Aerosol generating device having a thermally insulated chamber

Abstract

An aerosol generating device (100) is disclosed that includes an insulated chamber, which may be a vacuum chamber (102), defined between an inner wall (104) and an outer wall (106). A heating chamber (108) is defined radially inward of the inner wall. The device also includes a heater (110) on an outer surface of the inner wall. The heater is electrically connected to a first region (112) of the outer wall and a second region (113) of the outer wall. The first and second regions are electrically insulated from one another by an insulator (118).

Description

[Technical field]

[0001] The present invention relates to an aerosol generating device, in particular to an aerosol generating device having a heater disposed within an insulated chamber, which may be a vacuum chamber. [Background technology]

[0002] It is a developing area of ​​interest to produce electronic cigarettes that heat but do not burn a solid or semi-solid aerosol-forming substrate, including tobacco. These devices typically receive a rod of tobacco in a heating chamber. The rod is heated to release an aerosol that can be inhaled by the user. One problem with these devices is that the heater that provides heat to the heating chamber can also undesirably heat the rest of the device. In compact devices, this can be a disadvantage, as the temperature of the exterior surface of the device held by the user can become unacceptably high. To mitigate these effects, some aerosol generating devices include a chamber that allows the heater to be spaced from the exterior surface. This can provide thermal isolation between the heating chamber and the exterior surface held by the user. Summary of the Invention [Problem to be solved by the invention]

[0003] There is a need to produce aerosol generating devices, such as electronic cigarettes, that include chambers with simplified structures. It is an object of the present invention to provide an aerosol generating device that addresses these demands. [Means for solving the problem]

[0004] According to one aspect of the present invention, an aerosol generating apparatus is provided, the aerosol generating apparatus including a chamber defined between an inner wall and an outer wall, the heating chamber capable of receiving an aerosol-forming substrate being defined radially inward of the inner wall, and a heater on an outer surface of the inner wall, the heater being electrically connected to a first region of the outer wall and a second region of the outer wall, the first and second regions being electrically insulated from each other.

[0005] In this way, the structure of the aerosol generating device can be simplified and the size of the aerosol generating device can be reduced. This can be achieved because the outer wall of the chamber serves a dual function by surrounding the heater and providing an electrical connection to the heater. In this manner, there is no need to provide a separate electrical terminal through the outer wall of the chamber. This approach can also improve the ease of assembly, since the heater on the outer surface of the inner wall can be easily electrically connected to the respective first and second regions on the outer wall.

[0006] Preferably, the chamber is a vacuum chamber. In this way, the outer wall, and therefore the exterior of the device, can be better insulated from the heat from the heater. As will be appreciated by those skilled in the art, various materials can be provided within the chamber to provide insulation. This includes, but is not limited to, powdered or fibrous materials such as aerogel, or air.

[0007] Preferably, the heater and a first region of the outer wall are biased towards one another. The heater and a second region of the outer wall may also be biased towards one another. This may be achieved by providing a spring loaded electrical connection. Optionally, a biased electrical connector may be provided which is urged towards the outer wall and / or the heater.

[0008] In this manner, ease of assembly of the device is further increased since electrical connections are more easily established in the limited space within the chamber. Furthermore, less stress is placed on potentially fragile device components, such as heaters, during formation of the electrical connections between the first and second regions and during general use by a user. Furthermore, electrical connections can be more reliably established, thereby reducing the likelihood of the connections coming loose after a period of use or during rough handling.

[0009] Preferably, the outer wall includes a side wall and a bottom wall. The outer wall may be substantially U-shaped or cup-shaped with a substantially cylindrical portion having a side wall and a base portion having a bottom wall. In this manner, the device may be formed to be convenient for use as an e-cigarette. The inner wall may be nested within the outer wall and may have a similar shape.

[0010] In one configuration, the first region of the outer wall can be on the side wall and the second region of the outer wall can be on the bottom wall. In an alternative arrangement, the first region of the outer wall can be on the side wall and the second region of the outer wall can be on the side wall. In yet another embodiment, the first region of the outer wall can be on the bottom wall and the second region of the outer wall can be on the bottom wall.

