WO2024153754A1

WO2024153754A1 - Aerosol generating device configured to operate with a flat-shaped tobacco article

Info

Publication number: WO2024153754A1
Application number: PCT/EP2024/051179
Authority: WO
Inventors: Alec WRIGHT; Jaakko MCEVOY
Original assignee: JT International SA
Current assignee: JT International SA
Priority date: 2023-01-19
Filing date: 2024-01-18
Publication date: 2024-07-25
Anticipated expiration: 2025-07-19
Also published as: KR20250131821A; EP4651743A1

Abstract

An aerosol generating device configured to operate with a flat-shaped tobacco article and comprising a flat-shaped heating chamber extending along a device longitudinal axis (X2) between a proximal end configured to receive at least a tobacco portion of the flat- shaped tobacco article and a distal end opposite to the proximal end;. The distal end of the heating chamber comprises a distal wall (66) extending between two edges along a device transversal axis (Y2) substantially perpendicularly to the device longitudinal axis (X2); the distal wall (66) defining an air inlet portion configured to provide an airflow inside the heating chamber; the air inlet portion defining one or several inlet holes presenting a greater area at a central zone of the distal wall (66) than at peripheral zones of the distal wall (66), adjacent to its edges.

Description

Aerosol generating device configured to operate with a flat-shaped tobacco article

FIELD OF THE INVENTION

The present invention concerns an aerosol generating device configured to operate with a flat-shaped tobacco article. The aerosol generating device comprises a flat-shaped heating chamber.

Particularly, the flat-shaped tobacco article comprises for example a solid substrate able to form aerosol when being heated. Thus, such type of aerosol generating devices, also known as heat-not-burn devices, is adapted to heat, rather than burn, the substrate by conduction, convection and/or radiation, to generate aerosol for inhalation.

BACKGROUND OF THE INVENTION

The popularity and use of reduced-risk or modified-risk devices (also known as vaporisers) has grown rapidly in the past few years as an aid to assist habitual smokers wishing to quit smoking traditional tobacco products such as cigarettes, cigars, cigarillos, and rolling tobacco. Various devices and systems are available that heat or warm vaporizable substances as opposed to burning tobacco in conventional tobacco products.

A commonly available reduced-risk or modified-risk device is the heated substrate aerosol generation device or heat-not-burn device. Devices of this type generate aerosol or vapour by heating an aerosol substrate that typically comprises moist leaf tobacco or other suitable vaporizable material to a temperature typically in the range 150°C to 350°C. Heating an aerosol substrate, but not combusting or burning it, releases aerosol that comprises the components sought by the user but not the toxic and carcinogenic byproducts of combustion and burning. Furthermore, the aerosol produced by heating the tobacco or other vaporizable material does not typically comprise the burnt or bitter taste resulting from combustion and burning that can be unpleasant for the user and so the substrate does not therefore require the sugars and other additives that are typically added to such materials to make the smoke and/or vapour more palatable for the user. The aerosol generating devices with a flat-shaped heating chamber provide high user comfort due to easy handling of the flat-shaped form of the tobacco article configured to operate with the device. However, some known aerosol generating devices operating with flat-shaped tobacco articles can still be improved in terms of user comfort.

In particular, in some known devices, specific portions of the tobacco article may be submitted to a higher vapour extraction than other portions. As a consequence, vapour extraction may not always be optimal. In addition, for example peripheral regions of the tobacco article inserted in such known devices may be subject to cooling and condensation of vapour inside the heating chamber. This may also lead to less or suboptimal vapour extraction, and/or a poor appearance of a used tobacco article due to the condensation.

SUMMARY OF THE INVENTION

One of the aims of the invention is to provide an aerosol generating device configured to operate with a flat-shaped tobacco article, which allows improving user comfort, and in particular which allows improving vapor extraction in all areas of the flat-shaped tobacco article.

For this purpose, the invention relates to an aerosol generating device configured to operate with a flat-shaped tobacco article and comprising a flat-shaped heating chamber extending along a device longitudinal axis between a proximal end configured to receive at least a tobacco portion of the flat-shaped tobacco article and a distal end opposite to the proximal end. The distal end of the heating chamber comprises a distal wall extending between two edges along a device transversal axis substantially perpendicularly to the device longitudinal axis. The distal wall defines an air inlet portion configured to provide an airflow inside the heating chamber. The air inlet portion defines one or several inlet holes presenting a greater area at a central zone of the distal wall than at peripheral zones of the distal wall, adjacent to its edges.

Thanks to these features, an airflow inside the heating chamber is improved, in particular in all areas of the flat shaped tobacco article when being inserted into the heating chamber. Thus, user comfort is improved. For example, an airflow inside the heating chamber is increased at least in some parts of the heating chamber and/or is distributed evenly in the heating chamber. In particular, a pressure drop of an airflow traversing the air inlet portion is varied from the edges to the central zone of distal wall. In particular, thanks to the greater area of the inlet portion in the central zone of the distal wall, the pressure drop is lower in this central zone compared to the peripheral zones of the distal wall.

By “pressure drop”, it is in particular understood a difference of air pressure at the entrance of the air inlet portion compared with an air pressure at a transition point from the inlet portion to the heating chamber, defined along the device longitudinal axis. In other words, the pressure drop defines the air pressure difference of the airflow just before traversing the distal wall compared with the air pressure of the airflow just after traversing the distal wall, i.e. in particular when entering the heating chamber.

Depending for example on an orientation of the airflow with respect to the device longitudinal axis, a speed distribution of the airflow and/or a pressure distribution of the airflow, prior to entering the air inlet portion defined by the distal wall, the air is distributed in specific manner inside the heating chamber.

