Aerosol generation device, and heating chamber therefor

Abstract

To provide an improved aerosol generation device, and an improved heating chamber therefor.SOLUTION: An aerosol generation device 100 has a heating chamber 108 for receiving a substrate carrier 114 containing an aerosol substrate 128. The heating chamber includes: a first open end 110; a base 112; and a side wall 126 between the open end and the base. The base is connected to the side wall and provides structural support to the side wall. The side wall has a first thickness and the base has a second thickness greater than the first thickness.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to aerosol generating devices and heating chambers therefor. The disclosure is particularly applicable to portable aerosol generating devices that may be self-contained and low-temperature. Such devices can heat tobacco or other suitable materials by conduction, convection, and / or radiation, rather than by combustion, to generate an aerosol for inhalation. [Background technology]

[0002] 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 assisting regular smokers who wish to quit smoking traditional tobacco products such as cigarettes, cigars, cigarillos, and rolling tobacco. A variety of devices and systems are available that heat or warm an aerosolizable substance, as opposed to burning tobacco in traditional tobacco products.

[0003] A commonly available risk reduction or risk modification device is the heated substrate aerosol generator or heat-not-burn device. This type of device generates an aerosol or vapor by heating an aerosol substrate, typically comprising moist tobacco or other suitable aerosolizable material, to temperatures typically ranging from 150°C to 300°C. By heating rather than burning or combusting the aerosol substrate, an aerosol is released that contains the ingredients desired by the user but without the toxic and carcinogenic by-products of combustion and burning. Furthermore, aerosols produced by heating tobacco or other aerosolizable material typically do not contain the burnt or bitter taste that can result from combustion and burning, which can be unpleasant to users, and therefore the substrate does not require sugars and other additives typically added to such materials to make the smoke and / or vapor more palatable to the user.

[0004] In general terms, it is desirable to rapidly heat the aerosol substrate to a temperature at which the aerosol can be released from the aerosol substrate, and to maintain the aerosol substrate at that temperature. It will be apparent that only if there is airflow past the aerosol substrate will the aerosol be released from the aerosol substrate and delivered to the user. Summary of the Invention [Problem to be solved by the invention]

[0005] Because this type of aerosol generating device is a portable device, energy consumption is an important design consideration. The present invention aims to address problems with existing devices and to provide an improved aerosol generating device and heating chamber therefor. [Means for solving the problem]

[0006] According to a first aspect of the present disclosure, there is provided a heating chamber for an aerosol generating device, the heating chamber comprising: a first open end; A base and a sidewall between the open end and the base; the base is connected to the sidewall and provides structural support to the sidewall; The sidewall has a first thickness and the base has a second thickness greater than the first thickness.

[0007] Optionally, the sidewalls and base are formed from the same material, preferably the material is metal, more preferably the sidewalls and base are stainless steel, even more preferably stainless steel. The steel is a 300 series stainless steel, and even more preferably is selected from the group including 304 stainless steel, 316 stainless steel, and 321 stainless steel.

[0008] Optionally, the base and sidewall are formed as a single element, preferably forming a cup-shaped element.

[0009] Optionally, the first thickness is less than or equal to 100 μm.

[0010] Optionally, the second thickness is between 200 μm and 500 μm.

[0011] Optionally, the base seals a second end of the sidewall opposite the open end, and preferably the sidewall extends around the entire periphery of the base.

[0012] Optionally, the heating chamber includes a flange portion attached to the open end, the flange portion extending radially outward at the open end of the heating chamber.

[0013] Optionally, the flange portion extends around the entire periphery of the heating chamber.

[0014] Optionally, the flange portion extends diagonally away from the sidewall.

[0015] Optionally, the flange portion comprises a first material and the sidewall comprises a second material, the first material having a lower thermal conductivity than the second material.

[0016] Optionally, the sidewall comprises a material having a thermal conductivity of 50 W / mK or less.

[0017] Optionally, the heating chamber further comprises a plurality of protrusions formed on an interior surface of the sidewall.

[0018] Optionally, the protrusion is formed by recessing the exterior surface of the sidewall.

[0019] Optionally, the heating chamber further comprises a platform on an interior surface of the base.

[0020] Optionally, the platform is formed by a depression in the outer surface of the base.

[0021] Optionally, the heating chamber is a deep-drawn product.

[0022] According to a second aspect of the present disclosure, there is provided an aerosol generating device, the aerosol generating device comprising: Power supply and a heating chamber as described above; a heater configured to supply heat to the heating chamber; and a control circuit configured to control the supply of power from the power source to the heater.

[0023] Optionally, the heater is provided on an outer surface of the sidewall.

[0024] Optionally, the heater is located adjacent to the exterior surface of the sidewall.

[0025] Optionally, the heating chamber is removable from the aerosol generating device. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a schematic perspective view of an aerosol generating device according to a first embodiment of the present disclosure. FIG. [Figure 2] FIG. 2 is a schematic cross-sectional side view of the aerosol generating device of FIG. 1. [Figure 2a] 2. FIG. 3 is a schematic cross-sectional view of the aerosol generating device of FIG. 1 taken along line XX shown in FIG. 2. [Figure 3] 2 is a schematic perspective view of the aerosol generating device of FIG. 1, in which a substrate carrier of an aerosol substrate is being loaded into the aerosol generating device. [Figure 4] 2 is a schematic cross-sectional side view of the aerosol generating device of FIG. 1, the aerosol generating device being loaded with a substrate carrier of an aerosol substrate. [Figure 5] 2 is a schematic perspective view of the aerosol generating device of FIG. 1, in which the aerosol generating device is loaded with a substrate carrier of an aerosol substrate. [Figure 6] 2 is a schematic cross-sectional side view of the aerosol generating device of FIG. 1, in which the aerosol generating device is loaded with a substrate carrier of an aerosol substrate. [Figure 6a]FIG. 7 is a detailed cross-sectional view of a portion of FIG. 6 highlighting the interaction between the substrate carrier and protrusions in the heating chamber and the corresponding effect on the air flow path. [Figure 7] FIG. 1 is a plan view of the heater separated from the heating chamber. [Figure 8] FIG. 10 is a schematic cross-sectional side view of an aerosol generating device according to a second embodiment of the present disclosure, having an alternative airflow arrangement. [Figure 9] A schematic cross-sectional side view of an aerosol generating device according to a third embodiment of the present disclosure, having a heating chamber with a base formed as a separate part from a portion of the side wall. [Figure 9a] FIG. 10 is a perspective view from above of a heating chamber of an aerosol generating device according to a third embodiment of the present disclosure. [Figure 9b] FIG. 10 is a perspective view from below of a heating chamber of an aerosol generating device according to a third embodiment of the present disclosure. [Figure 10] FIG. 10 is a schematic perspective view of an aerosol generating device according to a fourth embodiment of the present disclosure, having a flangeless heating chamber. [Figure 10a] FIG. 10 is a perspective view from above of a heating chamber of an aerosol generating device according to a fourth embodiment of the present disclosure. [Figure 10b] FIG. 10 is a perspective view from below of a heating chamber of an aerosol generating device according to a fourth embodiment of the present disclosure. [Figure 11] FIG. 10 is a schematic perspective view of an aerosol generating device according to a fifth embodiment of the present disclosure, having a heating chamber without protrusions on its sidewalls. [Figure 11a] FIG. 10 is a perspective view from above of a heating chamber of an aerosol generating device according to a fifth embodiment of the present disclosure. [Figure 11b] FIG. 10 is a perspective view from below of a heating chamber of an aerosol generating device according to a fifth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0027] First embodiment 1 and 2, according to a first embodiment of the present disclosure, an aerosol generating device 100 comprises an outer casing 102 that houses the various components of the aerosol generating device 100. In the first embodiment, the outer casing 102 is tubular. More specifically, the outer casing is cylindrical. It should be noted that the outer casing 102 need not have a tubular or cylindrical shape, but can be any shape as long as it is sized to fit the components described in the various embodiments herein. The outer casing 102 can be formed of any suitable material, or indeed layers of material. For example, a metal inner layer can be surrounded by a plastic outer layer. This allows the outer casing 102 to be comfortable for a user to hold. Any heat that escapes from the aerosol generating device 100 is distributed around the outer casing 102 by the metal layer, thereby preventing hot spots. While preventing potting, the plastic layer softens the feel of the outer casing 102. Additionally, the plastic layer can help protect the metal layer from tarnishing or scratches, improving the long-term appearance of the aerosol generating device 100.

[0028] The first end 104 of the aerosol generating device 100 shown at the bottom of each of Figures 1-6 is described for convenience as the bottom, base, or lower end of the aerosol generating device 100. The second end 106 of the aerosol generating device 100 shown at the top of each of Figures 1-6 is described as the top or upper end of the aerosol generating device 100. In the first embodiment, the first end 104 is the lower end of the outer casing 102. During use, a user typically orients the aerosol generating device 100 with the first end 104 facing downward and / or distal to the user's mouth and the second end 106 facing upward and / or proximal to the user's mouth.

[0029] As shown, the aerosol generation device 100 has a pair of washers 107a, 107b held in place at the second end 106 by an interference fit with the interior portion of the outer casing 102 (only the upper washer 107a is visible in Figures 1, 3, and 5). In some embodiments, the outer casing 102 is crimped or bent around the upper washer 107a at the second end 106 of the aerosol generation device 100 to hold the washers 107a, 107b in place. The other washer 107b (i.e., the washer furthest from the second end 106 of the aerosol generation device 100) rests on a shoulder or annular ridge 109 of the outer casing 102, thereby preventing the lower washer 107b from seating more than a predetermined distance from the second end 106 of the aerosol generation device 100. Washers 107a, 107b are made from a thermally insulating material, which in this embodiment is, for example, polyetheretherketone (PEEK), suitable for use in medical devices.

[0030] The aerosol generation device 100 has a heating chamber 108 located toward the second end 106 of the aerosol generation device 100. The heating chamber 108 is open toward the second end 106 of the aerosol generation device 100. In other words, the heating chamber 108 has a first open end 110 toward the second end 106 of the aerosol generation device 100. The heating chamber 108 is held in spaced relation from the interior surface of the outer casing 102 by fitting through central openings in washers 107 a and 107 b. In this configuration, the heating chamber 108 is held in a generally coaxial configuration with the outer casing 102. The heating chamber 108 is suspended by a flange 138 of the heating chamber 108, which is located at the open end 110 of the heating chamber 108 and is captured between a pair of washers 107 a and 107 b. This means that heat conduction from the heating chamber 108 to the outer casing 102 generally passes through the washers 107 a, 107 b and is thereby limited by the insulating properties of the washers 107 a, 107 b. Because there is an air gap surrounding the heating chamber 108, heat transfer from the heating chamber 108 to the outer casing 102 other than through the washers 107 a, 107 b is also reduced. In the illustrated embodiment, the flange 138 extends outward from the sidewall 126 of the heating chamber 108 a distance of about 1 mm, forming an annular structure.

[0031] To further improve the thermal insulation of the heating chamber 108, the heating chamber 108 is also surrounded by an insulating material. In some embodiments, the insulating material is a fibrous or foam material, such as cotton wool. In the illustrated embodiment, the insulator comprises an insulating member 152 in the form of an insulating cup comprising a double-walled tube 154 and a base 156. In some embodiments, the insulating member 152 may comprise a pair of nested cups enclosing a cavity therebetween. The cavity 158 defined between the walls of the double-walled tube 154 can be filled with an insulating material, such as a fiber, foam, gel, or gas (e.g., at low pressure). In some cases, the cavity 158 may contain a vacuum. Advantageously, the vacuum required to achieve high thermal insulation is very thin, so the walls of the double-walled tube 154 surrounding the cavity 158 can be only 100 μm thick, and the total thickness (the two walls and the cavity 158 between them) can be only 1 mm. The base 156 is an insulating material such as silicone. Silicone is flexible, so the electrical connection 150 of the heater 124 can pass through the base 156, which forms a seal around the electrical connection 150.

[0032] As shown in FIGS. 1-6 , the aerosol generating device 100 may include an outer casing 102, a heating chamber 108, and an insulating member 152, as described in detail above. FIGS. 1-6 also show an elastically deformable member 160 positioned between the outwardly facing surface of the insulating sidewall 154 and the inner surface of the outer casing 102 to hold the insulating member 152 in place. The elastically deformable member 160 may provide sufficient friction to form an interference fit to maintain the insulating member 152 in place. The elastically deformable member 160 may be a gasket or O-ring or a closed loop of other material that conforms to the outwardly facing surface of the insulating sidewall 154 and the inner surface of the outer casing 102. The elastically deformable member 160 may be formed of an insulating material, such as silicone, to provide additional insulation between the insulating member 152 and the outer casing 102. This therefore reduces heat transferred to the outer casing 102, allowing a user to hold the outer casing 102 comfortably during use. An elastically deformable material is, for example, an elastic or rubber material that can be compressed and deformed but bounces back to its original shape.

