Aerosol generating device having a heating chamber adapted for convection heating - Patents.com

Abstract

The present invention provides an aerosol generation device (10) configured to operate with a tobacco article (12) having a substrate portion (15) and a gripping portion (16) arranged successively along an article axis, the aerosol generation device (10) comprising: a heating chamber (70) extending along a chamber axis (Z) and configured to accommodate the substrate portion of the tobacco article, the heating chamber (70) comprising a heater extending along the chamber axis (Z); and a maintaining structure (74) configured to engage the gripping portion (16) of the tobacco article to maintain the substrate portion (15) of the tobacco article at a distance (G) from the heater within the heating chamber (70).

Description

[Technical field]

[0001] The present invention relates to an aerosol generating device comprising a heating chamber containing a tobacco article.

[0002] The aerosol generating device according to the invention is configured to work with a tobacco article, also indicated as an aerosol-generating substrate or aerosol substrate, which provides, for example, a solid substrate capable of forming an aerosol upon heating. Thus, this type of aerosol generating device, also known as a non-heated combustion device, is adapted to heat, by conduction, convection and / or radiation, rather than burning, the substrate, to generate an aerosol for inhalation. [Background technology]

[0003] The popularity and use of risk reduction or risk modification devices (also known as vaporizers) has grown rapidly in recent years as an aid to assist habitual smokers who wish to quit smoking traditional tobacco products such as cigarettes, cigars, cigarillos and rolling cigarettes. A variety of devices and systems are available that heat or warm a vaporizable substance, as opposed to burning tobacco in traditional tobacco products.

[0004] Commonly available risk reduction or modification devices are aerosol generating devices or non-combustion heating devices that heat a substrate. This type of device typically generates an aerosol or vapor by heating an aerosol substrate, typically comprising moist tobacco or other suitable vaporizable material, to a temperature typically ranging from 150°C to 350°C. By heating, rather than burning or combusting, the aerosol substrate, an aerosol is released that contains the ingredients desired by the user, but does not contain the toxic and carcinogenic by-products of combustion and burning. Furthermore, aerosols generated by heating tobacco or other vaporizable material typically do not contain the burnt or bitter taste resulting from combustion and burning, which can be unpleasant to the user. Thus, the substrate does not require sugars and other additives that are typically added to such materials to make the smoke and / or vapor more palatable to the user.

[0005] The aerosol substrate represents a consumable part of the aerosol generating device. Thus, when the aerosol substrate is no longer capable of producing an aerosol or / and the desired taste sensation, the user must replace it with another one. In some aerosol generating devices, replacing the aerosol generating substrate with a new one can be cumbersome for the user. In addition, some aerosol generating substrates may leave residues inside the device, which may deteriorate the operation of the device.

[0006] Aerosol generating devices typically include a heating element that heats the aerosol substrate. The heating element generates localized heat peaks during operation. Areas of the aerosol substrate are too hot while other areas are not hot enough. Thus, the aerosol substrate does not generate the desired aerosol. The aerosol substrate is subjected to inadequate heating. Summary of the Invention [Problem to be solved by the invention]

[0007] One object of the present invention is to improve the heating conditions of an aerosol substrate in an aerosol generating device. [Means for solving the problem]

[0008] To this end, the present invention provides an aerosol generating device adapted to operate with a tobacco article comprising a substrate portion and a gripping portion arranged successively along an article axis, the device comprising: - a heating chamber extending along a chamber axis and configured to accommodate a substrate portion of a tobacco article, the heating chamber comprising a heater extending along the chamber axis; - a retaining structure configured to engage a gripping portion of the tobacco article to maintain a substrate portion of the tobacco article at a distance from a heater within a heating chamber.

[0009] Advantageously, the substrate portion is the inherent tobacco-containing portion of the tobacco article: no further tobacco-containing material is provided within the device.

[0010] Thanks to these features, there is no contact between the heater and the substrate part. The temperature of the substrate part is therefore uniform. Thermal peaks are avoided and heating conditions are kept at optimum. Furthermore, the risk of damage to the substrate part due to the accumulation of residues in the heating chamber is avoided.

