Patent Description:
Particularly, the aerosol generating device according to the invention is configured to operate with an aerosol generating article, for example a flat-shaped tobacco article, which 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.

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 <NUM> to <NUM>. 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.

Tobacco articles, usable with such type of aerosol generating devices can take various forms. Some of them can present an elongated stick or any other suitable shape, like for example a flat shape. Generally, such a tobacco article is received at least partially in a heating chamber of the device which comprises one or several heaters to heat the tobacco article.

Documents <CIT> and <CIT> disclose aerosol generating devices with flat shaped heating chambers.

Heating efficiency by the heating chamber is thus an important operation parameter of the aerosol generating device. In some aerosol generating devices, heat generated by the heating chamber can be dissipated. This can cause not only under-heating of the tobacco article and as a consequence a poor vapour generation, but in some cases also over-heating of the device body and notably of a zone of the device body used to handle the device by the user. This can conduct to a poor user experience.

One of the aims of the invention is to propose an aerosol generating device providing a better heating efficiency of an aerosol generating article and as a consequence, a better user experience. Thus, the quality of vapour generation can be increased while reducing the device body over-heating.

For this purpose, the invention relates to an aerosol generating device comprising a device body and a heating chamber configured to receive at least partially an aerosol generating article;.

Thanks to these features, the heating chamber is attached to the device body only in the mounting zone. Thus, the mounting zone forms the only heat transfer zone between the heating chamber and the device body. Heat transfer can thus be minimized by optimizing the structure of the mounting zone. For this purpose, the mounting zone can be configured to be engaged with the support of the device body using optimized means. These means can be optimized to minimize heat transfer between the heating chamber and the device body.

In some embodiments, the means attaching the heating chamber to the device body can be configured to be easily disengaged by the user. Thus, the heating chamber can be detached from the device body to be for example cleaned or replaced by the user.

Additionally, thanks to its flat shape, the heating chamber is adapted to receive an aerosol generating article having a flat shape. The flat shape of the heating chamber is particularly advantageous to ensure a fast preheating phase of the aerosol generating article. Thus, the article can be ready to generate vapor only a few seconds (for example <NUM> or <NUM> or <NUM>) after activating the heating chamber. The flat shape of the heating chamber is also advantageous to ensure a relatively great amount of vapor and homogeneous heating of the aerosol generating article during a vaping phase.

Furthermore, the or each protruding part extends according to the central plane to reduce the size of the device body and keep it also substantially flat. For example, the flat shape of the heating chamber can extend according to the central plane. In this case, the or each protruding part extends according to this plane without breaking the flat shape of the device body receiving the heating chamber. Thus, the device body can be only slightly thicker than the heating chamber.

According to some embodiments, the mounting zone and the heating zone form opposite ends of the heating chamber.

Thanks to these feature, the distance between the mounting zone and the heating zone of the heating chamber can be maximized, minimizing thus heat transfer from the heating zone to the mounting zone. Provided with this structure, the heating chamber can be seen as a floating structure inside the device body which is attached to this body only at one of its ends.

According to some embodiments, the mounting zone is engaged with the support by means of two protruding parts,.

Thanks to these features, the heating chamber can be solidary attached to the support.

According to some embodiments, the mounting zone is engaged with the support by means of only two protruding parts engaged with two respective pins.

Thanks to these features, the number of contact points between the heating chamber and the device body can be minimized. Thus, heat transfer from the heating chamber to the device body can further be decreased.

According to some embodiments, the or each protruding part is engaged with a pin.

The or each pin can be formed either by the mounting zone of the heating chamber or by the support of the device body. Respectively, the or each protruding part can be formed either by the support of the device body or the mounting zone of the heating chamber.

The or each pin can has a thin cylindrical shape that minimizes its contact surface with the corresponding protruding part while ensuring a secure fixation. Thus, heat transfer between the pin and the corresponding protruding part can be minimized. Additionally, since each protruding part protrudes from the corresponding surface of the support or the mounting zone, heat transfer toward this surface can also be minimized.

According to some embodiments, the or each protruding part comprises a mounting ear configured to receive the corresponding pin.

A mounting ear presents a particularly advantageous structure to be engaged with a pin. Particularly, the mounting ear can define a central hole having a lateral opening. The pin can be engaged laterally inside the central hole using the lateral opening. Thus, the heating chamber can be easily fixed to the device body. Additionally, the mounting ear structure can be configured to easily disengage the pin and detach the heating chamber from the device body. Additionally, contact surface between a mounting ear and a pin can be minimized while ensuring a secure fixation. Thus, heat transfer from the heating chamber to the device body can further be minimized.

