Aerosol-generating device with reduced spacing inductor coils

Abstract

The present invention provides an aerosol-generating device (12) comprising: a housing (16) defining a chamber (18) for receiving at least a portion of an aerosol-generating article (14); and an inductor coil (26), the inductor coil being arranged within the chamber (18). The aerosol-generating device (12) further comprises a power source (32) and a controller (30) connected to the inductor coil (26) and configured to provide an alternating current to the inductor coil (26) such that, in use, the inductor coil (26) is electrically connected to the power source (32). The inductor coil (26) generates an alternating magnetic field to inductively heat a susceptor element (24) and thereby heat at least a portion of an aerosol-generating article (14) received within the inductor coil (26).

Description

[0001] This application is a divisional application of the invention patent application entitled "Aerosol generating device with inductor coil with reduced spacing", with an international application date of August 9, 2018, an international application number of PCT / EP2018 / 071705, and a national application number of 201880047369.4. Technical Field

[0002] The present invention relates to an aerosol generating device having an inductor coil arranged to contact an aerosol generating article. The present invention also relates to an aerosol generating system comprising an aerosol generating device and an aerosol generating article for use with the aerosol generating device. Background Art

[0003] Many electrically powered aerosol generating systems have been proposed in the art, in which an aerosol generating device with an electric heater is used to heat an aerosol-forming substrate, such as a tobacco filter segment. One purpose of such an aerosol generating system is to reduce known types of harmful smoke components produced by the combustion and pyrolytic degradation of tobacco in conventional cigarettes. Typically, the aerosol generating substrate is provided as part of an aerosol generating article, which is inserted into a chamber or cavity of the aerosol generating device. In some known systems, in order to heat the aerosol-forming substrate to a temperature capable of releasing volatile components that can form an aerosol, a resistive heating element (such as a heating blade) is inserted into or around the aerosol-forming substrate when the article is received in the aerosol generating device. In other aerosol generating systems, an induction heater is used instead of a resistive heating element. The induction heater typically includes: an inductor, which forms part of the aerosol generating device; and a conductive susceptor element, which is within the aerosol generating device and is arranged so that it is thermally close to the aerosol-forming substrate. During use, the inductor generates an alternating magnetic field to generate eddy currents and hysteresis losses in the susceptor element, thereby heating the susceptor element and thereby heating the aerosol-forming substrate.

[0004] Induction heating systems rely on inductive energy transfer from an inductor to a susceptor element.It is desirable to provide an aerosol generating device which improves the energy transfer from the inductor to the susceptor element. Summary of the invention

[0005] According to a first aspect of the invention, there is provided an aerosol generating device comprising: a housing defining a chamber for receiving at least a portion of an aerosol generating article; and an inductor coil disposed at least partially within the chamber. The aerosol generating device further comprises a power supply and a controller connected to the inductor coil and configured to provide an alternating current to the inductor coil such that, in use, the inductor coil generates an alternating magnetic field to inductively heat a susceptor element and thereby heat at least a portion of the aerosol generating article received within the chamber.

[0006] As used herein, the term "longitudinal" is used to describe the direction along the major axis of an aerosol-generating device or an aerosol-generating article, and the term "transverse" is used to describe the direction perpendicular to the longitudinal direction. When referring to a chamber or an inductor coil, the term "longitudinal" refers to the direction in which the aerosol-generating article is inserted into the chamber or the inductor coil, and the term "transverse" refers to the direction perpendicular to the direction in which the aerosol-generating article is inserted into the chamber or the inductor coil.

[0007] As used herein, the term "width" refers to the major dimension of an aerosol-generating device or a component of an aerosol-generating article at a specific position along its length in the transverse direction. The term "thickness" refers to the dimension of an aerosol-generating device or a component of an aerosol-generating article along the transverse direction perpendicular to the width.

[0008] As used herein, the term "aerosol-forming substrate" relates to a substrate capable of releasing volatile compounds, which can form an aerosol. Such volatile compounds can be released by heating the aerosol-forming substrate. The aerosol-forming substrate is part of an aerosol-generating article.