[0011] According to some embodiments, the aforementioned distances are adapted to ensure convective heat transfer from the heater to the substrate portion of the tobacco article.

[0012] These features result in essentially or only convection heating occurring between the heater and the aerosol substrate.

[0013] According to some embodiments, the aforementioned distances are formed according to an axis perpendicular to the chamber axis.

[0014] According to some embodiments, the retaining structure is located external to the heating chamber.

[0015] Thanks to these features, heat transfer to and through the support structure is reduced. The support structure stays cooler. Compactness is also improved.

[0016] According to some embodiments, the heating chamber defines an open end usable for inserting the substrate portion of the tobacco article into the heating chamber, and the retaining structure is disposed adjacent to or facing the open end of the heating chamber.

[0017] By virtue of these features, the open end facilitates easy replacement of the tobacco article, as well as the location of the retention structure.

[0018] According to some embodiments, the retention structure defines a receiving cavity extending along the chamber axis and configured to be capable of receiving and retaining a gripping portion of a tobacco article along the chamber axis.

[0019] By virtue of these features, the retaining structure is therefore adapted to set the distance and maintain the gap to the heater, and in addition has a fixed position along the chamber axis such that the substrate still faces the heater so as to be heated as required.

[0020] According to some embodiments, the containment cavity defines an opening, and a flow channel extends from the heating chamber through the containment cavity to the opening.

[0021] Thanks to these features, the containment cavity combines the function of providing an air passage for the aerosol formed by the substrate portion with the function of arranging the tobacco product.

[0022] According to some embodiments the retention structure is formed by the mouthpiece.

[0023] Thanks to these features, the mouthpiece serves at least two functions: The device architecture exhibits fewer elements, which makes it less expensive and easier to assemble.

[0024] According to some embodiments, the retention structure is removable from the housing of the device.

[0025] Thanks to these features, it is easier to open the heating chamber, which allows for easy replacement of the tobacco article.

[0026] According to some embodiments, the retention structure is configured to engage a gripping portion of the tobacco article when it is removed from the housing of the device.

[0027] Thanks to these features, it is easier to grasp the used tobacco article during replacement as it automatically exits the housing, which limits the risk of losing, breaking or bending the used tobacco article. The same advantage accrues when loading and placing a new tobacco article into the device.

[0028] According to some embodiments, the tobacco article is a plate-shaped tobacco article and the heater comprises a heating plate, advantageously two heating plates facing each other.

[0029] A tobacco article having a plate-like shape can be easily handled by a user. In particular, the tobacco article can be easily inserted into and removed from the heating chamber. It is also possible to reduce the size of the tobacco article, which allows the size of the heating chamber and therefore the entire device to be reduced. The heater, which comprises at least one heating plate, can extend along the entire area of ​​the substrate portion of the tobacco article to optimize heat transfer. In addition, by using two heating plates, both sides of the tobacco article are heated. Thus, the heating is uniform.

[0030] According to some embodiments, the retaining structure is configured to maintain the substrate portion of the tobacco article within the heating chamber at a distance from each heating plate.

[0031] Thanks to these features, heating becomes much more uniform.

[0032] According to some embodiments, the maintaining structure is configured to maintain the substrate portion of the tobacco article the same distance from each heating plate within the heating chamber.

[0033] Thanks to these features, each of the top and bottom surfaces of the tobacco article reaches the same temperature. Uniform heating is more precise.

[0034] According to some embodiments, the heating chamber encloses a looped free space configured to surround the substrate portion of the tobacco article.

[0035] Thanks to these features, the substrate portion is essentially enveloped by hot air and avoids contact with hot surfaces.

[0036] According to some embodiments, the heating chamber is configured to be out of contact with the free ends of the substrate portions.

[0037] Thanks to these features, portions of the substrate are not exposed to the excessively hot surfaces of the heating chamber.