According to a first example, an airflow may enter the air inlet portion from peripheral sides, and a substantially even distribution of the airflow inside the heating chamber may be obtained, in particular an even distribution across each cross section of the heating chamber. By “airflow entering the air inlet portion from peripheral sides”, it is understood in particular that a portion of an airflow extends along a direction forming an angle greater than zero with the device longitudinal axis, for example substantially equal to 90 degrees, prior to entering the air inlet portion defined by the distal wall. By “cross section of the heating chamber”, it is in particular understood a plane extending perpendicularly to the device longitudinal axis. Thanks to the greater area of the one or several inlet holes in the central zone, and thus a lower pressure drop in this zone compared with the peripheral zones, a substantially equally amount of air may be transferred in each position of a given crosssection inside the heating chamber. If the tobacco article comprises air channels extending parallel to the device longitudinal axis, an even distribution of the airflow in the heating chamber may correspond for example to a same amount of air transmitted in each of the air channels of the tobacco article.

In particular, when the airflow coming from the peripheral sides reaches the distal wall, it may turn by around 90°, and then may be distributed substantially evenly along a width of the heating chamber, thanks to the distal wall defining the air inlet portion having a greater area in the central zone than in the peripheral zones. The width of the heating chamber is defined along a device transversal axis. The device transversal axis extends in particular perpendicular to the device longitudinal axis and connects the edges of the distal wall. For example, in cases of an air inlet portion having same areas in the central zone and in the peripheral zones of the distal wall, contrary to the air inlet portion of this disclosure, a larger amount of air would penetrate into the heating chamber via the peripheral zones for example due to the shorter length of an air path in this case compared with an air path extending via the central zone into the heating chamber. Thanks to the inlet hole(s) presenting a greater area at the central zone than at the peripheral zones, the pressure drop of the airflow is at the highest in the peripheral zones, and this balances the effect of it being the shortest path for the airflow, so that a local pressure drop in each position of a cross-section of the distal wall is the same. Thus, the aerosol generating device allows obtaining an even distribution of the airflow inside the heating chamber, leading in particular to an increased vapour extraction from the tobacco article.

According to a second example, an airflow may extend, upstream of entering the air inlet portion, along a direction substantially parallel to the device longitudinal axis. In this case, a lower amount of air may traverse the heating chamber in peripheral portions of the heating chamber compared with a central portion of the heating chamber arranged between the peripheral portions, thanks to the one or several inlet holes of the distal wall. The peripheral portions of the heating chamber are in particular portions of the heating chamber extending in extension from the peripheral zones of the distal wall, in parallel to the device longitudinal axis. The central portion of the heating chamber may be in particular the portion extending from the central zone of the distal wall, in parallel to the device longitudinal axis. Thanks to a lower amount of air traversing the heating chamber in the peripheral portions, condensation of aerosol due to cooling may be at least reduced. For example, vapour extraction may be improved and appearance of the used tobacco article may be improved thanks to these features of the distal wall, because condensation is at least reduced in the peripheral portions of the heating chamber.

The peripheral zones of the distal wall may be in particular arranged between the central zone and the corresponding edges. For example, the distal wall may define a width along the device transversal axis extending perpendicular to the device longitudinal axis and connecting the edges of the distal wall. Each peripheral zone may form in particular less than half of the width of the distal wall, from the corresponding edge of the distal wall toward the central zone. According to examples, each peripheral zone may form 49%, 40%, 33%, 30%, 20%, 10%, 5%, 2% or 1% of the width of the distal wall. The central zone may form the remaining part of the width of the distal wall. For example, if each peripheral zone forms 40% of the width of the distal wall, the central zone forms 20% of the distal wall.

By “area” of the one or several inlet holes is in particular understood an area allowing transfer of the airflow from an outside of the heating chamber into the heating chamber. For example, the area may designate a size of one or several trough-hole(s) of the distal wall into the heating chamber, corresponding to the one or several air inlet holes, in the corresponding peripheral zone or the central zone. According to an example, the size of the area may be defined by a height, such as a maximum height, of the or each inlet hole(s) in the corresponding zone. For example, in this case, a total height, or total maximum height, of the or all inlet hole(s) in the central zone may be greater than a total height or total maximum height of the or all inlet hole(s) in each peripheral zone. Each height may be in particular defined along a direction perpendicular to the device longitudinal axis and perpendicular to the device transversal axis.

According to some embodiments, the air inlet portion defines a single inlet hole having an enlarging shape from each of the edges of the distal wall toward its central zone.

Thanks to these features, the aerosol generating device may be easy to manufacture and allow obtaining an optimized airflow distribution inside the heating chamber, such as an even distribution of the airflow, in particular in cases according to which the airflow comes from peripheral sides into the single inlet hole.

The single inlet hole may have a linearly increasing shape, an exponentially increasing shape, an increasing shape in steps, such as regular steps, an increasing shape defined by a logarithmic function, or any other function increasing the shape, wherein each of such increase is defined from one of the edges of the distal wall towards the central zone.

For example, the single inlet hole may have an upper border and a lower border defining together the shape of the single inlet hole. The distance between the upper border and the lower border may increase towards the central zone, so that the shape enlarges towards the central zone of the distal wall. The distance may be defined, from the corresponding edge to the central zone, by a linear function increasing towards the central zone, increasing steps, such as regular steps, an exponential function increasing towards the central zone, a logarithmic function increasing towards the central zone, or any other derivable or non-derivable function increasing towards the central zone.

