The present invention relates to a guide system for handling webs of paper material. In particular, a system for handling webs of paper material in accordance with the present invention can be used for guiding such webs inside so-called “paper converting” line in which the webs, unwound from parent reels that feed them, undergo a series of transformations which determine the production of articles of paper material, such as rolls of toilet paper or rolls of kitchen paper and more general so-called “sanitary” items including handkerchiefs and paper napkins.
It is known that, in general, a paper converting plant comprises a series of machines and equipment arranged according to an operating path followed by one or more webs of paper material which, along this path, are subjected to operations such as embossing, printing of logos or ornamental designs, rolling or folding and finally the packaging of finished products.
U.S. Pat. No. 5,255,602 describes a system for drawing in webs used by printing machines in which a strip of “Velcro” is applied on the entire front edge of the web transversely to a drawing in direction.
Some operations, such as drawing in and the initial preparation of the webs unwound from the mother reels that feed them, are carried out in an almost completely manual way, which implies the need of highly specialized personnel and involves risks for the safety of the operators themselves. For example, in the phase of preparation of the webs for drawing in or in case of breaking of the webs in use, a free front edge of a web wound on a mother reel is manually torn, so as to obtain a portion of a roughly triangular shape intended to be knotted to a drawing-in belt which then leads the web along the aforementioned path to allow its use by the equipment and machines that make up the paper plant converting. However, depending on the weight of the paper and the experience of the operator, this operation can be difficult and can produce different results from time to time, with the risk of producing unwanted breaks in the paper and the consequent need to repeat the operation. Furthermore, in these phases the operator is obliged to stay for a long time in areas intrinsically risky for his safety. The main object of the present invention is to eliminate, or at least strongly reduce, the aforementioned drawbacks.
This result has been achieved, in accordance with the present invention, by adopting the idea of providing a guide system for handling webs of paper material having the characteristics indicated in claim 1. Other characteristics of the present invention are the subject of the dependent claims.
Thanks to the present invention, it is possible to simplify the preparation operations of the paper material webs used in paper plants converting, reducing the degree of experience required for the operators and, at the same time, ensuring their correct execution regardless of the paper weight. Furthermore, the preparation operations of the paper material webs can be carried out in an automatic mode, which ensures constant compliance with a predetermined preparation standard and allows operators to supervise these operations from the outside, i.e. outside the areas occupied by the system. In addition, a guide system according to the present invention has a relatively simple mechanical structure.
These and further advantages and characteristics of the present invention will be better understood by every person skilled in the art thanks to the following description and the attached drawings, provided by way of example but not to be considered in a limiting sense, in which:
FIG.1 represents a schematic side view of a guide system according to the present invention at an initial stage of preparing a web of paper material;
FIG. 2 is a schematic front view of the system represented in FIG. 1;
FIG. 3 is a schematic side view of the system of FIG. 1 in a subsequent operating step;
FIG. 4 is a schematic front view of the system represented in FIG. 3;
FIG. 5 is a schematic front view of the system shown in FIG. 1 in an operating step subsequent to that shown in FIG. 3;
FIG. 6 is a schematic front view of the system represented in FIG. 5;
FIG. 7 represents a detail of FIG. 1;
FIG. 8 represents another detail of FIG. 1;
FIG. 9A shows a detail of FIG. 1 illustrating a possible embodiment of the gripping means (1) while the cutting means are in the operative position;
FIG. 9B represents a detail of FIG. 9A in which some parts are omitted to better highlight others;
FIGS. 10A-10C are cross-sectional views of possible embodiments of a hooking belt (40);
FIGS. 11A-11C are schematic side views of release mechanisms of the web from the hooking belt;
FIGS. 11D-11F are partial front views of the release mechanisms of FIGS. 11A-11C;
FIG. 11G is a schematic side view of a further embodiment of a mechanism for releasing the web from the hooking belt;
FIGS. 12A-12E show different views of the frame (41);
FIGS. 13A-13C show three perspective views of the cutting means of the system represented in the previous figures;
FIG. 13D is a schematic longitudinal sectional view of the cutting means illustrated in FIGS. 13A-13C;
FIG. 14 is a simplified block diagram relating to a possible automatic control mechanism for controlling the operating units of the system represented in the previous figures;
FIG. 15 is a schematic plan view of a possible front cutting profile of a web of paper material;
FIG. 16 is similar to FIG. 4 but it refers to the case in which a front cutting profile of a web is made as schematically shown in FIG.15.
