An interfolding machine for production of paper material in packs of interfolded sheets

Abstract

The interfolding machine (100) is supplied with at least a continuous strip (N1, N2) of paper material which, by use of cutting means (R), is divided into a first part of continuous strip (N1A) and into a second part of continuous strip (N1B), and comprises a cutting and folding unit (TP) for realising scores in the two parts of continuous strips in order to obtain two series of sheets folded in an interfolded way to obtain two stacks (P1, P2) of distinct interfolded sheets. The interfolding machine comprises a first series of support tables (T1) for transferring the first stack (P1) of interfolded sheets onto a first transport unit (C1) and a second series of support tables (T2) for transferring the second stack (P2) of interfolded sheets onto a second transport unit (C2). The first transport unit (C1) and the second transport unit (C2) are activatable independently of one another so as to transport the first stack (P1) of interfolded sheets and the second stack (P2) of interfolded sheets externally of the interfolding machine through two respective distinct outlets (U1, U2), for the successive respective cutting into respective packs of interfolded sheets.

Description

[0001] AN INTERFOLDING MACHINE FOR PRODUCTION OF PAPER MATERIAL IN PACKS OF INTERFOLDED SHEETS

[0002] DESCRIPTION

[0003] FIELD OF THE INVENTION

[0004] The present invention relates to the technical sector concerning production of paper material in packs of interfolded sheets, i.e. with the sheets folded in a zig-zag with respect to one another, that is, enclosing at each fold a flap of the preceding sheet and a flap of the successive sheet, such as for example packs of paper handkerchieves, paper napkins, paper hand-towels, and the like.

[0005] DESCRIPTION OF THE PRIOR ART

[0006] In this technical sector, the production process includes providing at least a continuous strip of paper material, unwound from a reel, and then realising transversal scores, or transversal pre-tear lines, on the continuous strip, in such a way as to obtain, transversally of the continuous strip, a succession of sheets that are separated from one another or joined by the pre-tear lines.

[0007] The sheets are then folded in an interfolded way with respect to one another for the formation of a stack of sheets, known in the sector as a “log”.

[0008] When the stack of interfolded sheets has reached the predetermined height (i.e. the desired number of folded sheets) for the type of products, the formed stack of sheets is separated from the successive stack of interfolded sheets under formation.

[0009] The stack of interfolded sheets formed in this way, i.e. the log, and separated from the successive stack under formation, is transferred onto a conveyor belt. The conveyor belt transports the log into a cutting station, in which a series of transversal cuts is made in the log so as to obtain single packs that will constitute the final products.

[0010] The apparatuses designed to perform these operations are known as interfolding machines.

[0011] There are various types of interfolding machines according to the modalities in which the sheets are to be folded and interfolded for realising the final packs: for example, folding in a Z or W shape, with 3 or 4 panels, or folding in an L or V shape, with 2 panels, where the expression “panel” refers to each folded sheet.

[0012] There are interfolding machines which include the use of a single continuous strip of paper material, from which the single sheets to be folded are obtained or in an intercalated and interfolded way with respect to one another, or the use of two continuous strips of paper material from which two respective series of sheets are obtained to be partially superposed on one another and fold, in an intercalated and interfolded way, the sheets with respect to one another.

[0013] The interfolding machines comprise cutting means for realising the transversal scores, or transversal pre-tear lines, on the continuous strips of paper material so as to obtain a succession of sheets that are then to be folded and interfolded with respect to one another, i.e. in an intercalated way.

[0014] The cutting means usually comprise at least a roller, activatable in rotation about the relative axis, and which is provided on the relative lateral surface with cutting elements for scoring the band of paper material during the unwinding about the roller.

[0015] The interfolding machines also comprise folding units which are configured to fold the sheets, made from the cut or scoring of the continuous strips of paper material, in an interfolded way for the formation of successive stacks of interfolded sheets.

[0016] The folding units substantially comprise a pair of counter-rotating rollers which are destined to carry out a partial overlapping between successive sheets coming from cutting means, and folding elements (known as folding fingers) which must intercept the superposed sheets so as to carry out the relative folding in an intercalated way, i.e. interfolded.

[0017] There are interfolding machines in which the pair of counter-rotating rollers exerts an action of attraction and adherence, and then of release of the sheets, for the partial overlapping thereof, by means of a suction system, while in other interfolding machines the counter-rotating rollers exert a gripping and release action of the sheets, for the partial overlapping thereof, by means of a system of gripping elements of the plier type.

[0018] There are also interfolding machines in which the transversal scores on the continuous strips of paper material, for obtaining the sheets, and the folding of the sheets in an interfolded way are done using a single cutting and folding unit comprising a pair of counter-rotating rollers having, on the relative lateral surfaces, cutting elements and a suction system, for retaining and releasing the sheets so as to obtain the partial overlapping thereof, and folding elements (folding fingers) which must intercept the superposed sheets so as to carry out the relative folding in an intercalated way, i.e. interfolded.

[0019] In all the types of interfolding machines described in the foregoing support tables are present, arranged below the folding units, to restingly receive and support the stack of folded sheets under formation up to the reaching of a desired height and separating elements, for separating the formed stack (i.e. the log) from the successive stack of sheets under formation.

[0020] A conveyor belt is arranged below the interfolding machine, for restingly receiving the formed stack (log) from the support tables, and then transport the formed stack (the log) outside the interfolding machines, causing the log to exit from a side of the machine, along to a cutting station where the log is transversally cut so as to obtain single packs.