[0033] As an alternative to this configuration, the insulating member 152 may be supported by struts extending between the insulating member 152 and the outer casing 102. The struts may provide additional rigidity to ensure that the heating chamber 108 is centered within the outer casing 102 or that the heating chamber is located at a set location. The struts may be designed to distribute heat evenly throughout the outer casing 102, preventing hot spots.

[0034] As yet a further alternative, the heating chamber 108 may be secured within the aerosol generating device 100 by a mating portion on the outer casing 102 for engaging the sidewall 126 at the open end 110 of the heating chamber 108. Because the open end 110 is exposed to the most cold air flow and therefore cools the fastest, attaching the heating chamber 108 to the outer casing 102 near the open end 110 allows heat to dissipate quickly to the environment and ensures a tight fit.

[0035] It should be noted that in some embodiments, the heating chamber 108 is removable from the aerosol generating device 100. Thus, the heating chamber 108 can be easily cleaned or replaced. In such embodiments, the heater 124 and electrical connections 150 may not be removable and may remain in place in the insulating member 152.

[0036] In a first embodiment, the base 112 of the heating chamber 108 is closed. That is, the heating chamber 108 is cup-shaped. In other embodiments, the base 112 of the heating chamber 108 has one or more holes or is perforated, so that the heating chamber 108 remains generally cup-shaped but is not closed at the base 112. In yet other embodiments, the base 112 is closed, but the sidewall 126 has one or more holes or is perforated in an area adjacent to the base 112, for example, between the heater 124 (or metal layer 144) and the base 112. The heating chamber 108 also has a sidewall 126 between the base 112 and the open end 110. The sidewall 126 and the base 112 are connected to one another. In the first embodiment, the sidewall 126 is tubular. More specifically, the sidewall is cylindrical. However, in other embodiments, the sidewall 126 has other suitable shapes, such as a tube having an elliptical or polygonal cross-section. Typically, the cross section is generally uniform over the length of the heating chamber 108 (not considering the protrusions 140), but in other embodiments the cross section may vary, for example, the cross section may decrease in size towards one end, such as a tapered or frustoconical tubular shape.

[0037] In the illustrated embodiment, the heating chamber 108 is unitary, i.e., the sidewall 126 and base 112 are formed from a single piece of material, for example, by a deep-drawing process. This can result in a stronger heating chamber 108 overall. In other examples, the base 112 and / or flange 138 may be formed as separate pieces and then attached to the sidewall 126. This can allow the flange 138 and / or base 112 to be formed from a different material than the material from which the sidewall 126 is made. The sidewall 126 itself is configured to be thin-walled. In some embodiments, the sidewall is at most 150 μm thick. Typically, the sidewall 126 is less than 100 μm thick, for example, about 90 μm thick, or even about 80 μm thick. In some cases, the sidewall 126 can be about 50 μm thick, but as the thickness decreases, the breakage rate in the manufacturing process increases. Overall, a range of 50µm to 100µm is usually adequate, with 70µm to 90µm being optimal. Manufacturing tolerances are around ±10µm, but the parameters provided are intended to be accurate to around ±5µm.

[0038] When the sidewall 126 is thin as defined above, the thermal characteristics of the heating chamber 108 change significantly. Because the sidewall 126 is so thin, heat transfer through it encounters negligible resistance, but heat transfer along the sidewall 126 (i.e., parallel to the central axis or around the circumference of the sidewall 126) has small channels along which conduction can occur. Therefore, heat generated by the heater 124 located on the outer surface of the heating chamber 108 remains localized near the heater 124 in a radially outward direction from the sidewall 126 at the open end, but quickly results in heating of the interior surface of the heating chamber 108. In addition, the thin sidewall 126 helps reduce the thermal mass of the heating chamber 108, thereby improving the overall efficiency of the aerosol generation device 100 because less energy is used to heat the sidewall 126.

[0039] The heating chamber 108, and specifically the sidewall 126 of the heating chamber 108, comprises a material having a thermal conductivity of 50 W / mK or less. In a first embodiment, the heating chamber 108 is a metal, preferably stainless steel. Stainless steel has a thermal conductivity of approximately 15-40 W / mK, with the exact value depending on the particular alloy. As a further example, 300 series stainless steel suitable for this application has a thermal conductivity of approximately 16 W / mK. Suitable examples include 304, 316, and 321 stainless steel, which are approved for medical use, have high strength, and have a thermal conductivity low enough to enable the localized heat described herein.

[0040] Materials with the recited levels of thermal conductivity reduce the ability of heat to be conducted away from the area where it is applied compared to materials with higher thermal conductivity, e.g., heat remains localized adjacent to the heater 124. Heat transfer to other parts of the aerosol-generating device 100 is inhibited, thereby improving heating efficiency by ensuring that only parts of the aerosol-generating device 100 that are intended to be heated are actually heated, and not parts that are not intended to be heated.

[0041] Metals are preferred materials because they are strong, malleable, and easy to mold and form. In addition, their thermal properties vary greatly from metal to metal and can be tailored as needed by careful alloying. In this application, "metal" refers to elemental (i.e., pure) metals as well as alloys of several metals or other elements, such as carbon.

[0042] Accordingly, the configuration of heating chamber 108 with thin sidewalls 126, along with the selection of a material having desirable thermal properties from which sidewalls 126 are formed, ensures that heat can be efficiently conducted through sidewalls 126 and into aerosol substrate 128. Advantageously, this also results in a reduction in the time required to raise the temperature from ambient to a temperature at which an aerosol can be released from aerosol substrate 128 following initial activation of the heater.

[0043] The heating chamber 108 is formed by deep drawing. This is an effective method of forming the heating chamber 108 and can be used to provide a very thin sidewall 126. The deep drawing process involves pressing a sheet metal blank with a punch tool into a forming die. Using a series of progressively smaller punch tools and dies, a tubular structure is formed, with a base at one end and a tube that is deeper than it is across the tube (the term "deep drawn" comes from the tube having a relatively greater length than width). As a result of being formed in this manner, the sidewalls of the tube formed in this manner are the same thickness as the original sheet metal. Similarly, the base formed in this manner is the same thickness as the starting sheet metal blank. A flange can be formed at the end of the tube by leaving a peripheral edge of the original sheet metal blank extending outward at the end opposite the base of the tubular wall (i.e., by starting with more material in the blank than is necessary to form the tube and base). Alternatively, the flanges may be formed later in a separate process involving one or more of cutting, bending, rolling, swaging, and the like.

[0044] As noted, the tubular sidewall 126 of the first embodiment is thinner than the base 112. This can be achieved by first deep drawing the tubular sidewall 126 and then ironing the wall. Ironing refers to heating the tubular sidewall 126 and drawing it, so that the tubular sidewall becomes thinner in the process. In this manner, the tubular sidewall 126 can be made to the dimensions described herein.

[0045] The thin sidewall 126 can be fragile. This can be mitigated by providing additional structural support to the sidewall 126 and by forming the sidewall 126 into a tubular, preferably cylindrical, shape. In some cases, the additional structural support is provided as a separate feature, but it should be noted that the flange 138 and base 112 also provide a degree of structural support. Considering the base 112 first, it should be noted that while open-ended tubes are generally prone to collapse, the inclusion of the base 112 in the heating chamber 108 of the present disclosure provides additional support. It should be noted that in the illustrated embodiment, the base 112 is thicker than the sidewall 126, e.g., two to ten times thicker than the sidewall 126. In some cases, this may result in a base 112 having a thickness of 200 μm to 500 μm, e.g., approximately 400 μm. The base 112 also has the additional purpose of preventing the substrate carrier 114 from being excessively inserted into the aerosol generation device 100. Increasing the thickness of the base 112 helps prevent damage to the heating chamber 108 if a user inadvertently applies too much force when inserting the substrate carrier 114. Similarly, when a user cleans the heating chamber 108, the user may typically insert an object, such as an elongated brush, through the open end 110 of the heating chamber 108. This means that when the elongated object strikes the base 112, the user is likely to exert more force against the base 112 than against the sidewalls 126 of the heating chamber 108. Therefore, the thickness of the base 112 relative to the sidewalls 126 can help prevent damage to the heating chamber 108 during cleaning. In other embodiments, the base 112 has the same thickness as the sidewalls 126, which provides some of the advantageous effects described above.

[0046] The flange 138 extends outward from the sidewall 126 and has an annular shape that extends completely around the periphery of the sidewall 126 at the open end 110 of the heating chamber 108. The flange 138 resists bending and shear forces at the sidewall 126. For example, lateral deformation of the tube defined by the sidewall 126 would likely require the flange 138 to buckle. While the flange 138 is shown extending generally perpendicularly from the sidewall 126, it should be noted that the flange 138 could extend obliquely from the sidewall 126, for example, forming a funnel shape with the sidewall 126, while retaining the advantageous characteristics described above. In some embodiments, instead of being annular, the flange 138 is located only partially around the periphery of the sidewall 126. In the illustrated embodiment, the flange 138 is the same thickness as the sidewall 126; however, in other embodiments, the flange 138 is thicker than the sidewall 126 to improve resistance to deformation. Increased thickness in certain areas for strength is balanced against the increased thermal mass introduced so that the aerosol generating device 100 as a whole remains strong yet efficient.

[0047] The interior surface of the sidewall 126 is formed with a plurality of protrusions 140. The width of the protrusions 140 around the periphery of the sidewall 126 is small compared to their length parallel to the central axis of the sidewall 126 (i.e., generally in the direction from the base 112 to the open end 110 of the heating chamber 108). In this example, there are four protrusions 140. As will become apparent from the discussion below, four is typically a suitable number of protrusions 140 to hold the substrate carrier 114 in a central position within the heating chamber 108. In some embodiments, for example, three protrusions spaced (evenly) about 120 degrees around the circumference of the sidewall 126 may be sufficient. The protrusions 140 have various purposes, and the exact shape of the protrusions 140 (and corresponding recesses on the exterior surface of the sidewall 126) is selected based on the desired effect. In any event, the protrusions 140 may be referred to as engaging elements because they extend toward and engage the substrate carrier 114. Indeed, the terms “protrusion” and “engagement element” are used interchangeably herein. Similarly, when protrusion 140 is provided by externally compressing sidewall 126, such as by hydroforming or pressure molding, the term “recess” is used interchangeably with the terms “protrusion” and “engagement element.” Forming protrusion 140 by recessing sidewall 126 has the advantage that the protrusion is integral with sidewall 126 and therefore has minimal impact on heat flow. Additionally, protrusion 140 does not add any thermal mass, as would be the case if an additional element were added to the interior surface of sidewall 126 of heating chamber 108. In fact, as a result of forming protrusion 140 by recessing sidewall 126, the thickness of sidewall 126 remains substantially constant circumferentially and / or axially, even at the locations where the protrusion is provided. Finally, recessing the sidewall as described increases the strength of sidewall 126 by introducing a portion that extends across sidewall 126, thereby providing resistance to bending of sidewall 126.

[0048] The heating chamber 108 is configured to accommodate a substrate carrier 114. Typically, the substrate carrier comprises an aerosol substrate 128, such as tobacco or another suitable aerosolizable material that can be heated to generate an aerosol for inhalation. In a first embodiment, the heating chamber 108 is sized to accommodate a dose of the aerosol substrate 128, for example, in the form of a substrate carrier 114, also known as a "consumable," as shown in FIGS. 3-6. However, this is not required, and in other embodiments, the heating chamber 108 is configured to accommodate other forms of aerosol substrate 128, such as loose or otherwise packaged tobacco.

[0049] The aerosol generating device 100 functions both by conducting heat from the surfaces of the protrusions 140 that engage the outer layer 132 of the substrate carrier 114, and by heating the air in the air gap between the interior surface of the sidewall 126 and the exterior surface of the substrate carrier 114. That is, when a user inhales on the aerosol generating device 100, there is convective heating of the aerosol substrate 128 as heated air is drawn through the aerosol substrate 128 (as explained in more detail below). The width and height (i.e., the distance each protrusion 140 extends into the heating chamber 128) determine the heat transfer rate. and the distance it extends) increases the surface area of ​​the sidewall 126 that transfers heat to the air, allowing the aerosol generating device 100 to reach an effective temperature more quickly.

