HEATING COMPONENT IN AEROSOL GENERATING DEVICES

Abstract

An electronic aerosol-generating device includes a housing extending between first and second ends along a longitudinal axis. The second end of the housing defines a cavity for receiving a consumable containing an aerosol generating substrate. The device further includes a heating component comprising a heating element extending along the longitudinal axis within the cavity and configured to penetrate into the aerosol generating substrate when the consumable is inserted into the cavity. The heating element comprises a material having a Curie temperature of less than 500° C. The device also includes an inductor comprising an inductor coil positioned to transfer magnetic energy to the heating element. The inductor is configured to induce eddy currents and/or hysteresis losses in the heating element. The device further includes a power supply operably connected to the inductor and control electronics operably connected to the power supply and configured to control heating of the heating element.

Claims

1-16. (canceled)

17. An electronic device for receiving a consumable comprising an aerosol generating substrate, the electronic device comprising: a housing extending between a first end and a second end along a longitudinal axis, wherein the housing comprises: a cavity configured to receive the consumable; a recess configured to releasably receive a heating component comprising a heating element; an inductor comprising an inductor coil that is configured to generate eddy currents and/or hysteresis losses in the heating element when the heating component is received in the housing; a power supply operably connected to the inductor; and control electronics connected to the power supply.

18. The electronic device of claim 17, further comprising the heating component comprising a heating element received in the housing.

19. The electronic device of claim 18 wherein the power supply is coupled to the heating element and is configured to control heating of the heating element.

20. The electronic device according to claim 18, wherein the heating element comprises a material having a Curie temperature of less than 500° C.

21. The electronic device according to claim 20, wherein the heating element further comprises a protective layer covering the outer surface of the material having the Curie temperature of less than 500° C.

22. The electronic device according to claim 20, wherein the control electronics is configured to detect when the heating element reaches the Curie temperature of the material having a Curie temperature of less than 500° C.

23. The electronic device according to claim 22, wherein the control electronics is configured to switch off, or limit the power supply to the inductor when the temperature of the heating element having a Curie temperature of less than 500° C. reaches a threshold temperature, and to switch on, or increase, the power supply to the inductor when the temperature of the heating element having a Curie temperature of less than 500° C. is below a threshold temperature.

24. The electronic device according to claim 20, wherein the material having the Curie temperature of less than 500° C. is selected from the group consisting of nickel alloy and nickel.

25. The electronic device according to claim 20, wherein the heating element further comprises a second susceptor material positioned in thermal contact with the material having a Curie temperature of less than 500° C.

26. The electronic device according to claim 25, wherein the second susceptor material is selected from the group consisting of aluminum, iron, iron alloy, and stainless steel.

27. A device according to claim 25, wherein the material having the Curie temperature of less than 500° C. and the second susceptor material are co-laminated and comprise an elongate strip having a width of between 3 mm and 6 mm and a thickness of between 10 micrometers and 200 micrometers, where the second susceptor material has a greater thickness than the material having the Curie temperature of less than 500° C.

28. A device according to claim 25, wherein the heating element comprises an elongate strip having a width of between 3 mm and 6 mm and a thickness of between 10 micrometers and 200 micrometers, wherein the heating element comprises a core of the material having the Curie temperature of less than 500° C. being at least in part encapsulated by the second susceptor material.

29. A device according to claim 20, wherein the material is adapted to control the temperature of the heating element without use of a temperature sensor.

30. A device according to claim 18 wherein the heating element has a front end configured to penetrate into the consumable comprising an aerosol generating substrate.

31. A device according to claim 30 wherein the front end of the heating element comprises a tapered edge.

32. A device according to claim 17 wherein the aerosol generating substrate comprises solid, liquid or gel.

33. A device according to claim 32 wherein the aerosol generating substrate comprises nicotine.

34. A device according to claim 18 wherein the heating component comprises a guard transverse to the heating element.

35. A device according to claim 34 wherein the guard is between the heating element of the heating component and the housing.

36. A device according to claim 35 further comprising a thermal insulator positioned between the guard of the heating component and the housing.

Description

[0088] Referring now to the drawings, in which some aspects of the present invention are illustrated. It will be understood that other aspects not depicted in the drawings fall within the scope and spirit of the present invention. The drawings are schematic drawings and are not necessarily to scale. Like numbers used in the figures refer to like components, steps and the like. However, it will be understood that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labelled with the same number. In addition, the use of different numbers to refer to components in different figures is not intended to indicate that the different numbered components cannot be the same or similar to other numbered components.

