ES2949531T3 - Device for transporting flexible sheets - Google Patents

Abstract

Device (1) for transporting flexible sheets (2) that combines mobile support means (3) on which a sheet can be applied and which are adapted to move the sheet in a direction of travel; and suction means (5) for keeping the sheet applied against the support means, wherein the support means are configured so that a sheet applied against the support means adopts a warped shape in a plane transverse to the direction of travel. The procedure for transporting flexible sheets (2) in a direction of travel comprises warping the sheets in a plane transverse to the direction of travel.

Description

DESCRIPTION

Device for transporting flexible sheets

Technical sector of invention

The device for transporting flexible sheets of the present invention is one of those that allows the transport of flexible sheets used in the graphic arts sector or packaging industry, between different handling stations.

Background of the invention

In the graphic arts or packaging industry it is common to have to transport flexible sheets, for example between a feeding station and a printing station or between a rotary stacker and a stacking station. The rotary reamer formats materials initially rolled into a coil and, therefore, flexible, in the longitudinal direction, so that, after the sheets are cut transversely, they must be transported to be subsequently stacked or handled. These flexible sheets are made of materials such as paper, cardboard, plastic or similar, and particularly single-sided corrugated cardboard, which consists of two papers, one smooth or “linef' and one corrugated or “fluting”.

It is important that transport takes place in a controlled manner so that the position of the sheets is correct at the stacking station or other handling stations, such as a printing station, and that they do not curl up on each other during transport through the lack of rigidity in its longitudinal direction, which at the same time is the direction of transport, instead of remaining flat.

Devices such as the one described in patent document EP0363662 are known for transporting sheets. This document presents a device provided with a set of drag rollers combined with an air extractor to transport sufficiently rigid elements, such as double-sided or double/double corrugated cardboard sheets, in a suspended manner.

However, when the elements to be transported are not rigid enough, such as when these elements are flexible sheets, the device described in this document does not allow the transport of these flexible sheets at high speeds, since the air currents that are generated during the Transport of each flexible sheet can separate the sheet from the device, initially bending its front edge and finally separating the sheet from the device, causing the sheet to move out of the longitudinal direction of transport and remain arranged hindering the passage of other sheets. This situation requires that an operator has to intervene to remove the sheet that hinders the passage, making it necessary to stop the transport device, with the corresponding loss of time.

A solution to this problem would be to increase the force exerted by the air extractor in order to ensure that the sheets were more attached to the drive rollers. However, since the sheets are flexible, there would be a risk of damaging them during transport due to the action of the rollers on the sheet, and the sheets would stop when they rub against the plate through which the rollers protrude.

Document JP2008266020A describes a device according to the preamble of the attached claim 1. Said known device comprises two flat conveyor belts, placed at different inclinations, to retain portions of each flexible sheet during transport, forcing each sheet to bend between the conveyor belts and adopt a curved position. However, special care must be taken when positioning the conveyor belts, taking into account the speed, size and flexibility of the sheets, so as not to bend or damage the sheets during transport. Therefore, once the conveyor belts are in place, the size, flexibility and speed of the sheets to be transported cannot be easily changed. Additionally, since air currents generated between the conveyor belts while transporting each flexible sheet can separate the sheet from the device, the sheets must be transported at relatively low speeds.

US2005/242494A1 describes a device for transporting flat sheets comprising suction bands oriented obliquely with respect to the direction of transport.

Document JPS63196450 describes a mobile tray type sorter with a plurality of trays with a curved surface where sheets can be stored.

US2009/212484A1 describes a paper ejection device for ejecting sheets of paper from a machine to a paper receiving tray, to correct curling of the printed sheet during ejection.

US6131901A describes a suction conveyor for transporting stacked sheets.

US5006042A describes an apparatus for feeding cartons from a stack through a feed gate, comprising three parallel rows of friction wheels.

WO 2013/160399 A1 describes a device for transporting flexible sheets, which comprises:

- movable support means on which a sheet can be placed and which are adapted to move the sheet in a direction of travel; and

- suction means for keeping the sheet placed against the support means, wherein the mobile support means comprise axes that follow a curved path.

