Method and device for automatically connecting rolls of a web material

Abstract

An apparatus for automatically joining rolls of web material, the apparatus comprising a joining assembly (5) adapted to pick up a trailing edge of an imminent first roll (21) of web material (2) and to apply the trailing edge to a leading edge of a second roll (22) of web material. The leading edge is held close to a second roll (22) of web material via an attachment device (3) rotating at the same angular velocity as the second roll (22). The leading edge carries a label (4) of adhesive material on the outwardly facing side.

Description

Technical Field

[0001] The invention relates to a method for automatically linking rolls of web material and a device for implementing the method, in particular suitable for use in a device capable of automatically changing rolls of web material. Background Art

[0002] At present, in various technical fields, the use of automated machines for manufacturing or packaging products using rolls of web material is widely known. The operation of these automated machines implies the replacement of the roll being used when the web material has been completely exhausted.

[0003] Therefore, devices have been developed that are suitable for automatically replacing rolls of web material without interrupting the normal operating cycle of the machine. These devices essentially connect the trailing edge of the roll that is about to be exhausted with the leading edge of the new roll. Therefore, a responsible operator needs to regularly supply the device with one or more new rolls of web material; then, the device automatically replaces the running roll when it is completely exhausted.

[0004] Devices for automatically changing rolls of web material are known, for example, from patents EP 0 619 231 and EP 2 233 399.

[0005] Depending on the type of production, this operation may need to be performed relatively frequently. In particular, in certain production areas, such as the construction of electrical energy storage devices, a single roll of web material may be consumed within a few minutes, so that the replacement of the roll must be repeated at a high frequency.

[0006] Therefore, there is a need in certain production fields to speed up the operation of automatically joining the trailing edge of a expiring reel with the leading edge of a new reel without damaging the sometimes very thin web material during this operation.

[0007] In practice, in certain production areas, such as the manufacture of electrical energy storage devices, the strip of web material has, at least on one side, a series of outer ends or marks which are susceptible to bending or damage when in contact with a surface. This obviously results in an unacceptable amount of waste during the production phase.

[0008] Finally, the development of increasingly powerful automated machines capable of reaching very high production speeds has made it imperative that rolls of web material be changed just as quickly. This requires in particular that the joining of the trailing edge of the exhausted roll to the leading edge of the new roll be performed automatically at high speed in order to continuously feed the machine with web material. Summary of the invention

[0009] The object of the present invention is to solve the above mentioned problems by devising a method allowing to achieve an optimal automatic linking of rolls of web material in an apparatus for changing said rolls of web material associated with a machine for manufacturing or packaging products using the web material.

[0010] A further object of the invention is to provide a method for automatically linking rolls of web material which ensures that high production speeds are achieved.

[0011] It is a further object of the present invention to provide a method for automatically joining rolls of web material while maintaining the integrity of the web material.

[0012] A further object of the invention is to provide an apparatus capable of implementing the subject method of automatically joining rolls of web material, which apparatus is of simple structural and functional design, is provided with reliable operation, is widely applicable and has a relatively low cost.

[0013] According to the invention, the above object is achieved by a method for automatically joining rolls of web material according to claim 1 and by a device for automatically joining rolls of web material according to claim 2 .

[0014] An apparatus for automatically joining rolls of web material comprises a joining assembly adapted to pick up a trailing edge of a first roll of web material that is about to expire and apply the trailing edge to a leading edge of a second roll of web material.

[0015] According to one aspect of the invention, the leading edge of the second roll of web material is held close to the second roll via gripping means rotating at the same angular speed as the second roll of web material.

[0016] Suitably, said leading edge of the second roll of web material carries a label of adhesive material on an outwardly facing side.

[0017] Preferably, the attachment means comprises a radial arm provided with a support member at a free end, the support member being adapted to be connected to suction means to subject an outwardly facing surface of the support member to a vacuum, the radial arm being mounted to the axis of the drum and thereby rotating at the same angular velocity.

