Suction roller for sheet-shaped products

Abstract

A suction roller (1) for sheet-like products comprises a fixed tubular body (10) provided with an outer side surface (11) and an inner side surface (12) defining a longitudinal suction chamber (16). Furthermore, the rotating tubular body (20) is arranged to be coaxially mounted to the fixed tubular body (10) for rotation about the longitudinal axis of rotation (120). The rotating tubular body (20) is provided with at least a first and a second plurality of suction channels (23, 24) arranged in respective predetermined number of longitudinal rows (3, 4). Furthermore, a device (50) for generating an air flow is provided for generating the air flow at a defined pressure in the longitudinal suction chamber (16). The fixed tubular body (10) is provided with a first and a second plurality of circumferential apertures (15a, 15b) distributed along a first and a second longitudinal direction (13, 14), respectively. Each circumferential orifice (15a, 15b) is positioned along a respective circumferential portion of the fixed tubular body (10) to pneumatically connect the longitudinal suction chamber (16) with at least one row (23, 24) of the first and second plurality of suction channels (23, 24), respectively, at a predetermined angular position of the rotating tubular body (20).

Description

Technical Field

[0001] This invention relates to the field of paper processing and similar products, and more particularly, to a suction roller (e.g., a forward roller, a cutting roller, a folding or staggered folding roller for a machine for staggered folding of paper webs or sheets), such a suction roller having suction holes connected to a vacuum system, allowing paper sheets or webs to adhere to the surface of the suction roller.

[0002] Furthermore, the present invention relates to a paper converting machine that includes at least such suction rollers. Background Technology

[0003] As is well known, many machines used in the paper industry (such as rewinders, staggered folders, and folding machines) are equipped with systems that adsorb the paper web or sheet being processed onto the surface of the rolls in a defined working step so as to feed the paper sheet or web along a desired path.

[0004] Specifically, the system is used to perform basic operations such as cutting paper, transferring paper very quickly from one roller to another, or performing a final fold on the paper itself.

[0005] In recent years, suction rollers equipped with pneumatic systems have been widely developed in the field of paper processing machinery, enabling the paper sheets or webs being processed to adhere to a defined portion of the outer surface of the suction roller. More specifically, as described in EP1457444 or EP2514698, such suction systems provide a device for generating a defined vacuum level, which is pneumatically connected to the interior of the suction roller. More specifically, such suction rollers include a rotating tubular body adapted to rotate about a longitudinal axis of rotation and a fixed tubular body coaxial with and located inside the rotating tubular body. The surface of the rotating tubular body is provided with a defined number of paired longitudinal rows (typically 3 or 4 rows) of suction holes. Additionally, the fixed tubular body is provided with longitudinal rows of orifices. A vacuum distribution device is provided between the rotating tubular body and the fixed tubular body, comprising first and second sealing elements or gaskets arranged longitudinally at two different angular positions relative to the suction roller and positioned on opposite sides relative to the aforementioned rows of orifices of the fixed tubular body. In this way, the inner surface of the rotating tubular body, the outer surface of the fixed tubular body, and the longitudinal sealing element form a suction chamber.

[0006] During the rotation of the rotating tubular body relative to the fixed tubular body, the aforementioned multiple rows of holes are selectively pneumatically connected to the device that generates a vacuum from the vacuum distribution device. More specifically, the holes of the rotating roller, positioned only between the two sealing elements at predetermined times, exert a suction effect on the processed paper sheet or web, causing it to adhere to the corresponding portion of the outer surface of the suction roller.

[0007] However, these types of suction rollers have some drawbacks.

[0008] Specifically, paper processing machines typically have more than one suction roll, each guided to perform a defined operation in the production cycle. For example, folding or staggered folding machines generally have a cutting roll, one or more transfer rolls, and a pair of folding or staggered folding rolls. The different suction rolls of the machine are usually connected to the same vacuum generating device (e.g., a vacuum pump) via a series of pipes. Therefore, although pressure drops are inevitable along the suction lines, their dimensions must be designed to ensure a defined vacuum level within all suction rolls. Furthermore, these suction lines provide a series of valves for isolating or isolating the vacuum in different parts of the machine (especially the different suction rolls) to allow maintenance or replacement of each suction roll to be performed without disassembling the entire pipeline or adjusting the vacuum level to better suit the machine. This means a further concentrated pressure drop along the vacuum suction lines and a longer settling time required during the machine's start-up configuration phase.