[0050] When the substrate carrier 114 is inserted into the heating chamber 108, the protrusions 140 on the interior surface of the sidewall 126 extend toward and actually contact the substrate carrier 114 (see, e.g., FIG. 6 ), thereby causing the aerosol substrate 128 to also be heated by conduction through the outer layer 132 of the substrate carrier 114.

[0051] It will be apparent that in order to conduct heat into the aerosol substrate 128, the surfaces 145 of the protrusions 140 must interengage with the outer layer 132 of the substrate carrier 114. However, manufacturing tolerances may result in small variations in the diameter of the substrate carrier 114. Additionally, due to the relatively soft and compressible nature of the outer layer 132 of the substrate carrier 114 and the aerosol substrate 128 held therein, any damage or rough handling to the substrate carrier 114 may result in the outer layer 132 reducing in diameter or changing in shape to an oval or elliptical cross-section in the areas where it is intended to interengage with the surfaces 145 of the protrusions 140. Accordingly, any variation in the diameter of the substrate carrier 114 may result in reduced thermal engagement between the outer layer 132 of the substrate carrier 114 and the surfaces 145 of the protrusions 140, thereby adversely affecting heat conduction from the surfaces 145 of the protrusions 140 through the outer layer 132 of the substrate carrier 114 and into the aerosol substrate 128. To mitigate the effects of any variations in the diameter of the substrate carrier 114 due to manufacturing tolerances or damage, the protrusions 140 are preferably sized to extend sufficiently into the heating chamber 108 to cause compression of the substrate carrier 114, thereby ensuring an interference fit between the surface 145 of the protrusions 140 and the outer layer 132 of the substrate carrier 114. This compression of the outer layer 132 of the substrate carrier 114 may also cause longitudinal markings of the outer layer 132 of the substrate carrier 114 to provide a visual indication that the substrate carrier 114 has been used.

[0052] FIG. 6(a) shows an enlarged view of the heating chamber 108 and substrate carrier 114. As can be seen, arrow B indicates the air flow path that provides the convective heating described above. As noted above, the heating chamber 108 may be cup-shaped with a sealed, airtight base 112, meaning that airflow cannot pass through the sealed, airtight base 112 and must flow down the side of the substrate carrier 114 to enter the first end 134 of the substrate carrier. As noted above, the protrusions 140 extend a sufficient distance into the heating chamber 108 to contact at least the exterior surface of the substrate carrier 114 and typically cause at least some compression of the substrate carrier. As a result, the cross-sectional view of FIG. 6(a) penetrates the protrusions 140 on the left and right of the figure, so that there are no air gaps entirely along the heating chamber 108 within the plane of the figure. Instead, the air flow paths (arrows B) are shown as dashed lines in the region of the protrusions 140, indicating that the air flow paths are located in front of and behind the protrusions 140. Indeed, a comparison with Figure 2(a) shows that the air flow paths occupy four equally spaced gap regions between the four protrusions 140. Of course, in some situations there may be more or fewer than four protrusions 140, in which case the general point that the air flow paths exist in the gaps between the protrusions remains true.

[0053] Also highlighted in Figure 6(a) is the deformation of the outer surface of the substrate carrier 114 caused by the substrate carrier 114 being forced past the protrusions 140 as it is inserted into the heating chamber 108. As noted above, the distance that the protrusions 140 extend into the heating chamber can advantageously be selected to be large enough to cause any compression of the substrate carrier 114. This (sometimes permanent) deformation during heating can help provide stability to the substrate carrier 114 in the sense that the deformation of the outer layer 132 of the substrate carrier 114 creates a region of higher density of the aerosol substrate 128 near the first end 134 of the substrate carrier 114. In addition, the resulting deformation of the substrate carrier 114 can also help provide stability to the substrate carrier 114 in the sense that it creates a region of higher density of the aerosol substrate 128 near the first end 134 of the substrate carrier 114. The contoured outer surface of body 114 provides a gripping effect on the edge of the denser region of aerosol substrate 128 near first end 134 of substrate carrier 114. Overall, this reduces the likelihood that any loose aerosol substrate will fall off first end 134 of substrate carrier 114 and contaminate heating chamber 108. This is a useful effect because, as discussed above, heating aerosol substrate 128 causes aerosol substrate 128 to shrink, thereby increasing the likelihood that loose aerosol substrate 128 will fall off first end 134 of substrate carrier 114. This undesirable effect is mitigated by the deformation effect described.

[0054] To ensure that the protrusions 140 are in contact with the substrate carrier 114 (contact is necessary to cause conductive heating, compression, and deformation of the aerosol substrate), the manufacturing tolerances of each of the protrusions 140, the heating chamber 108, and the substrate carrier 114 are taken into account. For example, the inner diameter of the heating chamber 108 may be 7.6±0.1 mm, the substrate 114 carrier may have an outer diameter of 7.0±0.1 mm, and the protrusions 140 may have a manufacturing tolerance of ±0.1 mm. In this example, assuming the substrate carrier 114 is centrally mounted within the heating chamber 108 (i.e., leaving a uniform gap around the outside of the substrate carrier 114), the gap that each protrusion 140 must span to contact the substrate carrier 114 ranges from 0.2 mm to 0.4 mm. In other words, since each protrusion 140 spans a radial distance, the smallest possible value in this example is half the difference between the smallest possible diameter of the heating chamber 108 and the largest possible diameter of the substrate support 114, i.e., [(7.6 - 0.1) - (7.0 + 0.1)] / 2 = 0.2 mm. The upper limit of the range in this example is (for similar reasons) half the difference between the largest possible diameter of the heating chamber 108 and the smallest possible diameter of the substrate support 114, i.e., [(7.6 + 0.1) - (7.0 - 0.1)] / 2 = 0.4 mm. Clearly, to ensure that the protrusions 140 truly contact the substrate support, in this example, each protrusion must extend at least 0.4 mm into the heating chamber. However, this does not take into account manufacturing tolerances for the protrusions 140. If a 0.4 mm protrusion is desired, the range actually produced is 0.4 ± 0.1 mm, i.e., varying between 0.3 mm and 0.5 mm. Some of the protrusions will not span the maximum possible gap between the heating chamber 108 and the substrate carrier 114. Therefore, the protrusions 140 in this example should be fabricated with a nominal protrusion distance of 0.5 mm, resulting in a range of values ​​between 0.4 mm and 0.6 mm. This value is sufficient to ensure that the protrusions 140 always contact the substrate carrier.

[0055] Generally, the inner diameter of the heating chamber 108 is set to D±δ D , the outer diameter of the substrate support 114 is d±δ d, and the distance that the protrusion 140 extends into the heating chamber 108 is defined as L±δ L Written as follows, the distance that protrusion 140 is intended to extend into the heating chamber should be selected as follows:

number

[0056] Additionally, manufacturing tolerances may result in slight variations in the density of the aerosol substrate 128 within the substrate carrier 114. Such variations in the density of the aerosol substrate 128 may result in a simple Variations in the density of the aerosol substrate 128 may exist both axially and radially within a single substrate carrier 114 or between different substrate carriers 114 manufactured in the same batch. Accordingly, it will also be apparent that it is important that the density of the aerosol substrate 128 be relatively consistent to ensure relatively uniform heat conduction within the aerosol substrate 128 within a particular substrate carrier 114. To mitigate the effects of any inconsistencies in the density of the aerosol substrate 128, the protrusions 140 may be sized to extend sufficiently into the heating chamber 108 to cause compression of the aerosol substrate 128 within the substrate carrier 114, thereby improving heat conduction through the aerosol substrate 128 by eliminating air gaps. In the illustrated embodiment, a protrusion 140 extending approximately 0.4 mm into the heating chamber 108 is appropriate. In other examples, the distance that the protrusions 140 extend into the heating chamber 108 may be defined as a percentage of the distance across the heating chamber 108. For example, the protrusions 140 may extend a distance of 3% to 7%, such as about 5%, of the distance across the heating chamber 108. In another embodiment, the confined diameter circumscribed by the protrusions 140 within the heating chamber 108 is 6.0 mm to 6.8 mm, more preferably 6.2 mm to 6.5 mm, and especially 6.2 mm (±0.5 mm). Each of the plurality of protrusions 140 spans a radial distance of 0.2 mm to 0.8 mm, and most preferably 0.2 mm to 0.4 mm.

[0057] With respect to the protrusions / recesses 140, their width corresponds to the distance around the periphery of the sidewall 126. Similarly, their length extends perpendicular to their width and runs generally from the base 112 to the open end of the heating chamber 108 or to the flange 138, and their height corresponds to the distance the protrusion extends from the sidewall 126. Note that the space between adjacent protrusions 140, the sidewall 126, and the outer layer 132 of the substrate carrier 114 defines the area available for airflow. This has the effect that a smaller distance between adjacent protrusions 140 and / or the height of the protrusions 140 (i.e., the distance the protrusions 140 extend into the heating chamber 108) results in a user having to inhale harder to draw air through the aerosol generation device 100 (known as increased draw resistance). It will be apparent that it is the width of the protrusions 140 (assuming the protrusions 140 are in contact with the outer layer 132 of the substrate carrier 114) that determines the reduction in the airflow channel between the sidewall 126 and the substrate carrier 114. Conversely (again, assuming the protrusions 140 are in contact with the outer layer 132 of the substrate carrier 114), increasing the height of the protrusions 140 will compress the aerosol substrate more, thereby eliminating air gaps within the aerosol substrate 128, which also increases the draw resistance. These two parameters can be adjusted to provide a satisfactory draw resistance that is neither too low nor too high. The heating chamber 108 can be made larger to increase the airflow channel between the sidewall 126 and the substrate carrier 114, but there is a practical limit where the gap becomes too large and the heater 124 begins to become ineffective. Typically, a gap of 0.2 mm to 0.4 mm or 0.2 mm to 0.3 mm around the exterior surface of the substrate carrier 114 is a good compromise, allowing the retraction resistance to be fine-tuned within tolerances by varying the size of the protrusions 140. The air gap around the exterior of the substrate carrier 114 can also be varied by varying the number of protrusions 140. Any number of protrusions 140 (one or more) will provide at least some of the benefits described herein (increasing the heating area, providing compression, providing conductive heating of the aerosol substrate 128, adjusting the air gap, etc.).The minimum number that will reliably hold the substrate carrier 114 in central (i.e., coaxial) alignment with the heating chamber 108 is four. In another possible design, there are only three protrusions 140, spaced 120 degrees apart from one another. Designs with fewer than four protrusions 140 tend to allow the substrate carrier 114 to be pressed against a portion of the side wall 126 between two of the protrusions 140. Obviously, in a limited space, providing a very large number of protrusions (e.g., 30 or more) tends to result in little or no gaps between the protrusions, which can completely block the airflow path between the exterior surface of the substrate carrier 114 and the interior surface of the side wall 126, significantly reducing the ability of the aerosol-generating device to provide convective heating. However, Such a design can still be used, along with the possibility of providing a hole in the center of the base 112 to define an airflow channel. Typically, the protrusions 140 may be evenly spaced around the periphery of the sidewall 126 to help provide even compression and heating, although some variations may have an asymmetrical arrangement depending on the exact effect desired.

[0058] It will be apparent that the size and number of the protrusions 140 also allow for tuning the balance between conductive and convective heating. By increasing the width of the protrusions 140 that contact the substrate support 114 (the distance the protrusions 140 extend around the periphery of the sidewall 126), the available periphery of the sidewall 126 that acts as an airflow channel (arrow B in FIGS. 6 and 6(a)) is reduced, thereby reducing the convective heating provided by the aerosol generation device 100. However, because wider protrusions 140 contact the substrate support 114 over a larger portion of the periphery, the conductive heating provided by the aerosol generation device 100 increases. A similar effect is seen when more protrusions 140 are added, in that the periphery of the sidewall 126 available for convection decreases, while the conductive channel increases due to the increased total contact surface area between the protrusions 140 and the substrate support 114. Note that increasing the length of the protrusions 140 also reduces the volume of air in the heating chamber 108 that is heated by the heater 124, reducing convective heating, while increasing the contact surface area between the protrusions 140 and the substrate support, increasing conductive heating. Increasing the distance each protrusion 140 extends into the heating chamber 108 can help improve conductive heating without significantly reducing convective heating. Thus, the aerosol generating device 100 can be designed to balance conductive and convective heating types by varying the number and size of the protrusions 140, as described above. The heat localization effect resulting from the relatively thin sidewall 126 and the use of a material with relatively low thermal conductivity (e.g., stainless steel) ensures that conductive heating is an appropriate means of transferring heat to the substrate support 114 and subsequently to the aerosol substrate 128. Because the portions of the sidewall 126 that are heated may generally correspond to the locations of the protrusions 140, this means that the heat generated is conducted by the protrusions 140 to the substrate support 114, but is not conducted away from the substrate support. In locations that are heated but do not correspond to the protrusions 140, the heating of the sidewall 126 will result in convective heating as described above.