According to an example, one of the upper border and the lower border may extend along the device transversal axis perpendicular to the device longitudinal axis. In this case, the other of the upper border and the lower border may form the enlarging shape from each of the edges of the distal wall toward its central zone.

According to some embodiments, said single inlet hole has a diamond shape.

Thanks to these features, the single inlet hole may be easy to manufacture thanks to its simple shape and further allow an optimized airflow inside the heating chamber.

Moreover, due to the linear variation of the height of the inlet hole between the central zone and the peripheral zones in case of a diamond shape, the height being defined along a direction perpendicular to the device longitudinal axis and perpendicular to the device transversal axis, the distribution of the airflow inside the heating chamber is particularly even, leading to particularly increased and homogeneous vapour extraction from the tobacco article.

For example, the upper border and the lower border of the single inlet hole may have a distance from each other which increases linearly from zero at the edges of the distal wall to a maximum distance in the central zone, in particular in a centre having the same distance to each edge along the device transversal axis.

According to examples, a part of each peripheral zone may be deprived of air inlet holes, and only a part of each peripheral zone adjacent to the central zone according to the device transversal axis may comprise a fraction of the area of the single inlet hole. In other words, for example, transversal edges of the diamond shape may not be in contact with the edges of the distal wall, but arranged in positions inside the peripheral zones of the distal wall, which are between the edges and the central zone.

According to some embodiments, the air inlet portion defines a plurality of holes.

Thanks to these features, the aerosol generating device allows to distribute the airflow in predetermined parts of the heating chamber, for example depending on a shape of the flat-shaped tobacco article and/or the heating chamber, so as to allow efficient extraction of aerosol from the flat-shaped tobacco article in the heating chamber.

For example, each hole of the plurality of holes may arranged so as to face at least partially a corresponding air channel formed in the flat-shaped tobacco article if the article is inserted into the heating chamber. This allows for example even distribution of the airflow into each channel formed in the flat-shaped tobacco article.

According to some embodiments, the air inlet portion defines two elongated holes extending parallel to the device transversal axis, a first elongated hole extending between the peripheral zones of the distal wall and a second elongated hole extending only in the central zone of the distal wall.

Thanks to these features, the holes allow adapting the airflow to a specific geometry or configuration of the aerosol generating device or the aerosol generating article. For example, the first elongated hole may be adapted to face a first set of embossed air channel(s) formed in the flat-shaped tobacco article and the second elongated hole may be adapted to face a second set of embossed air channel(s) formed in the flat-shaped tobacco article. In this case, for example, the air channel(s) of the first set may have a different size and/or distribution on the aerosol generating article compared with the air channel(s) of the second set. These features allow for example providing a same or at least similar amount of air to each of the air channels formed in the flat-shaped tobacco article upon its insertion in the heating chamber.

According to some embodiments, the heating chamber further comprises two heating plates forming at least partially opposite walls of the heating chamber, the heating plates having different sizes.

Thanks to these features, the aerosol generating device allows for example heating the aerosol generating article in a very energy-efficient manner. In particular, each heating plate may be configured for heating a different surface area of the aerosol generating article.

These features are particularly advantageous if the air inlet portion defines two elongated holes extending parallel to the device transversal axis, a first elongated hole extending between the peripheral zones of the distal wall and a second elongated hole extending only in the central zone of the distal wall. In this case, for example, the size of the heating plates may be adapted to sizes of the first and second elongates holes. For example, the first hole may have a width along the device transversal axis substantially equal to a width, along the device transversal axis, of one of the heating plates, which is in particular adjacent to the first hole. The second hole may have a width, along the device transversal axis, substantially equal to a width of the other one of the heating plates, which is in particular adjacent to the second hole. In this case, in particular, the airflow inside the heating chamber may be provided thanks to these features over a total with of each of the heating plates, in particular on sides of the aerosol generating article facing the corresponding heating plates.

According to an example, the heating plates may have different areas heated by the heating plate upon of its operation. For example, these heated areas may be different from a total size of the corresponding heating plate. For example, one heating plate can have a larger area heated upon operation than the other heating plate. In this case, advantageously, the width of each of the elongated holes is substantially equal to a width of the heated area of the heating plate, which is the closest to the corresponding elongated hole.

According to some embodiments, the air inlet portion defines two peripheral holes adjacent to different edges of the distal wall and comprising at least a part having an enlarging shape from the corresponding edge of the distal wall toward its central zone.

According to some embodiments, the air inlet portion further defines at least one central hole arranged between said peripheral holes.

Thanks to these features, the aerosol generating device is easy to manufacture and furthermore each hole may allow to provide an even distribution of the airflow in corresponding channel(s) of the tobacco article for example. Thanks to the enlarging shape of at least a part of each peripheral hole, the airflow may traverse evenly each hole, i.e. for example with at constant flow rate in each position of each peripheral hole, for example if the airflow comes from peripheral sides prior to traversing the peripheral holes.

In the case of three holes, these advantages may apply to each of the holes. In addition, the central hole allows increasing an airflow into the heating chamber. According to some embodiments, the holes define substantially a same shape, advantageously a diamond shape.

Thanks to these features, the aerosol generating device is easy to manufacture, because each hole may be manufactured in the same manner.

For example, the device comprising each hole having the diamond shape presents at least some, preferably all, features and/or advantages described above for the example according to which a single inlet hole has a diamond shape.