[0009] In light of the above, it is necessary to increase the size of the device used to generate the vacuum to compensate for the aforementioned pressure drop and ensure the suction effect of different rollers. However, this implies high costs for the device and its operation, particularly due to the high power consumption of the vacuum generating device and the cost of the generator itself.

[0010] In addition to the above, during the operation of the suction roller, dust and material debris (especially paper debris) present in the environment surrounding the suction roller and generated during the working cycle are inevitably sucked up by the suction lines. Over time, this can lead to partial blockage of at least the suction orifices and the pipes connecting the vacuum generating device to different dispensing devices, thus causing a loss of effectiveness in the suction system, which inevitably results in a loss of quality in the final product. Therefore, known types of suction rollers must be regularly maintained and repaired to clean the different components that make up the suction roller. Maintenance and repair require the disassembly of all connections (usually flange connections) that hold the roller itself together. Then, several pipes, which can be tens of meters long, are disassembled to allow for cleaning, and after cleaning, these pipes are reconnected to each other and to each suction roller.

[0011] The same procedure is performed for routine maintenance and overhauls that involve replacing the sealing elements on a scheduled basis. In fact, the sealing elements will wear down over time due to friction generated as the rotating tubular body rotates around its longitudinal axis and due to the dragging of the sealing elements on the inner surface of the rotating tubular body.

[0012] Therefore, in view of the above, whether in the case of maintenance for cleaning several components of the suction roller or in the case of maintenance for replacing sealing elements, the maintenance and repair of the suction roller of the prior art is complex and extremely expensive in terms of manpower, cost and time.

[0013] Examples of suction rollers with the aforementioned drawbacks are described in EP3781506, US2004 / 250706, and US10294058. Summary of the Invention

[0014] Therefore, the object of the present invention is to provide a suction roller for a paper processing machine that overcomes the shortcomings of rollers in the prior art.

[0015] Specifically, one object of the present invention is to provide a suction roller for a paper processing machine that simplifies and accelerates ordinary and extraordinary maintenance and repairs, particularly the replacement of the provided gaskets.

[0016] These and other objectives are achieved by a suction roller that draws the sheet-like product to advance it in a forward direction, the suction roller comprising: A fixed tubular body is provided with an outer surface and an inner surface that defines a longitudinal suction chamber; A rotating tubular body, coaxially mounted to the fixed tubular body, has an outer surface and an inner surface, and is configured to rotate about a longitudinal axis of rotation outside the fixed tubular body. The rotating tubular body is provided with at least a first plurality of suction channels and a second plurality of suction channels arranged in a corresponding predetermined number of longitudinal rows. The device for generating an airflow is arranged to generate an airflow at a defined pressure in the longitudinal suction chamber; The main feature of the suction roller is that the fixed tubular body is provided with a first plurality of circumferential orifices and a second plurality of circumferential orifices respectively distributed along a first longitudinal direction and a second longitudinal direction, and each of the first plurality of circumferential orifices and the second plurality of circumferential orifices is arranged along a corresponding circumferential portion of the fixed tubular body so as to dynamically connect the longitudinal suction chamber with at least one row of the first plurality of suction channels and the second plurality of suction channels at a predetermined angular position of the rotating tubular body.

[0017] Other features and related embodiments of the invention are set forth in the dependent claims.

[0018] Specifically, the first plurality of circumferential orifices and the second plurality of circumferential orifices can be positioned on corresponding circumferential portions of the fixed tubular body and are circumferentially staggered relative to each other. In this way, the first and second rows of suction channels can be pneumatically connected to the longitudinal suction chamber at the aforementioned predetermined angular positions of the rotating tubular body.

[0019] In one embodiment of the invention, the device for generating an airflow has a body integral with the fixed tubular body. More specifically, the device for generating an airflow further includes an impeller adapted to be housed within the body and operatively connected to a motor to generate the airflow in the longitudinal suction chamber. In an advantageous embodiment, the device for generating an airflow is configured to generate an airflow at a predetermined pressure (Pi) below atmospheric pressure.

[0020] Specifically, the rotating tubular body may also be provided with at least a third plurality of suction channels arranged in a predetermined number of longitudinal rows. More specifically, the longitudinal rows or each longitudinal row of the first plurality of suction channels and the second plurality of suction channels may be positioned on the rotating tubular body to be pneumatically connected to the first plurality of circumferential orifices at the corresponding angular positions, while the longitudinal rows or each longitudinal row of the third plurality of suction channels may be positioned on the rotating tubular body to be pneumatically connected to the second plurality of circumferential orifices at the corresponding predetermined angular positions.

