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:
Reduced to its essential structure and with reference to
Preferably, the cutting means (5) are arranged in proximity to the gripping means (1).
With reference to the embodiment example shown in
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
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
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
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
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
The release mechanism shown in
The release mechanism shown in
The release mechanism illustrated in
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
A possible operating cycle of the guide system described above, with reference to the application example illustrated in
As shown in
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
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
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
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:
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).
Preferably, in accordance with the examples described above, 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.
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.
Number | Date | Country | Kind |
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102021000018890 | Jul 2021 | IT | national |
Filing Document | Filing Date | Country | Kind |
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PCT/IT2022/050187 | 6/28/2022 | WO |