It is therefore an objective of the present invention to provide a device for transporting flexible sheets that allows flexible sheets to be transported at higher speeds without damaging them.

Explanation of the invention

The device for transporting flexible sheets of the present invention is one of those that combines mobile support means on which a sheet can be applied and which are adapted to move the sheet in a direction of movement, preferably straight and preferably horizontal; and suction means to keep the sheet applied against the support means.

According to the invention, the scope of which is only defined by the attached claims, the support means are configured so that a sheet applied against the support means adopts a warped shape in a plane transverse to the direction of travel, which may be for example ribbed or tile-shaped. Naturally, the warped shape can be both convex and concave, as well as being wavy, presenting convex sections and concave sections, advantageously allowing the sheet to move while maintaining the warped shape, thus increasing the resistance to bending of its front part and supporting higher accelerations and speeds. without separating from the device and without damaging itself.

In a variant embodiment, the warped shape has a curve whose ratio between the chord and the sagitta is less than 100, that is, 100 sagitta or less fit in the chord, so that the variation in the trajectory of the curve is sufficiently high. so that the sheet is sufficiently warped so that resistance to bending is achieved in the direction of transport.

In another variant of embodiment, the warped shape presents a curve whose ratio between the chord and the sagitta is greater than 10, that is, 10 sagittas or more fit on the chord, so that the variation in the trajectory of the curve is sufficiently low. so that the sheet can bend sufficiently but without being damaged.

Preferably, it is provided that the warped shape has a curve whose ratio between the chord and the sagitta is less than 100 and greater than 10, that is to say that between 10 and 100 sagitta fit in the rope, so that it confers good resistance to the sheets. to bend in the longitudinal direction of transport without damaging them.

In a variant of interest, the warped shape has a curve whose sagitta is greater than 20 millimeters, said shape being suitable for the transport of flexible cardboard sheets in a warped or grooved shape.

The mobile support means comprise drive axles parallel to each other, perpendicular to the direction of movement of the sheets and that follow a curved path in the plane transverse to the direction of movement of the sheets, said axles being provided with wheels. Said wheels determine a transport surface for the sheets through which the sheets can be transported when pushed by the wheels. Each drive axle can be independently driven by a motor, thus controlling the rotation speed of each axis so that the blades can be accelerated and braked by progressively increasing or reducing the rotation speed of consecutive axes as appropriate. This speed control can be controlled by a computer through which instructions are sent to the different motors that drive the axles, as well as other support means, such as a conveyor belt.

According to a variant of embodiment, the curved path followed by each drive axle in its plane transverse to the direction of travel of the blades is equal to the curve of the transport surface in that same transverse plane.

In a variant embodiment, the drive axles comprise straight sections whose ends are connected to rotation transmission parts coupled to both sides of the same wheel, thus allowing rotation to all the wheels of an axle, thus allowing the rotation to be transmitted to all wheels on the same axle.

In a variant of interest, the wheels are provided with lateral recesses for coupling the rotation transmission parts that allow the rotation of the section to be transmitted to the wheel and the wheel to transmit the rotation to the next section through its part. transmission.

In a variant embodiment, the profile of the rotation transmission parts and the wheel recesses is complementary, in a variant of interest the complementary profile being a complementary toothed wheel profile.

It is also disclosed that in a variant of embodiment the wheels are made of a more flexible material than the rotation transmission parts, thus allowing consecutive straight sections to vary the trajectory of the axle by slightly deforming the rotation transmission parts. wheel recesses. To achieve this effect, in an interesting variant the wheels are planned to be made of polyurethane or any other flexible material.

In a variant embodiment, the device also comprises means for ejecting defective sheets arranged between the axes, so that when said ejection means are operated by an operator, they push a defective sheet to remove it from the device. It is noted that upon slightly separating the sheet from the device, it will detach, allowing it to fall into a rejection container arranged under the ejection means. These ejection means will preferably be retractable, that is, they can be hidden inside the device and may include a pneumatic piston that, when activated, allows the sheet to be quickly pushed out of the device and the ejection means to be removed, thus removing only the defective sheet and preventing it from the rest of the sheets, which would not present defects, are expelled.

