ES2733642T3 - Machine and method for making piles of folded sheets of paper - Google Patents

Abstract

Machine (1) for obtaining piles (50) of folded sheets of paper, or similar material, such as napkins or tissue, comprising: - a feeding means (121) for feeding a plurality of sheets (11) at along a predetermined feed direction (101, 101 ') - a table (20, 20'); - a star wheel unit (10, 10 ') mounted rotatably around a rotation axis (110,110'), said star wheel unit (10, 10 ') being arranged to receive said plurality of folded sheets and to place them in turn at said table (20, 20 '), in order to form a stack (50) of folded overlapping sheets in accordance with a first predetermined stack address; - a means of transport (30); - a transfer means that is arranged to transfer a complete stack (50) of folded sheets from said table (20, 20 ') to said transport means (30), said transport means (30) being arranged to transport said stack (50) of folded sheets along a transport direction (102); characterized in that said transfer means comprise a rotation means (60) arranged to rotate said stack (50) of folded sheets to transfer said stack (50) from said table (20, 20 ') to said transport means (30) , said rotation means (60) being configured to carry the axis of the stack (50) from said first predetermined stack address, when said formed stack (50) is located on said formation table (20, 20 '), a a second address of the predetermined stack, when said formed stack (50) is located in said transport means (30), wherein said transfer means is arranged to transfer said stack (50) of folded sheets from said table (20, 20 ') to said transport means (30) by means of a combination of movements comprising said rotation of the stack (50) of folded sheets of an angle established between 80 ° and 110 °, wherein said table is practically " comb "and comprises a plurality d and support parts (21) alternated to a plurality of empty spaces (22), said transfer means being configured to position themselves in said empty spaces to capture said stack (50) of folded sheets from said table (20, 20 ') and for transferring said battery (50) to said transport means (30), and wherein said rotating means (60) comprises a first grip part (61) and a second grip part (62) arranged to move towards / away from each of them between a grip configuration of said folded sheet piles (50) and a release configuration of said folded sheet piles (50), and vice versa.

Description

DESCRIPTION

Machine and method for making piles of folded sheets of paper

FIELD OF THE INVENTION

The present invention relates to the field of converting paper and similar products to obtain paper material in packages of folded sheets from continuous web material.

In particular, the invention relates to a machine for obtaining stacks of folded sheets of paper, or similar products.

In addition, the invention relates to a method of obtaining piles of folded sheets.

BACKGROUND OF THE INVENTION

As is well known, there are different types of machines and processes for obtaining piles of folded sheets of paper, or similar material, such as tissue paper, napkins or similar items.

One type of such machines has a transfer roller capable of rotating about an axis and peripherally provided with a predetermined number of curved blades. The blades extend starting from the roller in a direction opposite to the direction of rotation of the roller and impart to the roller a particular "star" shape from which the common name "star wheel" derives.

Between the two following curved blades, the transfer roller is, therefore, provided with a groove in which a feeding mechanism introduces, in turn, a sheet from among a plurality of sheets already folded and fed in rapid succession. The rotary transfer roller transfers the folded sheets fed to the grooves from a feed position to a discharge position. In the unloading position, a barrier is provided that causes the leaves to exit the respective grooves, such that the sheets accumulate on a formation table where a stack of overlapping sheets is formed. The different arrangement of the barrier can cause the products to be stacked along a vertical axis, one above the other, or along a horizontal axis, with the napkins resting on one edge one behind the other.

Once a predetermined height or length of the stack is reached, below the star wheel unit, the spacers work to separate the last sheet of the stack already finished from the first sheet of the successive stack. In the case of vertical stacking, once the separation of two sheets is carried out, the table is moved leaving the axis of the stack, which is in it, practically vertical upwards to place the stack on a conveyor belt. In case of horizontal stacking, the products can be released directly on a conveyor belt or other conveyor.

An example of this type of machine with stacking along a vertical axis is disclosed in EPl42l021. In this case, in order to increase the rate of obtaining, several coaxial star wheel units operating in parallel are provided. Each star wheel unit is associated with a conveyor belt dedicated to obtaining the stack of sheets. More specifically, each of the parallel conveyors, one for each star wheel unit and with a transport direction that is orthogonal to the axis of the star wheel unit, operates discontinuously, that is, during the transfer of the formed sheet stack, remains at rest, while once the stack is transferred, while the successive stack is being formed, it moves to a position to receive a successive stack.

In both cases, each stack of sheets must be transported forward to a strip placement station, or packing station, where the stack is pressed and rolled by a plastic film forming a package. During the movement between the point where the battery is released from the table on the conveyor belt and the packing station, the direction of transport of the battery is subject to numerous variations, including abrupt variations, which can damage the product and force to complicated technical solutions.

Therefore, in order to move the piles of sheets, for example, to feed them to a strip placement section, it is necessary to start from different adjacent lines of piles that are present in the conveyors described above that are parallel to each other, and take them to a configuration, where they are arranged in a column in a single row. To obtain this configuration, an additional conveyor belt arranged orthogonally to the conveyors described above is provided in which the line is obtained, as described in IT2006B000801 or IT2001RE00121.

An important and known drawback of sheet stacking machines of known type is low flexibility.

In fact, star wheel units of the known type are capable of obtaining both large batteries, also called "bulk" batteries, for sale to restaurants, coffee shops, communities or, alternatively, smaller batteries, also known as "flat batteries, for domestic or personal use. Therefore, in order to move from one procurement to another it is necessary to use two different machines.

In particular, in the case of "flat" piles, the folded sheets are stacked vertically and released overlapped on the formation table. Therefore, the growth of the stack occurs vertically to a predetermined height, quite low, and once its formation is completed, the table is removed from below the stack to release it on a conveyor belt.

In the case, on the other hand, of "bulk" products, the folded sheets are released with the pile that grows horizontally, until it reaches an important length, and they are taken to the band placement section in a horizontal direction, such as It was indicated previously in document ITBO2006A000801.

In both cases, several batteries, or packages, are formed that move from a configuration where they are adjacent creating a line of batteries, to a configuration where all are arranged in a row, so that they can feed the section of placement of bands at the same time. Said configuration change can be carried out by means of a pushing device that in turn pushes the piles of a line on a second conveyor belt, which is parallel to the first one, to be then fed to the band placement section. In order to feed the batteries to the band placement section, therefore, it is necessary to provide complicated transport devices and proceed at low speed.

