ITPR20130037A1 - Stuffers - Google Patents

Description

DESCRIPTION

â € œBagging machineâ €

The present invention relates to a stuffing machine. Bagging machines of the type comprising:

- a forming device comprising an elongated body around which a sheet is wrapped and welded along two overlapping edges to obtain a tubular element (this welding is carried out by means of a vertical welding machine which is always fed);

-means of welding a lower edge of the tubular element to obtain a bag open at the top;

-a loading hopper which determines the introduction of a product inside the open bag;

-means of welding the upper flap of the filled bag.

This solution is not free from drawbacks due to the fact that the positioning of an open sheet around the forming device requires complex technical measures, as well as a considerable expenditure of energy to weld the overlapping edges necessary to obtain a tubular element. Furthermore, the need to weld the overlapping edges takes time, penalizing productivity.

There are also known bagging machines comprising a wound belt which is unwound, cut into pieces which are sequentially grasped and transported under the filler. The belt consists of a tubular element flattened so as to make two faces overlap. The transport phase under the filler is carried out by gripping hands that grasp one end of the piece, perform its overturning and at the same time, by means of special suction cups, mutually move the two overlapping faces away from each other to open the tubular piece.

Even this solution is not free from drawbacks mainly related to the complexity of the necessary structure (which translates into higher production and maintenance costs).

In this context, the technical task underlying the present invention is to improve the productivity of the stuffer while optimizing the components in order to minimize their costs.

The specified technical task and the specified purposes are substantially achieved by a stuffing machine comprising the technical characteristics set out in one or more of the appended claims.

Further characteristics and advantages of the present invention will become clearer from the indicative, and therefore non-limiting, description of a preferred but not exclusive embodiment of a stuffing machine, as illustrated in the accompanying drawings in which:

figure 1 shows a schematic view of a stuffing machine according to the present invention.

In the accompanying figures, the reference number 1 indicates a stuffing machine 1. The stuffing machine 1 comprises means 200 for forming a bag intended to receive a product to be stuffed. This product could be of any nature, preferably granular or powdery material.

The forming means 200 comprise a forming body 2 intended to pass inside a first tubular section 3 intended to give rise to said bag. This forming body 2 can also be called a forming tube. Said forming body 2 is also a retractor of two superimposed edges of said first tubular section 3. Advantageously, at one inlet end the forming body 2 has a diverging element 23, for example conical or frusto-conical. The bagging machine 1 in the preferred solution comprises means 8 for feeding the forming body 2 of a continuous band defined by a tubular with two faces overlapping and / or adhering to each other. Conveniently, the feeding means 8 comprise a reel 80 for accumulating said tape. Conveniently, the forming means 200 comprise means 6 for closing at least one edge of said first tubular section 3.

Advantageously, the stuffing machine 1 comprises means 4 for gripping the forming body 2 in turn comprising at least first and second means 41, 42 for supporting the forming body 21. The first support means 41 grip the forming body 2 upstream of the second support means 42 with respect to the direction of advancement of the first tubular section 3. The first support means 41 conveniently comprise a protrusion (for example a pin or a pin) which can be inserted into a corresponding hole present on the forming body 2. The same thing can be repeated for the second support means 42. The forming body 2 therefore remains suspended from the first and / or second support means 41, 42.

Advantageously, in a first configuration, the first support means 41 (and advantageously the second support means 42) perform their gripping action on the forming body 2. Conveniently in a second configuration the first support means 41 do not perform their gripping action on the forming body 2 to allow the passage of the first tubular section 3 (while the second support means 42 perform their gripping action on the forming body 2 in order to avoid falling).

In a third configuration, the second support means 42 perform their gripping action on the forming body 2 unlike the first support means 41. Conveniently, the first and second support means 41, 42 are fluid-dynamically operated. This improves operational reliability.

The forming body 2 has a preponderant direction 21 of axial development. Conveniently, the forming body 2 develops predominantly between the bottom and the top. Preferably, the forming body 2 develops vertically. Conveniently, an entrance area of the forming body 2 (for example the diverging element 23) is located at the top while an exit area from the forming body 2 is located at the bottom. Conveniently, the forming body 2 comprises baffles which can be moved transversely with respect to the predominant axial development direction 21 (these baffles advantageously move radially with respect to the axial development direction 21). In this way it is possible to adjust the widening of said first tubular section 3. This allows the forming body 2 to be adapted to different formats of the first tubular section 3. In this regard, in the preferred but non-limiting solution at least one of said septa is connected to a worm screw driven by an electric motor.

