Apparatus and method to fetch an end portion of a sheet of material wound in a bobbin

Abstract

The invention relates to an apparatus (100) and a method to fetch an end portion of a sheet (40) of material wound in a bobbin (152), the apparatus including: a rotatable bobbin holder (150) adapted to be inserted in a bobbin; an articulated arm (180); a suction device (110) having a contact surface (124) including a first portion (130) capable of exerting a first suction power and a second portion (132) capable of exerting a second suction power different from zero, wherein the first suction power is higher than the second suction power, the suction device being attached to the articulated arm; and a control unit (190), adapted to command a movement of the articulated arm so that the first portion of the contact surface of the suction device contacts the bobbin. The invention also relates to a method to fetch an end portion of a sheet of material wound in a bobbin.

Claims

1. An apparatus to fetch an end portion of a sheet of material wound in a bobbin, the apparatus including: a rotatable bobbin holder adapted to be inserted in a bobbin; an articulated arm; a suction device having a contact surface including a first portion capable of exerting a first suction power and a second portion capable of exerting a second suction power different from zero, wherein the first suction power is higher than the second suction power, the suction device being attached to the articulated arm; and a control unit, adapted to command a movement of the articulated arm so that the first portion of the contact surface of the suction device contacts the bobbin.

2. The apparatus according to claim 1, including a diameter sensor, adapted to determine a diameter of the bobbin, the diameter sensor being electrically connected to the control unit so as to send to the control unit signals relative to the diameter of the bobbin.

3. The apparatus according to claim 1, including an angular speed sensor, adapted to determine an angular speed of the bobbin holder, the angular speed sensor being electrically connected to the control unit so as to send to the control unit signals relative to the angular speed of the bobbin holder.

4. The apparatus according to claim 1, including a guiding means positioned substantially parallel to the contact surface of the suction device and overlapping a part of the second portion, adapted to guide an end portion of the sheet of material between the contact surface of the suction device and the guiding means.

5. The apparatus according to claim 1, including a presence sensor positioned at the contact surface of the suction device, adapted to determine the presence of a sheet portion on the contact surface of the suction device.

6. The apparatus according to claim 1, wherein the suction device includes a conveyor belt.

7. The apparatus according to claim 1, wherein a width of the contact surface of the suction device at the first portion is wider than a width of the contact surface of the suction device at the second portion.

8. The apparatus according to claim 6, wherein the suction device includes three conveyor belts, positioned one laterally adjacent to the others, so as to define a central conveyor belt and two lateral conveyor belts, the central conveyor belt being longer than the lateral conveyor belts, the first portion of the contact surface of the suction device including a surface portion of the central conveyor belt and of the two lateral conveyor belts and the second portion of the surface of the suction device including a surface portion of the central conveyor belt only.

9. The apparatus according to claim 1, wherein the contact surface of the suction device is movable.

10. The apparatus according to claim 1, including a speed sensor adapted to determine a speed of the contact surface.

11. The apparatus according to claim 9, wherein the control unit is adapted to regulate a speed of the contact surface of the suction device depending on the speed of the bobbin holder.

12. The apparatus according to claim 1, wherein the articulated arm includes two points of articulation.

13. A method to fetch an end portion of a sheet of material wound in a bobbin, the method including: contacting with a suction device an external surface of a bobbin; sucking with a first suction power the contacted surface of the sheet so as to detach a sheet portion from the bobbin; and after detachment of the sheet from the bobbin, sucking with a second suction power the sheet portion which has been sucked with a first suction power, wherein the second suction power is lower than the first suction power.

14. The method according to claim 13, wherein contacting with the suction device an external surface of the bobbin includes contacting the external surface tangentially to the external surface.

15. The method according to claim 13, including: guiding the detached sheet portion within a passage formed in the suction device.

Description

(1) The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

(2) FIG. 1 shows in a simplified way an isometric view of a part of a manufacturing machine comprising an apparatus according to the invention, the apparatus being configured to fetch a loose end of a sheet of material upstream of a crimp stage encompassing two rollers between which the sheet of material is to be treated;

(3) FIG. 2 shows a suction device of the apparatus in FIG. 1 according to the invention;

(4) FIG. 3 shows a schematic side view of the suction device in FIG. 2;

(5) FIG. 4 shows a schematic side view of the suction device in FIG. 2 in contact with a detached portion of a sheet of material;

(6) FIG. 5 shows a schematic side view of an embodiment of the apparatus according to the invention with the suction device in a first position;

(7) FIG. 6 shows a schematic side view of an embodiment of the apparatus according to the invention with the suction device in a second position; and

(8) FIG. 7 shows a flowchart of the inventive method.