In another embodiment variant, the support means in the direction of travel comprise a conveyor belt, which allows better control of the sheets, especially for braking and precise positioning.

It is also disclosed that the device may comprise an acceleration section in which the mobile support means comprise drive axles parallel to each other, perpendicular to the direction of movement of sheets and that follow a curved path in the plane transverse to the direction. of movement of the sheets, said axles being provided with wheels, and a final section in which the support means comprise a conveyor belt, thus allowing that in the acceleration section the sheets can increase and decrease their speed according to the different actuations. drive axles keeping the sheets attached to the device and that in the final section the sheets can be better controlled, held more firmly and even released by deactivating the suction means in this final section, for example for stacking.

Even when the device described above comprises an acceleration section in which the mobile support means comprise drive axles parallel to each other, perpendicular to the direction of movement of the sheets, said axles being provided with wheels, and a final section in which the Support means comprise a conveyor belt, sufficient transport of the sheets could be achieved even if they were not warped, that is, they were transported flat, although in this case speeds and accelerations as high as when they are transported warped would not be supported. Naturally, the devices described above could also be considered in which the movable support means on which a sheet can be applied and which are adapted to move the sheet in a direction of displacement, were configured so that a sheet applied against the means support would adopt a flat shape in a plane transverse to the direction of travel, although speeds and accelerations as high as when transported warped would not be supported.

The device of the present invention therefore makes it possible to carry out a method for transporting flexible sheets that comprises applying a flexible sheet against mobile support means that are adapted to move the sheet in a direction of travel; and maintaining the sheet against the support means by means of suction means, so that the flexible sheet adopts a warped shape in a plane transverse to the direction of travel, that is, the procedure for transporting flexible sheets comprises warping the sheets in a plane transverse to the direction of travel, thus conferring greater resistance to the sheets bending on their front part during transport and allowing the sheets to be transported at higher speeds and accelerations.

Brief description of the drawings

To complement the description that is being made and in order to facilitate the understanding of the characteristics of the invention, this descriptive report is accompanied by a set of drawings in which, for illustrative and non-limiting purposes, the following has been represented:

Fig. 1a presents a bottom view of a variant embodiment of the device of the present invention;

Fig. 1b presents a sectional view in a transverse plane of the device of Fig. 1a;

Fig. 2 presents a diagram of the section in a transverse plane of the device;

Fig. 3 presents a sectional view in a transverse plane of another embodiment variant of the device of the present invention and a detail of the sectional view;

Fig. 4 presents a sectional view of the wheels of the device of Figs. 3a and 3b in correlative lace position;

Fig. 5 presents a perspective view of the wheels of Figs. 3a and 3b in correlative lace position; Fig. 6a presents a bottom view of another variant embodiment of the device of the present invention;

Fig. 6b presents a sectional view in a transverse plane of the device of Fig. 6a;

Fig. 6c presents a side view of the device of Fig. 6a;

Fig. 7 presents a system that incorporates the device of the present invention between a rotary rower and a stacking station;

Figs. 8a, 8b and 8c present the curvature of the sheets of the device of Fig. 7 in different sections; Fig. 9 presents another system that incorporates the device of the present invention between a stacking station and a printing station; and

Fig. 10 presents another system that incorporates the device of the present invention between a stacking station and a stack distribution station.

Detailed description of the drawings

The Figs. 1a and 1b present a bottom and section view of a first embodiment variant of the device 1 for transporting flexible sheets 2 of the present invention that has mobile support means 3 on which a sheet 2 can be applied and which are adapted to move the sheet in a direction of travel, to transport a sheet 2 or a succession of sheets 2 between different stations. In the illustrated manner and as will be seen later, the sheets 2 will preferably be transported suspended or hanging from the device 1, that is, arranged between the device 1 and the ground, allowing an operator to better visualize the transport of sheets from the ground.