According to some embodiments, the aerosol generating device further comprises:

- an airflow distributing chamber arranged adjacent to the distal wall and exterior to the heating chamber;

- an airflow guiding path guiding airflow from the exterior of the device until the airflow distributing chamber, the airflow guiding path opening at a periphery of the airflow distributing chamber.

Thanks to these features, an even distribution of the airflow inside the heating chamber and/or less condensation may occur in the heating chamber. For example, the airflow may be guided from the periphery of the airflow distributing chamber into the one or several inlet holes presenting a greater area at the central zone than at the peripheral zones. The airflow turns for example of around 90° so as to traverse the one or several inlet holes. Thanks to the inlet hole(s) presenting a greater area at the central zone than at the peripheral zones, the pressure drop of the airflow is at the highest in the peripheral zones, and this balances the effect of it being the shortest path for the airflow, so that a local pressure drop in each position of a cross-section of the distal wall is the same. Thus, the aerosol generating device allows obtaining an even distribution of the airflow inside the heating chamber, leading in particular to an increased vapour extraction from the tobacco article.

For example, the airflow guiding path may extend at least at one side, preferably at both sides of the heating chamber. In this case, the airflow may turn 180° before entering the one or several inlet holes, and in particular be distributed evenly inside the heating chamber. The airflow guiding path may be configured for guiding the airflow for example from one or several air inlet(s) arranged on lateral side(s) of a device body of the aerosol generating device. According to another example, or in addition, the airflow guiding path may be configured for guiding the airflow for example from one or several air inlet(s) arranged at a rear end of the device body opposite to a front end of the device body comprising at least a part of a mouthpiece intended to be in contact with the mouth and/or the lips of a user.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention and its advantages will be better understood upon reading the following description, which is given by way of non-limiting example and which is made with reference to the appended drawings, in which:

- Figure 1 is a schematic perspective view of an aerosol generating assembly, the aerosol generating assembly comprising an aerosol generating device according to the invention and an aerosol generating article usable with the aerosol generating device;

- Figure 2 is a perspective view of the aerosol generating article of Figure 1 ;

- Figure 3 is a schematic perspective view of the aerosol generating assembly of Figure 1 according to a first embodiment, wherein a device body of the aerosol generating device is omitted;

- Figure 4 is a perspective view of the aerosol generating assembly similar to the view of Figure 3, wherein the view comprises in addition a partial cross-section according to a plane IV-IV of Figure 3 so as to illustrate in particular the aerosol generating article;

- Figure 5 is a schematic view of the aerosol generating assembly of Figure 4 in direction of a device longitudinal axis;

- Figure 6 is a schematic view analogous to the view of Figure 5 of the aerosol generating assembly according to a variant of the first embodiment, and - Figure 7 is a schematic cross-sectional view of the aerosol generating assembly according to the variant of the first embodiment of Figure 6, according to a plane VII-VII of Figure 6;

- Figure 8 is a schematic view analogous to the view of Figure 5 of the aerosol generating assembly according to a second embodiment, and

- Figure 9 is a schematic view analogous to the view of Figure 5 of the aerosol generating assembly according to a third embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Before describing the invention, it is to be understood that it is not limited to the details of construction set forth in the following description. It will be apparent to those skilled in the art having the benefit of the present disclosure that the invention is capable of other embodiments and of being practiced or being carried out in various ways.

The expression “substantially equal to” is understood hereinafter as an equality at plus or minus 10% and preferably at plus or minus 5%, and even more preferably at plus or minus 1 %. According to some examples, this expression may designate exact equality.

As used herein, the term “aerosol generating device” or “device” may include a vaping device to deliver an aerosol to a user, including an aerosol for vaping, by means of a heater element explained in further detail below. The device may be portable. “Portable” may refer to the device being for use when held by a user. The device may be adapted to generate a variable amount of aerosol, e.g. by activating the heater element for a variable amount of time (as opposed to a metered dose of aerosol), which can be controlled by a trigger. The trigger may be user activated, such as a vaping button and/or inhalation sensor. The inhalation sensor may be sensitive to the strength of inhalation as well as the duration of inhalation to enable a variable amount of vapour to be provided (so as to mimic the effect of smoking a conventional combustible smoking article such as a cigarette, cigar or pipe, etc.). The device may include a temperature regulation control to drive the temperature of the heater and/or the heated aerosol generating substance (aerosol pre-cursor) to a specified target temperature and thereafter to maintain the temperature at the target temperature that enables efficient generation of aerosol. As used herein, the term “aerosol” may include a suspension of vaporizable material as one or more of: solid particles; liquid droplets; gas. Said suspension may be in a gas including air. Aerosol herein may generally refer to/include a vapour. Aerosol may include one or more components of the vaporizable material.

As used herein, the term “vaporizable material” or “precursor” may refer to a smokable material which may for example comprise nicotine or tobacco and an aerosol former. Tobacco may take the form of various materials such as shredded tobacco, granulated tobacco, tobacco leaf and/or reconstituted tobacco. Suitable aerosol formers include: a polyol such as sorbitol, glycerol, and glycols like propylene glycol or triethylene glycol; a non-polyol such as monohydric alcohols, acids such as lactic acid, glycerol derivatives, esters such as triacetin, triethylene glycol diacetate, triethyl citrate, glycerin or vegetable glycerin. In some embodiments, the aerosol generating agent may be glycerol, propylene glycol, or a mixture of glycerol and propylene glycol. The substrate may also comprise at least one of a gelling agent, a binding agent, a stabilizing agent, and a humectant.

