EP3707090B1

EP3707090B1 - Apparatus for feeding and folding sheets and method

Info

Publication number: EP3707090B1
Application number: EP18815039.5A
Authority: EP
Inventors: Gabriele Brunetti
Original assignee: IMA Industria Macchine Automatiche SpA
Current assignee: IMA Industria Macchine Automatiche SpA
Priority date: 2017-11-07
Filing date: 2018-11-07
Publication date: 2024-04-03
Anticipated expiration: 2038-11-07
Also published as: EP3707090A1; CN111727162B; WO2019092767A1; CN111727162A

Description

FIELD OF THE INVENTION

The invention concerns the technical sector relating to automatic machines, and more precisely to automatic packaging machines.
In particular, the invention concerns a device for feeding sheets in sequence in a lying configuration to a device for folding said sheets, each of which consists, for example of an information sheet of a drug, to allow it to be inserted into a corresponding box, together with the relative drug.

BACKGROUND OF THE INVENTION

In techniques for packaging various products, for example drugs and cosmetic products, but not only, it is known to use equipment specifically provided to fold rectangular sheets containing instructions or advertising, until they are sized such as to allow them to be introduced into the box, together with the product.
In the state of the art, for example, folding apparatuses are known that have one or more folding seatings disposed in sequence on a folding path, which allow to make folds in sequential steps, in order to obtain sheets folded in a Z or double Z, or other similar shapes, usually rather complex.
Because of their peculiar construction characteristics, these folding apparatuses are complex, bulky, and require careful and precise adjustments and frequent maintenance interventions.
Moreover, the change in the format of the sheet or some fold characteristics, when provided, always requires components of the apparatus to be substantially disassembled and replaced. In this way there are several disadvantages due to the need to manage a considerable number of parts in the store, the long time required for format change operations, and the consequent high machine downtime, and therefore loss of productivity.
A more recent folding apparatus, described in the PCT International Patent Application published under n. WO2017068178 , in the name of IMA Industria Macchine Automatiche, comprises, like other previous apparatuses: a conditioning unit, intended to prepare each sheet for folding; a folding unit disposed downstream of the conditioning unit, intended to receive the sheet in a flat configuration and fold it into a tubular configuration; and an extractor unit, to pick up the sheet from the folding unit and direct it toward a pair of counter-rotating rollers belonging to the folding unit, which provide to compress the tube and transport it outside the folding apparatus.
In essence, a sheet to be folded is fed through an entrance guide to a substantially cylindrical conditioning seating, made in a containing body, in which there is a winding shaft, coaxial thereto. The latter has a longitudinal slit in which the arriving sheet is inserted.
A controlled rotation of the winding shaft forces the sheet to assume a circular configuration inside the conditioning seating.
The extractor unit comprises an extractor element mobile longitudinally with respect to the conditioning seating and driven by a belt transport, which slides along a groove made in the folding shaft and engages the sheet in a tubular configuration. The extractor element is made to translate toward the counter-rotating rollers of the folding unit and transports the sheet, removing it from the folding shaft, until the sheet itself engages the counter-rotating rollers and is drawn by them.
Although the folding apparatus described above represents a considerable step forward with respect to prior art folding apparatuses, especially in terms of constructive simplicity and production costs, in any case it has some disadvantages.
First of all, the maximum operating speed, and therefore the productivity of the machine, are conditioned by the fact that at least the folding shaft functions according to a start-stop principle, since it has to stop in order to receive the sheet, rotate to wrap it in a tube, and then stop again until the extractor element has completed its travel so as to take the tube as far as the folding unit.
In order to carry out another cycle it is also necessary for the extractor element to be repositioned in the starting position.
Another disadvantage is that the format change, and especially the change in width of the folded sheet, can be complex, and require the replacement of different parts of the apparatus. The adjustments and calibrations necessary to synchronize the different units can also be long and laborious.
Document US 4,221,373 dicloses the preamble of claim 1 and describes an apparatus for folding sheets of paper or suchlike, which comprises a store where the sheets are stacked, a feed mechanism which includes one or more suction heads in order to remove sheets in succession from the bottom of the pile of the store, a drum transporter, rotating around a fixed horizontal axis, on the periphery of which there are grippers able to open when the one or more suction heads deliver an initial portion of a sheet, and then to close over it in order to remove the sheet from the store and which winds around the periphery of the rotary drum transporter. The latter carries the sheet removed toward a closed belt-type conveyor, downstream of the rotating drum transporter, which conveys the sheet to a folding unit.
US 4,542,895 describes separator plates for the rotating feed segments of a sheet feeder.
Document US 2003/0001328 A1 describes an apparatus for separating sheet materials by means of a reciprocating disk-type separator.
There is therefore a need to perfect and make available a device for picking up and feeding sheets which overcomes at least one of the disadvantages of the state of the art.
Purpose of the present invention is therefore to propose a device for picking up and feeding sheets, for example, information sheets of a drug or a cosmetic product, to a device for folding said sheets, able to carry out the operations of picking up and feeding the sheet continuously, without it being necessary to stop and restart any component.
Another purpose of the invention is to provide a folding device which allows to obtain an adjustment of the calibrations necessary to obtain the removal of a single sheet in a simple and rapid manner, according to the characteristics of the sheet itself.
Another purpose of the invention is to propose a folding device which is simple to manufacture, with minimum requirements for calibration and maintenance, and low cost.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention

BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics of the invention will become clear from the following description of a preferential embodiment of the device for feeding sheets in sequence in a lying configuration to a device for folding said sheets, according to the claims and with the aid of the attached drawings, in which:

fig. 1 schematically shows a lateral view of the main members of the folding device which is the object of the invention, in a preferred embodiment;
fig. 2 schematically shows a front view of the device in fig. 1;
figs. 3, 4 and 5 schematically show the same view of the folding device shown in fig. 1, in subsequent operating steps of picking up and folding a sheet.

To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can conveniently be incorporated into other embodiments without further clarifications.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

We will now refer in detail to the various embodiments of the present invention, of which one or more examples are shown in the attached drawings. Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, the characteristics shown or described insomuch as they are part of one embodiment can be adopted on, or in association with, other embodiments to produce another embodiment. It is understood that the present invention shall include all such modifications and variants as comprised in the appended claims.
Before describing these embodiments, we must also clarify that the present description is not limited in its application to details of the construction and disposition of the components as described in the following description using the attached drawings. The present description can provide other embodiments and can be obtained or executed in various other ways. We must also clarify that the phraseology and terminology used here is for the purposes of description only, and cannot be considered as limitative.
In the above drawings, the reference number 100 is used to indicate an apparatus for feeding and folding a sheet 1 of paper or similar material, for example a prospectus illustrating a package for a drug, a cosmetic product or other. The apparatus 100 is intended to operate at the service of an automatic packaging machine to pick up sheets 1 in sequence in a lying configuration from a store 2, in which the sheets 1 are stacked in a pile 1a, to fold them in a predetermined folding pattern, and then to forward them to the packaging machine, in which suitable means for picking up the folded sheet and inserting it into a corresponding package, together with the product to be packaged, are conveniently provided.
The feeding and folding apparatus 100, in particular, comprises a device 50 for feeding sheets 1 in sequence, disposed in proximity to the store 2 and intended to pick up single sheets 1 from the base of the pile 1a, and a folding device 10 which is the object of the invention, disposed downstream of the feed device 50 with respect to a direction of feed of the sheets 1 to be folded indicated with an arrow W in the drawings cited.
The structure of the supply device 50 will be described in detail below. The folding device 10 comprises and is based on a closed circuit belt-type conveyor 11, mobile in said direction of feed W. The conveyor 11, as it advances, covers an operating path which extends (see fig. 1) between a zone A for picking up a sheet 1 in a lying configuration, in proximity to the feed device 50, and a zone E for expelling it in a folded configuration. Subsequently, the conveyor 11 travels a return path, inoperative, between the expulsion zone E and the pick-up zone A.
The sheets 1 are transported in the folding device 10 resting on an active upper face 11a of the conveyor 11, suitably supported and guided along the operating path, as will be described in more detail below.
The conveyor 11 is preferably but not restrictively made with a strip of yielding and inelastic elastomer material, of any type available on the market, and provided with suitable mechanical characteristics.
In correspondence with the pick-up zone A the conveyor 11 is supported by a first routing roller 12, mounted transverse to the direction of feed W, rotatable idly around its axis or motorized independently, depending on particular construction requirements.
Along the operating path, downstream of the first routing roller 12, the folding device provides a winding unit 13, intended to pick up each sheet 1 from the conveyor 11 and wind it in a tubular configuration.
For this purpose, the winding unit 13 comprises a fixed element 16 and a mobile element 17 mounted adjacent to each other.