[0059] As shown in FIGS. 1-6, the protrusions 140 are elongated. That is, the protrusions extend a length greater than their width. In some cases, the protrusions 140 may have a length that is 5, 10, or even 25 times their width. For example, as discussed above, the protrusions 140 may extend 0.4 mm into the heating chamber 108, and in one example, the protrusions 140 may be 0.5 mm wide and 12 mm long. These dimensions are suitable for a heating chamber 108 that is 30 mm to 40 mm long. In this example, the protrusions 140 do not extend the entire length of the heating chamber 108 because, in the example given, the protrusions are shorter than the heating chamber 108. Thus, each of the protrusions 140 has a top edge 142 a and a bottom edge 142 b. The top edge 142 a is the portion of the protrusion 140 that is closest to the open end 110 of the heating chamber 108 and also closest to the flange 138. Bottom edge 142b is the end of protrusion 140 located closest to base 112. It can be seen that above top edge 142a (closer to the open end than top edge 142a) and below bottom edge 142b (closer to base 112 than bottom edge 142b), sidewall 126 is free of protrusion 140. That is, sidewall 126 is not deformed or recessed in these areas. In some instances, protrusion 140 is longer and extends all the way to the top and / or bottom of sidewall 126, such that one or both of the following are true: top edge 142a is aligned with open end 110 of heating chamber 108 (or flange 138), and bottom edge 142b is aligned with base 112. In fact, in such cases, top edge 142a and / or bottom edge 142b may not even be present.

[0060] It may be advantageous for the protrusion 140 not to extend the entire length of the heating chamber 108 (e.g., from the base 112 to the flange 138). At the upper end, the upper edge 142a of the protrusion 140 can be used as a guide to prevent the user from inserting the substrate carrier 114 too far into the aerosol generation device 100, as described below. However, it may be useful to heat areas other than just the area of ​​the substrate carrier 114 that contains the aerosol substrate 128. This is because, once the aerosol is generated, it is beneficial to maintain its temperature high (above room temperature, but not so high that it would burn the user) to prevent recondensation, which would detract from the user experience. Thus, the effective heating area of ​​the heating chamber 108 extends beyond the expected location of the aerosol substrate 128 (i.e., up the heating chamber 108 near the open end). This means that the heating chamber 108 extends above the upper edge 142 a of the protrusion 140, or equivalently, the protrusion 140 does not extend all the way to the open end of the heating chamber 108. Similarly, compression of the aerosol substrate 128 at the end 134 of the substrate carrier 114 inserted into the heating chamber 108 can cause part of the aerosol substrate 128 to fall off the substrate carrier 114 and contaminate the heating chamber 108. Therefore, it can be advantageous to position the lower edge 142 b of the protrusion 140 further from the base 112 than the expected location of the end 134 of the substrate carrier 114.

[0061] In some embodiments, the protrusions 140 are not elongated, but rather have a width approximately equal to their length. For example, the protrusions may be as wide as their height (e.g., having a square or circular outline when viewed radially), or the protrusions may be two to five times longer than their width. Note that the centering effect provided by the protrusions 140 can be achieved without the protrusions 140 being elongated. In some examples, there may be multiple sets of protrusions 140, such as an upper set near the open end of the heating chamber 108 and a lower set spaced apart from the upper set and positioned closer to the base 112. This may help ensure that the substrate support 114 is held in a coaxial configuration while reducing the retraction resistance introduced by a single set of protrusions 140 spanning the same distance. The two sets of protrusions 140 may be substantially identical, or they may differ in their length or width, or the number or arrangement of protrusions 140 configured around the sidewall 126.

[0062] In side view, the protrusions 140 are shown as having a trapezoidal profile. This means that the profile along the length of each protrusion 140, e.g., the central longitudinal cross-section of the protrusion 140, is approximately trapezoidal. That is, the upper edge 142a is generally planar and tapers to meet the sidewall 126 near the open end 110 of the heating chamber 108. In other words, the upper edge 142a has a chamfered profile. Similarly, the protrusion 140 has a lower portion 142b that is generally planar and tapers to meet the sidewall 126 near the base 112 of the heating chamber 108. That is, the lower edge 142b has a chamfered profile. In other embodiments, the upper edge 142a and / or the lower edge 142b do not taper toward the sidewall 126 but instead extend at an angle of approximately 90 degrees from the sidewall 126. In yet other embodiments, the upper edge 142a and / or the lower edge 142b have a curved or rounded shape. Bridging the upper edge 142a and the lower edge 142b are generally planar regions that contact and / or compress the substrate support 114. The planar contact portions can help provide even compression and conductive heating. In other examples, the planar portions can instead be curved portions that bend outward to contact the substrate support 128, for example, having a polygonal or curved profile (e.g., a portion of a circle).

[0063] If the protrusion 140 has an upper edge 142a, the protrusion 140 also functions to prevent over-insertion of the substrate carrier 114. As shown most clearly in Figures 4 and 6, the substrate carrier 114 has a lower portion that contains the aerosol substrate 128, which is , terminating prematurely at the boundary of the aerosol substrate 128. The aerosol substrate 128 is typically more compressible than the other regions 130 of the substrate carrier 114. Therefore, due to the reduced compressibility of the other regions 130 of the substrate carrier 114, a user inserting the substrate carrier 114 will experience increased resistance when the upper edge 142 a of the protrusion 140 aligns with the boundary of the aerosol substrate 128. To achieve this, the portion of the base 112 that the substrate carrier 114 contacts should be spaced from the upper edge 142 a of the protrusion 140 by the same distance as the length of the substrate carrier 114 occupied by the aerosol substrate 128. In some examples, the aerosol substrate 128 occupies approximately 20 mm of the substrate carrier 114, so the distance between the upper edge 142 a of the protrusion 140 and the portion of the base that the substrate carrier 114 contacts when the substrate carrier 114 is inserted into the heating chamber 108 is also approximately 20 mm.

[0064] As shown, the base 112 also includes a platform 148. The platform 148 is formed in a single step in which the base 112 is pressed from below (e.g., by hydroforming, mechanical pressure, as part of forming the heating chamber 108) to leave a depression on the outer surface (lower surface) of the base 112 and the platform 148 on the inner surface (upper surface, inside the heating chamber 108) of the base 112. When the platform 148 is formed in this way, e.g., with a corresponding depression, these terms are used interchangeably. In other cases, the platform 148 may be formed from a separate piece separately attached to the base 112 or by carving out a portion of the base 112 to leave the platform 148, in either case without the need for a corresponding depression. These latter cases can provide more variety in the shape of the platform 148 that can be realized, because it does not rely on deformation of the base 112, which (while convenient) limits the complexity with which the shape can be chosen. While the illustrated shape is generally circular, there are, of course, a wide variety of shapes that will achieve the desired effects detailed herein, including, but not limited to, polygonal, curved, and shapes that include one or more of these types of shapes. Indeed, while shown as a centrally located platform 148, in some cases there may be one or more platform elements spaced from the center, such as at the edges of the heating chamber 108. Typically, the platform 148 has a generally flat top, although hemispherical platforms or platforms having rounded, dome-shaped tops are also envisioned.

[0065] As mentioned above, the distance between the upper edge 142 a of the protrusion 140 and the portion of the base 112 that the substrate carrier 114 contacts can be carefully selected to match the length of the aerosol substrate 128 so as to provide an indication to the user that they have inserted the substrate carrier 114 as far as necessary into the aerosol generation device 100. If there is no platform 148 on the base 112, this simply means that the distance from the base 112 to the upper edge 142 a of the protrusion 140 must match the length of the aerosol substrate 128. If there is a platform 148, the length of the aerosol substrate 128 should correspond to the distance between the upper edge 142 a of the protrusion 140 and the top of the platform 148 (i.e., the portion closest to the open end 110 of the heating chamber 108 in some examples). In yet another example, the distance between the upper edge 142 a of the protrusion 140 and the top of the platform 148 is slightly less than the length of the aerosol substrate 128. This means that the tip 134 of the substrate carrier 114 must extend slightly past the top of the platform 148, causing compression of the aerosol substrate 128 at the end 134 of the substrate carrier 114. In fact, this compression effect can occur even in instances where there are no protrusions 140 on the interior surface of the sidewall 126. This compression helps prevent the aerosol substrate 128 at the end 134 of the substrate carrier 114 from falling into the heating chamber 108, thereby reducing the need for cleaning of the heating chamber 108, which can be a complex and difficult task. In addition, this compression prevents the aerosol substrate 128 at the end 134 of the substrate carrier 114 from falling into the heating chamber 108, which can be a complex and difficult task. 134, thereby mitigating the effect described above, whereby compressing this area using a protrusion 140 extending from the sidewall 126 would be undesirable because it would tend to increase the likelihood that the aerosol substrate 128 would fall out of the substrate carrier 114.

[0066] The platform 148 also provides an area where any aerosol substrate 128 that has fallen off the substrate carrier 114 can collect without obstructing the airflow path into the tip 134 of the substrate carrier 114. For example, the platform 148 divides the lower end of the heating chamber 108 (i.e., the portion closest to the base 112) into an upright portion that forms the platform 148 and a lower portion that forms the remainder of the base 112. The lower portion can receive loose pieces of aerosol substrate 128 that have fallen off the substrate carrier 114, while air can flow over such loose pieces of aerosol substrate 128 and into the end of the substrate carrier 114. To achieve this effect, the platform 148 can be about 1 mm higher than the remainder of the base 112. The platform 148 can have a diameter smaller than the diameter of the substrate carrier 114 so that the platform 148 does not obstruct the airflow through the aerosol substrate 128. Preferably, the platform 148 has a diameter of between 0.5 mm and 0.2 mm, most preferably between 0.45 mm and 0.35 mm, for example 0.4 mm (±0.03 mm).

[0067] The aerosol generating device 100 includes a user-operable button 116. In a first embodiment, the user-operable button 116 is located on a side wall 118 of the casing 102. The user-operable button 116 is configured such that activation of the user-operable button 116, for example by pressing the user-operable button 116, activates the aerosol generating device 100, heating the aerosol substrate 128 and generating an aerosol for inhalation. In some embodiments, the user-operable button 116 is also configured to allow a user to activate other functions of the aerosol generating device 100 and / or illuminate a light to indicate the status of the aerosol generating device 100. In other examples, a separate light (e.g., one or more LEDs or other suitable light source) may be provided to indicate the status of the aerosol generating device 100. In this context, status may refer to one or more of the following: remaining battery charge, heater status (e.g., on, off, error, etc.), device status (e.g., whether ready to take a puff), or other status indicators, such as error mode, number of puffs consumed, whether the entire substrate carrier 114 has been consumed, or puffs remaining before the power source is depleted.

[0068] In a first embodiment, the aerosol generating device 100 is electrically powered, i.e., configured to heat the aerosol substrate 128 using electrical power. To this end, the aerosol generating device 100 includes a power source 120, e.g., a battery. The power source 120 is coupled to a control circuit 122, which is in turn coupled to a heater 124. A user-operable button 116 is configured to couple and decouple the power source 120 to the heater 124 via the control circuit 122. In this embodiment, the power source 120 is located toward the first end 104 of the aerosol generating device 100. This allows the power source 120 to be spaced apart from the heater 124, which is located toward the second end 106 of the aerosol generating device 100. In other embodiments, the heating chamber 108 is heated in other ways, for example, by burning a combustible gas.

[0069] The heater 124 is attached to the outer surface of the heating chamber 108. The heater 124 is mounted on a metal layer 144, which is itself in contact with the outer surface of the sidewall 126. The metal layer 144 forms a band around the periphery of the heating chamber 108 to match the shape of the outer surface of the sidewall 126. The heater 124 is mounted in the center of the metal layer 144. 1-6 is attached to the intermediate portion of the heating chamber 108 between the base 112 and the open end 110, and to the area of ​​the exterior surface covered by the metal layer 114. In other embodiments, the heater 124 may be attached to other portions of the heating chamber 108 or may be contained within the sidewall 126 of the heating chamber 108; it is noted that it is not necessary for the exterior of the heating chamber 108 to include the metal layer 144.

