Compliant system with fin

Abstract

To provide a compliant system with fin which is a system (1) for transporting a web (2).SOLUTION: A system includes a center element (11) extending along a vertical axis (AA'), and at least one fin (12) or a pair of fins arranged around the vertical axis.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a roller system for web processing, in particular a roller system designed to guide a web, and also to a roller system for transporting a web. The invention finally relates to a method for transporting a web using such a roller system. [Background technology]

[0002] In various applications it is necessary to guide the web along a set of rollers. Especially in the application of web converting, lateral shifts or off-tracking of the web can cause defects at different stages. Corrections of the web position can be necessary to ensure the processing of the returning web, especially when high speeds and / or thin films are used.

[0003] To solve this problem, US2989265 describes a web handling system that includes two tubes with shafts driven by bracket arms. One limitation of such a solution is its obstruction and the use of two guide members.

[0004] US3326435 B1 describes two cylinders freely rotating about their axis of rotation to compensate for misalignment of the flat web. However, the first limitation of this solution is that it requires at least two cylinders and a means of changing the axis of rotation of the two cylinders (pistons, hydraulic cylinders, energy sources, sliding couplings, etc.), which increases the volume and complexity of the entire system.

[0005] US8554354 describes a method for adaptively guiding a web on a roller. One limitation of this method is the use of electronics and computerized systems. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] US2989265 [Patent Document 2] US3326435 B1 [Patent Document 3] US8554354 Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, there is a need for a new system that allows for self-centering of the web in high speed conversion or manufacturing processes that overcomes the cited limitations.

[0008] Furthermore, wrinkles can occur during handling of thin webs. This causes the problem of creases appearing on the web. Therefore, in order to transport the web without defects, it is necessary to guide the web along a set of rollers. To avoid creases, wrinkles or multiple creases at different stages, especially when high speeds and / or thin films are used.

[0009] There is also a need for new systems that overcome the cited limitations to smoothly self-unfold webs in high speed converting or manufacturing processes. [Means for solving the problem]

[0010] The present invention relates to a system for transporting a web, the system comprising a central element extending along a longitudinal axis and at least one fin or set of fins arranged about the longitudinal axis, preferably on a surface of the central element, each fin of the fin or set of fins including a first transverse portion separated from a second transverse portion by a plane perpendicular to the longitudinal axis and including an outer surface supporting the web along at least the first and second transverse portions.

[0011] In one embodiment, the fin or each fin in the set of fins is movable between three positions: a first position, a second position, and a third position.

[0012] In one embodiment, in the first position, the contour of the outer surface is symmetrical about a plane.

[0013] In one embodiment, in the second position, a first distance between an outer surface of the first lateral portion of the fin and the longitudinal axis is less than a second distance between an outer surface of the second lateral portion and the longitudinal axis.

[0014] In one embodiment, in the third position, a second distance between an outer surface of the second lateral portion of the fin and the longitudinal axis is less than a first distance between an outer surface of the first lateral portion and the longitudinal axis.

[0015] The second or third position is obtained by tilting the fin along its rotational degree of freedom along the longitudinal axis.

[0016] The fin or each fin of the set of fins is configured to move from a first position to a second position or a third position when a pressure distribution applied by the web to the outer surface is higher in the first portion than in the second portion or higher in the second portion than the first portion, respectively.

[0017] According to another aspect, the invention relates to a roller system for transporting a web, the roller system including a central roller rotating along (around) a longitudinal axis of the central roller and a set of fins arranged around the longitudinal axis.

[0018] Each fin in the set of fins includes an outer surface for supporting the web, the outer surface defining a first lateral portion of the fin and a second lateral portion of the fin separated from the first lateral portion of the fin by a plane perpendicular to the longitudinal axis. In one embodiment, each fin in the set of fins is movable between three positions:

[0019] A first position in which the contour of the outer surface is symmetrical (preferably in a radial plane) with respect to a plane perpendicular to the longitudinal axis. A second position where a first distance between the first lateral portion and the longitudinal axis is less than a second distance between the second lateral portion and the longitudinal axis. A third location where the second distance is less than the first distance.

[0020] In one embodiment, the fins are configured to move from the first position to the second position or the third position when the distribution of pressure exerted by the web on the exterior surface is higher in the first portion than in the second portion, or higher in the second portion than in the first portion. In other words, the fins are configured to move from the first position to the second position or the third position when the total force exerted by the web is higher in the first lateral portion or the second lateral portion of the surface, respectively.

[0021] In one embodiment, each fin is mechanically connected to the central roller by a mechanical link, and each fin is configured to tilt about the mechanical link to move from a first position to a second or third position.

[0022] In one embodiment, the mechanical link includes a pivot connection, preferably an axial pivot connection between the fins and the central roller.

[0023] In one embodiment, the mechanical link between the fin and the central roller comprises a joint that includes at least one tapered portion.

[0024] In one embodiment, the junction between the central roller and the fin includes a thin central portion, a first tapered portion that decreases in thickness from the fin to the thin central portion, and a second tapered portion that decreases in thickness from the central roller to the thin central portion.

[0025] In one embodiment, in the second or third position, a second axis perpendicular to the outer surface and passing through the mechanical connection is inclined at an angle strictly less than 90° relative to the longitudinal axis.

[0026] In one embodiment, each fin is removably connected to the central roller.

[0027] In one embodiment, at least one fin includes a perforated outer surface.

[0028] In one embodiment, each side of the fin is movable closer to the longitudinal axis when pressure is applied to its outer surface.

[0029] In one embodiment, the central roller and the fins are one unique monoblock element.

[0030] In one embodiment, the contour of the outer surface of the fin comprises a concave profile.

[0031] In one embodiment, the contour of the exterior surface of the fin comprises a convex profile.

[0032] According to another aspect, the invention also relates to a system for conveying a web including a support element having a first surface and at least one fin disposed on the first surface, each fin including a first lateral portion separated from a second lateral portion by a plane perpendicular to the first surface and an outer surface supporting the web at least along the first and second lateral portions.