[0089] FIG. 1A is a schematic plan view of an embodiment of a heating blade for use in an aerosol generating device according to an embodiment of the invention;

[0090] FIG. 1B is a schematic side view of the heating blade of FIG. 1A;

[0091] FIG. 2A is a schematic plan view of another embodiment of a heating blade for use in an aerosol generating device according to an embodiment of the invention;

[0092] FIG. 2B is a schematic side view of the heating blade of FIG. 2A;

[0093] FIG. 3 is a schematic cross section of an embodiment of an electronic aerosol generating device;

[0094] FIG. 4 is a schematic cross section of an embodiment of a consumable including an aerosol generating substrate;

[0095] FIG. 5 is a schematic cross section of the consumable of FIG. 4 received within a cavity of the electronic device of FIG. 3;

[0096] FIG. 6 is a schematic cross section of the electronic device of FIG. 3 with a first portion of the device removed from a second portion of the device;

[0097] FIG. 7A is a schematic cross section of an embodiment of a first and second portion of an embodiment of an electronic aerosol generating device separated from one another; and

[0098] FIG. 7B is a schematic cross section of the first and second portions of the electronic device of FIG. 7A attached to one another.

[0099] Inductive heating is a known phenomenon described by Faraday's law of induction and Ohm's law. More specifically, Faraday's law of induction states that if the magnetic induction in a conductor is changing, a changing electric field is produced in the conductor. Since this electric field is produced in a conductor, a current, known as an eddy current, will flow in the conductor according to Ohm's law. The eddy current will generate heat proportional to the current density and the conductor resistivity. A conductor which is capable of being inductively heated is known as a susceptor material. The present invention employs an inductive heating device equipped with an inductive heating source, such as, e.g., an induction coil, which is capable of generating an alternating electromagnetic field from an AC source such as an LC circuit. Heat generating eddy currents are produced in the susceptor material which is in thermal proximity to an aerosol-forming substrate which is capable of releasing volatile compounds that can form an aerosol upon heating. The primary heat transfer mechanisms from the susceptor material to the solid material are conduction, radiation and possibly convection.

[0100] FIGS. 1A and 1B illustrate a specific example of a unitary multi-material heating blade adapted to be attached to an aerosol generating device and inserted into a consumable according to an embodiment of the invention. The depicted heating blade 10 is in the form of an elongate strip that may have any suitable dimensions, such as a length of 12 mm and a width of 4 mm. The heating blade is formed from a second material 20 that is intimately coupled to a first material 30. The second material 20 is in the form of a strip of suitable material, such as grade 430 stainless steel, having suitable dimensions, such as 12 mm by 4 mm by 35 micrometres. The first material 30 may be a patch of nickel of dimensions 3 mm by 2 mm by 10 micrometres. The patch of nickel has been electroplated onto the strip of stainless steel or deposited in any other suitable manner. Grade 430 stainless steel is a ferromagnetic material having a Curie temperature in excess of about 500° C. Nickel is a ferromagnetic material having a Curie temperature of about 354° C. (the exact Curie temperature of nickel will depend on the purity).

[0101] In further embodiments the material forming the first and second materials may be varied. In further embodiments there may be more than one patch of the first material located in intimate contact with the second material.

[0102] FIG. 2A illustrates the first material 30 completely surrounding and enclosing the second material 20. FIG. 2B illustrates a second specific example of a unitary multi-material heating blade. The heating blade 10 is in the form of an elongate strip having suitable dimensions, such as a length of 12 mm and a width of 4 mm. The heating blade 10 is formed from a second material 20 that is intimately coupled to a first material 30. The second material 20 is in the form of a strip of, for example, grade 430 stainless steel having suitable dimensions, such as 12 mm by 4 mm by 25 micrometres. The first material 30 is in the form of a strip of suitable material, such as nickel, having dimensions of, for example, 12 mm by 4 mm by 10 micrometres. The heating blade 10 is formed by cladding the strip of nickel 6 to the strip of stainless steel 5 or other suitable deposition process. The total thickness of the heating blade 10 may be, for example, 35 micrometres. The heating blade 10 of FIG. 2B may be termed a bi-layer or multilayer heating blade.

[0103] An electronic device 100 including a housing 110 is shown in FIG. 3. The housing 110 extends between a first end 111 and a second end 112 along a longitudinal axis 101. The housing 110 has a cavity 160 proximate the second end 112 of the housing 110 for receiving the consumable 50.

[0104] A heating component 140 is operably attached to the housing 110 within the cavity 160. The heating component 140 includes a heating blade 142 extending along the longitudinal axis 101 within the cavity 160 and configured to be inserted into the consumable 50 (e.g., the aerosol generating substrate 52) when the consumable 50 is inserted into the cavity 160. The heating component 140 may be configured to be received by the housing 110 such that the heating component 140 may be removably attachable to the housing 110. The heating component 140 also may include a guard 144 that may be transverse (e.g., perpendicular) to the heating blade 142. In other words, the heating blade 142 may extend normal to a surface of the guard 144. For example, the heating blade 142 may extend from a first surface 145 of the guard 144.