Reduced to its essential structure and with reference to FIGS. 1-14 of the annexed drawings, a guide system for handling webs of paper material in accordance with the present invention comprises:
- gripping means (1) configured to engage a web (W) of paper material wound on a parent reel (PR) and to control its movement along a predetermined advancement direction (WF);
a structure (2) on which said gripping means (1) are supported at a predetermined distance (d) by a support (3) configured to support the parent reel (PR) in a predetermined position (A) where the same reel (PR) can rotate around its own longitudinal axis;
- hooking means (4) adapted to temporarily hook a lateral edge (SW) of the web (W), arranged downstream of the gripping means (1) with respect to the aforesaid advancement direction (WF);
- cutting means (5) adapted to cut the web (W) arranged upstream of said hooking means (4) with respect to the aforesaid advancement direction (WF).
Preferably, the cutting means (5) are arranged in proximity to the gripping means (1). With reference to the embodiment example shown in FIGS. 1-14, the gripping means (1) comprise two parallel rollers (10, 11) oriented orthogonally to the advancement direction (WF), which are configured and controlled for forming a pressure nip that can be crossed by the web (W). A first roller (10) is in a fixed position and is motorized, while a second roller (11) is mounted, idle, on a support arm (12) which can be moved to and from the first roller (10) by means of an actuator (13) that controls their rotation around an axis (H) parallel to the axis of the same rollers (10, 11). Therefore, when the second roller (11) is approached to the first roller (10), by means of the rotation of the arm (12) controlled by the actuator (13), said pressure nip is formed and the web (W) is dragged by the rollers (10, 11) in the advancement direction (WF). Conversely, by moving the second roller (11) away from the first roller (10), the pressure nip is removed and the rollers (10, 11) no longer exert the dragging action on the web (W). Preferably, the second roller (11) is a roller provided with a rubber coating. For simplification, in the drawings the means (100) which control the rotation of the roller (10) around the respective axis are shown only in FIG. 14.
With reference to the embodiment example shown in the attached drawings, the structure (2) that supports the gripping means (1) comprises a metal frame with two uprights (20) on which the gripping means (1) are connected at a predetermined distance (h) from the base (B) of the system. In this example, the aforementioned rollers (10, 11) are arranged orthogonally between the uprights (20) of the structure (2) and the arm (12) of the second roller (11) is hinged with a horizontal axis on the upper side of the uprights (20). Furthermore, a connecting crosspiece (21) is arranged between the uprights (20) in such a way that, as a whole, the structure (2) substantially has a portal shape.
With reference to the embodiment example shown in FIGS. 1-14, the support (3) for the parent reel (PR) is a support, per se known, comprising two sides (30) between which more belts (31) are arranged closed in a ring on corresponding guide and dragging rollers (32). In practice, the support (3) is a cradle in which the parent reel (PR) is positioned and in which the belts (31), suitably motorized, determine the rotation of the parent reel (PR) which is constrained to two coaxial pins (33) arranged on its longitudinal axis in the aforementioned position (A). When the belts (31) are activated, the parent reel (PR) rotates around the pins (33) due to its contact with the belts themselves. As previously mentioned, such a support is known per se to those skilled in the art, as the actuation and control of the belts (31).
With reference to the embodiment shown in the attached drawings, the lateral hooking means for the web (W) comprise a hooking belt (40) mounted on a frame (41) which can be moved between an inoperative position spaced from the lateral edge (SW) of the web (W) and an operative position close to said edge. The lateral edge (SW) of the belt (W) is a longitudinal edge of the latter.