FIRST EMBODIMENT

With reference to Figures 1 to 7, an aerosol generating assembly 10 according to a first embodiment comprises an aerosol generating device 1 1 and a flat-shaped aerosol generating article 12, also called flat-shaped tobacco article 12. The aerosol generating device 11 is intended to operate with the flat-shaped tobacco article 12 which is shown in more detail in Figure 2. The flat-shaped tobacco article 12 is called tobacco article 12 hereafter.

With reference to Figure 2, the tobacco article 12 presents for example a flat-shaped cuboid extending along an article axis X1 and having external dimensions LxWxD. In a typical example, the length L of the article 12 according to the article axis X1 equals substantially to 33 mm while its width W and depth D are substantially equal respectively to 12 mm and 1 ,2 mm. According to different examples, the values L, W and D can be selected within a range of +/- 40%, for example. More generally, the article is flat-shaped in that one of the dimensions L, W, D is significantly less than the two others. For example, if the depth D is the smallest dimension and the length L is the largest dimension among the length L, the depth D and the width W, the depth D is preferably less than a fifth of the width W, preferably less than of an eighth of the width W, preferably of the order of a tenth of the width W and the width W is preferably less than a half of the length L, preferably of the order or of less than a third of the length L.

The flat character of the tobacco article 12 is associated with a specific need of air flow repartition, namely along the width W in the examples right above since the width W is significantly larger than the depth D.

The depth D of the tobacco article 12 is formed by a pair of parallel walls 13A, 13B, called hereinafter narrow walls 13A, 13B, and the width W of the tobacco article 12 is formed by a pair of parallel walls 14A, 14B, called hereinafter wide walls 14A, 14B. In some embodiments, the edges between the wide and narrow walls 13A, 13B, 14A, 14B can be rounded. According to other embodiments of the present disclosure, the tobacco article 12 can have any other suitable flat shape and/or external dimensions.

The tobacco article 12 comprises for example a tobacco portion 15 and a mouthpiece portion 16 arranged along the article axis X1. The tobacco portion 15 may for example be slightly longer than the mouthpiece portion 16. For example, the length L2 of the tobacco portion 15 according to the article axis X1 may be substantially equal to 18 mm. The width W2 of the tobacco portion 15 is substantially equal to the width W of the tobacco article 12. The length L3 of the mouthpiece portion 16 according to the article axis X1 may be substantially equal to 15 mm. As in the previous case, the values L2 and L3 can be selected within a range of +/- 40%, for example. The tobacco portion 15 defines an abutting end 18 of the article 12 and the mouthpiece portion 16 defines a mouth end 20 of the article 12. The tobacco portion 15 and the mouthpiece portion 16 may be fixed one to the other by a wrapper 21 extending around the article axis X1. The wrapper 21 forms the narrow and wide walls 13A, 13B, 14A, 14B of the tobacco article 12. In some embodiments, the wrapper 21 is formed from a same wrapping sheet. In some other embodiments, the wrapper 21 is formed by separate wrapping sheets wrapping separately the portions 15, 16 and fixed one to the other by any other suitable mean. The wrapper 21 may, for example, comprise paper and/or non-woven fabric and/or aluminium foil. The wrapper 21 may be porous or air impermeable and forms a plurality of airflow channels extending inside the article 12 between the abutting end 18 and the mouth end 20.

The mouthpiece portion 16 comprises a core 27 intended to act for example as a cooler to cool slightly the vapour before it is inhaled by the user. The core 27 may comprise for this purpose for example corrugated paper. The core 27 may be formed through an extrusion and/or rolling process into a stable shape. Advantageously, the core 27 is arranged inside the mouthpiece portion 16 to be entirely in contact with the internal surface of the wrapper 21 delimiting this mouthpiece portion 16. Additionally or alternatively, the core 27 acts as a filter.

The tobacco portion 15 comprises a vaporizable material and is intended to be heated by a heating chamber, as it will be explained in further detail below.

According to examples, with reference to Figures 4 and 5, the tobacco portion 15 may comprise one or several embossed air channels 28 extending parallel to the article axis X1 . The air channels 28 may for example be formed on opposite faces of the tobacco portion, and have for example a constant width and/or depth along the article axis X1 . Each air channel 28 may present in particular a width and/or depth being one or several dimensions larger than an average diameter of a tobacco item of the tobacco portion 15, wherein each tobacco item is for example formed by shredded tobacco, granulated tobacco, tobacco leaf and/or reconstituted tobacco.

Referring again to Figure 1 , the aerosol generating device 1 1 comprises a device body 40 extending along a device longitudinal axis X2 between a front end 41 and a rear end 42. The aerosol generating device 1 1 further comprises a mouthpiece 43 mounted on the front end 41 of the device body 40. According to the example described below, the mouthpiece 43 and the device body 40 form two different pieces. Particularly, according to this example, the mouthpiece 43 is designed to be fixed on a support 44 defined by the front end 41 of the device body 40, as it is shown in Figure 1 . The support 44 defines for example a wall extending perpendicularly to the device longitudinal axis X2 and defining in its centre an opening for receiving the mouthpiece 43 including a heating chamber as it will be explained in further detail below. The support 44 may particularly extend inwardly from lateral walls forming the device body 40. The front end 41 of the device body 40 may for example deprived of air inlets. According to an example, the device body 40 may comprise, non-visible in Figure 1 , one or several air inlet(s) on lateral sides 45 of the device body 40 connecting the front end 41 with the rear end 42. According to another example, or in addition, the device body 40 may comprise one or several air inlet(s) on the rear end 42.

