Folding, or interfolding, unit for folding, or interfolding sheets of paper for a machine for paper converting
11629029 · 2023-04-18
Assignee
Inventors
Cpc classification
B65H45/24
PERFORMING OPERATIONS; TRANSPORTING
B65H45/28
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
A folding, or interfolding, unit, for folding, or interfolding, a first and a second plurality of sheets of paper in a machine for converting paper, comprises a first and a second folding, or interfolding, counter-rotating rolls configured to rotate about a respective longitudinal rotational axis and providing a plurality of suction holes. A vacuum generation device and a vacuum distribution device are, furthermore, provided for selectively putting into pneumatic communication the vacuum generation device with at least a row of the aforementioned suction holes. The folding, or interfolding, unit, comprises, furthermore, a first and a second cutting device providing, respectively, at least a first and a second cutting blade which cooperates with a first and a second plurality of counter-blades distributed along the folding, or interfolding rolls in order to cut a first and a second web of paper, in the first and in the second plurality of sheets.
Claims
1. A folding, or interfolding, unit, for folding, or interfolding a first and a second plurality of sheets of paper of a predetermined length and arranged to be folded, or interfolded, at a predetermined folding, or interfolding, zone, of a machine for converting paper, or similar product, said folding, or interfolding, unit comprising: first and second folding, or interfolding, counter-rotating rolls between which said folding, or interfolding, zone is defined, each said first and second folding, or interfolding, rolls, providing: a tubular body configured to rotate about a respective longitudinal rotational axis, and a plurality of suction holes being provided organized according to a predetermined number of longitudinal rows close to each other; a vacuum generation device configured to produce a predetermined vacuum degree; a vacuum distribution device configured to selectively put into pneumatic communication said vacuum generation device with at least a row of said plurality of rows of suction holes, at predetermined angular positions of said tubular body, in such a way to cause said plurality of processed sheets of paper to be sucked and to adhere at predetermined portions of said first, or second, folding, or interfolding, roll; a separation unit arranged to operate downstream of said folding, or interfolding, unit, said separation unit comprising a first and a second plurality of separator members configured to enter from opposite sides in a finished stack of folding, or interfolding, sheets, and to separate the same from a following forming stack of folded, or interfolded, sheets; a displacement unit configured to move said first plurality of separator members and said second plurality of separator members; a first and a second cutting device respectively associated to said first and to said second folding, or interfolding, roll said first and second cutting device, providing, respectively, at least a first and a second cutting blade, wherein: each said first and second folding, or interfolding, roll provides, respectively, a first and a second plurality of counter-blades distributed along said respective tubular body and configured to operate, respectively, in combination with said first and second cutting blades to divide a first and a second web of paper, or similar product, in said first and said second plurality of sheets, and said displacement unit is configured to move said first and second plurality of separator members between a first position and a second position along a respective displacement trajectory positioned outside the encumbrance of said first and second folding, or interfolding, rolls during the formation of said stack of folded, or interfolded, sheets in such a way not to intersect said first and second plurality of counter-blades.
2. The folding, or interfolding, unit, according to claim 1, wherein said first and second tubular bodies provide, furthermore, a first and a second plurality of recesses alternated, respectively, to said first and second plurality of counter-blades, said first and second folding, or interfolding, rolls being configured in such a way that, at said folding, or interfolding, zone, a counter-blade of said first, or second, plurality of counter-blades is arranged to engage a respective recess of said second, or first, plurality of recesses.
3. The folding, or interfolding, unit, according to claim 2, wherein said first and second plurality of counter-blades are positioned, respectively, on said first, and said second, tubular body at predetermined angular positions in such a way to be positioned at a constant angular distance.
4. The folding, or interfolding, unit, according to claim 2, wherein each said vacuum distribution device is configured to suck said first, or said second, plurality of sheets of paper, at a first suction portion positioned downstream of said cutting device and to suck said first, or said second, web of paper on said first, or said second, folding, or interfolding, roll at a second suction portion positioned upstream of said first, or second, cutting device.