In FIG. 1, FIG. 2, FIG. 5 and FIG. 6 the frame (41) is in the inoperative position, while in FIG. 3 and FIG. 4 it is in the operative position for hooking the lateral edge (SW) of the web (W). For example, the frame (41) is formed by a plate hinged, on its lower side (410), around a horizontal axis (H4) oriented orthogonally to the uprights of the structure (2). Said axis (H4) is made by connecting the lower side (410) of the frame (41) to a support base formed by two plates (B4) aligned along a direction orthogonal to an upright (20) of the structure (2) by means of a corresponding hinge (C4). In the accompanying exemplary drawings, the frame (41) is hinged on the left upright (20) of the structure (2). The double arrow “R4” in FIG. 12E represents the rotation of the frame (41) around the axis (H4). The rotation of the frame (41) around the axis (H4) is controlled by an actuator (A4) placed on one side of the frame (41). The hooking belt (40) is a belt actuated by a respective electric actuator (42) integral with the frame (41). In the accompanying exemplary drawings, the actuator (42) controlling the belt (40) is integral with the lower part (410) of the frame (41). Since the actuator (42) is integral with the frame (41), the belt (40) is controlled by the actuator (42) even when the frame (41) rotates around the axis (H4). Said hooking belt (40) develops along a closed circuit (P4) having a first descending branch (PH), along which the belt hooks the lateral edge (SW) of the web (W), and a second branch (PT) along which the web (W), hooked to the belt (40), is guided towards an exit area (PE). With reference to the enclosed exemplary drawings, the first branch (PH) of the circuit (P4) is oriented like the mobile frame (41), while the second branch (PT) passes under the support (3) of the parent reel (PR). The hooking belt (40) is guided on a plurality of pulleys (40P) arranged on an internal side (41N) of the frame (41). Therefore, along the branch (PH) of the circuit (P4), the belt (40) is subjected to the same movements imposed to the frame (41). Consequently, when the frame (41) is approached to the lateral edge (SW) of the web
(W) also the branch (PH) of the circuit followed by the belt (40) approaches the lateral edge of the web and, vice versa, when the frame (41) is moved away from the lateral edge (SW) of the web (W) also said branch (PH) moves away from the lateral edge of the web.
The first branch (PH) of the circuit (P4) constitutes an engagement branch of the lateral edge (SW) of the web (W).
The second branch (PT) of the circuit (P4) is an extension of the first branch (PH) which leads the lateral edge (SW) of the web (W) towards a downstream release point (PE) distanced from the system area in which the hooking means are arranged.
In the examples shown in the drawings, the second branch (PT) is substantially horizontal but it is understood that the orientation of this branch (PT) can be different, depending on the arrangement of the machines or devices that use the web. The hooking belt (40) has an internal side (40N) facing the support (3) of the parent reel (PR), i.e. facing the direction from which the web (W) comes, and an opposite external side (40E).
