AEROSOL-GENERATING SYSTEM AND AEROSOL-GENERATING ARTICLE COMPRISING AN AEROSOL-FORMING SUBSTRATE

Abstract

An aerosol-generating system is provided, including an aerosol-generating article and an aerosol-generating device, the article having an upstream end and a downstream end, and defines a longitudinal direction and includes an upstream segment and a downstream segment, the upstream segment includes an aerosol-forming substrate having a substrate outer surface with a substrate outer diameter, the downstream segment having a downstream segment outer diameter greater than the substrate outer diameter, the device including a device cavity inner surface having a device cavity inner diameter, the device cavity being configured to receive at least the aerosol-forming substrate, the device further including at least one heating element, and when the aerosol-forming substrate is received in the device cavity, an airflow passage is defined between the substrate outer surface and the device cavity inner surface.

Claims

1.-14. (canceled)

15. An aerosol-generating system, comprising: an aerosol-generating article having an upstream end and a downstream end, the aerosol-generating article defining a longitudinal direction between the upstream end and the downstream end, the aerosol-generating article comprising: an upstream segment disposed at the upstream end of the aerosol-generating article, the upstream segment comprising an aerosol-forming substrate, the aerosol-forming substrate comprising a substrate outer surface having a substrate outer diameter, and a downstream segment disposed at the downstream end of the aerosol-generating article, the downstream segment having a downstream segment outer diameter, the downstream segment outer diameter being greater than the substrate outer diameter; and an aerosol-generating device comprising: a device cavity comprising a device cavity inner surface having a device cavity inner diameter, the device cavity being configured to receive at least the aerosol-forming substrate of the aerosol-generating article, and at least one heating element configured to heat the aerosol-forming substrate when the aerosol-forming substrate is received in the device cavity, wherein, when the aerosol-forming substrate of the aerosol-generating article is received in the device cavity, an airflow passage is defined between the substrate outer surface and the device cavity inner surface, the airflow passage extending in the longitudinal direction along a length of the aerosol-forming substrate.

16. The aerosol-generating system of claim 15, wherein the aerosol-forming substrate further comprises a substrate inner surface having a substrate inner diameter, the substrate inner surface delimiting an inner cavity extending in the longitudinal direction within the aerosol-forming substrate.

17. The aerosol-generating system of claim 16, wherein the substrate inner diameter is between about 60% and about 90% of the substrate outer diameter.

18. The aerosol-generating system of claim 16, wherein a layer of thermally conductive material is disposed on the substrate inner surface.

19. The aerosol-generating system of claim 15, wherein the upstream segment and the downstream segment are arranged in coaxial alignment with a longitudinal axis of the aerosol-generating article.

20. The aerosol-generating system of claim 15, wherein the downstream segment comprises a filter.

21. The aerosol-generating system of claim 20, wherein the downstream segment further comprises at least one of a cooling element and a spacing element disposed between the aerosol-forming substrate and the filter.

22. The aerosol-generating system of claim 15, wherein the substrate outer diameter is between about 50% and about 98% of the downstream segment outer diameter.

23. The aerosol-generating system of claim 15, wherein the substrate outer surface has a transverse cross-section with a circular shape or an oval shape.

24. The aerosol-generating system of claim 15, wherein the aerosol-forming substrate further comprises tobacco cast leaf.

25. The aerosol-generating system of claim 15, wherein the aerosol-forming substrate has a substantially homogenous composition in the longitudinal direction.

26. The aerosol-generating system of claim 15, wherein the aerosol-forming substrate further comprises a first aerosol-forming substrate segment extending in the longitudinal direction, and a second aerosol-forming substrate segment adjacent the first aerosol-forming substrate segment in the longitudinal direction.

27. The aerosol-generating system of claim 15, wherein the device cavity defines the longitudinal direction between an upstream end of the device cavity and a downstream end of the device cavity, and wherein the at least one heating element comprises a first heating element and a second heating element spaced from each other in the longitudinal direction of the device cavity.

28. The aerosol-generating system of claim 15, wherein the downstream segment outer diameter of the aerosol-generating article is substantially the same as or greater than the device cavity inner diameter.