[0038] The invention and its advantages will be better understood on reading the following description, which is given purely as a non-limiting example and is described with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0039] [Figure 1] FIG. 1 is a perspective view of an aerosol generating device according to the present invention. [Diagram 2] FIG. 2 is a perspective view of an aerosol-generating substrate that can be used with the aerosol-generating device of FIG. [Diagram 3] FIG. 2 is a perspective view of a tobacco article that can be used with the aerosol generating device of FIG. [Figure 4] 4 is a perspective view of the mouthpiece of FIG. 3 attached to the housing of the aerosol generating device of FIG. 1. [Diagram 5] 2 is a cross-sectional view of FIG. 1 taken along plane V. [Figure 6] FIG. 6 is a cross-sectional view of FIG. 5 along plane VI. [Figure 7] FIG. 7 is a cross-sectional view similar to that of FIG. 6, showing a preferred embodiment of a heater portion of an aerosol-generating substrate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] Before the present invention is described, it is to be understood that the invention is not limited to the details of construction set forth in the following description, as it will be apparent to one skilled in the art having the benefit of this disclosure that the invention is capable of other embodiments and of being practiced or carried out in various ways.

[0041] As used herein, the term "aerosol generating device" or "device" may include a vaping device for delivering aerosol, including aerosol for vaping, to a user using a heater element, as described in more detail below. The device may be portable. "Portable" may refer to a device that is held and used by a user. The device may be adapted to generate a variable amount of aerosol (as opposed to a fixed amount of aerosol), for example, by activating the heater element for a variable amount of time, the generation of which may be controlled by a trigger. The trigger may be user-activated, such as a vaping button and / or an inhalation sensor. The inhalation sensor may be sensitive to inhalation intensity and duration to allow for providing a variable amount of vapor (to mimic the smoking effect of a conventional combustible smoking article, such as a cigarette, cigar, or pipe). The device may include a temperature regulation control to drive the temperature of the heater and / or heated aerosol generating material (aerosol precursor) to a specific target temperature and then maintain the temperature at that target temperature that allows for efficient generation of aerosol.

[0042] As used herein, the term "aerosol" may include a suspension of vaporizable material as one or more of solid particles, liquid droplets, and gas. The suspension may be in a gaseous state, including air. Aerosol herein may generally refer to / include a vapor. Aerosol may include one or more components of vaporizable material.

[0043] As used herein, the term "vaporizable material" or "precursor" may refer to a smokable material that may include, for example, nicotine or tobacco and an aerosol-forming agent. Tobacco may take the form of various materials, such as cut tobacco, granulated tobacco, tobacco leaf, and / or reconstituted tobacco. Suitable aerosol-forming agents include polyols (e.g., sorbitol, glycerol, and glycols, such as propylene glycol or triethylene glycol), non-polyols (e.g., 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 include at least one of a gelling agent, a binder, a stabilizer, and a humectant.

[0044] In the following description, "vertical" and / or "horizontal" may be defined with respect to the orientation of the device during normal use, i.e., in the user's mouth. For example, the horizontal orientation may be detected due to the particular shape of the mouthpiece that fits into the typical lips of a user. The top surface of the device may be detected by the light that falls on it, the shape of the mouthpiece, and the opening that forms the inlet.

[0045] Figure 1 shows an aerosol-generating device 10 according to the invention. The aerosol-generating device 10 is intended to operate with an aerosol-generating substrate 12, also indicated as a tobacco article 12, shown in more detail in Figure 2.

[0046] With reference to FIG. 2, the tobacco article 12 is, for example, a plate-like rectangular parallelepiped extending along the article axis X. The tobacco article 12 defines external dimensions L×W×D. In a typical example, the length L of the tobacco article 12 along the article axis X is substantially equal to 33 mm, while its width W and depth D are substantially equal to 12 mm and 1.2 mm, respectively. According to another example, the values ​​L, W and D can be selected, for example, within the range of ±40%. The tobacco article 12 is generally plate-like due to its depth D. The depth D, also considered as thickness, of the tobacco article 12 is formed by a pair of parallel walls 13A, 13B, hereinafter referred to as side walls 13A, 13B of the substrate, and the width W of the substrate is formed by a pair of parallel walls 14A, 14B, hereinafter referred to as wide walls 14A, 14B of the substrate. According to other embodiments of the present invention, the tobacco article 12 can have any other suitable shape and / or external dimensions. For example, the tobacco article 12 can have a circular, oval, square, or rectangular cross-section. The tobacco article 12 can, for example, represent a stick having a shape similar to that of a conventional cigarette.

