AUTOMATIC METHOD FOR SPLICING PREPARATION AND SYSTEM FOR CARRYING OUT SAME

Abstract

An automatic splice preparation process for splicing between two rolls of a material in web format, such as paper, and a system for carrying out same, wherein the positioning system for positioning the paper web of the new roll is displaced automatically by a robotic arm, the displacement of which is verified and corrected through machine vision device, to locate and capture the edge of the web in a controlled manner. The robotic arm is provided with a head incorporating the machine vision device and gripping areas, such that the movement of the assembly established by a program, verified and corrected, if needed, through the signals generated by machine vision system which are preferably made up of at least three machine vision cameras positioned in the central area and at the ends of the head.

Claims

1. An automatic splice preparation process for splicing between rolls of a material in web format, comprising a positioning system for positioning the material in web format of a new roll is displaced automatically by means of a system of controlled positioning actuators comprising a robotic arm, the displacement of which is established by a program and verified and corrected, if needed, through machine vision means, also used to locate and capture an edge of the material in web format in a controlled manner.

2. The automatic splice preparation process according to claim 1, wherein the positioning system positions in an automatic and controlled manner the material in web format of the new roll on a cutting area, so as to proceed to completely cut the initial segment of the material in web format, in a direction perpendicular to the material unwinding direction

3. The automatic splice preparation process according to claim 1, wherein by means of the machine vision means, the positioning system automatically proceeds to the positioning and placement of an adhesive tape.

4. The automatic splice preparation process according to claim 1, wherein the positioning phase for positioning the material in web format of the new roll, a head of the robotic arm moves closer up to a pre-established distance from the new roll, leaving sufficient space for a field of view established for the machine vision means, such that they detect the edge of the new roll.

5. The automatic splice preparation process according to claim 1, wherein the positioning phase for positioning the material in web format of the new roll, the new roll starts to turn until a central camera of the machine vision means detects a line feed of a laser indicating that it has found the edge of the new roll, with the rotation of the new roll then stopping, and when the position of the new roll has been assured, the head of the robotic arm captures an upper layer of the material in web format of the new roll and by knowing where the edge thereof is located, transfers it to the cutting area.

6. The automatic splice preparation process according to claim 3, wherein the adhesive tape is pre-cut when the head of the robotic arm is positioned above same to verify a length thereof with the corresponding machine vision means, to match the dimensions and the edges of the adhesive tape to the desired measurement.

7. The automatic splice preparation process according to claim 3, wherein when the position of the adhesive tape has been assured, with the corresponding machine vision means of the head, the position of both corners of the cut edge of the new roll is observed in order to know the position thereof, and upon capturing this area of the edge, align it with the material in web format of a feed roll and with respect to the new roll and to also align it with the correct position of the edge on the adhesive tape.

8. A system for carrying out the automatic splicing process, comprising a system of controlled positioning actuators provided with a head incorporating machine vision means and gripping means, such that the movement of the assembly is established by means of the corresponding program and verified and corrected, if needed, by means of the signals generated by the machine vision means.

9. The system for carrying out the automatic splicing process according to claim 8, wherein the machine vision means of the head are made up of at least three machine vision cameras, of those camera is positioned in the central area and cameras are positioned at the ends of said head.

10. The system for carrying out the automatic splicing process according to claim 8, wherein the central camera is arranged at an angle with a laser which is used for the detection of the edge of the new roll.

11. The system for carrying out the automatic splicing process according to claim 8, wherein the head has gripping areas, optionally three in number, one of them being located in the central part and the other two at the sides.

12. The system for carrying out the automatic splicing process according to claim 11, wherein according to a preferred embodiment the gripping areas can act separately or together and each of them is made up of a vacuum sector and a suction cup sector.

13. The system for carrying out the automatic splicing process according to claim 8, wherein a dolly and a row of suction cups with a vacuum to capture the remaining paper that will be disposed of after the cutting are arranged at the lower edge of the head, whereas a hold-down plate is arranged at its upper edge.

Description

DESCRIPTION OF THE FIGURES

[0035] FIG. 1 is a schematic perspective view of the elements forming part of the splicing system object of the present invention according to a practical, non-limiting, exemplary embodiment, and being formed by a vacuum and cutting table (1), a preparation and splicing table (2) and a robotic arm (3), with the head (5) of the robotic arm (3) being depicted on the vacuum and cutting table (1).

[0036] FIG. 2 is the elevational view corresponding to FIG. 1.

[0037] FIG. 3 is a view like that of FIG. 1, but in this case with the head (5) positioned above the preparation and splicing table 2.