As described above, in order to feed the stack to the band placement section, which is arranged downstream of the forming section, it is necessary to change the direction of the same stack, with the conveyor belts arranged orthogonally with each other. More specifically, the conveyor that is disposed downstream is adjacent to the conveyor that is disposed upstream, but leaving some inevitable space, or discontinuity, between them. Therefore, during the movement of the battery by means of the space between a conveyor belt and the other, it is possible to damage the product. Other prior art solutions are also disclosed in documents US3810344, FR2569171, US4884675, US2008 / 124209, DE7125313, US4102253 and US2003 / 021668.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide a machine for obtaining packages of folded sheets of paper, or similar products, which has a high production rate and, meanwhile, has a relatively small size.

It is also an object of the present invention to provide a machine for obtaining packages of folded sheets of paper, or similar products, that help to handle the piles formed by the various sections of the machine and, in particular, even to a placement section of bands, thus avoiding damaging the product along the route and structurally simplifying the machine.

Another object of the present invention is to provide a machine for obtaining packages of folded sheets of paper, or similar products, that can be operated continuously.

A further object of the present invention is to provide a machine for obtaining packages of folded sheets of paper, or similar products, which is highly flexible and, in particular, capable of manufacturing large packages, ie "bulk" type packages. "and smaller packages, ie" flat "packages, without major structural changes in the machine.

These and other objects are achieved by the machine for obtaining piles of folded sheets of paper, or similar material, such as napkins or tissue, in accordance with the present invention, comprising: - a feeding means for feeding a plurality of sheets along a predetermined feed direction;

- a star wheel unit mounted rotatably around a rotation axis, said star wheel unit being arranged to receive said plurality of folded sheets and to turn them on a table, in order to form a stack of sheets overlaps folded in accordance with a first predetermined stack address;

- a transfer means that is arranged to transfer a complete stack of folded sheets from said table to said transport means, said transport means being arranged to transport said stack of folded sheets along a transport direction;

whose main feature is that said transfer means comprises a rotation means that is arranged to rotate said stack of folded sheets to transfer said stack from said table to said transport means, said rotation means being configured to carry the axis of the stack from said first predetermined stack address, when said formed stack is located on said formation table, to a second predetermined stack address, when the formed stack is located in the transport means.

In particular, the first predetermined stack address can be selected from the group consisting of: - a practically horizontal address;

- a practically vertical direction;

- one direction at a predetermined angle with respect to a horizontal plane.

Advantageously, the second predetermined stack address is selected from the group consisting of:

- a practically vertical direction when the first predetermined stack address is practically horizontal;

- a practically horizontal direction when said preset battery address is practically vertical. In particular, the transfer means may further comprise a translation means that is arranged to transfer said stack of folded sheets from said table to said transport means.

Advantageously, there is provided a means to selectively actuate said translation means and said rotation means to transfer said stack of folded sheets from said table to said transport means, so that said stack of folded sheets is placed in said means of transport with a vertical or horizontal axis. In particular, during the obtaining of packages, or piles, of folded sheets of the "flat" type, the means for operating individually is arranged to actuate the means of translation. In this case, the "flat" stack of folded sheets has a practically vertical axis, both when it is located on the table and when it is located in the means of transport once it has been transferred to it. On the other hand, during obtaining packages, or piles, of folded sheets of the "bulk" type, the means for selectively actuating is arranged to actuate the rotating means. In this case, the "bulk" stack of folded sheets passes from a configuration with a practically vertical axis when it is arranged on the table to a configuration with a practically horizontal axis when it is located in the means of transport. In fact, if the "bulk" battery were transported with the free vertical axis, it could fall into pieces and, therefore, it would be necessary to press it. In this way, then, with the same stacking star wheel system, "flat" and "bulk" type products can be provided. There is, therefore, a high flexibility of obtaining between the two types of products and, in case flexible band machines are available, it is possible to change the production very quickly.

Advantageously, a band placement section is provided downstream of the star wheel unit in which said piles of folded sheets are applied a strip film, for example a film of plastic material, said placement section being of bands arranged along said transport direction, so that once arranged in said transport means, said piles of folded sheets move along a single direction of transport practically rectilinear until entering said band placement section .

The rotation means is arranged to rotate a stack of folded sheets at an angle set between 80 ° and 110 °, in particular equal to 90 °.

In particular, the transfer means can be adapted to transfer the stack of folded sheets from the table to the transport means by means of a combination of movements comprising the rotation described above and at least one translation.

In a preferable embodiment, the transport direction is practically parallel to the axis of rotation of said star wheel unit.

In particular, the table has practically "comb shape", which comprises a plurality of parts alternated to a plurality of empty spaces, said transfer means being configured to pass through said empty spaces to collect said stack of folded sheets from said table and transferring it to said means of transport.

Advantageously, the rotation means comprises a first and a second gripping part which, in use, are arranged on opposite sides with respect to said stack, in order to practically form a gripping device, said first and second parts being grips arranged to move towards / away from each other between a release configuration for said stack of folded sheets and a grip configuration for said stack of folded sheets, and vice versa.

In a preferable embodiment, the feeding means is arranged to feed a plurality of parallel rows of sheets to the star wheel unit, said star wheel unit comprising a plurality of coaxial star wheel elements, each being of which arranged to process a respective row of sheets of said plurality of rows of sheets disposing, in turn, said sheets on said table, in order to obtain a respective stack of folded sheets for each row along an axis oriented in a default stack address.

In particular, said plurality of star wheel units are configured to lift piles of sheets at the same time in the respective forming tables.

In this case, the transfer means and, in particular, the rotation means, can simultaneously transfer a plurality of folded sheet piles from said forming table to said transport means. This allows to obtain a high rate of obtaining without the need of complex technical solutions to handle the batteries from the point of release them in the means of transport to the section of placement of bands. In this case, the first and the second gripping part of the transfer means have a suitable length to simultaneously collect all the piles of sheets formed, for example, vertically, by said star wheel and place them, for example, horizontally on said means of transport.

In particular, the rotation means comprises a first plurality of gripping portions and a second plurality of gripping portions, said first and said second plurality of gripping portions arranged in use on opposite sides with respect to said plurality of stacks of sheets and being movable towards each other or between each other between a grip configuration for said folded sheet piles and a release configuration for said folded sheet piles, and vice versa.