The fixed element 16 is provided with a curvilinear section 16a, forming a sort of tube portion, and with a linear section 16b, which extends upstream with respect to the direction of feed W. The latter also has, at its end most upstream, a flap 16c which extends toward the conveyor 11, to constitute a guide for the sheet 1 arriving along the operating path.
The mobile element 17, in turn, consists of a curvilinear section 17a, which in turn forms a sort of tube portion, and of a linear section 17b, connected to alternative drive means of a substantially known type. The curvilinear section 17a faces the curvilinear section 16a of the fixed element 16 and has an opposite concavity, so as to form a winding seating 14 intended to receive the sheet 1 to take it into a tubular configuration.
The two curvilinear portions 16a, 17a, and at least the parts of the corresponding linear portions 16b, 17b in proximity to them, are also shaped like a comb, so as to alternate a series of apertures, parallel to each other, the function of which will become evident hereafter in the description.
The lower ends of the curvilinear sections 16a and 17a are distanced from each other, so as to form a slit 15 transverse with respect to the feed of the conveyor 11, disposed in proximity to the active face 11a thereof. In particular, the mobile element 17 can be driven in translation between an advanced winding position V (fig. 1), and a retracted exit position U (fig. 5), by drive means of a known type, to widen the slit 15 and facilitate the exit of the sheet 1 in a folded configuration.
The winding unit 13 also comprises a lead-in roller 18, idle around its axis, disposed in correspondence with the slit 15, on the opposite face of the conveyor 11. The lead-in roller 18 is intended to facilitate the entry of the sheet 1 into the winding seating 14.
Another motorized accompanying roller 19 is provided in the winding unit 13 in proximity to the winding seating 14, on the opposite side with respect to that of the slit 15, to facilitate the winding of the sheet 1 into a tube once it has entered the winding seating 14. For this purpose, the accompanying roller is made (see fig. 2) with a plurality of segments 19a, mounted in such a way that their outermost portion is slightly inserted into the winding seating 14, through the corresponding apertures made in the curvilinear sections 16a and 17a.
The accompanying roller 19 is mounted mobile with respect to the winding seating 14, and in particular with respect to the fixed element 16. To this purpose, it comprises known repositioning means, intended to allow it to be fed or retracted with respect to the axis of the winding seating 14. In this way the accompanying roller 14 allows to wind the sheets 1 to be folded into a tube with a different diameter. This characteristic is necessary and must be provided in order to vary the width of the sheets 1 in the folded configuration, depending on the width required for the subsequent insertion of the sheets 1 in the relative package.
The folding device 10 also comprises a folding unit 20, mounted in proximity to the winding unit 13 and intended to act on the sheet 1 in its tubular configuration, inside the winding seating 14, to compress it until it is taken to its flattened configuration, and then to convey it out of the winding seating 14 toward the belt-type conveyor 11.
The folding unit 20 comprises (fig. 1) a drive roller 21, mounted immediately downstream of the winding unit 13, in proximity to the curvilinear section 17a of the mobile element 17.
The drive roller 21 consists (see also fig. 2) of a plurality of equidistant small drive rollers 21a, which in turn are mounted on a shaft 21b to which drive members (not shown) are connected. The shaft 21b is driven by motor members (not shown), to rotate around its axis, by a predefined and adjustable angle, according to alternating directions of rotation.
The folding unit 20 also comprises folding means 22, consisting of a plurality of folding rollers 22a, mounted on corresponding cams 23, each one attached to a corresponding small drive roller 21a. The folding rollers 22a can oscillate, around the axis of the shaft 21b, as a consequence of the rotations of the latter, between an inactive position R (fig. 1) and a folding position P (fig. 5), and are intended to be inserted, in the path toward the folding position P, inside the winding seating 14, in order to compress the sheet 1 into a tubular configuration and facilitate its exit from the winding seating 14.
The folding device 10 comprises ejector means 30, disposed downstream of the winding unit 13 and of the folding unit 20 described above, with respect to the direction of feed W, in correspondence with the ejection zone E, and intended to remove from the conveyor 11 the sheet 1 in its folded configuration and expel it from the folding device 10, to deliver it to successive pick-up devices of the packaging machine, not shown.