[0021] In one embodiment of the present invention, the first plurality of suction channels and the second plurality of suction channels may be arranged in multiple suction groups on multiple rows circumferentially to the rotating tubular body. Specifically, each of the aforementioned plurality of suction groups may include at least a first suction channel from the first plurality of suction channels and at least a second suction channel from the second plurality of suction channels separated by partition walls.

[0022] Specifically, the cross-section passage of each of the aforementioned first and second plurality of suction channels increases from the inner surface of the rotating tubular body toward the outer surface at least a portion of its length.

[0023] Similarly, the cross-sectional passage of each of the aforementioned third plurality of suction channels increases from the inner surface of the rotating tubular body toward the outer surface at least along a portion of its length.

[0024] Specifically, the first and second longitudinal rows of the fixed tubular body have first and second plurality of circumferential orifices having corresponding circumferential portions arranged side by side along the longitudinal direction.

[0025] According to another aspect of the invention, a suction roller for sheet-like products is configured to advance the sheet-like products along a forward direction, the suction roller comprising: A fixed tubular body is provided with an outer surface and an inner surface that defines a longitudinal suction chamber; A rotating tubular body is coaxially mounted to the fixed tubular body, has an outer surface and an inner surface, and is configured to rotate about a longitudinal axis of rotation outside the fixed tubular body. The rotating tubular body is provided with at least a first plurality of suction channels and a second plurality of suction channels arranged in a predetermined number of longitudinal rows. The device for generating an airflow is arranged to generate an airflow at a defined pressure in the longitudinal suction chamber; The fixed tubular body is provided with a first plurality of circumferential orifices and a second plurality of circumferential orifices respectively distributed along a first longitudinal direction and a second longitudinal direction, and each of the first plurality of circumferential orifices and the second plurality of circumferential orifices is arranged along a corresponding circumferential portion of the fixed tubular body so as to dynamically connect the longitudinal suction chamber to at least one of the first plurality of suction channels and the second plurality of suction channels at a predetermined angular position of the rotating tubular body.

[0026] According to another aspect of the invention, the paper processing machine includes at least one processing unit selected from: Folding or staggered folding unit, which is adapted to fold or stagger webs or multiple sheets made of sheet material (especially paper) according to a predetermined folding or staggered folding configuration; The cutting unit is configured to cut a continuous web made of sheet material into multiple sheets of predetermined length; The forward unit is arranged to advance the paper web or sheet along a predetermined forward direction; Or a combination of the above units; The processing unit or each processing unit includes at least one suction roller as described above. Attached Figure Description

[0027] The invention will now be described with reference to the accompanying drawings, by way of the following description of exemplary embodiments thereof, which are exemplary and not restrictive, wherein: Figure 1 A perspective side view of a first embodiment of the fixed tubular body of the suction roller according to the present invention is shown schematically. Figure 2 A perspective side view of a first embodiment of the suction roller according to the present invention is shown schematically; Figure 3 and Figure 4 schematically shown Figure 2The suction roller has two different longitudinal sections; Figure 5 and Figure 6 schematically shown Figure 2 The suction roller has two different transverse sections; Figure 7 schematically shows Figure 2 The longitudinal section of an alternative embodiment of the suction roller; Figure 8 An enlarged view of a portion of Figure 7 is shown schematically to highlight some technical features; Figure 9 and Figure 10 Two different transverse sections of the suction roller in Figure 7 are schematically shown; Figure 11 The alternative is shown schematically. Figure 1 A perspective side view of an embodiment of a fixed tubular body; Figure 12 and Figure 13 schematically shown Figure 2 A perspective side view of two possible alternative embodiments of the suction roller; Figure 14 It shows Figure 13 A magnified view of a portion to highlight certain technical features; Figure 15 Another alternative embodiment of the suction roller according to the invention is shown; Figure 16 The illustration schematically shows a possible embodiment of a suction assembly that can be used with the suction rollers according to the invention in an engaged configuration; Figure 17 The image shown is cut off according to arrows XVII-XVII. Figure 16 Cross-sectional view of the suction assembly; Figure 18 The schematic diagram shows the state of being out of configuration. Figure 16 The suction unit; Figure 19 An auxiliary suction assembly that can be used by the suction roller according to the invention is schematically shown; Figure 20 and Figure 21 schematically shown Figure 15 Two different transverse sections of the suction roller; Figures 22 to 24 A side view schematically illustrates a further embodiment of the suction roller according to the invention; Figure 25 A perspective side view of a fixed tubular body according to another embodiment of the present invention is shown schematically. Detailed Implementation