(9) With initial reference to FIG. 1, the figure shows in a simplified way an isometric view of a part of a manufacturing machine 1 for manufacturing of aerosol-generating articles, using material 40 that is in sheet format delivered in bobbins 152. Such material could be for instance TCL (Tobacco Cast Leaf), comprising dried tobacco leaves which are cut in foils which are wound up into bobbins 152 for storage and transport. The material such as TCL may be both sticky and fragile which makes handling of the material difficult to unwind. Each bobbin 152 defines an outer or external surface 154 and a loose end (not visible) of the sheet of material 40 wound in the bobbin.

(10) The manufacturing machine 1 comprises an apparatus 100 according to the invention, the apparatus 100 being configured to fetch a loose end of the sheet of material 40 which is wound up in the bobbin 152. For fetching the loose end of the sheet 40 the apparatus 100 comprises a suction device 110 which is described in detail in the following figures.

(11) As an example, the bobbin 152 is arranged upstream of a crimp stage 10 of the manufacturing machine 1. During the manufacturing process, a specific machine unwinds these bobbins 152, one at a time, so as to use the sheet of material 40 for instance to create part of the aerosol-generating articles. The sheet of material unwound from the bobbin is used in the crimp stage 10.

(12) The crimp stage 10 includes two crimping rollers 11, 21 between which the sheet of material 40 is to be treated. The transport direction 30 of the sheet 40 is indicated with an arrow pointing to left forward in the figure.

(13) The first and second facing crimping roller 11, 21 define a first and second rotation axis 17, 27, respectively. The surfaces 12, 22 of the rollers 11, 21 are provided with ridge- and trough pattern 16, 26, which are indicated in a simplified manner by two circumferential lines on the surface of each roller 11, 21. The ridge- and trough pattern 16, 26 of the rollers 11, 21 generate corrugations in the sheet of material 40 when the sheet of material 40 is moved in transport direction 30 between the two crimp rollers 11, 21 of the crimp stage 10.

(14) The apparatus 100 for unwinding the bobbin 152 comprises a rotatable bobbin holder 150 and the suction device 110 arranged at an articulated arm (visible in FIGS. 5-6). The articulated arm is provided for adapting the position of the suction device 110 with respect to the external surface 154 of the bobbin 152. The rotatable bobbin holder 150 is adapted to be inserted in the bobbin 152. The bobbin holder 150 then rotates and unwinds the bobbin while the sheet of material 40 coming from the bobbin 152 is dragged by specific rollers of the crimp stage 10. During manufacturing, the bobbin is unwound at a high speed so that the sheet of material 40 coming from the bobbin 152 can be processed with speeds usually between about 200 and about 400 meters per minute.

(15) The apparatus 100 further comprises a speed sensor 192, a diameter sensor 194 and a presence sensor 196.

(16) The speed sensor 192 is coupled to the rotatable bobbin holder 150 and adapted to determine an angular speed of the bobbin holder 150. The angular speed of the rotatable bobbin holder 150 can be synchronized with a required transport speed of the sheet of material 40.

(17) The diameter sensor 194 is arranged close to the bobbin 152 and adapted to determine a diameter of the bobbin 152. The diameter of the bobbin 152 helps to know, for instance, when the bobbin 152 is close to be depleted and has to be replaced. Further, the suction device 110 can be positioned depending on a current diameter of the bobbin 152.

(18) A presence sensor 196 is positioned at a contact surface 124 of the suction device 110, better detailed below and not visible in FIG. 1, and adapted to determine the presence of a sheet portion on the contact surface of the suction device 110. The presence sensor 196 determines if the sheet of material 40 is correctly dragged by the suction device 110. Preferably, the presence sensor 196 is an optical sensor. For instance, the optical sensor may comprise a laser emitting diode coupled with a photosensitive sensor, and is pointing where the sheet of material 40 should be positioned when correctly fetched by the suction device 110. In case the sheet of material 40 is indeed in the correct position, the sheet of material 40 will reflect the light of the laser which will be captured by the photosensitive sensor. In such embodiment the optical sensor is positioned so as to point on the sheet of material 40 when the sheet of material 40 is passing a specific portion of the suction device 110.