The ejector means 30 comprise a pair of counter-rotating motorized rollers, respectively first 31 and second 32.
The first 31 and second 32 ejector rollers are disposed on opposite sides with respect to the conveyor 11, with the respective facing surfaces in contact with it. In this way, a sheet 1 coming from the winding unit 13 and the folding unit 20, and disposed resting on the conveyor 11, is pressed by the pair of ejector rollers 31, 32 and further flattened before being expelled from the folding device 10.
The latter also comprises other secondary components, and in particular: a motor roller 40, in turn driven by its own motor members (not shown), which in the embodiment shown is disposed in the lower part of the folding device 10, which engages the conveyor 11 and causes it to move; a tensioning roller 41, disposed between the drive roller 40 and the routing roller 12, which in turn engages the conveyor 11 to define its tension; and a second routing roller 42, disposed immediately upstream of the slit 15, and downstream of the flap 16c of the fixed element 16, to help the sheet 1 to advance along the operating path.
The feed device 50 separator members 60, intended to separate from the base of the pile 1a the external portion 1b of the sheet 1 to be removed (fig. 3), and pick-up members 70, intended to take the external portion 1b toward the conveyor 11 of the folding device 10, in particular, configured to take the external portion 1b of the sheet 1 into contact with the belt-type conveyor 11 at the entrance of the folding device 10. In particular, as explained in detail hereafter in the description, the pick-up members 70 are mobile, in particular in rotation, to be taken, when the separator members 60 are in the distanced position D, into the space between the flap of the external portion 1b of the sheet 1 and the rest of the pile 1a, increasing its separation.
In particular, preferred but not exclusive, the separator members 60 comprise a pair of gripping rollers 61, 62, parallel to each other and mounted on the same shaft, on which a suction block 65 is also mounted integral, provided with means, in particular a pair of suction channels 66, which lead to the upper face 67 of the suction block 65. The suction channels 66 are in turn maintained in depression by a suitable pump, not shown.
The separator members 60 are made mobile by means of corresponding drive members of a known type, between a close-up position S (shown by a solid line in figs. 1 and 3), in which the upper face 67 of the suction block 65 is located in proximity to the external portion 1b of the sheet 1 and the rollers 61, 62 are in contact with the active face 11a of the belt-type conveyor 11, and a distanced position D (shown by a line of dashes in the same drawings), in which neither the suction block 65, nor the rollers 61, 62 interfere with the movement of the sheet 1.
The pick-up members 70 comprise a pair of discoidal elements 71, 72, each mounted on a corresponding rotating shaft 73, 74 in proximity to the external edge of the pile 1a, at the height of its base. The discoidal elements 71, 72 are oriented so as to have a predefined angle, however relatively small, with respect to the lying plane of the sheets 1 in the pile 1a. This angle, in particular, is preferably comprised between 5° and 30°.
The discoidal elements 71, 72 are mounted eccentric on the respective shafts 73, 74. The latter are made to rotate, in a suitable phase relation with the movements of the separator members 60 described above, in opposite directions, and therefore in mutual counter-rotation.
An equal number of shaped arms 75, 76 are attached to the bottom face of the discoidal elements 71, 72 oriented in such a way as to result, depending on the rotation of the discoidal elements, facing each other or in phase opposition.
Hereafter, by way of example, we will describe a complete cycle of picking up, winding, folding and ejecting a sheet 1. The particular structure of the folding device 10 allows, however, to overlap two or more steps of the cycle, so as to improve the efficiency of the device and increase its productivity.
As shown in fig. 1, in an initial configuration, the belt-type conveyor 11 is made to move in the direction W. In the feed device 50, the discoidal elements 71, 72 are disposed in such a way that the respective shaped arms 75, 76 are both in the most distant position from the pile 1a of sheets 1; the separator members 60 are in their distanced position D. In the folding device 10, the winding unit 13 has the mobile element 17 in its winding position V, and the folding unit 20 has the folding means 22 in their inactive position R.