Advantageously, the means of transport comprises a conveyor belt.

Alternatively, the transport means comprises a flat fixed support and a smooth surface where a plurality of mobile handling rods with respect to said flat support are arranged to slide said stack of folded sheets along said direction. Of transport. A combination of the two systems is also possible.

In particular, the transport means has an end arranged at a predetermined distance from the band placement section, such that a predetermined distance is present between the transport means and the band placement section.

Advantageously, the transport means is associated with a pushing means that is arranged to push said folded sheet piles to provide a predetermined acceleration to said folded sheet piles, said pushing being applied by said pushing means when said piles of sheets folded have to reach a correct position directly in the belt placement machine. More specifically, said thrust is sufficient to cause the displacement of said piles of sheets directly from said means of transport to said band placement section.

In a preferred embodiment, the distance between two successive handling rods is greater than the width of the stack of folded sheets of a predetermined step, so that this step is traveled by the transfer means for the time necessary for the means of transfer reach the path of the transport medium, discharge the battery onto the transport medium and avoid interference with the path of the incoming transport medium. This allows the means of transport to run continuously, that is, to avoid a stepped operation that would be necessary to avoid interference between the operation of the transfer means and the incoming transport means, and then increase the rate of obtaining the machine.

Advantageously, the table can be moved with respect to said star wheel unit, in order to follow the growth of said folded sheet stack.

An exemplary embodiment of the present invention comprises:

- a first star wheel unit arranged to receive from a first feeding means a first plurality of folded sheets which are in turn transported along a first feeding direction and overlap on a first table, in order to form a first stack or series of folded sheet piles;

- a second star wheel unit arranged to receive from a second feeding means a second plurality of folded sheets which are transported in turn along a second direction of feed and overlap on a second table, in order to form a second stack of folded sheets.

In particular, the transfer means is arranged to alternatively transfer said first and second sheet piles, or a series of folded sheet piles, onto said transport means.

In particular, the units of the first and second star wheels operate alternately, such that, while the first star wheel unit is creating a stack of sheets, the second star wheel unit is not supplied with folded sheets and the stack of folded sheets that have been formed by the latter are transferred by said means of transfer to said means of transport, and vice versa.

For example, the first and second star wheel units may be speculative with respect to a medium plane of the transport means.

Advantageously, flow above said, or each, star wheel unit the following are provided:

- a longitudinal cutting means, arranged to divide a paper tape, or similar material, into a plurality of strips;

- a folding means that is arranged to fold said paper strips in a predetermined configuration, in order to obtain said folded sheets that are fed to said star wheel unit along said feed direction,

- a cross-cutting means, arranged to cut said strips that fold into parts of strips in a length corresponding to an unfolded napkin, and

- a transverse folding means, for folding said strip parts into napkins.

In accordance with another aspect of the inventive idea, a method of obtaining piles of folded sheets of paper, or similar material, such as napkins, or tissue, comprises the steps of:

- feeding a plurality of folded sheets to a star wheel unit along a feed direction;

- orderly loading said plurality of folded sheets on a table by means of said star wheel unit, in order to form a stack of overlapping folded sheets;

- transferring said stack of folded sheets from said table to said transport means, which is arranged to transport said stack of folded sheets along a transport direction;

- handling said stack of folded sheets along a transport direction;

whose main feature is that said transfer step from said table to said transport means is performed by rotating a predetermined angle of said stack of folded sheets, said rotation means being configured to carry the axis of the stack from a first direction of the predetermined stack, when said formed stack is located on said formation table, to a second predetermined stack address, when said formed stack is located in said transport means.

Advantageously, downstream of said star wheel unit a band placement stage is provided in said folded sheet piles, said band placement stage being performed by a band placement section by applying a band film, by for example, a sheet of plastic material, around said stack of folded sheets.

In particular, the transport stage of said plurality of folded sheet piles to said band placement section is carried out along a single transport direction. Therefore, once transferred in said means of transport, the piles of folded sheets are transported to the band placement section along a single practically rectilinear direction.

Advantageously, the transfer stage comprises the additional steps of:

- laterally approaching said stack of folded sheets by a first and second grip parts movable towards / away from each other;

- in addition, bringing said first and second gripping portions together, in order to provide a compression of said stack of folded sheets;

- rotating said first and second gripping portions with said stack of folded sheets still compressed between them;

- away from each other said first and second gripping parts, to release said stack of folded sheets in said transport means.

In an exemplary embodiment of the present invention, the following may be provided:

- a first star wheel unit arranged to receive a predetermined number of folded sheets that are in turn transported along a first feed direction and overlapped on a first table, in order to form a first stack, or a series of folded sheet piles;

- a second star wheel unit arranged to receive a predetermined number of folded sheets that are transported in turn along a second feed direction and to overlap them in a second table, in order to form a second stack of sheets folded, in particular said second star wheel unit being in a mirror position to each other, that is, arranged in a symmetrical position with respect to said first star wheel unit.

Advantageously, between the feeding means and the first and second star wheel units, a deflecting means is arranged to alternately deflect the plurality of sheets towards the first, or towards the second star wheel unit.

In particular, any of the units of the first and second star wheels has a plurality of protruding parts, a groove arranged to receive a sheet of the plurality of sheets described above being obtained between the two following protruding portions.

Advantageously, the first star wheel unit is associated with a first insertion means arranged to place a sheet in a groove along a first insertion direction and the second star wheel unit is associated with a second means of introduction arranged to put a sheet in a groove along a second direction of introduction. In particular, the deflection means is adapted to alternately divert said plurality of sheets towards said first and towards said second introduction means.

Advantageously, the deflection means comprises a deflection element having at least one guide surface arranged alternately along the first direction of insertion of the blades into the first star wheel unit, or along the second direction of insertion of the blades in the second star wheel unit.

In an exemplary embodiment, the deflection means comprises a deflection element having a first and a second guide surface arranged to be alternately, and respectively, placed along the first direction of introduction. of the blades in the first star wheel unit and along the second direction of insertion of the blades in the second star wheel unit.

In particular, a drive rod can be provided operatively connected to said deflection means, said drive rod being arranged to selectively move said deflection means along the first, or second, direction of introduction, respectively.

