Heating assembly with vacuum insulation

Abstract

A heating assembly (10) for an aerosol-generating device (8) is disclosed. The heating assembly (10) comprises a vacuum insulation (12) having an inner wall (14) and an outer wall (20) with a vacuum sealed therebetween, the inner wall (14) of the vacuum insulation defining a cavity (26) with an opening (28), the cavity (26) extending from a base (30) of the inner wall (14) to the opening (28), the cavity (26) configured to receive an aerosol-generating substrate (32) through the opening (28). A heater (34) is located within the vacuum on the outer surface (18) of the inner wall (14) of the vacuum insulation (12), the heater (34) configured to heat the aerosol-generating substrate (32) received in the cavity (26) by thermal conduction to generate an aerosol. The heater (34) is disposed on a first portion (36) of the outer surface (18) of the inner wall (14) to at least partially surround the cavity (26), the first portion (36) of the inner wall (14) having a thickness less than at least one of a second portion (38) of the inner wall (14) between the first portion (36) and the opening (28) and a third portion (40) of the inner wall (14) between the first portion (36) and the base (30).

Description

[Technical Field]

[0001] The present disclosure relates to a heating assembly for an aerosol generating device, a method for manufacturing a heating assembly for an aerosol generating device, and an aerosol generating device including a heating assembly. The disclosure is particularly applicable to portable aerosol generating devices that may be self-contained and low-temperature. Such devices may heat tobacco or other suitable aerosol substrate material 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-reducing or risk-modifying devices (also known as vaporizers) has grown rapidly in recent years as an aid to assisting regular smokers who wish to quit using traditional tobacco products, such as cigarettes, cigars, cigarillos, and roll-up cigarettes. A variety of devices and systems are available that heat or warm an aerosolizable substrate, as opposed to burning tobacco in traditional tobacco products.

[0003] Commonly available risk reduction or risk modification devices are substrate-heated aerosol generating devices or heat-and-burn devices. These types of devices generate an aerosol or vapor by heating an aerosol substrate, i.e., a consumable, typically containing 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 components desired by the user but is free of the undesirable by-products of combustion. Additionally, aerosols generated by heating tobacco or other aerosolizable material typically do not contain the burnt or bitter taste that can result from combustion, which can be unpleasant to users.

[0004] Within such aerosol generating devices, it is desirable to improve the efficiency of the heating operation so that the battery life of the device can be extended. To this end, vacuum insulation has been implemented within aerosol generating devices to insulate the cavity in which the aerosol substrate is heated, thereby limiting heat loss to the external environment.

[0005] However, during heating of the vacuum insulation in the aerosol generating device, thermal energy from the heater is conducted along the solid inner wall of the vacuum insulation, which often results in an unfavorable distribution of heat to the aerosol substrate, promoting inconsistent and inefficient aerosol generation. Summary of the Invention [Problem to be solved by the invention]

[0006] The purpose of the present invention is to address this problem. [Means for solving the problem]

[0007] According to a first aspect of the present invention, there is provided a heating assembly for an aerosol-generating device, comprising: a vacuum insulation material having an inner wall and an outer wall with a vacuum sealed therebetween, the inner wall of the vacuum insulation material defining a cavity with an opening, the cavity extending from a base of the inner wall to the opening, the cavity configured to receive an aerosol-generating substrate through the opening; and a heater located within the vacuum on an outer surface of the inner wall of the vacuum insulation material, the heater configured to heat the aerosol-generating substrate received in the cavity by thermal conduction to generate an aerosol, wherein a first portion of the inner wall adjacent the heater has a thickness less than at least one of a second portion of the inner wall between the first portion and the opening and a third portion of the inner wall between the first portion and the base.

[0008] In this manner, the thickness of the inner wall of the vacuum insulation varies such that a first portion of the inner wall has a higher thermal conductance than a second and / or third portion of the inner wall. In other words, the thermal conductance of the inner wall decreases toward at least one of the opening and the base of the inner wall. This minimizes the rate of heat transfer from the heater toward the opening and / or the base, thereby substantially decreasing the rate of thermal energy transfer between the inner wall of the vacuum insulation and the aerosol-generating substrate received within the cavity toward the ends of the aerosol-generating substrate.

