EP0751067B1 - Automatic filling machine for valve bags - Google Patents

Description

The invention relates to an automatic bag filling machine for valve. In particular it relates to an apparatus for filling plastic bags automatically with liquids.

Valve bags are known. EP-A-104406 describes a plastic bag provided a valve or equivalent system for filling bulk goods.

• agripper les sacs un par un,
• ouvrir la valve,
• remplir le sac,
• agripper à nouveau le sac plein afin de l'emballer et/ou l'expédier.

The filling of valve bags normally requires different stages, namely:

• grab the bags one by one,
• open the valve,
• fill the bag,
• grab the full bag again to pack and / or ship it.

All these manipulations are boring and require a lot of workforce. Automation of valve bag filling is therefore desirable.

US Patent A-3691715 to St. Regis Paper Company discloses a machine automatic filling of valve bags; however, different technical details (discussed below) show that this document concerns exclusively paper bags, as confirmed by the name of the licensee.

Patent application EP-A-97415 discloses another automatic machine for filling with valve bags which includes the technical elements of the preamble of the claim 1; although the use of plastic bags is planned, the device proposed by this document is not well suited to it (thus as discussed below).

In fact, known machines pose various problems (especially from the point reliability) when trying to use them with plastic, especially with poly bags and all especially in low density polyethylene, because of the properties very different from paper.

An object of the invention is therefore to provide a machine more reliable than the known machines.

Furthermore, attempts to remedy the unreliability of known machines have resulted in a relatively structured structure complex and therefore more expensive to purchase and maintain.

Another object of the invention is therefore to provide a simpler machine than known machines.

An additional disadvantage of known machines is that they do not not allow you to control the orientation of full bags, which is particularly troublesome if you want to automate palletizing for the expedition.

Yet another object of the invention is therefore to provide a machine which controls the orientation of full bags for packaging operations.

The automatic filling machine of the present invention responds to these goals and others.

The machine according to the present invention for the automatic filling of plastic valve bags is defined by the combination of features set out in claim 1.

According to the invention, the plastic bags 1 are found, folded with the valve 20 upwards, on support means 2 instead of storage and they are pulled down by several means of removal 4, thus passing between the support means 2; one or more means 4 'are firmly attached to a support 5 which can move vertically, and are located in the middle of the support means 2, while that other removal means 4 '' are attached to the support 5 so mobile, on both sides on its sides, so as to follow the deformation of the bags 1 (which is an essential element of the invention) when they are pulled down one by one by means 4. These means removal 4 are preferably suction cups, in particular conical cups in which a depression is produced to create the suction cup effect.

The particular arrangement of the removal means 4 according to the invention is essential; thus, documents US-A-3691715 and EP-A-97415 describe fixed means 36 and 38 respectively, which are not optimal for plastic bags, especially for poly bags and more particularly in low density polyethylene. Attempts carried out showed that such arrangements did not allow reliably remove the bags one by one.

According to another characteristic of the invention, the bags 1 are deposited one by one on an alignment plate 8 with the valve 20 upwards. Preferably the alignment plate 8 is provided with alignment means 11 in order to place the bag 1 'in a precise position. These means of alignment contribute significantly to the reliability of the machine according to the invention, particularly for polyethylene bags low density that slide easily.

According to yet another characteristic, removal means 13 (of preferably suction cups) lift the bag 1 'from the bottom, on the side of the valve, until it hangs and opening means 15 open the valve 20 (preferably while handles 14 hold the bag 1 '). The opening means 15 preferably consist of a part which pushes the valve 20 at the appropriate place to keep it open.

As the bags have been folded for a long time, they keep the memory of their shape. It is not a problem when the bags are filled at the hand, but it hinders or even prevents the machines from working automatic due to the irregular opening of valve 20. The solution to this problem is an inventive concept in itself: the 1 'bag suspended from the removal means 13, briefly apply (from preferably a sharp blow) of force by means of pressure 16 (preferably intermittent blowing means) in one direction such that each bag loses the memory of its folded shape. This operation greatly contributes to the fact that each bag 1 'is presented reliably in a reproducible position; we proceed from preferably before the opening means 15 push on the valve 20.