[0011] Preferably, the first and second regions are electrically insulated from each other by an insulator. In this way, the first and second electrically active regions can be prevented from electrically contacting each other and shorting the device. The insulator can be, for example, a gasket or an electrical sealant. The insulator can be arranged circumferentially on the bottom wall or in the side wall, and the insulator can also be arranged on the side wall and the bottom wall. The insulator can define a boundary between the first region of the outer wall and the second region of the outer wall.

[0012] The device may be used to heat multiple aerosol-forming substrates that may be removed and replaced as they wear out. The aerosol-forming substrate may include a tobacco substrate, which may be a solid or semi-solid substrate that can be heated without burning. In an alternative scenario, the aerosol-forming substrate may include other types of substrates, such as a vaporizable liquid substrate held in a reservoir. The inner wall may also be substantially cup-shaped. The heating chamber may be substantially cylindrical with a substantially circular cross-sectional shape. The aerosol-forming substrate may be surrounded by the sidewall of the heating chamber and may abut against the bottom wall of the heating chamber during heating.

[0013] Preferably, the first region and the second region are each electrically connected to a power source. In this manner, power can be provided to the components of the device via a power source, such as a battery. The battery can be a rechargeable battery or a single-use battery.

[0014] Preferably, the heater is a resistive electric heating element. In this manner, the heater can be arranged in various configurations on the outer surface of the inner wall to provide the appropriate heating characteristics to the aerosol-forming substrate. The heating element can be configured to operate in multiple user-selectable heating behaviors.

[0015] Preferably, the nonlinear path is provided along the surface of the insulator outside the chamber between the first region of the outer wall and the second region of the outer wall. In this way, the creepage distance between the first region of the outer wall and the second region of the outer wall can be increased along the nonlinear path, thereby reducing the possibility of a short circuit occurring between the first region of the outer wall and the second region of the outer wall. The nonlinear path can include straight portions and vertices. The nonlinear path can also or alternatively include curved portions.

[0016] Preferably, the insulator protrudes from the outer wall outside the chamber. This can increase the distance that electrons need to travel along the surface of the insulator from the first region to the second region, thereby reducing the risk of short circuits. This can be particularly useful when the insulator is very thin and the separation between the first and second regions is very small. In some embodiments, the insulator can protrude from the outer wall inside the chamber, but protrusions outside the chamber, where air and other materials can support a flow of electrons that can cause short circuits, are believed to be more important. The insulator can be configured with a cross section of any shape that extends outward from the outer wall outside the chamber. The insulator can be configured to surround a portion of either the first region or the second region of the outer wall. The insulator can be further configured to surround a portion of the side wall or the bottom wall.

[0017] Preferably, the first region of the outer wall is clamped by the second region of the outer wall. More preferably, the second region of the outer wall includes a groove into which the first region of the outer wall can be received to be clamped in place. In this way, a mechanical seal can be provided between the first region of the outer wall and the second region of the outer wall by the insulator. The insulator can provide a mechanical seal to the outer wall to form a chamber, while at the same time providing the function of electrically insulating the first and second regions from each other.

[0018] Preferably, the first region of the outer wall is recessed from the second region of the outer wall. In this way, the path length along the surface of the insulator inside and outside the chamber between the first and second regions can be increased. The distance that electrons must travel along the surface of the insulator from the first region to the second region is increased, thereby reducing the risk of short circuits.