[0018] Preferably, the support comprises blades extending in a plane tangential to the outer surface of the roll of web material.

[0019] Preferably, the attachment means is operable in a radial direction of the rolls of web material to facilitate application of the leading edge of the second roll of web material to the trailing edge of the first exhausted roll of web material.

[0020] Preferably, the joining assembly comprises a plurality of rollers which are rotatable in a suitable phase relationship according to respective rotation axes parallel to the rotation axes of the rolls, so as to sequentially attach the web material unwound from the first roll, cut the trailing edge of the first roll, transfer the trailing edge of the first roll to the leading edge of the second roll, and join the trailing edge to the leading edge using a label of the adhesive material.

[0021] Suitably, the rollers counter-rotate relative to each other.

[0022] Preferably, the linking assembly comprises a first roller for picking up and unwinding the web material, the first roller being connectable to a suction device to place a circumferential surface of the first roller under vacuum to hold the web material unwound from the first reel.

[0023] Preferably, the connecting assembly comprises a second roller located downstream of the first roller in the advancing direction of the web material, the second roller being used to transfer the trailing edge of the first roll to the leading edge of the second roll, the second roller carrying a device for cutting the web material unwound from the first roll and suitable for defining the trailing edge.

[0024] Preferably, the cutting means comprises a blade housed in a seat formed radially in the body of the second roller, the blade being adapted to be actuated between an inactive, retracted position and an advanced position extending from the second roller for performing cutting of the web material.

[0025] Preferably, the connecting assembly includes a third roller located downstream of the second roller, the third roller being used to drive the web material to be supplied after the leading edge of the second roll is connected to the trailing edge of the first roll, and the third roller can be connected to a suction device to make the outer peripheral surface of the third roller under vacuum.

[0026] Suitably, said first roll of web material and said second roll of web material are arranged in respective working positions arranged side by side and in a co-planar manner, supported by respective motorised coupling members for rotation according to parallel axes.

[0027] Conveniently, the coupling assembly is carried by a movable assembly adapted to translate the coupling assembly in the axial direction of the roller by a stroke greater than the thickness of the web material.

[0028] Preferably, the movable assembly is movable between an operative position in which the movable assembly is coplanar with the first roll of web material and the second roll of web material and a retracted position in which the attachment assembly is not engaged with the web material unwound from the rolls.

[0029] Preferably, the movable assembly enables angular rotation of the coupling assembly between a first working position and a second working position, the first working position and the second working position being mirror images relative to each other.

[0030] The invention also relates to a method for automatically linking rolls of web material, the method comprising the following steps:

[0031] a. a second roll of web material is arranged in a working position in parallel with the working position of the first roll of unwinding web material to uniformly feed the web material, the first roll and the second roll being rotatable relative to parallel axes of rotation;

[0032] b. associating the leading edge of the second roll of web material with an attachment device operated to rotate by the second roll of web material (22), the leading edge carrying an adhesive device (4) on the side facing outwards;

[0033] c. detecting the remaining diameter of the first roll of the unwinding web material by means of a sensor device;

[0034] d. rotating the second roll of web material when a predetermined remaining diameter of the first roll of unwinding of the web material is detected;

[0035] e. cutting the rear edge end of the unwinding of the first roll of the web material;

[0036] f. engaging the trailing end of the first roll of the web material with a coupling assembly, the coupling assembly being arranged downstream of the first roll in the feed direction of the web material;

[0037] g. applying the trailing end of the first roll of web material to the leading edge of the rotating second roll of web material by means of the attachment means integral with the second roll of web material,

[0038] h. joining said trailing end of said roll of web material to said leading edge of said roll of web material by said adhering means associated with said leading edge of said second roll.

[0039] The subject method provides for rotating a second roll of web material at a peripheral speed which corresponds approximately to the speed at which said web material is fed to a machine using said web material.