[0033] In one embodiment, the support element is mechanically fixed to the frame with 0 rotational degrees of freedom and preferably 0 translational degrees of freedom. In one embodiment, the support element or system is removable from the frame. In one embodiment, the at least one fin is movable between at least three positions: The first position where the outer surface profile is symmetrical about a plane. A second position where a first distance between the first lateral portion and the first surface is less than a second distance between the second lateral portion and the first surface. A third location where the second distance is less than the first distance.

[0034] The second or third position is obtained by tilting the fin along its rotational degree of freedom about the longitudinal axis.

[0035] The fins are configured to move from a first position to a second position or a third position when a distribution of pressure exerted by the webs on the outer surface is higher in the first portion than in the second portion or higher in the second portion than in the first portion. In other words, the fins are configured to move from a first position to a second position or a third position under the effect of a total force exerted by the webs when the total force exerted by the webs is higher in the first lateral portion or the second lateral portion of the surface, respectively. According to another aspect, the present invention provides a roller system for transporting a web, the roller system comprising: a central roller rotating about its longitudinal axis; a set of fins arranged about a longitudinal axis, each fin having two opposing lateral portions; Equipped with Each lateral portion of each fin is movable such that a first distance between one lateral portion and the longitudinal axis is less than or greater than a second distance between the opposing lateral portion and the longitudinal axis.

[0036] In one embodiment, each fin of the set of fins includes an outer surface for supporting the web, the outer surface defining a first lateral portion of the fin and a second lateral portion of the fin, the second lateral portion separated from the first lateral portion by a plane perpendicular to the longitudinal axis. According to another aspect, the present invention provides a system for transporting a web, the system comprising: a support element having a first surface; at least one fin disposed on the first surface and having two opposing lateral portions; Each lateral portion of the fin is movable such that a first distance between the lateral portion and a first surface is less than or greater than a second distance between the opposing lateral portion and the first surface.

[0037] According to another aspect, the invention also relates to a transport system comprising a number of rollers for transporting a web along a predetermined path and at least one roller system according to the invention and / or a system according to the invention.

[0038] According to another aspect, the invention relates to a method of transporting a web comprising providing a transport system and a web according to the invention, rotating at least one roller of the transport system to move the web along a predetermined path, the method further comprising using fins to move the web along the predetermined path and automatically correcting for web misalignment. [Brief description of the drawings]

[0039] [Figure 1] 1 is a schematic cross-sectional view of a portion of a roller system according to an embodiment of the present invention;

[0040] [Figure 2A] 2 is a schematic cross-sectional view of the roller system shown in FIG. 1 when the fin is in a first engagement position.

[0041] [Figure 2B] 2 is a schematic cross-sectional view of the roller system shown in FIG. 1 when the fin is in a first engagement position.

[0042] [Diagram 3] 2 is a schematic cross-sectional view of the roller system shown in FIG. 1, taken along a plane perpendicular to the longitudinal axis of said roller system;

[0043] [Figure 4] FIG. 1 is a schematic perspective view of a roller system according to one embodiment of the present invention.

[0044] [Diagram 5] FIG. 5 is a cross-sectional view of the roller system shown in FIG.

[0045] [Figure 6]FIG. 2 is a cross-sectional view of a connection between a central roller and a fin according to one embodiment of the present invention.

[0046] [Figure 7] 1 is a schematic diagram of a transport system for transporting an endless ribbon, comprising a roller system, according to an embodiment of the present invention;

[0047] [Figure 8] 4 is a graph illustrating edge position of a web on a roller system over time in accordance with one embodiment of the present invention.

[0048] [Figure 9] 1 is a schematic cross-sectional view of a portion of a roller system according to an embodiment of the present invention, in which the outer surface of the fin is concave in cross-section;

[0049] [Figure 10] 1 is a schematic cross-sectional view of a portion of a system according to one embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0050] In the converting process, the flat web tends to align perpendicular to the axis of rotation of the next roller. If at least one of the axes of the rollers in the transport system is not perfectly aligned with the others, the web tends to move and its width creates an angle with the machine direction (the "web roller misalignment angle" or "skew angle"). The web ends can become misaligned and create tension gradients across the web. This can result in defects, vibrations, and premature wear due to winding or unwinding. The present invention takes advantage of the tension variation across the web. An end with high tension causes the roller system on one side to back out. When the web tension is again balanced and the web ends regain their exact alignment with the machine direction, the roller system can recover its initial shape. The web straightens out again to feed the next roller with balanced tension and the web roller misalignment is cancelled.

[0051] The present invention relates to a roller system for transporting and guiding flat webs. The concept of the present invention relates to a roller initially formed as a cylinder with an adaptive geometry. If the pressure applied to the roller is a little more on one side, e.g. if the circulating web is about to go off-center or drift, the geometry of the roller is modified. The web tension across the width is then adjusted so that the center and the ends of the web are aligned in the machine direction. Thus, the geometry follows the imbalance of the web tension. The switch of the geometry is caused by the tilting or deformation of at least one fin arranged on the central roller. Industrially, the roller system can be installed anywhere where fine alignment or realignment of the web is required, including in the dryer.

[0052] The present invention advantageously provides a compact solution for web tension control and web guiding while avoiding the creation of skew angles between the web and the machine direction of said web. One advantage is that the web is conveyed and aligned without the need for external energy. Another advantage is that such a roller system can be used in explosive atmosphere environments. Another advantage lies in the phenomenon of double compensation of tension depending on the wrap angle on the roller system. The tilt of the fin depends on both the web tension induced by the upstream roller and the web tension induced by the downstream roller. The roller system is truly self-compensating for tension imbalances between the upstream and downstream rollers.