[0019] According to another aspect of the present invention, there is provided a method of manufacturing an aerosol generating device, the method including: forming a chamber between an inner wall and an outer wall, and forming a heating chamber capable of receiving an aerosol-forming substrate, the heating chamber being defined radially inward of the inner wall; providing a heater on an outer surface of the inner wall; creating electrical connections between the heater and a first region of the outer wall and between the heater and a second region of the outer wall; and electrically insulating the first and second regions from each other. [Brief description of the drawings]

[0020] Embodiments of the invention will now be described, by way of example only, with reference to the following drawings, in which:

[0021] [Figure 1] 1 is a schematic cross-sectional view of an apparatus according to one embodiment of the present invention. [Diagram 2] 1 is a schematic cross-sectional view of an apparatus in an alternative embodiment of the present invention. [Diagram 3] 1 is a schematic cross-sectional view of an apparatus in an alternative embodiment of the present invention. [Figure 4a-4c] 1 is a schematic cross-sectional view of an apparatus in an alternative embodiment of the present invention. [Diagram 5] 1 is a schematic cross-sectional view of an apparatus in an alternative embodiment of the present invention. [Figure 6] 1 is a schematic cross-sectional view of an apparatus in an alternative embodiment of the present invention. [Figure 7] 1 is a flow chart illustrating steps for manufacturing an aerosol generating device in accordance with one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] FIG. 1 is a schematic cross-sectional view of an aerosol generating device 100 in accordance with an embodiment of the present invention. The aerosol generating device 100 includes a vacuum chamber 102 defined between an inner wall 104 and an outer wall 106. A heating chamber 108 is provided radially inward of the inner wall 104 for receiving an aerosol-forming substrate (not shown). A heater 110 is provided on an outer surface of the inner wall 104. The heater 110 is a track heater that may be printed or coated on the outer surface of the inner wall 104. The heater 110 can heat the inner wall 104 and transfer heat into the heating chamber 108 by thermal conduction to heat the aerosol-forming substrate received therein. The outer wall 106 is preferably housed within an outer shell (not shown) of the device, which may be made of plastic, metal, or any other suitable material.

[0023] The inner wall 104 is substantially cup-shaped or U-shaped. The inner wall 104 is nested within a similarly shaped outer wall 106. The inner wall 104 and the outer wall 106 are joined together at their upper ends and enclose a vacuum between them.

[0024] The vacuum chamber 102 is configured to provide thermal insulation between the heat generated by the heater 110 and the outer wall 106. More specifically, the vacuum chamber 102 is configured to provide thermal insulation between the heat generated by the heater 110 and a user of the device. Typically, the device is held by a user gripping an outer shell (not shown) of the device that surrounds the outer wall 106. The vacuum chamber 102 is preferably an evacuated chamber. Alternatively, the vacuum chamber 102 may include multiple individual evacuated units disposed within the vacuum chamber that provide the desired thermal insulation. The vacuum chamber 102 may be formed by welding or otherwise connecting the inner wall 104 and the outer wall 106 together at their upper ends using known techniques.

[0025] The vacuum chamber 102 is an insulating chamber that can provide insulation between the heat generated by the heater 110 and the exterior wall 106. In this embodiment, the insulating chamber is described as a vacuum chamber, but other materials can alternatively be provided within the chamber to provide insulation. Examples of alternative materials that can be used include powdered or fibrous materials such as aerogel, or air.

[0026] The inner wall 104 defines an inner surface of the vacuum chamber 102 and is configured to define a heating chamber 108. In this embodiment, the inner wall 104 is substantially cylindrical and has a circular cross-sectional shape to match the cross-sectional shape of the aerosol-forming substrate. The inner wall 104 also has a side wall and a bottom wall. The inner wall 104 is shaped such that the aerosol-forming substrate can be closely received within the heating chamber 108. The inner wall 104 is preferably made of a material that efficiently conducts heat, such as a metal.

[0027] The outer wall 106 is configured to define an exterior of the vacuum chamber 102. The outer wall 106 is also substantially cylindrical and has a side wall 106a and a bottom wall 106b. The outer wall 106 is made of a conductive material, such as a metal.

[0028] The heating chamber 108 is configured to receive the aerosol-forming substrate. The heating chamber 108 may include a groove portion or other means suitable for holding the aerosol-forming substrate. A mouthpiece portion (not shown) may be provided from which a user may inhale the aerosol generated from the aerosol-forming substrate. Alternatively, the aerosol-forming substrate itself may be the mouthpiece through which the aerosol may be inhaled.

