Elastic contact element for wrapping a sheet around a group of segments

Abstract

A wrapping device 1 for wrapping a sheet 3 around a group 5 of segments comprises a wrapping conveyor 7 and a contact element 25. The wrapping conveyor 7 comprises a conveyor surface 9 for receiving the group 5 of segments. The contact element 25 provides a counter surface 31. The counter surface 31 is arranged at a distance to the conveyor surface 9 of the wrapping conveyor 7. The counter surface 31 faces the conveyor surface 9 of the wrapping conveyor 7. The counter surface 31 is configured to engage the group 5 of segments and the sheet 3 when the group 5 of segments is moved along the counter surface 31 by the wrapping conveyor 7 to cause rotation of the group 5 of segments to wrap the group 5 of segments with the sheet 3. At least a first portion 41 of the contact element 25 comprising at least a first part 35 of the counter surface 31 is formed by a first material being an elastic material having a shore hardness between 30 A and 70 A.

Claims

1. A wrapping device for wrapping a sheet around a group of segments, the wrapping device comprising: a wrapping conveyor comprising a conveyor surface for receiving the group of segments; and a contact element providing a counter surface, wherein the counter surface is arranged at a distance to the conveyor surface of the wrapping conveyor, wherein the counter surface faces the conveyor surface of the wrapping conveyor, and wherein the counter surface is configured to engage the group of segments and the sheet when the group of segments is moved along the counter surface by the wrapping conveyor to cause rotation of the group of segments to wrap the group of segments with the sheet, wherein at least a first portion of the contact element comprises at least a first part of the counter surface and is formed by a first material being an elastic material having a shore hardness between 30 A and 70 A, and wherein a second portion of the contact element comprises a second part of the counter surface and has different elastic properties than the first portion of the contact element, wherein the first portion of the contact element and the second portion of the contact element are arranged to contact the group of segments at different positions.

2. The wrapping device according to claim 1, wherein the first material has a shore hardness between 40 A and 50 A.

3. The wrapping device according to claim 1, wherein the first material has a Young modulus of elasticity of less than 20 MPa, or of less than 15 MPa, or of less than 10 MPa, or of less than 5 MPa, or of less than 3 MPa, or of less than 2.5 MPa.

4. The wrapping device according to claim 1, wherein the first portion of the contact element has a thickness of at least 1 mm, or at least 2 mm, or at least 4 mm, or at least 6 mm, or at least 8 mm, or at least 10 mm.

5. The wrapping device according to claim 1, wherein the first portion of the contact element and the second portion of the contact element have different thicknesses.

6. The wrapping device according to claim 1, wherein the second portion of the contact element is formed by a second material having a shore hardness of at most 100 A, or of at most 90 A.

7. The wrapping device according to claim 1, wherein the conveyor surface defines grooves for receiving the group of segments, the grooves being oriented perpendicular to a conveying direction of the group of segments.

8. The wrapping device according to claim 1, wherein the second portion of the contact element is formed by a second material having a higher shore hardness than the first material.

9. The wrapping device according to claim 1, wherein the wrapping conveyor comprises a main body coated with a layer of elastic material.

10. A system for producing a smoking article, the system comprising the wrapping device of claim 1; the sheet; and the group of segments, wherein the group of segments comprises segments of a smoking article.

11. The system according to claim 10, wherein the segments of the smoking article comprise one or more of a segment comprising a heat source for a smoking article, and a segment comprising tobacco material, and a segment comprising a filter for a smoking article, and a segment comprising a mouthpiece for a smoking article.

Description

(1) In the following, the invention will be further described by describing embodiments with reference to the figures.

(2) FIG. 1 shows a schematic side view of a wrapping device according to an embodiment.

(3) FIG. 2 shows a top view onto the conveying surface of the wrapping conveyor of the wrapping device according to the embodiment showing two grooves being occupied by groups of segments and one empty groove.

(4) FIG. 3 shows a schematic view onto the counter surface provided by the contact element of the wrapping device according to the embodiment.

(5) FIG. 4 schematically shows a sheet being wrapped around a group of segments between the conveyor surface and the counter surface in the wrapping device according to the embodiment.

(6) FIG. 1 shows a schematic side view of a wrapping device 1 according to an embodiment. The wrapping device 1 is configured for wrapping a sheet 3 around a group 5 of segments. The segments of the group 5 of segments may be cylindrically shaped or rod shaped, for example. The segments of the group 5 of segments may be longitudinally aligned with each other in an end-to-end relationship, when wrapped with the sheet 3. The wrapping device 1 comprises a wrapping conveyor 7 for receiving groups 5 of segments. In the illustrated embodiment, the wrapping conveyor 7 comprises a rotatable roller defining a conveyor surface 9 for receiving the groups 5 of segments on its outer circumferential surface.