[0047] The tobacco article 12 comprises a heater portion 15, also denoted as substrate portion 15, and a gripping portion 16, also denoted as mouthpiece portion 16, arranged along an article axis X. The article axis X may be considered as the substrate axis X. The substrate portion 15 may, for example, be slightly longer than the gripping portion 16. For example, the length L2 of the substrate portion 15 along the article axis X may be substantially equal to 18 mm, and the length L1 of the gripping portion 16 along the article axis X may be substantially equal to 15 mm. The substrate portion 15 defines an abutting end 18 or a free end 18 of the tobacco article 12. The gripping portion 16 defines a mouth end 20 of the substrate 12. The substrate portion 15 and the gripping portion 16 may be secured to each other by a unique wrapper extending around the article axis X. In other embodiments, the portions 15, 16 may be wrapped by different wrappers and secured to each other by any other suitable means. The or each wrapper may, for example, comprise paper and / or nonwoven and / or aluminum. The or each wrapper may be porous or air impermeable. The or each wrapper forms a plurality of air flow channels that extend into the interior of the tobacco article 12 between the free end 18 and the mouth end 20.

[0048] The substrate portion 15 is intended to be heated by a heater (using a heating chamber in this example) and comprises a solid vaporizable material as defined above. As will be explained in more detail below, the gripping portion 16 is intended to be fully contained within the mouthpiece. According to another embodiment of the invention, a part of the gripping portion 16 forms itself a mouthpiece intended to contact the mouth and / or lips of a user. The gripping portion 16 may comprise a core 17, which may for example function as a filter. The core 17 may be, for example, a foam or a bundled strand or fiber. The core 17 may be formed into a stable shape by an extrusion and / or rolling process. The tobacco article 12 may be molded to provide one or more air flow channels. In the particular example of FIG. 2, the gripping portion 16 defines a number of ventilation holes 22, for example arranged around the entire circumference of the gripping portion 16 along two axes perpendicular to the article axis X. In other words, according to this example, the ventilation holes 22 are located in each wall of the tobacco article 12, among the substrate side walls 13A, 13B and the substrate broad walls 14A, 14B. According to another example, the ventilation holes 22 are located only in the substrate broad walls 14A, 14B, or preferably only in one of the substrate broad walls 14A, 14B. In both examples, the ventilation holes 22 may be aligned perpendicular to the substrate axis on the corresponding wall or on each of the corresponding walls of the tobacco article 12 and may be spaced apart by the same distance. The ventilation holes 22 allow fresh air to enter the interior of the tobacco article 12 to achieve a particular vaping effect / taste effect.

[0049] Referring again to Fig. 1, the aerosol generating device 10 comprises a device body 30 extending along a device axis Y and forming at least one outer wall 40 of the device 10. The device body 30 comprises a mouthpiece 32 and a housing 34 arranged successively along the device axis Y. According to the example of Fig. 1, the mouthpiece 32 and the housing 34 form two different parts. In particular, according to this example, the mouthpiece 32 is designed to be fixed to or accommodated in an insertion opening 36 formed in one of the ends of the housing 34. This opening 36 extends perpendicular to the device axis Y.

[0050] In each cross section, the housing 34 may for example form a substantially rectangular shape with rounded edges. In this case, the housing 34 together with the mouthpiece 32 may form at least four outer walls 40. According to other embodiments, the housing 34 may have a round cross-sectional shape. In this case, the housing 34 together with the mouthpiece 32 may form only one outer wall 40. The housing 34 may be sealed at the end opposite the insertion opening 36 that receives the mouthpiece 32. The housing 34 may be formed from a single piece or several assembled pieces made of any suitable material, such as aluminum or plastic. In some embodiments, the material of the housing 34 may be a thermally conductive material. In some other embodiments, the material may be a thermally insulating material. In some embodiments, the housing 34 may form one or more openings in the corresponding parts of the device outer wall 40, suitable for arranging control and / or visual elements. For example, such elements may include control buttons, touch panels, screens, LEDs, etc. 1, housing 34 forms a slotted opening 42 that receives, for example, an LED that indicates at least an on state of device 10. The LED can also indicate, for example, a low battery condition, an error condition, etc.