[0053] The present invention also provides accurate and reliable end alignment and unwind guidance when winding a web onto a spool, reel, beam, jumbo roll, roll, core, mandrel, etc. In other words, the roller system according to the present invention advantageously automatically laterally centers a web conveyed by said rollers when the web becomes laterally displaced or misaligned.

[0054] Ultimately, the present invention provides a solution that reduces downtime and waste in the conversion process.

[0055] definition As used herein, the following terms may be understood in accordance with their given definitions.

[0056] A "lateral portion" of a fin may be understood as a part of the fin that includes one longitudinal end of said fin.

[0057] A "roller system" may be understood as a roller system including at least one fin, preferably multiple fins arranged on or around a central roller and intended to guide and / or support a flat web.

[0058] "Web" or "flat web" refers to any film, foil, sheet, etc. whose length and / or width dimension is at least 10 or 100 times its thickness dimension. A web can include any long, thin, flexible structure (paper, film, foil, nonwoven, woven fabric, etc.).

[0059] "Machine direction" refers to the direction of travel of the web contacting the exterior surface of the fin.

[0060] The flat web may be a web of finite length, or a closed loop such as a band or any kind of endless film, ribbon, etc. The web may be a multi-layer stack.

[0061] The term "perceptually" followed by an angle value may be understood with values ​​of + / - 0.5° or + / - 1°. For example, "perceptually perpendicular" may be understood as "denoting an angle in the range of 89.5° to 90.5°."

[0062] As used herein, the terms "lateral" or "laterally" refer to the dimension parallel to the longitudinal axis AA' of the roller system.

[0063] As used herein, the terms "conveyor" or "conveyor" refer to any type of process in which a moving web may contact rotating rollers, such as, but not limited to, the transport or guidance of a web during a converting or manufacturing process.

[0064] Flat Web Optionally, the web exhibits a flat and / or flexible surface. The flat web can comprise any type of material, such as metal, glass, paper, cloth, leather, plastic, particles, etc., plain, laminated, or any combination. The flat web can be plain, rough, smooth, or open, such as a net. The flat web can comprise a polymer, such as polyester or polyimide. The flat web can be an aluminum or copper foil. The flat web can be coated or printed.

[0065] Preferably, the flat web is designed and / or intended to be coated, printed, chemically treated, cut, slit, sliced, rolled and / or unrolled, cured or dried. The other side, which is not coated, is intended to be in contact with the outer surface of the roller system. Flat webs may also result from shaped manufacturing processes such as cast or blown film extrusion.

[0066] Optionally, the flat web is a band. The roller system according to the invention is particularly advantageous for managing the alignment of an endless ribbon running along a path forming a loop. The flat web may be a drive belt. The flat web may be used to carry an object or to rotate an element.

[0067] The roller systems may be used to address web misalignment in the manufacturing industries of food containers, automotive and aircraft parts, furniture surfaces, bags, insulation, boxes, carpets, clothing, credit cards, flooring, magazines, currency, newspapers, siding, upholstery, wrapping, adhesive tape, food wrap, tape, tissue, etc. The roller systems may be used in the printing industry and within printers (electrophotographic, laser printing, thermal transfer printers, etc.).

[0068] Roller System A system according to the present invention includes a support and at least one fin movably connected to the support.

[0069] One embodiment of the present invention in which the support is a roller will now be described with reference to Figures 1 to 6.

[0070] The system 1 comprises a roller system, the support comprising a central roller 11 (also called "central roller" or "center roller" in the following description) having an axis of rotation AA'.

[0071] The central roller 11 preferably extends longitudinally along its axis of rotation AA' (also referred to herein as the "longitudinal axis").

[0072] A set of fins 12 are arranged around the longitudinal axis of the central roller, preferably on the central roller surface. The fins are distributed radially on the central roller surface. The fins 12 protrude upward from the central roller 11 to compensate for misalignment and correct position when the web tends to shift away (lateral shift) or angle off center (angular distortion). Such rollers are intended to reduce web off-tracking.

[0073] In one embodiment, the roller system is free to rotate, such as an idler roller. One advantage is that it guides the web after or before unwinding, acting as a displacement guide.

[0074] In another embodiment, the roller system is motorized. One advantage is that it provides traction from the web to the rollers.

[0075] The roller system includes a number of fins 12 radially distributed around a central roller 11. The roller system may include at least one fin. A flat web may run on an outer surface 15 of the fin. The roller system or parts of the roller system may include polymers, rubbers, ceramics, metals, etc.

[0076] The roller system can withstand high temperatures, speeds, tensions and loads. One advantage is the use of the roller system in any converting process, for example a process that includes a drying or curing step.

[0077] Center Roller The central roller 11 is preferably a roller having a cylindrical shape, such as a right circular cylinder. The cylinder may be plain or hollow. The longitudinal axis of said cylindrical shape is preferably the axis of rotation AA'.

[0078] The shape of the center roller is not limited to a right cylinder. The center roller can include a core, a mandrel, a core chuck, or a core center roller. The center roller can be a dead-of-life center roller.

[0079] One advantage of the central roller 11 is that it allows radial alignment of the fins 12 at a predetermined constant distance from the axis of rotation AA'.

[0080] In one embodiment, the stems of the fins may extend radially uniformly around the central roller, preferably around the circumference of the central roller, partway along its length, hi another embodiment, the central roller may include at least one fin.

[0081] In one embodiment, said central roller 11 comprises at its longitudinal ends coupling means which cooperate with complementary coupling means of the frame of the transport system. These coupling means are well known to those skilled in the art. In one embodiment, the coupling means comprise blind holes and complementary spindles and / or stators / rotors.

[0082] The central roller is designed to ensure both the rotation of the roller system about the axis of rotation AA′ and the support of the fin 12 .

[0083] In one embodiment, the roller system includes damping means to support the fin along its length. One advantage is to prevent vibration of the fin and web at high speeds. Preferably, the damping means includes foam or elastomeric material. Preferably, the damping means is located between the fin and the central roller. In one embodiment, the damping means includes stops to limit movement of the fin.