In an exemplary embodiment, the deflection means comprises at least one deflection roller provided with:

- a first retention means for maintaining the sheets on a first angular part of the surface of said deflection roller, said first angular part ending in said first introduction means;

- a second retention means for maintaining said sheets, alternatively, to said first means for maintaining, in a second angular part of the surface of the deflection roller, the second angular part ending in the second insertion means.

In particular, the transfer means is arranged to alternately transfer said first and second stacks of sheets, or series of stacks, of folded sheets onto said means of transport.

In accordance with a further aspect, a transport means is provided comprising a transport unit for carrying a plurality of stacks, or packages, of sheets from a stacking section to a strip placement section, said transport unit comprising a pushing means that is arranged to apply, during the movement of said transport unit, an additional thrust on said folded sheet piles to provide a predetermined acceleration to said folded sheet piles, applying said extra thrust by said pushing means when said piles of folded sheets are approaching said band placement section. More specifically, the additional thrust described above is sufficient to cause movement of the stack of folded sheets towards said band placement section, at a predetermined position of said band placement section.

In this way, the stack of sheets, which without the pushing means would be left by the transport unit at the edge of said band placement section, and would require additional manipulation to reach a suitable band position, is carried by the pushing means to a position where the placement of bands can initiate further manipulation of the stack of sheets.

In particular, the pushing means applies a push on the piles of folded sheets by means of an elastic means loaded by a cam means disposed close to said strip placement section. In this way, no additional devices incorporated in the means of transport are necessary.

BRIEF DESCRIPTION OF THE DRAWINGS

An additional feature and the advantages of the machine for manufacturing packages of folded sheets of paper, or similar material, such as tissue paper, or napkins, according to the invention, will become more apparent with the following description of a mode of embodiment for example, non-limiting, with reference to the accompanying drawings, in which the similar reference characters designate equal or similar parts, in all figures from which:

- Figures 1 to 6 schematically show, in a side elevational view, a possible succession of stages by which the machine operates, in accordance with the invention, to obtain packages of folded sheets of paper, or similar material;

- Figures 7A and 7B schematically show a side elevational view of an exemplary embodiment of the machine shown in Figures 1 to 6 in two different operating stages;

- Figures 8A and 8B schematically show a side elevational view in perspective of a possible exemplary embodiment of the table and of the transfer means in some operational configurations;

- Figure 9 schematically shows a front elevational view in perspective of another exemplary embodiment of the machine of Figure 1;

- Figures 10 and 11 schematically show a side elevational perspective view of another exemplary embodiment of the star wheel machine of Figure 1;

- Figure 12 schematically shows a perspective view of the band placement section and the loading section of the machine of Figure 1;

- Figures 13 to 19 schematically show side elevational views of a possible exemplary embodiment of the transport means that can be associated with the machine of Figure 1 and of a thrust system at the exit of the transport unit .

- Figures 20 and 21 schematically show a side elevational view of two different working configurations of the machine, according to the invention, to obtain packages of folded sheets of paper, or similar material;

- Figures 22 to 27 show front elevation views of some possible exemplary embodiments of the deflection means adopted in the machine of Figure 20;

- Figure 28 schematically shows a side perspective view of the machine of Figure 20 provided with the transfer means for highlighting other structural features.

DESCRIPTION OF A FORM OF EMBODIMENT BY PREFERRED EXAMPLE

With reference to Figure 1, in a first exemplary embodiment, a paper conversion machine 1, according to the invention, comprises a star wheel unit 10 with at least one cylindrical body having a plurality of grooves 15, each of which is configured to receive a respective sheet 11 of a plurality of folded sheets 11. More specifically, the previously described plurality of folded sheets 11 are in turn carried, for example, between two transmission belts 200 and 201, along a feed direction 101, for example, a direction almost tangential to the star wheel unit 10. The latter rotates about a rotation axis 110, in the figure in a direction opposite to that of clockwise, and in turn unload sheets 11 from slots 15 to forming table 20, 120. More specifically, folded sheets are discharged to achieve a predetermined angular release position give, in order to form a stack of 50 sheets folded 11. More specifically, the release of sheets 11 on the table 20, 120 is performed, for example, by an extraction rod 18 arranged in the angular release position described above.

A cutting means may be provided upstream of the star wheel unit 10, for example, a cutting roller, not illustrated in the figures, arranged to longitudinally divide a sheet, or continuous web, of paper into a predetermined number of strips that are then folded according to a predetermined configuration by means of folding, also the latter not illustrated. The folded paper strips thus obtained can then be divided into parts of folded strips, by a transverse cut and then folded in order to form napkins. Said process is of known type and is therefore not illustrated in the figures.

While a stack is formed on one table 120, on the other table 20 the already formed stack 50 is carried towards an exit zone and then transferred by means of a transfer means 60, or 65, to said transport means 30. This The latter moves the stack 50 of folded sheets 11 along a transport direction 102 (Figure 9). The table 20, or 120, is provided movable towards / away from the star wheel unit 10, in order to follow the growth of the stack 50 of folded sheets and to eventually return to a position of minimum distance from the unit of Star wheel 10 once the rotation means 60 has profiled the battery 50.

In addition, each table, 20, 120, can function as a separating device, which separates the last sheet 11 from a formed stack 50, from the first sheet 11 'of the next stack 50'. More specifically, the next stack 50 'begins to grow on a table, on the table of Figure 120, while the formed stack 50 is transferred from the other table 20. Alternatively, a separating means can be provided and a single table, in a manner not described in detail, since it is of a known type in folded sheet pack transfer systems.

The transfer means may comprise translation means 65, advantageously shown only in Figure 1, which are arranged to move the stack 50 of folded sheets from the table 20 to the transport means 30, and may comprise a rotation means 60 arranged for transfer the stack 50 of the folded sheets 11 from the table 20 to the transport means 30 by means of a rotation (Figures 2 to 6).

Preferably, both translation means 65 and rotation means 60 are provided. In this case, the translation means 65 and the rotation means 60 are operated selectively, in particular by means for selectively operated not illustrated in the figures , to transfer the battery 50 from the table 20 to the transport means 30.

The rotation means 60 can be adapted to rotate the formed cell 50 from a position in which the shaft 55 is arranged along a practically vertical direction, when it is located on the table 20, or 120, to a position where the axis 55 is arranged along a practically horizontal direction, in the transport means 30 (Figures 1 to 6).