Description

[0153] These and other features and advantages of the invention will become more evident in the light of the following detailed description of preferred embodiments, given only by way of illustrative and non-limiting example, in reference to the attached figures:

[0154] FIG. 1 shows a schematic illustration of an aerosol-generating article according to a first embodiment of the invention.

[0155] FIG. 2 shows a schematic illustration of an aerosol-generating article according to a second embodiment of the invention.

[0156] FIG. 3 shows a schematic illustration of an aerosol-generating system according to a third embodiment of the invention, the aerosol-generating system comprising the aerosol-generating article of FIG. 1.

[0157] FIG. 4 shows a schematic illustration of an aerosol-generating system according to a fourth embodiment of the invention.

[0158] FIG. 5 shows a schematic illustration of an aerosol-generating system according to a fifth embodiment of the invention.

[0159] FIG. 6 shows a schematic illustration of an aerosol-generating system according to a sixth embodiment of the invention.

[0160] FIG. 7 shows a schematic illustration of an aerosol-generating device according to a seventh embodiment of the invention.

[0161] FIG. 8 shows a schematic illustration of an aerosol-generating system according to an eighth embodiment of the invention, comprising the aerosol-generating device of FIG. 7.

[0162] FIG. 1 shows an aerosol-generating article 10 comprising an upstream end 11 and a downstream end 12. The article 10 comprises an upstream segment, which comprises an aerosol-forming substrate 13, and a downstream segment 14, which in this embodiment consists of a filter 15. The filter 15 generally forms a cylindrical part of cellulose acetate, having an outer cylindrical surface with a downstream segment outer diameter D1. In this embodiment, the aerosol-forming substrate 13 generally forms a hollow, cylindrical tube of homogenised cast leaf tobacco. The tubular aerosol-forming substrate 13 has a substrate outer surface 17 having a substrate outer diameter D2 and a substrate inner surface 18 having a substrate inner diameter D3. The substrate inner surface 18 delimits an inner cavity 16 extending in the longitudinal direction within the aerosol-forming substrate 13.

[0163] The outer diameter D1 of the filter is greater than the outer diameter D2 of the substrate.

[0164] The thickness of the aerosol-forming substrate 13 is significantly reduced compared to the thickness of aerosol-forming substrates in articles having a consistent outer diameter along their length and articles in which the aerosol-forming substrate is not tubular. The reduced thickness of the aerosol-forming substrate 13 may enable heat applied to the substrate 13 to propagate rapidly through the thickness of the substrate. This may reduce the time required to raise the temperature of substrate 13. For example, this may reduce the time required to raise the temperature of the substrate 13 at regions of the substrate 13 that are furthest away from a heating element 31. The reduced thickness of the aerosol-forming substrate 13 of the aerosol-generating article 10 may improve efficiency of aerosol generation from the aerosol-generating article.

[0165] The aerosol-generating article 10 of FIG. 2 is similar to the article of the embodiment of FIG. 1 except in that the downstream segment 14 comprises a spacing element 19 and a filter 15. In this embodiment, a spacing element 19 is disposed between the filter 15 and the aerosol-forming substrate 13.

[0166] In this embodiment, the spacing element 19 is a support element. However, it will be appreciated that in other embodiments the article may be provided with a cooling element disposed between the filter 15 and the substrate 13 in addition to or instead of the support element.

[0167] FIG. 3 shows an aerosol-generating system 40 comprising the aerosol-generating article 10 of FIG. 1 and an aerosol generating device 30. The aerosol-generating device 30 comprises a heating element 31 which is configured to be inserted into the aerosol-forming substrate 13 when the aerosol-generating article is received in the device 30. In the embodiment of FIG. 3, the heating element 31 is received in the inner cavity 16 of the article 10, defined by the substrate inner surface 18.

[0168] The aerosol-generating device 30 comprises a device cavity 32 having a device cavity inner surface 33. The device cavity inner surface 33 has a device cavity inner diameter D4. In FIG. 3, the device cavity 32 receives the aerosol-forming substrate 13 of the article 10. When the aerosol-forming substrate 13 is received in the device cavity 32, an annular gap is formed between the substrate outer surface 17 and the device cavity inner surface 33, which provides an airflow passage 35 in the longitudinal direction along the length of the substrate 13, and circumscribing the substrate. The width of the airflow passage 35 is the difference between the chamber inner diameter D4 and the substrate outer diameter D2. The airflow passage 35 is external to the aerosol-forming substrate 13.