(19) Preferably, the specific portion is in an area of a guiding means 160 of the suction device 110 (also not visible in FIG. 1 and better detailed below), where the sheet of material 40, when correctly positioned, will pass between the guiding means 160 and a contact surface of the suction device 110. To avoid catching a reflection of the laser from other parts that could be misinterpreted as the presence of the sheet of material 40 even when the sheet of material 40 is not present, there is an opening in the guiding means 160 in regard to the optical sensor. Thus, in case the sheet of material 40 is not in position, the light emitted by the laser will go through the opening and will not be reflected by the guiding means. The speed sensor 192, the diameter sensor 194 and the presence sensor 196 are electrically connected to a control unit 190 so as to send to the control unit 190 signals relative to the angular speed of the rotatable bobbin holder 150, the diameter of the bobbin 152 and the presence of sheet portion of the sheet of material 40 coming from the bobbin 152, respectively.

(20) The control unit 190 is adapted to command a movement of the articulated arm (not shown in this figure). The control unit 190 is adapted to regulate a speed of the surface of the suction device 110 depending on the angular speed of the bobbin holder 152.

(21) The handling of the bobbin 152, and specifically the mounting of a new bobbin 152, implies at one stage to fetch the loose end part of the sheet of material 40 of the new bobbin 152 and connect it to a specific part of the manufacturing machine which can then make a splice with the sheet of material coming from the previous bobbin which may then be cut and removed from the manufacturing machine. Favourably, the inventive apparatus 100 allows for a safe fetching of the loose end part of the sheet of material 40 of the new bobbin 152.

(22) FIG. 2 shows an embodiment of the suction device 110 of the apparatus 100 in FIG. 1 according to the invention. The suction device 110 includes the contact surface 124 having a first portion 130 capable of exerting a first suction power and a second portion 132 capable of exerting a second suction power different from zero. The first suction power is higher than the second suction power. The suction device 110 is attached to an articulated arm (not shown in this figure). Preferably, the contact surface 124 of the section device 110 is movable. This allows moving the sheet of material in a transport direction when it is in contact with the suction device 110.

(23) A width of the contact surface 124 of the suction device 110 at the first portion 130 is wider than a width of the surface 124 of the suction device 110 at the second portion 132.

(24) The suction device 110 includes at least one conveyor belt. Preferably, the suction device 110 includes three conveyor belts 140, 142, 144, positioned one adjacent to the others, so as to define a central conveyor belt 140 and two lateral conveyor belts 142, 144. The central conveyor belt 140 is longer than the lateral conveyor belts 142, 144. The first portion of the surface 124 of the suction device 110 includes a surface portion of the central conveyor belt 140 and of the two lateral conveyor belts 142, 144 and the second portion 132 includes a surface portion of the central conveyor belt 140. Openings 134 (only two are labelled with a reference numeral as an example) in the conveyor belts 140, 142, 144. The suction device 110 comprises an air system (not shown) allowing the outside air to be sucked by the air system so that it can create a suction effect to an outside material in contact with the suction device 110.

(25) The relative positioning of the conveyor belts 142, 144 is such that their surfaces that will be in contact with the sheet of material 40 are coplanar. Further, the conveyor belts 140, 142, 144 have a common end from which they extend. From this common end, the loose end of the bobbin 152 will be fetched by the suction device 110. In order to easily coordinate the speed of the conveyor belts 140, 142, 144, the conveyor belts 140, 142, 144 preferably share the same drive in their drive pulleys 121 with a common axis 127. Conveyor belts 140, 142, 144 may include additional pulleys 122, 123. The other pulleys 122, 123 may be idler pulleys with axes 128, 129.

(26) Using multiple conveyor belts 140, 142, 144, in particular three conveyor belts 140, 142, 144, allows distributing the suction effect on a relatively large surface which will both create an overall strong suction strength while at the same time preventing damaging the sheet of material 40.

(27) In this perspective, the size or diameter of openings 134 in the conveyor belts 140, 142, 144 may be adjusted according to the material that will be treated. For a fragile material, the openings 134 may be bigger than for a stronger material, as the pressure/suction is related to the surface of the openings 134. For instance, a large opening will create the same suction effect as smaller openings having a third of the diameter but distributed on a surface nine time larger.