[0051] The housing 34 defines the boundaries of an interior space of the device 10, which contains various elements designed to perform different functions of the device 10. The interior space may contain, for example, a battery for powering the device 10, a retaining structure (not shown), a heating chamber for heating the tobacco article 12, and a heater comprising at least two heating elements (not shown), such as, for example, a heating plate for heating the heating chamber. The interior space may also contain a controller for controlling the operation of the heater. The heating chamber defines a chamber axis that may correspond to the device axis Y and / or the article axis X. The heating chamber extends along the chamber axis. In some embodiments, the housing 34 may further include at least one temperature sensor. The temperature sensor may generate temperature measurements, for example, of the temperature of the heater, and / or the temperature of the tobacco article 12, and / or the temperature of the aerosol generated by the tobacco article 12. The tobacco article 12, and in particular the gripping portion 16, may be maintained outside the heating chamber by a retaining structure, which is further described in Figures 5-6.

[0052] FIG. 3 shows the mouthpiece 32 in more detail. With reference to this FIG. 3, the mouthpiece 32 is bounded by an inner surface 56 intended to face the insertion opening 36 when the mouthpiece 32 is assembled to the housing 34, and an outer surface 57 intended to form together with the housing 34 at least one outer wall 40 of the device 10 (as shown in FIG. 1). The outer boundary 59 of the inner surface 56 is designed to fit closely against a portion of the inner boundary of the insertion opening 36 to fix the mouthpiece 32 inside the insertion opening 36 (as shown in FIG. 1). The outer surface 57 has a shape suitable for contacting the mouth and / or lips of the user. Each side of the outer surface 57 can be formed as an extension of the corresponding side of the housing so as to form a substantially continuous outer wall 40 of the device 10. In particular, in this case, a discontinuity may be formed in the transition area between the mouthpiece 32 and the housing 34.

[0053] The mouthpiece 32 is traversed between the notch 62 and the outlet 64 by a through hole 60 extending along the device axis Y. In particular, the through hole 60 is designed to accommodate the mouthpiece portion 16 of the aerosol-generating substrate 12 such that the article axis X coincides with and is aligned with the device axis Y (as shown in FIG. 2). The through hole 60 therefore has the same cross-sectional shape as the tobacco article 12 and defines an internal dimension that is slightly larger than the external dimension of the gripping portion 16 of the tobacco article 12. In particular, in the illustrated example, the through hole 60 defines a rectangular cross-section so that it can accommodate the gripping portion 16 of the tobacco article 12 shown in FIG. 2. In some embodiments, the through hole 60 may have variable cross-sectional dimensions. For example, the through hole 60 may have a cross-sectional dimension (particularly a width) that gradually decreases from the notch 62 towards the outlet 64. In addition, the through hole 60 and the mouthpiece portion 16 of the aerosol-generating substrate 12 may have the same length when measured along the device axis Y and the article axis X, respectively. According to another embodiment, the length of the gripping portion 16 of the tobacco article 12 can be less than the length of the through-hole 60 such that the mouth end 20 of the tobacco article 12 is flush with the outlet port 64 .

[0054] The notch 62 corresponds to a cavity or channel formed in both the inner surface 56 and the outer surface 57 of the mouthpiece 32. This cavity may be formed by a first opening extending from the boundary 59 of the inner surface 56 on one side of this through hole 60 to the through hole 60, and a second opening extending from the boundary to the outer surface 57 according to a percentage d% of the length of the mouthpiece 32 measured along the device axis Y. The value d% may be less than 25%, advantageously less than 10%, and even more advantageously less than 5%. Thus, when the mouthpiece 32 is inserted into the insertion opening 36, the notch 62 forms an opening 66 forming an inlet 66, as shown in FIG. 4. In other words, the inlet 66 is formed on the outer wall 40 of the device 10 in the transition area between the mouthpiece 32 and the housing 34.

[0055] In embodiments in which the tobacco article 12 includes ventilation holes 22 , at least some of these ventilation holes 22 are positioned opposite the inlet port 66 .

[0056] According to another embodiment of the invention (not shown), the inlet is formed in any other wall of the device 10. The inlet can be formed, for example, in the wall opposite the mouthpiece 32.