Referring to Figure 4, the mouthpiece 43 may comprise a contact part 46 configured for protruding from the front end of 41 of the device body 40, as for example illustrated in Figure 1 , when the mouthpiece 43 is mounted to the device body 40. The mouthpiece 43 may further comprise a support part 47 configured for attaching the mouthpiece 43 to the device body 40 and a holding part 48. These parts 46 to 48 are arranged successively according to the device longitudinal axis X2 and define a central hole 49 extending through each of these parts 46 to 48.

The holding part 48 is in particular designed to hold at least a part of the tobacco article 12. The holding part 48 defines in particular a heating chamber 60, as for example illustrated in Figure 4. Particularly, the holding part 48 is designed to receive through the central hole 49 at least a part of the mouthpiece portion 16 of the tobacco article 12, omitted from view in Figure 4. For this purpose, at least inside the holding part 48, the cross-section of the central hole 49 is complementary to the external shape of the mouthpiece portion 16 of the tobacco article 12. Particularly, as the tobacco article 12 is flat-shaped, the central hole 49 has also a flat shape, advantageously a rectangular flat shape.

The device body 40 delimits an internal space of the device 11 receiving various elements designed to carry out different functionalities of the device 1 1 . This internal space can for example receive a battery for powering the device 1 1 , a controller for controlling the operation of the device 11 , the heating chamber 60 for heating the tobacco portion 15 of the tobacco article 12, etc. Among these elements, only the heating chamber 60 will be explained in further detail in reference to Figures 3 to 5.

The heating chamber 60 extends along the device longitudinal axis X2 between a proximal end 62 configured to receive at least the tobacco portion 15 of the flat-shaped tobacco article 12 and a distal end 64 opposite to the proximal end 62. If the tobacco portion 15 is received in the heating chamber 60, in particular the article axis X1 may extend in parallel, or be identical to, the device longitudinal axis X2. The proximal end 62 may for example open to the central hole 49. The distal end 64 of the heating chamber 60 comprises a distal wall 66 extending between two edges 68, for example rounded edges, along a device transversal axis Y2 extending substantially perpendicularly to the device longitudinal axis X2. The device transversal axis Y2 extends in particular along a direction connecting the two edges 68 of the distal wall 66. For example, the device transversal axis Y2 extends in parallel to wide walls 72A, 72B of the heating chamber 60 defining the flat shape of the heating chamber 60. The heating chamber 60 may comprise a heating zone adapted to heat the tobacco portion 15 of the tobacco article 12 when the tobacco article is received in the heating chamber 60, in particular via the central hole 49 and the proximal end 62 of the heating chamber 60.

The heating chamber 60 has a flat shape. Particularly, as the tobacco article 12, the heating chamber 60 may also form a cuboid shape extending along the device longitudinal axis X2 and comprising, illustrated for example in Figures 3 to 5, a pair of parallel narrow walls 70A, 70B extending along the device longitudinal axis X2, a pair of parallel wide walls 72A, 72B extending also along the device longitudinal axis X2 connecting the proximal end 62 with the distal end 64, in particular with the distal wall 66. The heating chamber 60 is in particular configured to receive the tobacco article 12 so as the corresponding wide walls 14A, 14B of the tobacco article 12 face the corresponding wide walls 72A, 72B of the heating chamber 60, the corresponding narrow walls 13A, 13B of the tobacco article 12 face the corresponding narrow walls 70A, 70B of the heating chamber 60 and the abutting end 18 of the tobacco article 12 abuts against the distal wall 66 or at least a rib extending from this distal wall 66. Alternatively, the abutting end 18 faces the distal wall 66 without being in contact with it. The facing wide walls 14A, 14B, 72A, 72B and the facing narrow walls 13A, 13B, 70A, 70B can be at least partially in contact one with the other or spaced one from the other.

In the examples of figures 3 to 5, each of the edges 68 extends from an outer surface of the respective narrow wall 70A, 70B approximately up to the level of an inner surface of the respective narrow wall 70A, 70B along the device transversal axis Y2, as can be observed on figure 4.

The distal wall 66 of the heating chamber 60 defines an air inlet portion 73 configured to provide an airflow inside the heating chamber 60, as illustrated by arrows 74 in Figure 4, wherein a width of each arrow 72 corresponds to an airflow speed or flow rate for example. The air inlet portion 73 defines one or several inlet holes 76, for example a single inlet hole 76. The air inlet portion 73 may further be a portion defined, along the device longitudinal axis X2, by a wall thickness of the distal wall 66.

With reference in particular to Figure 5, the one or several inlet holes 76 present a greater area at a central zone 78 of the distal wall 66 than at peripheral zones 80 of the distal wall 66, adjacent to its edges 68. For example, with reference to Figures 3 to 5, the air inlet portion 73 defines a single inlet hole 76 having an enlarging shape from each of the edges 68 of the distal wall 66 toward its central zone 78.

Preferably the ratio of the maximum distance between any two points of the inlet hole 76, or, in case of several inlet holes 76, of all the inlet holes 76 taken as a whole, along the device transversal axis Y2 and of a length of the distal wall 66 is more than 50%, more than 60%, more than 70%, more than 80%, more preferably more than 90%.

The peripheral zones 80 of the distal wall may be in particular arranged between the central zone 78 and the corresponding edges 68. For example, the distal wall 66 may define a width W3, along the device transversal axis Y2, visible in particular in Figure 5. Each peripheral zone 80 may form in particular less than half of the width W3 of the distal wall 66, from the corresponding edge 68 of the distal wall 66 toward the central zone 78. According to examples, each peripheral zone 80 may form 49%, 40%, 33%, 30%, 20%, 10%, 5%, 2% or 1 % of the width W3 of the distal wall 66. The central zone 78 may form the remaining part of the width W3 of the distal wall 66. For example, if each peripheral zone 80 forms 40% of the width W3 of the distal wall 66, the central zone 78 forms 20% of the distal wall 66.