(28) FIGS. 3 and 4 show schematic side views of the suction device 110 of FIG. 2, respectively without and with a portion of the sheet of material 40 being detached and pulled away from the bobbin 152.

(29) In the lateral views, the contact surface 124 including the first portion 130 exerting the first suction power and the second portion 132 exerting the second suction power different from zero, are visible. The contact surface 124 of the suction device 110 faces the sheet of material 40 when a sheet of material 40 is present, as depicted in FIG. 4. Further, guiding means 60 are visible, which have been mentioned in connection to presence sensor 196.

(30) The guiding means 160 is positioned substantially parallel to the contact surface 124 of the suction device 110 and overlaps a part of the second portion 132. The guiding means 160 is adapted to guide an end portion of the sheet of material 40 between the surface 124 of the suction device 110 and the guiding means 160. The guiding means 160 may have a skate-like shape. The guiding means 160 helps to separate the sheet of material from the bobbin 152 (FIG. 1) when unwinding it. The sheet of material can slide upon the guiding means 160.

(31) The guiding means 160 has roughly a flat surface, with the plane of the surface parallel to the contact surface 124 of the conveyor belts. The guiding means 160 is located at the end of the suction device 110 which is opposite to where the suction device fetches the sheet of material 40 from the bobbin 152. The guiding means 160 has a specific tip shape where the incoming sheet of material 40 arrives. This tip is rounded (or angled) toward the sheet of material 40 and planar on the other side toward the bobbin 152, so that the round side helps gently pulling the sheet of material 40 from the bobbin 152 without presenting acute angle that could cut the sheet of material 40, while the flat part allows the round side to get, if needed, as close as possible to the bobbin 152 so the sheet of material 40 gets early separated with a slight and increasing angle.

(32) When the suction device 110 makes contact with the sheet of material 40, the contact surface 124 of the suction device 110 is arranged tangentially to the external surface 154 of the bobbin 152 (see for example FIG. 4 where the sheet 40 is depicted).

(33) Once the loose end of the sheet of material is grabbed, it has to be separated from the bobbin 152. This is done by the coordinate dragging action of the conveyor belts 140, 142, 144. The surfaces of the conveyor belts 140, 142, 144 are aligned so that they are tangentially positioned to the external surface 154 of the bobbin 152, and which are moving at the same speed as the external surface 154 of the bobbin 152. The conveyor belts 140, 142, 144 preferably work in a coordinated manner on this area of the sheet of material 40.

(34) Once the loose end has been detached from the bobbin 152, less strength needs to be applied to hold the sheet of material 40 and to drag it up to the end of the suction device 110. Preferably, only one conveyor belt 140 is present in the second portion 132 of the suction device 110. However, to keep enough suction power when going from the first portion 130 of the suction device 110 in transport direction of the sheet of material 40, the width of the central conveyor belt 140 may be larger than the other conveyor belts 142, 144, for instance ⅓ larger and so having ⅓ more holes for air suction, than the two shorter conveyor belts 142, 144.

(35) The indicated structure of three conveyor belts 140, 142, 144 separates the area of the suction device which is intended for making contact with the sheet of material 40 into two portions for the suction device 110, one portion with a strong suction power (the area with the three conveyor belts) and one with less suction power (the area with one conveyor belt 140), giving a lot of flexibility in the use of the suction device 110.

(36) The apparatus 100 may also comprise a cylinder 126 (see FIG. 4) may be provided at the contact surface 124 of the suction device 110 with the cylinder axis perpendicular to the direction of the sheet of material 40 and parallel to the contact surface 124. This cylinder 126 can be moved, for instance using a rail, a chain and a drive, along the transport direction of the contact surface 124. The sheet of material 40 goes between the cylinder 126 and the contact surface 124 of the suction device 110. By moving the cylinder 126 toward the end of the suction device 110 close to the bobbin 152, it is possible to redirect the dragging force applied to the sheet of material 40 by the suction device 110 so that the force acts quite radial to the bobbin 152, helping to detach the sheet of material 40 from the bobbin 152 and, thus, supporting unwinding the bobbin 152.