[0105] The heating blade 142 may extend between a base end 151 proximate the guard 144 and a front end 152 away from the guard 144. The front end 152 of the heating blade 142 may have a tapered edge (e.g., as shown in FIG. 2). The tapered edge of the front end 152 of the heating blade 142 may be configured to penetrate into the consumable 50 (e.g., the aerosol generating substrate 52).

[0106] The electronic device 100 may include comprises a power supply 190 and control electronics 192 that allow the inductor 120 to be actuated. Such actuation may be manually operated or may occur automatically in response to a user drawing on a consumable 50 inserted into the cavity 160 of the electronic device 100. The power supply 190 may supply a DC current. The electronics include a DC/AC inverter for supplying the inductor with a high frequency AC current.

[0107] The electronic device 100 may also include an inductor 120 operably coupled to the power supply 190 and the control electronics 192 to produce heat in the heating component 140. The inductor 120 may include an inductor coil 122 positioned around the heating blade 142. For example, as shown in FIG. 3, the induction coil 106 may be positioned around the cavity 160. The inductor 120 may be configured to excite the heating blade 142. In use, the user inserts the consumable 50 into the cavity 160 of the housing 110 such that the aerosol generating substrate 52 of the consumable 50 is located adjacent the inductor 120.

[0108] When the device is actuated, a high-frequency alternating current is passed through coils 122 of wire that form part of the inductor 120. This causes the inductor 120 to generate a fluctuating magnetic field within a distal portion of the cavity 160 of the housing 110. The magnetic field preferably fluctuates with a frequency of between 1 and 30 MHz, preferably between 2 and 10 MHz, for example between 5 and 7 MHz. The fluctuating field generates eddy currents and/or hysteresis losses within the heating blade 142, which is heated as a result. The heated blade heats the aerosol generating substrate 52 of the consumable 50 to a sufficient temperature to form an aerosol. The aerosol is drawn downstream through the consumable 50 and inhaled by the user.

[0109] As the heating blade 142 is heated during operation its apparent resistance (Ra) increases. This increase in resistance can be remotely detected by monitoring the DC current drawn from the DC power supply 190, which at constant voltage decreases as the temperature of the heating blade 142 increases. The high frequency alternating magnetic field provided by the inductor 120 induces eddy currents in close proximity to the heating blade surface, an effect that is known as the skin effect. The resistance in the heating blade depends in part on the electrical resistivities of the first and second materials and in part on the depth of the skin layer in each material available for induced eddy currents. As the first material (e.g., Nickel) reaches its Curie temperature it loses its magnetic properties. This causes an increase in the skin layer available for eddy currents in the first material, which causes a decrease in the apparent resistance of the heating blade. The result is a temporary increase in the detected DC current when the first material reaches its Curie point.

[0110] By remote detection of the change in resistance in the heating blade 142, the moment at which the heating blade 142 reaches the first Curie temperature can be determined. At this point the heating blade 142 is at a known temperature (354° C. in the case of a Nickel susceptor). At this point the electronics in the device operate to vary the power supplied to the inductor and thereby reduce or stop the heating of the heating blade 142. The temperature of the heating blade 142 then decreases to below the Curie temperature of the first material. The power supply 190 may be increased again, or resumed, either after a period of time or after it has been detected that the first material has cooled below its Curie temperature. By use of such a feedback loop the temperature of the heating blade 142 may be maintain to be approximately that of the first Curie temperature.

[0111] FIG. 4 illustrates a consumable 50 (e.g., an aerosol-generating article) according to a preferred embodiment. The consumable 50 comprises four elements arranged in coaxial alignment: an aerosol generating substrate 52, a support element 53, an aerosol-cooling element 54, and a mouthpiece 55. Each of these four elements is a substantially cylindrical element, each having substantially the same diameter. These four elements are arranged sequentially and are circumscribed by an outer wrapper 56 to form a cylindrical rod. The heating blade 142 is adapted to penetrate into the aerosol generating substrate 52 of the consumable 50 (e.g., a distal end 58). The aerosol generating substrate 52 has a length (12 mm) that is approximately the same as the length of the heating blade 142.

[0112] The consumable 50 has a proximal or mouth end 57, which a user inserts into his or her mouth during use, and a distal end 58 located at the opposite end of the consumable 50 to the mouth end 57. Once assembled, the total length of the consumable 50 is about 45 mm and the diameter is about 7.2 mm.

[0113] In use air is drawn through the consumable 50 by a user from the distal end 58 to the mouth end 57. The distal end 58 of the consumable 50 may also be described as the upstream end of the consumable 50 and the mouth end 57 of the consumable 50 may also be described as the downstream end of the consumable 50. Elements of the consumable 50 located between the mouth end 57 and the distal end 58 can be described as being upstream of the mouth end 57 or, alternatively, downstream of the distal end 58.