[0038] FIG. 4 is the elevational view corresponding to FIG. 1.

[0039] FIG. 5 is a view like that of FIG. 1, but in this case depicting the rolls to be spliced (6 and 7).

[0040] FIG. 6 is the elevational view corresponding to FIG. 1.

[0041] FIG. 7 is a view like that of FIG. 3, but in this case depicting the rolls to be spliced (6 and 7).

[0042] FIG. 8 is the elevational view corresponding to FIG. 7.

[0043] FIG. 9 is an elevational view schematically showing the arm of the robotic arm (3) according to four working positions; the first position with its head (5) in contact with the new roll (6); the second position with the head (5) positioned above the vacuum and cutting table (1); the third position with the head (5) positioned in correspondence with the preparation and splicing table (2); and the fourth position with the head (5) in connection with the support structure (23) for the adhesive tape (10).

[0044] FIG. 10 is a perspective view of the robotic arm (3).

[0045] FIG. 11 shows in detail the head (5) of the robotic arm (3).

[0046] FIG. 12 corresponds to a bottom plan view of the head (5).

[0047] FIG. 13 is a front elevational view of the head (5).

[0048] FIG. 14 corresponds to a top plan view of the head (5).

[0049] FIG. 15 is a top plan view of the vacuum and cutting table (1).

[0050] FIG. 16 is a schematic perspective view showing the robotic arm (3) moving closer to the new roll (6), with the vacuum and cutting table (1) and the preparation and splicing table (2) having been removed so as to not hinder viewing. The feed roll (7) is not depicted for the same reason.

[0051] FIG. 17 is an elevational view like that of FIG. 10, but with the head (5) now in contact with the paper web (6.1) of the roll (6).

[0052] FIGS. 18 and 19 are respective details showing the pressure rollers (1) in contact with the new roll (6) and separated from same, respectively.

[0053] FIG. 20 is a perspective view showing the head (5) of the robotic arm (3) depositing the paper web (6.1) of the new roll (6) on the vacuum and cutting table (1).

[0054] FIG. 21 is an elevational view corresponding to FIG. 20.

[0055] FIG. 22 is a perspective view of a detail of the head (5) with the paper web (6.1) of the new roll (6) having been deposited on the vacuum and cutting table (1).

[0056] FIG. 23 shows a perspective view of the cutting phase for cutting the paper web (6.1) of the new roll (6).

[0057] FIG. 24 is an elevational view of the same phase of the process depicted in FIG. 23.

[0058] FIG. 25 is a perspective view of a detail showing the head in the phase depicted in FIGS. 23 and 24.

[0059] FIG. 26 is a perspective view of a detail showing the head (5), with the excess piece (22) of paper web being taken from the new roll (6) once the cut has been made.

DETAILED DESCRIPTION OF THE INVENTION

[0060] The object of the invention relates to an automatic preparation and splicing process for two rolls of paper identified in the attached drawings with reference numbers (6 and 7),

[0061] To carry out this process, means and equipment are used where said means and equipment constitute a system which, according to a practical, non-limiting, exemplary embodiment is depicted in the attached figures and is made up of two tables (1 and 2) and a system of controlled positioning actuators, such as a robotic arm (3), provided with a head (5), with the corresponding tools, as can be seen in FIG. 1, such that the splicing of the two paper rolls (6 and 7) is automatically carried out with this equipment, with the roll (7) being what is referred to as the feed roll, as it is the roll that is being used in the corresponding work process, whereas roll (6) is identified as the new roll and is the roll that is prepared for being spliced to the previous roll when it is running out, see FIGS. 5, 6, 7 and 8.

[0062] The splice depicted in the attached drawings is an end-to-end splice, as this is the most complex splice, but the object of the invention is perfectly compatible with other splice types. As will be seen below, this process assures the alignment of paper webs and also assures that the preparation cut will comply with the requirements of a minimum gap preferably between 0 and 2 mm, but it may be different from that value if desired, the gap being the distance between the end edges of the two paper rolls (6 and 7) to be spliced.

[0063] The robotic arm (3) is assembled on rails (4) located along the machine centre axis on which it moves along the x-axis, to move closer to and away from the new roll (6) and the preparation, cutting and splicing area. This robotic arm (3) incorporates a head (5) where different means and elements needed for carrying out the splicing process are incorporated.

[0064] Gripping areas identified with reference number (8), see FIG. 11, preferably arranged three in number, are defined on the front face of the head (5) of the robotic arm (3). The two gripping areas (8), which are positioned at the ends, are capable of moving simultaneously, moving closer to or away from the central gripping area (8), such that they can be adapted to the needed roll width.