The single inlet hole 76 may have a linearly increasing shape, defined from each edge 68 of the distal wall 66 towards the central zone 78. For example, the single inlet hole 76 may have an upper border 82 and a lower border 84 defining together the shape of the single inlet hole 76. A distance D2, visible in particular in Figure 5, between the upper border 82 and the lower border 84 may increase towards the central zone 78, so that the shape enlarges towards the central zone 78. The distance D2 may be defined, from the corresponding edge 68 to the central zone 78, by a function, such as a linear function increasing towards the central zone 78. In case of the diamond shape as visible in Figures 3 to 5, the upper border 82 and the lower border 84 of the single inlet hole 76 may have the distance D2 from each other which increases linearly from zero at the edges 68 to a maximum distance in the central zone 78, in particular in a centre having the same distance to each edge 68 along the device transversal axis Y2.

Referring to Figure 3, the heating chamber 60 further may comprise for example at least one heating plate 90 forming at least partially one of the wide walls 72A, 72B of the heating chamber 60. Preferably, the heating chamber 60 comprised two heating plates 90 (only one is visible in Figure 3) forming at least partially the opposite wide walls 72A, 72B of the heating chamber 60. Particularly, each heating plate 90 is designed to be in contact with or face the tobacco portion 15 of the tobacco article 12. Advantageously, each heating plate 90 extends according to the whole area of a heating zone in projection on a plane parallel to each of the wide walls 72A, 72B. In other words, the length of each heating plate 90 according to the device longitudinal axis X2 is at least equal to length L2 of the tobacco portion 15 and the width of each heating plate 90 is at least equal to the width W2 of the tobacco portion 15. According to an example, the heating plates 90 may have different sizes. Each heating plate 90 may for example comprise a pair of contacts (not shown) connected to the battery of the device and heating circuits extending between the contacts along the whole surface of the corresponding plate 90. For example, the or each heating plate 90 has a substantially rectangular shape.

With reference to Figures 6 and 7, a variant of the aerosol generating assembly 10 according to the first embodiment is now described. The variant comprises at least some, preferably all, features of the first embodiment as described above. Only differences and/or additional features of the variant are described hereafter. Figure 6 is a schematic view according to a plane VI of the aerosol generating device 11 according to the variant, wherein the plane VI is visible in Figure 7. Figure 7 is a schematic view according to a plane VII of this aerosol generating device 11 , wherein the plane VII is visible in Figure 6.

The device body 40 may be closed at the rear end 42. In particular, the rear end 42 may be deprived of air inlets or outlets. The aerosol generating device 11 may further comprise an airflow distributing chamber 92 arranged adjacent to the distal wall 66 and exterior to the heating chamber 60. The aerosol generating device 1 1 may further comprise at least one airflow guiding path 94 guiding the airflow from the exterior of the device 11 until the airflow distributing chamber 92. In particular, the airflow guiding path 94 may be configured for guiding the airflow for example from one or several air inlet(s), not shown, arranged on the lateral side(s) 45 of the device body 40. The or each airflow guiding path 94 may open at a periphery of the airflow distributing chamber 92, in particular at opening(s) 96.

The airflow guiding path 94 may extend at least at one side, preferably at both sides of the heating chamber 60, in particular in parallel to the device longitudinal axis X2. In this case, the airflow may turn 180° before entering the inlet hole 76. In the examples of figures 6 and 7, the heating chamber 60 is delimited by the narrow walls 70A, 70B and the airflow guiding path is delimited by two additional narrow walls 96A, 96B framing the heating chamber 60 on either side of the narrow walls. In other words, the edges 68 extend in these cases from an outer surface of the respective additional narrow wall 96A, 96B approximately up to the level of an outer surface of the respective narrow wall 70A, 70B along the device transversal axis Y2, as can be observed on the dotted lines of figure 7.

SECOND EMBODIMENT

With reference to Figures 1 , 2 and 8, an aerosol generating assembly 10 according to a second embodiment is now described.

The aerosol generating assembly 10 according to the second embodiment comprises at least some, preferably all, features of the first embodiment as described above. Only differences of the second embodiment to the first embodiment and/or additional features of the second embodiment are described hereafter. The same reference signs may be used for identical or similar elements.

With reference to Figure 8, the air inlet portion 73 defines a plurality of holes. For example, the air inlet portion 73 may define two elongated holes 98A, 98B extending parallel to the device transversal axis Y2. For example, a first elongated hole 98A may extend between the peripheral zones 80 of the distal wall 66 and a second elongated hole 98B may extend only in the central zone 78 of the distal wall 66. In particular, due to this arrangement, the air inlet portion 73 defines several inlet holes, which are here the holes 98A, 98B, presenting together a greater area at the central zone 78 of the distal wall 66 than at the peripheral zones 80 of the distal wall 66. At least one, or each of the two elongated holes 98A, 98B may comprise at least some features of the air inlet hole 76 of the first embodiment.

According to an example, each elongated hole 98A, 98B presents a constant height, wherein the height is defined along direction perpendicular to the device longitudinal axis X2 and perpendicular to the device transversal axis Y2. For example, the elongated holes 98A, 98B may present the same height. According to another example, at least one, or both of the elongated holes 98A, 98B may present a varying height. According to some examples, the inlet portion 73 may define more than two inlet holes 76 and/or elongated holes 98A, 98B.