[0021] With the aim of increasing productivity, i.e. the number of packs that can be obtained from a log in a time unit (for example per minute), a consolidatated practice is to use continuous strips of paper material as wide as possible, with a consequent corresponding increase of the dimensions in terms of length of the rollers in the cutting units and in the folding units, as well as of the conveyor belt for receiving the formed log and to transport the log to outside the machine.

[0022] In this regard, some types of interfolding machines have a width of greater than 3 metres, for example up to 3.50 or 3.60 metres, and consequently also the cutting rollers and the folding rollers can reach a length of such dimensions.

[0023] In this type of interfolding machines, however, some drawbacks can emerge.

[0024] Firstly, given the significant length of the log that is formed, the conveyor belt will take a certain time to be able to completely transport the log laterally to outside the interfolding machine.

[0025] Consequently, the rotation velocity of the cutting rollers and the rotation velocity of the folding rollers, for the formation of the stack of interfolded sheets (i.e. the log), meaning the number of cycles per minute of the machine, must be set on the basis of the time necessary for the conveyor belt to transport the log laterally to outside the machine, so as to free up the space necessary to restingly receive the successive log.

[0026] To maintain a high level of number of cycles per minute, therefore, it is necessary to increase the activating velocity of the conveyor belt, though this can cause repercussions for the log, possibly leading to an eventual disintegragion thereof.

[0027] Further, the folding rollers, especially those which retain and release the sheets by means of a suction system, and which are internally hollow in order to be able to allow connection to a suction source, as they have a significant length, can be subject to flexion stresses which can flex the rollers, with consequent repercussions on the correct interfolded folding of the various sheets, and can also compromise the correct functioning of the interfolding machine.

[0028] SUMMARY OF THE INVENTION

[0029] The aim of the present invention is therefore to provide an interfolding machine able to obviate the above-mentioned drawbacks.

[0030] In particular, the aim of the invention is to provide an interfolding machine, that can be made in such a way as to comprise any type of cutting and folding units, for realising the folding, in an interfolded way, of a succession of sheets cut from one or two continuous strips of paper material each having a significant width, in the order of beyond three metres, and such as to enable maintaining high operating cycles.

[0031] The above aims are attained by an interfolding machine for production of paper material in packs of interfolded sheets according to the contents of the claims.

[0032] BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The characteristics of preferred, but not exclusive, embodiments of the interfolding machine of the present invention will be described in the following description with reference to the appended tables of drawings, in which:

[0034] - figure 1 is a schematic perspective view of the interfolding machine of the invention in a first possible though not exclusive embodiment; - figure 2 schematically illustrates, in a perspective view, some components of the interfolding machine;

[0035] - figure 3 schematically illustrates, in a perspective view, the interfolding machine of the invention, on the basis of a second embodiment;

[0036] - figure 4 schematically illustrates, in a perspective view, the interfolding machine of the invention, in a further and other possible embodiment;

[0037] - figure 5 is a schematic lateral view of some parts of the interfolding machine of the present invention, in which the parts relative to the cutting and folding units have not been illustrated in detail;

[0038] - figure 6 is a view according to a vertical longitudinal section plane of the interfolding machine of the invention, in a possible embodiment, in which the parts relative to the cutting and folding units have not been illustrated in detail;

[0039] - figure 7 is a perspective view of figure 6;

[0040] - figure 8 is a view according to a vertical longitudinal section plane of the interfolding machine of the invention, according to a possible embodiment, in which the parts relative to the cutting and folding units have not been illustrated in detail;

[0041] - figure 9 is a perspective view of the interfolding machine of the invention, sectioned according to a vertical longitudinal section plane, in a possible further and other embodiment, in which the parts relative to the cutting and folding units have not been illustrated in detail;

[0042] - figure 10 is a frontal view of the interfolding machine of figure 9 in a possible operating configuration;

[0043] - figure 11 is a schematic lateral view of the interfolding machine of the invention in a further and other possible embodiment, in which the parts relative to the cutting and folding units have not been illustrated in detail;

[0044] - figure 12 is a perspective view of the interfolding machine of the invention of figure 11, sectioned according to a vertical longitudinal section plane, in which the parts relative to the cutting and folding units have not been illustrated in detail;

[0045] - figure 13 is a frontal view of the interfolding machine of figure 12; figure 14 is a frontal view of the interfolding machine of figure 13 in a particular operating step; - figures 15 and 16 illustrate, according to respective perspective views carried out from different angles, the interfolding machine of the invention in a further and other possible embodiment;

[0046] - figure 17 is a lateral view of the interfolding machine of the invention, in a possible embodiment comprising a first type of cutting and folding units;

[0047] - figure 18 is a perspective view of the interfolding machine of the invention of figure 17, sectioned according to a vertical longitudinal section plane;

[0048] - figure 19 schematically illustrates a perspective view of a significant component present in the folding unit of the interfolding machine of the invention of figures 17 and 18;

[0049] - figures 20 and 21 illustrate respective partial section views, taken from different transversal section planes, of the component of figure 19;

[0050] - figure 22 illustrates, in a lateral schematic view, in section, the components of the cutting and folding unit that can be present in the interfolding machine of the invention, of figures 17 and 18;

[0051] - figure 23 schematically illustrates, in a lateral view, partially sectioned, the components of another type of cutting and folding units that can be present in the interfolding machine of the invention;

[0052] - figure 24 schematically illustrates, schematically and in a lateral view, partially sectioned, the components of another type of cutting and folding units that can be present in the interfolding machine of the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0053] With reference to the accompanying tables of drawings, reference numeral (100) denotes the interfolding machine for production of paper material in packs of interfolded sheets, object of the present invention in its entirety.