[0028] like Figure 1The suction roller 1 according to the invention, schematically shown, is of the type used, particularly in paper processing machines or similar products, to feed sheet-like products (e.g., paper webs or sheets) along a forward direction. The suction roller 1 includes a fixed tubular body 10 having an outer surface 11 and an inner surface 12 defining a longitudinal suction chamber 16. Furthermore, the suction roller 1 is provided with a rotating tubular body 20 coaxially mounted to the fixed tubular body 10 and configured to rotate about a longitudinal axis of rotation 120 outside the fixed tubular body 10. The rotating tubular body 20 has an outer surface 21 and an inner surface 22. Specifically, as... Figure 3 and Figure 4 As schematically shown, a device that allows the first to rotate relative to the second, such as a bearing 85 or a brass, can be installed between the rotating tubular body 20 and the fixed tubular body 10.

[0029] The rotating tubular body 20 is provided with at least a first plurality of suction channels 23 and a second plurality of suction channels 24 arranged in corresponding predetermined numbers of longitudinal rows 3 and 4. Figures 1 to 3 In the schematically illustrated embodiment, the rotating tubular body 20 is provided with multiple rows of first plurality of suction channels 23, 3a and 3b, wherein in Figure 2 You can see the first two rows 3a and 3b, and the second multiple suction channels 24, including multiple rows 4a and 4b. Figure 2 You can see the first two rows, 4a and 4b.

[0030] In addition, a device 50 for generating an airflow is provided, which is configured to generate an airflow at a predetermined pressure (particularly less than atmospheric pressure) within the longitudinal suction chamber 16.

[0031] The fixed tubular body 10 is also provided with a first plurality of circumferential apertures 15a and a second plurality of circumferential apertures 15b respectively distributed along a first longitudinal direction 13 and a second longitudinal direction 14. Specifically, each of the first plurality of circumferential apertures (or curved apertures) 15a and 15b of the second plurality of circumferential apertures is positioned along the corresponding circumferential portion of the fixed tubular body 10 so as to pneumatically connect the longitudinal suction chamber 16 to at least one row 3 and 4 of the first plurality of suction channels 23 and the second plurality of suction channels 24 at a predetermined angular position of the rotating tubular body 20.

[0032] Specifically, the first plurality of circumferential orifices 15a and the second plurality of circumferential orifices 15b are located on the corresponding circumferential portions of the fixed tubular body 10. More specifically, each of the first plurality of circumferential orifices (or arcuate orifices) 15a may be positioned close to the corresponding circumferential orifice (or arcuate orifice) 15b in the second plurality of circumferential orifices, for example, at a distance between 1 mm and 150 mm, advantageously between 1.5 mm and 100 mm, preferably between 1.5 mm and 50 mm, for example, between 2 mm and 50 mm.

[0033] More specifically, the aforementioned circumferential portion can extend between two identical generatrices 101 and 102 of the rotating tubular body 20, such as... Figure 1 The embodiment is shown schematically. In other words, the first plurality of circumferential orifices 15a and the second plurality of circumferential orifices 15b of the fixed tubular body 10 can be distributed on the first longitudinal row 13 and the second longitudinal row 14 which are arranged circumferentially side by side or substantially side by side in the longitudinal direction.

[0034] In contrast, as will be described in detail below, in Figure 11 In an alternative embodiment, the aforementioned circumferential portions with circumferential openings 15a and 15b are arranged to be circumferentially staggered. Specifically, as... Figure 11 As shown, the circumferential portions with circumferential openings 15a and 15b can partially overlap each other. Specifically, as... Figure 11 As schematically shown, the first plurality of circumferential orifices 15a and the second plurality of circumferential orifices 15b of the first longitudinal row 13 and the second longitudinal row 14 of the fixed tubular body 10 have corresponding circumferential portions 17a and 17b arranged side by side along the longitudinal direction. More specifically, along a certain number of generatrices of the cylindrical body of the fixed tubular body 10, both circumferential portions 17a and circumferential portions 17b meet. In contrast, along other generatrices, only circumferential orifices 15a meet, or only circumferential orifices 15b meet.