[0084] In one embodiment, the central roller is perforated and air (or any other gas) may be blown outward from its core towards the gaps between the fins. One advantage is that the fluid supports the web between each fin. The air blow may be circulated within the fins via mechanical links 13. The air blow may be transported using nozzles, hollow cables, or other means.

[0085] fin The fins 12 are arranged around a central roller 11. The outer surface 15 of each fin is intended to support a part of the web. The web may be supported by a part of the surface 15 of the fin. In other words, a part of the outer surface 15 of the fin or a part of the lateral part of the fin supports the web. The actual contact between the web and the outer surface 15 of the fin depends on the profile of the fin, the aspect of the surface (unevenness, presence or absence of indentations, notches, etc.), the elongation of the web, among other features. As a matter of fact, the part of the part towards the center may not be in full contact with the web, especially if the fin is designed with a concave profile or if the fin is curved, inclined or shaped along its circumference. If the web runs on an air cushion, the web may be supported by an equivalent part of the surface 15 of the fin.

[0086] In one embodiment, shown in FIG. 3, the roller system includes eight fins.

[0087] Preferably, as shown, each fin extends longitudinally along a direction generally parallel to the longitudinal axis AA' so as to cover the outer surface of the central roller along its length dimension.

[0088] Preferably, each fin extends longitudinally from both portions of the mechanical link 13 .

[0089] Preferably, the fins 12 are regularly spaced around the central roller 11 with spaces between each fin.

[0090] By "regularly arranged" it should be understood that the angular spacing Z between each adjacent fin 12 is identical or approximately equal around the longitudinal axis AA'. Preferably, the angular spacing Z between two adjacent fins 12 is equal or approximately equal to 360° / n, where n is the number of fins 12 arranged on the central roller 11.

[0091] The fins 12 extend longitudinally across the width of the web (i.e., the length dimension is at least five times longer than the width and thickness dimensions). Narrow fins advantageously modify the gap between the fins to tailor the contact area with the web, thus promoting or reducing grip or slippage depending on the type of web.

[0092] Additionally, the narrower the fins, the more fins there are. One advantage is that it allows for a higher density of fins around the central roller, increasing the center of the web on the fins, especially when the web reaches high speeds. Fin density also allows for an increased wrap angle (the overlap angle of the film on the roller), advantageously improving the center of the web on the fins. Fin density also allows for better management of the mechanical tension differentials upstream and downstream of the roller system.

[0093] In one embodiment, the thickness of the fin is constant along a direction parallel to the AA' axis. In another alternative embodiment, the lateral portions of the fin are thicker than the central portion. In one embodiment, the fin has a tapered portion along the AA' axis.

[0094] A cross-sectional view of one fin connected to a central roller 11 according to a plane containing the longitudinal axis AA' is shown in Figure 1. In one embodiment, the profile of the outer surface 15 of the fin in the plane containing the longitudinal axis AA' is straight or flat, although other profiles may be implemented. Preferably, the profile of the outer surface 15 comprises axial symmetry with respect to a second axis DD' passing through the center of gravity of the fin.

[0095] Each fin is mechanically connected to the central roller 11, preferably by a mechanical link 13. Preferably, the profile of the outer surface of the fin is axisymmetric about a second axis DD′ passing through the mechanical link 13.

[0096] In one embodiment shown in FIG. 9, the profile of the outer surface 15 of the fin in the plane containing the longitudinal axis AA' is concave. The concave shape of the outer surface of the fin allows the roller system to look macroscopically like a concave roller. Preferably, the profile of the outer surface of the fin is symmetrical with respect to a plane passing through the axis DD'. The concave profile can advantageously add other features to the roller system for processing the web. For example, such a concave profile can guide the web to spread across the roller to prevent wrinkles. The spreading of the web can also be promoted by gaps between each fin presenting a flat or curved outer surface. Another advantage is the prevention of the appearance of wrinkles in the web.

[0097] In another embodiment, the profile of the outer surface 15 of the fin in the plane containing the longitudinal axis AA is convex. One advantage is that when the web is located above a winding roller on which it can be stored, it is properly guided, avoiding air trapping in the coil and reducing downtime and waste.

[0098] In one embodiment, the fin surface is perforated to allow air (or other gas) to be blown under the web or to create an air outflow. The perforations include through holes extending from the outer surface and the opposite surface of the fin. One advantage is to control the contact between the web and the roller so as to enhance and / or facilitate guiding of the web by reducing or increasing slippage. Another advantage is to increase the speed of the web and reduce maintenance. Another advantage is to allow air flow to form an air cushion between the web and the outer surface, curving the web and reducing the risk of wrinkling the web. In one embodiment, the system comprises a means for adjusting the air flow to form an air cushion between the web and the outer surface. For example, the perforated surface comprises a gate for partially closing the perforations and a means for controlling the position of said gate. In a preferred embodiment, a space gap is managed between two adjacent fins. This space gap advantageously avoids the fins from hitting each other and brings the fins closer together when the fins are in the engaged position. This space gap can advantageously reduce air entrainment, air lifting, or air entrapment between the web and the roller. This can be used to facilitate the outgassing of air during winding. Depending on the characteristics of the web or the type of process involved, the number of fins, their thickness or chemical composition can be adapted. The performance of the inclination can be improved if the fin material is isotropic and the fins are symmetrical with respect to a plane perpendicular to the longitudinal axis AA'.

[0099] Each fin of the set of fins, or preferably the outer surface of each fin of the set of fins, includes a first transverse portion separated from a second transverse portion by a plane. The plane is perpendicular to the longitudinal axis AA'. Preferably, if there is only one mechanical link connecting the fin to the central roller, the plane passes through the mechanical link as described below.

[0100] The outer surface of the fin extends along at least both the first lateral portion and the second lateral portion.

[0101] In one embodiment, the fins include heaters that heat the exterior surfaces of the fins. One advantage is that it heats the web.