According to some embodiments, the mounting zone of the heating chamber forms said protruding part(s) and the support of the device body forms said pin(s).

This respective arrangement of the pin(s) and the protruding part(s) is particularly advantageous since the protruding part(s) can be arranged outwardly in respect with an external surface of the heating chamber and the pin(s) can be easily arranged inside the device body to be engaged with the corresponding protruding part(s).

According to some embodiments, the aerosol generating device further comprises an airflow channel, the airflow channel comprising an upstream part extending through the mounting zone and a downstream part designed to extend through the aerosol generating article when it is inserted into the heating chamber.

Thanks to these features, fresh air aspired for the exterior of the aerosol generating device can cool the mounting zone before being heated by the heating chamber in the downstream part of the airflow channel. Since the mounting zone is permanently cooled while the aerosol generating device is operating to generate aerosol, heat transfer between the heating chamber and the device body can further be minimized.

For this purpose, for example, the airflow channel can form one or several air inlets in the vicinity of the mounting zone. The upstream part of the airflow channel can be formed by one or several branches extending between said one or several air inlets until a closed end of the heating chamber. The upstream part can extend at least partially interior and/or exterior to the heating chamber. The downstream part of the flow channel can extend from the closed end of the heating chamber and then, through the aerosol generating article before achieving the user's lips or mouth.

According to some embodiments, the aerosol generating device further comprises a mouthpiece mounted on the open end of the device body, and a seal arranged between the mounting zone and the mouthpiece.

Thanks to these features, it is possible to avoid leakages between an edge of the mouthpiece and the heating chamber. Additionally, the seal provides a thermal break between the heating chamber and the mouthpiece minimizing thus heat transfer from the heating chamber to the mouthpiece. The seal can be made of silicone for example.

According to some embodiments, the mouthpiece is fixed to the device body using fixing means, advantageously magnetic fixing means.

Thanks to these features, the mouthpiece can be securely attached to the device body. Additionally, using these fixing means, the mouthpiece can exert pressure toward the heating chamber to secure its fixation inside the device body. The pressure can for example be exerted through the seal provided between the mouthpiece and the heating chamber.

According to some embodiments, the mouthpiece comprises:.

The seal can for example be provided under the support part of the mouthpiece and can extend along a periphery of the opening formed by the heating chamber. Additionally, when the upstream part of the airflow channel extends through the mounting zone of the heating chamber, the air inlet(s) can be arranged on the support part of the mouthpiece.

According to some embodiments, a thermal break is provided between the support part and the contact part of the mouthpiece.

This thermal break can for example be formed by a groove extending between the support part and the contact part, for example around a central hole of the mouthpiece. Thanks to this thermal break, heat transfer of the support part which is arranged closer to the heating chamber than the contact part, can be minimized.

According to some embodiments, the mouthpiece further comprises a holding part designed to hold at least a part of the aerosol generating article inside the heating chamber.

The holding part can for example be configured to hold a mouthpiece portion of the aerosol generating article. In some embodiments, before inserting the aerosol generating device in the heating chamber, the mouthpiece is unmounted and the mouthpiece portion of the aerosol generating article is inserted inside the mouthpiece. Then, the mouthpiece together with the aerosol generating article can be mounted on the device and the corresponding part of the aerosol generating article can be inserted inside the heating chamber. This part of the tobacco generating article can be at least partially in contact with walls of the heating chamber and/or form a gap with at least some of these walls.

According to some embodiments, an air gap is formed between walls of the heating chamber in the mounting zone and the holding part of the mouthpiece.

Thanks to these features, the mouthpiece can be further thermally isolated from the walls of the heating chamber and heat transfer from the heating chamber to the mouthpiece can further be minimized. To form this air gap, the heating chamber can present an enlarged section near its open end.

According to some embodiments, the contact part of the mouthpiece presents a cross-section narrowing from the support part.

This decreases the thermal mass of the mouthpiece and as a consequence, undesired heat absorption by the mouthpiece. Additionally, this ensures an ergonomic shape of the mouthpiece to enable a better contact of the user's lips or mouth with the mouthpiece.

According to some embodiments, the heating chamber further comprises a thermal insulator arranged between the heating zone and the mounting zone.