The separator members 60 are taken to the close-up position S, in which the gripping rollers 61, 62 come into contact with the conveyor 11, in correspondence with the first routing roller 12, and the suction block 65 moves with the external end of its upper face 67 into contact with the lower face of the sheet 1 disposed at the bottom of the pile 1a. The presence of a depression in the suction canals 66 generates a suction force which attracts the end flap of the sheet 1, until it adheres to the upper face 67. To this purpose the angulation of the upper face 67 with respect to the sheet 1 is significant, which is preferably - but not necessarily - between 3 and 30 degrees, and the suction pressure, which depends on the mechanical characteristics of the material of which the sheet 1 consists (its thickness, flexibility, etc.), which is established empirically, and which for materials commonly used is between 0.3 and 0.6 megapascals. In any case, the pressure is adjusted empirically so that the flap of the sheet 1 is attracted and adheres to the upper face 67, but the flap of the sheet 1 above it does not follow it. In this way the flap is separated from the rest of the pile 1a.
The separator members 60 are then made to retreat to the retracted position D, drawing with them the flap of the sheet 1 by the effect of the suction, and at the same time the discoidal elements 71, 72, and consequently the shaped arms 75, 76, are made to rotate so as to take first the external portion of the discoidal elements 71, 72, and subsequently the shaped arms 75, 76, into the space between the flap of the sheet 1 and the remainder of the pile 1a, increasing its separation. The rotational movement of the shaped arms 75, 76 generates an effect similar to a "screwing" of the sheet 1, separating it more and more from the pile la.
At a certain point, the flap of the sheet 1 detaches from the upper face 67 of the suction block 65, but in any case the sheet 1 continues to be separated from the pile 1a due to the effect of the action of the shaped arms 75, 76, until the flap comes into contact with the conveyor 11.
In the meantime, the separator members 60 are returned to the advanced position S, until the rollers 61, 62 come into contact with the flap of the sheet 1 on the conveyor 11, forcing its advance in the direction W.
The sheet 1 is then completely detached from the pile 1a and the store 2, continuing along the conveyor 11 until it is engaged by the second routing roller 42 (fig. 4).
Advantageously in this way, when the separator members 60 are returned to the advanced position S, it is possible in fact to temporally superimpose the feed step of a sheet that is already totally detached in the direction W, by the action of the rollers 61, 62 of the separator members 60, forcing the sheet 1 to be conveyed toward the folding device 10, with the step of first separation of another sheet 1 from the bottom of the pile 1a, by means of the suction effect, thanks to the proximity of the separator members 60 and of the respective suction block 35 with the bottom of the pile 1a in the advanced position S. The overall speed of the feed of the sheets 1 is therefore advantageously greatly increased.
Continuing along the operating path, the sheet 1 is then intercepted by the slit 15, and enters the winding seating 14 of the winding unit 13, where it begins to wind, sliding along the walls of the mobile element 17 first, and then along those of the fixed element 16.
The winding is facilitated by the action of the accompanying roller 19, until the sheet 1 is completely wound on itself, assuming a tubular configuration.
The folding unit 20 is then moved toward its folding position P (fig. 5). During this displacement the folding rollers 22a progressively push the tube consisting of the sheet 1 and compress it against the internal wall of the winding seating 14.
The mobile element 17 of the winding unit 13 is then made to translate backward to its exit position U, thereby increasing the width of the slit 15.
This causes the flattened sheet 1 to exit from the winding seating 14, and the sheet 1 is routed by the conveyor 11 until it is engaged by the lower part of the small drive rollers 21a of the folding unit 20. The latter cooperate with the conveyor 11 to advance the sheet 1 further, until it is engaged by the first 31 and second 32 ejector rollers, by which it is further flattened.
The sheet then exits from the folding device 10 ready to be packed, and is picked up by the pick-up means of the automatic packaging machine.

