allows easily to adapt the apparatus to the processing of containers 2 of different sizes, e.g. by operating an active command on the PLC.
In this light, it should also be noted that the fact that the central conveyor 3 is provided with fingers 8 to push the containers 2 entails the advantage of avoiding any intervention or modification on the apparatus to adapt it to the processing of containers of different size.
The fingers 8 are able to move any container from 5 to 20 Lt without any format-change operation and the only adjustment to make pertains to the stop position of the central conveyor 3 in the point of grip of the pincer (which changes with container size), which is determined automatically when the aforementioned PLC push-button is pressed.
The present invention also makes available a method for filling containers 2, and in particular containers of medium dimensions (from 5 to 20 litres).
Said method originally comprises the following steps, repeated in succession:
It should be noted that
In particular, in the moving step a first and a second subset of said plurality of containers 2 are moved from the collection station 6 to the first and to the second filling station, respectively, each subset of longitudinally aligned containers comprising non consecutive containers. Moreover, the moving step preferably comprises:
The step of conveying the full containers 2 out of the apparatus preferably comprises a step of deviating the trajectory of the containers 2 to move them laterally away from the central longitudinal axis 4, in such a way that said lateral longitudinal axes of conveyance of the exiting containers 2 are distanced transversely by predetermined quantities relative to the respective filling stations.
The moving step takes place through moving assemblies 19 and 20 active on the containers 2 by means of pincers 24.
It should be noted that, in the filling step, the pincers 24 preferably remain gripping for a predetermined waiting time (corresponding to a first part of the filling step, e.g. about 3 sec.), to assure a stabilisation of the containers 2 until the quantity of liquid introduced into the containers 2 in the filling step is sufficient to make the containers stable.
It should also be noted that, during the filling step, the containers are raised vertically or the nozzles 11 are lowered vertically to place the mouths of the containers in contact with the nozzles 11, possibly pressing the mouths on the nozzles to achieve a seal. Said raising step advantageously enables to perform the filling operation by simple gravity.
During the filling step, after said waiting time, the pincers 24 move to the open position, releasing the containers 2 being filled; thereupon, the pincers 24 are brought back by the moving assemblies 29 and 20 to the collection station, to collect other empty containers to be filled. Therefore, the step of filling a plurality of containers 2 and the step of moving a plurality of subsequent empty containers are, originally, partially superposed, thereby advantageously enabling to quicken the process.
In this light, it should also be noted that, from the time when a plurality of containers is full, at the end of the related filling step, the filling stations are able to receive new containers after a particularly short time, given by the time needed to transfer the full containers from the first (inner) conveyor belts to the second (outer) conveyor belts. During said transfer, the first conveyors move; after said transfer, they are motionless. Said transfer time is made particularly short, originally, thanks to the presence of the foils 18.
Therefore, the present invention allows to fill medium-size containers (from about 5 to about 20 litres) in a particularly efficient and advantageous manner, exploiting a modified linear technology to achieve particularly high performance levels in terms of speed.
Lastly, the present invention enables to fill medium-sized containers with an hourly production of over 6,000 containers per hour,
whilst maintaining the containers motionless during the filling operation and filling them with fixed nozzles.
This result is originally obtained thanks to the fact that the containers are filled in filling stations that are offset transversely relative to the longitudinal axis along which the empty containers are fed. Moreover, the filling process is further accelerated thanks to the fact that the full containers are conveyed out along longitudinal axes that are offset transversely relative to the filling stations.
It should be noted that using a substantially linear filling technology advantageously enables the filling apparatus to be of reduced size, easy to maintain and particularly simple to sanitise.
Moreover, the present invention advantageously enables to process containers with different formats in a particularly efficient manner, allowing a format change in particularly rapid fashion, because it does not require to replace any components (feeding augers or stars or counter-guides) but simply to press an active control on the PLC.
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.