[0035] For example, such as Figure 22 As schematically shown, the device 50 for generating airflow may include a body 51 on which an impeller 52 may be mounted, as schematically shown in the figure. The impeller 52 may be operatively connected to a motor 56 to cause rotation about a rotation axis.

[0036] The device 50 for generating airflow can be pneumatically connected to the aforementioned longitudinal suction chamber 16 via at least one conduit 60, or it can be integrally mounted to the fixed tubular body 10 (see...). Figure 23 In both cases, the device 50 for generating the airflow is arranged to generate a defined airflow 55 in the longitudinal suction chamber 16 at a predetermined pressure (Pi) (preferably, a pressure less than atmospheric pressure).

[0037] Specifically, the device 50 for generating airflow is configured to move the airflow between the inlet 16a and the outlet 16b through the longitudinal suction chamber 16 provided by the fixed tubular body 10. More specifically, the aforementioned device 50 for generating airflow can be selected from a fan (preferably a centrifugal fan) and a compressor (preferably a centrifugal compressor).

[0038] For example in Figure 12 As schematically shown in the embodiments, the rotating tubular body 20 may also be provided with at least a third plurality of suction channels 25 arranged in a corresponding predetermined number of longitudinal rows. Specifically, the aforementioned third plurality of suction channels 25 can be used for folding sheets or webs of sheet-like materials, such as paper or cardboard, but may also be nonwoven fabrics and similar materials. For example, as Figure 20 The illustration shows one embodiment of the invention, but it can also be applied to another alternative embodiment described herein. The suction channels 23 and 24 of the first plurality of suction channels and the second plurality of suction channels can be used to each suction of the head or part of the head 6 and the tail or part of the tail 7 of the sheet 5 of the sheet material, in particular for moving it downstream of the cutting section (not shown in the figure for simplicity).

[0039] In a pre-defined embodiment, the first plurality of suction channels and the longitudinal rows or each longitudinal row of suction channels 23 and 24 of the second plurality of suction channels can be positioned on the rotating tubular body 20 and pneumatically connected to the first plurality of circumferential orifices 15a at the aforementioned corresponding predetermined angular positions. Conversely, the longitudinal rows or each longitudinal row of suction channels 25 of the third plurality of suction orifice channels can be positioned on the rotating tubular body 20 to pneumatically connect to the second plurality of circumferential orifices 15b at the corresponding predetermined angular positions. For example, as described above, the first plurality of suction channels 23 and the second plurality of suction channels 24 can be adapted to suction the head and tail of a sheet of sheet material (especially paper) onto the surface 21 of the rotating tubular body 20, and the third plurality of suction channels 25 can be adapted to suction the sheet at the central portion 8 of the sheet, particularly allowing the suction roller 1 to cooperate with a second suction roller 1 rotating in the opposite direction to it to perform folding or staggered folding at folding or staggered folding points.

[0040] In the preset of the present invention and Figures 12 to 21 In the schematically illustrated embodiment, the first plurality of suction channels 23 and the second plurality of suction channels 24 can be arranged as a plurality of suction groups 30. These suction groups can be arranged circumferentially on multiple rows 36 of the rotating tubular body 20. Specifically, each suction group 30 includes a first suction channel 23 of the first plurality of suction channels and a second suction channel 24 of the second plurality of suction channels separated by a partition wall 27.

[0041] In another embodiment, a fourth plurality of suction channels 26 are also provided, arranged in at least one row longitudinally to the rotating tubular body 20. In an embodiment according to the invention, each suction assembly 30 may be an insertion member arranged to engage with the rotating tubular body 20 at a corresponding seat. The suction channels 26 may also participate in the suction step of the central portion 8 of the sheet 5.

[0042] In the presence of the aforementioned fourth or more suction channels 26, a second or more suction groups 30' can be set up. Specifically, for example, Figure 19 As schematically shown, each of the second plurality of suction groups 30' may include at least one suction channel 25 of a third plurality of suction channels and at least one suction channel 26 of a fourth plurality of suction channels separated from each other by partition walls 27'.

[0043] Specifically, the longitudinal rows of the first suction group 30 and the second suction group 30' can preferably be alternately positioned on the rotating tubular body 20.