[0102] Mechanical Links In one embodiment, the mechanical link is a joint and has a degree of freedom to tilt the fin. The tilt can be induced under the action of unbalanced web tension. One advantage is that it compensates for the unbalanced tension of a flat web contacting the rollers at the onset of misalignment that occurs while the web is in contact with the roller system.

[0103] Preferably, the mechanical link 13 between the fin and the central roller 11 is located in the projection of a second axis DD' passing through the centre point or centre of gravity of the fin and perpendicular to AA'.

[0104] One advantage is that it compensates for the position of the web during the tendency of the web end to drift in one direction (left or right). A mechanical link allows tension to be rebalanced across the width of the web. The distance between the fin and the central roller in that direction is dynamically reduced to counteract the lateral displacement of the web. Preferably, a second axis DD' defines the boundary between the first and second sides of the outer surface 15 of the fin, the second side being preferably symmetrical of the first side with respect to the second axis DD'.

[0105] As shown in Figure 2, the mechanical link 13 between the fin and the central roller 11 allows the fin to tilt when the web goes off track and starts to drift. In other words, the angle Y between the second axis DD' and the longitudinal axis AA' is strictly less than 90°. In one embodiment, the angle Y between the second axis DD' and the longitudinal axis AA' is strictly less than 90° and is greater than 88°.

[0106] This range of angles advantageously allows for central location of the web on the fin.

[0107] For example, the roller system may include means for limiting the angle Y, such as stops positioned to limit the movement of the fins. The height and / or position of the stops may be configured to adjust the maximum inclination of the fins.

[0108] In a preferred embodiment, the mechanical link 13 is designed to allow the fin to tilt towards one end according to a rotation axis EE' that is perpendicular or sensibly perpendicular to the longitudinal axis AA' and the second axis DD' of the central roller 11. The mechanical link has one rotation axis and can exhibit different levels of rotational stiffness.

[0109] In a preferred embodiment, the mechanical link 13 does not allow rotation of the fin relative to the central roller about an axis parallel to the longitudinal axis AA' and / or the second axis DD'. In other words, the mechanical link 13 between the fin 12 and the central roller 11 is an axial rotational link including a single degree of freedom in rotation about the rotational axis EE' and zero degrees of freedom in translation.

[0110] In one embodiment, the mechanical link is designed to reach an optimum between its geometry and its chemical composition. The roller system can be designed to withstand high loads, high speeds, and vibrations. The design of the mechanical link can take into account the relationship between complex parameters such as the film thickness, its width, its elasticity, stiffness, bending or Young's modulus, its tension, the strain angle between the longitudinal axis AA' and the machine direction. The number of fins can also be related to the central roller diameter, the coefficient of friction of its outer surface, the web speed, the required alignment tolerances. For example, the shape and material can be defined by finite element analysis. The mechanical link can be welded, pressed in, bolted.

[0111] In one embodiment, the mechanical link is designed to reduce vibration during web transport. The stiffness of the mechanical link can be adjusted accordingly. One advantage is to dampen vibration when processing the web at high speeds. The damping means can include foam, rubber, or springs. One advantage is to adjust the tilt.

[0112] One embodiment of such a mechanical link is described with reference to non-limiting FIG.

[0113] In said embodiment, the roller assembly including the central roller 11, the central roller, the mechanical link and the fins 12 can be constructed from one inherent monoblock element. Preferably, the inherent monoblock element is constructed from a material based on polymeric materials such as polyamide, polystyrene or polyethylene. One advantage of a monoblock element is that it advantageously facilitates cleaning of the roller system 1, for example when immersed in a solvent or cleaning bath.

[0114] In said embodiment, the cross section of the mechanical link 13 between the central roller 11 and the fin 12 through a plane containing the longitudinal axis AA' and the axis of rotation EE' includes a central portion 133. The central portion 133 can be narrowed. One advantage is that it concentrates strains from unbalanced web tensions and allows tilting of the fin 12 relative to the central roller 11. The presence of this narrow portion can act as a more or less rigid axis of rotation depending on the characteristics of the material and its mechanical properties such as elasticity.

[0115] In another embodiment, each part of the roller system is made from a separate material. In another embodiment, each part may be removable. One advantage is to separate each element and clean each part independently, for example, using a solvent and / or a specific cleaning machine or process.

[0116] The exterior surface of the fins can vary depending on the type of web, allowing the film to drift easily over the web. The exterior surface of the fins may be coated, etched, mechanically or chemically treated. The exterior surface may be smooth, rough or corrugated, hollow, or flat. In one embodiment, the exterior surface may be coated with a silicone-based or fluorine-based layer. The exterior surface may be coated with polymers such as elastomers, rubber, tape, cloth, cork, acrylic, nitrile, butyl, EPDM, fluorocarbon, cotton, polyurethane, neoprene, SBR, silicone, etc. The exterior surface may be coated with anodized aluminum, ceramic, chrome, nickel, tungsten carbide. The exterior surface may include beads, roughness, holes, balls such as chrome balls, etc. Coatings or chemical treatments of the surface may provide additional features to the roller system. The exterior surface is slippery, solvent resistant, and easy to clean.

[0117] One advantage is that it reduces the surface tension of the outer surface, facilitating web slippage, and another advantage is that it avoids distortion of tension distribution and other web handling problems.

[0118] In one embodiment, the fins have different surface properties. One advantage is that each fin can be assigned a function for sliding or grip to ensure its coordination role.

[0119] In one embodiment, the dimension of the thin central portion 133 along the EE' axis is the same as the width of the fin 12 along the same EE' axis, advantageously blocking rotation of the fin 12 along other axes.

[0120] Preferably, the mechanical link further includes a first tapered portion 131 between the central roller 11 and the thin central portion 133 and / or a second tapered portion 132 between the fin 12 and the thin central portion 133.

[0121] These tapered sections advantageously reduce the risk of failure of the mechanical links and increase the life of the roller system.