[0009] As used herein, the term "aerosol-generating article" refers to an article comprising an aerosol-forming substrate capable of releasing volatile compounds that can form an aerosol. For example, an aerosol-generating article can be an article that generates an aerosol that can be directly inhaled by a user drawing or sucking on a mouthpiece at the proximal or user end of the system. The aerosol-generating article can be disposable. Articles that include an aerosol-forming substrate containing tobacco are referred to as tobacco rods.

[0010] As used herein, the term "aerosol-generating device" refers to a device that interacts with an aerosol-generating article to generate an aerosol.

[0011] As used herein, the term "aerosol generating system" refers to the combination of an aerosol generating article as further described and illustrated herein and an aerosol generating device as further described and illustrated herein. In an aerosol generating system, the aerosol generating article and the aerosol generating device cooperate to generate a respirable aerosol.

[0012] As used herein, the term "elongated" refers to a component having a length greater than both its width and thickness (eg, twice its width and thickness).

[0013] As used herein, "susceptor element" refers to an electrically conductive element that heats when subjected to a changing magnetic field. This may be the result of eddy currents induced in the susceptor element, hysteresis losses, or both eddy currents and hysteresis losses. In use, the susceptor element is located in thermal contact or close thermal proximity to an aerosol-forming substrate of an aerosol-generating article received in an inductor coil of an aerosol-generating device. In this way, the aerosol-forming substrate is heated by the susceptor element during use, so that an aerosol is formed. The susceptor element may form part of an aerosol-generating device or part of an aerosol-generating article.

[0014] Advantageously, due to the power losses associated with resistive heaters, particularly losses due to contact resistance at the connection between the resistive heater and the power source, using induction heating rather than resistive heating may provide improved energy conversion.

[0015] Advantageously, arranging the inductor coil at least partially within the chamber can reduce or minimize the distance between the inductor coil and the susceptor element. Advantageously, arranging the inductor coil at least partially within the chamber can eliminate any intermediate material between the inductor coil and the aerosol-generating article. Advantageously, one or both of these features can maximize the inductive energy transfer from the inductor coil to the susceptor element. This can be particularly important in embodiments where the susceptor element is positioned within the interior of the aerosol-generating article during use.

[0016] The aerosol-generating article may comprise a susceptor element at least partially arranged within an inductor coil. Advantageously, providing both the inductor coil and the susceptor element as part of the aerosol-generating device allows for the construction of a simple, inexpensive and durable aerosol-generating article. Aerosol-generating articles are typically disposable and are produced in greater quantities than the aerosol-generating device with which they are used. Therefore, reducing the cost of the article may result in significant cost savings for manufacturers and consumers, even if a more expensive device is required.

[0017] Preferably, the susceptor element is an elongated susceptor element. Preferably, the elongated susceptor element is arranged to be inserted into the aerosol-generating article when the aerosol-generating article is inserted into the inductor coil. Advantageously, an elongated susceptor element arranged to be inserted into the aerosol-generating article may optimize heat transfer from the susceptor element to the aerosol-forming substrate of the aerosol-generating article.

[0018] Preferably, the susceptor element extends from the closed end of the chamber into the inductor coil and the chamber.

[0019] When at least a portion of the aerosol-generating article is received in the room, the sensor coil may be configured to receive the at least a portion of the aerosol-generating article within the sensor coil. Preferably, the sensor coil is configured such that the sensor coil contacts the aerosol-generating article when the aerosol-generating article is received within the sensor coil.

[0020] Advantageously, configuring the inductor coil to contact an aerosol-generating article received within the inductor coil can increase heating of the aerosol-generating article during use. For example, when an alternating current is provided to the inductor coil, the inductor coil typically exhibits a relatively small amount of resistive heating. Therefore, providing contact between the inductor coil and the aerosol-generating article can promote conductive heat transfer from the inductor coil to the aerosol-generating article.

[0021] Advantageously, configuring the inductor coil to contact an aerosol-generating article received within the inductor coil may facilitate retaining the aerosol-generating article within the aerosol-generating device during use. For example, the contact between the inductor coil and the aerosol-generating article may provide a desired degree of friction to reduce the risk of the aerosol-generating article sliding out of the chamber during use.

[0022] The housing may include at least one slot extending through the housing and communicating with the chamber. The inductor coil is exposed to the chamber through the slot such that the inductor coil contacts the aerosol-forming article received within the chamber. The inductor coil may extend partially through the slot and into the chamber.