Conveniently, the stuffer 1 comprises cutting means 5 which separate said first tubular portion 3 from a continuous tubular. This continuous tubular is the belt that comes from the feeding means 8. The cutting means 5 therefore allow to adjust the length of the future bag. The cutting means 5 describe a trajectory that surrounds said forming body 2 to cut the first tubular portion 3. Conveniently, the cutting means 5 could comprise a mechanical blade (preferred solution), but could also comprise a nozzle that generates a liquid jet under pressure or a laser beam or other. The cutting means 5 preferably comprise a fifth wheel.

The cutting means 5 comprise a gear for moving a cutting element (blade or nozzle or other). Advantageously, at least said gear is made of Teflon. This allows to minimize the weight of the cutting means 5.

Conveniently, the stuffing machine 1 comprises a first vice 43. Conveniently, this first vice 43 cooperates with means 44 for dragging the first tubular section 3 to define tensioning means for the first tubular section 3. The driving means 44 comprise a belt designed to come into contact with a surface of the first tubular section 3 and which drags the first tubular section 3 by friction.

The cutting means 5 are interposed between the first vice 43 and the means 44 for dragging the first tubular section 3. In this way they are able to cut the first tubular section 3 by separating it from the remaining tubular. Similarly, the cutting means 5 are placed upstream of the first support means 41 with respect to the direction of advancement of the first tubular section 3 along said forming body 2.

Conveniently, the stuffer 1 can comprise auxiliary driving means 45 interposed between the first vice 43 and the cutting means 5. These auxiliary driving means 45 facilitate the advancement of the first tubular section 3.

The stuffer 1 comprises a second vice 46. This second vice 46 is placed downstream of the second support means 42. The second vice 46 has the task of keeping the bag integral with the forming body 2.

Conveniently, the forming body 2 comprises at a lower end a mouth 20 for introducing the product into the bag.

The stuffer 1 also comprises a filling tube 9 which is operatively interposed between a product accumulation tank 90 and the interior of said forming body 2 (and therefore the introduction mouth 20). The accumulation tank 90 can comprise an accumulation hopper 91 which flows into a dosing hopper 92 which allows to dose the quantity of product that flows into each bag. The filling tube 9 in a first operating mode is moved away from the forming body 2. In this way the first tubular section 3 can pass through a space interposed between the forming body 2 and the filling tube 9. In a second operating mode, the filling tube 9 flows into said forming body 2 (to transfer the product from the accumulation tank 90 to the forming body 2). The filling tube 9 advantageously comprises at least one sliding portion which moves away from or approaches the forming body 2. The forming body 2 comprises a lateral opening 93 into which, in the second operating mode, the filling tube 9 is partially inserted.

The second vice 46 is located downstream of said lateral opening 93.

Similarly, the second support means 42 are located downstream of said lateral opening 93.

Conveniently, the closing means 6 are located downstream of said mouth 20. In particular, the closing means 6 comprise welding means. Said welding means 6 weld two lower edges of said first tubular section 3 to obtain a bag open at the top (and advantageously also of two upper edges of the first tubular section 3 to close the bag filled with product).

In a particular constructive solution not shown, the stuffing machine 1 comprises a carousel located downstream of the forming body 2. This carousel can integrate the closing means 6. The carousel can include a plurality of stations in each of which a predetermined activity is carried out.

The object of the present invention is also a method of packaging a product in a bag. Conveniently, this method is implemented by a stuffing machine 1 comprising one or more of the characteristics described above. This method includes the steps of:

i) releasing the grip of said forming body 2 by first support means 41 while maintaining the grip of said forming body 2 by second support means 42 (suitably placed downstream of the first support means 41);

ii) to advance around the forming body 2 at least a first tubular portion 3 intended to define the bag. Conveniently, this first tubular section 3 comes from a continuous ribbon made available by a reel 80. This continuous ribbon has two superimposed layers, one 91.I1065.12.IT.1 Ing. Alberto MONELLI (Register no. 1342 B)

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on the other to define a flattened tubular. By advancing around the forming body 2, the first tubular portion 3 is spread apart and widens. In this phase, the first tubular section 3 annularly surrounds the forming body 2. The step of advancing around the forming body 2 at least a first tubular portion 3 comprises the steps of:

- making said first tubular section 3 pass between said forming body 2 and the first support means 41;

grasping said forming body 2 by means of the first support means 41 after the transit of at least the first tubular section 3. In this way, the forming body 2 is always supported at least either by the first or by the second support means 41, 42.