As can be seen, the mobile support means 3 are wheels 8 arranged on axles 7 that allow the sheets 2 to be pushed during transport. Between the axles 7 and the sheets 2, a plate 19 is arranged, so that the wheels 8 pass through the plate 19 through windows 20 conveniently made in the plate 19 that allow the wheels 18 to protrude and push the sheets 2 in the direction of transport, in the manner illustrated in Fig. 1. It is planned that the same plate 19 has perforations 21 through which air can be sucked, so that suction means 5, which can be formed by one or more extractors 22 of air, allow the sheets 2 to be applied against the support means 3, that is, against the wheels 8. The plate 19 also has means for ejecting defective sheets 2 25, which when actuated, preferably by means of a piston tire that would be activated, for example, when an operator detected a defective sheet 2, protrude from the plate 18 causing the sheet 2 to be removed from the device 1.

As can be seen, the mobile support means 3 comprise drive axles 7 parallel to each other, perpendicular to the direction of movement of sheets 2 and that follow a curved path in the plane transverse to the direction of movement of the sheets 2, said axles provided with wheels 8 that determine the surface 4 for transporting sheets. It is anticipated that each axis 7 is driven by an independent motor and can rotate at different speeds, so that the transport speed of the sheets 2 can be varied, accelerating or braking the sheets 2 so that they can move at a higher or lower speed. and separate or join together without the increase in speed causing the sheets 2 to separate from the device 1 and block the passage of other sheets 2. In this way, it is also possible to sufficiently separate the sheets 2 between sheet handling stations. 2 in which the sheets 2 have to be spaced apart for correct processing.

As can be seen, the path that each drive axle 7 travels in its transverse plane to the direction of movement of the blades 2 is equal to the curve 6 of the transport surface in that same transverse plane, so that all the wheels 8 of the same axle 7, which will have the same radius, rotate at the same angular speed and will drive the sheet 2 at the same speed along the entire axis 7, conferring the curved shape 6 to the sheet 2.

Advantageously, the mobile support means 3 are configured so that the sheets 2 applied against the support means 3 adopt a warped or grooved shape in a plane transverse to the direction of movement, that is, they adopt a tile shape that gives the sheets 2 have greater resistance to bending on their front side when transported at high speeds between different stations, without damaging them. The sheets 2 will preferably maintain an essentially straight shape in a plane longitudinal to the direction of travel, so that they do not offer resistance to transport.

Therefore, it can be considered that the support means 3 determine a surface 4 for transporting sheets 2 which in turn has a warped or grooved shape, determining the section of this transport surface 4 in a plane transverse to the direction of displacement of the sheets 2 a curve 6, which can be both convex and concave or even a combination between convex and concave portions that form an undulation. Naturally, as a sheet 2 is arranged on the transport surface 4 by the effect of the suction means 5, it will take the same shape as the surface 4.

It is envisaged that the support means 3 may be discrete, such as the set of wheels 8 presented in Figs.

1a and 1b whose ends would determine the transport surface 4, as continuous, such as a conveyor belt 12 that allows the passage of air through it and which would determine the transport surface 4, such as a perforated belt or a net or mesh, for for example a metal mesh, as will be described later. As can also be seen in Figs. 1a and 1b, the perforations 21 in the plate 19 are distributed between the wheels 8 of the support means 3, thus ensuring that the force exerted by the suction means 5 is well distributed along the axis 7.

As can be seen in Fig. 1b, to ensure that the sheets adopt the warped shape, the means of Support 3 are arranged in such a way that the transport surface 4 determines a curve 6 which will be the shape that the sheets 2 will adopt during their transport. To ensure that the sheets 2 have sufficient resistance to bending frontally during transport, it is planned that the warped shape they adopt presents a curve 6 whose relationship between the chord c and the sagitta s is less than 100, that is, the distance of the chord c is 100 times or less the distance of the sagitta s, in other words, 100 sagitta or less fit on the string. As can be seen, this same curved shape 6 will be presented by both the support means 3, for example the axles 7 will follow the same curve 6, and the plate 19.