[0065] According to a practical, non-limiting embodiment, each of these three gripping areas (8) is made up of a vacuum sector (8.1) and a suction cup sector (8.2). The vacuum sectors (8.1) allow the paper to be trapped and adapted to the different roll and surface shapes, without the web being creased or folded.

[0066] The possibility of both the vacuum sector (8.1) and the suction cup sector (8.2) being made up of suction cups has been provided for, by providing controlled movement only to the suction cup sector (8.2). That is, instead of the vacuum sectors (8.1) having means which allow a vacuum to be established in order to grab the paper web, these means are replaced with suction cups which would perform one and the same function, or any other conventional means which allows that function to be established.

[0067] According to a practical, non-limiting, exemplary embodiment, each vacuum sector (8.1) is made up of a perforated sponge in order to generate the necessary vacuum. These perforated sponges are assembled in a support coupled to the fixed structure of the head (5) by means of feet equipped with a spring which establish an elastically damped assembly of the perforated sponges, as can be seen in FIGS. 11 to 14. As indicated in the preceding paragraph, these vacuum sectors (8.1) do not have to be configured based solely on perforated sponges, where they can be replaced with another type of vacuum means the function of which is the same as that of the perforated sponges or with other conventional means which allow that function to be performed.

[0068] As can be seen in FIG. 13, the suction cup sector (8.2) is determined by small suction cups arranged at the lower edge of each vacuum sector (8.1). By means of the corresponding cylinders, these suction cups can be displaced between respective stable positions.

[0069] Since the suction cup sectors (8.2) are actuated with cylinders, they can move outwards and inwards, such that these suction cup sectors (8.2) can protrude with respect to the other vacuum sectors (8.1) and can capture the corresponding adhesive tape (10) to be used in the splicing. However, if desired, this process could be performed without removing these suction cup sectors (8.2) and using the same vacuum sectors (8.1) to capture the adhesive tape (10) as those used to capture the paper, all depending on the type of adhesive tape (10) to be used.

[0070] Of these three gripping areas (8), the central area is provided with two pressure rollers (11), one above and one below, actuated by means of cylinders (12) that remove or draw them in, depending on process requirements. The support of each of these pressure rollers (11) is guided in displacement by means of respective cylindrical guides.

[0071] Machine vision cameras are also positioned in the head (5) of the robotic arm (3), said cameras being preferably three in number, indicated with reference numbers (14, 15 and 16), of those cameras (14 and 16) are located on the sides and camera (15) in the central area, as can be seen in FIG. 11. The robotic arm (3) moves to the points predetermined by the corresponding computer program and the side machine vision cameras (14 and 16) and the central camera (15) verify and correct the position of the robotic arm (3), if needed.

[0072] The central camera (15) is assembled next to the central gripping area (8), at an angle with a laser (17) which is used for the detection of the edge of the new roll (6). The side cameras (14 and 16) are assembled next to each side gripping area (8) and will move with same, such that for different web widths the side cameras (14 and 16) will see the same edge of paper without having to vary the focal length. These two side cameras (14 and 16) are in charge of aligning the paper web and verifying the length of adhesive tape (10).

[0073] A dolly (18) is arranged at the lower edge of the head (5) for the preparation cut for preparing the paper web (6.1) of the new roll (6). There is also arranged a row of suction cups (20) with a vacuum, see FIGS. 12 and 13, to capture the remaining paper (22) that will be disposed of after the cutting, and two pins (19) which, by means of their penetration in respective housings of the table (1), which are not depicted, will verify the position of the head (5) on the table (1) where cutting is performed to verify that the head (5) has been positioned correctly on the table (1), see FIGS. 23, 24 and 25.

[0074] Each suction cup (20) is assembled on a support shaft with a spring, such that an assembly of the suction cups (20) with elastic damping is established.

[0075] In the upper edge of the head (5), see FIGS. 11 and 13, there is arranged rubber sector or hold-down plate (21) which will secure the attachment between the paper web (6.1) and the adhesive tape (10) to assure the adhesion thereof.

[0076] As can be seen in FIG. 15, the table (1) has a perforated strip (1.1) in its upper part in order to generate the corresponding vacuum through same and a groove (1.3) for the passage of the cutting blades cutting the paper web (6.1) against the dolly (18) of the head (5) of the robotic arm (3). Said FIG. 15 also shows the existence of vacuum spillways identified with reference number (1.2) in the upper part of the table (1) to adapt the length of the vacuum which is established through the perforated strip (1.1) to different paper web widths. Therefore, this table (1) will be identified as a vacuum and cutting table (1).