[0057] 5 shows in detail a portion of an aerosol generating device 10 according to the invention. The aerosol generating device 10 is similar or identical to the previous figures. The housing 34 is partially represented. The through cut plane V is away from and parallel to the device axis Y, as shown in FIG. 1.

[0058] The aerosol generating device 10 presents a chamber axis Z and a heating chamber 70 extending according to the chamber axis Z and configured to accommodate the substrate portion 15 of the tobacco article 12. In different embodiments of the invention, the heating chamber 70 may define a circular, elliptical, square or rectangular cross-sectional shape. In particular, this cross-sectional shape of the heating chamber 70 may be adapted to the cross-sectional shape of the tobacco article 12. In the illustrated example, the heating chamber 70 has a plate-like shape adapted to accommodate a plate-like tobacco article 12.

[0059] The heating chamber 70 comprises a heater comprising at least one heating plate 72. As will be explained in more detail below, the device 10 allows the substrate portion 15 to be held in the heating chamber 70 in a non-contact manner relative to the heater. In the example of Figs. 5 and 6, the heater of the heating chamber 70 comprises two heating plates 72 parallel to the substrate portion 15 and the chamber axis Z. The heating plates 72 may for example be at the same distance from the substrate portion 15, the distance being measured perpendicular to the chamber axis Z. The distance may be constant along the substrate portion 15 and / or the chamber axis Z. In the following description, the characteristics are defined in relation to one heating plate. Nevertheless, these characteristics may apply to each heating plate. According to other embodiments of the invention, the heater may take any other suitable shape or form. For example, if the tobacco article 12 has a circular or elliptical cross-sectional shape, the heater may comprise a cylindrical element extending in a non-contact manner around the substrate portion 15 of the tobacco article 12. In this case, the cylindrical elements are designed to be spaced apart from the substrate portion 15, for example at the same distance.

[0060] The aerosol generating device 10 includes a retaining structure 74 configured to engage the gripping portion 16 of the tobacco article 12 to retain the substrate portion 15 of the tobacco article 12 in the heating chamber 70 at a distance from the heater and, in the illustrated example, from the heating plate 72. The retaining structure 74 serves as the only retaining member. The distance is adapted to ensure convective heat transfer from the heater to the substrate portion 15. Air at the separation interface between the heater and the substrate portion 15 transfers the heat mass. It can be seen that the retaining structures 74, also considered as holding structures, are arranged outside the heating chamber 70. They may be separate and distinct. They are at a distance from each other along the chamber axis Z.

[0061] The heating chamber 70 defines an open end 76 that can be used to insert the substrate portion 15 of the tobacco article 12 into the heating chamber 70. The open end 76 forms an entrance having a larger cross section than the substrate portion 15. At the opposite side, the heating chamber 70 may present a closed end. The heating chamber 70 may then form a closed pocket. The heating chamber 70 may comprise a closed bottom opposite the open end 76. The free end 18 of the substrate portion 15 may face the closed bottom relative to the chamber axis Z.

[0062] The distance may be measured relative to one / any axis perpendicular to the chamber axis. The distance may be measured perpendicular to the inner surface of the heater plate 72 and / or perpendicular to the substrate portion 15.

[0063] The retaining structure 74 is disposed adjacent to and / or facing the open end 76 of the heating chamber 70. The retaining structure 74 may physically abut the open end 76 along the chamber axis Z or may be spaced therefrom.

[0064] The retaining structure 74 defines a receiving cavity 78 configured to extend along the chamber axis Z. The receiving cavity 78 is intended to receive and hold the gripping portion 16 of the tobacco article along the chamber axis Z. In the example of FIG. 5, the retaining structure 74 is formed by the mouthpiece 32, and the receiving cavity 78 corresponds to the through hole 60 of the mouthpiece 32. The inner surface 56 may be in physical contact with the gripping portion 16. The inner surface 56 may generally be an orientation means and / or a gripping means. The means are configured to set the orientation and / or location of the tobacco article 12. The inner surface 56 comprises a complementary surface to the gripping portion 16, for example to form a nested interface. Thereby, the substrate portion 15 is maintained in a predetermined position within the heating chamber 70 during operation. The receiving cavity 78 defines an opening 80, and a flow channel 60 extends from the heating chamber 70 through the receiving cavity 78 and the opening.