[0023] The housing may include an outer housing portion and an inner housing portion, wherein the inner housing portion defines at least one slot. An outer surface of the inductor coil may abut an inner surface of the outer housing portion. The inductor coil may be formed of a resilient material to bias the outer surface of the inductor coil against the inner surface of the outer housing portion.

[0024] Advantageously, embodiments in which the inductor coil partially extends through at least one slot in the inner housing portion can facilitate retaining the inductor coil within the housing. For example, the inductor coil can be inserted into the chamber and extend into at least one slot and against the outer housing portion.

[0025] The inductor coil may be disposed within the chamber. That is, the inductor coil may be disposed substantially entirely within the chamber. The inner surface of the housing may at least partially define the chamber, wherein the outer surface of the inductor coil abuts the inner surface of the housing. The inductor coil may be formed of a resilient material to bias the outer surface of the inductor coil against the inner surface of the housing.

[0026] The housing may define a recess in the inner surface of the chamber. Preferably, the inner surface of the housing forms the recess. The inductor coil may be at least partially arranged within the recess. Advantageously, the recess may facilitate retaining the inductor coil within the chamber.

[0027] The recess may be pre-formed in the housing so that the inductor coil is inserted into the recess during assembly of the aerosol generating device. For example, the inductor coil may be inserted into the chamber and stretched into the recess. This may facilitate construction of the housing and the inductor coil in separate manufacturing processes.

[0028] The outer surface of the inductor coil may be overmolded with a portion of the housing, wherein the overmolded portion of the housing forms the recess. Advantageously, this integrates the manufacture of the housing and the assembly of the inductor coil with the housing into a single manufacturing step. For example, at least a portion of the housing may be formed by overmolding the housing over a preformed inductor coil. Advantageously, overmolding may facilitate retaining the inductor coil within the recess. For example, the overmolding step may bond the outer surface of the inductor coil to the housing.

[0029] The housing may define a chamber having a substantially constant cross-sectional shape along the length of the chamber. For example, the chamber may define a volume having a substantially cylindrical shape, such as a circular cylinder or an elliptical cylinder. The outer surface of the inductor coil may abut the inner surface of the chamber. The inductor coil may be formed of a resilient material to bias the outer surface of the inductor coil against the inner surface of the chamber. The outer surface of the inductor coil may be bonded to the inner surface of the chamber, for example using an adhesive.

[0030] In any of the embodiments described herein, each winding of the inductor coil can be spaced apart from an adjacent winding of the inductor coil. Advantageously, the spacing between adjacent windings can form a spiral channel between the windings of the inductor coil. Advantageously, the spiral channel can facilitate airflow through the chamber when an aerosol generating article is received in the chamber. For example, in an embodiment in which the inductor coil is configured to contact an aerosol generating article received in the inductor coil, airflow can pass along the spiral channel when the aerosol generating article is received in the inductor coil. Advantageously, the spacing between adjacent windings can be adjusted to provide a desired cross-sectional area for the spiral channel. Advantageously, this can, for example, provide a desired resistance to suction.

[0031] The inductor coil may be configured such that each winding of the inductor coil contacts an adjacent winding of the inductor coil. Advantageously, this eliminates gaps between adjacent windings of the inductor coil. Advantageously, this may reduce or eliminate the risk of contaminants or debris becoming lodged between the windings of the inductor coil. This is particularly advantageous because the inductor coil is arranged to contact an aerosol generating article received within the inductor coil. Advantageously, eliminating gaps between adjacent windings of the inductor coil increases the number of windings per unit length of the inductor coil, which increases the inductance of the inductor coil.

[0032] Preferably, the inductor coil is formed of an electrical wire comprising a conductive core and an outer layer surrounding the conductive core, the outer layer comprising an electrically insulating material. Advantageously, the outer layer prevents electrical shorting between adjacent windings of the inductor coil. Advantageously, the outer layer electrically isolates the inductor coil from an aerosol-generating article received within the inductor coil. The outer layer may comprise at least one of glass and ceramic.

[0033] The inductor coil may be formed from a wire having a substantially rectangular cross-sectional shape. As used herein, a rectangular shape may be any right-angled parallelogram, including a square. Preferably, the inductor coil is formed from a wire having a substantially square cross-sectional shape.