[0009] As will be appreciated by those skilled in the art, to optimize the efficiency of aerosol generation, it is preferable to concentrate heating of the aerosol-generating substrate away from its ends (i.e., concentrate heating in the region of the aerosol-generating substrate adjacent to the heater). Therefore, it is undesirable for thermal energy to be conducted along the inner wall of the vacuum insulation away from the heater toward either end of the cavity of the vacuum insulation, because this would result in increased heating of the ends of the aerosol-generating substrate. Thus, by providing a thicker portion of the inner wall between the heater and the opening (i.e., the second portion) and / or a thicker portion of the inner wall between the heater and the base (i.e., the third portion), heat conduction from the heater toward the base and / or the opening is slowed. This means that the rate of heat transfer between the first portion of the inner wall of the vacuum insulation and the aerosol-generating substrate is increased, while the rate of heat transfer between the portions of the inner wall of the vacuum insulation away from the heater (i.e., the second portion, the third portion, and optionally, further portions of the inner wall beyond the second and third portions) is decreased. Thus, the consistency and efficiency of aerosol generation is improved.

[0010] It will be understood that the thickness of the first, second and third portions of the vacuum inner wall refers to the (vertical) distance between the inner surface of the inner wall and the outer surface of the inner wall.

[0011] It will be understood that the heater being adjacent to the first portion of the inner wall means that the heater is radially adjacent to the first portion of the inner wall and the vacuum insulation, in other words, the heater is located on the outer surface of the inner wall such that the heater is at least partially coextensive with the first portion of the inner wall.

[0012] The inner surface of the inner wall preferably has a continuous (i.e., planar) surface, while the outer surface of the inner wall preferably has a discontinuous (i.e., stepped) surface. Thus, the change in thickness of the inner wall is provided by the change in surface height of the outer surface of the inner wall. This means that the thermal conductance of the inner wall of the vacuum insulation material can be changed without changing the internal dimensions of the cavity.

[0013] The ratio of the thickness of the first portion to the thickness of the second portion and / or the third portion may be 1:1.5 to 1:3, for example, 1:2 or 1:2.5. For example, the thickness of the first portion may be 60 μm, and the thickness of the second portion and / or the third portion may be 120 μm, i.e., a ratio of 1:2. In another embodiment, the thickness of the first portion may be 80 μm, and the thickness of the second portion and / or the third portion may be 120 μm, i.e., a ratio of 1:1.5. In another embodiment, the thickness of the first portion may be 40 μm to 80 μm, and the thickness of the second portion and / or the third portion may be 80 μm to 120 μm.

[0014] Preferably, the first portion of the inner wall has a thickness that is less than the second portion of the inner wall, thereby reducing the rate of heat transfer towards the opening of the cavity so as to also reduce the rate of heat transfer between the inner wall of the vacuum insulation and the mouth end of the aerosol-generating substrate.

[0015] Preferably, the first portion of the inner wall has a thickness less than the third portion of the inner wall, thereby reducing the rate of heat transfer towards the base of the cavity, such that the rate of heat transfer between the inner wall of the vacuum insulation and the insertion end of the aerosol-generating substrate is also reduced.

[0016] Preferably, the first portion of the inner wall has a thickness less than the second portion of the inner wall and the third portion of the inner wall, thereby reducing the rate of heat transfer toward both the base and the opening, and thereby reducing the rate of heat transfer between the inner wall of the vacuum insulation and both the mouth end and insertion end of the aerosol-generating substrate.

[0017] Preferably, the thickness of the inner wall is smallest along the first portion of the inner wall. In this way, the rate of heat transfer from the heater to the first portion of the inner wall of the vacuum insulation is maximized, thereby concentrating the supply of thermal energy from the inner wall of the vacuum insulation away from the mouth end and insertion end of the aerosol-generating substrate, i.e., on the region of the aerosol-generating substrate adjacent the heater. Thus, the efficiency and consistency of aerosol generation are optimized.

[0018] Preferably, the thickness of the inner wall is greatest along the second portion of the inner wall, in this way minimizing the rate of heat transfer from the heater along the inner wall of the vacuum insulation toward the opening, thereby minimizing the transfer of thermal energy from the inner wall of the vacuum insulation to the mouth end of the aerosol-generating substrate.