[0029] The heater 110 is configured to heat an aerosol-forming substrate received within the heating chamber 108. The aerosol-forming substrate may be comprised of a tobacco substrate, which may include shredded tobacco, and may be a solid or semi-solid that can be heated without being burned. In alternative scenarios, the aerosol-forming substrate may include other types of substrates, such as a vaporizable liquid substrate held in a reservoir.

[0030] The first electrical connector 114 and the second electrical connector 116 are configured to form an electrical connection between the heater 110 and the first region 112 and the second region 113 of the outer wall, respectively. In this example, the first electrical connector 114 and the second electrical connector 116 are spring loaded. In this manner, the respective regions of the heater 110 and the outer wall 106 can be biased toward one another. In the exemplary embodiment of FIG. 1, the first electrical connector 114 is biased in a counterclockwise direction from its connection with the heater 110, which tends to push the electrical connector 114 into contact with the second region 113 of the outer wall 106. The second electrical connector 114 is also biased in a counterclockwise direction from its connection with the heater 110, which pushes it toward the first region 112 of the outer wall 106.

[0031] The first electrical connector 114 and the second electrical connector 116 facilitate the transfer of electrical power from the exterior wall 106 to the heater 110, which is configured to be connected to a power source.

[0032] The insulator 118 is configured to electrically insulate the first region 112 and the second region 113 of the outer wall from each other. The insulator 118 is provided on the outer wall 106. The insulator 118 comprises an insulating material such as rubber or plastic. The insulator 118 can be a gasket or an insulating strip provided on the outer wall 106. In the embodiment of Figures 1 and 3, the insulator 118 is provided on the bottom wall 106b of the outer wall 106. In the embodiment of Figure 2, the insulator 118 is provided circumferentially around the side wall 106a of the outer wall. In further alternative embodiments of the present invention, the insulator 118 can be provided on the side wall 106a and the bottom wall 106b or a combination of the two.

[0033] In a preferred embodiment, the heater 110 also includes an electrical terminal 120. A first electrical connector 114 and a second electrical connector 116 are configured to form an electrical connection between the electrical terminal 120 of the heater 110 and the first region 112 and second region 113 of the outer wall, respectively.

[0034] In the embodiment of Fig. 1, a first electrical connector 114 forms an electrical connection between a first portion of the heater 110 and a first region 112 of the outer wall, the first region 112 being located on a side wall 106a of the outer wall. A second electrical connector 116 forms an electrical connection between a second portion of the heater 110 and a second region 113 of the outer wall, the second region 113 being located on a bottom wall 106b of the outer wall. The first electrical connector 114 and the second electrical connector 116 are biased in a counterclockwise direction as viewed from the connection with the heater 110. An insulator 118 is provided circumferentially on the bottom wall 106b.

[0035] In the alternative embodiment of Fig. 2, a first electrical connector 114 forms an electrical connection between a first portion of the heater 110 and a first region 112 of the outer wall, the first region 112 being located on the side wall 106a of the outer wall. A second electrical connector 116 forms an electrical connection between a second portion of the heater 110 and a second region 113 of the outer wall, the second region 113 being located on the side wall 106a of the outer wall. The first electrical connector 114 and the second electrical connector 116 are biased in a counterclockwise direction as viewed from the connection with the heater 110. An insulator 118 is provided circumferentially on the side wall 106a.

[0036] In the embodiment of FIG. 3, the first electrical connector 114 forms an electrical connection between a first portion of the heater 110 and a first region 112 of the outer wall, the first region 112 being located on the bottom wall 106b of the outer wall. The second electrical connector 116 forms an electrical connection between a second portion of the heater 110 and a second region 113 of the outer wall, the second region 113 being located on the bottom wall 106b of the outer wall. The second region 113 in this embodiment is a partial region of the bottom wall 106b of the outer wall. The first electrical connector 114 is biased in a clockwise direction as viewed from the connection with the heater 110. The second electrical connector 116 is biased in a clockwise direction as viewed from the connection with the heater 110. An insulator 118 is provided on a partial region of the bottom wall 106b.