5. The folding, or interfolding, unit, according to claim 4, wherein said first and second plurality of counter-blades are positioned, respectively, on said first, and said second, tubular body at predetermined angular positions in such a way to be positioned at a constant angular distance.
6. The folding, or interfolding, unit, according to claim 4, wherein said first and second plurality of counter-blades are positioned, respectively, on said first, and said second, tubular body at an angular distance of 120° one with respect to the other.
7. The folding, or interfolding, unit, according to claim 2, wherein said first and second plurality of counter-blades are positioned, respectively, on said first, and said second, tubular body at an angular distance of 120° one with respect to the other.
8. The folding, or interfolding, unit, according to claim 2, wherein each counter-blade of said first and said second plurality of counter-blades is positioned between two suction holes of the same couple of suction holes close to each other.
9. A machine for converting paper, or similar product, comprising the folding, or interfolding, unit, according to claim 2.
10. The folding, or interfolding, unit, according to claim 1, wherein each said vacuum distribution device is configured to suck said first, or said second, plurality of sheets of paper, at a first suction portion positioned downstream of said cutting device and to suck said first, or said second, web of paper on said first, or said second, folding, or interfolding, roll at a second suction portion positioned upstream of said first, or second, cutting device.
11. The folding, or interfolding, unit, according to claim 10, wherein said first and second plurality of counter-blades are positioned, respectively, on said first, and said second, tubular body at predetermined angular positions in such a way to be positioned at a constant angular distance.
12. The folding, or interfolding, unit, according to claim 1, wherein said first and second plurality of counter-blades are positioned, respectively, on said first, and said second, tubular body at predetermined angular positions in such a way to be positioned at a constant angular distance.
13. The folding, interfolding, unit, according to claim 1, wherein said first and second plurality of counter-blades are positioned, respectively, on said first, and said second, tubular body at an angular distance of 120° one with respect to the other.
14. The folding, or interfolding, unit, according to claim 1, wherein each counter-blade of said first and said second plurality of counter-blades is positioned between two suction holes of the same couple of suction holes close to each other.
15. A machine for converting paper, or similar product, comprising the folding, or interfolding, unit, according to claim 1.
16. The machine for converting paper, or similar product, according to claim 15, wherein a removing unit is, furthermore, provided comprising a first plurality of removing members, and a second plurality of removing members, configured to act, respectively, at said first and second folding, or interfolding, rolls to remove said sheets from the respective folding, or interfolding, roll.
17. The machine for converting paper, or similar product, according to claim 16, wherein said removing members have a geometry such that non interfere with said plurality of counter-blades during said movement carried out by said displacing device.
18. The machine for converting paper, or similar product according to claim 17, wherein said removing members are substantially “S”-shaped, or substantially “Z”-shaped.
19. The machine for converting paper, or similar product according to claim 16, wherein said removing members are substantially “S”-shaped, or substantially “Z”-shaped.
