Web or sheet conveying unit for paper converting machines and folding or interfolding machine with such conveying unit

Abstract

A conveying unit (100) of a web, or sheet, of paper, or similar products, arranged to transfer along a transfer direction the web, or sheet, of paper, having a support (41) having a lateral surface (42) provided with at least one peripheral suction groove (43). A suction belt (45) is arranged to move along a closed trajectory (46) comprising the suction portion (44). The suction belt (45) is configured to air-tightly engage the suction portion and provides at least one through hole (47) arranged to be positioned at a respective suction portion (43) in order to cause a suction effect on the web, or sheet, and to transfer it from a first point P1 to a second point P2 of a production line of paper products. It is, furthermore, provided a driving device (60) configured to move the suction belt (45) with respect to the support (41).

Claims

1. A folding or interfolding machine comprising: a folding, or interfolding, section, arranged to fold, or interfold, a web of paper, or a plurality of sheets of paper into a plurality of panels, according to a predetermined folding, or interfolding, configuration; said machine wherein said folding, or interfolding, section, comprises: a first and a second support facing each other in a central zone and having respective lateral surfaces provided with at least one peripheral suction groove extending on said lateral surface for a predetermined length, said, or each, peripheral suction groove pneumatically connected to an air suction system in such a way to define a corresponding suction portion on the lateral surface of the respective support; a first and a second suction belt arranged to move respectively along a first and a second closed trajectory, said first and second closed trajectory comprising, respectively, said suction portions of said first and second support, said first and second suction belt configured to air-tightly engage with said suction portions and providing at least one through hole arranged to be positioned at a respective suction portion for causing a suction on said web, or said sheets; a driving device configured to move said first and second suction belt with respect to said support, in such a way that said through holes of the first, or the second, belt are located at said central zone shifted from each other.

2. The folding or interfolding machine according to claim 1, wherein a feeding section is furthermore provided that is arranged to feed at least one web of paper and a predetermined conveying speed to said folding section.

3. The folding or interfolding machine according to claim 1, further comprising: a cutting, or perforating, section, arranged to cut, or perforate, said, or each, web of paper into a plurality of sheets of predetermined length.

4. The folding or interfolding machine according to claim 1, further comprising: a cutting, or perforating, section arranged to cut, or perforate, said, or each, web of paper into a plurality of sheets of predetermined length; a transfer section arranged to transfer to said folding, or interfolding, section said plurality of sheets.

5. The folding or interfolding machine according to claim 4, wherein said transfer section comprises at least one transfer roller provided with holding members arranged to hold the cut sheets in said cutting section, and to directly transfer them to a folding, or interfolding, section.

6. The folding or interfolding machine according to claim 5, wherein said transfer section comprises, furthermore, at least a first and a second transfer belt, each transfer belt arranged to receive said sheets from said transfer roller, and to transfer them to a respective suction belt of the folding, or interfolding, section.

7. The folding or interfolding machine according to claim 1, wherein each suction belt provides a predetermined number of rows of through holes, wherein each row comprises a plurality of through holes.

8. The folding or interfolding machine according to claim 7, wherein the distance between two successive rows of through holes, namely the pitch of said rows of through holes, is substantially double the length of a panel of said sheets.

9. The folding or interfolding machine according to claim 1, wherein said first and second support provide a substantially circular cross section and said length of said, or each, peripheral suction groove is arranged to define a suction portion extending for a predetermined angular width set between 30 and 120.

10. The folding or interfolding machine according to claim 1, wherein each suction belt is a toothed belt comprising a plurality of teeth alternated to a plurality of recesses, said plurality of teeth and recesses arranged to engage with a respective plurality of recesses and protrusions made on the lateral surface of the respective support.

11. The folding or interfolding machine according to claim 1, wherein at least one portion of the surface of said, or each, support consists of an external surface of a bearing which is arranged to reduce the friction at contact points of said suction belt with said external surface of said bearing.

12. The folding or interfolding machine according to claim 1, wherein said, or each, peripheral suction groove is located at a respective protrusion of said lateral surface of said support.