[0037] The first region 112 and the second region 113 may be connected to a power source to induce a flow of electrical current between the first and second portions of the electrically resistive heater 110, respectively, thereby generating heat.

[0038] In the embodiment of Figures 4a, 4b and 4c, the insulator 118 is provided on the bottom wall 106b of the outer wall 106. In this example, the insulator 118 is substantially ring-shaped and provided circumferentially around the first region 112 of the outer wall located on the bottom wall 106b. The insulator 118 includes a protrusion 122 that is provided outwardly from the outer wall 106, outside the vacuum chamber 102. The protrusion 122 is oriented substantially parallel to the longitudinal axis of the device, which in this example is defined as being parallel to the side wall 106a.

[0039] The protrusions 122 increase the shortest path 126, or creepage distance, that an electron must take along the surface of the insulator 118 from the first region 112 to the second region 113 of the outer wall (or vice versa) to create a short circuit. Because the outer surface of the insulator 118 may have or potentially have material present that may support even a small current flow, it is believed that there is a greater chance of a short circuit occurring outside of the vacuum chamber 102. The longer the shortest path 126 across the surface of the insulator 118 between the first and second regions, the lower the risk of a short circuit.

[0040] A person skilled in the art will appreciate that the protrusion 122 may have any shape, which may include multiple vertices, and the shortest path 126 across the surface of the insulator 118 may be, for example, a circular arc. In the embodiment of FIG. 4a, the protrusion 122 has a trapezoidal cross section. The shortest path 126 is across two vertices of the protrusion 122 of the insulator 118. In the embodiment of FIG. 4b, the protrusion 122 has a square cross section. The shortest path 126 is across two vertices of the protrusion 122 of the insulator 118. In the embodiment of FIG. 4c, the protrusion 122 has a triangular cross section. The shortest path 126 is across a vertex of the protrusion 122 of the insulator 118.

[0041] In the embodiment of Fig. 5, the insulator 118 is provided on the bottom wall 106b of the outer wall. In this example, the insulator 118 is substantially ring-shaped and provided circumferentially around the first region 112 of the outer wall located on the bottom wall 106b. The insulator 118 includes a protrusion 122 that is provided outwardly from the outer wall 106, outside the vacuum chamber 102, substantially parallel to the longitudinal axis of the apparatus.

[0042] In this example, the first region 112 of the outer wall is recessed into the vacuum chamber 102 relative to the second region 113 of the outer wall, causing a majority of the protrusion 122 of the insulator 118 to protrude outwardly from the outer wall 106. Because the recession of the first region 112 of the outer wall increases the surface area of ​​the insulator 118, the shortest path 126 across the insulator 118 increases both inside and outside the vacuum chamber 102.

[0043] 6, the insulator 118 is substantially ring-shaped and disposed circumferentially around the bottom wall 106b between the side wall 106a and the bottom wall 106b. The insulator 118 includes a recess on its inner surface that surrounds a portion of the bottom wall 106b and holds the bottom wall 106b therein. By surrounding a portion of the bottom wall 106b, the insulator 118 increases its surface area, so that the shortest path 126 increases inside and outside the vacuum chamber 102.

[0044] In this example, the sidewall 106a further includes a groove or groove portion 124 configured to clamp and hold the bottom wall 106b to maintain the vacuum within the vacuum chamber 102. In this embodiment, the first region 112 is located on the sidewall 106a and the second region 113 is located on the bottom wall 106b. It will be apparent to one skilled in the art that the arrangement illustrated in this embodiment of the invention may also be implemented with the sidewall 106a.