Such thermal insulator can for example be arranged on an external surface of the heating chamber. Its shape, size and dimensions can be adapted to different respective examples of arrangement of the heating and mounting zones. This thermal insulator can be formed by vacuum or an air chamber, a sheet(s), powders, etc., and can comprise various materials such superwool, aerogel, etc..

In some embodiments, a thermal insulator can be provided between the heating chamber and an internal surface of walls forming the device body. This thermal insulator can be formed by vacuum or an air chamber, a sheet(s), powders, etc., and can comprise various materials such superwool, aerogel, etc..

According to some embodiments, the heating chamber further comprises at last one heating surface arranged adjacent to the heating zone, the heating surface comprising a pair of contacts.

In some embodiments, the heating surface can be formed by a plate made at least partially from ceramics comprising heating circuit passing through the plate. The heating circuits are connected to a battery of the device with said pair of contacts. In some other embodiments, the heating surface is formed by a flexible film attached for example to a plate forming a wall of the heating chamber. According to still another embodiment, a long strip of flexible heater comprising two separate track patterns is wound around the heating chamber so those two patterns form at least one or several heating surfaces.

Advantageously, the heating chamber and the aerosol generating article form a flat shape.

By "flat shape" of the heating chamber or of the aerosol generating article, it is understood that it extends between two first parallel longitudinal planes and two second parallel longitudinal planes perpendicular to the first parallel longitudinal planes, the distance between the second parallel longitudinal planes being at least <NUM> times, advantageously <NUM> times and preferably <NUM> times, greater than the distance between the first parallel longitudinal planes.

According to some embodiments, the two protruding parts presenting for example mounting ears are arranged opposite to each other in a central plane arranged between the first parallel longitudinal planes at equal distances, said first parallel longitudinal planes delimiting the flat shape of the heating chamber. In other words, the central plane is arranged parallel to the first longitudinal planes. The central plane forms for example a plane of symmetry of the heating chamber.

Such arrangement of the protruding parts is particularly advantageous for the heating chamber having a flat-shape. Providing with the arrangement of the protruding parts, the heating chamber can be securely attached inside the device body while ensuring a flat and an ergonomic shape of the device body.

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:.

The expression "substantially equal to" is understood hereinafter as an equality at plus or minus <NUM>% and preferably at plus or minus <NUM>%.

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.

<FIG> shows an aerosol generating assembly <NUM> comprising an aerosol generating device <NUM> and an aerosol generating article <NUM>, also called tobacco article <NUM>. The aerosol generating device <NUM> is intended to operate with the tobacco article <NUM> which is shown in more detail in <FIG>.

In the example of this <FIG>, the tobacco article <NUM> is a flat-shaped tobacco article presenting for example a flat-shaped cuboid extending along an article axis X and having external dimensions LxWxD. In a typical example, the length L of the article <NUM> according to the article axis X equals substantially to <NUM> while its width W and depth D are substantially equal respectively to <NUM> and <NUM>,<NUM>. According to different examples, the values L, W and D can be selected within a range of +/- <NUM>%, for example. The depth D of the tobacco article <NUM> is formed by a pair of parallel walls 13A, 13B, called hereinafter narrow walls 13A, 13B, and the width W of the tobacco article <NUM> 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 invention, the tobacco article <NUM> can have any other suitable flat shape and/or external dimensions. According to still other embodiments, the tobacco article <NUM> can present any other suitable shape, as for example a stick shape, having substantially circular or oval cross-section.

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

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

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

Referring again to <FIG>, the aerosol generating device <NUM> comprises a device body <NUM> extending along a device axis Y between an open end <NUM> and a closed end <NUM>. The aerosol generating device <NUM> further comprises a mouthpiece <NUM> mounted on the open end <NUM> of the device body <NUM>. According to the example described below, the mouthpiece <NUM> and the device body <NUM> form two different pieces. Particularly, according to this example, the mouthpiece <NUM> is designed to be fixed on a support <NUM> defined by the open end <NUM> of the device body <NUM>, as it is shown in <FIG>. The support <NUM> defines for example a wall extending perpendicularly to the device axis Y and defining in its centre an opening to the heating chamber as it will be explained in further detail below. The support <NUM> may particularly extend inwardly from lateral walls forming the device body <NUM>.