[0040] According to aspects of the invention, the method provides for engaging the trailing edge of a first roll of the web material with a plurality of rollers of the joining assembly, the rollers being rotatable in a suitable phase relationship according to respective rotation axes parallel to the rotation axes of the rolls, thereby sequentially performing the attachment of the web material unwound from the first roll, cutting the trailing edge of the first roll, transferring the trailing edge of the first roll to the leading edge of the second roll, and joining the trailing edge to the leading edge by means of a label of the adhesive material.

[0041] According to another aspect of the invention, the method involves, at the end of the step of joining the trailing edge of the roll to the leading edge of the roll, translating the joining assembly from an operative position coplanar with the first roll of web material and the second roll of web material to a retracted position in which the rollers of the joining assembly are not engaged with the web material unwound from the rolls.

[0042] Conveniently, in the retracted position of the joining assembly, the method provides for angularly rotating the joining assembly between first and second working positions which are mirror images relative to each other so as to prepare the rollers for a subsequent joining operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Details of the invention will become more apparent from the detailed description of a preferred embodiment of an apparatus for automatically joining rolls of web material, illustrated by way of example in the accompanying drawings, in which:

[0044] Figure 1 is a side view of an apparatus for automatically linking rolls of web material according to the present invention;

[0045] Figure 2 yes Figure 1 An enlarged portion of the device shown in;

[0046] Figure 3 and Figure 4 are a side view and a front view of a portion of the device, respectively;

[0047] Figures 5 to 12 A schematic side view of the device is shown in a subsequent operating step. DETAILED DESCRIPTION

[0048] With particular reference to the drawings, an apparatus for automatically linking rolls of web material is indicated as a whole by reference numeral 1. In particular, in the drawings, reference numerals 21 and 22 refer to a first unwinding roll of web material 2 for feeding said web material 2 to an automatic machine that uses said web material 2 for production purposes, and a second roll of web material 2, respectively, which replaces the first roll when it is exhausted. In the following, for the sake of simplicity, the rolls 21, 22 are also referred to as running rolls and new rolls.

[0049] Within the scope of the invention, automatic linking of rolls of web material means linking of the trailing edge of an exhausted roll with the leading edge of a new roll so that the feed of web material to the machine is continuous.

[0050] The rolls 21, 22 of web material are adapted to be supported by a frame of the apparatus, in a manner known in the art and not shown in the drawings, in a substantially coplanar working position and with respective parallel axes of rotation. Preferably, said axes of rotation are horizontal.

[0051] Obviously, pairs of reels of web material of different types may be arranged on the frame of the apparatus so as to be fed simultaneously into the machine.

[0052] The rolls 21, 22 of web material are adapted to be inserted in a known manner onto respective coupling members which are set in rotation by specific drive members. The coupling members consist essentially of a cylindrical central piece 10 with which a tube or shaft 23 of the roll of web material is adapted to engage.

[0053] According to the invention, an attachment member 3 of the leading edge of the web material is associated with each roll of web material. In a preferred embodiment, said attachment member 3 consists of a radial arm 30 provided at a free end with a vane 31 adapted to be connected to a draw device for placing the surface of the vane 31 facing the outside of the roll under vacuum (see Figure 3 and Figure 4 ). The radial arm 30 is mounted on the axis of the drum and rotates therewith at the same angular speed.

[0054] The vacuum blade 31 is adapted to hold the leading edge of the web material, carrying the label 4 of adhesive material on the side facing the outside of the roll.

[0055] Conveniently, the application member 3 is adapted to be driven in a radial direction of the rolls of web material, as described below, to facilitate application of a leading edge of a second roll of web material to the trailing edge of a first, exhausted roll of web material.

[0056] The device 1 comprises a coupling assembly 5 adapted to take the trailing edge of a first running reel 21 when it is almost exhausted and to apply this trailing edge to the leading edge of a second reel 22 carried by the blade 31 of the attachment member 3 and carrying a label 4 with adhesive material (see Figure 2 ). The coupling assembly 5 comprises a plurality of rollers which are rotatable in a suitable phase relationship according to respective rotation axes parallel to the rotation axes of the reels 21, 22. It may be provided that the rollers have a rubberized outer surface for better adhesion to the web material.