[0169] When the aerosol-generating system 40 is in use, as depicted in FIG. 3, power is provided to the heating element 31 to heat the aerosol-forming substrate 13 to a temperature at which volatile compounds are released from the substrate 13. A user drawing on the downstream segment 14, such as on the filter 15, of the article 10 causes air to be drawn into the airflow passage 35 though air inlets 36 at a distal end of the device cavity 32, along the airflow passage 35 in the longitudinal direction of the article 10, and out of the device cavity 32 through the downstream segment 14, such as through the filter 15. Volatile compounds released from the heated aerosol-forming substrate 13 evolve into the airflow passage 35, as is schematically represented by curved arrows in FIG. 3, and cool to form an aerosol that can be inhaled by a user. The aerosol is entrained in the air being drawn through the airflow passage 35 and flows out of the device cavity 32 through the filter 15 of the article 10 towards the downstream end 12, as indicated by arrow A1.

[0170] In the embodiment of FIG. 3, the downstream segment outer diameter D1 is the same as the device cavity inner diameter D4. Therefore, the airflow passage is delimited at its downstream edge by the downstream segment 14, which in this embodiment corresponds to the filter 15. Accordingly, aerosol that exits the airflow passage 35 is required to flow through the filter 15.

[0171] In the aerosol-generating system 40 of FIG. 4, the aerosol-generating article 10 differs from that of FIGS. 1 and 3 in that the aerosol-forming substrate 13 does not comprise an inner cavity; instead, the aerosol-forming substrate 13 is a solid, cylindrical plug of homogenised tobacco cast leaf. The aerosol-generating device 30 is identical to that of FIG. 3, except in that it comprises a heating element 31 that penetrates the aerosol-forming substrate 13 when the aerosol-forming substrate 13 is received in the device cavity 32. In some embodiments, the heating element is any of: a blade, a pin, a spike or any other shape configured to facilitate insertion of the heating element into the aerosol-forming substrate. For example, the heating element may have a tapered or pointed end. In the embodiment of FIG. 4, the heating element is a blade-shaped heating element.

[0172] In the aerosol-generating system 40 of FIG. 5, the aerosol-generating article 10 differs from that of FIGS. 1 and 3 in that the aerosol-generating article 10 comprises a downstream segment 14, which in this embodiment is a filter 15, having a downstream segment outer diameter D1 which is greater than the device cavity inner diameter D4. Such a downstream segment configuration may further ensure that the upstream edge of the filter 15 delimits the downstream edge of the airflow passage 35. In addition, a layer of thermally conductive material 23 is disposed on the substrate inner surface 18. The layer of thermally conductive material 23 substantially covers the substrate inner surface 18, circumscribing the inner cavity 16 and extending the entire length of the inner cavity 16. This may improve the distribution of heat from the heating element 31 to the substrate 13. The layer of thermally conductive material 23 may also create a physical separation between a heating element 31 received in the inner cavity 16 and the aerosol-forming substrate 13, which may reduce the risk of overheating the aerosol-forming substrate 13 in regions of the substrate 13 close to the heating element 31. The layer of thermally conductive material 23 may also increase the robustness of the tubular aerosol-forming substrate 13, which may have been diminished by the reduction in the thickness of the substrate 13 by the provision of the inner cavity 16.

[0173] The other features of the system 40 of FIG. 5 correspond to those of the system 40 of FIG. 3.

[0174] In the aerosol-generating system 40 of FIG. 6, the aerosol-generating device 30 comprises a first heating element 34 and a second heating element 38 spaced apart from one another in the longitudinal direction of the device cavity 32. The aerosol-generating article 10 comprises an aerosol-forming substrate 13 having two aerosol-forming substrate segments, a first aerosol-forming substrate segment 21 and a second aerosol-forming segment 22, arranged end-to-end in the longitudinal direction of the article. The first aerosol-forming substrate segment 21 comprises a first aerosol-forming substrate composition, and the second aerosol-forming substrate segment 22 comprises a second aerosol-forming substrate composition, different from the composition of the first longitudinal substrate segment 21.