[0070] As shown in FIG. 7 , the heater 124 includes a heating element 164, an electrical connection track 150, and a backing film 166. The heating element 164 is configured so that when an electric current is passed through the heating element 164, the heating element 164 heats up and its temperature increases. The heating element 164 is shaped to avoid sharp corners, which could induce hot spots or melting points in the heater 124. The heating element 164 also has a uniform width, and portions of the element 164 that extend close to each other are spaced approximately equal distances apart. The heating element 164 in FIG. 7 shows two resistive paths 164a, 164b, each of which takes a serpentine path over the area of ​​the heater 124 to cover as much area as possible while adhering to the criteria described above. These paths 164a, 164b are configured electrically in parallel with each other in FIG. 7 . It should be noted that other numbers of paths, such as three paths, one path, or multiple paths, can be used. The paths 164a, 164b do not cross to avoid short circuits. The heating element 164 is configured to have a resistance to produce the correct power density for the level of heating required. In some examples, the heating element 164 has a resistance between 0.4 Ω and 2.0 Ω, with 0.5 Ω to 1.5 Ω being particularly advantageous, and more particularly between 0.6 Ω and 0.7 Ω.

[0071] The electrical connection tracks 150 are shown as part of the heater 124, but in some embodiments may be replaced by wires or other connection elements. The electrical connections 150 are used to provide power to the heating element 164 and complete a circuit with the power supply 120. The electrical connection tracks 150 are shown extending vertically downward from the heating element 164. With the heater 124 in place, the electrical connections 150 extend beyond the base 112 of the heating chamber 108 and through the base 156 of the insulating member 152 to connect with the control circuit 122.

[0072] The backing film 166 may be a single sheet to which the heating element 164 is attached, or may form an envelope that sandwiches the heating element between two sheets 166a, 166b. In some embodiments, the backing film 166 is formed from polyimide. In some embodiments, the thickness of the backing film 166 is minimized to reduce the thermal mass of the heater 124. For example, the thickness of the backing film 166 may be 50 μm, or 40 μm, or 25 μm.

[0073] A heating element 164 is attached to the sidewall 108. In Figure 7, the heating element 164 is configured to wrap once around the heating chamber 108 by carefully selecting the size of the heater 124. This ensures that the heat generated by the heater 124 is distributed approximately evenly around the surface covered by the heater 124. It should be noted that in some examples, the heater 124 may wrap an integral number of times around the heating chamber 108, rather than just once.

[0074] It should also be noted that the height of the heater 124 is approximately 14 mm to 15 mm. The circumference of the heater 124 (or its length before being applied to the heating chamber 108) is approximately 24 mm to 25 mm. The height of the heating element 164 may be less than 14 mm. This allows for a heating element 164 to be heated. The heating element 164 can be positioned entirely inside the backing film 166 of the heater 124, with a boundary around the heating element 164. Thus, the area covered by the heater 124 is, in some embodiments, approximately 3.75 cm 2 It could be.

[0075] The power used by the heater 124 is provided by a power supply 120, which in this embodiment is in the form of a cell (or battery). The voltage provided by the power supply 120 is a regulated or boosted voltage. For example, the power supply 120 may be configured to generate a voltage in the range of 2.8 V to 4.2 V. In one example, the power supply 120 is configured to generate a voltage of 3.7 V. Assuming an exemplary resistance of the heating element 164 in one embodiment is 0.6 Ω and an exemplary voltage of 3.7 V, this would result in a power output of approximately 30 W for the heating element 164. Note that based on the exemplary resistance and voltage, the power output may be between 15 W and 50 W. The cells forming the power supply 120 may be rechargeable cells, or alternatively, may be single-use cells 120. The power supply is typically configured to provide power for 20 or more thermal cycles. This allows a user to use 20 full packets of substrate carriers 114 on a single charge of the aerosol generating device 100. The cells may be lithium-ion cells or any other type of commercially available cell. The cells may be, for example, 18650 cells or 18350 cells. If the cells are 18350 cells, the aerosol generating device 100 may be configured to store enough charge for 12 thermal cycles, or indeed 20 thermal cycles, allowing a user to consume 12 or 20 substrate carriers 114.

[0076] One important value for the heater 124 is the power per unit area it generates. This is a measure of how much heat can be delivered by the heater 124 to the area in contact with it (in this case, the heating chamber 108). In the example described, this is 4 W / cm 2 ~13.5W / cm 2 The maximum power density rating for the heater is typically in the range of 2 W / cm, depending on the design. 2 ~10W / cm 2Therefore, in some of these embodiments, a copper or other conductive metal layer 144 may be provided on the heating chamber 108 to efficiently conduct heat away from the heater 124 and reduce the possibility of damage to the heater 124.

[0077] The power supplied by the heater 124 may be constant in some embodiments and may not be constant in other embodiments. For example, the heater 124 may provide variable power via a duty cycle, or more specifically, a pulse-width modulation cycle. This allows the power to be supplied in pulses, allowing the time-averaged power output by the heater 124 to be easily controlled by simply selecting the ratio of "on" time to "off" time. The level of power output by the heater 124 may also be controlled by additional control means, such as manipulating the current or voltage.

[0078] As shown in FIG. 7 , the aerosol generating device 100 includes a temperature sensor 170 for detecting the temperature of the heater 124 or the temperature of the environment surrounding the heater 124. The temperature sensor 170 may be, for example, a thermistor, a thermocouple, or any other thermometer. For example, a thermistor may be formed from a glass bead encapsulating a resistive material, which is connected to a voltmeter and through which a known current flows. Thus, as the temperature of the glass changes, the resistance of the resistive material changes in a predictable manner, and thus its temperature can be determined from the voltage drop across the resistive material at a constant current (a constant voltage mode is also possible). In some embodiments, the temperature sensor 170 is positioned on a surface of the heating chamber 108, for example, in a recess formed in the exterior surface of the heating chamber 108. The recess may be as described elsewhere herein, for example, part of the protrusion 140, or it may be a recess specially provided to hold the temperature sensor 170. In the illustrated embodiment, the temperature sensor 170 is mounted on the backing layer 166 of the heater 124. In other embodiments, the temperature sensor 170 is integral with the heating element 164 of the heater 124, in the sense that the temperature is detected by monitoring changes in the resistance of the heating element 164.

[0079] In the first embodiment of the aerosol generating device 100, the time to first puff after starting the aerosol generating device 100 is an important parameter. Users of the aerosol generating device 100 will appreciate that it is preferable to minimize the delay between starting the aerosol generating device 100 and inhaling the aerosol from the substrate carrier 128, thereby initiating inhalation of the aerosol from the substrate carrier 128 as soon as possible. Thus, during the first stage of heating, the power supply 120 provides 100% of its available power to the heater 124, for example, by setting the duty cycle to always on or by manipulating the product of voltage and current to its maximum possible value. This may be for a period of 30 seconds, more preferably a period of 20 seconds, or any period until the temperature sensor 170 provides a reading corresponding to 240°C. Typically, the substrate carrier 114 may operate optimally at 180°C. Nevertheless, it may be advantageous to heat the temperature sensor 170 above this temperature so that the user can extract the aerosol from the substrate carrier 114 as quickly as possible. This is because the aerosol substrate 128 is heated by convection of warm air through the aerosol substrate 128 and, to some extent, by conduction between the protrusions 140 and the exterior surface of the substrate carrier 114, so the temperature of the aerosol substrate 128 typically lags behind (i.e., is lower than) the temperature detected by the temperature sensor 170. In contrast, the temperature sensor 170, because it maintains good thermal contact with the heater 124, measures a temperature closer to that of the heater 124 rather than that of the aerosol substrate 128. In practice, because accurately measuring the temperature of the aerosol substrate 128 can be difficult, heating cycles are often determined experimentally, where different heating profiles and heater temperatures are tried and the various aerosol components formed at those temperatures are monitored for aerosols generated by the aerosol substrate 128. An optimal cycle delivers aerosol as quickly as possible while avoiding the generation of combustion products due to overheating of the aerosol substrate 128.

[0080] The temperature detected by the temperature sensor 170 may be used to set the level of power delivered by the cell 120, for example, by forming a feedback loop in which the temperature detected by the temperature sensor 170 is used to control the power supply cycle of the heater. The heating cycle described below may be for the case in which a user desires to consume a single substrate support 114.

[0081] In a first embodiment, the heater 124 extends around the periphery of the heating chamber 108. That is, the heater 124 surrounds the heating chamber 108. More specifically, the heater 124 extends around the periphery of the sidewall 126 of the heating chamber 108, but does not extend around the periphery of the base 112 of the heating chamber 108. The heater 124 does not extend across the entire sidewall 126 of the heating chamber 108. Rather, the heater extends around the entire periphery of the sidewall 126, but only a portion of the length of the sidewall 126. In this context, this length is the length from the base 112 to the open end 110 of the heating chamber 108. In other embodiments, the heater 124 extends along the entire length of the sidewall 126. In yet other embodiments, the heater 124 comprises two heating portions separated by a gap, thereby leaving a central portion of the heating chamber 108 uncovered, e.g., a portion of the sidewall 126 midway between the base 112 and the open end 110 of the heating chamber 108. In other embodiments, the heating chamber 108 is cup-shaped, and therefore the heater 110 is similarly cup-shaped, e.g., the heater extends completely around the base 112 of the heating chamber 108. In still other embodiments, the heater 124 comprises multiple heating elements 164 distributed closely spaced about the heating chamber 108. In some embodiments, there are spaces between the heating elements 164. In other embodiments, the heating elements overlap one another. In some embodiments, the heating elements 164 may be spaced apart around the circumference of the heat chamber 108 or sidewall 126, e.g., laterally, while in other embodiments, the heating elements 164 may be spaced apart along the length of the heat chamber 108 or sidewall 126, e.g., longitudinally. It will be appreciated that the heater 124 in the first embodiment is located outside of, on the exterior surface of, the heat chamber 108. The heater 124 is located in good thermal contact with the heat chamber 108, allowing for good transfer of heat between the heater 124 and the heat chamber 108.

[0082] The metal layer 144 can be formed from copper or any other material (e.g., a metal or alloy) with high thermal conductivity, such as gold or silver. In this context, high thermal conductivity may refer to a metal or alloy with a thermal conductivity of 150 W / mK or greater. The metal layer 144 can be applied by any suitable method, such as electroplating. Other methods for applying the layer 144 include applying metal tape to the heat chamber 108, chemical vapor deposition, physical vapor deposition, etc. Electroplating is a convenient method for applying the layer 144, but requires that the area onto which the layer 144 is plated be electrically conductive. This is not required for other deposition methods, and these other methods open up the possibility of the heat chamber 108 being formed from a non-conductive material, such as a ceramic, that may have useful thermal properties. Also, when a layer is described as metal, this should generally be interpreted as meaning "formed from a metal or alloy," although in this context, metal refers to a material with a relatively high thermal conductivity (>150 W / mK). If the metal layer 144 is electroplated onto the sidewall 126, it may be necessary to first form a "strike layer" to ensure that the electroplated layer adheres to the exterior surface. For example, if the metal layer 144 is copper and the sidewall 126 is stainless steel, a nickel strike layer is often used to ensure good adhesion. Electroplated and deposited layers have the advantage of improving thermal conductivity between the two elements, since there is direct contact between the metal layer 144 and the material of the sidewall 126.

[0083] Regardless of which method is used to form the metal layer 144, the thickness of the layer 144 is typically somewhat thinner than the thickness of the sidewall 126. For example, the thickness of the metal layer may range from 10 μm to 50 μm, or from 10 μm to 30 μm, e.g., approximately 20 μm. If a strike layer is used, it may be even thinner than the metal layer 144, e.g., 10 μm or even 5 μm. As explained in more detail below, the purpose of the metal layer 144 is to distribute the heat generated by the heater 124 over an area larger than the area occupied by the heater 124. Once this effect is sufficiently achieved, there is little advantage to making the metal layer 144 thicker, as this simply increases the thermal mass and reduces the efficiency of the aerosol generating device 100.