[0044] like Figure 23 As schematically shown, at least one pressure sensor 80 may also be provided, arranged to detect the pressure within the longitudinal suction chamber 16. Specifically, this pressure sensor, or each pressure sensor 80, may be arranged to send a corresponding pressure signal P(ti) to a control unit 300, which is arranged to operate the aforementioned device 50 for generating airflow. More specifically, the control unit 300 may be arranged to adjust the device 50 for generating airflow based on the received pressure signal P(ti), and particularly by acting on a motor 56 provided for this purpose. In this way, the airflow 55 can be increased or decreased to increase or decrease the pressure P(ti) within the longitudinal suction chamber 16, making it equal to a predetermined pressure value P. Or, in any way, make it related to pressure P The difference is less than the predetermined deviation value ΔP That is, ׀P(ti)-P ׀≤ΔP .

[0045] For example, Figure 3 , Figure 4 , Figure 8 and Figures 17 to 19As shown, advantageously, from the inner surface 22 to the outer surface 21 of the rotating tubular body 20, the cross-sectional passage of each of the first plurality of suction channels 23 and the second plurality of suction channels 24 increases at least a portion of its length. Advantageously, each of the first plurality of suction channels 23 and 24, and each of the third plurality of suction channels 25 and 26 (if present) is associated with a corresponding protective member 40. Specifically, this may be provided with a plurality of holes 41, the size of which prevents the processed sheet material (particularly paper webs or sheets) from entering the suction channels 23, 24, and similarly into the suction channels 25 and 26 (if present), while simultaneously allowing the product to be drawn to adhere at predetermined angular portions of the outer surface 21 of the rotating tubular body 20 at circumferential orifices 15a and 15b, so as to transfer it downstream of the suction roller 1 along the aforementioned direction of travel.

[0046] Specifically, such as Figures 16 to 19 As shown, each suction assembly 30 may include a hollow body 31, which is provided with a first suction channel 23 and a second suction channel 24. Figures 16 to 18 ), or the third suction channel 25 and the fourth suction channel 26 ( Figure 19 ).

[0047] Specifically, each suction assembly 30 can be associated with a corresponding protective member 40, which advantageously has a plurality of holes 41. The protective member 40 can be configured, particularly relative to the hollow body 31, from an engaging configuration ( Figure 16 and Figure 17 Move to disengagement configuration ( Figure 18 and Figure 19 For example, through a connector that can be disassembled by screws, bolts, or similar connecting elements (not shown in the figures for simplicity). In this way, according to the invention, the protective member 40 can be removed when necessary, or during planned maintenance of routine upkeep, to access the hollow body 31 and thus perform cleaning and maintenance of the suction channels 23, 24, 25, and 26 to remove dust and debris from the processed product that inevitably passes through the suction channels during machine operation equipped with the suction roller or each suction roller 1 according to the invention. Specifically, in use, each hollow body 31 is accommodated in a corresponding seat 28 provided on the rotating tubular body 20.

[0048] More specifically, the protective member 40 is provided with the aforementioned plurality of holes 41. These are adapted to pneumatically connect each suction channel 23, 24, 25 and 26 to the outer surface 21 of the rotating tubular body 20. Advantageously, the inlet openings 23a, 24a, 25a and 26a of the suction channels are smaller than the outlet openings 23b, 24b, 25b and 26b.

[0049] like Figure 18 In the embodiment shown schematically, the protective member 40 may have a longitudinal lower portion 45. In this way, under working conditions, it is possible to avoid obstructing the movement of the cutting blade (if present, but not shown in the figure for simplicity), which is located downstream of the suction roller 1, to cut a continuous web made of sheet material into multiple sheets of predetermined lengths.

[0050] like Figures 1 to 25 As schematically shown, each suction channel 23, 24, 25 and 26 is configured to extend longitudinally into the rotating tubular body 20.

[0051] Similarly, each circumferential orifice 15a and 15b can be configured to extend longitudinally into the fixed tubular body 10.

[0052] exist Figure 24 In the schematically illustrated embodiment, a cover member 70 is provided, suitable for positioning at the inlet 16a of the longitudinal suction chamber 16. Specifically, the cover member 70 may have a passage opening 71 through which airflow 55 enters the longitudinal chamber 16 being drawn by the device 50 for generating airflow, and may also include an adjustment assembly 77 to increase or decrease the cross-sectional area of ​​the passage opening 71. For example, as... Figure 24 As shown, the adjustment assembly 77 may include a series of movable elements 75 adapted to engage in corresponding guides 76, move in a guided manner, and increase or decrease the cross-section of the passage opening 71 as needed.