[0122] In an alternative embodiment, the mechanical link 13 includes a hinge means between the fin and the central roller to provide a one degree of freedom connection in rotation such that it provides a rotational joint.

[0123] In one alternative or cumulative embodiment, the fins are mechanically fixed to the central roller 11 and the fins 12 have elasticity that allows both sides of the fin to bend under the action of tension on the flat web from a relaxed position to an engaged position.

[0124] In a preferred embodiment, each fin 12 is movable relative to the central roller 11 about an axis of rotation EE' independently of the others.

[0125] In one embodiment, the mechanical link may include several parts or may include several mechanical links. The pivot function provided by the mechanical link may be decomposed into several pivot functions. The mechanical link may comprise one pivot joint with the central roller and one pivot joint with the fin, each joint being connected by a connecting means such as a rod. The two pivot joints may exhibit different stiffness. One advantage is to combine the tilt and damping of the fin.

[0126] In one embodiment, the joints can include compliant mechanisms. One advantage is to adjust the position of the fin or each fin of a set of fins when the total torque about the pivot point exerted by the webs on the outer surface is higher on the first portion than on the second portion, respectively, or higher on the second portion than on the first portion. Another advantage is to be able to smoothly, gradually, and abruptly switch the fins from one position to another.

[0127] In one embodiment, the fin or each fin of the set of fins is configured to tilt or rotate continuously from a first position, over a second position, to a third position in response to the distribution of pressure exerted by the web on the outer surface, such that when the torque exerted on the length of the lever arm relative to the tilt axis is higher on the first portion than on the second portion, the fin will tilt, thus decreasing the pressure and torque on the first side and increasing the pressure and torque on the second side, until the torque on either side is balanced.

[0128] Lateral compensation for flat webs Next, an implementation of the invention to avoid and / or correct lateral deviation of a flat web will be described. The fins 12 in contact with the circulating web 2 move from a relaxed position to an engaged position to correct the lateral deviation. When the fins are no longer in contact with the web, they resume their relaxed position. During rotation, the roller system continuously has at least one fin in contact with the web, and at least one fin tends to tilt. One advantage is that it creates a dynamic and compliant roller.

[0129] Relaxed (or idle) position In the "relaxed position", a gap exists between each fin. This gap prevents each fin from coming into direct contact with the adjacent fin. In the relaxed position, the spatial gap between two adjacent fins is managed. In the relaxed position, each gap dimension is sensorily stable and homogeneous to avoid the fins overlapping or touching. Thus, the roller system can be circumscribed within a rectangular cylinder. This spatial gap advantageously allows the activation of the "engaged position" upon tension imbalance across the web.

[0130] FIG. 1 shows a fin of a roller system according to an embodiment of the invention in a relaxed position.

[0131] In this relaxed position, the flat web 2 can be centered sensibly on the second axis DD'. As the web runs over the rollers, its center of width is aligned with the machine direction that intersects the second axis DD' defined by the mechanical link 13.

[0132] In one embodiment, each fin is symmetrical about an axis perpendicular to the longitudinal axis AA'.

[0133] In the relaxed position, the contour of the outer surface 15 is symmetrical about a plane perpendicular to the longitudinal axis AA'. The "contour" of the outer surface 15 may be understood as the contour according to a plane passing through the AA' axis and the fins.

[0134] According to one embodiment, in the relaxed position, a first distance B between the outer surface of the first side and the longitudinal axis AA' is equal or approximately equal to a second distance C between the outer surface of the second side and the longitudinal axis AA', the first distance and the second distance being measured at points equidistant from an orthogonal plane of symmetry.

[0135] Engagement position The engaged position (or "tilted position") may result from tension differentials across the film on one side in contact with the fin 12. Such imbalances may lead to instabilities during web transport. Tension asymmetries may intensify the web roller misalignment angle between the web edge and the machine direction, initiating or accentuating lateral shifts of the web. In other words, the engaged position may be triggered by the initiation of lateral shifts of the web and / or when unequal tension occurs across the width of the web, especially at its edges.

[0136] To address this phenomenon, the fins may tilt / bend relative to the mechanical link. The fins 12 in contact with the web may tilt to the lateral side where the tension in the web is higher. The fins in contact with the web may be in an engaged position and tilt and / or bend. The tension difference present at one side edge of the flat web in contact with the outer surface of the fin induces the tilt of the fin. When the engaged position is triggered, the fins in contact with the web may bend to one side.

[0137] A mechanical link allows the fins to rotate about the axis EE' to reach the engaged position (or "tilted position"), a second axis DD' which presents an angle Y with the longitudinal axis AA', strictly less than 90° or equal to 89.5° or 89°. Once in the engaged position, the gap between each fin can vary along the length of the fin. The sides on which the fins can be tilted are reshaped as a result. Thus, a lateral shift of the flat web on the roller assembly results in the tilting of the fin 12, which re-centers the flat web on the outer surface.

[0138] In the engaged position shown in FIG. 2A, a first distance B between a first side of the roller system 1 and the longitudinal axis AA' is greater than a second distance C between a second side of the roller system and the longitudinal axis AA'.

[0139] The distance C between the side of the fin and the longitudinal axis AA' is shorter in the engaged position than in the relaxed position. This change in distance advantageously allows the correction of misalignments of the flat web transported by the roller system. Indeed, the greater the distance between the flat web and the longitudinal axis, the greater the radial speed. The radial speed difference along the width of the flat web allows the flat web to climb the incline and the flat web to return to its center.

[0140] The second side is the side where the fin is angled, i.e. the side where the higher web tension is offset.

[0141] Here, the first distance B and the second distance C are the distances between a point on the outer surface 15 of the fin 12 and the longitudinal axis AA' of the central roller. In the engaged position, the first distance B is greater than the second distance C, so that the course of the web contacting the roller system is different. In other words, the path taken by the web is modified to compensate for the unbalanced tension. For the web, the tilt of the fin shortens the path on the side with higher tension and lengthens the path on the opposite side. The dynamic adjustment of the path of the web on the roller system allows the tension of the web to be rebalanced over its entire width. In the engaged position, the roller system acts as if one end is expanded compared to the other end.