[0054] The interfolding machine (100) is configured so as to be supplied with at least a continuous strip (N1, N2) of paper material and comprises a cutting and folding unit (TP); support tables (T, T1, T2); separating elements (S, S1 , S2), and a transport system (C), which is arranged inferiorly of the support tables (T, T1 , T2).

[0055] The interfolding machine (100) is provided with cutting means (R) (see for example figures 1, 2, 3, and 4) which are arranged and configured to longitudinally cut the at least a continuous strip (N1, N2) of paper material and to divide the at least a continuous strip (N1 , N2) of paper material into two parts and obtain a first part of continuous strip (N1A, N2A) of paper material and a second part of continuous strip (N1 B, N2B) of paper material.

[0056] For example, the cutting means (R) can comprise at least a circular cutter (R1) and at least a counter-roller (R2) acting as a contrast roller, arranged facing one another, and on an opposite side to the at least a circular cutter (R1) with respect to the at least a continuous strip (N1 , N2) of paper material which is to be cut and divided into two parts.

[0057] The interfolding machine (100) is realised in such a way that the cutting and folding unit (TP) is configured: to receive the first part of continuous strip (N1A, N2A) of paper material and the second part of continuous strip (N1 B, N2B) of paper material; to realise scores in the first part of continuous strip (N1A, N2A) of paper material and to obtain a first series of sheets andr to realise scores in the second part of continuous strip and to obtain a second series of sheets; to fold in an interfolded way the first series of sheets and to fold in an interfolded way the second series of sheets.

[0058] The interfolding machine (100) can be configured in such a way that the cutting and folding unit (TP) is realised in various possible embodiments usually utilised to carry out scores and folding of sheets in an interfolded way.

[0059] In this matter, in figures 6-16 the cutting and folding unit (TP) has not been illustrated in detail in relation to the parts thereof, as it can be realised according to one of any preferred embodiments illustrated in figures from 17 to 24, which will be successively described in the following.

[0060] The cutting and folding unit (TP) can also be realised in other ways usually utilised in interfolding machines different to the ones described and illustrated in figures from 17 to 24.

[0061] The particular embodiment of the cutting and folding unit is in fact not correlated to the special and salient aspects of the present invention.

[0062] The interfolding machine (100) is configured in such a way that: a first series of support tables (T1) of the support tables (T, T1, T2) are configured to restingly receive the sheets folded in an interfolded way of the first series of sheets folded in an interfolded way and so as to form a first stack (P1) of interfolded sheets and in such a way that a first series of separating elements (S1) of the separating elements (S, S1, S2) are configured to separate the first stack (P1) of interfolded sheets from a successive stack of sheets folded in an interfolded way under formation of the first series of sheets; a second series of support tables (T2) of the support tables (T, T1, T2) are configured to restingly receive the sheets folded in an interfolded way of the second series of sheets of the second series of sheets and to form a second stack (P2) of interfolded sheets and in such a way that a second series of separating elements (S2) of the separating elements (S, S1, S2) are configured to separate the second stack (P2) of interfolded sheets from a successive stack of sheets folded in an interfolded way under formation of the second series of sheets.

[0063] Further, the interfolding machine (100) is configured in such a way that the transport system (C) is configured in such a way as to comprise: a first transport unit (C 1 ), arranged inferiorly of the first series of support tables (T1) and a second transport unit (C2), arranged inferiorly of the second series of support tables (T2); with the first series of support tables (T1) being configured to be vertically translatable in such a way as to bring the first stack (P1) of interfolded sheets to rest on the first transport unit (C1); with the second series of support tables (T2) being configured to be vertically translatable in such a way as to bring the second stack (P2) of interfolded sheets to rest on the second transport unit (C2).

[0064] In this way, a first stack (P1) of interfolded sheets will be deposited on the first transport unit (C1) and a second stack of interfolded sheets (P2) will be deposited on the second transport unit (C2).

[0065] The support tables of the first series of support tables, as well as the support tables of the second series of support tables, can be activatable in translation independently of one another, or can depend on using a single translation means, such as for example a respective beam.

[0066] The first transport unit (C1) and the second transport unit (C2) are activatable independently of one another so as to transport the first stack (P1) of interfolded sheets and the second stack (P2) of interfolded sheets externally of the interfolding machine through two respective distinct outlets (U1 , U2), for the successive respective cutting-off into respective packs of interfolded sheets.

[0067] The advantageous aspects of the interfolding machine of the present invention are obvious.

[0068] Owing to the division of the at least a continuous strip of paper material into two respective parts of continuous strips, the interfolding machine with the relative cutting and folding unit is thus able to process the two respective parts of continuous strips and to obtain two distinct stacks of interfolded sheets, which two distinct stacks of interfolded sheets are deposited resting on two distinct transport units which, independently of one another, transport the two stacks of interfolded sheets externally of the machine, via two respective distinctive outlets.

[0069] The two stacks of interfolded sheets can then be separately sectioned transversally so as to obtain respective packs of interfolded sheets.

[0070] In this way, the times for taking the interfolded products grouped in stacks outside the interfolding machine, or at least to free up the area below the support tables, are considerably reduced with respect to the prior art, enabling the machine cycles for forming the stacks of interfolded sheets to be kept high, and eliminating the risk of disintegration of the stacks as it is not necessary to transport them outside the machine at a velocity that is over-hurried.

[0071] Further advantageous aspects of the interfolding machine of the present invention are described in the following.

[0072] The first transport unit (C1) and the second transport unit (C2) are arranged and configured to respectively transport the first stack (P1) of interfolded sheets and the second stack (P2) of interfolded sheets externally of the interfolding machine (100) through two respective distinct outlets (U1, U2) which are situated on two opposite sides (L1, L2) of the interfolding machine (100) or through two respective distinct outlets (U1 , U2) which are situated on a same side (L1) of the interfolding machine (100).