The arrows in FIG. 8 show the movement of the belt (40) along the path (P4). The nails (46), i.e. the projections, of the belt (40) can be distributed uniformly over the entire length of the belt itself, or can be arranged on selected sections of the latter. To facilitate the hooking of the web (W) by the belt (40), a movable presser (42) is advantageously provided which pushes the edge (SW) of the web (W) on the inner side of the hooking belt (40) when it is it is necessary to carry out the web hooking phase. For example, the mobile presser (42) consists of a brush rotating around a horizontal axis (K) orthogonal to the frame (41) and mounted on a respective support arm (43) which, in turn, is hinged on the frame (41) with axis (J) parallel to that of the brush and enslaved to a pneumatic actuator (44) which determines the movement of the brush to and from the hooking belt (40). Alternatively, said presser is constituted by a rubber wheel (not shown in the drawings), arranged like the aforementioned brush. In a possible embodiment, the hooking belt (40) is provided with projections suitable for piercing the web (W) in said hooking step. For example, the belt (40) is a belt with a rectangular cross section, as in FIG. 10A, on which nails (46) are inserted at a predetermined distance from each other, the tip of which protrudes beyond the inner side (40N) of the belt. Alternatively, the belt (40) is a belt with longitudinal grooves in the center of which the nails (46) are positioned as shown in FIG. 10B. Again, alternatively, the belt (40) can have a trapezoidal cross-section with the major base forming the inner side (40N) of the belt, as shown in FIG. 10C, provided with nails similarly to the other examples described. In practice, the hooking belt (40) is a flexible element equipped with hooking projections or points (46) capable of hooking to the web (W) when the phase of hooking the lateral edge (SW) of the web is activated. The nails (46), or projections, of the belt (40) can be distributed uniformly over the entire length of the belt itself, or can be arranged on selected sections of the latter. Preferably, a guide system according to the present invention also comprises a mechanism for releasing the web (W) from the hooking means (4). For example, when the hooking means comprise the previously described belt (40) provided with nails, the release mechanism can be of the type shown in FIG. 11A, FIG. 11B or FIG. 11C. The release mechanism shown in FIG.11A comprises two curved rods (45), parallel to each other and spaced apart by a sufficient amount to allow the transit of the nails (46) in the space resulting between the rods (45). The latter form a bridge between the output side (PE) of the aforementioned path (P4) and a second belt (400), which is structured like the belt (40) being also provided with points or protrusions suitable for penetrating the web (W) to engage it at the same side (SW) engaged by the first belt (40). To facilitate the transfer of the belt (W) on the second hooking belt (400), a pulley (401) with a central groove (402) can be positioned on the end of the rods (45), i.e. above the inlet side of the second hooking belt (400). In practice, the edge of the web hooked to the nails (46) of the first hooking belt (40) is on the rods (45), while the nails (46) pass through the space between the rods (45), and, while traveling towards the machines that use it, the edge of the web (W) which is now unhooked from the belt (40) is hooked by the nails of the second belt (400). The pulley (401) makes it easier to hook the side edge of the web (W) to the second belt (400). FIG. 11A shows a pulley (40E) for guiding the belt (40) in correspondence with the aforesaid output side (PE) and a pulley (405) for guiding the belt (400) at the respective inlet side.
The release mechanism shown in FIG. 11B comprises a brush (47) located on the output side (PE) of the circuit (P4) and aligned with the belt (40) provided with nails. The brush (47) rotates in the direction indicated by the arrow in FIG. 11B depicted on the same brush, so it acts in such a way as to remove the lateral edge of the web from the nails of the belt (40) directing it towards the belt (400) located downstream which has the same configuration previously described with reference to the example of FIG. 11A. Also in this example the pulley (401) of the previous example can be used, arranged so as to form a bridge between the brush (47) and the pulley (405) that guide the belt (400).
The release mechanism shown in FIG. 11C comprises a set of nozzles (RN) arranged on the outlet side (PE) of the circuit (P4) so as to blow air upwards and, on the opposite side, the pulley (401) previously described which rotates in a direction concordant with the direction followed by web belt (W) forming a bridge between the belt (40) and the belt (400) previously described
The release mechanism illustrated in FIG. 11G comprises a brush (406) arranged above the outlet side (PE) of the aforementioned path (P4). The belts (40) and (400) are on two paths side by side and share the pulley (407) positioned on said output side (PE). The belt (400) downstream of the belt (40) has the same configuration described previously with reference to the example of FIG. 11A. The brush (407), similarly to the pulley (402) of the examples shown in FIG. 11B and FIG. 11C, pushes the paper web on the tips of the belt (400) which thus takes it over.
In all the examples described above, the second belt (400) guides the web (W) towards a final release point downstream.