Referring to <FIG>, the mouthpiece <NUM> comprises a contact part <NUM>, a support part <NUM> and a holding part <NUM>. These parts <NUM> to <NUM> are arranged successively according to the device axis Y and define a central hole <NUM> extending through each of these parts <NUM> to <NUM>. The contact part <NUM> and the holding part <NUM> protrudes from different sides of the support part <NUM>, according to the device axis Y.

The support part <NUM> of the mouthpiece <NUM> forms for example a collar covering partially the open end <NUM> of the device body <NUM>. The collar defines an external surface extending for example substantially perpendicularly to the device axis Y and an internal surface opposite to the external surface and facing the open end <NUM> of the device body <NUM>. The support part <NUM> is designed to be fixed on the support <NUM> of the device body <NUM> using any suitable fixing means <NUM>. In the example of <FIG>, the fixing means <NUM> comprise a first magnetic element arranged at the periphery of the support <NUM> and a second magnetic element arranged for example on the internal surface of the support part <NUM> of the mouthpiece <NUM>. At least one of the first and the second magnetic elements comprises for example a permanent magnet whereas the other element comprises a permanent magnet of opposed polarity and/or a ferromagnetic material. It is clear that the fixing means <NUM> can have any other appropriate structure suitable to fix the mouthpiece <NUM> to the device body <NUM>.

The contact part <NUM> of the mouthpiece <NUM> is designed to be in contact with the user's lips and/or mouth. For this purpose, it can form an appropriate ergonomic shape. Advantageously, the contact part <NUM> has a narrowing shape from the support part <NUM> toward its top surface, along the device axis Y. For example, the contact part <NUM> can have a shape of truncated cone. On its top surface, the contact part <NUM> forms an air outlet extending the central hole <NUM> and adapted to deliver aerosol formed in the heating chamber as it will be explained in further detail below. Advantageously, as it can be seen in <FIG>, a thermal break <NUM> is formed between the contact part <NUM> and the support part <NUM> of the mouthpiece <NUM>. The thermal break <NUM> is formed for example by a groove extending around the central hole <NUM> and formed in a connection zone between the support part <NUM> and the contact part <NUM> of the mouthpiece <NUM>. The thermal break <NUM> minimizes the contact area and/or connection part between the contact part <NUM> and the support part <NUM> of the mouthpiece <NUM>.

The holding part <NUM> is designed to hold at least a part of the tobacco article <NUM> inside the heating chamber <NUM>, as it is shown in <FIG>. Particularly, the holding part <NUM> is designed to receive in the central hole <NUM> at least a part of the mouthpiece portion <NUM> of the tobacco article <NUM>, as it is shown in <FIG>. For this purpose, at least inside the holding part <NUM>, the cross-section of the central hole <NUM> is complementary to the external shape of the mouthpiece portion <NUM> of the tobacco article <NUM>. Particularly, in case of a flat-shape tobacco article <NUM>, the central hole <NUM> has also a flat shape, advantageously a rectangular flat shape. Advantageously, as it is shown in <FIG>, the holding part <NUM> forms an air gap with walls of the heating chamber <NUM>. For this purpose, the heating chamber <NUM> may define an enlarged section adjacent to an open end of the chamber <NUM>. Particularly, this enlarged section has an enlarged cross-sectional shape in comparison with the cross-sectional shape of the part of the heating chamber <NUM> receiving the tobacco portion <NUM> of the tobacco article <NUM>, i.e. in comparison with the part of the heating chamber <NUM> adjacent to its closed end.

The device body <NUM> delimits an internal space of the device <NUM> receiving various elements designed to carry out different functionalities of the device <NUM>. This internal space can for example receive a battery for powering the device <NUM>, a controller for controlling the operation of the device <NUM>, a heating chamber <NUM> for heating the tobacco portion <NUM> of the tobacco article <NUM>, etc. Among these elements, only the heating chamber <NUM> will be explained in further detail in reference to <FIG>.

Particularly, as it is shown in <FIG>, the heating chamber <NUM> defines a mounting zone <NUM> adapted to attach the heating chamber <NUM> to the device body <NUM> and a heating zone <NUM> adapted to heat the tobacco portion <NUM> of the tobacco article <NUM>. Additionally, as it is shown in <FIG>, the mounting zone <NUM> is also adapted to receive at least partially the mouthpiece portion <NUM> of the tobacco article <NUM>. In the preferred example, the heating chamber <NUM> has a flat shape. Particularly, as the tobacco article <NUM>, the heating chamber <NUM> may also form a cuboid shape extending along the device axis Y and comprising a pair of parallel narrow walls 63A, 63B (shown in <FIG>) extending along the device axis Y, a pair of parallel wide walls 64A, 64B (partially shown in <FIG>) extending also along the device axis Y and a bottom wall <NUM> adjacent to each of said walls and extending perpendicularly to the device axis Y.