[0057] Conveniently, the rollers of the hitch assembly 5 are arranged to be co-planar and counter-rotating relative to each other.

[0058] In particular, the linking assembly 5 comprises a first roller 51 for unwinding the web material 2, which can be connected to a suction device so that the outer peripheral surface of the first roller 51 is under vacuum during operation, thereby holding the web material 2 unwound from the first reel 21.

[0059] Downstream of the first unwinding roller 51, according to the advancing direction of the web material 2, a second roller 52 is arranged for transferring the trailing edge of the first reel 21 to the leading edge of the second reel 22. A device 6 for cutting the web material 2 unwound from the first reel 21 is suitable for defining the trailing edge, and the device 6 is carried on the second transfer roller 52. In a preferred embodiment, the cutting device 6 is constituted by a blade 60, which is housed in a seat 61 formed radially in the body of the second roller 52. The blade 60 is operable between a retracted position of inactivity and an advanced position in which it is extended from the second roller 52 to cut the web material 2.

[0060] A third roller 53 is arranged downstream of the second conveying roller 52 for driving the web material 2 to be fed to the machine after the leading edge of the second reel 22 is coupled to the trailing edge of the first reel 21. The third driving roller 53 can be connected to a suction device so that the peripheral surface of the third driving roller 53 is under vacuum during operation.

[0061] As will be described in more detail below, the linking assembly 5 is carried by a movable assembly, not shown in the figures, which is adapted to arrange the positions of the rollers 51, 52, 53 according to the arrangement of the web material being unwound. In particular, the movable assembly is adapted to translate the linking assembly 5 in the axial direction of the rollers 51, 52, 53 by a stroke whose width is greater than the thickness of the web material 2, and to rotate the linking assembly 5 according to a horizontal axis parallel to the axes of the rollers 51, 52, 53 between a first working position and a second working position of mirror images.

[0062] The operation of the apparatus for automatically joining rolls of web material can be readily understood from the following description.

[0063] When it is detected via a specific sensor device known in the art that the diameter of the running reel 21 has reached a predetermined value, ie, the running reel 21 is about to be exhausted within a predetermined period of time, the rotation of the new reel 22 previously set in the working position is operated.

[0064] It should be noted that at this stage the counter-rotating rollers 51, 52, 53 of the linking assembly 5 are arranged in a working position coplanar with the reels 21, 22 of web material. Suitably, the rollers 51, 52, 53 also have the same peripheral speed. The web material 2 unwound from the first reel 21 sequentially engages the rollers 51, 52, 53 of the linking assembly 5 and extends freely between the rollers 51, 52, 53, as in Figure 1 can be seen in.

[0065] The second drum 22 is rotated at a peripheral speed substantially equal to the unwinding speed of the web material 2 of the first drum 21. In this step, the leading edge of the web material of the second drum 22 is wound and held close to the outer surface of the second drum 22 by the vacuum blade 31 of the attachment member 3 operating in a manner rotating integrally with the second drum 22.

[0066] When it is detected that the first reel 21 is about to be exhausted, the suction device is activated, which makes the outer surface of the first roller 51 in vacuum. In this way, the web material 2 is held on the vacuum outer surface of the first roller 51.

[0067] In an appropriate phase relationship, the cutting device 6 carried by the second conveying roller 52 is in a radial position ( Figure 5 ). At this point, the blade 60 performing the cutting of the web material 2 is activated. The cutting of the web material defines the trailing edge of the reel 21 downstream of the cutting line, which continues to move forward on the second roller 52 and then joins to the leading edge of the new reel 22, so that the supply of web material to the machine is continuous. The remaining web material upstream of the cutting line is then held on the first vacuum roller 51 and wound around it.