[0034] Advantageously, in embodiments where each winding contacts an adjacent winding, forming the inductor coil from a wire having a substantially rectangular cross-sectional shape can facilitate eliminating gaps between adjacent windings of the inductor coil. Preferably, a flat surface of each winding of the inductor coil contacts a flat surface of an adjacent winding of the inductor coil.

[0035] Preferably, the inductor coil defines a lumen extending through the inductor coil for receiving an aerosol generating article. In an embodiment in which the inductor coil is formed of a wire having a substantially rectangular cross-sectional shape and each winding contacts an adjacent winding, preferably, multiple consecutive windings of the inductor coil define a first portion of the lumen having a constant cross-sectional area. Advantageously, the first portion of the lumen having a constant cross-sectional area can form a smooth portion of the inner surface of the inductor coil. Advantageously, the smooth portion of the inner surface of the inductor coil can facilitate insertion of the aerosol generating article into the inductor coil. Advantageously, the smooth portion of the inner surface of the inductor coil can increase the contact area between the inductor coil and the aerosol generating article received within the inductor coil. Advantageously, this can facilitate retention of the aerosol generating article within the inductor coil.

[0036] Preferably, the lumen has a first end, a second end, and a length extending between the first end and the second end.

[0037] The lumen may have a substantially constant cross-sectional area along its length.

[0038] The inductor coil may be arranged within the housing such that an aerosol generating article inserted into the inductor coil enters the lumen through the first end of the lumen. In embodiments in which the inductor coil defines a first portion of the lumen having a constant cross-sectional area, the inductor coil may define a second portion of the lumen extending between the first portion of the lumen and the first end of the lumen, wherein the cross-sectional area of ​​the second portion increases in a direction from the first portion toward the first end. Advantageously, this may provide the lumen with a tapered cross-sectional area, which may facilitate insertion of the aerosol generating article into the inductor coil. Preferably, the cross-sectional area of ​​the lumen at the first end is greater than the cross-sectional area of ​​the lumen within the first portion. Preferably, the cross-sectional area of ​​the lumen within the first portion is substantially the same as the cross-sectional area of ​​a portion of the aerosol generating article configured for insertion into the inductor coil.

[0039] The first portion of the lumen may extend between the second portion of the lumen and the second end.

[0040] In embodiments where an outer surface of the inductor coil abuts an inner surface of a recess or chamber defined by the housing, preferably the change in cross-sectional profile of the recess or chamber corresponds to the change in cross-sectional profile of the lumen.

[0041] In embodiments where the aerosol generating device includes a susceptor element, the susceptor element may be formed of any material that can be inductively heated to a temperature sufficient to atomize the aerosol-forming substrate. Suitable materials for the susceptor element include graphite, molybdenum, silicon carbide, stainless steel, niobium and aluminum. Preferred susceptor elements include metal or carbon. Preferably, the susceptor element includes or consists of a ferromagnetic material, such as ferritic iron, ferromagnetic alloys (such as ferromagnetic steel or stainless steel), ferromagnetic particles and ferrites. Suitable susceptor elements may be or include aluminum. The susceptor element preferably includes greater than about 5%, preferably greater than about 20%, more preferably greater than about 50% or greater than 90% ferromagnetic or paramagnetic material. The preferred susceptor element may be heated to a temperature in excess of about 250 degrees Celsius.

[0042] The susceptor element may comprise a non-metallic core with a metallic layer disposed thereon.For example, the susceptor element may comprise one or more metallic tracks formed on an outer surface of a ceramic core or substrate.

[0043] The susceptor element may have a protective outer layer, such as a protective ceramic layer or a protective glass layer. The protective outer layer may encapsulate the susceptor element. The susceptor element may include a protective coating formed of glass, ceramic or an inert metal formed on a core of susceptor material.

[0044] The susceptor element may have any suitable cross-section. For example, the susceptor element may have a square, oval, rectangular, triangular, pentagonal, hexagonal, or similar cross-sectional shape. The susceptor element may have a flat or flat cross-sectional shape.

[0045] The susceptor element may be solid, hollow or porous. Preferably, the susceptor element is solid.