In an exemplary embodiment, shown schematically in Figures 7A and 7B, the stack 50 grows along a practically horizontal direction. In this case, the table 20, or 120, in order to follow the growth of the stack 50, are movable along a horizontal direction 220, in order to laterally contain the stack 50 which, during growth, it is supported by a flat support 255. In this case, the rotation means 60 is configured to cause the rotation of the stack 50 from a position where the axis 55 is arranged along a practically horizontal direction, when it is located in the table 20, or 120, to a position where the axis 55 is arranged along a practically vertical direction.

Thus, during the acquisition of packages, or piles, of folded sheets of the "flat" type, the translation means 65 is actuated, so that the axis 55 of the "flat" stack of folded sheets remains practically vertical also a once transferred to the transport means 30. On the other hand, during the acquisition of packages, or piles, of folded sheets of the "bulk" type, the rotating means 60 is operated, which carries the "bulk" battery 50 from a configuration with the axis 55 practically vertical, when it is arranged in the table 20, to a configuration with the axis 55 practically horizontal, when it is arranged in the transport means 30. Therefore, according to the type of product, "in bulk" or "flat", the corresponding transfer means is operated selectively. In the case of the "bulk" product, the step of transporting the battery 50 from the table 20 to the transport means 30 is carried out by means of a combination of movements, which comprises the previously described rotation of battery 50 at a predetermined, established angle. between about 80 ° and about 110 °, and at least one translation of the rotation means 60. The rotation of the batteries 50 made by the rotation means 60 prevents the batteries 50 from moving abruptly along the transport means 30 with a sharp change in direction, in particular for bringing the piles of sheets 50 to a strip placement section, or a packing section 80. During the handling of the "bulk" 50 batteries by the transport means 30, the axis 55 of the batteries 50 remains horizontal and is practically orthogonal to the transport direction 102 (Figure 9).

In a preferred exemplary embodiment, illustrated in detail in Figures 8A and 8B, the table 20 has a "comb" shape comprising a plurality of support portions 21 alternated to a plurality of empty spaces 22. Therefore, the transfer means 60, which are also comb-shaped, is arranged to coincide with the empty spaces 22 to collect the stack 50 of folded sheets and transfer it to the transport means 30.

The rotation means 60 may comprise a first grip part 61 and a second grip part 62 which, under conditions of use, are arranged on opposite sides with respect to the stack 50 and form practically a grip device. More specifically, the first and second gripping portions 61 and 62 of the gripping device are provided which can move toward / away from each other between a grip configuration of the stack 50 and a release configuration of the stack 50, and vice versa. In particular, in the release configuration, the gripping portions 61 and 62 can laterally approach the stack 50 and pass from an external position, in which the stack 50 is disposed between them (Figure 8A), and a compression configuration wherein the gripping portions 61 and 62 compress the battery 50 between them to transfer it to the transport means 30 by the rotation described above (Figure 8). After the battery 50 has been rotated, the gripping portions 61 and 62 move away from each other to release the battery 50 onto the transport means 30 (Figure 5).

According to an exemplary embodiment of the invention, in the case of packages, or batteries 50, of the "bulk" type, the rotation means 60 transfers the stack 50 of folded sheets from the table 20 to the transport means 30 through the following combination of movements:

- laterally approaching the gripping portions 61 and 62 to stack 50 folded sheets in order to move from an external position to the stack 50 (broken line in Figure 2) to a position where the stack 50 is disposed between them;

- approaching the first and second gripping portions 61 and 62, in order to provide a compression of the stack 50 of folded sheets between them (solid line of Figure 2);

- possible translation of the first and second gripping parts 61 and 62;

- turning the first and the second gripping part 61 and 62 with the stack 50 of folded sheets still compressed between them, in order to place them on the transport means 30 (Figure 3);

- possible translation of the first and second gripping parts 61 and 62 closed to place the battery 50 in the transport means 30;

- the first and second gripping parts 61 and 62 moving away from each other, in order to release the stack 50 of folded sheets on the transport means 30 (Figure 4).

In a particular exemplary embodiment of the invention, shown schematically in Figure 9, the machine 1 provides a first star wheel unit 10 and a second star wheel unit 10 '. More specifically, the first star wheel unit 10 is configured to receive a first plurality of folded sheets 11 which are in turn carried along a first feed direction 101 and to be superimposed on a first table 20, in order of forming a first stack or series of folded sheets 50, while the second star wheel unit 10 'is configured to receive a second plurality of folded sheets 11' which are in turn carried along a second direction of feeding 101 'and to superimpose them on a second table 20', in order to form a second stack 50 'of folded sheets. In this case, the rotation means 60 is configured to alternately transfer the piles 50 and 50 'of folded sheets from the respective tables 20 and 20' to the transport means 30. In particular, the first and second star wheel units 10 and 10 'work with phase shift with each other for a predetermined time. Therefore, when the stack 50 that is being formed on the table 20 has reached approximately half of its final height, the transfer means 60 drives the transport stack 50 'from the table 20' to the transportation means 30, and vice versa. Said technical solution allows, in particular, to significantly increase the production rate and at the same time limit the size of the machine 1. The star wheel units 10 and 10 'are mounted, specularly, in the middle plane 130 of the medium of transport 30 and have the respective rotation axes 110 and 110 'parallel to the transport direction 102.

As shown in the exemplary embodiment of Figures 10 and 11, the star wheel unit 10 may comprise a plurality of star wheel elements, for example, four coaxial star wheel elements 10a-10d . In this way, the star machine 10 can simultaneously make a plurality of piles 50 of folded sheets, for example, four piles 50a-50d, which grow at the same time in the respective forming tables 20a-20d. In this case, the rotating means 60 rotates the batteries 50a-50d at the same time during their transfer from the respective forming table 20a-20d to the transport means 30. In Figures 8A and 8B, the gripping parts 61 and 62 have been indicated with the same length equal to the width of a package or stack 50. However, the gripping portions 61 and 62 may have a suitable length to collect at the same time all sheet piles 50a-50d.

As shown schematically in Figure 12, downstream of the star wheel unit 10, a strip placement section 80 is provided where a strip film 81 is applied to the folded sheets 50, for example , of plastic material, whereby batteries with bands 85 are obtained.