[0045] 7 is a flow chart showing steps for manufacturing an aerosol generating device 100 in accordance with an embodiment of the present invention. In step 202, a heater 110 is provided on the inner wall 104. More specifically, the heater 110 is provided on the outer surface of the inner wall 104. In a preferred embodiment, the heater 110 is a track heater that may be printed on the outer surface of the inner wall. In an alternative embodiment, the heater 110 may be secured to the inner wall 104 by means such as an adhesive. Alternatively, the heater 110 may be wrapped around the periphery of the inner wall 104.

[0046] In step 204, a heating chamber 108 is formed inside the inner wall 104. In step 206, the first region 112 and the second region 113 of the outer wall are insulated from each other using an insulator 118. In an embodiment of the invention, the insulator 118 is a gasket that includes an insulating material.

[0047] In step 208, a first electrical connection is made between the heater 110 and the first region 112 of the exterior wall.

[0048] In step 210, a second electrical connection is made between the heater 110 and a second region 113 of the outer wall.

[0049] The first and second electrical connections are made by wires connecting the heater 110 to the first and second regions 112 and 113 of the outer wall, respectively. More specifically, the first and second electrical connections are made by spring-loaded electrical connectors.

[0050] In step 212, a vacuum chamber 102 is formed between the inner wall 104 and the outer wall 106. The vacuum chamber 102 is an evacuated chamber. Alternatively, the vacuum chamber 102 may include multiple individual evacuated units disposed within the vacuum chamber 102 that provide the desired insulation. The vacuum chamber 102 may be formed by welding or otherwise connecting the inner wall 104 and the outer wall 106 together using known techniques.

Claims

1. An aerosol generating device, comprising a chamber defined between an inner wall and an outer wall, wherein the outer wall is made of a conductive material, and a heating chamber capable of receiving an aerosol forming substrate is defined radially inside the inner wall; a heater on the outer surface of the inner wall; and the heater is electrically connected to a first region of the outer wall and a second region of the outer wall, and the first region and the second region are electrically insulated from each other, the aerosol generating device.

2. The aerosol generating device according to claim 1, wherein the chamber is a vacuum chamber.

3. The aerosol generating device according to claim 1 or 2, wherein the heater and the first region of the outer wall are biased towards each other.

4. The aerosol generating device according to claim 1 or 2, wherein the heater and the second region of the outer wall are biased towards each other.

5. The aerosol generating device according to claim 1 or 2, wherein the outer wall includes a side wall and a bottom wall.

6. The aerosol generating device according to claim 5, wherein the first region of the outer wall is on the side wall, and the second region of the outer wall is on the bottom wall.

7. The aerosol generating device according to claim 5, wherein the first region of the outer wall is on the side wall, and the second region of the outer wall is on the side wall.

8. The aerosol generating device according to claim 5, wherein the first region of the outer wall is on the bottom wall, and the second region of the outer wall is on the bottom wall.

9. The aerosol generating device according to claim 1 or 2, wherein the first region and the second region are each electrically connected to a power source.

10. The aerosol generator according to claim 1 or 2, wherein the non-linear path is provided along the surface of an insulator outside the chamber between the first region of the outer wall and the second region of the outer wall.

11. The aerosol generator according to claim 10, wherein the insulator protrudes from the outer wall outside the chamber.

12. The aerosol generator according to claim 1 or 2, wherein the first region of the outer wall is clamped by the second region of the outer wall.

13. The aerosol generator according to claim 12, wherein the second region of the outer wall includes a groove that can receive the first region of the outer wall so that the first region of the outer wall is clamped.

14. The aerosol generator according to claim 1 or 2, wherein the first region of the outer wall is recessed from the second region of the outer wall.

15. A method of manufacturing an aerosol generator, comprising: forming a chamber between an inner wall and an outer wall made of a conductive material, and forming a heating chamber that can receive an aerosol-forming substrate, which is defined radially inward of the inner wall; providing a heater on the outer surface of the inner wall; creating electrical connections between the heater and the first region of the outer wall and between the heater and the second region of the outer wall; electrically insulating the first region and the second region from each other; and a method including the above.

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