The bottom wall <NUM> forms thus a closed end of the chamber <NUM>. The heating zone <NUM> of the heating chamber <NUM> is adjacent to the closed end of the heating chamber <NUM>. Opposite to the bottom wall <NUM>, the heating chamber <NUM> defines an open end configured to receive the tobacco article <NUM> so as the corresponding wide walls 14A, 14B of the tobacco article <NUM> face the corresponding wide walls 64A, 64B of the heating chamber <NUM>, the corresponding narrow walls 13A, 13B of the tobacco article <NUM> face the corresponding narrow walls 63A, 63B of the heating chamber <NUM> and the abutting end <NUM> of the tobacco article <NUM> abuts against the bottom wall <NUM> or at least a rib extending from this bottom wall <NUM>. Alternatively, the abutting end <NUM> faces the bottom wall <NUM> without being in contact with it. The flat-shaped heating chamber <NUM> is thus configured to receive the tobacco article <NUM> so as the narrow wall 13A (respectively 13B) of the tobacco article <NUM> faces the narrow wall 63B (respectively 63A) of the heating chamber <NUM>, and the wide wall 14A (respectively 14B) of the tobacco article <NUM> faces the wide wall 64B (respectively 64A) of the heating chamber <NUM>. The facing wide walls 14A, 14B, 64A, 64B and the facing narrow walls 13A, 13B, 63A, 63B can be at least partially in contact one with the other or spaced one from the other. In the preferred example, the facing narrow walls 13A, 13B, 63A, 63B form a gap between them suitable for conducting an airflow, as it will be explained in further detail below. The mounting zone <NUM> of the heating chamber <NUM> is adjacent to the open end of the heating chamber <NUM>.

The narrow walls 63A, 63B and/or the wide walls 64A, 64B are shaped to form the enlarged section of the heating chamber <NUM> as explained above. For this purpose, the narrow walls 63A, 63B and/or the wide walls 64A, 64B can extend substantially parallel between them with a first distance d1 (respectfully D1) through the heating zone <NUM> of the heating chamber <NUM>, then form a shoulder section enlarging this distance d1 (respectfully D1) to a distance d2 (respectfully D2) and then extend parallel between them with the distance d2 (respectfully D2) through the mounting zone <NUM> of the heating chamber <NUM>. Thus, the enlarged section can substantially correspond to the mounting zone <NUM> of the heating chamber <NUM>.

The heating chamber <NUM> together with the device body <NUM> and the mouthpiece <NUM> defines an airflow channel <NUM> passing through the device <NUM> and the tobacco article <NUM> between one or several air inlets <NUM> until an air outlet <NUM> extending the central hole <NUM> as explained above. Particularly, as it is shown in <FIG>, the airflow channel <NUM> comprises an upstream part extending between the air inlets <NUM> and the closed end of the heating chamber <NUM>, and a downstream part extending between the closed end of the heating chamber <NUM> and the air outlet <NUM>. The downstream part extends advantageously through both tobacco and mouthpiece portions <NUM>, <NUM> of the tobacco article <NUM>. It can also extend through the central hole <NUM> formed by the mouthpiece <NUM>. The upstream part extends advantageously through the mouthpiece <NUM> and then inside the heating chamber <NUM>, advantageously through the mounting zone <NUM> and the gaps formed between the facing narrow walls 13A, 13B, 63A, 63B, before achieving the closed end of the heating chamber <NUM>. At the closed end, the upstream part of the airflow channel turns at substantially <NUM>° to join the downstream part. According to other embodiments, the upstream part of the airflow channel <NUM> passes entirely outside the heating chamber <NUM> and joins the downstream part for example through holes formed at the closed end of the heating chamber <NUM>.

As it is shown in <FIG>, the air inlets <NUM> can be formed on the external surface of the support part <NUM> of the mouthpiece <NUM>. Particularly, these air inlets <NUM> can be formed by holes extending through the support part <NUM> of the mouthpiece <NUM> and opening to the enlarged section of the heating chamber <NUM>. For this purpose, the holes inside the support part <NUM> can for example be inclined in respect with the device axis Y. Advantageously, the support part <NUM> defines two holes forming the air inlets <NUM> on different sides of the contact part <NUM> having an elongated shape.