[0065] As a further option, the retaining structure 74 may be separate from the mouthpiece 32 and removable from the housing 34 of the device. For example, the retaining structure 74 may be designed to be located between the mouthpiece 32 and the heating chamber 70. The retaining structure 74 may comprise fastening means cooperating with the housing 34. These fastening means may be reversible fastening means. Illustratively, the outer surface 57 forms the fastening means. The outer surface 57 may conform to the inner surface of the housing 34. The outer surface 57 may fit snugly into the inner space of the housing 34, thereby providing a rigid assembly.

[0066] The retaining structure 74 is configured to engage the gripping portion 16 when it is removed from the housing 34 of the device 10. The gripping portion 16 is intended to be inserted into the retaining structure 74. The gripping portion 16 has an outer surface that mates with and is complementary to the inner surface 56. The inner surface may form a sealing means. The interface between the gripping portion 16 and the inner surface 56 may be airtight.

[0067] In the assembled state, the retaining structure 74 is configured to maintain the substrate portion 16 of the tobacco article at the same distance from the heater, and in the illustrated example, from each heating plate 72, within the heating chamber 70. The heating chamber 70 preferably has no physical contact with the substrate portion, and in particular with the free end 18 of the substrate portion 15. The heating chamber is configured such that the tobacco article 12 is mounted in a cantilever fashion. In the disassembled state, the retaining structure 74 is configured to maintain the substrate portion 16 of the tobacco article at a distance from each heating plate within the heating chamber.

[0068] Figure 6 is a through cut view taken through plane VI shown in Figure 5. The through cut view is perpendicular to the chamber axis Z. Through cut plane VI traverses the heating chamber 70 and thus also the heating plate 72 and the chamber axis Z. In addition, through cut plane VI intersects the substrate portion 15 of the tobacco product 12, thereby exposing interior features of the aerosol generation device 10. A retaining structure 78 is in the background of this drawing.

[0069] In the example of FIG. 6, the tobacco article 12 presents a rectangular cross-section. The tobacco article is generally plate-shaped. The tobacco article comprises two parallel main surfaces. The main surfaces may comprise or correspond to the substrate broad walls 14A and 14B. The substrate broad walls 14A and 14B are in the heating chamber 70. Each of the substrate broad walls 14A and 14B faces one of the heating plates 72. Each of the heating plates 72 may comprise an inner surface 84 or an inwardly facing surface that faces one of the substrate broad walls 14A and 14B. Each inner surface 84 is therefore associated with one of the substrate broad walls 14A, 14B. The heating plates 72 are identical. They may be symmetrical.

[0070] The retaining structure 74 of the aerosol generating device 10 is configured to maintain at least one distance G, also indicated as gap G, between the inner surface 84 and the associated wall 14A, 14B. The retaining structure 74 is configured to maintain the substrate portion 15 at a distance G from each heating plate 72 in the heating chamber 70. Preferably, the retaining structure 74 maintains the substrate portion 15 at the same distance G from each heating plate 72 in the heating chamber 70. The following description focuses on one distance G between the wall 14A, 14B of the substrate and the associated inner surface 84 of the device 10. However, the following features are applicable to each of the distances G of the device 10. One side, for example the upper or lower side with respect to a vertical direction (not illustrated), is described. Thus, the heating chamber 70 includes a convection space 82. The convection space 82 defines a separation between the substrate portion 15 and the heating plate 72. The convection space 82 may be free space. The convection space is configured to ensure convective heat transfer from the heating plate 72 to the substrate portion 15 of the tobacco article 12 .

[0071] The thickness of the convection space 82 may correspond to a distance G. The distance G may be defined according to an axis perpendicular to the chamber axis Z, for example, an axis perpendicular to the inner surface 84 and / or the substrate broad walls 14A, 14B.

[0072] With respect to the lateral direction T, the heating plate 72 is wider than the substrate portion 15. The lateral direction T may correspond to a horizontal direction. The heating chamber 70 comprises two heating plates 72 facing each other, at least when the tobacco article 12 is removed. The heating plates 72 generally face towards each other. With respect to the lateral direction T, the distance G may be constant along the aerosol substrate 12. The distance G may be equal on both walls 14A, 14B.