[0142] The fin is in continuous contact with the web while the roller system rotates about its central roller axis AA'. When in contact with the web, the fin is operable in an engaged position and is capable of immediately regaining its relaxed position upon ceasing contact with the web.

[0143] The symmetry of the profile of the outer surface of the fin 12 advantageously allows the position of the flat web in the center of the fin 12 to be stable in the relaxed position.

[0144] A second engagement position, in which the fins are angled in the other direction, is shown in Figure 2B. In this second engagement position, the first distance B is less than the second distance C.

[0145] Transport System A roller system can be inserted into the conveying system 200 to hold and / or convey the flat web 2. The presence of such a roller system advantageously avoids and / or eventually corrects lateral shifts of the flat web autonomously. The conveying system 200 can be implemented in a machine. The machine can be a printer, a coating line, a film extrusion line, etc.

[0146] One embodiment of a transport system 200 according to an aspect of the present invention will now be described with reference to FIG.

[0147] The transport system 200 may include at least one roller 202, 203 that holds and transports the flat web. The transport system 200 may include multiple rollers 202, 203. The multiple rollers may be mounted on a frame, if desired, and rotate on their own to transport the flat web 2 along its periphery. The rollers may have the shape of a cylinder or be circumscribed within a cylinder. Additionally, conical, concave, convex, diablo or tapered rollers may be used in any configuration. The rollers may be mounted on a frame to rotate about their longitudinal axes.

[0148] At least one roller of the plurality of rollers is a roller system 1 according to the present invention.

[0149] Although the invention is intended primarily for use in converting processes, it can also be used in any situation where a web rotates around a roll. One example is the distribution belt in an automobile engine.

[0150] Roller systems can be inserted into conveying systems including cores, core center rollers, line center rollers, mandrels, drive belts, pulleys, spools, take-up rolls. Roller systems can be used in conjunction with or in place of spreaders, bowed rollers, crowned rollers, conveying rollers, web drives (idlers), accumulators, dancer rollers, end guides, guide rollers, load cell tension rollers, spreader rollers (curved, concave, dual, end pull), squaring rollers, skew-in rollers, winders, winder lay-on rollers.

[0151] One advantage of roller systems is that they can be easily inserted into existing systems, without the need to change the entire machine or rebuild the machine. Furthermore, no cables or additional electronic or hydraulic means need to be added. Furthermore, the insertion of the roller system is independent of the cause of the misalignment and does not require a full understanding of which roller is the cause of the misalignment. Thus, troubleshooting and costs related to misalignment are eliminated. The frequency of regular misalignment and / or roller replacement can be reduced (maintenance). Misalignment and misalignment tolerance adjustment can be made easier. Web sagging and / or deflection due to gravity can also be reduced.

[0152] The presence of a roller system can correct in-plane misalignments and accurately realign the web without tools (manual or optical transit). The roller system can also address relaxation of the plastic web or absorb creep of the plastic film.

[0153] At least one of the rollers 202 is preferably a drive roller that includes a motor that controls the rotation of said drive roller to transport the web 2 .

[0154] The roller system can address machine vibrations due to roller imbalance. In fact, misalignment can cause or be caused by vibrations. Thus, proper web alignment advantageously reduces web stress variations, reduces wrinkling, improves the life of machine parts, and reduces premature failure of machine parts.

[0155] In one embodiment, the transport systems upstream and downstream of the system according to the invention include means for controlling the mechanical tension of the web. In one example, such means include a spring-loaded tension roller. The controller can adjust the movement of the tension roller 220 in response to inputs detected by the bandpass sensor. Additionally, the web can be kept at a constant tension, such as by looping a band around a spring-loaded tension roller mounted on a linear slide upstream and downstream of the system according to the invention.

[0156] example A proof of concept was performed using an endless band that moves cyclically around a driven roller (also called a "speed roller") and an idler roller equipped with a spring to manage the tension in the web. The idler has an adjustable rotation axis to change its direction during the experiment in order to artificially generate a web-roller misalignment angle between the web and the roller. The experimental setup is further equipped with a profile sensor to detect and measure the position of the edge of the web.

[0157] In reality, the lateral deviation is aggravated during the rotation of the endless band around the loop. The magnitude of the lateral deviation can accumulate after each cycle. In the absence of a corrective measure, the band accumulates lateral deviation and the deviation becomes more and more pronounced.

[0158] The experiments simulate lateral misalignment, which can occur due to imperfect alignment of the roller axes in a transport system. To mitigate this lateral misalignment, a compliant roller with eight fins is used to demonstrate web position correction. The current design of the compliant roller is manufactured with an additive manufacturing process where the materials are not isotropic (layer-by-layer). The orientation of the layers is chosen such that the layers are parallel to a central plane perpendicular to axis AA' to achieve rotational symmetry.

[0159] The results of this experiment are shown in Figure 8, which shows the edge position S (mm) (or lateral position) at time T (sec).

[0160] At the beginning of the experiment (T = 0 s), the web is in the center of the roller system.

[0161] Next, the web is manually shifted laterally (T=0s and 50s).

[0162] If the idler is replaced with an eight-fin polyamide roller, a compliant joint or mechanical link allows the fins to tilt or bend under load. After 500 seconds, the band returns to its initial position.

[0163] In another example, a finned roller is used to avoid or remove wrinkles. The central portion of the fin is fixed at its center in a plane perpendicular to AA'. The fixation may be permanent and rigid.

