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 folding a sheet of paper, for example 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 devices 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 International patent application PCT 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 manner, 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.

Purpose of the present invention is therefore to propose a device for folding sheets, for example, information sheets of a drug or a cosmetic product, able to carry out the operations of folding and extracting the sheet continuously, without it being necessary to stop and restart any component.

Another purpose of the invention is to propose a folding device which allows to make the format change of the fold or the sizes of the sheet in a simple and rapid manner.

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.

These and other purposes are fully obtained by means of a device for folding a sheet of paper or similar materials, which belongs to an apparatus for feeding and folding the sheet. The apparatus comprises a store, able to contain a plurality of said sheets stacked in a pile, a device for feeding sheets in sequence, and the folding device, disposed downstream of the feed device with respect to a direction of feed of the sheets to be folded.

SUMMARY OF THE INVENTION

The folding device comprises: a closed circuit belt-type conveyor able to house, resting on it, a sequence of the sheets to be folded, the conveyor being mobile in the direction of feed and extending along an operating path; a first routing roller, disposed transversely with respect to the direction of feed, which engages the conveyor in proximity to the feed device; a winding unit, forming a winding seating able to house the sheet, and a slit that faces the conveyor to allow the entry of the sheet into the winding seating; a folding unit, comprising folding means, mobile between an inactive position and a folding position, and intended to be inserted inside the winding seating, in order to compress the sheet into a tubular configuration and facilitate its exit from the seating; ejector means, disposed downstream of the winding unit and intended to pick up the folded sheet from the conveyer and expel it from the folding device.

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 folding a sheet of paper or similar materials, 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.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

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 sequentially pick up sheets 1 in a lying configuration from a store 2, in which the sheets 1 are stacked in a pile la, 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 la, 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. With regard to the present invention, 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 1 1 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 1 1a of the conveyor 1 1, suitably supported and guided along the operating path, as will be described in more detail below.

The conveyor 1 1 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 the embodiment of the invention shown, preferred but not exclusive, 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 1 1, disposed in proximity to the active face 1 la 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 in a tube manner 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.

According to the invention, 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 in a tube manner 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 1 1.

In the embodiment described and shown, 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.

In particular, in the embodiment 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 1 1, 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 to which reference has been previously made comprises separator members 60, intended to separate from the base of the pile la the external portion lb of the sheet 1 to be removed (fig. 3), and pick-up members 70, intended to take the external portion lb toward the conveyor 11 of the folding device 10.

In particular, 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 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 lb of the sheet 1 and the rollers 61, 62 are in contact with the active face 1 1a 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 la, 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 la. 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 1 1 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 la 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 1 1, 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 la. 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.

The separator members 60 are then made to retreat to the retracted 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 subsequently the shaped arms, into the space between the flap of the sheet 1 and the rest of the pile la, increasing its separation.

At a certain point, the flap of sheet 1 detaches from the upper face 67 of the suction block 65, which in any case continues to be separated from the pile la 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 1 1 , forcing its advance in the direction W.

The sheet 1 is then completely detached from the pile la and the store 2, continuing along the conveyor 11 until it is engaged by the second routing roller 42 (fig. 4).

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.

However, it is understood that what has been described above is given by way of non-restrictive example. Therefore any variants of detail that may be necessary for technical and/or functional reasons, as well as alternative embodiments of the invention that are functionally equivalent, shall be considered as of now as coming within the same field of protection defined by the following claims.