13. The folding or interfolding machine according to claim 1, wherein each support comprises: a first suction group comprising at least one peripheral suction groove positioned at a predetermined distance from ends of said support, said first suction group defining a first suction portion on said surface of said support; a second suction group comprising at least one suction groove positioned at a different distance from ends of said support, with respect to said, or each, peripheral suction groove of said first group, said second suction group defining on said surface of said support a second suction portion different from said first suction portion, said first and second suction portions partially overlapped to each other.

14. The folding or interfolding machine according to claim 1, further comprising a storage housing wherein a plurality of suction belts can be stored having a different pitch, and a different distance between two successive rows of suction holes, said suction belts arranged to be selectively installed at said folding, or interfolding, section, in such a way to obtain panels of a length equal to a half of said pitch.

15. The folding or interfolding machine according to claim 1, wherein each of said supports is a fixed support.

16. A conveying unit of a web, or sheet, of paper, or similar products, arranged to transfer said web, or sheet, of paper, along a transfer direction of a paper converting machine, wherein said conveying unit comprises: a support having a lateral surface provided with at least one peripheral suction groove extending for a predetermined length, said, or each, peripheral suction groove pneumatically connected to an air suction system, in such a way to define a corresponding suction portion at the lateral surface of the respective support; a suction belt arranged to move along a closed trajectory comprising said suction portion, said suction belt configured to air-tightly engage with said suction portion and providing at least one through hole arranged to be positioned at a respective suction portion in order to cause a suction effect on said web, or sheet, and to transfer it from a first point to a second point of a production line of paper products, or linear products obtained starting from said web, or sheet; a driving device configured to move said suction belt with respect to said support.

17. The conveying unit, according to claim 16, wherein at least one portion of the surface of said support consists of the external surface of a bearing which is arranged to reduce the friction at contact points of said suction belt with said external surface of said bearing.

18. The conveying unit, according to claim 16, wherein said support comprises: a first suction group comprising at least one peripheral suction groove arranged at a predetermined distance from ends of said support, said first suction group defining a first suction portion on said surface of said support; a second suction group comprising at least one suction groove positioned at a different distance from ends of said support, with respect to said, or each, peripheral suction groove of said first group, said second suction group defining on said surface of said support a second suction portion different from said first suction portion, said first and second suction portions partially overlapped to each other.

19. The conveying unit according to claim 16, wherein each said support is a fixed support.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further characteristics and the advantages of the invention will be made clearer with the following description of some exemplary embodiments thereof, exemplifying but not limitative, with reference to the attached drawings, in which:

(2) FIG. 1 diagrammatically shows in a perspective side view a first embodiment of a conveying unit, according to the invention, of a web, or sheet of paper in a paper converting machine;

(3) FIGS. 2, 4, 5, 6 and 10 show in perspective side views, some possible alternative embodiments of the conveying unit of FIG. 1;

(4) FIG. 3A diagrammatically shows a cross section along arrows III-III of the conveying unit of FIG. 2;

(5) FIG. 3B diagrammatically shows a cross section along arrows III-III of an alternative embodiment of the conveying unit of FIGS. 2 and 3A;

(6) FIG. 7 shows a partial cross section of the conveying unit of FIG. 6;

(7) FIGS. 8, 9A, 9B and 10 diagrammatically show some possible embodiments of the support used in the conveying unit, according to the present invention;

(8) FIG. 11 shows a perspective side view of another embodiment of the conveying unit according to the invention;

(9) FIG. 12 shows a partial cross section of another embodiment of the conveying unit provided by the invention;

(10) FIG. 13 shows a perspective side view of still another embodiment of the conveying unit according to the invention;

(11) Figs. from 14 to 16 diagrammatically show some embodiments of the machine for holding the paper using the transfer unit according to the invention in the folding, or interfolding, section.