[0046] In embodiments where the susceptor element has a flat or flat cross-sectional shape, preferably, the susceptor element has a thickness of between about 1 mm and about 8 mm, more preferably between about 3 mm and about 5 mm. The thickness of the susceptor element is measured in the longitudinal direction of the aerosol generating device. Preferably, the susceptor element has a width or diameter of between about 3 mm and about 12 mm, more preferably between about 4 mm and about 10 mm, more preferably between about 5 mm and about 8 mm. The width or diameter of the susceptor element is orthogonal to its thickness.

[0047] In embodiments where the susceptor element is an elongated susceptor element, preferably, the elongated susceptor element is in the form of a pin, a rod, a blade or a plate. Preferably, the elongated susceptor element has a length between about 5 mm and about 15 mm, such as between about 6 mm and about 12 mm, or between about 8 mm and about 10 mm. The elongated susceptor element preferably has a width between about 1 mm and about 8 mm, more preferably between about 3 mm and about 5 mm. The elongated susceptor element may have a thickness of about 0.01 mm to about 2 mm. If the elongated susceptor element has a constant cross-section, such as a circular cross-section, it has a preferred width or diameter between about 1 mm and about 5 mm.

[0048] Preferably, the aerosol generating device is portable. The aerosol generating device may be of a size comparable to a conventional cigar or cigarette. The aerosol generating device may have an overall length of between about 30 mm and about 150 mm. The aerosol generating device may have an outer diameter of between about 5 mm and about 30 mm.

[0049] The aerosol generating device housing may be elongated. The housing may comprise any suitable material or combination of materials. Examples of suitable materials include metals, alloys, plastics or composite materials containing one or more of those materials, or thermoplastic materials suitable for food or pharmaceutical applications, such as polypropylene, polyetheretherketone (PEEK) and polyethylene. Preferably, the material is lightweight and non-brittle.

[0050] The housing may include a mouthpiece. The mouthpiece may include at least one air inlet and at least one air outlet. The mouthpiece may include more than one air inlet. The one or more air inlets may reduce the temperature of the aerosol before the aerosol is delivered to the user, and may reduce the concentration of the aerosol before the aerosol is delivered to the user.

[0051] Alternatively, a mouthpiece may be provided as part of the aerosol-generating article.

[0052] As used herein, the term "mouthpiece" refers to the part of an aerosol generating device that is placed in the mouth of a user for direct inhalation of an aerosol generated by the aerosol generating device from an aerosol generating article contained in a chamber of the housing.

[0053] The aerosol-generating device may comprise a user interface for activating the device, such as a button for initiating heating of the device or a display for indicating the status of the device or aerosol-forming substrate.

[0054] The aerosol generating device comprises a power source. The power source may be a battery, such as a rechargeable lithium ion battery. Alternatively, the power source may be another form of charge storage device, such as a capacitor. The power source may need to be recharged. The power source may have a capacity that allows sufficient energy to be stored for one or more uses of the device. For example, the power source may have sufficient capacity to allow continuous generation of aerosol for a period of about six minutes, corresponding to the typical time spent smoking a conventional cigarette, or for a period of multiple six minutes. In another example, the power source may have sufficient capacity to allow a predetermined number of puffs or discrete activations.

[0055] The power supply can be a DC power supply. In one embodiment, the power supply is a DC power supply having a DC power supply voltage in the range of about 2.5 volts to about 4.5 volts and a DC power supply current in the range of about 1 ampere to about 10 amperes (corresponding to a DC power supply between about 2.5 watts to about 45 watts).

[0056] The power supply can be configured to operate at a high frequency. As used herein, the term "high frequency oscillating current" refers to an oscillating current having a frequency between about 500 kilohertz and about 30 megahertz. The frequency of the high frequency oscillating current can be about 1 megahertz to about 30 megahertz, preferably about 1 megahertz to about 10 megahertz, and more preferably about 5 megahertz to about 8 megahertz.

[0057] The aerosol generating device includes a controller connected to the inductor coil and a power source. The controller is configured to control the supply of power to the inductor coil from the power source. The circuit may include a microprocessor, which may be a programmable microprocessor, a microcontroller or an application specific integrated chip (ASIC) or other circuit capable of providing control. The controller may include other electronic components. The controller may be configured to regulate the current supply to the inductor coil. The current may be continuously supplied to the inductor coil after the aerosol generating device is activated, or may be intermittently supplied, such as based on one puff after another. The controller may advantageously include a DC / AC inverter, which may include a Class D or Class E power amplifier.