[0019] Preferably, the thickness of the inner wall is greatest along a third portion of the inner wall, in this way minimizing the rate of heat transfer from the heater toward the base along the inner wall of the vacuum insulation, thereby minimizing the transfer of thermal energy from the inner wall of the vacuum insulation to the insertion end of the aerosol-generating substrate.

[0020] Preferably, the cavity is tubular.

[0021] Preferably, the heater is printed or coated onto the outer surface of the inner wall of the vacuum insulation, thus providing reliable thermal contact between the heater and the inner wall of the vacuum insulation.

[0022] According to a second aspect of the present invention, there is provided a method of manufacturing a heating assembly for an aerosol generating device, comprising: providing an outer wall; providing an inner wall shaped to define a cavity having an opening, the cavity extending from a base of the inner wall to the opening, the inner wall having a first portion, a second portion, and a third portion, the first portion being located between the second portion and the third portion, and the first portion having a thickness smaller than that of the second portion and / or the third portion; providing a heater on an outer surface of the inner wall adjacent to the first portion; bonding the inner wall to the outer wall to form a sealed space between the outer wall and the inner wall in which the heater is located; and forming a vacuum in the sealed space between the outer wall and the inner wall.

[0023] Preferably, providing the inner wall comprises die-cutting a sheet of material to form an inner wall having a varying thickness, thus improving the ease of manufacturing the aerosol generating device.

[0024] Preferably, providing a heater on the outer surface of the inner wall adjacent to the first portion includes printing or coating the heater on the outer surface of the inner wall adjacent to the first portion. In this way, reliable thermal contact is provided between the heater and the inner wall of the vacuum insulation. Furthermore, the ease of manufacturing the aerosol generating device is improved.

[0025] Embodiments of the invention will now be described, by way of example, with reference to the drawings, in which: [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a perspective view of an aerosol generating device including a heating assembly according to one embodiment of the present invention; FIG. [Figure 2] 1 is a schematic perspective view of a heating assembly according to one embodiment of the present invention; [Figure 3] 3 is a cross-sectional schematic view of the heating assembly of FIG. 2. [Figure 4] FIG. 2 is a flow diagram illustrating method steps for manufacturing a heating assembly according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] As described herein, a vapor is generally understood to refer to a substance that is in the gas phase below its critical temperature, meaning that the vapor can be condensed into a liquid by increasing the pressure without decreasing the temperature, while an aerosol is fine solid particles or liquid droplets suspended in air or another gas. However, it should be noted that the terms "aerosol" and "vapor" can be used interchangeably herein, particularly with respect to the form of inhalable medium produced for inhalation by a user.

[0028] FIG. 1 illustrates an aerosol generating device 8 according to an embodiment of the present invention. The aerosol generating device 8 is shown in an assembled configuration with exemplary internal components visible. The aerosol generating device 8 is a heat-non-combustion device, which may also be referred to as a tobacco vapor device, and includes a heating assembly 10 configured to receive an aerosol-generating material, e.g., an aerosol substrate such as a tobacco rod. The aerosol generating device 8 may include a power source, such as a battery, and control circuitry for controlling the supply of power from the power source to the heating assembly 10. The heating assembly 10 is operable to heat, rather than burn, the rod of aerosol-generating material to generate a vapor or aerosol for inhalation by a user. Of course, those skilled in the art will understand that the aerosol generating device 8 illustrated in FIG. 1 is merely an exemplary aerosol generating device according to the present invention. Other types and configurations of tobacco vapor products, vaporizers, or e-cigarettes may also be used as aerosol generating devices according to the present invention.

[0029] Figure 2 shows a perspective view of a heating assembly 10 according to one embodiment of the present invention. Similarly, Figure 3 shows a simplified cross-sectional view of the heating assembly 10.