Although the sheets 2 are intended to be flexible, it is desirable that the sheets 2 do not adopt an excessively warped shape as this could be damaged. To avoid damage, especially when the sheets 2 are made of cardboard, it is advisable that the warped shape present a curve 6 whose ratio between the chord c and the sagitta s is greater than 10, that is, the distance of the chord c is 10 times or more the distance of the sagitta s, in other words, that 10 sagittas or more fit on the rope. Usually, the warped shape is expected to have a curve 6 whose sagitta s is greater than 20 millimeters, so that the device 1 is especially suitable for the transport of flexible sheets 2 of standard size.

Fig. 3 presents a cross-sectional view of a device 1 according to the present invention together with a detail of the device 1 in which it can be seen how the mobile support means 3 and the suction means 5 are combined. As can be seen Note, the drive axles 7 are mounted through supports 23 of the plate 19 and comprise straight sections 9 whose ends are connected to rotation transmission parts 10 coupled to both sides of the same wheel 8, the wheels 8 being provided with recesses 11 sides for coupling the rotation transmission parts 10, so that the axis 7 is curved. This curvature of the axle 7 is achieved by slightly pressure deforming the rotation transmission parts 10 and the wheels 8, which are intended to be more flexible than the rotation transmission parts 10, such as polyurethane. The rotation transmission parts 10 of the wheels are intended to be made of a more rigid material, such as polyethylene, polyoxymethylene, other plastics or even a metallic material or also any other material more rigid than the material of the recesses 11 of the wheels. the wheels 8. It is anticipated that the deformation exerted by the rotation transmission parts 10 to the wheels 8 will allow consecutive straight sections 9 to rotate by approximately 0.5 degrees, so that the rotation of the straight sections 9 is correctly transmitted to the wheels. 8. It is also provided that the rotation transmission parts 10 can fit into the lateral recesses 11 of the wheels 8 so that the rotation transmission parts 10 can move axially within each recess 11, alternately in the inward and outward direction. of the wheel 8, during the rotation of the axle 7. Naturally, it is anticipated that not the entire wheel 8 is made of this flexible material, but it could be sufficient if only the area of the recesses 11 were made of this flexible material.

It is foreseen that the suction means 5 incorporate an extractor 22 that exerts a suction effect through the perforations 21 of the plate 19 that allow the sheet 2 to be held against the support means 3. Naturally, it is also foreseen that the suction means 5 suction 5 are formed by different extractors, so that the suction can be controlled in different sections of the device 1, allowing, for example, the release of the sheet 2 at the end of its transport. It is anticipated that when the support means 3 are provided with wheels 8, and the plate 19 is provided with windows 20 through which the wheels 8 pass, it is possible that the plate 19 does not need perforations 21 if the suction exerted by the suction means 5 through the windows 20 were sufficient.

In the manner previously illustrated, it is achieved that the sheets 2 can be transported suspended, the support means 3 being mobile, such as wheels 8, which when rotating allow the sheets 2 to be moved along a transport surface 4, which when adopting a curved or tile shape, advantageously allowing the flexible sheets 2 to be moved at speeds higher than if the sheets 2 were flat, preventing them from separating from the device 1.

Fig. 4 presents a detailed view of the section of the wheels 8 of the device 1 of Fig. 3 in a correlative position of engagement with straight segments 9 of the axle 7. As can be seen, the ends of the straight sections 9 are provided with a threaded pin 14 that will pass through a hole 15 in each rotation transmission piece 10 in which a nut 13 is secured, so that the straight section 9 is firmly attached to the rotation transmission piece 10, thus achieving that When rotating the shaft 7, each straight section 9 rotates the rotation transmission parts 10 attached to its ends. The rotation transmission parts 10 are adapted to fit and be coupled in the lateral recesses 11 arranged on both sides of the same wheel 8, so that a straight section 9 that is driven by a motor transmits the rotation to the rest of the straight sections. 9 through the respective wheels 8. As described above, it is anticipated that the material around the lateral recesses 11 is flexible and allows successive straight sections 9 to be slightly inclined to each other as this material gives way around the recesses. laterals, but allowing the rotation to be correctly transmitted both to the wheel 8 and to the next straight section 9 of the axle 7. Naturally, it is foreseen that the fastening of the straight sections 9 to the rotation transmission parts 10 can be carried out in other alternative ways. that ensure the fixation of the straight sections 9 to the rotation transmission parts 10, such as a slotted shaft, a conical shaft or even an integrated shaft during the molding process of the rotation transmission part 10, among others.