In general, the means 21 for filling the bags 1 consist of a filling pipe 21 introduced into the valve 20; once this pipe 21 has been introduced into the valve 20, the removal means 13 and the handles 14 can be detached _, leaving the bag 1 'hanging from the pipe 21. It is however preferable to continue to hold the bag 1' on the pipe 21 for a short time (for example 1 second) at the start of the filling process to prevent the bag 1 'from coming off the pipe 21. Preferably, the machine according to the invention also includes automatic means to prevent liquid does not come out through the filling pipe 21 in case the filling pipe 21 is not or is not properly inserted into the valve of the bag 1 '.

The use of the same removal means 13 since taking the bag 1 ' on the alignment table 8 until the introduction of the means of filling 21 in valve 20 represents a great simplification by compared to known machines.

According to a characteristic of the invention, the means for resuming at again the full bags 1 consist of plates (22, 23, 24, 25) which define a parallelepiped volume comprising the openings (permanent or temporary) suitable for letting bags pass 1 and the filling pipe 21. Preferably the means (22, 23, 24, 25) move together upwards, laterally and by pivoting (for relative to the pipe 21) in order to detach the bag 1 'from the filling pipe 21 and place it on the bottom plate 25 and on the plate 22, parallel to the main faces of the bag 1 '. Each bag is like this taken up in a constant orientation, which is essential for the continuation packaging operations (for example for placing on pallets).

The invention thus has an additional advantage over machines described in US-A-3691715 and EP-A-97415, in which the mechanism (not numbered and 108 respectively) to remove the bags full of the filling pipe does not allow to control their orientation.

Preferably, the bottom plate 25 is movably attached and swivels to let the full bag slide 1 ', preferably with the assistance of an upper layer made of fluoropolymer on the plate 25 and / or 22 and / or an air cushion between the bag 1 'and the plate 25 and / or 22. Each full bag can thus be taken up in a constant orientation by an automatic packaging system (e.g. for placing on pallets).

• La fig.1 montre un mode d'exécution des moyens pour agripper les sacs un par un du lieu de stockage (fig.1a: vue de face; fig.1b: vue latérale; fig.1c: vue du dessus);
• La fig.2 montre le fontctionnement d'une partie de la fig.1 (fig.2a: avant la prise d'un sac; fig.2b: pendant la prise d'un sac);
• La fig.3 montre un mode d'exécution du système d'alignement des sacs et des moyens pour les agripper à nouveau (fig.3a: vue du dessus; fig.3b: vue latérale);
• La fig.4 montre un mode d'exécution des moyens pour ouvrir la valve (fig.4a: vue du dessus; fig.4b: vue latérale; fig.4c et 4d: vue de face);
• La fig.5 montre un mode d'exécution des moyens pour remplir les sacs (fig.5a: vue de face; fig.5b: vue latérale);
• La fig.6 montre un mode d'exécution des moyens pour reprendre à nouveau les sacs pleins (fig.6a: vue du dessus; fig.6b: vue de face; fig.6c: vue latérale gauche);
• La fig.7 montre un mode d'exécution des moyens pour délivrer les sacs pleins en vue des opérations d'emballage (vue latérale; fig.7a: avec la plaque inférieure fermée; fig.7b: avec la plaque inférieure ouverte).