[0084] 1-6, it is apparent that the metal layer 144 extends over only a portion of the exterior surface of the sidewall 126. This not only reduces the thermal mass of the heating chamber 108, but also allows for a defined heating area. Generally, because the metal layer 144 has a higher thermal conductivity than the sidewall 126, heat generated by the heater 124 spreads rapidly throughout the area covered by the metal layer 144, whereas because the sidewall 126 is thinner and has a relatively lower thermal conductivity than the metal layer 144, heat remains relatively localized to the area of ​​the sidewall 126 covered by the metal layer 144. Selective electroplating is achieved by masking portions of the heating chamber 108 with a suitable tape (e.g., polyester or polyimide) or silicone rubber mold. Other plating methods may use different tape or masking methods, as appropriate.

[0085] 1-6, the metal layer 144 overlaps the entire length of the heating chamber 108 along which the protrusions / indentations 140 extend. This allows the protrusions 140 to be heated by the thermal conduction effect of the metal layer 144, thereby providing the conductive heating described above. This means that the area of ​​the metal layer 144 generally corresponds to the area of ​​the heated region, so in many cases it is not necessary for the metal layer to extend to the top and bottom of the heating chamber 108 (i.e., the open end and the area nearest the base 112). As noted above, the area of ​​the substrate support 114 to be heated begins just above the boundary of the aerosol substrate 128 and extends toward, but often does not include, the end 134 of the substrate support 114. As noted above, the metal layer 144 has the effect of spreading the heat generated by the heater 124 over a larger area than the area occupied by the heater 124 itself. This means that the area of ​​the substrate support 114 that is heated by the metal layer 144 will generally correspond to the area of ​​the heated region, so in many cases it will not need to extend to the top and bottom of the heating chamber 108 (i.e., the open end and the area nearest the base 112). As noted above, the metal layer 144 has the effect of spreading the heat generated by the heater 124 over a larger area than the area occupied by the heater 124 itself. 2 This means that more power can be supplied to the heater 124 than would be nominally possible based on the surface area occupied by the heater 124 and the heat generated, since the effective area of ​​the heater 124 is greater than the surface area actually occupied by the heater 124, since the heat generated is spread over a larger area.

[0086] Because the heating zones can be defined by the portions of the sidewalls 126 that are covered by the metal layer 144, it is less important to precisely position the heater 124 outside of the heating chamber 108. For example, instead of having to align the heater 124 a specific distance from the top or bottom of the sidewalls 126, the metal layer 144 can be formed in a very specific area and the heater 124 can be positioned over the top of the metal layer 144, thereby spreading the heat across the metal layer 144 area or heating zone as described above. Standardizing the masking process for electroplating or deposition is often easier than precisely aligning the heater 124.

[0087] Similarly, where there is a protrusion 140 formed by indenting the sidewall 126, the indentation represents a portion of the sidewall 126 that does not contact the heater 124 wrapped around the heating chamber 108; instead, the heater 124 tends to bridge over the indentation, leaving a gap. The metal layer 144 can help mitigate this effect because even portions of the sidewall 126 that are not in direct contact with the heater 124 receive heat from the heater 124 by conduction through the metal layer 144. In some cases, the heater element 164 may be configured to minimize overlap between the heater element 164 and the indentation on the exterior surface of the sidewall 126, for example, by configuring the heating element 164 to cross the indentation but not extend along it. In other cases, the heater 124 is positioned on the exterior surface of the sidewall 126 such that the portion of the heater 124 that overlies the indentation results in a gap between the heater element 164. Whatever method is chosen to mitigate the effect of heater 124 overlying the recess, metal layer 144 mitigates that effect by conducting heat into the recess. In addition, metal layer 144 provides additional thickness to the recessed regions of sidewall 126, thereby providing additional structural support to these regions. In fact, the additional thickness provided by metal layer 126 strengthens thin sidewall 126 in all areas covered by metal layer 144.

[0088] The metal layer 144 can be formed before or after forming a recess in the sidewall 126 of the exterior surface to provide the protrusion 140 that extends into the heating chamber 108. Forming the recess before the metal layer is preferable because, once the metal layer 144 is formed, processes such as annealing tend to damage the metal layer 144, and the increased thickness of the sidewall 126 combined with the metal layer 144 makes it more difficult to stamp out the sidewall 126 to form the protrusion 140. However, if the recess is formed before the metal layer 144 is formed on the sidewall 126, it is much easier to form the metal layer 144 so that it extends beyond the recess (i.e., upward and downward) because it is difficult to mask the exterior surface of the sidewall 126 so that the metal layer extends into the recess. Any gap between the masking and the sidewall 126 could allow the metal layer 144 to deposit underneath the masking.

[0089] An insulating layer 146 is wrapped around the heater 124. This layer 146 is under tension, providing a compressive force to the heater 124 and holding the heater 124 tightly against the exterior surface of the sidewall 126. Advantageously, this insulating layer 146 is a heat-shrink material. This allows the insulating layer 146 to be tightly wrapped around the heating chamber (over the heater 124, metal layer 144, etc.) and then heated. Upon heating, the insulating layer 146 shrinks, pressing the heater 124 tightly against the exterior surface of the sidewall 126 of the heating chamber 108. This eliminates any air gaps between the heater 124 and the sidewall 126, and keeps the heater 124 in very good thermal contact with the sidewall. This ensures good efficiency, since the heat generated by the heater 124 heats the sidewall (and subsequently the aerosol substrate 128) and is not wasted or otherwise leaked in heating the air.

[0090] In a preferred embodiment, a heat-shrink material is used, such as a treated polyimide tape that shrinks in only one direction. For example, in the case of polyimide tape, the tape can be configured to shrink only in the length direction. This means that the tape can be wrapped around the heating chamber 108 and heater 124 and, upon heating, will shrink, pressing the heater 124 against the sidewall 126. Because the insulating layer 146 shrinks in the length direction, the force thus generated is uniform and directed inward. If the tape were to shrink in the lateral (width) direction, this could cause wrinkles in the heater 124 or the tape itself. This would then introduce gaps and reduce the efficiency of the aerosol generating device 100.

[0091] Referring to Figures 3-6, the substrate carrier 114 includes a pre-packaged amount of aerosol substrate 128 along with an aerosol collection area 130 enclosed within an outer layer 132. The aerosol substrate 128 is located toward a first end 134 of the substrate carrier 114. The aerosol substrate 128 extends across the entire width of the substrate carrier 114 within the outer layer 132. The aerosol substrates also abut each other midway along the substrate carrier 114, meeting at a boundary. Overall, the substrate carrier 114 is generally cylindrical. In Figures 1 and 2, the aerosol generation device 100 is shown without the substrate carrier 114. In Figures 3 and 4, the substrate carrier 114 is shown above the aerosol generation device 100 but is not loaded within the aerosol generation device 100. In Figures 5 and 6, the substrate carrier 114 is shown loaded into the aerosol generation device 100.

[0092] When a user wishes to use the aerosol generation device 100, the user first loads the substrate carrier 114 into the aerosol generation device 100. This involves inserting the substrate carrier 114 into the heating chamber 108. The substrate carrier 114 is inserted into the heating chamber 108 with the first end 134 of the substrate carrier 114, which is located on the side where the aerosol substrate 128 is located, oriented so that it is within the heating chamber 108. The substrate carrier 114 is inserted into the heating chamber 108 until the first end 134 of the substrate carrier 114 comes to rest against a platform 148 extending inward from the base 112 of the heating chamber 108, i.e., until the substrate carrier 114 cannot be inserted further into the heating chamber 108. In the embodiment shown, as described above, there is an additional effect from the interaction between the upper edge 142a of the protrusion 140 and the boundary of the adjacent less compressible region of the aerosol substrate 128 and the substrate carrier 114, which alerts the user that the substrate carrier 114 has been inserted sufficiently deep into the aerosol generation device 100. It can be seen from FIGS. 3 and 4 that when the substrate carrier 114 is inserted as deep as possible into the heating chamber 108, only a portion of the length of the substrate carrier 114 is inside the heating chamber 108. The remainder of the length of the substrate carrier 114 protrudes from the heating chamber 108. At least a portion of the remainder of the length of the substrate carrier 114 also protrudes from the second end 106 of the aerosol generation device 100. In the first embodiment, the entire remainder of the length of the substrate carrier 114 protrudes from the second end 106 of the aerosol generation device 100. That is, the opening of the heating chamber 108 The end 110 is coincident with the second end 106 of the aerosol generation device 100. In other embodiments, all or substantially all of the substrate carrier 114 may be contained within the aerosol generation device 100 such that no portion, or substantially no portion, of the substrate carrier 114 protrudes from the aerosol generation device 100.

[0093] When the substrate carrier 114 is inserted into the heating chamber 108, the aerosol substrate 128 within the substrate carrier 114 is configured to be at least partially within the heating chamber 108. In a first embodiment, the aerosol substrate 128 is completely within the heating chamber 108. In fact, the pre-packaged amount of aerosol substrate 128 within the substrate carrier 114 is configured to extend from the first end 134 of the substrate carrier 114 along the substrate carrier 114 a distance that is approximately (or exactly) equal to the interior height of the heating chamber 108 from the base 112 to the open end 110 of the heating chamber 108. This is effectively the same as the length of the sidewall 126 of the heating chamber 108 that is inside the heating chamber 108.

[0094] With the substrate carrier 114 loaded into the aerosol generation device 100, the user turns on the aerosol generation device 100 using the user-operable button 116. This causes power from the power source 120 to be supplied to the heater 124 via (and under the control of) the control circuit 122. The heater 124 conducts heat into the aerosol substrate 128 via the protrusions 140, heating the aerosol substrate 128 to a temperature at which the aerosol substrate 128 can begin to emit vapor. Once heated to a temperature at which vapor can begin to be emitted, the user can inhale the vapor by drawing the vapor through the second end 136 of the substrate carrier 114. That is, vapor is generated from the aerosol substrate 128 located at the first end 134 of the substrate carrier 114 within the heating chamber 108, drawn along the length of the substrate carrier 114, through the vapor collection area 130 within the substrate carrier 114, and to the second end 136 of the substrate carrier, where it enters the user's mouth. This steam flow is shown by arrow A in FIG.

[0095] It will be appreciated that when a user inhales vapor in the direction of arrow A in FIG. 6, the vapor flows from the vicinity of the aerosol substrate 128 within the heating chamber 108. This action draws ambient air from the environment surrounding the aerosol-generating device 100 into the heating chamber 108 (via the flow path indicated by arrow B in FIG. 6 and shown in more detail in FIG. 6(a)). This ambient air is then heated by the heater 124, which in turn heats the aerosol substrate 128 to generate the aerosol. More specifically, in the first embodiment, air enters the heating chamber 108 through a space provided between the sidewall 126 of the heating chamber 108 and the outer layer 132 of the substrate carrier 114. For this purpose, the outer diameter of the substrate carrier 114 is smaller than the inner diameter of the heating chamber 108. More specifically, in the first embodiment, the heating chamber 108 has an inner diameter (e.g., where no protrusions are present, e.g., when the protrusions 140 are not present or between the protrusions 140) of 10 mm or less, preferably 8 mm or less, and most preferably about 7.6 mm. This allows the substrate carrier 114 to have a diameter of about 7.0 mm (±0.1 mm) (where not compressed by the protrusions 140). This corresponds to a circumference of 21 mm to 22 mm, more preferably 21.75 mm. In other words, the spacing between the substrate carrier 114 and the sidewall 126 of the heating chamber 108 is most preferably about 0.1 mm. In other variations, the spacing is at least 0.2 mm, and in some embodiments, at most 0.3 mm. Arrow B in FIG. 6 indicates the direction in which air is drawn into the heating chamber 108.

[0096] When a user activates the aerosol generating device 100 by actuating the user-operable button 116, the aerosol generating device 100 heats the aerosol substrate 128 to a temperature sufficient to cause a portion of the aerosol substrate 128 to vaporize. More specifically, the control circuit 122 supplies power from the power supply 120 to the heater 124 to vaporize the aerosol substrate 128. 8 to a first temperature. Once the aerosol substrate 128 reaches the first temperature, the components of the aerosol substrate 128 begin to vaporize. That is, the aerosol substrate generates vapor. Once vapor is generated, the user can inhale the vapor through the second end 136 of the substrate carrier 114. In some scenarios, the user may know that it will take a certain amount of time for the aerosol generating device 100 to heat the aerosol substrate 128 to the first temperature and for the aerosol substrate 128 to begin generating vapor. This means that the user can determine for themselves when to begin inhaling the vapor. In other scenarios, the aerosol generating device 100 is configured to emit an indicator to the user that vapor is available for inhalation. Indeed, in the first embodiment, the control circuit 122 illuminates the user-operable button 116 when the aerosol substrate 128 has been at the first temperature for an initial period of time. In other embodiments, the indicator is provided by another indicator, such as by generating a sound or by vibrating a vibrator. Similarly, in other embodiments, the indication is provided after a fixed period of time from the aerosol generating device 100 being activated, as soon as the heater 124 reaches operating temperature, or following some other event.