20. A method for folding, or interfolding, a first and a second plurality of sheets of paper comprising the steps of: feeding a first and a second web of paper, respectively, along a first and a second advancing direction; folding, or interfolding, said first and said second plurality of sheets of paper at a predetermined folding, or interfolding, zone, of a machine for converting paper, or similar product, said folding, or interfolding step being carried out by a first and a second folding, or interfolding, counter-rotating rolls between which said folding, or interfolding, zone is defined, each of said first and second folding, or interfolding, rolls (1a,1b), providing: a tubular body configured to rotate about a respective longitudinal rotational axis, and providing a plurality of suction holes organized according to a predetermined number of couples of longitudinal rows close to each other; a vacuum generation device configured to produce a predetermined vacuum degree; and a vacuum distribution device configured to selectively put into pneumatic communication said vacuum generation device with at least a row of suction holes of said plurality, at predetermined angular positions of said tubular body, in such a way to cause said plurality of processed sheets of paper to be sucked at predetermined portions of said first, or second, folding, or interfolding, roll; and separating downstream of said folding, or interfolding, unit, of a finished stack of folded, or interfolded, sheets from a following forming stack of folded, or interfolded, sheets by a first and a second plurality of separator members configured to enter from opposite sides with respect to said finished stack and said forming stack, wherein: said method being characterized in that said first and said second folding, or interfolding, rolls are, respectively, associated to a first and to a second cutting device that are, respectively, provided of at least a first and a second cutting blade; said first and second folding, or interfolding, roll provides, respectively, a first and a second plurality of counter-blades distributed along said respective tubular body and configured to operate, respectively, in combination with said first and second cutting blades to divide a first and a second web of paper, or similar product, in said first and second plurality of sheets; and said separating step of said finished stack (150a) from said following forming stack is carried out by moving said first and second plurality of separator members between a first position and a second position along a respective displacement trajectory positioned outside the encumbrance of said first and second folding, or interfolding, roll in such a way not to intersect said first and second plurality of counter-blades.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The invention will now be shown with the following description of its exemplary embodiments, exemplifying but not limitative, with reference to the attached drawings in which:
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
DETAILED DESCRIPTION OF SOME EXEMPLARY EMBODIMENTS OF THE INVENTION
(10) In
(11) In an embodiment of the invention, each vacuum distribution device 40a, or 40b can provide a longitudinal cavity, the position of which, in figure, is diagrammatically shown with a broken line, provided within the tubular body 10a, or 10b. More in particular, the longitudinal cavity 40a, or 40b, can be permanently connected with the rows of suction holes 11a, 12a, 11b, 12b, but selectively connected to the vacuum generation device. In other words, the suction in the longitudinal cavity 40a, or 40b, of tubular body 10a, or 10b, and, therefore, in the rows of holes 11a, or 11b, or 12a, or 12b, can be activated only at determined angular positions of the holes. This result can be, for example, obtained by electro-valves, or by lateral suction sectors which provides to connect the vacuum generation device to the longitudinal cavity 40a, or 40b, of tubular body 10a, or 10b, only in predetermined angular positions. Advantageously, the aforementioned lateral suction sectors can be bell vacuum distributors arranged coaxially at an end of the tubular body 10a, or 10b. In particular, each bell vacuum distributor develops coaxially to the tubular body 10a, or 10b, and is, preferably, fixed. Therefore, during the rotation of the tubular body 10a, or 10b, zones, or sectors, are formed at which the holes 11a, or 11b, or 12a, or 12b, sucks and, therefore, keep at least a sheet 105a, or 105b, on the surface of the respective tubular body 10a, or 10b, and, instead, other zones, or sectors, at which no suction is carried out.
(12) Alternatively to the aforementioned technical solution, as diagrammatically shown in
(13) Furthermore, according to the invention, as diagrammatically shown in
(14) As shown, for example in
(15) According to the present invention, the folding, or interfolding, unit, 100, furthermore, comprises, a first and a second cutting device 60a, 60b, respectively, associated to the first and to the second folding, or interfolding, roll 1a, 1b. More precisely, the first and the second cutting device 60a and 60b can provide, respectively, at least a first and a second cutting blade 65a, or 65b, for example mounted on a respective, preferably fixed, support body 61a, or 61b.
(16) More in detail, the first and the second folding, or interfolding, rolls 1a, or 1b, provide, respectively, a first and a second plurality of counter-blades 5a and 5b, distributed on the respective tubular body 10a and 10b. The counter-blades 5a and 5b are configured to operate, respectively, in combination with the first and the second cutting blades 65a and 65b, in order to divide a first and a second web of paper 101a and 101b, that are fed along a first and a second feeding direction 111a and 111b, in the aforementioned first and second plurality of sheets 105a and 105b, of predetermined length. In a particular configuration, as shown, for example, in
(17) In the embodiments according to the invention that are diagrammatically shown in
(18) Advantageously, the first and the second plurality of counter-blades 5a and 5b, are positioned, respectively, on the first, and on the second, tubular body 10a and 10b, at predetermined angular positions such to be positioned at a constant angular distance. For example, on each roll 1a, or 1b3, can be provided counter-blades 5a and 5b, which are positioned at angular positions such that the central angle between two successive angular positions is equal to 120°. The possibility is also provided that the number of counter-blades 5a and 5b on each roll 1a and 1b can be, however, greater than 3, for example equal to 6. In this case, the central angle between two successive angular positions is equal to 60°.