[0073] In a possible preferred first embodiment, illustrated in figures from 5 to 8, the first transport unit (C1) can comprise a first loop-wound conveyor belt (1) and the second transport unit (C2) can comprise a second loop-wound conveyor belt (2), which are arranged aligned or substantially aligned to one another, in the sense that they can be at a same height from the ground surface, or substantially at a same height.

[0074] The first loop-wound conveyor belt (1) is arranged inferiorly of the first series of support tables (T1) and is configured in such a way as to restingly receive, from the first series of support tables (T1), the first stack (P1) of interfolded sheets, and is activatable to transport the first stack (P1) of interfolded sheets externally of the interfolding machine (100) through a first outlet (U1) situated on a first side (L1) of the interfolding machine (100), while the second loopwound conveyor belt (2) is arranged inferiorly of the second series of support tables (T2) and configured in such a way as to restingly receive, from the second series of support tables (T2), the second stack (P2) of interfolded sheets and is activatable to transport the second stack (P2) of interfolded sheets externally of the interfolding machine (100) through a second outlet (U2) situated on a second side (L2) of the interfolding machine (100), opposite the first side (L1).

[0075] With this configuration, there is also the possibility that the interfolding machine can realise two distinct stacks of interfolded sheets having different heights, such as for example illustrated in figure 8, and thus, with one interfolding machine only it would be possible to make two different types of final packs of interfolded sheets.

[0076] In another possible preferred embodiment, illustrated in figures 9 and 10, the first transport unit (C1) can comprise a first loop-wound conveyor belt (1) and the second transport unit (C2) can comprise a second loop-wound conveyor belt (2) and a third loop-wound conveyor belt (3).

[0077] The first loop-wound conveyor belt (1) and the second loop-wound conveyor belt (2) are arranged aligned to one another and the third loop-wound conveyor belt (3) is arranged inferiorly of the first loop-wound conveyor belt (1) and of the second loop-wound conveyor belt (2).

[0078] The first loop-wound conveyor belt (1) is arranged inferiorly of the first series of support tables (T1) and is configured in such a way as to restingly receive, from the first series of support tables (T1), the first stack (P1) of interfolded sheets and is activatable to transport the first stack (P1) of interfolded sheets externally of the interfolding machine (100) through a first outlet (U1) situated on a first side (L1) of the interfolding machine (100).

[0079] In turn, the second loop-wound conveyor belt (2) is arranged inferiorly of the second series of support tables (T2) and is configured in such a way as to be tilting about a rotation axis in such a way as to be movable between a first configuration (01) (figure 9), in which it is aligned with the first loop-wound conveyor belt (1) so as to restingly receive, from the second series of support tables (T2), the second stack (P2) of interfolded sheets, and a second inclined configuration (02) (figure 10) in such a way that a relative end can be arranged at the third loop-wound conveyor belt (3) in order to be then activatable to transfer the second stack (P2) of interfolded sheets to rest on the third loop-wound conveyor belt (3).

[0080] In this regard, the third loop-wound conveyor belt (3) is thus configured in such a way as to receive the second stack (P2) of interfolded sheets from the second loop-wound conveyor belt (2) and is activatable to transport the second stack (P2) of interfolded sheets externally of the interfolding machine (100) through a second outlet (U2) situated on the same first side (L1) of the interfolding machine (100).

[0081] Possibly, in another possible embodiment, not illustrated, the third loop-wound conveyor belt (3) can have an extension such as to be able to transport the second stack (P2) of interfolded sheets externally of the interfolding machine (100) through a second outlet situated on a second side of the interfolding machine, opposite the first side.

[0082] In a third other preferred embodiment of the interfolding machine, see figures from 11 to 14, the first transport unit (C1) can comprise a first loop-wound conveyor belt (1) and the second transport unit (C2) can comprise a second loop-wound conveyor belt (2).

[0083] The second loop-wound conveyor belt (2) is arranged inferiorly of the first loop-wound conveyor belt (1), with the first loop-wound conveyor belt (1) being arranged inferiorly of the first series of support tables (T1), and is configured in such a way as to restingly receive, from the first series of support tables (T1), the first stack of interfolded sheets (P1) and is activatable to transport the first stack (P1) of interfolded sheets externally of the interfolding machine (100) through a first outlet (U1) situated on a first side (L1) of the interfolding machine (100), with the second conveyor belt (2) being destined to restingly receive the second stack (P2) of interfolded sheets.

[0084] The second conveyor belt (2) can have an extension such as to be able to transport the second stack (P2) of interfolded sheets externally of the interfolding machine (100) through a second outlet (U2) situated on the same first side (L1) of the interfolding machine (100), or through a second outlet situated on a second side of the interfolding machine, opposite the first side.

[0085] In this case, i.e. when the second loop-wound conveyor belt (2) is arranged inferiorly, that is, at a lower height from the ground surface with respect to the first loop-wound conveyor belt (1), the interfolding machine (100) can advantageously be configured in such a way as also to comprise a third series of support tables (T3) which are arranged inferiorly of the second series of support tables (T2) and which are configured to restingly receive from the second series of support tables (T2) the second stack (P2) of interfolded sheets and which are vertically translatable in such a way as to transfer the second stack (P2) of interfolded sheets to rest on the second loop-wound conveyor belt (2).