[0058] According to a second aspect of the present invention, an aerosol generating system is provided. According to any embodiment described herein, the aerosol generating system comprises an aerosol generating device according to the first aspect of the present invention. The aerosol generating system also comprises an aerosol generating article having an aerosol-forming substrate and configured for use with the aerosol generating device.

[0059] The aerosol-generating article may comprise a susceptor element. In embodiments where the aerosol-generating device comprises a susceptor element, the susceptor element in the aerosol-generating article may be in addition to the susceptor element in the aerosol-generating device. Preferably, in embodiments where the aerosol-generating device does not comprise a susceptor element, the aerosol-generating article comprises a susceptor element.

[0060] The susceptor element may be located adjacent to the aerosol-forming substrate.Preferably, the susceptor is located within the aerosol-forming substrate.

[0061] The susceptor element may comprise any of the optional or preferred features described herein with reference to the first aspect of the invention.

[0062] Aerosol-forming substrates may include nicotine. Nicotine-containing aerosol-forming substrates may be nicotine salt substrates. Aerosol-forming substrates may include plant-based materials. Aerosol-forming substrates may include tobacco. Aerosol-forming substrates may include tobacco-containing materials, including volatile tobacco flavoring compounds released from the aerosol-forming substrate when heated. Alternatively, aerosol-forming substrates may include non-tobacco materials. Aerosol-forming substrates may include homogenized plant-based materials. Aerosol-forming substrates may include homogenized tobacco materials. Homogenized tobacco materials may be formed by agglomerating particle tobacco. In a particularly preferred embodiment, aerosol-forming substrates include the gathered curled sheets of homogenized tobacco materials. As used herein, the term "embossed sheet" means a sheet with a plurality of substantially parallel ridges or wrinkles.

[0063] The aerosol-forming substrate may include at least one aerosol-forming agent. The aerosol-forming agent is any suitable known compound or a mixture of compounds, which is conducive to forming a dense and stable aerosol in use and is substantially resistant to thermal degradation at the operating temperature of the system. Suitable aerosol-forming agents are well known in the art and include, but are not limited to: polyols, such as triethylene glycol, 1,3-butylene glycol and glycerol; esters of polyols, such as glycerol mono-, di- or triacetate; and fatty acid esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanoate and dimethyl tetradecanoate. Preferred aerosol-forming agents are polyols or mixtures thereof, such as triethylene glycol, 1,3-butylene glycol. Preferably, the aerosol-forming agent is glycerol. If present, the aerosol-forming agent content of the homogenized tobacco material may be equal to or greater than 5 weight percents by dry weight, preferably about 5 weight percent to about 30 weight percents by dry weight. The aerosol-forming substrate may include other additives and ingredients, such as flavors.

[0064] In any of the above embodiments, the aerosol-generating article and the chamber of the aerosol-generating device may be arranged such that the article is partially received in the chamber of the aerosol-generating device.The chamber of the aerosol-generating device and the aerosol-generating article may be arranged such that the article is fully received in the chamber of the aerosol-generating device.

[0065] The aerosol-generating article may be substantially cylindrical in shape. The aerosol-generating article may be substantially elongated. The aerosol-generating article may have a length and a circumference substantially perpendicular to the length. The aerosol-forming substrate may be provided as an aerosol-forming segment comprising the aerosol-forming substrate. The aerosol-forming segment may be substantially cylindrical in shape. The aerosol-forming segment may be substantially elongated. The aerosol-forming segment may also have a length and a circumference substantially perpendicular to the length.

[0066] The aerosol-generating article may have an overall length of between about 30 mm and about 100 mm. In one embodiment, the aerosol-generating article has an overall length of about 45 mm. The aerosol-generating article may have an outer diameter of between about 5 mm and about 12 mm. In one embodiment, the aerosol-generating article may have an outer diameter of about 7.2 mm.

[0067] The aerosol-forming substrate may be provided as an aerosol-forming segment having a length between about 7 mm and about 15 mm. In one embodiment, the aerosol-forming segment may have a length of about 10 mm. Alternatively, the aerosol-forming segment may have a length of about 12 mm.