[0053] exist Figure 25 In another alternative embodiment, which is schematically shown, the fixed tubular body 10 may advantageously be provided with an annular portion 18 between the circumferential orifice 15a (or 15b) and the immediately following circumferential orifice 15a (or 15b), the annular portion 18 being adapted to pneumatically separate the two.

[0054] The suction roller 1 described above can be installed in the processing unit of a paper processing machine.

[0055] Specifically, at least a first suction roller and a second suction roller 1, which rotate in opposite directions relative to each other, can be installed at a folding or staggering folding unit configured to fold or stagger webs or multiple sheets according to a predetermined folding or staggering folding configuration.

[0056] As described above, the suction roller 1 can also be installed at the cutting unit, which is configured to cut a continuous web made of sheet material into multiple sheets so that they move downstream of the aforementioned cutting unit.

[0057] In one predetermined embodiment, as described above, the suction roller 1 may be mounted on a forward unit configured to advance the paper web or sheet along a predetermined forward direction.

[0058] The foregoing description of specific embodiments fully discloses the invention from the inventive concept, enabling others to modify and / or adapt various applications of such embodiments by applying present knowledge without further research and without departing from the invention. Therefore, it should be understood that such adaptations and modifications must be considered equivalents of the specific embodiments. Consequently, apparatus and materials for implementing the different functions described herein may have different properties without departing from the scope of the invention. It should be understood that the wording or terminology used herein is for descriptive purposes and not for limitation.

Claims

1. A suction roller (1) for suctioning a sheet-like product to advance the sheet-like product along a forward direction, the suction roller (1) comprising: The fixed tubular body (10) has an outer surface (11) and an inner surface (12) defining a longitudinal suction chamber (16). A rotating tubular body (20) is coaxially mounted to the fixed tubular body (10), has an outer surface (21) and an inner surface (22), and is configured to rotate about a longitudinal axis of rotation (120) outside the fixed tubular body (10). The rotating tubular body (20) is provided with at least a first plurality of suction channels (23) and a second plurality of suction channels (24) arranged in a corresponding predetermined number of longitudinal rows (3, 4). The device (50) for generating an airflow is arranged to generate an airflow at a defined pressure in the longitudinal suction chamber (16); The suction roller (1) is characterized in that the fixed tubular body (10) is provided with a first plurality of circumferential orifices (15a) and a second plurality of circumferential orifices (15b) distributed along a first longitudinal direction (13) and a second longitudinal direction (14), and each of the first plurality of circumferential orifices (15a, 15b) and the second plurality of circumferential orifices (15b) is arranged along the corresponding circumferential portion of the fixed tubular body (10) so as to pneumatically connect the longitudinal suction chamber (16) to at least one row (23, 24) of the first plurality of suction channels (23) and the second plurality of suction channels (24) at a predetermined angular position of the rotating tubular body (20).

2. The suction roller (1) according to claim 1, wherein the first plurality of circumferential orifices (15a) and the second plurality of circumferential orifices (15b) are located on the corresponding circumferential portions of the fixed tubular body (10) and are circumferentially staggered with each other.

3. The suction roller (1) according to claim 1, wherein the device (50) for generating an airflow is provided with a body (51) integral with the fixed tubular body (10), and an impeller (52) is housed in the body (51) and operatively connected to a motor (56) to rotate about a rotation axis, thereby generating a defined airflow in the longitudinal suction chamber (16).

4. The suction roller (1) according to any one of the preceding claims, wherein the rotating tubular body (20) is further provided with at least a third plurality of suction channels (25) arranged in a corresponding predetermined number of longitudinal rows (5), wherein the first plurality of suction channels and each longitudinal row of the second plurality of suction channels are positioned on the rotating tubular body (20) to be pneumatically connected to the first plurality of circumferential orifices (15a) at the corresponding angular positions, and the third plurality of suction channels are positioned on the rotating tubular body to be pneumatically connected to the second plurality of circumferential orifices (15b) at the corresponding predetermined angular positions.

5. The suction roller (1) according to any one of the preceding claims, wherein the first plurality of suction channels (23) and the second plurality of suction channels (24) are arranged in a plurality of suction groups (30), the plurality of suction groups being arranged longitudinally on multiple rows (36) of the rotating tubular body (20), each of the plurality of suction groups (30) including a first suction channel (23) of the first plurality of suction channels and a second suction channel (24) of the second plurality of suction channels separated by a partition wall (27).