The heating chamber 60 may comprise for example two heating plates 90 having different sizes. In this case, for example, a width of the heating plate 90 adjacent to the first elongated hole 98A, i.e. for example the heating plate 90 of the wide wall 72B in Figure 8, may be substantially equal to the width of the first elongated hole 98A. Similarly, a width of the heating plate 90 adjacent to the second elongated hole 98B, i.e. for example the heating plate 90 of the wide wall 72A in Figure 8, may be substantially equal to the width of the second elongated hole 98B.

Preferably the ratio of a maximum distance between any two points of the inlet holes 98A and 98B taken as a whole along the device transversal axis Y2 and of a length of the distal wall 66 is more than 50%, more than 60%, more than 70%, more than 80%, more preferably more than 90%.

THIRD EMBODIMENT

With reference to Figures 1 , 2 and 9, an aerosol generating assembly 10 according to a third embodiment is now described.

The aerosol generating assembly 10 according to the third embodiment comprises at least some, preferably all, features of the first and/or second embodiment as described above. Only differences of the third embodiment to the previous embodiments and/or additional features of the third embodiment are described hereafter. The same reference signs may be used for identical or similar elements.

For example, the air inlet portion 73 may define at least two peripheral holes 99A adjacent to the different edges 68 of the distal wall 66 and comprising at least a part 100 having an enlarging shape from the corresponding edge 68 of the distal wall 66 toward the central zone 78 of the distal wall 66. In this case, for example, the part 100 of each peripheral hole 99A may define the peripheral zone of the distal wall 66. According to an example, the air inlet portion 73 may further define at least one central hole 99B arranged between the peripheral holes 99A. At least one, preferably each, of the peripheral holes 99A and the central hole 99B comprises at least some of the features of the air inlet hole 76 of the first embodiment and/or of the elongated holes 98A, 98B of the second embodiment. For example, each hole 99A, 99B may define substantially a same shape. The same shape is for example any shape of the air inlet hole 76 as described above, such as the diamond shape.

OTHER EMBODIMENTS

According to other embodiments, any features of the first, second and third embodiments may be combined in any technical feasible combination providing the air inlet portion 73 that defines one or several inlet holes 76, 98A, 98B, 99A, 99B presenting a greater area at the central zone 78 of the distal wall 66 than at the peripheral zones 80 of the distal wall 66.

For example, the aerosol generating device 11 of any of the first, second and third embodiments may comprise the one, two or more than two heating plates 90. The heating plates 90 may have different sizes.

Claims

1 . An aerosol generating device (11 ) configured to operate with a flat-shaped tobacco article (12) and comprising a flat-shaped heating chamber (60) extending along a device longitudinal axis (X2) between a proximal end (62) configured to receive at least a tobacco portion (15) of the flat-shaped tobacco article (12) and a distal end (64) opposite to the proximal end (62); wherein the distal end (64) of the heating chamber (60) comprises a distal wall (66) extending between two edges (68) along a device transversal axis (Y2) substantially perpendicularly to the device longitudinal axis (X2); the distal wall (66) defining an air inlet portion (73) configured to provide an airflow (74) inside the heating chamber (60); the air inlet portion (73) defining one or several inlet holes (76, 98A, 98B, 99A, 99B) presenting a greater area at a central zone (78) of the distal wall (66) than at peripheral zones (80) of the distal wall (66), adjacent to its edges (68).

2. The aerosol generating device (1 1 ) according to claim 1 , wherein the air inlet portion (73) defines a single inlet hole (76) having an enlarging shape from each of the edges (68) of the distal wall (66) toward its central zone (78).

3. The aerosol generating device (11 ) according to claim 2, wherein said single inlet hole (76) has a diamond shape.

4. The aerosol generating device (1 1 ) according to claim 1 , wherein the air inlet portion (73) defines a plurality of holes (76, 98A, 98B, 99A, 99B).

5. The aerosol generating device (1 1 ) according to claim 4, wherein the air inlet portion (73) defines two elongated holes (98A, 98B) extending parallel to the device transversal axis (Y2), a first elongated hole (98A) extending between the peripheral zones (80) of the distal wall (66) and a second elongated hole (98B) extending only in the central zone (78) of the distal wall (66).

6. The aerosol generating device (1 1 ) according to claim 5, wherein the heating chamber (60) further comprises two heating plates (90) forming at least partially opposite walls (72A, 72B) of the heating chamber (60), the heating plates (90) having different sizes.

7. The aerosol generating device (1 1 ) according to claim 4, wherein the air inlet portion (73) defines two peripheral holes (99A) adjacent to different edges (68) of the distal wall (66) and comprising at least a part (100) having an enlarging shape from the corresponding edge (68) of the distal wall (66) toward its central zone (78).

8. The aerosol generating device (1 1 ) according to claim 7, wherein the air inlet portion (73) further defines at least one central hole (99B) arranged between said peripheral holes (99A).

9. The aerosol generating device (11 ) according to claim 7 or 8, wherein said holes (99A, 99B) define substantially a same shape, advantageously a diamond shape.

10. The aerosol generating device (1 1 ) according to any one of the preceding claims, further comprising:

- an airflow distributing chamber (92) arranged adjacent to the distal wall (66) and exterior to the heating chamber (60);

- at least one airflow guiding path (94) guiding the airflow from the exterior of the device (1 1 ) until the airflow distributing chamber (92), the airflow guiding path (94) opening at a periphery of the airflow distributing chamber (92).