[0068] The synchronous rotation of the rollers 51, 52, 53 of the linking assembly 5 with the rotation of the new roll 22 allows the trailing edge of the first roll 21 to be brought in a suitable phase relationship ahead of the leading edge of the new roll 22, which is carried by the vacuum blade 31 of the attachment member 3 ( Figure 6 ). In this way, by means of the label 4 of adhesive material, the joining of the two edges of the rolls 21 , 22 is achieved.

[0069] Suitably, in order to facilitate this joining operation, it can be provided that the vacuum blade 31 of the attachment member 3 moves radially outwardly by a very limited amplitude to press the leading edge of the label 4 with adhesive material of the new roll 22 against the trailing edge of the first roll 21 carried by the second roller 52.

[0070] After the two edges of the reels 21, 22 are joined, the web material 2 continues to travel on the third drive roller 53 to be unwound from the second reel 22 ( Figure 7 ). In practice, the web material 2 is stretched between the second drive roller 52 and the third drive roller 53 by a pressure which can be adjusted appropriately to prevent the web material 2 from stretching relative to the rollers 52, 53. The web material 2 between the second roller 52 and the third roller 53 also has the function of compressing the label 4 of the adhesive material to ensure the attachment of the label 4 of the adhesive material.

[0071] After the coupling of the roll of web material is completed, the movement of the movable assembly is initiated, which brings the coupling assembly 5 into the retracted position in order to disengage the web material 2 and rotates the coupling assembly 5 itself about a horizontal axis into an operating position mirroring the previous operating position (see Figures 8 to 11 ).

[0072] At the same time, the exhausted roll is automatically removed from the central piece 10 in a known manner and the subsequent new roll 24 is inserted in its place ( Fig.12 ). It should be noted that in the new configuration, the rollers of the linking assembly 5 are turned towards the second reel 22, in a position mirroring the previous position, i.e. rotated 180°. Thus, the device is ready for the subsequent operation of linking the reels to ensure a continuous supply of web material to the machine.

[0073] The method and the device for automatically linking rolls of web material according to the invention achieve the object of optimally performing the automatic linking of rolls of web material in a machine for producing or packaging products using such web material.

[0074] In particular, it has been verified that the method and the device according to the invention for automatically linking rolls of web material make it possible to ensure high operating speeds, so that the supply of web material is continuous even in machines configured to operate at very high speeds.

[0075] This is due to the innovative idea of ​​equipping the roll of rolled web material with an attachment member capable of keeping the leading edge of said rolled web material close to the outer surface of the roll, which carries adhesive means suitable for joining the trailing edge of the roll that is about to be exhausted, and to the innovative idea of ​​preparing a joining assembly which, by a specific command, is able to detach the trailing edge of the rolled web material from the roll that is about to be exhausted and apply it to the end of a new roll to perform automatic joining.

[0076] Another characteristic of the invention is that the described device allows preparing the joining assembly for the subsequent step of changing the reel during the feeding of the web material by the running reel, thus avoiding stops or slowdowns in the joining of the edges of the reel and thus making the feeding of the web material to the machine continuous.

[0077] In practice, the device is adapted to the operating speed of the machine, since the joining of the reel edges and therefore the replacement of the reels themselves are performed on a web material being unwound at the feed speed set by the machine.

[0078] The device described by way of example is capable of numerous modifications and variations according to different requirements.

[0079] In the actual implementation of the present invention, the materials used as well as the shapes and sizes can be modified according to requirements.

[0080] If any technical features mentioned in any claim are followed by reference numerals, these reference numerals are included merely to enhance the understanding of the claims and should not be considered in any way as limiting the scope of each element exemplarily identified by these reference numerals.