[0175] The first heating element 34 is arranged to heat the first aerosol-forming substrate segment 21 and the second heating element 38 is arranged to heat the second aerosol-forming substrate segment 22 when the aerosol-forming substrate 13 is received in the device cavity 32. Accordingly, the aerosol-generating device 30 can be configured to individually heat each segment of the aerosol-forming substrate 13. Since heat can be selectively applied to the first substrate segment 21 and the second substrate segment 22, the segments 21, 22 can be sequentially heated by the aerosol-generating device 40. Each segment can also be heated according to the type of aerosol the user wishes to consume.

[0176] The aerosol-generating device 30 of FIG. 6 further comprises a sensor 37 disposed within the device cavity 32, on the device cavity inner surface 33, and within the airflow passage 35 when the aerosol-forming substrate 13 is received in the device cavity 32. The sensor 37 may provide the device and/or the user with relevant data such as the start of a puff, the duration of a puff, the temperature of the aerosol or the concentration of a certain component of the aerosol within the airflow passage 35.

[0177] FIG. 7 shows an aerosol-generating device 300 according to a further embodiment of the invention. The device 300 comprises a housing that is capable of forming a device cavity 305 for receiving an aerosol-forming substrate. The housing comprises a first housing part 301 and a second housing part 302, which are movable relative to one another. In this embodiment, the first and second housing parts 301, 302 are rotatable relative to each other, and the relative movement is represented by arrow R1 in FIG. 7. A hinge 307 rotatably attaches the first housing part 301 to the second housing part 302.

[0178] The first and second housing parts 301, 302 are rotatable between an open position and a closed position. In the closed position, the first and second housing parts 301, 302 are arranged to form a device cavity for receiving an aerosol-forming substrate 130. In the closed position, the formed device cavity may circumscribe the aerosol-forming substrate. In the open position, the first and second housing parts 301, 302 are arranged to permit an aerosol-forming substrate 130 to be received on and removed from the bodies 301, 302.

[0179] The first housing part 301 comprises a first cavity 303 and the second housing part 302 comprises a second cavity 304. In this embodiment, the first cavity 303 is a substantially hemi cylindrical cavity, and the second cavity 304 is a substantially hemi cylindrical cavity. In the closed position, the first cavity 303 and the second cavity 304 are aligned to form the device cavity 305 for receiving the aerosol-forming substrate 130. In this embodiment, the device cavity 305 circumscribes the aerosol-forming substrate 130 about a longitudinal direction X when the aerosol-forming substrate 130 is received in the device cavity 305. In other words, the device cavity 305 forms a tubular cavity that surrounds or encloses the aerosol-forming substrate 130, the tubular cavity having a length extending in the longitudinal direction X. The tubular cavity maybe closed at an end. In the open position, the first cavity 303 and the second cavity 304 are rotated to form an opening 306, through which aerosol-forming substrate 130 may be inserted into each of the first and second cavities 303, 304 in a direction different from the longitudinal direction X, as shown in FIG. 7. In this embodiment, the aerosol-forming substrate 130 may be inserted into either of the first and second cavities 303, 304 in a direction substantially perpendicular P1 to the longitudinal direction X.