[0086] In turn, the second loop-wound conveyor belt (2) is configured and activatable to transport the second stack (P2) of interfolded sheets externally of the interfolding machine (100) through a second outlet (U2) situated on the same first side (L1) of the interfolding machine (100), or through a second outlet situated on a second side of the interfolding machine, opposite the first side. On the basis of a further preferred embodiment of the interfolding machine, see for example figures 15 and 16, the first transport unit (C1) can comprise a first series of belts (10) arranged inferiorly of the first series of support tables (T1) and transversally with respect to a longitudinal axis of the interfolding machine (100), and a first loop-wound conveyor belt (1) arranged transversally to the first series of belts (10) at an end thereof.

[0087] The first series of belts (10) are configured to restingly receive from the first series of support tables (T1) the first stack (P1) of interfolded sheets and are activatable to transfer the first stack (P1) of interfolded sheets onto the first loop-wound conveyor belt (1), with the first loop-wound conveyor belt (1) being activatable to transport the first stack (P1) of interfolded sheets externally of the interfolding machine (100) through a first outlet (U1) situated on a first side (L1) of the interfolding machine (100).

[0088] In turn, the second transport unit (C2) comprises a second series of belts (20) arranged inferiorly of the second series of support tables (T2) and transversally with respect to a longitudinal axis of the interfolding machine (100), and a second loop-wound conveyor belt (2) arranged transversally to the second series of belts (20) at an end thereof.

[0089] The second series of belts (20) are configured to restingly receive from the second series of support tables (T2) the second stack (P2) of interfolded sheets and are activatable to transfer the second stack (P2) of interfolded sheets (P2) onto the second loop-wound conveyor belt (2), with the second loop-wound conveyor belt (2) being activatable to transport the second stack (P2) of interfolded sheets externally of the interfolding machine (100) through a second outlet (U2) situated on a second side (L2) of the interfolding machine (100), opposite the first side (L1).

[0090] On the basis of the type of cutting and folding unit installed in the interfolding machine, it can be supplied with one or two continuous strips of paper material, as illustrated in figures 1, 3 and 4.

[0091] When the interfolding machine is configured to be supplied with two continuous strips (N1, N2) of paper material, the cutting means (R) are arranged and configured to longitudinally cut each of the two continuous strips (N1, N2) of paper material and to divide each of the two continuous strips of paper material into two respective parts (N1A, N1B, N2A, N2B).

[0092] In a further aspect, the interfolding machine can comprise distancing means (D), which are arranged and configured in such a way as to move, away from one another, the parts (N1A, N1B, N2A, N2B) which are cut and divided by the cutting means (R) from a respective continuous strip (N1, N2) of paper material.

[0093] Figures 17, 18, 19, 20, 21 and 22 schematically illustrate the components of a first possible cutting and folding unit (TP) which can be installed in the interfolding machine (100) of the present invention, when it is supplied with two continuous strips of paper material.

[0094] In this possible configuration for the interfolding machine of the invention, the cutting and folding unit (TP) is configured to receive a first part (N1A) cut from the first continuous strip (N1) of paper material and a first part (N2A) cut from the second continuous strip (N2) of paper material so as to realise scores in these first parts (N1A, N2A) and to obtain first series of sheets and to fold, by means of suction, and superposing the first series of sheets at least partially, in an interfolded way to form the first stack (P1) of interfolded sheets resting on the first series of support tables (T1) of the support tables (T, T1, T2), and wherein the cutting and folding unit (TP) is configured to receive a second part (N1B) cut from the first continuous strip (N1) of paper material and a second part (N2B) cut from the second continuous strip (N2) of paper material so as to realise scores in these second parts and to obtain second series of sheets and fold by means of suction, and partially superposing the second series of sheets at least partially in an interfolded way to form the second stack (P2) of interfolded sheets resting on the second series of support tables (T2) of the support tables (T 1 , T2).

[0095] In this regard, the cutting and folding unit comprises a pair of cutting rollers (3) and a pair of folding rollers (4), arranged inferiorly of the pair of cutting rollers (3), wherein the pair of cutting rollers (3) are arranged facing one another, are activatable in counter-rotation and comprise scoring elements (31) on the relative lateral surfaces.

[0096] The pair of folding rollers (4) are arranged facing one another and are activatable in counter-rotation, with each of the folding rollers (4) comprising a longitudinal central channel (40) for air passage connected to a source of compressed air, and axial channels (41) for air passage connected to the source of compressed air, a first series of holes (42) being selectively connectable to the longitudinal central channel (40) for air passage and a second series of holes (43) being selectively connectable to the axial channels (41) for air passage (see in particular figure 22).

[0097] By selectively and alternatively connecting the first series of holes and the second series of holes to the suction source, with the folding rollers it is possible to exert retaining actions, by suction, and release on the sheets, carrying out a partial overlapping and at the same time an interfolding thereof.

[0098] In a further particularly advantageous aspect (see in particular figures from 19 to 21), each roller (4) of the pair of folding rollers (4) is constituted by two semi-rollers (44) joined to one another at a respective end by means of a central support (45) comprising a looped connecting element (46), joined to the ends of the two semi-rollers (44), and a support element (47) comprising a first part (48) shaped as an annular flange mounted coaxially, by an interpositioning of sliding elements (S) (such as for example bearings), on the connecting element (46) and a second part (49) is conformed so as to be constrained to a portion of a frame of the interfolding machine (100).

[0099] Further, each semi-roller (44) comprises, in proximity of the central support (45), a bell-shaped element (50), internally hollow, and communicating with the axial channels (41) for air passage and connected to the suction source.

[0100] As each folding roller is subdivided into two semi-rollers, each of which provided for the realisation of respective stacks of interfolded sheets, joined and supported by means of a central support, it is possible to prevent and obviate any drawbacks relating to flexion that might be encounter in the prior art interfolding machines, when they have large width dimensions.