Claims

Apparatus (100) for feeding and folding a sheet (1) of paper or similar materials comprising:
- a feeding device (50) for feeding sheets in a lying configuration and in sequence,

- a folding device (10) for folding the sheets coming from the feeding device which comprises a belt-type conveyor (11) mobile in a direction of feed (W) of said sheets (1) to be folded, and

- at least one store (2) able to contain a plurality of said sheets (1) stacked in a pile (1a),

said feeding device (50) being arranged upstream of said folding device (10) with respect to said direction of feed (W) and comprising:
- separator members (60) intended to separate from a base of said pile (1a) an external portion (1b) of said sheet (1) to be removed, said separator members (60) being mobile between a distanced position (D), in which they do not interfere with said sheet (1), and a close-up position (S), in which they are in proximity to said external portion (1b) of said sheet (1) in order to remove the sheet (1) from the pile (1b),

- suction means (66) able to create a depression in correspondence with said external portion (1b) in order to attract it into contact with said separator members (60) so as to detach it from the base of said pile (1a), and

- pick-up members (70) operating in a suitable phase relationship with said separator members (60), and

the apparatus is characterized in that said pick-up members (70) are mobile to be taken, when the separator members (60) are in the distanced position (D), into a space between the flap of the external portion (1b) of the sheet (1) and the pile (1a), increasing the separation of the sheet (1) from the pile (1a) made by said separator members (60) and are configured to take said external portion (1b) of the sheet (1), which has been removed by the separator members (60) from the pile (1b), into contact with said belt-type conveyor (11) entering said folding device (10).
Apparatus (100) as in claim 1, characterized in that said separator members (60) comprise a pair of gripping rollers (61, 62), parallel to one another and mounted on a same shaft, which in said close-up position (S) are in contact with said belt-type conveyor (11), in correspondence with a first routing roller (12) of said folding device (10).
Apparatus (100) as in claim 1 or 2, characterized in that said separator members (60) also comprise a suction block (65) provided with said suction means (66), said suction block (65) being provided with an upper face (67) oriented at a suitable angle with respect to the sheets (11) of said pile (1a) when the suction block (65) is in said close-up position (S), into which said suction means (66) lead, in their turn comprising a pair of channels connected to a depression generating pump.
Apparatus (100) as in claim 3, characterized in that, when said suction block (65) is in said close-up position (S), said upper face (67) has an angle with respect to said pile (1a) comprised between 3 degrees and 30 degrees.
Apparatus (100) as in claim from 1 to 4, characterized in that said pick-up members (70) comprise a pair of discoidal elements (71, 72), each mounted eccentric on a corresponding rotating shaft (73, 74), disposed in proximity to the external edge of said pile (1a), approximately at the base thereof, and oriented so as to have a predefined angle with respect to the lying plane of said sheets (1) in said pile (1a); said shafts (73, 74) being made to mutually counter-rotate by their own motor means.
Apparatus (100) as in claim 5, characterized in that said lying angle is comprised between 5° and 30°.
Apparatus (100) as in claim 5 or 6, characterized in that an equal number of shaped arms (75, 76) are associated with said discoidal elements (71, 72), and are oriented so that, depending on the rotation of said discoidal elements (71, 72), they are counter-facing each other, or in phase opposition.
Method for feeding sheets, in a lying configuration and in sequence, using an apparatus (100) for feeding and folding a sheet (1) of paper or similar materials, comprising a feeding device (50), a folding device (10) comprising a belt-type conveyor (11) mobile in a direction of feed (W) of said sheets (1) to be folded, at least one store (2) able to contain a plurality of said sheets (1) stacked in a pile (1a), said feeding device (50) being disposed upstream of said folding device (10) with respect to said direction of feed (W), said method providing to:
- separate from the base of said pile (1a) the external portion (1b) of said sheet (1) to be removed by means of separator members (60),