[0030] The heating assembly 10 includes a vacuum insulation material 12 having an inner wall 14 and an outer wall 20 with a vacuum sealed therebetween. The vacuum insulation material 12 extends from a first end 11 to a second end 13; i.e., the vacuum insulation material 12 is elongated and defines a longitudinal axis. The vacuum insulation material 12 defines a cavity 26 that may receive an aerosol-generating substrate 32. Specifically, the top 15 of the vacuum insulation material 12 at the first end 11 has an opening 28 through which the aerosol-generating substrate 32 may be inserted into the cavity 26. The vacuum insulation material 12 may therefore be referred to as cup-shaped.

[0031] The vacuum insulation material 12 has a generally oval or circular cross-section when viewed along one of its ends 11, 13 parallel to its longitudinal axis. In particular, in the illustrated embodiment, the vacuum insulation material 12 is generally cylindrical. However, in alternative embodiments, the vacuum insulation material 12 may be formed with other types of cross-sectional shapes, such as a shape that is generally square or polygonal.

[0032] The inner wall 14 of the vacuum insulation 12 is tubular, e.g., generally cylindrical, and has an outer (e.g., circumferential) surface 18 and an inner (e.g., circumferential) surface 16. The inner wall 14 further comprises a base 30. The outer wall 20 is tubular, e.g., generally cylindrical, and has an outer (e.g., circumferential) surface 24 and an inner (e.g., circumferential) surface 22. The outer wall 20 comprises a base 17 at the second end 13 of the vacuum insulation 12.

[0033] The inner wall 14 and the outer wall 20 are radially spaced apart from one another to define an enclosed space in which a vacuum is formed therebetween. Specifically, in the illustrated embodiment, the inner wall 14 and the outer wall 20 are formed as concentric cylinders that are joined at the first end 11 of the vacuum insulation material 12. In a first example, the top portion 15 of the vacuum insulation material 12 may be an integral part of the outer wall 20 that is attached to the inner wall 14 at the first end 11. In a second example, the top portion 15 of the vacuum insulation material 12 may be an integral part of the inner wall 14 that is attached to the outer wall 20 at the first end 11. In a third example, the top portion 15 of the vacuum insulation material 12 may be an additional component that joins the inner wall 14 and the outer wall 20 at the first end 11.

[0034] Those skilled in the art will understand that the term "vacuum" refers to a space in which the pressure is significantly less than atmospheric pressure due to the removal of free matter, particularly air. The quality of the vacuum formed between the inner wall 14 and the outer wall 20 may be a low vacuum, a medium vacuum, or a high vacuum.

[0035] The inner wall 14 of the vacuum insulation material 12 defines a cavity 26 that may receive an aerosol-generating substrate 32. In particular, the cavity 26 defined by the inner wall 14 of the vacuum insulation material 12 is tubular (e.g., cylindrical) and extends from a base 30 to an opening 28. In this manner, an aerosol-generating substrate 32 in the form of an elongated rod (e.g., cylinder) may be inserted into the cavity 26 through the opening 28 such that the aerosol-generating substrate 32 interfaces with the inner surface 16 and the base 30 of the inner wall 14. Except for a portion of the aerosol-generating substrate 32 that protrudes through the opening 28 and is received in the user's mouth, the vacuum insulation material 12 completely surrounds the aerosol-generating substrate 32, thus maximizing the effectiveness of the insulation. Those skilled in the art will understand that the cavity 26 is a blind hole, not a through hole.

[0036] Typically, the aerosol-generating substrate 32 is a disposable, replaceable item that may, for example, contain tobacco as the aerosol-generating material (known as a "consumable" or heat-and-burn stick). The aerosol-generating substrate 32 has a mouth end 44 and an opposite insertion end 46.

[0037] The heating assembly 10 further includes a heater 34 disposed on the outer surface 18 of the inner wall 14 of the vacuum insulation 12. That is, the heater 34 is located between the inner wall 14 and the outer wall 20 of the vacuum insulation 12 within the vacuum. The heater 34 is configured to heat the inner wall 14 of the vacuum insulation 12 by conduction, such that the inner wall 14 heats the aerosol-generating substrate 32 and the air inside the cavity 26 by conduction and radiation. The heater 34 may be powered by a battery or any other power source provided on the aerosol-generating device. For example, the heater 34 may be connectable via an electrical connector 42 to the aerosol-generating device 8, which includes a control circuit and a power source, such as a battery. In this manner, an electrical circuit may be formed between the power source and the heater 34 via the electrical connector 42. In use, the heater 34 receives power from the power source of the aerosol-generating device 8 and generates heat by Joule heating. The heat is transferred through the interior wall 14 to the aerosol-generating substrate 32 received within the cavity 26 to generate an aerosol for inhalation by the user. In Figures 2 and 3, an electrical connector 42 is shown as connecting to the base 30 of the interior wall 14. However, those skilled in the art will recognize that the type and location of the electrical connector 42 may be varied and that the heater 34 may be supplied with electricity by a variety of alternative means.