[0101] Figure 23 schematically illustrates the components of a further other possible cutting and folding unit (TP) which can be installed in the interfolding machine (100) of the present invention, when it is supplied with two continuous strips of paper material.

[0102] In this case, the cutting and folding unit (TP) comprises: a cutting roller (5) provided on the relative lateral surface with scoring elements (51) in order to realise scores in the divided parts (N1A, N1 B) of the continuous strip (N1) of paper material and to obtain a first series of sheets and a second series of sheets; a pair of transfer rollers (52) that are arranged inferiorly of the cutting roller (5) and in cascade with respect to one another, configured to realise, by means of suction, a first partial superposition of the first series of sheets and of the second series of sheets.

[0103] The cutting and folding unit further comprises a pair of folding rollers (53), facing one another and activatable in counter-rotation, and comprising, on the lateral surfaces thereof, folding elements in plier form (54) which are activatable to grip and release the sheets of the first series of sheets and the sheets of the second series of sheets in such a way as to fold them with respect to one another in an interfolded way for the formation of the first stack (P1) of interfolded sheets and of the second stack (P2) of interfolded sheets.

[0104] Figure 24 schematically illustrates the components of a further other possible cutting and folding unit (TP) which can be installed in the interfolding machine (100) of the present invention, when it is supplied with two continuous strips of paper material.

[0105] In this case, the cutting and folding unit (TP) comprises a pair of cutting and folding rollers (6), arranged facing one another and activatable in counterrotation, wherein each cutting and folding roller (6) comprises, on the lateral surface thereof, scoring elements (61), for making scores on the first parts (N1A, N2A) and on the second parts (N1B, N2B) divided from the first (N1) and the second continuous strip (N2) of paper material and to obtain first series of sheets and second series of sheets, and a series of holes (62), intercalated with the scoring elements (61), selectively connectable with a central axial channel (63) for air passage connected to a source of compressed air, for retaining by suction and releasing the sheets of the first series of sheets and the sheets of the second series of sheets in such a way as to fold the sheets with respect to one another in an interfolded way for the formation of the first stack (P1) of interfolded sheets and of the second stack (P2) of interfolded sheets.

[0106] The cutting and folding unit (TP) can also be realised in other ways of known type with respect to the preferred embodiments illustrated in the foregoing, all falling within the scope of protection of the present invention.