With reference to the embodiment example shown in the attached drawings, the cutting means (5) are arranged above the gripping means (1) and comprise a blade (50) mounted on a mobile support (51), for example a carriage, controlled by an electric motor (52) by means of a belt (53) to which the mobile support (51) is connected. The mobile support (51) moves on a guide (2G) formed on the crosspiece (21) connecting the uprights (20) of the structure (2). On the same crosspiece (21) pulleys (5Z) are mounted on which the belt (53) is guided. The blade (50) is mounted on a lever (5L) controlled by a respective pneumatic actuator (55), arranged on the mobile support (51), allowing the blade to be moved to and from the gripping means (1). With reference to the examples shown in the attached drawings, a corresponding end of the lever (5L) is hinged on the free end of the actuator (55). On the other end of the lever (5L) the blade (50) is hinged, free to rotate around its own axis, by means of a respective hinge (5K). The axis of rotation of the blade (50) and the axis of the hinge (5P) that connects the lever (5L) with the actuator (55) are parallel to each other and are orthogonal to the stem of the actuator (51). The actuator (55) is fixed on one side of an arm (54) on whose front part (540) the lever (5L) is pivoted by means of a hinge (5H) with axis parallel to the axis of rotation of the blade (50). The hinge (5H) is at an intermediate position between the hinge (5P) and the hinge (5K). On its front side (540), the arm (54) has a lower cylindrical appendix (5M) which is oriented towards the rear side of the same arm (54) and is inserted in a tubular bushing (5N). The latter is a front appendage of the mobile support (51). Therefore, the blade can be translated along the guide (2G) by means of the mobile support (51) and furthermore it can be moved to and from the fixed roller (10) by means of the actuator (51). In practice, the group formed by the actuator (55), the arm (54), the lever (5L) and the blade (50) can translate along the guide (2G) being constrained to the mobile support (51) controlled by the motor (52). Furthermore, the same assembly can rotate freely around the axis of the bushing (5N).
By suitably combining the translation speed of the carriage (51) and the rotation speed of the fixed roller (10), it is possible to transversely cut the web (W) according to a profile having a predefined shape. For example, by setting a constant rotation speed for the fixed roller (10) and a constant translation speed for the carriage (51), the web will be cut forming a triangular flap (TW), as schematically represented in FIG. 4 and as further described below, on the side of the web (W) intended to be hooked by the hooking means (4). A further method of controlling the cutting means is described below.
A possible operating cycle of the guide system described above, with reference to the application example illustrated in FIGS. 1-6, is the following.
As shown in FIG. 1, in a first phase, an operator inserts through the gripping means (1) a free front edge of the web wound on the parent reel (PR) arranged on the support (3) and the belts (31) are activated to make the parent reel to rotate at a predetermined speed allowing the web (W) to unwind. This unwinding phase is started by the operator himself, through a control panel (not visible in the drawings). In this phase, the gripping means (1) are activated, i.e. the roller (11) is brought closer to the roller (10) so that the web (W) is in the nip thus formed by the same rollers (10, 11) which control its advancement along the direction (WF). Optical sensors (101), shown only in the diagram of FIG. 14, arranged and acting on one side of the system opposite to the side where the hooking means (4) are installed, detect that the web (W) has passed the gripping means (1) and is completely spread over its entire width (WW), as shown in FIG. 2. In this phase, the free front edge (FE) of the web (W) is collected on a tray (V) arranged under the gripping means (1). The blade (50) is in an inoperative position, spaced from the roller (10) and arranged on the side of the guide (2G) closest to the hooking means (4), i.e. on the left of the structure (2) with reference to the exemplary drawings, as shown in FIG. 2.