DESCRIPTION OF A PREFERRED EXEMPLARY EMBODIMENT

(12) With reference to FIGS. 1 and 2, a conveying unit 100 of a web 5, or sheet 11, of paper is provided that is arranged to transfer along a transfer direction 110 (see FIG. 2) web 5, or sheet 11, of paper, and comprises at least one support 41 having a lateral surface 42 provided with at least one peripheral suction groove 43 extending for a predetermined length. The, or each, peripheral suction groove 43 is pneumatically connected to an air suction system 150, in such a way to define a corresponding suction portion 44 on lateral surface 42. In particular, suction system 150, which comprises, for example, a vacuum pump, is pneumatically connected to a suction chamber 160, in particular housed in support 41.

(13) Device 100, according to the invention, comprises, furthermore, a suction belt 45 arranged to move along a closed trajectory 46 comprising suction portion 44. More in detail, suction belt 45 provides at least one through hole 47, arranged to be positioned at a respective suction groove 43 for causing a suction on web 5, or sheet 11, and for transferring it from a first point P1 to a second point P2 of a paper converting machine 1 (FIGS. 15 and 16). Conveying unit 100 comprises, furthermore, a driving device 60 comprising, for example, a motor and a determined number of transmission members, arranged to move belt 45 with respect to support 41. In particular, a predetermined number of pulleys 70 can be provided, by means of which the above described trajectory is defined.

(14) Suction belt 45 is, generally, equipped with a predetermined number of rows of through holes 47. For example, in the embodiment of FIG. 1, suction belt 45 has a single hole 47 and support 41 has a single peripheral groove 43. In particular, in the case of a folding unit 40 equipped with the conveying unit, according to the invention, each belt 45a, 45b advantageously provides at least two holes.

(15) In general, however, suction belt 45 can provide at least a first and a second suction hole 47 and 47 positioned at a predetermined distance from each other, and arranged to selectively cause a suction effect on web 5, or the sheet of paper 11 (FIG. 4). More precisely, the distance between two suction holes 47 and 47 corresponds, in the case of a conveying unit, to the length of the sheets 11 that are processed by the machine 1, or, in the case of a folding unit, to the double of the length of the panels 12 of the sheets 11 (FIG. 14). In a further possible embodiment, belt 45 provides a plurality of rows of holes, each row of holes comprising a plurality of holes, for example two rows of holes, each comprising two holes 47a, 47b and 47a, 47b (like FIG. 5). In general, the distance between two rows of successive holes is substantially equal to the length of the sheet. Instead, when two conveying units 100 are provided, in order to be symmetric, at the folding section 40, the distance between two successive rows of holes 47 of each belt 45a and 45b is equal to the double of the panel length 12.

(16) In the alternative embodiment of FIG. 6, each row of holes comprises three holes 47a, 47b and 47c. In particular, the number of holes for each row of holes is chosen on the basis of the width of support 41, or according to another specific need of the process.

(17) In FIGS. 8, 9A, and 9B, some possible embodiments for support 41 are shown. More in detail, in the embodiment of FIG. 8, support 41 has a substantially circular cross section, whereas in the alternative embodiment of FIG. 9A, support 41 has a cross section, which comprises some rectilinear portions and some curvilinear portions. At one end, in the alternative embodiment of FIG. 9B, the cross section of support 41 is exclusively formed by rectilinear portions, connected, if necessary, by a curvilinear edge, in order to avoid feather-edges. In general, therefore, support 41 can have substantially any shape.

(18) As shown in detail, for example in FIGS. 3A, 3B and 7, suction belt 45 can be a toothed belt, i.e. it provides a plurality of teeth 55 alternated to a plurality of recesses 56.

(19) More precisely, the plurality of teeth 55 of belt 45 is arranged to engage with a corresponding plurality of recesses 53 made on lateral surface 42 of support 41. Analogously, each recess 56 of belt 45 is arranged to engage with a corresponding protrusion 52 of lateral surface 42 of support 41.

(20) As shown in FIG. 3A, the, or each, hole 47 can be made at least at a recess 56. In this case the, or each, peripheral groove 43 is made at the protrusion 52 that is arranged to engage the recess 56 of belt 45.