The band placement section 80 is arranged along the transport direction 102 at the end of the transport means 30, which moves the batteries 50 from when they are discharged from the transfer means 60 to the band placement section 80 Said technical solution notably helps, with respect to the prior art machines, the handling operations of the batteries 50 through the machine 1 and to avoid possible damage to the product during handling by means of changes of direction and passage of One transport system to another.

The transport means 30 can comprise a flat support 35, which has a smooth low friction surface, where the piles 50 of folded sheets are arranged, and a plurality of manipulative rods 36 movable with respect to the flat support 35 to push the piles 50 of folded sheets along the transport direction 102 described above.

Once the band placement section 80 is reached, the piles of sheets 50 are transferred from the flat support 35 on a platform 82. The latter is provided movable along a direction practically orthogonal to the transport direction 102, ie , along a vertical direction, for example, by at least one actuator 83 to carry the stack 50 from a first height to a second height between which the strip film 81 extends. Thus, as is well known , the stack 50, when it passes from the first to the second height, meets the strip film 81 that is wound on the stack 50 obtaining a stack with bands, or package 85, which is transferred to an output conveyor belt 86 The means for placing bands in the folded sheet packages are indicated schematically, and are well known to a person skilled in this technique, and therefore, a detailed description is not necessary.

In the possible exemplary embodiment of Figures 13 to 19 there is provided a handling system formed by handling rods 36 that are integral to a carriage 150 displaced by a chain mechanism 40 along a loop comprising two practically horizontal parts 40a and 40b and two practically vertical parts 40c and 40d (Figure 13). In order to make a carriage 150 rotate in the connection between a horizontal part 40a, or 40b, and the next vertical part 40c, or 40d, the transport means 30 is arranged at a minimum distance from the band placement section 80, but sufficient, to enable a movement of the intermediate rod.

In particular, the transport means 30 ends at a minimum distance 200 from a lifting platform 81 of the band positioning section 80 and, therefore, between the transport means 30 and the lifting platform 81 there is a distance present 200 of minimum amplitude, sufficient to allow the passage of the rod 36. Also, here the section of band placement is described only schematically, since it is well known to one skilled in the art. The lifting platform 82 can be moved by an actuator 83, for example, a hydraulic actuator, along a practically vertical direction 122 between a first height (Figure 14) and a second height where a film of bands 81 is arranged which It is wrapped around stack 50 (Figure 12).

According to one aspect of the invention, each carriage 150 has an integral pushing element 38 to the handling bar 36. More specifically, at distance 200, the pushing element 38 is adapted to push the stacks of sheets 50 to provide a predetermined acceleration to the same batteries 50. The thrust described above is sufficient to make the folded sheet batteries 50 travel in the distance 200 and then pass directly from the transport means 30 to the platform 81 of the positioning section of bands 80. More specifically, the pushing device 38 is adapted to push the stack 50 to a practically centered position with respect to the strip film 82, in order to ensure that the band placement step is performed correctly.

Upon reaching a desired position, the pushing element 38 moves forward with respect to the carriage 150 driven by a mechanism comprising a fixed cam means 161 disposed in a predetermined position and cooperating with a mobile cam means 151 integrated in the carriage 150. More specifically, the mobile cam means 151 forms an integral part of a chain 45 mounted on the carriage 150. Until it reaches the position where the fixed cam means 161, the chain 45 and the mobile cam means are disposed 151 remain motionless (Figure 14). When the mobile cam means 151 reaches an interference with the fixed cam means 161, the chain 45 begins to move (Figure 15) resulting in a forward translation of the pushing element 38 and subsequently of the handling rod 36 which pushes battery 50 forward. This arrangement produces an acceleration of the battery 50 suitable for traveling the entire distance 200 (Figures 16 and 17). During a next step of tilting the carriage 150, the moving cam means 151 is disengaged from the fixed cam means 161 and the pushing element 38, by means of a spring that is loaded during the movement of the pushing means, is quickly removed until the return to the initial position (Figure 18) while the fixed cam means 161 reaches an interference with a moving cam means 151 'of a successive carriage 150'.

During the handling steps along the transport direction 102, the batteries 50 are contained laterally by the lateral retaining walls 32 and 33 (Figure 10).

As an alternative to that described above, the transport means 30 may comprise a conveyor belt, which is not illustrated in the figures.

An exemplary embodiment of the machine 1 for obtaining packages, or piles 50 of folded sheets 11 of paper, or similar material, such as napkins or tissues, is schematically illustrated in Figures 20 to 28. As shown, for example, in Figures 20 and 21, the machine 1 comprises a feeding means 121 for feeding a plurality of sheets 11 along a predetermined feeding direction 101 '.

In this case, the machine 1 comprises a first star wheel unit 10 which is rotatably mounted around a first axis of rotation 110 and a second star wheel unit 10 'rotatably mounted around a second axis of rotation 110' parallel to axis 110. In particular, each star wheel is configured to selectively receive the plurality of folded sheets 11 described above and place them in turn on a first table 20 and a second table 20 ', respectively. Thus, the first and second star wheel units 10 and 10 'form, respectively, a first and a second stack of overlapping folded sheets 50 and 50' (Figures 20 and 21).

More specifically, between the feeding means 121 and the star wheel units 10 and 10 ', a deflecting means 250 is arranged to alternately deflect the plurality of sheets 11 described above towards the first star wheel 10 (Figure 20), or towards the second star wheel 10 '(Figure 21). Like the first star wheel unit 10, the second star wheel 10 'also has a plurality of grooves 15', each of which is arranged to receive a sheet 11 from among the plurality of sheets described above. Each star wheel unit 10, or 10 ', is associated with the respective insertion means 210, or 210', for example, two conveyor belts 200 and 201, or 200 'and 201', arranged to place a sheet 11 in a respective slot 15, or 15 '. More specifically, the introduction means 200 supplies sheets 11 to the star wheel 10 along a first introduction direction 101, while the introduction means 210 'supplies sheets 11 to the star wheel 10' along a second direction of introduction 101 '.

As shown schematically in Figures 22 to 25, the deflection means 250 may comprise a deflection element 250 having at least one guide surface 251 arranged alternately along the first insertion direction 101 to feed the sheets 11 towards the first star wheel unit 10 (Figure 22), or along the second insertion direction 101 'to feed the leaves 11 towards the second star wheel unit 10' (Figure 23). For example, the deflection element 250 can be rotatably mounted around a rotation axis 255.