As can be better seen in the perspective view presented in Fig. 5, the profile of the rotation transmission parts 10 and the recesses 11 of the wheels 8 is complementary, so that the rotation of the straight sections 9 can be transmitted to wheel 8 and it can transmit it to the next straight section 9 through the transmission parts of rotation 10. A particularly advantageous shape of the profile of the rotation transmission parts 10 and of the recesses 11 of the wheels 8 is a complementary toothed wheel profile, as illustrated in Fig. 5 and was also presented in the above Figures 3 and 4, although it was not evident from the section views presented. However, other complementary profiles that would allow the rotation to be correctly transmitted could be used, such as geometric shapes or other irregular shapes that allow the fit between the rotation transmission parts 10 and the recesses 11 of the wheels 8 and the transmission of the rotation of the axis 7. It is also highlighted that the profiles of the recesses 11 of the wheels 8 represented are the same and have a toothed wheel on both sides, which makes it possible to use identical rotation transmission parts 10, with one of the recesses 11 rotated with respect to the other.

Fig 6a presents another embodiment variant of the device 1 in which the support means 3 comprise a conveyor belt 12, such as a conveyor belt that allows the passage of air, so that the suction means 5 allow the sheet to remain applied against the conveyor belt 12 and can be moved on the transport surface 4, which in this case coincides with the conveyor belt 12. Unlike the previous variants in which the support means 3 were formed by different axes 7 that could rotate at different speeds, in the variant represented in Fig. 6a the conveyor belt 12 will advance at the same speed, it being not possible to accelerate sheets to separate them from each other using a single device 1. One option to solve this drawback would be to arrange different devices 1 in series, so that the conveyor belt 12 of each device 1 has a higher or lower speed than the previous one, depending on whether the sheets 2 are to be accelerated or slowed down. Naturally, it is also planned that the conveyor belt 12 is made up of different longitudinal belts, For example, 10 longitudinal belts of 40 mm each, provided with flexible, homokinetic couplings between them, so that they maintain the warped shape and the driving of all of them can be carried out by a single motor.

Naturally, the section view of the variant of Fig. 6a in which the support means 3 comprise a conveyor belt 12 will also present the curved section that allows the sheets 2 to be transported in the shape of a tile, so that it is allowed reach higher speeds without damaging the sheets 2, in the same way as previously described, the suction means 5 being adapted to exert a suction force that keeps the sheet 2 against the conveyor belt 12.

As illustrated in Fig. 6c, the conveyor belt 12, which can be a belt or any other transport surface that allows the passage of air, such as a mesh or a grate, can be driven by a single motor.

Naturally, it is foreseen that the support means 3 may have different sections, that is, that some sections of the support means 3 are formed by axles 7 provided with wheels 8, so that the speed of each axle 7 can be controlled in a manner independent to separate or join consecutive sheets 2, for example in an acceleration section T1 and other sections are formed by conveyor belt 12, so that although the speed of the conveyor belt 12 is the same, a single motor can be used to drive the tape, for example in a final section T2 as illustrated below.

Fig. 7 presents a system formed by a device 1 of the present invention for transporting sheets 2 between a rotary reamer 16 and a stacking station 17. The rotary reamer 16 is adapted to format materials initially wound on a reel and, therefore , flexible in the longitudinal direction by cutting sheets 2 from the material previously wound on the coil in its transverse direction.