Advantageously, the mounting zone <NUM> forms the unique attaching zone of the heating chamber <NUM> to the device body <NUM>. For this purpose, the mounting zone <NUM> comprises a pair of protruding parts 80A, 80B extending outwardly from the narrow walls 63A, 63B of the heating chamber <NUM> as it is shown in <FIG>. Each protruding part 80A, 80B is configured to be engaged with a pin 82A, 82B fixed to the device body <NUM>. Particularly, each pin 82A, 82B can extend perpendicularly to the device axis Y, for example perpendicularly to a plane parallel to the wide walls 64A, 64B of the heating chamber <NUM>. Each protruding part 80A, 80B can form a mounting ear defining a lateral opening configured to receive the corresponding pin 82A, 82B to attach the heating chamber <NUM>. Thus, each mounting ear extends partially around the corresponding pin 82A, 82B, for example according to an angle comprised between <NUM>° and <NUM>°.

According to some embodiments, the heating chamber <NUM> further comprises a thermal insulator arranged between the heating zone <NUM> and the mounting zone <NUM> for example on the external surface of the walls 63A, 63B, 64A, 64B delimiting the heating chamber <NUM>. Such thermal insulator can for example comprise superwool or aerogel. Alternatively, this thermal insulator can be formed by vacuum or an air chamber, a sheet(s), powders, etc..

Referring to <FIG>, the heating chamber <NUM> further comprises at least one heating surface <NUM> forming at least partially one of the wide walls 64A, 64B of the heating chamber <NUM>. Preferably, the heating chamber <NUM> comprised two heating surfaces <NUM> (only one is visible in <FIG>) forming at least partially the opposite wide walls 64A, 64B of the heating chamber <NUM>. Particularly, each heating surface <NUM> is designed to be in contact with or face the tobacco portion <NUM> of the tobacco article <NUM>, in the heating zone <NUM> of the heating chamber <NUM>. Advantageously, each heating surface <NUM> extends according to the whole area of the heating zone <NUM> in projection on a plane parallel to each of the wide walls 64A, 64B. In other words, the length of each heating surface <NUM> according to the device axis Y is at least equal to length L2 of the tobacco portion <NUM> and the width of each heating surface <NUM> is at least equal to the width W2 of the tobacco portion <NUM>.

The or each heating surface <NUM> can be formed by a plate forming the corresponding wide wall 64A, 64B of the heating chamber <NUM>. According to another embodiment, the or each heating surface <NUM> is formed by a flexible film attached for example to a plate forming the corresponding wall 64A, 64B of the heating chamber <NUM>. According to still another embodiment, the or each heating surface <NUM> is formed by a long strip of flexible heater comprising two separate track patterns and wound around the heating chamber <NUM>.

Each heating surface <NUM> comprises a pair of contacts <NUM> connected to the battery of the device and heating circuits <NUM> extending between the contacts along the whole heating surface <NUM>.

Claim 1:
An aerosol generating device (<NUM>) comprising a device body (<NUM>) and a heating chamber (<NUM>) configured to receive at least partially an aerosol generating article (<NUM>);
the device body (<NUM>) extending along a device axis (Y) between an open end (<NUM>) and a closed end (<NUM>), the open end (<NUM>) defining a support (<NUM>);
the heating chamber (<NUM>) extending along the device axis (Y) and comprising a heating zone (<NUM>) adapted to heat at least a part of the aerosol generating article (<NUM>) and a mounting zone (<NUM>) arranged successively with the heating zone (<NUM>) along the device axis (Y); wherein the heating chamber (<NUM>) forms a flat shape extending between two first parallel longitudinal planes;
characterised in that
the mounting zone (<NUM>) is engaged with the support (<NUM>) to form an attaching zone of the heating chamber (<NUM>) to the device body (<NUM>), said attaching zone being the only attaching zone of the heating chamber (<NUM>) to the device body (<NUM>);
wherein the mounting zone (<NUM>) is engaged with the support (<NUM>) by means of at least one protruding part (80A, 80B);
and
wherein said at least one protruding part (80A, 80B) extends according to a central plane arranged between the first parallel longitudinal planes.