Subsequently, the cutting means (5) are activated, moving the blade (50) towards the roller (10), and activating the motor (52) which determines the translation of the carriage (51) towards the opposite side of the structure (2) , that is to the right with reference to FIG.4 in which the arrow “F5” represents the translation of the carriage (51) in this phase of the process. In this way, the blade (5) also translates like the carriage (51). Therefore, the web (W) is cut, producing a flap with a substantially triangular part (TW) in correspondence with the side of the web (W) intended to be hooked by the hooking means (4) and a flap (DW) which, at the at the end of the cutting phase thus performed, will be detached from the parent reel (PR), collected on the tray (V) and recycled. At the same time, the means (4) for hooking the web (W) are activated, with the rotation of the frame (41) around the axis (4H) which determines the overlap of the path (PW) followed by the lateral edge (SW) of the web (W) to the branch (PH) of the circuit (P4), and the brush (42) is pushed towards the web (W). In this way, the lateral edge (SW) of the web (W) will be hooked to the belt (40). With reference to FIG. 4, the lateral edge (SW) hooked by the belt (40) is the left edge of the flap (TW). Since the belt (40) is driven, said edge (SW) is guided along the path followed by the same belt (40) to the exit point (PE) of the path (P4). Then, after a predetermined time has elapsed from the activation of the hooking means (4), sufficient to ensure that a predetermined length of the lateral edge (SW) of the web (W) is hooked to the belt (40), the brush (42) and the frame (41) are returned to their initial inoperative positions, as illustrated in FIG. 5 and FIG. 6. Similarly, the roller (11) and the cutting means (5) are returned to their respective initial inoperative positions. As a result, the lateral edge (SW) of the web unwinding from the parent reel will no longer be hooked to the belt (40) and will move along a path parallel to the section (PT) of the same belt. At this point, the web can be unwound from the parent reel with a higher unwinding speed determined by the downstream machines that use it and by the speed of the belts (31) that control the rotation of the parent reel (PR). In FIG. 6 the cutting means (5) have reached the end-of-stroke position (on the right in the figure) and the front edge (AW) of the web (W) is correctly cut straight.
The perforations induced on the lateral edge (SW) of the web (W) by the hooking belt (40) do not produce significant reductions in the quality of the finished product, considering that in general the lateral edges of the web are eliminated and discarded before making the finished products: for example, if the web (W) is used to produce logs from which rolls of toilet paper are obtained, the logs are subjected to a trimming operation consisting in cutting the end portions. And in any case, generally the first logs produced are discarded.
The system described above therefore makes it possible to guide a paper web along a predefined path by engaging one side thereof in an initial phase of the guiding process, automatically and with extreme simplicity, without requiring the intervention of particularly trained personnel.
A programmable control unit connected to the actuators of the various operating units of the system described above allows the operations described above to be performed automatically. The simplified block diagram of FIG. 14 represents a possible configuration of a control mechanism comprising a programmable control unit (UE) connected to the sensors (101) and to the actuators of the gripping means (1), of the belts (31), of the hooking belt (40), and of the cutting means (5). In the previous description of a possible operating cycle of the machine, the case has been exemplified that the cutting means (5) produce on the belt (W) a substantially triangular-shaped flap (TW) in the hypothesis that the rotation speed of the fixed roller (10) and the translation speed of the mobile support (51) are constant. However, the cutting means (5) can produce a cut of the web (W) having a profile different than a triangular profile (TW). For example, the cut produced by said means (5) can be such as to create on the web (W) a flap with a profile defined by two consecutive cutting lines having different inclinations, as schematically represented in FIG. 15 and FIG.16. In this case, by rotating the fixed roller (10) with constant speed, the mobile support (51) is initially translated with a first speed producing the cutting line (T1), then it is translated with a second speed higher than the first speed producing the cutting line (T2), and finally it is translated with a third speed comprised between the first and second speed producing the cutting line (T3). As shown in FIG. 15, the cutting lines (T1, T2, T3) produced on the web (W) are consecutive and have different inclinations with respect to the transversal direction (CD) of the web (W). The dashed part (DW) in FIG. 15 represents the part of the web (W) that is separated due to the cut. Whatever the chosen cutting cut profile, the front part of the web (W) to be hooked is given a predefined, precise and programmable shape, which drastically reduces the possibility of web jams downstream of the lateral hooking area, and this regardless of the paper grammage.