(21) In the example of FIG. 3B, instead, the, or each, hole 47 is made at least at a protrusion 55 of belt 45. In this case the, or each, peripheral groove 43 is, therefore, made at the recess 53 that is arranged to engage the protrusion 55 of belt 45. As shown in FIG. 7, it can be also provided that holes 47 are made both at one, or more, protrusions 55 and at one, or more, recesses 56 of belt 45.

(22) As diagrammatically shown in FIG. 12, at least one portion 42 of the surface 42 of support 41 can be the external surface of a bearing 80. In this way, at contact points of suction belt 45 with bearing 80, the friction is reduced substantially to zero. Notwithstanding in FIG. 12 bearings 80 are shown positioned at recesses 53, i.e. in contact with the surface of the teeth 55 of belt 45, they can also be positioned at the protrusions 52 of support 41, solution not shown for simplicity.

(23) As shown in detail in FIGS. 8 and 9, the, or each, peripheral suction groove 43 extends for a length to define a suction portion 49 under a predetermined angular width , for example set between 30 and 120. The shape of support 41, under angle , is shown as curvilinear, in particular circular, in FIGS. 8 and 9A, and as rectilinear in FIG. 9B, even though it could have a different shape, or it could be formed by a determined number of consecutive rectilinear segments.

(24) In the alternative embodiment of FIGS. 10 and 11, support 41 can provide a first suction group 143 comprising at least one peripheral suction groove 43 positioned at a predetermined distance from the opposite ends 61 and 62 of support 41. More in detail, the first group of suction grooves 43 defines, on the surface of support 41, a first suction portion 44. It is, then, provided a second suction group 143 comprising at least one suction groove 43 positioned at a different distance from ends 61 and 62 of the support, with respect to the peripheral suction groove 43 of the first group.

(25) The first and the second suction group define on the surface 42, respective different, but partially overlapped to each other, suction portions 44 and 44 (FIG. 10).

(26) In the case shown, for simplicity, in FIG. 11, support 41 has a substantially circular cross section. In this case, the peripheral grooves 43 of the first group and the peripheral grooves 43 of the second group are positioned at different circumferences. More in detail, the peripheral grooves 43 of the first group are arranged to cause a suction effect on web 5, or sheet 11, on the surface 42 of support 41 at the portion of the latter corresponding to a central angle (see FIG. 10), whereas the peripheral grooves 43 of the second group are arranged to cause a suction effect on web 5, or sheet 11, for holding the same on surface 42 of support 41, at a portion corresponding to an central angle . As shown in detail in FIG. 11, holes 47 of a row are shifted with respect to the holes 47a of the other row, i.e. they are positioned on belt 45 along different directions 85a-85d, and, furthermore, alternated to each other. The distance between holes 47 and 47a is about one panel length 12. In FIG. 11, a single row of holes 47, and a single row of holes 47a, are shown, even if it is clear that, since the distance between a row of holes 47 and the row of holes 47a is about one panel length and this distance is repeated the same for all the belt, further holes are provided on the belt which are not shown for simplicity.

(27) In FIG. 13 another alternative embodiment of the conveying unit 100 according to the invention is diagrammatically shown. In this case, the conveying unit comprises a plurality of supports 41, as above described, arranged coaxially to each other, in particular on a same support shaft. On each support 41 a respective belt 45 is arranged, as described with reference to FIGS. 1 to 12. The number of supports 41 and, therefore, of suction belts 45, that are used will depend, in particular, from the width of web 5, or sheet 11. Therefore, in this case, each suction belt 45 will be capable of causing a suction effect on a respective portion of a same processed sheet 11, or web 5, of paper, or similar products.

(28) With reference to FIGS. 14 to 16, in an embodiment of the invention, a folding and stacking machine 1 comprises a folding, or interfolding, section, 40 arranged to form a stack 50 of folded or interfolded sheets. More precisely, the folding, or interfolding, section, 40 provides a first and a second support 41a and 41b, each of which associated to a respective suction belt 45a and 45b, with the characteristics above described with reference to FIGS. 1 to 13.

(29) More in detail, as well known, the folding, or interfolding, section 40, is arranged for folding, or interfolding, a web of paper 5, or a plurality of sheets of paper 11, into a plurality of panels 12, according to a predetermined folding, or interfolding, configuration.