[0068] The aerosol generating segment preferably has an outer diameter that is substantially equal to the outer diameter of the aerosol generating article. The outer diameter of the aerosol generating segment may be between about 5 mm and about 12 mm. In one embodiment, the aerosol generating segment may have an outer diameter of about 7.2 mm.

[0069] The aerosol generating article may include a filter segment. The filter segment may be located at the downstream end of the aerosol generating article. The filter segment may be a cellulose acetate filter segment. In one embodiment, the filter segment has a length of about 7 mm, but it may have a length between about 5 mm and about 10 mm.

[0070] The aerosol-generating article may include an outer paper wrapper. Furthermore, the aerosol-generating article may include a spacing between the aerosol-forming substrate and the filter segment. The spacing may be about 18 mm, but may be in the range of about 5 mm to about 25 mm.

[0071] According to a third aspect of the present invention, there is provided an aerosol generating system, comprising an aerosol generating device, a sensor element and an aerosol generating article comprising an aerosol-forming substrate. The aerosol generating device comprises a housing and an inductor coil arranged in the housing, the inductor coil being used to receive at least a portion of the aerosol generating article in the inductor coil, so that when the aerosol generating article is received in the inductor coil, the inductor coil contacts the aerosol generating article. The inductor element is configured to cause at least a portion of the inductor element to be arranged in the inductor coil. The aerosol generating device also comprises a power supply and a controller, the controller being connected to the inductor coil and being configured to provide an alternating current to the inductor coil, so that in use, the inductor coil generates an alternating magnetic field to inductively heat the inductor element and thereby heat at least a portion of the aerosol generating article received in the inductor coil.

[0072] The aerosol generating device may comprise any of the optional or preferred features described herein with reference to the first aspect of the invention.

[0073] The aerosol-generating article may comprise any of the optional or preferred features described herein with reference to the second aspect of the invention.

[0074] According to a fourth aspect of the present invention, there is provided an aerosol generating device comprising a housing and an inductor coil arranged in the housing, the inductor coil being used to receive at least a portion of an aerosol generating article in the inductor coil, such that when the aerosol generating article is received in the inductor coil, the inductor coil contacts the aerosol generating article. The aerosol generating device also comprises a power supply and a controller connected to the inductor coil and configured to provide an alternating current to the inductor coil, such that in use, the inductor coil generates an alternating magnetic field to inductively heat the susceptor element and thereby heat at least a portion of the aerosol generating article received in the inductor coil.

[0075] Advantageously, configuring the inductor coil to contact an aerosol-generating article received within the inductor coil can increase heating of the aerosol-generating article during use. For example, when an alternating current is provided to the inductor coil, the inductor coil typically exhibits a relatively small amount of resistive heating. Therefore, providing contact between the inductor coil and the aerosol-generating article can promote conductive heat transfer from the inductor coil to the aerosol-generating article.

[0076] Advantageously, configuring the inductor coil to contact an aerosol-generating article received within the inductor coil may facilitate retaining the aerosol-generating article within the aerosol-generating device during use. For example, the contact between the inductor coil and the aerosol-generating article may provide a desired degree of friction to reduce the risk of the aerosol-generating article sliding out of the chamber during use.

[0077] Advantageously, arranging the inductor coil to contact the aerosol-generating article received within the inductor coil can reduce or minimize the distance between the inductor coil and the susceptor element. Advantageously, arranging the inductor coil to contact the aerosol-generating article received within the inductor coil eliminates any intermediate material between the inductor coil and the aerosol-generating article. Advantageously, one or both of these features can maximize the inductive energy transfer from the inductor coil to the susceptor element. This can be particularly important in embodiments where the susceptor element is positioned inside the aerosol-generating article during use.

[0078] The aerosol generating device may comprise a chamber. The housing may at least partially define the chamber. Preferably, the chamber comprises an open end through which the aerosol generating article is inserted into the inductor coil. Preferably, the chamber comprises a closed end opposite the open end. During use, when the aerosol generating article is received within the inductor coil, the aerosol generating article is received within the chamber.

[0079] Advantageously, the chamber may facilitate assembly of the aerosol generating device.In particular, the chamber may retain the inductor coil in a desired position within the housing.

[0080] The inductor coil may be arranged at least partially within the chamber.