In a possible exemplary embodiment, schematically illustrated in Figures 24 and 25, the deflection means 250 may comprise a deflection element 250 ', for example practically wedge-shaped, having a first guide surface 251a and a second guide surface 251b which can be alternately, and respectively, placed along the first direction of introduction 101 to feed the star wheel 10 (Figure 24) and along the second direction of introduction 101 'to feed the 10 'star wheel (Figure 25).

In particular, a drive rod 70 operatively connected at one end to the deflection element 250 'and at the other end to a cam 75 is provided. Therefore, the drive rod 70 is disposed between an advanced position where the element deviation 250 'has the guide surface 251a arranged along the first direction of introduction 101 and therefore, the blades 11 are fed to the first star wheel unit 10 (Figure 24), and a withdrawal position , in which the deflection element 250 'with the guide surface 251b is moved along the introduction direction 101' and therefore, the blades 11 are fed to the star wheel unit 10 '(Figure 25 ). In particular, to bring the deflection element 250 'from the actual position of Figure 24 to the position of Figure 25, or vice versa, the handling rod 70 is subject to translation, withdrawing or advancing, and giving rise to rotation of the deflection element 250 'about a rotation axis 255' in a direction of rotation, or in the opposite direction.

In a further exemplary embodiment, schematically illustrated in Figures 26 and 27, the deflection means 250 comprises at least one deflection roller 25 having a first clamping means, for example a suction means not illustrated in the figure, and for example as described in WO2011015893 in the name of the same applicant, for storing sheets 11 on a first angular part 26 of its surface, that is, corresponding to the central angle a. More specifically, the first angular part 26 ending in the first insertion means 210 comprises, for example, a second deflection roller 35, which also has a retention means, for example, a suction means, and is arranged to transfer blades 11 from the deflection roller 25 towards the direction of introduction 101 to the star wheel 10.

The deflection roller 25 also comprises a second securing means, which is also not illustrated in the figures, to alternatively hold the sheets 11 on a second angular part 27 of the surface of said deflection roller 25, that is, corresponding to the central angle 13. More specifically, the second angular part 27 ends in the second insertion means 210 'comprising a third deflection roller 36, which also has a retention means, for example, a suction means, and lead sheets 11 arranged from the deflection roller 25 towards the direction of introduction 101 'of the star wheel 10'. Other configurations are possible to deflect the sheets by means of vacuum transfer rollers. For example, conveyor belts 200 and 200 'can find in direct contact with the vacuum roller 11.

Alternatively, the introduction means 200 and 200 'can be movable, in particular alternatively, towards / away from the deflection roller to transfer the sheets 11 from the deflection roller 25 to the star wheel 10, or 10' .

As shown schematically in Figure 28, in addition, there is provided a transport means 30 arranged to carry the batteries 50 along a transport direction 105 practically parallel to the rotation axes 110 and 110 'of the wheel units in star 10 and 10 '. In particular, the first and second star wheel units 10 and 10 'are arranged in symmetrical positions with respect to an axis of symmetry 130 orthogonal to the transport direction 105. In this way, the same rotation means 60 can be used to transfer the batteries 50 and 50 'from the respective training tables 20 and 20' to the transport means 30.

Claims (13)