[0180] The aerosol-generating device 300 comprises a plurality of internal heating elements 310. The internal heating elements 310 are configured for at least partially penetrating the aerosol-forming substrate. In this embodiment, the internal heating elements 310 are pin-shaped heating elements 310. The first housing part 301 comprises a plurality of the pin-shaped heating elements 310 extending into the first cavity 303, and the second housing part 302 comprises a plurality of the pin-shaped heating elements 310 extending into the second cavity 304. Specifically, in the illustrated embodiment, the device 300 comprises twelve heating elements 310, six heating elements 310 extending from the first housing part 301 into the first cavity 303 and six heating elements 310 extending from the second housing part 302 into the second cavity 304. The pin shaped heating elements 310 extend in a substantially transverse direction within the chamber 305. The pin shaped heating 310 elements are arranged to extend substantially parallel to each other and perpendicular to the longitudinal direction X of the cavity, when the first and second housing parts 301, 302 are in the closed position. Although pin-shaped heating elements are described and illustrated herein, it will be appreciated that any of a variety of shapes may be used. For example, the heating elements may have the shape of any one or combination of: a blade, a pin, a spike or any other shape configured to facilitate insertion of the heating element into the aerosol-forming substrate. For example, the heating element may have a tapered or pointed end. The heating elements in the first cavity 303 may be the same as each another or may vary. The heating elements in the second cavity 304 may be the same as each other, or may vary. The heating elements in the first cavity 303 may have the same shape or may have different shapes compared to the heating elements in the second cavity 304. Although twelve heating elements are described with reference to the illustrated embodiment, it will be appreciated that other numbers of heating elements may be used. Although the illustrated invention describes heating elements in both cavities 303, 304, it will be appreciated that in some embodiments, there may only be heating elements extending from one cavity.

[0181] Each of the first and second housing parts 301, 302 further comprises air inlets 360. The air inlets 360 are arranged at one end of the device cavity 305, and are arranged to enable ambient air to be drawn into the device cavity 305.

[0182] FIG. 8 shows a longitudinal cross-section of the aerosol-generating device 300 of FIG. 7 in the closed position, in use with an aerosol-generating article 100. The aerosol-generating article 100 shown in FIG. 8 is similar to that of FIG. 1. The article 100 comprises an aerosol-forming substrate 130 in an upstream segment. The article 100 comprises a downstream segment 140 which, in this embodiment, comprises a filter 150 directly downstream of the aerosol-forming substrate 130. In the embodiment shown in FIG. 8, the aerosol-forming substrate 130 has a cylindrical tubular shape, having an inner cavity 160. However, it will be appreciated that other aerosol-generating articles, and particularly non-tubular aerosol-generating articles, may be equally suitable for use with the aerosol-generating device of FIG. 7.

[0183] The device cavity 30 of the aerosol-generating device 300 extends in a longitudinal direction X, from an upstream end 308 of the device cavity to a downstream end 309 of the device cavity. In the closed position, the first cavity 303 and the second cavity 304 align to form the substantially cylindrical device cavity 305.

[0184] When the aerosol-forming substrate 130 is disposed in the first cavity 303 and the first and second housing parts 301, 302 are in the open position, the pin-shaped heating elements 310 of the first housing part 301 pierce the aerosol-forming substrate. When the first housing part 301 and the second housing part 302 are moved to the closed position, the aerosol-forming substrate is held in the cylindrical device cavity 305 and the pin-shaped heating elements 310 of the second housing part 302 also pierce the aerosol-forming substrate 130. As shown in FIG. 8, the pin shaped heating elements 310 are spaced apart from each other both in the longitudinal direction X and in a transverse direction. In this way, the pin shaped heating elements 310 are arranged to heat different portions of the aerosol-forming substrate 130. Advantageously, this should ensure that all of the aerosol-forming substrate 130 is heated to the desired temperature during use of the system 400.

[0185] In use, when a user draws on the filter 150 of the aerosol-generating article 100, air is drawn into the device cavity through air inlets 360 at the upstream end 308 of the device cavity. In this embodiment, the air inlets 360 are directed towards a central longitudinal axis of the device chamber. The air drawn into the device cavity from the air inlets 360 enters the inner cavity 160 of the aerosol-forming substrate 130, is drawn along the inner cavity 160 towards the filter 150, as indicated by arrow A10, and is released from the filter 150 at a downstream end 120 of the aerosol-generating article 100 where it is delivered to the user.

[0186] When power is provided to the plurality of heating elements 310, the plurality of heating elements 310 heat the aerosol-forming substrate 130 to a temperature at which volatile compounds are released from the substrate 130, which are released from the substrate 130 into the inner cavity 160 of the substrate 130 and cool to form an aerosol that can be inhaled by a user. The aerosol is entrained in the air drawn through the inner cavity 160 and is drawn out of the inner cavity 160 through the filter 150 and delivered to the user at the downstream end 120.