The invention is also described by means of the figures which illustrate specific embodiments of the invention, among which:

• Fig.1 shows an embodiment of the means for gripping the bags one by one of the storage location (fig.1a: front view; fig.1b: side view; fig.1c: top view);
• Fig.2 shows the operation of part of Fig.1 (Fig.2a: before picking up a bag; Fig.2b: while picking up a bag);
• Fig.3 shows an embodiment of the bag alignment system and means for gripping them again (fig.3a: top view; fig.3b: side view);
• Fig.4 shows an embodiment of the means for opening the valve (fig.4a: top view; fig.4b: side view; fig.4c and 4d: front view);
• Fig.5 shows an embodiment of the means for filling the bags (fig.5a: front view; fig.5b: side view);
• Fig.6 shows an embodiment of the means for resuming the full bags again (Fig.6a: top view; Fig.6b: front view; Fig.6c: left side view);
• Fig.7 shows an embodiment of the means for delivering the full bags for packaging operations (side view; fig.7a: with the bottom plate closed; fig.7b: with the bottom plate open).

In fig. 1, the bags 1 are stacked folded in a storage place, on support means 2, preferably two cylindrical rollers which can freely rotate around their axis, and they are of preferably guided by guide means 3, for example bars. According to the embodiment described in fig.1, the bags 1 are arranged with valve 20 upwards.

The removal means are described in fig.1 and 2. Part of the removal means 4 ′ are located in the middle of the support means 2, while the other 4 '' removal means are on both sides and else. The removal means 4 'are attached to a support 5 which can move vertically; the 4 '' removal means are attached to the support 5 movably by the hinge points 7 by means of mobile supports 6, which allows them to follow the deformation of the bag 1 when pulled down. The removal means 4 are preferably suction cups.

Fig.2a shows the support 5 and the removal means 4 for hanging a bag 1.

Fig.2a shows the support 5 and the removal means 4 after the attachment of the bag 1 ′, during the descent of the support 5. To follow the curvature of the bag 1 ', the mobile supports 6 of the removal means 4' 'have pivoted around the hinge points 7.

The distance between the support means 2 and the distance between the means removal 4 '' opposite are easily adapted to the stiffness of the bags 1.

Referring to fig.3, the support 5 and the removal means 4 descend with bag 1 'until bag 1' rests on a plate 8, also called the alignment plate. The alignment plate 8 is provided with an opening 9 adapted to the passage of the support 5 and the means removal 4. The bag 1 ′ is therefore always disposed with the valve 20 to the top.

The alignment plate 8 is also provided with openings 10 in which the alignment means 11, preferably shaped cylindrical, can move laterally to arrange the bag 1 'in a precise and reproducible defined position. Alternatively, and preferably, the alignment means 11 located on one side of the bag 1 ′ can remain stationary while the others can move to align the bag 1 '.

The alignment plate 8, which carries the bag 1 ′ in a precise position, then moves horizontally until the bottom of the bag 1 '(of the side of the valve) is under the removal means 13, which are preferably suction cups.

Referring to FIG. 4, the removal means 13 descend and take the bag 1 ', and then they go up at least until the bag 1 'hanger as described in fig.4b and 4c, with the handle 12 towards the low. It is advantageous to provide that the removal means 4 go back up without waiting take the next bag 1 '' in the place of storage, to avoid downtime.

The bag 1 'is then held firmly by two handles 14, while the valve opening means 15 open the valve 20 and the keep it open. The means 15 for opening the valve are made of a part (here shown in an elongated cylindrical shape) which pushes on the valve 20 in order to keep it open.

The handles 14 are then separated from one another, while the bag 1 'is hung from the removal means 13 and that the opening means 15 keep the valve 20 open. The bag 1 'hangs at this time as as shown in fig. 4d: as the bag has been folded for a long time, it tends to keep the memory of its folded shape.

Also, when the handles 14 are spaced from each other as shown in FIG. 4d, force is applied by means of the pressure means 16, here shown in the preferred form of a blowing device intermittent, so that the bag 1 'loses the memory of its shape and hang as shown in fig. 4c.

The bag 1 'hung as shown in fig.4c, with the valve 20 maintained opened by the opening means 15, the handles 14 are then again closed and the opening means 15 lifted, so that the valve 20 is kept open by an appropriate distance between the handles 14 and the removal means 13.