[0038] The heater 34 is a resistive heating element that generates heat through resistive heating (also known as Joule heating). The heater 34 includes a heating track (e.g., a wave-like heating pattern) that at least partially surrounds the cavity 26 on the outer surface 18 of the inner wall 14 of the vacuum insulation 12. Specifically, the heating track is wrapped circumferentially around the inner wall 14 of the vacuum insulation 12, preferably around the entire circumference of the cavity 26. Advantageously, surrounding the cavity 26 substantially around its entire circumference results in faster or more uniform heating of the aerosol-generating substrate 32. Of course, those skilled in the art will appreciate that the specific shape and configuration of the heater 34 may vary. For example, the heater 34 may include a heating sheet that partially or completely surrounds the outer surface 18 of the inner wall 14 of the vacuum insulation 12.

[0039] The heater 34 may be printed, coated, or otherwise attached onto the outer surface 18 of the inner wall 14 of the vacuum insulation 12. The heater 34 may thus provide "trace heating" to the cavity 26.

[0040] The heater 34 may comprise a metal (e.g., nichrome, kanthal, or cupronickel), ceramic, or any other suitable resistive heating material. As will be appreciated by those skilled in the art, the heater 34 is not limited to a resistive heating element, and the heater 34 may be of various types. For example, the heater 34 may be an induction heater powered by a coil surrounding the vacuum insulation 12.

[0041] 3, the thickness of the inner wall 14 of the vacuum insulation 12 varies along the cavity 26, i.e., in a direction defined between the opening 28 and the base 30. The inner wall 14 is divided into multiple sections, including a first section 36, a second section 38, and a third section 40.

[0042] The first portion 36 is located adjacent to the heater 34. That is, the first portion 36 is a circumferential section of the inner wall 14 that is aligned with the heater 34. In the illustrated embodiment, the first portion 36 is coextensive with the heater 34. However, in alternative embodiments, the first portion 36 may extend beyond the heater 34 along the length of the cavity 26, or the heater 34 may extend beyond the first portion 36 along the length of the cavity 26.

[0043] The second portion 38 is located between the first portion 36 and the opening 28. That is, the second portion 38 is a circumferential section of the inner wall 14 that is disposed between the heater 34 and the opening 28. In the illustrated embodiment, the second portion 38 terminates at the opening 28, that is, the second portion 38 extends from the first portion 36 to the opening 28. However, in alternative embodiments, the second portion 38 may not extend all the way to the opening 28, but instead may terminate before the opening 28. In this case, the inner wall 14 may include one or more additional portions located between the second portion 38 and the opening 28. The additional portions may have a thickness that is greater or less than the thickness of the second portion 38 and / or the first portion 36.

[0044] The third portion 40 is located between the first portion 36 and the base 30. That is, the third portion 40 is a circumferential section of the inner wall 14 that is disposed between the heater 34 and the base 30. In the illustrated embodiment, the third portion 40 terminates at the base 30, that is, the third portion 40 extends from the first portion 36 to the base 30. However, in alternative embodiments, the third portion 40 may not extend to the base 30, but instead may terminate before the base 30. In this case, the inner wall 14 may include one or more additional portions located between the third portion 40 and the base 30. The additional portions may have a thickness that is greater or less than the thickness of the third portion 40 and / or the first portion 36.