The method involves the step of cutting the first tubular section 3 separating it from a continuous tubular section placed upstream. As previously mentioned, the continuous tubular is the tubular that comes from the reel 80. The step of cutting the first tubular section 3 takes place when the first tubular section 3 is fitted onto and surrounds the forming body 2. The step of cutting the first tubular section 3 involves moving the cutting means 5 around the forming body 2.

The step of cutting the first tubular section 3 is simultaneous with the steps of: - holding said continuous tubular by means of a first vice 43;

- pulling said first tubular portion 3 by means of dragging means 44 in order to tension said first tubular portion 3 (the dragging means 44 push said first tubular portion 3 away from said first vice 43). The cutting means 5 are interposed between the first vice 43 and said dragging means 44.

The method further comprises the step of welding two flaps of a first end of the first tubular section 3 obtaining an open bag at a second end of the first tubular section 3. The step of welding the first end of the first tubular section takes place after the first end has reached downstream of the forming body 2 (in fact in this area the opposite edges can approach again as the forming body 2 is no longer interposed). The first end of the first tubular section 3 is the lower end of the first tubular section 3.

The method therefore provides for introducing the product into said open bag by making it pass through a mouth 20 of the forming body 2 which flows into said open bag. The step of introducing the product into said bag provides for the product to pass through said mouth 20 which lies at an outlet end of the forming body 2. The outlet end of the forming body 2 is located at a lower end of the forming body 2. The introduction mouth 20 is therefore turned downwards and the transit of the product takes place by gravity.

The forming body 2 develops predominantly between the top and the bottom; during the step of introducing the product into said open bag, the upper edges of the bag surround and are in contact with the forming body 2 to minimize the deposit of the product on the upper edges of the bag (this could compromise the subsequent sealing of the second end). The step of introducing the product into said open bag making it pass through a mouth 20 of the forming body 2 is preceded by the step of moving a filling tube 9 to insert one end of the filling tube 9 into said forming body 2 through an opening 93 (placing a product tank in communication with said mouth 20 of the forming body 2).

The step of making at least a first tubular section 3 advance around the forming body 2 involves passing the opening 93 with said first tubular section 3 so that the opening 93 places the inside and the outside of the body in communication 2 trainer (without being obstructed by the first section 3). After the sub-phase of re-grasping said forming body 2 by means of the first support means 41 and before the step of welding a first end of the first tubular section 3, the method provides for the following steps:

releasing said forming body 2 by the second support means 42;

- making the first tubular section 3 advance along the forming body 2, positioning the first end of the first tubular section 3 beyond an end region of the forming body 2 (in order to allow subsequent welding). In the preferred solution, the operation of the invention can be summarized as follows:

- the forming body 2 is supported by the first and second supporting means 41, 42 (the first and second supporting means 41, 42 comprise at least one or more pins which, entering the holes provided in the forming body 2, prevent the fall);

- the first vice 43 and the first support means 41 are opened;

- the auxiliary dragging means 45 drag the film downwards for the length necessary to form a new bag;

-the first vice 43 can be closed to allow the blocking of the film around the forming body 2 and its tensioning by the dragging means 44;

- the cutting means 5 (a fifth wheel) separate the first tubular section 3;

-the cut film is dragged downwards until the first support means 41 are released;

- the first support means 41 are clamped and the second support means 42 are opened;

- the cut film is made to descend until it brings the lower edges in correspondence with the closing means 6 (welding machines) which close the bag at the bottom;

- the bag is lowered until the lateral opening 93 on the forming body 2 is released, which allows the filling tube 9 to enter;

- the second vice 46 is closed which has the task of keeping the bag integral with the forming body 2 (in the meantime the product to be introduced into the bag has passed from the accumulation hopper 91 to the weighing hopper 92, in the quantity sufficient to fill a single sack);

- the filling tube 9 is inserted into the forming body 2 through the lateral opening 93;

- an outlet valve of the weighing hopper 92 is opened and the bag is filled;

- the filling tube 9 is withdrawn, the bag is released from the second vice 46 and rests full on a forklift truck;

- the upper extremity of the bag is welded and the bag is unloaded.