(19) In the embodiment diagrammatically shown in the
(20) In the preferred alternative embodiment shown in the
(21) Preferably, each counter-blade 5a, or 5b, of the first, or the second, plurality of counter-blades is positioned between two suction holes of the same couple of suction holes close to each other (see at this regard the enlargements depicted in the
(22) In
(23) The machine 200 can advantageously, furthermore, provide a removing unit comprising a first plurality of removing members 85a, and a second plurality of removing members 85b, or removing fingers, configured to act, respectively, at the first and the second folding roll 1a and 1b to remove the sheets from the respective folding, or interfolding, roll 1a, or 1b. More precisely, the first and the second plurality of removing members 85a and 85b and the folding rolls 1a and 1b are, advantageously, displaced in phase from each other in such a way to, alternately, advance laterally towards sheet 105a, or 105b, and to move away the same from the respective roll 1a, or 1b, thus, causing the sheet same to be removed from the surface of the roll to which it adheres, without, anyway, interfering with the aforementioned counter-blades 6a, or 6b.
(24) In some particularly advantageous embodiments of the invention, the phase between the removing members 85a and 85b and the folding, or interfolding, rolls 1a and 1b can be mechanically carried out. More in particular, each removing member 85a and 85b can be moved from an internal position to a respective groove, that is not shown in the figures for simplicity, provided in the folding rolls 1a and 1b, to a position external to the folding rolls 1a and 1b same, in such a way to cause the sheets 105a, 105b to be “detached” from the respective folding rolls 1a and 1b. With the expression “mechanical phase” it is to be intended that the removing members 85a and 85b and the folding rolls 1a and 1b are mechanically connected to each other, in particular by gears and/or cams, in particular desmodromic cams, and/or pulleys actuated by the same motor, or by different motors in phase from one another, that means such that are able to give the same law of motion to the kinematic mechanism.
(25) According to a particular embodiment of the invention, the removing members 85a and 85b can have a geometry such that they do not interfere with the plurality of counter-blades 5a and 5b of rolls 1a and 1b. For example, as diagrammatically shown in
(26) In particular, still as diagrammatically shown in
(27) As diagrammatically shown in the two snapshots depicted in the
(28) The displacement unit 90 can be electronically in phase with the folding, or interfolding, rolls 1a and 1b and with the removing members 85a and 85b. In this case, kinematic connection mechanisms between the different components are not provided. The actuation of the displacement unit 90 is, advantageously, operated by an electronic control unit configured to detect, during the cycle of the machine, the instant in which the separator members 80a and 80b have to be inserted in the stack of folding, or interfolding, sheets.
(29) In a further alternative embodiment of the invention also the displacement unit 90 can be mechanically in phase with the other parts of the folding machine. In this case, the change of the length of the stack can be, advantageously, carried out by stopping the machine and modifying the part of the machine adjusting the phase between the displacement unit 90 and the other parts of the folding machine.
(30) Advantageously, in a further alternative embodiment of the invention that is not shown for simplicity, the folding, or interfolding, machine providing of the folding, or interfolding, unit, as above described with reference to
(31) The foregoing description exemplary embodiments of the invention 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 for various applications such embodiment without further research and without parting from the invention, and, accordingly, it is therefore to be understood that such adaptations and modifications will have to be considered as equivalent to the specific embodiments. The means and the materials to realize 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.