A filling pipe 21 is then introduced into the opening of the valve 20 (fig.5), preferably by lateral displacement of the bag 1 ', at less until the bag 1 'can hang alone on the hose filling 21, from which filling of the bag 1 'can start then the handles 14 and the removal means 13 can release the bag 1 '. It is advantageous to provide that the removal means 13 take without waiting for the next bag 1 '' on the alignment plate 8, to avoid downtime.

Automatic means are preferably provided in order to avoid that liquid does not leave through the filling pipe 21 in case a bag 1 'does not either not or not fully inserted on the filling pipe 21. By example, this can be done using a photocell attached to an appropriate place to detect a color difference between the bag 1 'and the filling pipe 21.

The filling of the bag 1 'is usually determined by the measurement volumetric of the quantity of liquid, possibly corrected by the taking into account the weight of the previous bags.

• la plaque 22 est parallèle au grand côté du sac 1' et porte les autres plaques (23, 24, 25);
• la plaque 23 se trouve du côté du tuyau de remplissage 21, est donc munie d'une découpe à sa partie supérieure (fig.6c), et est simplement fixée à la plaque 22;
• la plaque 24 se trouve du côté opposé au tuyau de remplissage 21 et est attachée de manière mobile sur la plaque 22, par exemple au moyen d'une charnière 34, pour laisser passer le sac 1' vide;
• la plaque 25 se trouve du côté inférieur du sac 1', et est attachée de manière mobile sur la plaque 22, par exemple au moyen d'une charnière 35, pour laisser glisser le sac 1' plein.

The full bag 1 'must now be taken up again and detached from the filling pipe 21 in order to pack it and / or send it. An embodiment for this is described in fig. 6. The full bag 1 ', still hanging from the filling pipe 21, is surrounded on four sides by the plates (22, 23, 24, 25), these plates defining a parallelepiped which contains the bag 1':

• the plate 22 is parallel to the long side of the bag 1 'and carries the other plates (23, 24, 25);
• the plate 23 is located on the side of the filling pipe 21, is therefore provided with a cutout at its upper part (FIG. 6c), and is simply fixed to the plate 22;
• the plate 24 is on the opposite side to the filling pipe 21 and is movably attached to the plate 22, for example by means of a hinge 34, to let the bag 1 empty;
• the plate 25 is on the lower side of the bag 1 ', and is movably attached to the plate 22, for example by means of a hinge 35, to let the bag 1' slide full.

In the embodiment shown in fig. 6, the plate 24 opens in pivoting around the hinge 34 in order to let the empty bag 1 pass. Alternatively, it is also possible to move the parallelepiped (22, 23, 24, 25) in its entirety from the rear in order to let the 1 'bag.

Once the bag 1 'is filled, the parallelepiped (22, 23, 24, 25) is moved (relative to pipe 21), first upwards until the bag 1 ′ rests on plate 25, then simultaneously (i) laterally so detach the bag 1 'from the filling pipe 21 and (ii) by pivoting so that the bag 1 'rests on the plates 25 and 22, as described in fig.7.

The plate 25 then pivots around the hinge 35 and lets slide the bag 1 'full, with the possible help of a top layer made of a fluoropolymer (e.g. polytetrafluoroethylene) on plate 25 and / or 22, and / or an air cushion created between the plate 25 and / or 22 and the bag 1 'by blowing air respectively through pipes 36 and 37.

The full bag 1 'slides directly out of the parallelepiped (22, 23, 24, 25) and is taken up by the means 38 (for example a conveyor belt) which prevail at a packaging installation and / or an installation shipping (not shown).

Although the invention is described above by means of specific modes of execution, it is obvious that these serve only as an illustration and that the invention is not necessarily limited thereto.

A wide variety of variants, alternative constructions and modifications to instructions and operating modes such as described above, which are understood by those skilled in the art in based on what is described above, are assumed to be part of the scope and protection of the present invention.