Claims

1. A method for automatically joining rolls of web material, characterized in that: The method comprises the following steps: a. arranging a second roll (22) of web material in a working position in parallel with the working position of a first roll (21) of unwinding the web material (2) to feed the web material (2) in unison, the first roll (21) and the second roll (22) being rotatable about parallel rotation axes; b. associating the leading edge of the second roll (22) of web material with the attachment means (3) operated to rotate via the second roll (22) of web material, the leading edge carrying the adhesion means (4) on the side facing outwards; c. detecting the remaining diameter of the first roll (21) of the unwinding of the web material by means of a sensor device; d. when a predetermined remaining diameter of the unwound first roll (21) of the web material is detected, rotating the second roll (22) of the web material; e. cutting the trailing edge of the unwinding first roll (21) of the web material; f. engaging the trailing edge of the first roll (21) of the web material with a connecting assembly (5), the connecting assembly (5) being arranged downstream of the first roll (21) in the feeding direction of the web material (2); g. applying the trailing edge of the first roll (21) of web material to the leading edge of the rotating second roll (22) of web material by means of the attachment device (3) which is integral with the second roll (22) of web material, h. connecting the trailing end of the roll (21) of web material to the leading edge of the roll (22) of web material by means of the adhesive means (4) associated with the leading edge of the second roll (22).

2. A device for automatically joining rolls of web material, the device comprising a joining assembly (5) adapted to pick up the trailing edge of a first roll (21) of the web material (2) that is about to be exhausted and apply the trailing edge to the leading edge of a second roll (22) of the web material, the leading edge being held close to the second roll (22) of the web material by means of an attachment device (3) rotating at the same angular speed as the second roll (22) of the web material, and the leading edge carrying a label (4) of adhesive material on the side facing outwards.

3. The device according to claim 2, wherein: The attachment device (3) comprises a radial arm (30) provided with a blade (31) at a free end, the blade (31) being connectable to suction means so that the outwardly facing surface of the blade (31) is under vacuum, the radial arm (30) being mounted on the axis of the drum (22) and therefore rotating at the same angular speed.

4. The device according to claim 2 or 3, wherein: The connecting assembly (5) comprises a plurality of rollers (51, 52, 53), which are capable of rotating in a suitable phase relationship according to corresponding rotation axes parallel to the rotation axes of the rolls (21, 22), so as to sequentially attach the web material (2) unwound from the first roll (21), cut the trailing edge of the first roll (21), transfer the trailing edge of the first roll (21) to the leading edge of the second roll (22), and connect the trailing end to the leading edge by means of a label (4) of the adhesive material.

5. The device according to any one of claims 2 to 4, wherein: The connecting assembly (5) comprises a first roller (51) for attaching the web material (2) and unwinding the web material (2), wherein the first roller (51) can be connected to a suction device so that the outer peripheral surface of the first roller (51) is in a vacuum, thereby holding the web material (2) unwound from the first reel (21).

6. The device according to claim 5, wherein: The connecting assembly (5) comprises a second roller (52) located downstream of the first roller (51) in the traveling direction of the web material (2), the second roller (52) being used to transfer the trailing edge of the first roll (21) to the leading edge of the second roll (22), and the second roller (52) carrying a device (6) for cutting the web material (2) unwound from the first roll (21) and suitable for separating the trailing edge.

7. The device according to claim 6, wherein: The cutting device (6) comprises a blade (60) housed in a seat (61) formed radially in the body of the second roller (52), the blade (60) being operable between a retracted position of inactivity and an advanced position extending from the second roller (52) for cutting the web material (2).

8. The device according to claim 7, wherein: The connecting assembly (5) comprises a third roller (53) located downstream of the second roller (52), and the third roller (53) is used to drive the web material (2) to be supplied after the leading edge of the second roll (22) is connected to the trailing end of the first roll (21), and the third roller (53) can be connected to a suction device so that the outer peripheral surface of the third roller (53) is in a vacuum.

9. The device according to any one of claims 4 to 8, wherein: The connecting assembly (5) is held by a movable assembly, which is suitable for translating the connecting assembly (5) in the axial direction of the rollers (51, 52, 53) by a stroke, the width of which is greater than the thickness of the web material (2).

10. The device according to any one of claims 4 to 9, wherein: The connecting assembly (5) is carried by a movable assembly, which is suitable for rotating the connecting assembly (5) according to a vertical axis between a first working position and a second working position, the first working position and the second working position being mirror images relative to each other.

Images