Claims

CLAIMS1) An interfolding machine (100) for production of paper material in packs of interfolded sheets, configured so as to be supplied with at least a continuous strip (N1 , N2) of paper material, and comprising: a cutting and folding unit (TP); support tables (T, T1, T2); separating elements (S, S1, S2); a transport system (C), arranged inferiorly of the support tables (T, T1, T2); characterised in that it comprises: cutting means (R), arranged and configured to longitudinally cut the at least a continuous strip (N1, N2) of paper material and to divide the at least a continuous strip (N1, N2) of paper material into two parts and obtain a first part of continuous strip (N1A, N2A) of paper material and a second part of continuous strip (N1B, N2B) of paper material; wherein the cutting and folding unit (TP) is configured: to receive the first part of continuous strip (N1A, N2A) of paper material and the second part of continuous strip (N1 B, N2B) of paper material; to realise scores in the first part of continuous strip (N1A, N2A) of paper material and to obtain a first series of sheets and to realise scores in the second part of continuous strip (N1 B, N2B) and to obtain a second series of sheets; to fold in an interfolded way the first series of sheets and to fold in an interfolded way the second series of sheets; wherein a first series of support tables (T1) of the support tables (T, T1, T2) are configured to restingly receive the sheets folded in an interfolded way of the first series of sheets and to form a first stack (P1) of interfolded sheets and wherein a first series of separating elements (S1) of the separating elements (S, S1, S2) are configured to separate the first stack (P1) of interfolded sheets from a successive stack of sheets folded in an interfolded way under formation of the first series of sheets; wherein a second series of support tables (T2) of the support tables (T, T1, T2) are configured to restingly receive the sheets folded in an interfolded wayof the second series of sheets and to form a second stack (P2) of interfolded sheets and wherein a second series of separating elements (S2) of the separating elements (S, S1, S2) are configured to separate the second stack (P2) of interfolded sheets from a successive stack of sheets folded in an interfolded way under formation of the second series of sheets; wherein the transport system (C) is configured in such a way as to comprise: a first transport unit (C 1 ), arranged inferiorly of the first series of support tables (T1) and a second transport unit (C2), arranged inferiorly of the second series of support tables (T2); wherein the first series of support tables (T1) are configured to be vertically translatable in such a way as to bring the first stack (P1) of interfolded sheets to rest on the first transport unit (C1); wherein the second series of support tables (T2) are configured to be vertically translatable in such a way as to bring the second stack (P2) of interfolded sheets to rest on the second transport unit (C2); wherein the first transport unit (C1) and the second transport unit (C2) are activatable independently of one another so as to transport the first stack (P1) of interfolded sheets and the second stack (P2) of interfolded sheets externally of the interfolding machine through two respective distinct outlets (U1, U2), for the successive respective cutting-off into respective packs of interfolded sheets.2) The interfolding machine (100) as claimed in claim 1, wherein the first transport unit (C1) and the second transport unit (C2) are arranged and configured to respectively transport the first stack (P1) of interfolded sheets and the second stack (P2) of interfolded sheets externally of the interfolding machine (100) through two respective distinct outlets (U1, U2) which are situated on two opposite sides (L1 , L2) of the interfolding machine (100) or through two respective distinct outlets (U1, U2) which are situated on a same side (L1) of the interfolding machine (100).3) The interfolding machine (100) as claimed in claim 2, wherein the first transport unit (C1) comprises a first loop-wound conveyor belt (1) and the second transport unit (C2) comprises a second loop-wound conveyor belt (2), which are arranged aligned to one another, wherein the first loop-woundconveyor belt (1) is arranged inferiorly of the first series of support tables (T1) and configured in such a way as to restingly receive, from the first series of support tables (T1), the first stack (P1) of interfolded sheets and is activatable to transport the first stack (P1) of interfolded sheets externally of the interfolding machine (100) through a first outlet (U1) situated on a first side (L1) of the interfolding machine (100), wherein the second loop-wound conveyor belt (2) is arranged inferiorly of the second series of support tables (T2) and configured in such a way as to restingly receive, from the second series of support tables (T2), the second stack (P2) of interfolded sheets and is activatable to transport the second stack (P2) of interfolded sheets externally of the interfolding machine (100) through a second outlet (L2) situated on a second side (L2) of the interfolding machine (100), opposite the first side (L1).4) The interfolding machine (100) as claimed in claim 2, wherein the first transport unit (C1) comprises a first loop-wound conveyor belt (1) and the second transport unit (C2) comprises a second loop-wound conveyor belt (2) and a third loop-wound conveyor belt (3), wherein the first loop-wound conveyor belt (1) and the second loop-wound conveyor belt (2) are arranged aligned to one another and the third loop-wound conveyor belt (3) is arranged inferiorly of the first loop-wound conveyor belt (1) and of the second loopwound conveyor belt (2), wherein the first loop-wound conveyor belt (1) is arranged inferiorly of the first series of support tables (T1) and is configured in such a way as to restingly receive, from the first series of support tables (T1), the first stack (P1) of interfolded sheets and is activatable to transport the first stack (P1) of interfolded sheets externally of the interfolding machine (100) through a first outlet (U1) situated on a first side (L1) of the interfolding machine (100), wherein the second loop-wound conveyor belt (2) is arranged inferiorly of the second series of support tables (T2) and is configured in such a way as to be tilting about a rotation axis in such a way as to be movable between a first configuration (01), wherein the second loop-wound conveyor belt is aligned to the first loop-wound conveyor belt (1) so as to restingly receive, from the second series of support tables (T2), the second stack (P2) of interfolded sheets, and a second inclined configuration (02) in such a waythat a relative end can be arranged at the third loop-wound conveyor belt (3) in order to be then activatable to transfer the second stack (P2) of interfolded sheets to rest on the third loop-wound conveyor belt (3), and wherein the third loop-wound conveyor belt (3) is configured in such a way as to receive the second stack (P2) of interfolded sheets from the second loop-wound conveyor belt (2) and is activatable to transport the second stack (P2) of interfolded sheets externally of the interfolding machine (100) through a second outlet (U2) situated on the same first side (L1) of the interfolding machine (100), or through a second outlet situated on a second side of the interfolding machine (100), opposite the first side.5) The interfolding machine (100) as claimed in claim 2, wherein the first transport unit (C1) comprises a first loop-wound conveyor belt (1) and the second transport unit (C2) comprises a second loop-wound conveyor belt (2), wherein the second loop-wound conveyor belt (2) is arranged inferiorly of the first loop-wound conveyor belt (1), wherein the first loop-wound conveyor belt (1) is arranged inferiorly of the first series of support tables (T1) and is configured in such a way as to restingly receive, from the first series of support tables (T1), the first stack (P1) of interfolded sheets and is activatable to transport the first stack (P1) of interfolded sheets externally of the interfolding machine (100) through a first outlet (U1) situated on a first side (L1) of the interfolding machine (100), wherein the second loop-wound conveyor belt (2) is destined to restingly receive the second stack (P2) of interfolded sheets and is configured to be activatable so as to transport the second stack (P2) of interfolded sheets externally of the interfolding machine (100) through a second outlet (U2) situated on the same first side (L1) of the interfolding machine (100), or through a second outlet situated on a second side of the interfolding machine (100), opposite the first side.6) The interfolding machine (100) as claimed in claim 5, wherein