[0077] The table (2) referred to as the preparation and splicing table (2) has a preparation bar (2.1), with a vacuum, on which the adhesive tape (10) used for splicing is deposited.

[0078] Though not depicted in FIGS. 10 to 26 of the attached drawings for the sake of a simple explanation, the vacuum and cutting table (1) and/or the preparation and splicing table (2) can be assembled on conventional structures which allow movement in a horizontal and/or vertical plane through known means. For example, there has been provided an assembly in a double bridge structure (9) which can be displaced in a horizontal plane and with the possibility of the vacuum and cutting table (1) and/or the preparation and splicing table (2) being able to move up or down along the vertical columns (13) of the bridge structure to move closer to or away from the rolls (6 and/or 7). This possible practical depiction is the one depicted in FIGS. 1 to 9 where it can be seen how tables 1 and 2 extend between the columns (13) with the possibility of being displaced in height along same, such that in the cutting phase table (1) can be above the splicing table (2) and vice versa in the splicing phase. Furthermore, and in the splicing between the rolls (6 and 7), the splicing table (2) can move up in search of the paper web (7.1) of the roll (7).

[0079] According to this practical, non-limiting, exemplary embodiment, it has even been provided for the tables (1 and 2) to extend between the columns (13) of the double bridge structure (9) or for each of them to protrude in cantilever fashion from a column (13).

[0080] According to the object of this invention, the process starts from having a new roll (6) prepared for splicing, already loaded and raised in a conventional device that allows it to be rotated in both directions. This new roll (6) will have the start of the paper web (6.1) in any one unknown position, towards which the arm of the robotic arm (3) will advance with its head (5) in the vertical position and with the three gripping areas (8) facing the new roll (6), as can be seen in FIG. 16.

[0081] In this phase of the process (11), the pressure rollers occupy the position of being removed, such that they protrude from the surface of the vacuum sectors (8.1).

[0082] The head (5) moves closer up to a pre-established distance, wherein the pressure rollers (11) are positioned on the surface of the new roll (6), but not the vacuum sectors (8.1), as can be seen in FIG. 17 and in the detail of FIG. 18, leaving sufficient space for the field of view established for the central camera (15) and for the laser (17), such that they detect the edge of the new roll (6).

[0083] The laser (17) draws a line on the paper web (6.1) of the new roll (6) and the central camera (15) plus the corresponding software are capable of correctly discriminating the data, retaining only the variation of the laser (17) that corresponds with the detection of the edge of the paper web (6.1) of the new roll (6).

[0084] The new roll (6) starts to turn until the central camera (15) detects the line feed of the laser (17) indicating that it has found the edge of the new roll (6), then rotation stops. At this point the pressure rollers (11) are withdrawn back to their stable drawn in position, as can be seen in FIG. 19, allowing the roll (6) to be rewound, causing the edge to move backwards or forwards (depending on how the roll (6) has been positioned) and out of the area enclosed by the pressure rollers (11). When this occurs, the roll (6) stops again and then the head of the robotic arm (5) moves closer, positioning the pressure rollers (11) and in turn the vacuum sectors (8.1). When the position is assured, the vacuum of the sectors (8.1) is activated, assuring that the upper layer of the paper web (6.1) of the new roll (6) has been captured and can be transported, knowing where the edge is located.

[0085] When the paper web (6.1) of the new roll (6) has been captured by the head (5) of the robotic arm (3), said head (5) transfers it to the vacuum and cutting table (1). At this point, the head (5) of the robotic arm (3) leaves the paper web (6.1) of the new roll (6) on the vacuum and cutting table (1), as can be seen in FIGS. 20 to 22, such that correct holding is assured and the next step can be performed, which consists of activating the vacuum of the table (1) and deactivating the vacuum of the vacuum sectors (8.1) of the head (5) of the robotic arm (3).

[0086] The cutting process is the preparation process for preparing the edge of the new roll (6). The cutting must be such that it allows end-to-end splicing with the required tolerances. When the head (5) of the robotic arm (3) has released the paper web (6.1) of the new roll (6) on the vacuum and cutting table (1), the robotic arm (3) is withdrawn to a position which allows it to rotate the head (5) to the vertical position, in which the dolly (18) is in the lower part.