1. Machine (1) for obtaining piles (50) of folded sheets of paper, or similar material, such as napkins or tissues, comprising: - a feeding means (121) for feeding a plurality of sheets (11) along a predetermined feeding direction (101, 101 ') - a table (20, 20 '); - a star wheel unit (10, 10 ') mounted rotatably around a rotation axis (110,110'), said star wheel unit (10, 10 ') being arranged to receive said plurality of folded sheets and to place them in turn at said table (20, 20 '), in order to form a stack (50) of folded overlapping sheets in accordance with a first predetermined stack address; - a means of transport (30); - a transfer means that is arranged to transfer a complete stack (50) of folded sheets from said table (20, 20 ') to said transport means (30), said transport means (30) being arranged to transport said stack (50) of folded sheets along a transport direction (102); characterized in that said transfer means comprise a rotation means (60) arranged to rotate said stack (50) of folded sheets to transfer said stack (50) from said table (20, 20 ') to said transport means (30) , said rotation means (60) being configured to carry the axis of the stack (50) from said first predetermined stack address, when said formed stack (50) is located on said formation table (20, 20 '), a a second address of the predetermined stack, when said formed stack (50) is located in said transport means (30), wherein said transfer means is arranged to transfer said stack (50) of folded sheets from said table (20, 20 ') to said transport means (30) by means of a combination of movements comprising said rotation of the stack (50) of folded sheets of an angle established between 80 ° and 110 °, wherein said table is practically "comb" shaped and comprises a plurality of support parts (21) alternated to a plurality of empty spaces (22), said transfer means being configured to position itself in said empty spaces to capture said stack ( 50) of folded sheets from said table (20, 20 ') and for transferring said stack (50) to said transport means (30), and wherein said rotation means (60) comprises a first gripping part (61) and a second grip portion (62) arranged to move toward / away from each of them between a grip configuration of said folded sheet piles (50) and a release configuration of said folded sheet piles (50), and vice versa. 2. Machine (1) according to claim 1, wherein said first predetermined stack address is selected from the group consisting of: - a practically horizontal direction; - a practically vertical direction; - one direction at a predetermined angle with respect to a horizontal plane, and where - the second default stack address is selected from the group consisting of: - a practically vertical direction when said first predetermined stack address is practically horizontal; - a practically horizontal direction when said predetermined address of the stack is practically vertical. 3. Machine (1) according to claim 1, wherein said transfer means further comprises a translation means which is arranged to transfer said stack (50) of folded sheets from said table (20) to said transport means (30), and wherein there is provided a means to selectively actuate said translation means and said rotation means (60) to transfer said stack (50) of folded sheets from said table (20) to said transport means (30) , with said means arranged to selectively actuate, said means of translation during the obtaining of stacks (50) of folded sheets of the "flat" type, so that a "flat" stack (50) of folded sheets remains practically with the vertical axis both on the table (20) and on said means of transport (30) once transferred, and said means for selectively actuating is arranged to actuate said means of rotation (60) during obtaining piles (50) of folded sheets of type "in bulk" of such man it was for carrying said "bulk" stack (50) of folded sheets from a configuration with a practically vertical axis when arranged in said table (20), to a configuration with practically horizontal axis when it is located in the means of transport (30). 4. Machine (1), according to claim 1, wherein downstream of said star wheel unit (10, 10 ') is provided a strip placement section (80) in which a strip film is applied ( 82) to said stack (50) of folded sheets, said band placement section (80) disposed along said transport direction (102), so that once arranged in said transport means (30), said stack (50) of folded sheets travel along a single transport direction (102) practically rectilinear until it enters said band placement section (80), in particular said transport direction (102) is practically parallel to said axis of rotation (110, 110 ') of said star wheel unit (10.10'). 5. Machine (1) according to claim 1, wherein said rotating means (60) is arranged to rotate the stack (50) of folded sheets at an angle equal to 90 °. Machine (1) according to claim 1, wherein said feeding means (121) is arranged to feed a plurality of parallel rows of sheets to said star wheel unit (10, 10 '), said unit comprising star wheel (10, 10 ') a plurality of coaxial star wheel elements each arranged to process a respective row of sheets of said plurality of rows of sheets which, in turn, arrange said sheets on said table (20, 20 ') in order to obtain a respective stack (50) of folded sheets for each row along an axis oriented in a predetermined stack direction. 7. Machine (1) according to claim 1, wherein said rotating means (60) is adapted to transfer, at the same time, said plurality of folded sheet piles (50) from said forming table (20, 20 ' ) to said means of transport (30). Machine (1) according to claim 1, wherein said transport means (30) has an end close to a band placement section (80), said transport means (30) being associated with a pushing means (38) which is arranged to push said folded sheet piles (50) to provide a predetermined acceleration to said folded sheet piles (50), said pushing means (38) being configured to apply said pushing pressure in said direction of transport (102) to move said stack (50) directly to said band placement section (80). Machine (1) according to claim 8, wherein said means of transport (30) comprises a flat support (35) wherein a plurality of handling rods (36), movable with respect to said flat support (35) , move said stack (50) of folded sheets along said transport direction (102), in particular the distance between two successive handling rods (36) that is greater than the width of said stack (50) of folded sheets , to make the means of transport (30) run continuously. 10. Machine (1) according to claim 1, comprising: - a first star wheel unit (10) arranged to receive from a first feeding means a first plurality of folded sheets which are in turn transported along a first feeding direction (101), and to overlap them on a first table (20), in order to form a first stack (50) of folded sheet piles (50); - a second star wheel unit (10 ') arranged to receive from a second feeding means a second plurality of folded sheets which are transported in turn along a second feed direction (101') and to overlap them on a second table (20 '), in order to form a second stack (50') of folded sheets, in particular said first and said second star wheel units (10,10 ') configured to operate in an alternate manner , such that, while said first star wheel unit (10) is creating a stack (50) of sheets, said second star wheel unit (10 ') is not supplied with folded sheets and the stack (50 ) of folded sheets that the latter has just formed is transferred by said transfer means to said transport means (30), and vice versa. 11. Machine (1) according to claim 1, comprising: - a first star wheel unit (10) mounted rotatably around a first axis of rotation (110), said first star wheel unit (10) being arranged to receive said plurality of folded sheets and to turn them on a first table (20), in order to provide a first stack (50) of overlapping folded sheets; - a second star wheel unit (10 ') mounted rotatably around a second axis of rotation (110') parallel to said first axis of rotation (110), said second star wheel unit (10 ') being arranged for receiving said plurality of folded sheets and to place them, in turn, on a second table (20 '), in order to provide a second stack (50') of overlapping folded sheets; wherein each star wheel unit (10, 10 ') between said first and said second star wheel unit (10, 10') has a plurality of protruding parts, obtaining a groove (15, 15 '), between two following protruding portions, being arranged to receive a sheet (11) of said plurality of sheets; and wherein between said feeding means and said first and second star wheel units (10, 10 ') there is provided a deflecting means (250, 250') to alternately divert said plurality of sheets towards said first, or said second star wheel unit (10, 10 '). 12. Machine (1) according to claim 11, wherein said first star wheel unit (10) is associated with a first introduction means (210), said first introduction means (210) being arranged to place a sheet (11) in a slot (15) along a first direction of introduction and said second star wheel unit (10 ') is associated with a second means of introduction (210'), said second means of introduction ( 210 ') arranged to place a sheet (11) in a groove (15') along a second direction of introduction, said deflecting means (250, 250 ') being arranged to alternately deflect said plurality of sheets (11) towards said first and towards said second introduction means (210, 210 '). 13. Method for obtaining piles (50, 50 ') of folded sheets of paper, or similar material, such as napkins or tissues, comprising the steps of: - feeding by means of a feeding means (121) a plurality of folded sheets (11) to a star wheel unit (10, 10 ') along a feed direction (101, 101'); - releasing said plurality of folded sheets on a table (20) by said star wheel unit (10, 10 '), in order to form a stack (50, 50') of overlapping folded sheets; - transferring by means of a transfer means said stack (50, 50 ') of folded sheets from said table (20) to a transport means (30), which is arranged to transport said stack (50, 50') of folded sheets to along a transport direction (102); - handling said stack (50, 50 ') of folded sheets along a transport direction (102); characterized in that said transfer stage from said table (20) to said transport means (30) is performed by a combination of movements comprising a rotation of said stack (50, 50 ') of ^folded sheets ^{of an angle set between 80 ° and 110 °, said rotation being by means of rotation (} 60 ⁾ configured to take the axis of the stack from a first predetermined stack direction, when said formed stack is located on said formation table (20), to a second direction of a predetermined battery, when said formed battery is located in said transport means (30); wherein said table (20) is practically "comb" shaped and comprises a plurality of support parts (21) alternated to a plurality of empty spaces (22), said transfer means being configured to position itself in said empty spaces (22 ) to collect said stack (50) of folded sheets from said table (20, 20 ') and to transfer said stack (50) to said means of transport (30), and wherein said means of rotation (60) comprises a first grip portion (61) and a second grip portion (62) arranged to move toward / away from each other between a grip configuration of said folded sheet piles (50) and a release configuration of said folded sheet piles (50 ), and vice versa.