By accepting to perform the hooking of a paper web with the front edge not cut as described above, or with the front edge cut or prepared manually, possibly even before positioning the reel in the machine that uses it, the aforementioned cutting means could be omitted.
From the description provided it is evident that, more generally, a system according to the present invention comprises:
- gripping means (1) configured to engage a web (W) of paper material to control its movement according to a predetermined advancement direction (WF);
- a structure (2) for supporting said gripping means (1);
- hooking means (4) adapted to temporarily hook a lateral edge (SW) of the web (W), said hooking means being arranged downstream of the gripping means (1) with respect to the aforementioned advancement direction (WF); and
- said hooking means (4) comprise a flexible member (40) provided with tips (46) adapted for engaging the lateral edge (SW) of the web (W) while the same flexible member (40) is moved along a path (P4) which has a first section (PH) and a second section (PT), the flexible member (40) being mounted on a support (41) that can be moved between a hooking position in which the first section (PH) overlaps a path (PW) followed by the lateral edge (SW) of the web (W) and an inoperative position in which said first section (PH) is spaced from the path (PW) followed by the lateral edge (SW) of the web (W), and the second section (PT) of the path (P4) is a section along which the web (W) moves away from the point where it is hooked.
Preferably, the system comprises cutting means (5) adapted to transversely cut the web (W), arranged upstream of said hooking means (4) with respect to the aforementioned direction of advancement (WF), said cutting means being constrained to a respective movable support (51) which moves them transversely to the direction (WF) of advancement of the web (W) and being activated when the hooking means (4) engage the lateral edge (SW) of the web (W).
In accordance with preferred embodiments of the present invention, the flexible member (40) is a belt and the tips (46) are nails inserted in the belt.
Said belt (40) can be a belt with a rectangular cross section, or a belt with longitudinal grooves, or a belt with a trapezoidal cross section.
The tips (46) can be distributed over the entire length of the belt (40) or, alternatively, they can be distributed over predetermined portions of the belt (40) so as to form portions of hooking surfaces. Preferably, the hooking means (4) comprise a presser (42) acting on the lateral edge (SW) of the web (W).
According to a preferred embodiment of the present invention, the presser (42) consists of a brush located on the opposite side of the belt (40) with respect to the path (PW) followed by the lateral edge (SW) of the web (W).
Furthermore, preferably, said cutting means (5) comprise a blade (50) mounted on the mobile support (51) which, in turn, is mounted on a rectilinear guide (2G) arranged on said structure (2) and is controlled by a respective actuator (52). In accordance with the examples described above, said structure (2) comprises two uprights (20) joined at the top by a crosspiece (21) and said rectilinear guide (2G) is arranged on the crosspiece (21).
Preferably, the blade (50) is mounted on a lever (5L) controlled by a respective pneumatic actuator (55) mounted on the mobile support (51), and the actuator (55) allows to move the blade to and from the gripping means (1).
Furthermore, preferably, on the actuator (55) is hinged a corresponding end of the lever (5L) and the blade (50) is mounted on the other end of the lever (5L).
Again, preferably, the assembly formed by the blade (50), the actuator (55) and the lever (5L) is integral with an arm (54) rotatably constrained to the mobile support (51). It is understood that the system described above can be used not only to guide a web out of an unwinder but, more generally, it can be used in all cases in which it is required to guide a web of paper material by temporarily hooking it to a dragging member which guides it in a predefined direction. For example, the present guide system with temporary hooking of the lateral edge of a paper web can also be inserted downstream of an unwinder, for example upstream of an embosser (not shown in the drawings) to obviate possible breakage of a paper web material at a point inside a paper converting line.
In practice, the details of execution can in any case vary in an equivalent manner as regards the individual elements described and illustrated, without thereby departing from the idea of the solution adopted and therefore remaining within the limits of the protection granted by this patent in accordance with the attached claims.
Patent Application
20240336450