The rotary rower 16 provides one by one the flexible sheets 2 to the device 1, which although initially they may remain flat on the support means 3, as indicated in section A illustrated in Fig. 8a, progressively the support means 3 will curve the sheet. flexible sheet 2, reaching a curvature as indicated in section B illustrated in Fig. 8b. until it adopts the curved tile shape indicated in section C and illustrated in Fig. 8c. This warped shape will allow it to be transported at high speed as described above, in order to, before reaching the stacking station 17 where it must be presented flat, return the sheet 2 from its curved transport position to the final flat position, adapted for storage in the stacking station 17. The system presented in Fig. 7 uses a rotary stacker 16 and a stacking station 17 of those known in the state of the art that provide and require straight sheets 2, so it is This transition between the flat and curved transport position of the sheets 2 is necessary. However, if the rotary rower 16 already provided the curved sheets 2, similarly to section C, the device 1 could directly pick up and transport the sheets 2 curved without needing to curve it progressively. The same would happen with the stacking station 17 if, for example, the sheets 2 adopted the flat shape simply by separating from the device 1. Advantageously, by adopting the sheets 2 the warped shape of a tile, they not only avoid separating from the device 1 during transport. , but also prevent the sheets, which are obtained from an initially rolled material, from having a tendency to roll up again.

As can be seen in Fig. 7, the device 1 has an acceleration section T1 in which the support means 3 will be formed by axles 7 provided with wheels 8, so that the speed of each axle 7 can be controlled in a controlled manner. independent to separate or join consecutive sheets 2, and a final section T2 formed by conveyor belt 12, so that, although the speed of the conveyor belt 12 is the same, a single motor can be used to drive the belt. Naturally, the support means 3 could also be formed entirely by axles 7 provided with wheels 8 or by one or more conveyor belts 12, as well as different combinations of sections. As illustrated, the sheets 2 are preferably transported suspended or hanging from the device 1, that is, arranged between the device 1 and the ground, not only allowing an operator to better visualize the transport of sheets from the ground, but also allowing the transport of sheets 2 such as single-sided corrugated cardboard with the wave open upwards, thus achieving their stacking with the open wave upwards, as they have to preferably be provided to the end customer.

Fig. 9 presents another system formed by a device 1 of the present invention for transporting sheets 2 between a stacking station 17, in which a set of flexible sheets 2 are stacked, and a printing station 18 in which the device 1 must transfer the sheets 2. As can be seen, the stacking station 17 will provide the flexible sheets 2 to the device one by one, which although initially they may remain flat on the support means 3, as indicated in section A illustrated above in Fig. 8a, progressively the support means 3 will curve the flexible sheet 2, presenting a curvature as indicated in section B illustrated above in Fig. 8b. until it adopts the curved tile shape indicated in section C and illustrated previously in Fig. 8c, which will allow its transport at high speed as described above, stopping, before reaching the printing station 18 in which must be presented flat, returning the sheet from its curved transport position to the final flat position, adapted for insertion into the printing station. The system presented in Fig. 7 uses a stacking station 17 and a printing station 18 of those known in the state of the art that provide and require straight sheets 2, so this transition between the flat and curved position is necessary. Of transport. However, if the feeding station already provided the curved sheets 2, similarly to section C, the device 1 could directly pick up and transport the curved sheets 2 without requiring progressive bending. The same would happen with printing station 18 if it accepted folded sheets 2. In this way, it is possible to transport sheets 2 by applying a flexible sheet 2 against the mobile support means 3 adapted to move the sheet 2 in a direction of displacement and keeping the sheet 2 against the support means 3 by means of suction means 5. , so that the flexible sheet adopts the warped shape in a plane transverse to the direction of travel. Naturally, it is envisaged that the device 1 of the present invention can be used to transport sheets 2 between many other types of stations, such as laminating stations, among others.

Fig. 10 again presents the device 1 of the present invention, now between a stacking station 17 and a stack distribution station 24, allowing the sheets 2 of the stacking station 17 to be transported in the manner previously described but now releasing the sheets 2 after passing an acceleration section T1 and upon reaching a final section T2, grouping the sheets two by two or even in larger groups in order to be able to redistribute the sheets 2 that were initially stacked in the stacking station 17 in different piles at the stack distribution station 24, so that the size of each stack is smaller and the sheets can subsequently be moved more easily. In this way, for example as illustrated in Fig. 10, the device 1 will wait for three sheets 2 to reach the final section T2 of the device 1 and then the suction means 5 of the final section T2 will be deactivated and/or activated. pushing means, such as projections projecting from the transport surface 4, to separate the sheets 2 from the transport surface 4, allowing the sheets 2 to be stacked each in a stack of the stack distribution station 24 Naturally, the device would also allow transportation between a rotary rower 16 and a battery distribution station 24, in an analogous manner.