Claims (18)

1. Automatic filling machine for bags 1 made of plastic fitted with a valve 20, essentially comprising:

   support means 2, on which the bags 1 rest in the storage area;

   removal means 4 for drawing the bags 1 singly downwards between the support means 2;

   opening means 15 for opening the valve 20 and holding it open;

   filling means 21 for filling the bags 1 through the valve 20;

   means for transporting the bags 1 between successive handling operations;
   characterised in that

   the removal means comprise one or more means 4' firmly attached to a support 5 which is able to move vertically and is positioned in the middle of the support means 2, and other removal means 4'' movably attached to the support 5 on each of its sides in order to follow the deformation of the bags 1 when they are drawn singly downwards by the removal means 4;
   and in that the machine comprises:

   means 8 and 11 for aligning the bags 1 in a precise position;

   removal means 13 for gripping the bags 1 singly by the bottom to the side of the valve;

   pressure means 16 for making the bags 1 lose their memory of their folded shape; and

   means (22, 23, 24, 25) defining a parallelepiped shape comprising appropriate permanent or temporary openings for taking up the full bags again and delivering them in a constant orientation for the purpose of packing operations.
2. Automatic filling machine according to Claim 1, characterised in that the bags 1 are made of polyethylene.
3. Automatic filling machine according to Claim 2, characterised in that bags 1 are made of low-density polyethylene.
4. Automatic filling machine according to one of Claims 1 to 3, characterised in that the removal means 4 are suction cups.
5. Automatic filling machine according to one of Claims 1 to 4, characterised in that the bags 1 are positioned singly on an alignment plate 8 with the valve 20 facing upwards.
6. Automatic filling machine according to Claim 5, characterised in that the alignment plate 8 is provided with alignment means 11 for placing the bag 1' in a precise position.
7. Automatic filling machine according to one of Claims 1 to 6, characterised in that while the bag 1' is suspended from removal means 13, force is applied by means of the pressure means 16 in such a direction that each bag 1' loses the memory of its shape.
8. Automatic filling machine according to Claim 7, characterised in that the pressure means 16 consist of an intermittent blowing device.
9. Automatic filling machine according to one of Claims 1 to 8, characterised in that grips 14 hold the bag 1' suspended from removal means 13 while the opening means 15 open the valve 20.
10. Automatic filling machine according to one of Claims 1 to 9, characterised in that the removal means 13 are suction cups.
11. Automatic filling machine according to one of Claims 1 to 10, characterised in that the opening means 15 are formed by a part which presses on the valve 20 to hold it open.
12. Automatic filling machine according to one of Claims 1 to 11, characterised in that the filling means 21 for filling the bags 1 comprise a filling pipe 21 inserted into the valve 20.
13. Automatic filling machine according to one of Claims 1 to 12, characterised in that it also includes automatic means for preventing liquid from escaping through the filling pipe 21 in case the filling pipe 21 has not been inserted, or has not been inserted properly, into the valve of the bag 1'.
14. Automatic filling machine according to one of Claims 1 to 13, characterised in that the means (22, 23, 24, 25) for taking up the full bags 1 once again comprise plates.
15. Automatic filling machine according to one of Claims 1 to 14, characterised in that to take up the bags 1 again, the means (22, 23, 24, 25) are displaced upwards, laterally and by pivoting in order to detach the bag 1' from the filling pipe 21 and so that it rests on the lower plate 25 and on the plate 22 parallel to the main surfaces of the bag 1'.
16. Automatic filling machine according to Claim 15, characterised in that the lower plate 25 is attached in a movable and pivoting manner to enable the full bag 1' to slide.
17. Automatic filling machine according to Claim 16, characterised in that the sliding movement of the bag 1' is assisted by an upper layer of fluorinated polymer on the plate 25 and/or 22.
18. Automatic filling machine according to Claim 16, characterised in that the sliding movement of the bag 1' is assisted by a cushion of air between the bag 1' and the plate 25 and/or 22.

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