[0114] The aerosol generating substrate 52 is located at the extreme distal or upstream end 58 of the consumable 50. In the embodiment illustrated in FIG. 4, the aerosol generating substrate 52 includes a gathered sheet of crimped homogenised tobacco material circumscribed by a wrapper. The crimped sheet of homogenised tobacco material comprises glycerine as an aerosol-former.

[0115] The support element 53 is located immediately downstream of the aerosol generating substrate 52 and abuts the aerosol generating substrate 52. In the embodiment shown in FIG. 4, the support element is a hollow cellulose acetate tube. The support element 53 locates the aerosol generating substrate 52 at the extreme distal end 58 of the consumable 50. The support element 53 also acts as a spacer to space the aerosol-cooling element 54 of the consumable 50 from the aerosol generating substrate 52.

[0116] The aerosol-cooling element 54 is located immediately downstream of the support element 53 and abuts the support element 53. In use, volatile substances released from the aerosol generating substrate 52 pass along the aerosol-cooling element 54 towards the mouth end 57 of the consumable 50. The volatile substances may cool within the aerosol-cooling element 54 to form an aerosol that is inhaled by the user. In the embodiment illustrated in FIG. 4, the aerosol cooling element 54 includes a crimped and gathered sheet of polylactic acid circumscribed by a wrapper 59. The crimped and gathered sheet of polylactic acid defines a plurality of longitudinal channels that extend along the length of the aerosol-cooling element 54.

[0117] The mouthpiece 55 is located immediately downstream of the aerosol-cooling element 54 and abuts the aerosol-cooling element 54. In the embodiment illustrated in FIG. 4, the mouthpiece 55 comprises a conventional cellulose acetate tow filter of low filtration efficiency.

[0118] To assemble the consumable 50, the four cylindrical elements described above are aligned and tightly wrapped within the outer wrapper 56. In the embodiment illustrated in FIG. 4, the outer wrapper is a conventional cigarette paper. The consumable 50 illustrated in FIG. 4 is designed to engage with an electrically-operated aerosol generating device comprising an induction coil, or inductor, in order to be consumed by a user.

[0119] FIG. 5 illustrates a consumable 50 received by the cavity 160 of the housing 110 and in engagement with the heating blade 142 of the electronic device 100.

[0120] FIG. 6 illustrates the electronic device 100 including a first portion 102 and a second portion 104 separated from one another. The first and second portions 102, 104 are removably attachable to each other. As shown in FIG. 6, the first portion 102 includes the inductor 120 and a portion of the housing 110 that has the cavity 160 and the second portion 104 includes the heating component 140 (e.g., the heating blade 142, which in other embodiments may itself be detachable—for example as one unit together with the guard 144 that may act as a holder for the heating blade 142). Further, the second portion 104 includes the power supply 190 and the control electronics 192. The inductor 120 is operably coupled to the control electronics 192 and the power supply 190 when the first portion 102 is attached to the second portion 104 (e.g., as shown in FIG. 3). Positioning the inductor coil 122 within the first portion 102 may require the power supply 190 and control electronics 192 to be operably connected to the inductor coil 122. As a result, an electrical connection may extend from the control electronics 192 and into the first portion 102 through an interface between the first and second portions 102, 104 when the first and second portions 102, 104 are attached.

[0121] FIG. 7A illustrates another arrangement of first and second portions 202, 204 of an electronic device 200 separated from one another. For example, the first portion 202 may include an inductor 220, a portion of the housing 210 that has the cavity 260, a power supply 290, and control electronics 292. The second portion 204 may include a heating component 240 (e.g., a heating blade 242). When the second portion 204 is attached to the first portion 202 (e.g., as shown in FIG. 7B), the heating blade 242 is positioned such that the inductor 220 excites the heating blade 242. In the embodiment shown in FIGS. 7A and 7B, the first and second portions 202, 204 are only physically attached to one another and do not require an electrical connection. For example, the power supply 290, the control electronics 292, and the inductor 220 are all included within the first portion 202 and, therefore, are electrically coupled to one another regardless of whether or not the first portion 202 is attached to the second portion 204. As a result, the user is less restricted in attaching the first portion 202 to the second portion 204 because no electrical connection between the first and second portions 202, 204 is required.

[0122] The various features described through FIGS. 1-7B may be used in combination with any other feature described in FIGS. 1-7B, so long as they are not inconsistent with one another.

[0123] Thus, methods, systems, devices, compounds and compositions for HEATING COMPONENT IN AEROSOL GENERATING DEVICES are described. Various modifications and variations of the invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are apparent to those skilled in electronic device manufacturing or related fields are intended to be within the scope of the following claims.