[0073] The heating chamber 70 includes a loop 86, for example an inner loop 86. The loop can be a ring, for example a rectangular ring. The loop 86 can encircle the chamber axis Z. The loop can be a loop of free space 86. The substrate portion 15 can be within and surrounded by the free loop 86. The loop 86 can be a free or empty space, through which convection heating occurs, for example towards the center. This empty space allows heat transfer from the heating plate 72 to the substrate portion 15. The heating is then more uniform.

[0074] Of course, if the tobacco article 12 has a cross-sectional shape different than that shown in FIG. 6, the convection space 82 and loops 86 may be defined in a similar manner.

[0075] As can be seen in FIG. 7, the heater portion 15 of the aerosol-generating substrate 12 may, for example, have the shape of a flat plate with grooves on both opposing sides.

[0076] The scope of protection is defined by the following claims.

Claims

1. An aerosol generating device (10) configured to operate with a tobacco article (12) comprising a substrate portion (15) and a gripping portion (16) arranged successively along an article axis (X), comprising: a heating chamber (70) extending according to a chamber axis (Z) and configured to accommodate said substrate portion (15) of said tobacco article (12), said heating chamber (70) comprising a heater extending along said chamber axis (Z); a retaining structure (74) configured to engage the gripping portion (16) of the tobacco article (12) to maintain the substrate portion (15) of the tobacco article (12) at a distance (G) from the heater within the heating chamber (70); The aerosol generating device (10) includes a retaining structure (74) extending along the chamber axis (Z) and defining a storage cavity (78) configured to receive and hold the gripping portion (16) of the tobacco article (12) along the chamber axis (Z), the storage cavity (78) defining an opening (80), and a flow channel extending from the heating chamber (70) through the storage cavity (78) to the opening (80).

2. 2. The aerosol generating device (10) of claim 1, wherein the distance (G) is adapted to ensure convective heat transfer from the heater to the substrate portion (15) of the tobacco article (12).

3. 2. The aerosol generating device (10) according to claim 1, wherein the distance (G) is formed along an axis perpendicular to the chamber axis (Z).

4. The aerosol generating device (10) according to claim 1, wherein the retaining structure (74) is disposed outside the heating chamber (70).

5. - the heating chamber (70) defines an open end (76) usable for inserting the substrate portion (15) of the tobacco article (12) into the heating chamber (70); - The aerosol generating device (10) of claim 1, wherein the retaining structure (74) is positioned adjacent to or facing the open end (76) of the heating chamber (70).

6. 2. The aerosol generating device (10) according to claim 1, wherein the retaining structure (74) is formed by a mouthpiece (32).

7. The aerosol generating device (10) according to claim 1, wherein the retaining structure (74) is removable from the housing (34) of the aerosol generating device (10).

8. 8. The aerosol generating device (10) of claim 7, wherein the retaining structure (74) is configured to engage with the grip portion (16) of the tobacco article (12) when the aerosol generating device (10) is removed from the housing (34).

9. 2. The aerosol generating device (10) of claim 1, wherein the tobacco article (12) is a plate-shaped tobacco article (12) and the heater is a heating plate (72), preferably comprising two heating plates (72) facing each other.

10. 10. The aerosol generating device (10) of claim 9, wherein the maintaining structure (74) is configured to maintain the substrate portion (15) of the tobacco article (12) at a certain distance (G) from each heating plate (72) within the heating chamber (70).

11. The aerosol generating device (10) of claim 10, wherein the maintaining structure (74) is configured to maintain the substrate portion (15) of the tobacco article (12) at the same distance (G) from each heating plate (72) within the heating chamber (70).

12. 2. The aerosol generating device (10) of claim 1, wherein the heating chamber (70) encloses a loop-shaped free space (86) configured to surround the substrate portion (15) of the tobacco article (12).

13. 13. The aerosol generating device (10) according to any one of claims 1 to 12, wherein the heating chamber (70) is configured to be out of contact with the free end (18) of the substrate portion (15).

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