the interfolding machine (100) is configured in such a way as to comprise a third series of support tables (T3) arranged inferiorly of the second series of support tables (T2) and which are configured to restingly receive the second stack (P2) of interfolded sheets from the second series of support tables (T2) and which are vertically translatable in such a way as to transfer the second stack(P2) of interfolded sheets to rest on the second loop-wound conveyor belt (2), wherein the second loop-wound conveyor belt (2) is configured and activatable to transport the second stack (P2) of interfolded sheets externally of the interfolding machine (100) through a second outlet (U2) situated on the same first side (L1) of the interfolding machine (100), or through a second outlet situated on a second side of the interfolding machine (100), opposite the first side.7) The interfolding machine (100) as claimed in claim 2, wherein the first transport unit (C1) comprises a first series of belts (10) arranged inferiorly of the first series of support tables (T1) and transversally with respect to a longitudinal axis of the interfolding machine (100), and a first loop-wound conveyor belt (1) arranged transversally to the first series of belts (10) at an end thereof, wherein the first series of belts (10) are configured to restingly receive, from the first series of support tables (T1), the first stack (P1) of interfolded sheets, and are activatable to transfer the first stack (P1) of interfolded sheets onto the first loop-wound conveyor belt (1), with the first loop-wound conveyor belt (1) being activatable to transport the first stack (P1) of interfolded sheets externally of the interfolding machine (100) through a first outlet (U1) situated on a first side (L1) of the interfolding machine (100), wherein the second transport unit (C2) comprises a second series of belts (20) arranged inferiorly of the second series of support tables (T2) and transversally with respect to a longitudinal axis of the interfolding machine (100), and a second loop-wound conveyor belt (2) arranged transversally to the second series of belts (20) at an end thereof, wherein the second series of belts (20) are configured to restingly receive from the second series of support tables (T2) the second stack (P2) of interfolded sheets and are activatable to transfer the second stack (P2) of interfolded sheets (P2) onto the second loopwound conveyor belt (2), with the second loop-wound conveyor belt (2) being activatable to transport the second stack (P2) of interfolded sheets externally of the interfolding machine (100) through a second outlet (U2) situated on a second side (L2) of the interfolding machine (100), opposite the first side (L1).8) The interfolding machine (100) as claimed in any one of claims from 2 to 7, configured so as to be supplied with two continuous strips (N1, N2) of papermaterial, wherein the cutting means (R) are arranged and configured to longitudinally cut each of the two continuous strips (N1, N2) of paper material so as to divide each of the two continuous strips of paper material into two respective parts (N1A, N1B, N2A, N2B).9) The interfolding machine (100) as claimed in any one of the preceding claims, comprising distancing means (D), arranged and configured in such a way as to move away from one another the parts (N1A, N1 B, N2A, N2B) which are cut and divided by the cutting means (R) from a respective continuous strip (N1, N2) of paper material.10) The interfolding machine (100) as claimed in any one of claims 8 and 9, wherein the cutting and folding unit (TP) is configured to receive a first part (N1A) cut from the first continuous strip (N1) of paper material and a first part (N2A) cut from the second continuous strip (N2) of paper material so as to realise scores in these first parts (N1A, N2A) and to obtain first series of sheets and to fold, by means of suction, and superposing the first series of sheets at least partially, in an interfolded way to form the first stack (P1) of interfolded sheets resting on the first series of support tables (T1) of the support tables (T, T1, T2), and wherein the cutting and folding unit (TP) is configured to receive a second part (N1 B) cut from the first continuous strip (N1) of paper material and a second part (N2B) cut from the second continuous strip (N2) of paper material so as to realise scores in these second parts (N1 B, N2B) and to obtain a second series of sheets and fold by means of suction, and superposing the second series of sheets at least partially, in an interfolded way to form the second stack (P2) of interfolded sheets resting on the second series of support tables (T2) of the support tables (T1, T2).11) The interfolding machine (100) as claimed in claim 10, wherein the cutting and folding unit comprises a pair of cutting rollers (3) and a pair of folding rollers (4), arranged inferiorly of the pair of cutting rollers (3), wherein the pair of cutting rollers (3) are arranged facing one another, are activatable in counter-rotation and comprise scoring elements (31) on the relative lateral surfaces, wherein the pair of folding rollers (4) are arranged facing one another and are activatable in counter-rotation, with each of the folding rollers (4) comprising a longitudinal central channel (40) for air passage connected toa source of compressed air, and axial channels (41) for air passage connected to the source of compressed air, a first series of holes (42) being selectively connectable to the longitudinal central channel (40) for air passage and a second series of holes (43) being selectively connectable to the axial channels (41) for air passage.12) The interfolding machine (100) as claimed in claim 11, wherein each roller (4) of the pair of folding rollers (4) is constituted by two semi-rollers (44) joined to one another at a respective end by means of a central support (45) comprising a looped connecting element (46), joined to the ends of the two semi-rollers (44), and a support element (47) comprising a first part (48) shaped as an annular flange mounted coaxially, by an interpositioning of sliding elements (S), on the connecting element (46) and a second part (49) conformed so as to be constrained to a portion of a frame of the interfolding machine (100).13) The interfolding machine (100) as claimed in claim 12, wherein each semiroller (44) comprises, in proximity of the central support (45), a bell-shaped element (50), internally hollow, and communicating with the axial channels (41) for air passage and connected to the suction source.14) The interfolding machine (100) as claimed in any one of claims from 1 to 9, wherein the cutting and folding unit (TP) comprises: a cutting roller (5) provided on the relative lateral surface with scoring elements (51) in order to realise scores in the divided parts (N1A, N1 B) of the continuous strip (N1) of paper material and to obtain a first series of sheets and a second series of sheets; a pair of transfer rollers (52) arranged inferiorly of the cutting roller (5) and in cascade with respect to one another, configured to realise, by means of suction, a first partial superposition of the first series of sheets and of the second series of sheets; and a pair of folding rollers (53), facing one another and activatable in counter-rotation, and comprising, on the lateral surfaces thereof, folding elements in plier form (54) which are activatable to grip and release the sheets of the first series of sheets and the sheets of the second series of sheets in such a way as to fold them with respect to one another in an interfolded way for the formation of the first stack (P1 ) of interfolded sheets and of the second stack (P2) of interfolded sheets.15) The interfolding machine (100) as claimed in any one of claims from 8 to 9, wherein the cutting and folding unit (TP) comprises a pair of cutting and folding rollers (6), arranged facing one another and activatable in counterrotation, wherein each cutting and folding roller (6) comprises, on the lateral surface thereof, scoring elements (61), for making scores on the first parts (N1A, N2A) and on the second parts (N1B, N2B) divided from the first (N1) and the second continuous strip (N2) of paper material and to obtain first series of sheets and second series of sheets, and a series of holes (62), intercalated with the scoring elements (61), selectively connectable with a central axial channel (63) for air passage connected to a source of compressed air, for retaining and releasing the sheets of the first series of sheets and the sheets of the second series of sheets in such a way as to fold the sheets with respect to one another in an interfolded way for the formation of the first stack (P1) of interfolded sheets and of the second stack (P2) of interfolded sheets.

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