[0164] In the rest state, the roller is preferably surrounded by a right cylinder. In use, the tip of the fin can move upwards or downwards. It creates a curved shape at the tip of the roller. The shape can be adjusted to induce either a convex or concave shape from the tip of the roller. The tip of the first part and the tip of the second part can move independently, relative to each other. This configuration allows for greater flexibility and freedom, from a geometric point of view, to adjust the curvature according to specific needs that arise during web processing. For example, the left fin can be bent in one direction without the right fin being bent in the same direction. Or, the two sides can be bent in the same direction, or one side can be bent without any bending from the other side.

[0165] Advantageously, this allows to obtain different forms of the cylinder. The cylinder can have a cylindrical shape, one convex or one concave. It can also have one side with a certain shape and the other side with another shape. For example, the left side can be convex and the right side can remain cylindrical. All combinations are conceivable in this embodiment.

[0166] Advantageously, this embodiment allows for more efficient and easier removal of web wrinkles by targeting the responsible side without affecting the other side.

[0167] support In another embodiment, shown in Figure 10, the support is a fixed support that includes a single fin. In this embodiment, the support is mechanically connected to the frame 100 of the transport system 200. The fins described previously are mechanically connected to the surface of the support with mechanical links similar to the mechanical links described previously.

[0168] In this embodiment, the web slides over the outer surface of the fin during transport by the transport system, and the mechanical connection between the fin and the support allows the fin to tilt when a lateral shift of the web occurs, causing the web to be off-centered as previously described.

[0169] In this embodiment, the outer surface of the fin advantageously comprises a coating that allows modifying the friction between the outer surface of the fin and the web to adjust the sliding.

[0170] The support element is preferably a cylinder or part of a cylinder extending along a longitudinal axis AA'. Preferably, the cylinder comprises a non-circular hollow cylinder, such as a parallelepiped or a rectangular prism.

Claims

1. A roller system (1) for transporting a web (2), comprising: a central roller (11) rotating about a longitudinal axis (AA'); a set of fins (12) arranged about said longitudinal axis (AA'), each fin having two opposing lateral portions; Equipped with each lateral portion of each fin is movable such that a first distance between one lateral portion and the longitudinal axis (AA') is smaller or larger than a second distance between an opposing lateral portion and the longitudinal axis (AA'); Roller system (1).

2. A roller system (1) according to claim 1, each fin of the set of fins having an outer surface for supporting the web; the exterior surface defines a first lateral portion of the fin and a second lateral portion of the fin; the second lateral portion is separated from the first lateral portion by a plane perpendicular to the longitudinal axis (AA'); Roller system (1).

3. A roller system (1) according to claim 2, Each fin is a first position, where a first distance between the first transverse portion and the longitudinal axis (AA') is smaller than a second distance between the second transverse portion and the longitudinal axis (AA'); a second position where the second distance is less than the first distance; and is movable relative to the longitudinal axis (AA') between at least two positions: Roller system (1).

4. A roller system (1) according to claim 3, the fin is configured to move from the first position to the second position under a higher effect of a total force exerted by the web on the second lateral portion. Roller system (1).

5. A roller system (1) according to claim 3, the first lateral portion and / or the second lateral portion of each fin are designed to flex between the first position and the second position; Roller system (1).

6. A roller system (1) according to claim 4, Each fin is mechanically connected to the central roller (11) by a mechanical link (13); Each fin (12) is configured to tilt about a mechanical link (13) to move from the first position to the second position or to a third position. Roller system (1).

7. A roller system (1) according to claim 6, the mechanical link comprises an axial pivot connection between the fin (12) and the central roller (11); Roller system (1).

8. A roller system (1) according to claim 7, the mechanical link (13) between the fin (12) and the central roller (11) comprises a joint having at least one tapered portion (131, 132); Roller system (1).

9. A roller system (1) according to claim 8, The joint between the central roller (11) and the fin (12) is a thin central portion (133); a first tapered section (132) that decreases in thickness from the fin (12) to the thin central section (133); a second tapered section (131) whose thickness decreases from the central roller (11) to the thin central section (133); Equipped with Roller system (1).

10. A roller system (1) according to any one of claims 8 to 9, In the first or second position, a second axis (DD') perpendicular to the outer surface passes through the mechanical connection (13) and is inclined to the longitudinal axis (AA') by an angle (Y) strictly less than 90°. Roller system (1).

11. A roller system (1) according to any one of claims 3 to 9, Each fin is movable relative to the longitudinal axis (AA') between at least the first position, the second position, and a third position; the profile of the outer surface is symmetrical with respect to the plane; Roller system (1).

12. A roller system (1) according to any one of claims 2 to 9, The profile of the outer surface of the fin (12) includes a concave profile. Roller system (1).

13. A roller system (1) according to any one of claims 2 to 9, The profile of the outer surface of the fin (12) includes a convex profile. Roller system (1).

14. A system (1) for conveying a web (2), comprising: a support element having a first surface; at least one fin disposed on the first surface, the fin having two opposing lateral portions; Equipped with each lateral portion of the fin is movable such that a first distance between the lateral portion and the first surface is less than or greater than a second distance between the opposing lateral portion and the first surface; System(1).

15. A system (1) according to claim 14, The at least one fin is a first position in which the profile of the outer surface is symmetrical about the first plane; a second position in which a first distance between a first lateral portion and the first surface is less than a second distance between a second lateral portion and the first surface; a third position where the second distance is less than the first distance; It can be moved between three positions: System(1).

16. A system (1) according to claim 15, the fins are configured to move from the first position to the second position or the third position under an effect of a total force exerted by the web being higher on the first lateral portion or the second lateral portion, respectively; System(1).

17. A conveying system (200) including a plurality of rollers (1, 202, 203), - conveying the web along a predetermined path and at least one roller system according to any one of claims 1 to 9 and / or a system according to any one of claims 14 to 16, A transport system (200).

18. 1. A method for conveying a web, comprising: A transport system according to claim 17, A roller system according to any one of claims 1 to 9 and / or said system, a web moving mechanism for moving the web along a predetermined path and for automatically correcting web misalignment; method.

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