(37) FIGS. 5 and 6 show schematic side views of an embodiment of the apparatus 100 according to the invention with the suction device 110 in a first position and a second position, respectively.

(38) The apparatus 100 further includes an articulated arm 180 and a rotatable arm 188 connected with the suction device 110 in order to move the same in substantially any position of the bobbin. The articulated arm 180 preferably has two points of articulation 182, 184, one roughly in the middle of the longitudinal elongation of the suction device 110, in particular of the central conveyor belt 140, and one between two arm segments 181, 183. The first arm segment 181 is attached to the suction device 110 and pivotable about the first point of articulation 182. The other arm segment 183 is a motorized component that is attached to a pivot joint 119 having a pivot axis 118 close to the rotatable bobbin holder 150 (FIG. 1).

(39) The rotatable arm 188 is pivotable around the same axis 117 as the rotatable bobbin holder 150 (FIG. 1) and links the rotatable bobbin holder 150 (FIG. 1) and the distal end of the suction device 110. The rotatable arm 188 is connected to the suction device 110 at a pivot joint 185 arranged at the end of the suction device 110 which is distal from the bobbin 152 (FIG. 1).

(40) Such structure, using just two motorized rotational parts the angles of which can be adjusted independently from one another, allows the accurate positioning of the suction device 110 so that the contact surface 124 of the suction device 110 in contact with the sheet of material 40 coming out of the bobbin 152 can move toward the bobbin 150 while keeping the same tangential angle with reference to the bobbin 152.

(41) In FIG. 6 the suction device 110 has been moved downwards compared to the position in FIG. 5, which is indicated by a bold arrow in FIG. 6, by a movement of the articulated arm 180 and the rotatable arm 188. The rotatable arm 188 has the same axis 117 as the rotatable bobbin holder 150 and the articulated arm 180 has an axis 118 next to the rotatable bobbin holder 150, while conserving the same alignment of the contact surface 124 regarding to the rotatable bobbin holder 150.

(42) According to the invention, it is possible to position the suction device 110 in regard to the bobbin 152 and to make it following in real time the external surface 154 of the bobbin 152 (see FIG. 1) while the bobbin 152 is unwound, keeping the same planar alignment. The suction device 110, once properly positioned, can fetch and drag the loose end of the bobbin 152.

(43) The control unit 190 shown only in FIG. 1 is adapted to command a movement of the articulated arm 180 so that the first portion 130 of the contact surface 124 of the suction device 110 contacts the bobbin 152. The control unit 190 (FIG. 1) is adapted to regulate a speed of the surface 124 of the suction device 110 depending on the angular speed of the rotatable bobbin holder 150.

(44) To work properly, the control unit 190 preferably receives in real time information about the current diameter of the bobbin 152, so as to be able to position correctly the suction device 110 regarding the external surface 154 of the bobbin 152, the angular speed of the rotatable bobbin holder 150 and current diameter of the bobbin 152 so as to move the contact surface 124 of the suction device 110 at the same speed than the outgoing sheet of material 40 so as to efficiently drag it. The angular speed of the rotatable bobbin holder 150 and the current diameter of the bobbin 152 allow evaluating the speed of the outgoing sheet of material 40 (the angular speed multiplied by the circumference of the bobbin 152).

(45) An alternative way to do it is to adjust to the conveyor belts 140, 142, 144 the speed of the dragging rollers 11, 21 (FIG. 1) of the other part of the manufacturing machine, for instance the wished manufacturing speed of the sheet of material 40.

(46) FIG. 7 illustrates a flowchart of the inventive method to fetch an end portion of the sheet of material 40 wound in the bobbin 152.

(47) In step 200 the external surface 154 of the bobbin is contacted with the suction device 110. Step 200 may include contacting the external surface tangentially to the external surface.

(48) In step 202 the contacted surface of the sheet is sucked towards the contact surface 124 of the suction device with a first suction power so as to detach a sheet portion from the bobbin.

(49) After detachment of the sheet from the bobbin, in step 204 the sheet portion which has been sucked with a first suction power is sucked towards the contact surface 124 of the suction device with a second suction power, wherein the second suction power is lower than the first suction power. Optionally, step 204 may include guiding the detached sheet portion within a passage formed in the suction device. Further optionally, step 204 may include detecting whether a portion of the sheet has been detached from the bobbin.