6. The suction roller (1) according to any one of the preceding claims, wherein at least one pressure sensor (80) is provided, the at least one pressure sensor being arranged to detect the pressure in the longitudinal suction chamber (16) and send a corresponding pressure signal (P(ti)) to a control unit (300), the control unit being arranged to control the device (50) for generating airflow according to the pressure signal (P(ti)).

7. The suction roller (1) according to any one of the preceding claims, wherein the cross-sectional passage of each of the first plurality of suction channels (23) and the second plurality of suction channels (24) increases from the inner surface (22) to the outer surface (21) of the rotating tubular body (20).

8. The suction roller (1) according to claim 1, wherein the first plurality of circumferential orifices (15a) and the second plurality of circumferential orifices (15b) of the first longitudinal row (13) and the second longitudinal row (14) of the fixed tubular body (10) have corresponding circumferential portions (17a, 17b) arranged side by side in the longitudinal direction.

9. The suction roller (1) according to any one of the preceding claims, wherein the device (50) for generating airflow is a centrifugal compressor or a centrifugal fan, the centrifugal compressor or centrifugal fan having a body (51) integral with the fixed tubular body (10) and configured to house an impeller (52) arranged to rotate about a rotation axis substantially coaxial with the fixed tubular body (10) and operated by a motor (56).

10. The suction roller (1) according to any one of claims 5 to 9, wherein each of the plurality of suction groups (30) is associated with a corresponding protective member (40) having a plurality of holes (41) sized to prevent the sheet-like product being processed from entering the suction channels (23, 24) and at the same time allowing the sheet-like product being processed to be suctioned to adsorb onto the predetermined angle portion of the outer surface (21) of the rotating tubular body (20).

11. The suction roller (1) according to any one of the preceding claims, further comprising a cover member (70) arranged to be positioned at the inlet (16a) of the longitudinal suction chamber (16), the cover member (70) having a passage opening (71) through which the airflow is arranged to enter the longitudinal suction chamber (16) being drawn by the means (50) for generating the airflow, and wherein, An adjustment group (77) is also provided, which is adapted to increase or decrease the cross-sectional area of ​​the passage opening (71).

12. The suction roller (1) according to claims 3 and 6, wherein the control unit (300) is arranged to act on the motor (56) of the device (50) for generating airflow to adjust the airflow (55) to increase or decrease the pressure P(ti) in the longitudinal suction chamber (16) such that the pressure is equal to a predetermined value P. , or with the predetermined value P The difference is less than the predetermined deviation value ΔP .

13. The suction roller (1) according to one or more of the preceding claims, wherein the suction channels (23, 24) of the first plurality of suction channels and the second plurality of suction channels are respectively used to suction a portion of the head portion and a portion of the tail portion of the sheet (5) of the sheet material.

14. The suction roller (1) according to claim 5, wherein each suction assembly (30) includes a hollow body (31) having the first suction channel (23) and the second suction channel (24), wherein in use each hollow body (31) is accommodated in a corresponding seat (28) provided in the rotating tubular body (20).

15. The suction roller (1) according to claims 10 and 14, wherein the protective member (40) is configured to move from an engaging configuration to a disengaged configuration relative to the hollow body (31).

16. The suction roller (1) according to one or more of the preceding claims, wherein each of the first plurality of circumferential orifices or arcuate orifices (15a) is located at a distance of 1 mm to 150 mm from the corresponding circumferential orifice or arcuate orifice (15b) in the second plurality of circumferential orifices.

17. A paper processing machine comprising a folding or staggering folding unit arranged to fold or stagger a sheet product according to a predetermined folding or staggering folding configuration, the sheet product being particularly a web or multiple sheets, the paper processing machine being characterized in that the folding or staggering folding unit comprises at least one suction roller according to any one of claims 1 to 16.

18. The paper processing machine according to claims 4 and 17, wherein the suction channel (25) of the third plurality of suction channels is used to suction the central portion (8) of the sheet (5) of the sheet material.

19. A paper processing machine, comprising at least one processing unit, said processing unit being selected from: Folding or staggered folding units are arranged to fold or stagger sheet products according to a predetermined folding or staggered folding configuration, said sheet products being particularly webs or multiple sheets; The cutting unit is configured to cut a continuous web made of sheet material into multiple sheets; A forward unit is arranged to advance a sheet-like product along a predetermined forward direction, the sheet-like product being, in particular, a paper web or sheet. Or a combination of the above units; The paper processing machine is characterized in that the at least one processing unit includes at least one suction roller according to any one of claims 1 to 16.

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