The invention thus conceived allows to achieve multiple advantages. First of all it allows to increase the productivity of the plant. In fact, the use of tubular elements is allowed which only require two welds at the ends and not a weld along a direction joining the two ends (as in the case in which the bag is made using a sheet). A further important advantage is linked to the fact that the divarication of the tubular element takes place by making a forming body pass inside the tubular element. This is possible thanks to the use of specific devices that allow you to alternately grasp and release the trainer body.

The invention thus conceived is susceptible of numerous modifications and variations, all falling within the scope of the inventive concept that characterizes it. Furthermore, all the details can be replaced by other technically equivalent elements. In practice, all the materials used, as well as the dimensions, can be any according to requirements.

Claims (10)

CLAIMS 1. Bagging machine comprising: i) forming means (200) for a bag intended to receive a product to be bagged, said forming means (200) comprising: - a forming body (2) intended to transit inside a first tubular section (3) intended to give rise to said bag; - means (6) for closing at least one edge of said first tubular section (3); ii) gripping means (4) acting on the forming body (2) and comprising at least first and second means (41, 42) for supporting the forming body (2); said first support means (41) being suitable for gripping the forming body (2) upstream of the second support means (42) with respect to the direction of advancement of the first tubular portion (3); characterized by the fact that in a first configuration the first support means (41) perform their gripping action on the forming body (2) while in a second configuration the first support means (41) do not perform their gripping action on the body (2) forming to allow the passage of the first tubular section (3) while the second supporting means (42) carry out their gripping action on the forming body (2). 2. Bagging machine according to claim 1, characterized by the fact that said forming body (2) has a predominant axial development direction (21) and comprises partitions which can be moved transversely with respect to the predominant axial development direction (21) to regulate the enlargement of said first tubular section (3). 3. Stuffing machine according to claim 1 or 2, characterized in that it comprises cutting means (5) which separate said first tubular section (3) from a continuous tubular section, the cutting means (5) being movable along a trajectory surrounding said forming body (2) for cutting said first portion (3). 4. Stuffing machine according to any one of the preceding claims, characterized in that said forming body (2) comprises at a lower end a mouth (20) for introducing the product into the bag. 5. Method of packaging a product in a bag comprising the steps of: i) releasing the grip of a forming body (2) by first support means (41) while maintaining the grip of said forming body (2) by second support means (42) located downstream of the first means (41) ) supporting; ii) to advance around the forming body (2) at least a first tubular section (3) intended to define the bag; the step of advancing around the forming body (2) at least the first tubular section (3) comprising the sub-phases of: - making said first tubular section (3) pass between said forming body (2) and the first support means (41); grasping said forming body (2) by means of the first support means (41) after the transit of at least the first tubular section (3); iii) welding two flaps of a first end of the first tubular section (3) obtaining a bag which is open at a second end of the first tubular section (3); iv) introducing the product into said open bag making it pass through a mouth (20) of the forming body (2) which flows into said open bag. 6. Method according to claim 5, characterized in that it comprises a step of cutting the first tubular section (3) separating it from a continuous tubular section upstream, the step of cutting the first tubular section (3) by means (5) cutting when the first tubular section (3) is fitted on and surrounds the former body (2); the step of cutting the first tubular section (3) involves moving the cutting means (5) along a trajectory that surrounds the forming body (2). 7. Method according to claim 6, characterized in that the step of cutting the first tubular section (3) is simultaneous with the steps of: holding said continuous tubular by means of a first vice (43); -pulling said first tubular portion (3) by means of at least dragging means (44) in order to tension said first tubular portion (3); the cutting means (5) being interposed between said first vice (43) and said dragging means (44). 8. Method according to any one of claims 5 to 7, characterized in that after the sub-phase of grasping said forming body (2) by means of the first support means (41) and before the phase of welding two edges of a first end of the first section (3) tubular the method involves the steps of: releasing said forming body (2) by the second support means (42); - making the first tubular section (3) advance along the forming body (2) by positioning the first end of the first tubular section (3) beyond an end region of the forming body (2). 9. Method according to any one of claims 5 to 8, characterized in that said forming body (2) develops predominantly between the top and the bottom; during the step of introducing the product into said open bag, the upper flaps of the bag surrounding and being in contact with the forming body (2) to minimize the deposit of the product on the upper flap. Method according to any one of claims 5 to 9, characterized in that the step of introducing the product into said open bag by making it pass through an opening in the forming body (2) is preceded by the step of moving a tube (9) to insert one end of the filling tube (9) into said forming body (2) by placing a reservoir (90) in communication with said mouth (20) of forming body (2) which flows into said open bag.