(7) FIG. 2 shows a plan view onto the conveyor surface 9 of the wrapping conveyor 7. The conveyor surface 9 defines grooves 11 extending in parallel to an axis of rotation 13 (see FIG. 1) of the wrapping conveyor 7. Each of the grooves 11 is configured to receive a group 5 of segments to be wrapped with a sheet 3. In FIG. 2, the left two grooves 11 are occupied by a group 5 of segments, respectively. The right groove 11 is empty. In the illustrated embodiment, the groups 5 of segments comprise segments of a smoking article. In a groove 11, the segments of a group 5 of segments are arranged one behind the other in an end-to-end relationship.

(8) According to the embodiment illustrated in FIG. 2, a group 5 of segments comprises a cap segment 15 comprising a removable cap for a smoking article, a heat source segment 17 comprising a heat source for a smoking article, a tobacco material segment 19 comprising tobacco material, and a diffuser segment 21 comprising a diffuser for a smoking article. The group 5 of segments might, additionally or as an alternative to one of the illustrated segments, comprise a filter segment comprising a filter for a smoking article. The group 5 of segments might, additionally or as an alternative to one of the illustrated segments, comprise a mouthpiece segment comprising a mouthpiece of a smoking article. By wrapping the sheet 3 around the group 5 of segments, the segments of the group 5 of segments will be combined. The group 5 of segments may comprise all required segments of a smoking article. Alternatively, the group 5 of segments may comprise only a subset of all the segments required for production of the smoking article and additional segments may be added in subsequent steps. In the illustrated embodiment, a part of a smoking article is formed by wrapping the sheet 3 around the cap segment 15, the heat source segment 17, the tobacco segment 19 and the diffuser segment 21. Later, a filter segment and a mouthpiece segment will be added in another wrapping step. It would, however, also be conceivable to include the filter segment and the mouthpiece segment in the first wrapping step.

(9) The sheets 3 to be wrapped around the groups 5 of segments are also received on the conveyor surface 9 of the wrapping conveyor 7. A front edge of the sheet 3 may reach into the groove 11 and lie below the group 5 of segments received in the groove 11. Preferably, the front edge of the sheet 3 is glued to the group 5 of segments to establish an initial connection between the group 5 of segments and the sheet 3. The sheets 3 may be cut from a supply roll, provided with glue strips at the front edge and at the rear edge and be supplied to the conveyor surface 9 of the supply roll 7 so that the front edges of the sheets 3 reach into grooves 11 of the conveyor surface 9. Subsequently, the groups 5 of segments may be deposited in the grooves 11 of the conveyor surface 9 to come into contact with the glue strip at the front edge of the sheet 3. Alternatively, the sheets 3 and the groups 5 segments may be glued together first and then be supplied to the conveyor surface 9 as a unit. After the sheet 3 has been wrapped around the group 5 of segments, as will be described later, the sheet will be fixed by the glue strip at the rear edge of the sheet 3.

(10) To ensure adhesion between the sheets 3 and the conveyor surface 9 during rotation of the wrapping conveyor 7, suction holes 23 are provided in the conveyor surface 9. The sheets 3 are held at the conveyor surface 9 by under-pressure applied to the suction holes 23. There may be suction holes 23 provided in the grooves 11 of the conveyor surface 9 and between the grooves 11 of the conveyor surface 9.

(11) The wrapping device 1 further comprises a contact element 25. The contact element 25 comprises a main body 27 and a contact body 29 attached thereto. The contact body 29 provides a counter surface 31. The counter surface 31 is arranged at a distance to the conveyor surface 9 of the wrapping conveyor 7. The counter surface 31 extends essentially parallel to the conveyor surface 9 of the wrapping conveyor 7 and faces the conveyor surface 9 of the wrapping conveyor 7.

(12) When a group 5 of segments is conveyed by rotation of the wrapping conveyor 7 between the conveyor surface 9 of the wrapping conveyor 7 and the counter surface 31 of the contact element 25, the group 5 of segments engages the counter surface 31 of the contact element 25. When the group 5 of segments is moved along the counter surface 31 of the contact element 25 by continued rotation of the wrapping conveyor 7, friction between the counter surface 31 of the contact element 25 and the group 5 of segments causes the group 5 of segments to rotate about its own axis, thereby wrapping the sheet 3 around the group 5 of segments. When the group 5 of segments leaves the gap between the wrapping conveyor 7 and the contact element 25, the sheet 3 has been completely wrapped around group 5 of segments. Downstream of the contact element 25, the group 5 of segments wrapped with the sheet 3 may be transferred from the wrapping conveyor 7 to another conveyor 27 for further processing.

(13) The contact element 25 is provided with a heater 33 for heating the contact element 25. This may contribute to drying the group 5 of segments and to curing the glue strips.