[0087] In this position, the two pins (19) of the ends of the line of suction cups (20) are matched up to two corresponding housings located in the vacuum and cutting table (1). These housings are not depicted so as not to complicate unnecessarily the depiction of the figures in the attached drawings. With all this so arranged, it is verified that the head (5) has been correctly positioned on the vacuum and cutting table (1). The vacuum and cutting table (1) itself, through its cutting system with blades which could be any conventional cutting system, cuts the paper web (6.1) of the new roll (6) against the dolly (18) of the head (5) of the robotic arm (3). The cutting blades emerge and run along the groove (1.3) of the upper part of the vacuum and cutting table (1), see FIGS. 23 to 25.

[0088] When the cut has been made, the vacuum of the table (1) is deactivated and with the vacuum of the line of suction cups (20) of the head (5) of the robotic arm (3) activated, the remaining surplus (22) of the paper web (6.1) after cutting is grabbed, as depicted in FIG. 26, such that the head (5) and the robotic arm (3) are withdrawn to a pre-established position to deposit this remaining paper (22) as waste.

[0089] After having removed the remaining paper, the robotic arm (3) places its head (5) with its largest face arranged parallel to the corresponding adhesive tape (10) which will be prepared in the corresponding support structure (23) for said adhesive tape (10). The adhesive tape (10) in this case will be one-sided because end-to-end splicing is being performed, but if it were an overlap splice, the tape would be two-sided. The adhesive tape (10) must be pre-cut in the moment in which the head (5) of the robotic arm (3) is positioned above it, first to verify its length with the side machine vision cameras (14 and 16) which, aided by a ruler located along the deposited and cut adhesive tape (10), can match the dimensions and the edges of the tape (10) to the desired measurement. For this work it is not necessary for the central camera (15) to start operating, but it could, if needed, without this changing the essence of the invention at all.

[0090] In a later phase, the robotic arm (3) will pull out the suction cup sectors (8.2) of the gripping areas (8) that are actuated by a cylinder and intended for trapping the tape (10) by the face having the adhesive tape. When the adhesive tape (10) is captured in that way, it is taken to the preparation and splicing table (2), which is also provided with a vacuum. The adhesive tape (10) will be left duly centred on this preparation and splicing table (2) and its position will be assured by means of the side vision cameras (14 and 16), where the central camera (15) may optionally be used.

[0091] Once the position of the adhesive tape (10) on the preparation bar (2.1) has been assured, the robotic arm (3) is displaced from this preparation and splicing table (2) to capture the paper web (6.1) of the new roll (6) that has been left with the edge prepared on the vacuum and cutting table (1). The side vision cameras (14 and 16) are used to observe the position of both corners of the cut edge of the new roll (6) to know the position thereof, and by capturing it to align it the paper web (7.1) of the feed roll (7) and to align it with the correct position of the edge on the adhesive tape (10), so that when it is to be spliced with the feed roll (7) the minimum gap possible, or the minimum gap required, is produced. If the splice is an overlap splice, the position of the edge does not have to be as precise, but web alignment continues to be beneficial.

[0092] When the head (5) of the robotic arm (3) has verified the current position and compares it with that of the paper web (7.1) of the feed roll (7), it captures the edge of the paper web (7.1) of the new roll (6), such that it can correct the position, if needed, to then take it to the preparation and splicing table (2), where adhesive tape (10) will be waiting. By using visual references for the central vision camera (15) and/or the side vision cameras (14 and 16), the robotic arm (3) centres the edge of the paper web (6.1) of the new roll (6) and deposits it on the adhesive tape (10). The head (5) is subsequently placed perpendicularly to exert a fixing pressure on the attachment of both materials, by means of the hold-down plate (21).

[0093] Once this has been performed and according to a practical, non-limiting embodiment, the second vacuum and preparation table is displaced vertically in order to reach the area of the feed roll (7) that is running out and then perform the corresponding splicing.

[0094] With the splicing already performed and by conventional means, the new roll (6) will become the feed roll (7) and a new roll will be arranged to carry out the entire splicing process again when necessary.

[0095] The possibility of whether or not a fixing tape is used is left up to the process. The application of the fixing tape can either be done in a way similar to the adhesive splicing tape (10) or the device can be located in the head (5) of the robotic arm (3) and applied after placing the paper web (6.1) of the new roll (6) on the adhesive tape (10). This fixing tape can be used in cases where it is desired to assure that for a certain gap value in the space between the edges of the paper webs (6.1 and 7.1) of the rolls (6 and 7) to be spliced, the adhesive tape of the adhesive tape (10) does not come into contact with the rollers of the rest of the line.

[0096] Therefore, to start up the splicing process for splicing two rolls (6 and 7), the only data that must be input with each new roll (6) are the diameter of said roll, the thickness of the paper, the width of the web and the unwinding direction, in order to start up said process which is carried out automatically.