[0097] The user can continue to inhale vapor as long as the aerosol substrate 128 is capable of continuing to generate vapor, e.g., as long as vaporizable components remain in the aerosol substrate 128 for vaporization into a suitable vapor. The control circuit 122 adjusts the power supplied to the heater 124 to ensure that the temperature of the aerosol substrate 128 does not exceed a threshold level. Specifically, at a certain temperature, depending on the composition of the aerosol substrate 128, the aerosol substrate 128 will begin to burn. This is not a desired effect, and temperatures above this temperature are avoided. To assist with this, the aerosol generating device 100 is provided with a temperature sensor 170. The control circuit 122 is configured to receive an indication of the temperature of the aerosol substrate 128 from the temperature sensor and use that indication to control the power supplied to the heater 124. For example, in one scenario, the control circuit 122 provides maximum power to the heater 124 for an initial period of time until the heater or chamber reaches a first temperature. Subsequently, once the aerosol substrate 128 reaches the first temperature, the control circuit 122 stops supplying power to the heater 124 for a second period of time until the aerosol substrate 128 reaches a second temperature that is lower than the first temperature. Subsequently, once the heater 124 reaches the second temperature, the control circuit 122 begins supplying power to the heater 124 for a third period of time until the heater 124 again reaches the first temperature. This may continue until the aerosol substrate 128 is depleted (i.e., all aerosol that can be generated by heating has already been generated) or until the user stops using the aerosol generating device 100. In another scenario, once the first temperature is reached, the control circuit 122 reduces the power supplied to the heater 124 to maintain the aerosol substrate 128 at the first temperature but not increase the temperature of the aerosol substrate 128.

[0098] A single inhalation by a user is commonly referred to as a "puff." In some scenarios, it is desirable to emulate the experience of smoking a cigarette. This means that the aerosol generating device 100 is typically capable of holding enough aerosol substrate 128 to provide 10-15 puffs.

[0099] In some embodiments, the control circuit 122 is configured to count puffs and turn off the heater 124 after the user has taken 10-15 puffs. Counting puffs is accomplished in one of a variety of ways. In some embodiments, the control circuit 122 determines when the temperature drops during a puff. This is because cooling is caused as fresh, cool air flows past the temperature sensor 170, which is detected by the temperature sensor. In other embodiments, the airflow is detected directly using a flow detector. Other suitable methods will be apparent to those skilled in the art. In other embodiments, the control circuit additionally Alternatively, the heater 124 may be turned off after a predetermined time has elapsed since the first puff, both to reduce power consumption and to provide a backup switch off if the puff counter fails to properly register that the predetermined number of puffs has been taken.

[0100] In some examples, the control circuit 122 is configured to provide power to the heater 124 to follow a predetermined heating cycle that takes a predetermined amount of time to complete. Once the cycle is complete, the heater 124 is turned off completely. In some cases, this cycle may utilize a feedback loop between the heater 124 and the temperature sensor 170. For example, the heating cycle may be parameterized by a series of temperatures to which the heater 124 (or, more precisely, the temperature sensor) is heated or cooled. The temperatures and duration of such a heating cycle can be empirically determined to optimize the temperature of the aerosol substrate 128. This may be necessary because, for example, where the outer layer of the aerosol substrate 128 is at a different temperature than the core, direct measurement of the aerosol substrate temperature may be impractical or misleading.

[0101] In the following example, the time to the first puff is 20 seconds. From this point on, the level of power supplied to the heater 124 is reduced from 100% so that the temperature remains constant at approximately 240°C for approximately 20 seconds. The power supplied to the heater 124 can then be further reduced so that the temperature recorded by the temperature sensor 170 is approximately 200°C. This temperature is held for approximately 60 seconds. The power level may then be further reduced so that the temperature measured by the temperature sensor 170 drops to the operating temperature of the substrate carrier 114, which in this case is approximately 180°C. This temperature may be held for 140 seconds. This time interval may be determined by the length of time the substrate carrier 114 may be used. For example, the substrate carrier 114 may stop generating aerosol after a set period of time, and thus the period during which the temperature is set to 180°C may allow the heating cycle to continue for this duration. After this point, the power supplied to the heater 124 may be reduced to zero. Even when the heater 124 is turned off, any aerosol or vapor generated while the heater 124 was on can still be drawn from the aerosol generating device 100 by the user inhaling it. Thus, even when the heater 124 is turned off, the user may be alerted to this situation by the visual indicator remaining on, even though the heater 124 has already been turned off in preparation for the end of the aerosol inhalation session. In some embodiments, this set period may be 20 seconds. The total duration of the heating cycle may be approximately 4 minutes in some embodiments.

[0102] The above exemplary thermal cycle may be modified by a user's use of the substrate carrier 114. As a user extracts aerosol from the substrate carrier 114, the user's breath encourages cool air to flow through the open end of the heating chamber 108, past the heater 124, and toward the base 112 of the heating chamber 108. The air may then enter the substrate carrier 114 through the tip 134 of the substrate carrier 114. As the cool air enters the cavity of the heating chamber 108, replacing the previously present hot air, the temperature measured by the temperature sensor 170 decreases. If the temperature sensor 170 senses a decrease in temperature, this may be used to increase the power supplied by the cell to the heater, heating the temperature sensor 170 back up to the operating temperature of the substrate carrier 114. This may be achieved by supplying a maximum amount of power to the heater 124, or alternatively, by supplying an amount of power greater than necessary to maintain a constant temperature reading from the temperature sensor 170.

[0103] The power supply 120 is configured to at least generate aerosol substrate 128 in a single substrate carrier 114 for up to This is sufficient to raise the aerosol substrate 128 to a first temperature and maintain it at the first temperature to provide vapor sufficient for at least 10-15 puffs. More generally, consistent with emulating the experience of smoking, power source 120 is typically sufficient to repeat this cycle (raising aerosol substrate 128 to a first temperature and maintaining the first temperature and vapor production for 10 to 15 puffs) 10 or even 12 times, thereby emulating the user experience of smoking a packet of cigarettes before power source 120 needs to be replaced or recharged.

[0104] In general, the efficiency of the aerosol generating device 100 is improved if as much of the heat generated by the heater 124 as possible is directed to heating the aerosol substrate 128. To this end, the aerosol generating device 100 is typically configured to provide heat in a controlled manner to the aerosol substrate 128 while reducing heat flow to other parts of the aerosol generating device 100. In particular, heat flow to parts of the aerosol generating device 100 that are handled by a user is kept to a minimum, so that these parts remain cool and comfortable to hold, for example, by insulation as described in more detail herein.

[0105] 1-6 and the accompanying description, it can be seen that, according to a first embodiment, a heating chamber 108 for an aerosol generating device 100 is provided, the heating chamber 108 comprising an open end 110, a base 112, and a sidewall 126 between the open end 110 and the base 112, the sidewall 126 having a first thickness and the base 112 having a second thickness greater than the first thickness. Reducing the thickness of the sidewall 126 can help reduce the power consumption of the aerosol generating device 100, as it reduces the energy required to heat the heating chamber 108 to a desired temperature.

[0106] Second embodiment A second embodiment will now be described with reference to Figure 8. The aerosol generating device 100 of the second embodiment is identical to the aerosol generating device 100 of the first embodiment described with reference to Figures 1 to 6, except as described below, and the same reference numerals are used to refer to similar features. The aerosol generating device 100 of the second embodiment has a configuration that allows air to be drawn into the heating chamber 108 during use, which differs from the first embodiment.

[0107] 8, a channel 113 is provided in the base 112 of the heating chamber 108. The channel 113 is located in the center of the base 112. The channel extends through the base 112 so as to be in fluid communication with the environment outside the outer casing 102 of the aerosol generating device 100. More specifically, the channel 113 is in fluid communication with the inlet 137 of the outer casing 102.

[0108] The inlet 137 extends through the outer casing 102. The channel is located partway along the length of the outer casing 102 between the first end 104 and the second end 106 of the aerosol generating device 100. In a second embodiment, the outer casing defines a gap 139 adjacent the control circuit 122 between the inlet 137 in the outer casing 102 and the channel 113 in the base 112 of the heating chamber 108. The gap 139 provides fluid communication between the inlet 137 and the channel 113, allowing air to pass from the environment outside the outer casing 102 through the inlet 137, the gap 139, and the channel 113 into the heating chamber 108.

[0109] During use, as vapor is inhaled by a user at the second end 136 of the substrate carrier 114, air is drawn into the heating chamber 108 from the environment surrounding the aerosol generating device 100. More specifically, air passes through the inlet 139 in the direction of arrow C and into the void 139. From the void 139, air passes through the channel 113 in the direction of arrow D. The aerosol substrate 128 is then drawn into the heating chamber 108, allowing first the vapor, and then the vapor mixed with air, to be drawn through the substrate carrier 114 in the direction of arrow D and inhaled by the user at the second end 136 of the substrate carrier 114. The air is generally heated as it enters the heating chamber 108, so that the air assists in transferring heat to the aerosol substrate 128 by convection.

[0110] It will be appreciated that the air flow path through the heating chamber 108 is generally linear in the second embodiment, i.e., the flow path extends in a generally straight line from the base 112 of the heating chamber 108 to the open end 110 of the heating chamber 108. The configuration of the second embodiment also allows for a reduced gap between the sidewall 126 of the heating chamber 108 and the substrate carrier. Indeed, in the second embodiment, the diameter of the heating chamber 108 is less than 7.6 mm, and the spacing between the 7.0 mm diameter substrate carrier 114 and the sidewall 126 of the heating chamber 108 is less than 1 mm.

[0111] In variations of the second embodiment, the location of the inlet 137 is different. In one particular embodiment, the inlet 137 is located at the first end 104 of the aerosol generation device 100. This allows the passage of air throughout the aerosol generation device 100 to be generally linear, e.g., air enters the aerosol generation device 100 at the first end 104, which is typically pointed distal to a user during use, flows through (or over, through, etc.) the aerosol substrate 128 within the aerosol generation device 100, and then enters the user's mouth at the second end 136 of the substrate carrier 114, which is typically pointed proximal to the user during use, e.g., toward the user's mouth.

[0112] Third embodiment A third embodiment will now be described with reference to Figures 9, 9(a), and 9(b). The aerosol generating device 100 of the third embodiment is identical to the aerosol generating device 100 of the first embodiment described with reference to Figures 1 to 6, except as described below, and the same reference numerals are used to refer to similar features. It is also possible for the heating chamber 108 of the third embodiment to correspond to the heating chamber 108 of the second embodiment, for example, with a channel 113 provided in the base 112 of the heating chamber 108, except as described below, and this forms a further embodiment of the present disclosure.

[0113] The aerosol generating device 100 of the third embodiment has a heating chamber 108 in which the base 112 is formed as a separate element, instead of being integral with the sidewall 126 as shown in Figures 1 to 6 .

[0114] Establishing the heating chamber 108 with a separate base provides the structural support described in connection with the first embodiment. Furthermore, such a base 112 can be formed from a different material than the material from which the sidewalls 126 are formed, e.g., a material with lower thermal conductivity than the sidewalls 126. Heating the first end 134 of the substrate carrier 114 can be problematic because it can lead to the generation of undesirable aerosol components. Providing an insulating portion in the base 112 of the heating chamber 108 can reduce heat conduction to the first end 134 of the substrate carrier 114, thereby mitigating the undesirable effects of heating the first end 134 of the substrate carrier 114. Indeed, if a platform 148 is present, the platform 148 can be provided as a separate component from the base 112. This separate platform 148 can include an insulating component (relative to the base 112 and / or the sidewalls 126), thereby reducing undesirable heating of the first end 134 of the substrate carrier 114. In this example, the base 112 may be attached by any suitable means, for example, using adhesive, threads, an interference fit, or the like.

[0115] Fourth embodiment A fourth embodiment will now be described with reference to Figures 10, 10(a), and 10(b). The aerosol generating device 100 of the fourth embodiment is identical to the aerosol generating device 100 of the first embodiment described with reference to Figures 1 to 6, except as described below, and the same reference numerals are used to refer to similar features. It is also possible for the heating chamber 108 of the fourth embodiment to correspond to the heating chamber 108 of the second embodiment, for example, with a channel 113 provided in the base 112 of the heating chamber 108, except as described below, which forms a further embodiment of the present disclosure.