[0045] The thickness of each of the second and third portions 38, 40 is greater than the thickness of the first portion 36. Because thermal conductance is inversely proportional to thickness, a greater thickness results in a smaller heat flux. Therefore, increasing the thickness of the second and third portions 38, 40 slows the heat flux toward the opening 28 and base 30, respectively. Advantageously, this means that the temperature of the inner wall 14 of the vacuum insulation 12 is suppressed toward the opening 28 and base 30. Consequently, the regions of the aerosol-generating substrate 32 adjacent to the opening 28 and base 30 (i.e., the mouth end 44 and the insertion end 46) receive significantly less heat energy than the regions of the aerosol-generating substrate 32 between the mouth end 44 and the insertion end 46, i.e., the regions of the aerosol-generating substrate 32 adjacent to the heater 34 or first portion 36. Reducing the heat energy delivered toward the mouth end 44 and the insertion end 46 of the aerosol-generating substrate results in more efficient and consistent aerosol generation.

[0046] The ratio of the thickness of the first portion 36 to the thickness of the second portion 38 and / or the third portion 40 may be 1:1.5 to 1:3. For example, the thickness of the first portion 36 may be 60 μm, and the thickness of the second portion 38 and / or the third portion 40 may be 120 μm, i.e., a ratio of 1:2. In other embodiments, the thickness of the first portion 36 may be 40 μm to 80 μm, and the thickness of the second portion 38 and / or the third portion 40 may be 80 μm to 120 μm.

[0047] The thickness of the inner wall 14 of the vacuum insulation 12 refers to the (vertical) distance between the inner surface 16 of the inner wall 14 and the outer surface 18 of the inner wall 14. As shown in Figure 3, the inner surface 16 of the inner wall 14 forms a continuous surface, i.e., the inner surface 16 (as a whole) of the inner wall 14 follows the circumferential surface, thereby having a consistent surface topography.

[0048] Thus, the variation in thickness of the inner wall 14 is provided by the outer surface 18 of the inner wall 14, which is formed as a stepped surface. That is, the outer surface 18 exhibits a discontinuous surface topography along the length of the inner wall 14. In particular, while the first portion 36, the second portion 38, and the third portion 40 each individually define a continuous outer surface (e.g., a circumferential surface), the surface height of the outer surface 18 relative to the cavity 26 along the first portion 36 is discontinuous compared to the surface height of the outer surface 18 relative to the cavity 26 along the second portion 38 and the third portion 40. Advantageously, this arrangement means that a constant internal interface is provided for heat transfer from the inner wall 14 to the aerosol-generating substrate 32 received within the cavity 26, while also providing a varying thermal conductance along the inner wall 14.

[0049] In the embodiment shown, the second portion 38 and the third portion 40 are both thicker than the first portion 36. However, in alternative embodiments, only the second portion 38 or the third portion 40 may be thicker than the first portion 36, or the inner wall 14 may be comprised of the first portion 36 and either the second portion 38 or the third portion 40. Furthermore, in the embodiment shown, the second portion 38 and the third portion 40 have the same thickness. However, in alternative embodiments, the second portion 38 may be thicker than the third portion 40, or the third portion 40 may be thicker than the second portion 38. Furthermore, in other embodiments, the second portion 38 and / or the third portion 40 may increase in thickness toward the opening 28 and / or the base 30, respectively. That is, the outer surface 18 of the inner wall 14 may be inclined relative to the inner surface 16 of the inner wall 14 along the second portion 38 and / or the third portion 40, thereby decreasing the thermal conductance of the inner wall 14 toward the opening 28 and / or the base 30.

[0050] The inner wall 14 of the vacuum insulation 12 may comprise any suitable material having suitable properties for transferring heat from the heater 34 into the cavity 26, such as stainless steel or other metals, metal alloys, or ceramics. Examples of suitable materials for the outer wall 20 include stainless steel and / or plastics such as polyetheretherketone (PEEK).

[0051] FIG. 4 shows a flow chart that is a method 60 of manufacturing a heating assembly 10 according to one embodiment of the present invention.

[0052] The method 60 begins at step 62 where the exterior wall 20 is provided.

[0053] In step 64, the inner wall 14 is provided. The inner wall 14 is shaped to define a cavity 26 having an opening 28, the cavity 26 extending from a base 30 of the inner wall 14 to the opening 28. The inner wall 14 includes a first portion 36, a second portion 38, and a third portion 40, where the first portion 36 is located between the second portion 38 and the third portion 40, and the first portion 36 has a thickness less than the second portion 38 and / or the third portion 40.