(14) FIG. 3 shows a plan view onto the counter surface 31 of the contact element 25. A left-right direction in FIG. 3 corresponds to the conveying direction along which the groups 5 of segments are moved along the counter surface 31. The up-down direction in FIG. 3 corresponds to a direction along which the segments of the group 5 of segments are arranged one behind the other. The up-down direction in FIG. 3 is parallel to the rotations axis 13 of the wrapping conveyor 7.

(15) In the illustrated embodiment, the counter surface 31 of the contact element 25 is divided into three parts. A first part 35 of the counter surface 31 is arranged to come in contact with the cap segment 15 and the heat source segment 17 of the group 5 of segments. A second part 37 of the contact surface 31 is arranged to come in contact with the tobacco segment 19 of the group 5 of segments. A third part 39 of the counter surface 31 is arranged to come in contact with the diffuser segment 21 of the group 5 of segments. The first part 35 of the counter surface 31 is defined by a first portion 41 of the contact element 25. The second part 37 of the counter surface 31 is defined by a second portion 43 of the contact element 25. The third part 39 of the counter surface 31 is defined by a third portion 45 of the contact element 25. The first portion 41, the second portion 43, and the third portion 45 of the contact element 25 are portions of the contact body 29 of the contact element 25.

(16) The first portion 41 of the contact element 25 is formed by a first material. The first material is a material having a shore hardness between 30 A and 70 A. According to embodiments, the first material may have a shore hardness between 30 A and 60 A, or a shore hardness between 30 A and 50 A, or a shore hardness between 40 A and 50 A. The first material may have a Young modulus of elasticity of less than 20 MPa, or of less than 15 MPa, or of less than 10 MPa, or of less than 5 MPa, or of less than 3 MPa, or of less than 2.5 MPa. The first portion of the contact element may have as thickness of at least 1 mm, or of at least 2 mm, or of at least 4 mm, or of at least 6 mm, or of at least 8 mm, or of at least 10 mm.

(17) FIG. 4 shows a cross-sectional view illustrating engagement between the heat source segment 17 of a group 5 of segments and the first part 35 of the counter surface 31 during wrapping of the sheet 3 around the group 5 of segments. Due to the material properties of the first portion 41 of the contact element 25, the heat source segment 17 may deform the first part 35 of the counter surface 31 away from the conveyor surface 9. The heat source segment 17 may immerse into the first portion 41 of the contact element 25. This may protect the heat source segment 17 from being damaged due to too much pressure exerted onto the heat source segment 17 upon wrapping between the conveyor surface 9 and the counter surface 31.

(18) The second portion 43 of the contact element 25 may have different elastic properties than the first portion 41 of the contact element 25. The second portion 43 of the contact element 25 may be formed by a second material having a higher shore hardness than the first material.

(19) In particular, a shore hardness of the second material may be higher than the shore hardness of the first material, but not higher than 90 A or not higher than 100 A. The second part 37 of the counter surface 31 comes in contact with the tobacco segment 19 during wrapping of the sheet 3 around the group 5 of segments. The tobacco segment 19 may in itself be compressible. It may be advantageous, if the tobacco segment 19 is compressed between the conveyor surface 9 and the counter surface 31. There may be no or substantially no deformation of the second part 37 of the counter surface 31 by the tobacco segment 19 upon wrapping of the group 5 of segments between the conveyor surface 9 and the counter surface 31.

(20) The diffuser segment 21 may be essentially non-compressible and may be susceptible to damage due to high pressure exerted on the diffuser segment 21. The third portion 45 of the contact element 25 may have elastic properties that are similar to the elastic properties of the first portion 41 of the contact element 25. In particular, the third portion 45 may also be formed by the first material. The diffuser segment 21 may be configured to elastically deform the third part 39 of the counter surface 31 away from the conveyor surface 9 upon wrapping the sheet 3 around the group 5 of segments between the conveyor surface 9 and the counter surface 31.

(21) According to an embodiment, the first portion 41 of the contact element 25, the second portion 43 of the contact element 25, and the third portion 45 of the contact element 25 may have the same thickness. Alternatively, at least two of the first portion 41 of the contact element 25, the second portion 43 of the contact element 25, and the third portion 45 of the contact element 25 may have different thicknesses. For example, the thickness of the first portion 41 of the contact element 25 may be higher than the thickness of the second portion 43 of the contact element 25. The first portion 41 of the contact element 25 may have a higher thickness to allow for deformation of the first part 35 of the counter surface 31 away from the conveyor surface 9. The second portion 43 of the contact element 25 need not be deformed and may therefore have a lower thickness.

(22) According to the embodiment shown in FIG. 4, a main body 47 of the wrapping conveyor 7 may be coated with a layer 49 of elastic material. The layer 49 of elastic material may be formed from a third material. The third material may, for example, be identical to the first material or the second material.