[0116] The fourth (and further) embodiment of the aerosol generating device 100 has a heating chamber 108 in which the flange 138 is absent.

[0117] By eliminating the flange 138 from the heating chamber 108, the thermal mass of the heating chamber 108 is reduced, at the expense of reducing the structural strength provided by the flange 138. In this embodiment, because there is no flange 138 to grip between the washer 106, the heating chamber 108 is attached to the aerosol generation device 100 in a different manner. More specifically, the heating chamber 108 is sized and held in such a manner to form an interference fit with the inner diameter of the washer 107. This results in a smaller surface area of ​​the heating chamber 108 in contact with the washer 107, which advantageously reduces heat transfer from the heating chamber 108 and improves the overall efficiency of the aerosol generation device 100.

[0118] Fifth embodiment A fifth embodiment will now be described with reference to Figures 11, 11(a), and 11(b). The aerosol generating device 100 of the fifth embodiment is identical to the aerosol generating device 100 of the first embodiment described with reference to Figures 1 to 6, except as described below, and the same reference numerals are used to refer to similar features. It is also possible for the heating chamber 108 of the fifth embodiment to correspond to the heating chamber 108 of the second embodiment, for example, with a channel 113 provided in the base 112 of the heating chamber 108, except as described below, which forms a further embodiment of the present disclosure.

[0119] The fifth (and further) embodiment of the aerosol generating device 100 has a heating chamber 108 in which the protrusions 140 are absent.

[0120] In the fifth embodiment, it is recognized that because the sidewall 126 is relatively thin, a relatively small amount of air within the heating chamber 108 is heated relatively quickly by the heater 124, so it is not necessary to use the protrusions 140 to form a conductive heating path. Any deformation to the thin sidewall 126 could pose a risk of damaging the sidewall 126. In other words, manufacturing a wall without the protrusions 140 can improve the efficiency of the manufacturing process by reducing the number of heating chambers 108 that need to be rejected due to manufacturing errors.

[0121] Definitions and Alternative Embodiments It will be appreciated from the foregoing description that many features of the various embodiments are interchangeable. The present disclosure extends to additional embodiments, including features that combine features from various embodiments together in a manner not specifically recited. For example, the third through fifth embodiments do not have the platform 148 shown in Figures 1 through 6. The inclusion of this platform 148 in the third through fifth embodiments may provide the advantages of the platform 148 described in connection with those figures.

[0122] 9(a) and 9(b), 10(a) and 10(b), and 11(a) and 11(b) show the heating chamber 108 separated from the aerosol generation device 100. This emphasizes that the advantageous features described with respect to the design of the heating chamber 108 are independent of other features of the aerosol inhalation device 100. In particular, there are many uses for the heating chamber 108, not all of which are tied to the vapor inhalation device 100 described herein. Such designs can benefit from a base 112, as described herein, to provide support for the sidewall 126. Such uses are advantageously provided with the heating chamber described herein.

[0123] The term "heater" should be understood to mean any device for outputting sufficient thermal energy to form an aerosol from the aerosol substrate 128. The transfer of thermal energy from the heater 124 to the aerosol substrate 128 can be conductive, convective, radiative, or any combination of these means. As a non-limiting example, a conductive heater may be in direct contact and pressed against the aerosol substrate 128, or may be in contact with a separate component that itself causes heating of the aerosol substrate 128 by conduction, convection, and / or radiation. Convective heating may involve heating a liquid or gas, which then transfers thermal energy (directly or indirectly) to the aerosol substrate.

[0124] Radiative heating includes, but is not limited to, transferring energy to the aerosol substrate 128 by emitting electromagnetic radiation in the ultraviolet, visible, infrared, microwave, or radio frequency portions of the electromagnetic spectrum. The radiation thus emitted may be absorbed directly by the aerosol substrate 128, causing heating, or the radiation may be absorbed by another material, such as a susceptor or fluorescent material, such that the radiation is re-emitted at a different wavelength or spectral weighting. In some cases, the radiation may be absorbed by a material, which then transfers heat to the aerosol substrate 128 by any combination of conduction, convection, and / or radiation.

[0125] The heater may be electrically powered, combustion powered, or powered by any other suitable means. Electrically powered heaters may include resistive track elements (optionally including insulating packaging), inductive heating systems (including, for example, electromagnets and high frequency oscillators), etc. The heater 128 may be configured around the outside of the aerosol substrate 128, may extend partway or completely into the aerosol substrate 128, or any combination thereof.

[0126] The term "temperature sensor" is used to describe an element capable of determining the absolute or relative temperature of a portion of the aerosol-generating device 100. This may include a thermocouple, a thermopile, a thermistor, etc. The temperature sensor may be provided as part of another component or may be a separate component. In some examples, multiple temperature sensors are provided, for example, to monitor the heating of various portions of the aerosol-generating device 100, e.g., to determine a thermal profile.

[0127] The control circuitry 122 is shown throughout as having a single user-operable button 116 for triggering the aerosol generating device 100 to turn on. This keeps the controls simple and reduces the likelihood that a user will misuse or fail to properly control the aerosol generating device 100. However, in some cases, the input controls available to the user may be more complex than this, for example, to control the temperature, e.g., within preset limits, to vary the flavor balance of the vapor, or to switch between, e.g., a power-saving mode and a rapid-heat mode.

[0128] Referring to the above-described embodiments, the aerosol substrate 128 includes tobacco, e.g., in a dried or cured form, and optionally has additional ingredients for flavor or to provide a smoother or more enjoyable experience. In some examples, the aerosol substrate 128, such as tobacco, may be treated with a vaporizer. The vaporizer may improve vapor generation from the aerosol substrate. The vaporizer may include, for example, a polyol, such as glycerol, or a glycol, such as propylene glycol. In some cases, the aerosol substrate may not even include tobacco or nicotine, but instead may include natural or synthetic ingredients for flavoring, volatility, improved smoothness, and / or other satisfying effects. The aerosol substrate 128 may be provided as a solid or paste-type material in shredded, pelleted, powdered, granular, strip, or sheet form, or optionally a combination thereof. Similarly, the aerosol substrate 128 may be liquid or gel. Indeed, in some examples, it may include both solid and liquid / gel portions.

[0129] Thus, the aerosol-generating device 100 may equally be referred to as a "heated tobacco device," a "heated-not-burn tobacco device," a "device for vaporizing tobacco products," etc., and is to be construed as a device suitable for achieving these effects. The features disclosed herein are equally applicable to devices designed to vaporize any aerosol substrate.

[0130] Embodiments of the aerosol generating device 100 are described as being configured to house an aerosol substrate 128 within a pre-packaged substrate carrier 114. The substrate carrier 114 may generally resemble a cigarette, with a tubular region having the aerosol substrate configured in a suitable form. Some designs may also include filters, vapor collection regions, cooling regions, and other structures. An outer layer of paper or other flexible, planar material, such as foil, may also be provided, for example, to hold the aerosol substrate in place, further enhancing the resemblance to a cigarette or the like.

[0131] As used herein, the term "fluid" shall be construed as generically describing a type of non-solid material that is capable of flowing, including, but not limited to, liquids, pastes, gels, powders, etc. Accordingly, a "fluidized material" shall be construed as a material that is inherently fluid or a material that has been modified to behave as a fluid. Fluidization may include, but is not limited to, powdering, dissolving in a solvent, gelling, thickening, thinning, etc.

[0132] As used herein, the term "volatile" refers to a substance that can be readily changed from a solid or liquid state to a gaseous state. As a non-limiting example, a volatile substance may have a boiling or sublimation temperature near room temperature at ambient pressure. Thus, "volatilize" or "volatilize" shall be interpreted to mean to cause (a material) to volatilize and / or to evaporate or disperse into a vapor.

[0133] As used herein, the term "vapour" (or "vapor") means: (i) a form into which a liquid is transformed spontaneously by the action of a sufficient degree of heat; or (ii) liquid / moisture particles suspended in the atmosphere and visible as a cloud of steam / smoke; or (iii) a fluid that fills space like a gas but can be liquefied by pressure alone when below a critical temperature.

[0134] Consistent with this definition, the term "vaporize" (or "vaporize") means: (i) to change into or cause a change into a vapor; and (ii) when a particle changes physical state (i.e., from liquid to vapor). from a body or solid to a gaseous state).

[0135] As used herein, the term "atomize" (or "atomize") shall mean: (i) the conversion (of a substance, especially a liquid) into very small particles or droplets; and (ii) where the particles remain in the same physical state (liquid or solid) as they were before atomization.

[0136] As used herein, the term "aerosol" shall mean a system of particles dispersed in air or gas, such as a mist, fog, or smoke. Accordingly, the term "aerosolize" (or "aerosolize") means to make into an aerosol and / or to disperse as an aerosol. Note that the meaning of aerosol / aerosolize is consistent with each of volatilize, atomize, and vaporize, as defined above. For the avoidance of doubt, aerosol is used to consistently describe a mist or droplets comprising atomized, volatilized, or vaporized particles. Aerosol also includes a mist or droplets comprising any combination of atomized, volatilized, or vaporized particles.

Claims

1. A heating chamber (108) for an aerosol generating device (100), said heating chamber (108) comprising: a first open end (110); a base (112); a sidewall (126) between the open end (110) and the base (112); the base (112) is connected to the sidewall (126) and provides structural support to the sidewall (126); The heating chamber (108), wherein the sidewall (126) has a first thickness and the base (112) has a second thickness greater than the first thickness.

2. 2. The heating chamber of claim 1, wherein the sidewall and the base are formed from the same material, preferably a metal, more preferably the sidewall and the base are stainless steel, even more preferably the stainless steel is a 300 series stainless steel, even more preferably selected from the group including 304 stainless steel, 316 stainless steel, and 321 stainless steel.

3. The heating chamber (108) of claim 1 or 2, wherein the base (112) and the sidewall (126) are formed as a single element, preferably forming a cup-shaped element.

4. The heating chamber (108) of any one of claims 1 to 3, wherein the first thickness is 100 μm or less.

5. The heating chamber (108) of any one of claims 1 to 4, wherein the second thickness is between 200 μm and 500 μm.

6. The heating chamber (108) of any one of claims 1 to 5, wherein the base (112) seals a second end of the side wall (126) opposite the open end (110), and preferably the side wall (126) extends around the entire periphery of the base (112).

7. The heating chamber (108) of any one of claims 1 to 6, comprising a flange portion (138) attached to the open end (110), the flange portion (138) extending radially outward at the open end (110) of the heating chamber (108).

8. The heating chamber (108) of any one of claims 1 to 7, wherein the flange portion (138) extends around the entire periphery of the heating chamber (108).

9. The heating chamber (108) of claim 7 or 8, wherein the flange portion (138) extends obliquely away from the side wall (126).

10. 10. The heating chamber (108) of claim 7, wherein the flange portion (138) comprises a first material and the sidewall (126) comprises a second material, the first material having a lower thermal conductivity than the second material.

11. The heating chamber (108) of any one of claims 1 to 10, wherein the sidewall (126) comprises a material having a thermal conductivity of 50 W / mK or less.

12. The heating chamber (108) of any one of claims 1 to 11, further comprising a plurality of protrusions (140) formed on an interior surface of the sidewall (126).

13. The heating chamber (108) of claim 12, wherein the protrusion (140) is formed by recessing an exterior surface of the sidewall (126).

14. The heating chamber (108) of any one of claims 1 to 13, further comprising a platform (148) on an interior surface of the base (112).

15. The heating chamber (108) of claim 14, wherein the platform (148) is formed by a depression in an outer surface of the base (112).

16. The heating chamber (108) of any one of claims 1 to 15, wherein the heating chamber (108) is a deep-drawn product.

17. An aerosol generating device (100), comprising: a power source (120); A heating chamber (108) according to any one of claims 1 to 16, a heater (124) configured to supply heat to the heating chamber (108); a control circuit (122) configured to control the supply of power from the power source (120) to the heater (124).

18. 18. The aerosol generating device (100) of claim 17, wherein the heater (124) is disposed on an outer surface of the side wall (126).

19. 18. The aerosol generating device (100) of claim 17, wherein the heater (124) is located adjacent to an exterior surface of the sidewall (126).

20. The aerosol generating device (100) of any one of claims 17 to 19, wherein the heating chamber (108) is removable from the aerosol generating device (100).

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