Although in the previously represented variants of the device 1 the flexible sheets 2 are transported suspended, the support means 3 being above the sheets 2, it is also provided that in other embodiment variants the flexible sheets 2 are above the support means. support 3, for example when the device is mounted directly on the ground. Advantageously, when the flexible sheets 2 are transported suspended, their observation by an operator is facilitated, so that defective sheets 2 can be visually detected. These defective sheets 2 could be removed from the device 1 by the operator activating sheet ejection means 25, such as a pneumatic piston that protruded from the support means 3, so that the defective sheet 2 could be detached from the device 1. device 1 and fall into a rejection container arranged below the pneumatic piston. Also if it were not necessary for the speed or acceleration of the sheets 2 to be high, devices similar to those previously represented could even be contemplated in which the sheets 2 were transported flat, that is, the support means determined a transport plane. plane and were configured so that a sheet applied against the support means adopted a planar shape with respect to a plane transverse to the direction of travel.

Claims (15)

1. Device (1) for transporting flexible sheets (2) that comprises: - mobile support means (3) on which a sheet can be applied and which are adapted to move the sheet in a direction of movement; and - suction means (5) to keep the sheet applied against the support means; wherein the support means are configured so that a sheet applied against the support means adopts a warped shape in a plane transverse to the direction of travel; the device being characterized in that the mobile support means comprise driving axes (7) parallel to each other, perpendicular to the direction of movement of the sheets, and which follow a curved path in the plane transverse to the direction of movement of the sheets, said axles provided with wheels (8). 2. Device (1) according to the previous claim, characterized in that the warped shape presents a curve whose ratio between the chord (c) and the sagitta (s) is less than 100. 3. Device (1) according to any one of the preceding claims, characterized in that the warped shape presents a curve whose ratio between the chord (c) and the sagitta (s) is greater than 10. 4. Device (1) according to any one of the preceding claims, characterized in that the warped shape presents a curve whose sagitta (s) is greater than 20 millimeters. 5. Device (1) according to any one of the preceding claims, characterized in that the curved path followed by each driving axle (7) in its plane transverse to the direction of movement of the blades is equal to the curve (6) of the surface. transportation in that same transverse plane. 6. Device (1) according to any one of the preceding claims, characterized in that the drive axles (7) comprise straight sections (9) whose ends are connected to rotation transmission parts (10) coupled to both sides of the same wheel. (8). 7. Device (1) according to the preceding claim, characterized in that the wheels (8) are provided with lateral recesses (11) for coupling the rotation transmission parts (10). 8. Device (1) according to the previous claim, characterized in that the profile of the rotation transmission parts (10) and the recesses (11) of the wheels (8) is complementary. 9. Device (1) according to the preceding claim, characterized in that the profile of the rotation transmission parts (10) and the recesses (11) of the wheels (8) is a complementary toothed wheel profile. 10. Device (1) according to any one of claims 6 to 9, characterized in that the wheels (8) are made of a more flexible material than the rotation transmission parts (10). 11. Device (1) according to the previous claim, characterized in that the wheels (8) are made of polyurethane. 12. Device (1) according to any one of the preceding claims, characterized in that it also comprises means for ejecting sheets (2) (25) arranged between the axes (7). 13. Device (1) according to the preceding claim, characterized in that the ejection means (25) comprise a pneumatic piston. 14. Device (1) according to any one of the preceding claims, characterized in that the support means (3) in the direction of travel comprise a conveyor belt (12). 15. Device (1) according to any one of the preceding claims, characterized in that it comprises an acceleration section (T1) in which the mobile support means (3) comprise driving axles (7) parallel to each other, perpendicular to the direction of movement of sheets (2) and that follow a curved path in the plane transverse to the direction of movement of the sheets, said axles being provided with wheels (8) and a final section (T2) in which the support means comprise a conveyor belt (12).