[0054] Optionally, the interior wall 14 may be formed by a stamping (or pressing) process. In particular, the interior wall 14 may be formed by stamping a sheet of material to form the interior wall 14 including a first portion 36 having a thickness less than the second portion 38 and / or the third portion 40. Stamping involves placing the sheet of material in a stamping press and using a die to form the sheet of material into the interior wall 14. A die is a tool that is pressed into the sheet of material such that the sheet of material takes the shape of the die.

[0055] In step 66, a heater 34 is provided on the outer surface 18 of the inner wall 14 adjacent to the first portion 36. For example, the heater 34 may be printed, coated, or otherwise secured to the outer surface 18 of the inner wall 14 parallel to the first portion 36.

[0056] In step 68, the inner wall 14 is bonded to the outer wall 20 to form an enclosed space between the outer wall 20 and the inner wall 14 in which the heater 34 is located.

[0057] Finally, in step 70, a vacuum is formed in the enclosed space between the outer wall 20 and the inner wall 14.

[0058] Those skilled in the art will appreciate that the shapes, properties, and configurations of the features discussed with reference to FIGS. 2 and 3 apply equally to the features discussed with reference to method 60.

Claims

1. 1. A heating assembly for an aerosol generating device, comprising: a vacuum insulation material having an inner wall and an outer wall with a vacuum sealed therebetween, the inner wall of the vacuum insulation material defining a cavity having an opening, the cavity extending from a base of the inner wall to the opening, the cavity configured to receive an aerosol-generating substrate through the opening; a heater located within the vacuum on an outer surface of the inner wall of the vacuum insulation, the heater configured to heat the aerosol-generating substrate received in the cavity by thermal conduction to generate an aerosol; and Equipped with the heater is positioned on a first portion of the outer surface of the inner wall to at least partially surround the cavity; the first portion of the inner wall has a thickness less than at least one of a second portion of the inner wall between the first portion and the opening and a third portion of the inner wall between the first portion and the base. Heating assembly.

2. The heating assembly of claim 1 , wherein the first portion of the inner wall has a thickness that is less than the second portion of the inner wall.

3. The heating assembly of claim 1 or 2, wherein the first portion of the inner wall has a thickness that is less than the third portion of the inner wall.

4. The heating assembly of claim 1 , wherein the first portion of the inner wall has a thickness that is less than the second portion of the inner wall and the third portion of the inner wall.

5. The heating assembly of claim 1 , wherein the thickness of the inner wall is smallest along the first portion of the inner wall.

6. The heating assembly of claim 1 , wherein the thickness of the inner wall is greatest along the second portion of the inner wall.

7. The heating assembly of claim 1 , wherein the thickness of the inner wall is greatest along the third portion of the inner wall.

8. The heating assembly of claim 1 , wherein the cavity is tubular.

9. The heating assembly of claim 1 , wherein the heater is printed or coated onto the outer surface of the inner wall of the vacuum insulation.

10. An aerosol generating device comprising a heating assembly according to any one of claims 1 to 9.

11. 1. A method of manufacturing a heating assembly for an aerosol generating device, comprising: Providing exterior walls; providing an inner wall shaped to define a cavity having an opening, the cavity extending from a base of the inner wall to the opening, the inner wall comprising a first portion, a second portion, and a third portion, the first portion being located between the second portion and the third portion, and the first portion having a thickness less than the second portion and / or the third portion; providing a heater on an outer surface of the inner wall, the heater being positioned on the first portion of the outer surface of the inner wall to at least partially surround the cavity; coupling the inner wall to the outer wall to form an enclosed space between the outer wall and the inner wall, the heater being located within the enclosed space; forming a vacuum in the enclosed space between the outer wall and the inner wall; A method comprising:

12. 12. The method of claim 11, wherein providing the interior wall comprises stamping a sheet of material to form the interior wall having a varying thickness.

13. 13. The method of claim 11 or 12, wherein providing the heater on the outer surface of the inner wall adjacent the first portion comprises printing or coating the heater on the outer surface of the inner wall adjacent the first portion.

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