- take said external portion (1b) into contact with said belt-type conveyor (11) entering said folding device (10) by means of pick-up members (70), operating in a suitable phase relation with said separator members (60);

said method providing to move said separator members (60) between a distanced position (D) in which they do not interfere with said sheet (1), and a close-up position (S), in which they are in contact with said external portion (1b) of said sheet (1a) in order to remove the sheet (1) from the pile (1b), and to move said pick-up members (70) in order to bring them, when said separator members (60) are in the distanced position (D), into a space between the external portion (1b) of the sheet (1) and the pile (1a), so as to increase the separation of the sheet (1) from the pile (1a) made by said separator members (60);

said method also providing to create a depression, by means of suction means (66) of said separator members (60), in correspondence with said external portion (1b), in order to attract it into contact with said separator members (60) so as to detach it from the base of said pile (1a).
Method as in claim 8, characterized in that it provides to use discoidal elements (71, 72), provided with shaped arms (75, 76), comprised in said pick-up members (70), and a pair of gripping rollers. (61, 62) and a suction block (65), provided with suction means (66), comprised in said separator members (60), said method providing that:
initially said discoidal elements (71, 72) are disposed in such a way that the respective shaped arms (75, 76) are both in the most distant position from the pile (1a) of sheets (1) and said separator members (60) are initially disposed in their distanced position (D),

subsequently, said separator members (60) are taken into the close-up position (S), in which the gripping rollers (61, 62) are taken into contact with the belt-type conveyor (11), in correspondence with a first routing roller (12) of said folding device (10), and the suction block (65) moves with the external end of its upper face (67) into contact with the lower face of the sheet (1) disposed at the bottom of the pile (1a), wherein the presence of a depression in the suction means (66) generates a suction force which attracts the end flap of the sheet (1), until it adheres to said upper face (67),

the separator members (60) are then made to move back to the distanced position (D), and at the same time the discoidal elements (71, 72), and consequently the shaped arms (75, 76), are made to rotate to take first the external portion of the discoidal elements (71, 72), and then the shaped arms (75, 76), into the space between the flap of the sheet (1) and the rest of the pile (1a), increasing the separation thereof, until the flap of the sheet (1) detaches from the upper face (67) of the suction block (65) and continues its separation from the pile (1a) due to the action of the shaped arms (75, 76), until the flap is taken into contact with the belt-type conveyor (11),

in the meantime the separator members (60) are returned to the advanced position (S), until the gripping rollers (61, 62) come into contact with the flap of the sheet (1) on the conveyor (11), forcing its advance in the direction of feed (W), so that the sheet (1) is completely detached from the pile (1a) and from the store (2), continuing along the belt-type conveyor (11) until it is engaged by a second routing roller (42) of said folding device (10).