(30) According to the invention, the folding, or interfolding, section, 40, in this case, comprises a first and a second support 41a and 41b facing each other at a central zone 140. With reference to what it is shown in FIGS. 1-13, and in FIGS. 14-16, the supports 41a and 41b have respective lateral surfaces 42a and 42b both provided with at least one peripheral suction groove 43a and 43b extending along the lateral surface for a predetermined length. More precisely, the, or each, peripheral suction groove 43a and 43b is pneumatically connected to an air suction system, for example comprising a vacuum pump 150, to define a corresponding suction portion 44a and 44b on lateral surface 42a and 42b of respective supports 41a and 41b. On each support 41a and 41b, a first and a second suction belt 45a and 45b is mounted arranged to move respectively along a first and a second closed trajectory 46a and 46b.

(31) More precisely, the first and the second closed trajectory comprise, respectively, the above described suction portions 44a and 44b of the first and the second support 41a and 41b. More precisely, each suction belt 45a and 45b provides at least one through hole 47a and 47b which are arranged to be positioned at a respective suction groove 43a and 43b for causing a suction on the processed web 5, or on sheets 11.

(32) The driving device 60 is arranged to move the belts 45a and 45b with respect to support 41a and 41b, respectively, in such a way that the through holes 47 of one, or the other, belt 45 are positioned at the central zone 140 shifted from each other. In this way, it is possible to cause a suction effect on the web, or the sheet, alternately, on the first, and on the second support 41a and 41b, for obtaining the desired folded or interfolded configuration.

(33) As shown in the schematic representation of FIGS. 14, 15 and 16, machine 1 can further comprise a feeding section 10a and 10b arranged to feed at least one web of paper, at a predetermined conveying speed. The feeding section 10a and 10b, for example comprising a first and a second counter-rotating rollers (FIG. 14), is capable of feeding the web of paper 5a and 5b, respectively, directly to the folding, or interfolding, section, 40.

(34) Between the feeding section 10a and 10b and the folding, or interfolding, section, 40, a perforating section 20a and 20b (FIG. 14), or alternatively, a cutting section 20a and 20b, can be provided. In FIGS. 15 and 16, the cutting section is diagrammatically represented with a block and is arranged to cause, in a known way, the cut of the webs of paper 5a and 5b into sheets 11 of desired length. The cutting section 20a and 20b, or the perforating section 20a and 20b, can feed the perforated web 5a, 5b, or the sheets 11, directly to the folding section 40 (FIG. 15). Alternatively, between the cutting section 20a, 20b, or perforating section 20a, 20b, a transfer section 30a and 30b can be provided, operating the transfer of the sheets 11 to the folding, or interfolding, section, 40 (FIGS. 14 and 16).

(35) More in detail, in the case of the cutting section 20a and 20b, the web of paper 5a and 5b is directly divided into a plurality of sheets 11.

(36) Instead, in the case of the perforating section 20a and 20b, the web of paper 5a and 5b is perforated along the perforation lines. The perforated web 5a and 5b is, then, divided into sheets 11, in the transfer section 30a and 30b, which is positioned downstream of the perforating section 20a and 20b, in a known way and, therefore, not described in detail.

(37) In the examples of FIGS. 14, 15 and 16, the folding machine 100 is shown using the suction belts 45, as described with reference to FIG. 11. Notwithstanding the above, the folding machine 100 can provide, in general, any of the embodiments shown in Figs. from 1 to 13.

(38) The foregoing description of specific exemplary embodiments will so fully reveal the invention according to the conceptual point of view, so that others, by applying current knowledge, will be able to modify and/or adapt in various applications the specific exemplary embodiments without further research and without parting from the invention, and, then it is meant that such adaptations and modifications will have to be considered as equivalent to the specific embodiments. The means and the materials to realise the different functions described herein could have a different nature without, for this reason, departing from the field of the invention. It is to be understood that the phraseology or terminology that is employed herein is for the purpose of description and not of limitation.