[0081] The aerosol generating device may comprise any of the optional or preferred features described herein with reference to the first aspect of the invention.

[0082] According to a fifth aspect of the present invention, an aerosol generating system is provided. According to any embodiment described herein, the aerosol generating system comprises an aerosol generating device according to the fourth aspect of the present invention. The aerosol generating system also comprises an aerosol generating article having an aerosol-forming substrate and configured for use with the aerosol generating device. The aerosol generating article may comprise any of the optional or preferred features described herein with reference to the second aspect of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] The invention will now be further described, by way of example only, with reference to the accompanying drawings, in which:

[0084] Figure 1 shows a perspective view of an aerosol generating system according to a first embodiment of the present invention;

[0085] Figure 2 Shows Figure 1 A perspective view of an aerosol generating system of , wherein the aerosol generating article is inserted into the aerosol generating device;

[0086] Figure 3 Shows Figure 1 A cross-sectional view of an aerosol generating device of an aerosol generating system;

[0087] Figure 4 Shows Figure 2 A cross-sectional view of an aerosol generating system;

[0088] Figure 5 shows a cross-sectional view of an aerosol generating device according to a second embodiment of the present invention;

[0089] Figure 6 shows a cross-sectional view of an aerosol generating device according to a third embodiment of the present invention;

[0090] Figure 7 showing a perspective view of an alternative inductor coil arrangement according to the present invention;

[0091] Figure 8 a cross-sectional view showing another alternative inductor coil arrangement according to the present invention; and

[0092] Fig. 9 A cross-sectional view of yet another alternative inductor coil arrangement according to the present invention is shown. DETAILED DESCRIPTION

[0093] Figures 1 to 4 An aerosol generating system 10 according to a first embodiment of the invention is shown. The aerosol generating system 10 comprises an aerosol generating device 12 and an aerosol generating article 14.

[0094] The aerosol-generating device 12 includes a housing 16 defining a chamber 18 for receiving a portion of an aerosol-generating article 14. The chamber 18 includes an open end 20 and a closed end 22 opposite the open end 20, wherein the aerosol-generating article 14 is inserted into the chamber 18 through the open end. A susceptor element 24 extends from the closed end 22 of the chamber 18 for insertion into the aerosol-generating article 14.

[0095] The aerosol generating device 12 also includes an inductor coil 26 including a plurality of windings 28 disposed within the chamber 18 and extending around the susceptor element 24. Positioning the inductor coil 26 within the chamber 18 reduces the distance between the inductor coil 26 and the susceptor element 24. Positioning the inductor coil 26 within the chamber 18 also eliminates any portion of the housing 16 between the inductor coil 26 and the susceptor element 24.

[0096] The housing 16 , chamber 18 , inductor coil 26 and susceptor element 24 are arranged concentrically with respect to a central axis 29 of the aerosol generating device 12 .

[0097] The aerosol generating device 12 further comprises a controller 30 and a power source 32 connected to the inductor coil 26. The controller 30 is configured to provide an alternating current from the power source 32 to the inductor coil 26 to generate an alternating magnetic field which inductively heats the susceptor element 24.

[0098] The aerosol-generating article 14 includes an aerosol-forming substrate 34 in the form of a tobacco rod, a hollow acetate tube 36, a polymeric filter 38, a mouthpiece 40, and an outer wrapper 42. During use, a portion of the aerosol-generating article 14 is inserted into the chamber 18 and the inductor coil 26 so that the aerosol-generating article 14 contacts the inductor coil 26. When the aerosol-generating article 14 is inserted into the chamber 18, the susceptor element 24 is inserted into the aerosol-forming substrate 34. The controller 30 provides an alternating current to the inductor coil 26 to inductively heat the susceptor 24, which heats the aerosol-forming substrate 34 to generate an aerosol. The aerosol-generating device 12 includes an air inlet 44 that extends through the housing 16 and provides fluid communication between the exterior of the aerosol-generating device 12 and the chamber 18 adjacent the closed end 22. During use, a user inhales into the mouthpiece 40 of the aerosol-generating article 14 to draw an airflow into the chamber 18 via the air inlet 44. The airflow then flows into the aerosol-forming substrate 34 where the aerosol is entrained in the airflow. The airflow and aerosol then flow through the hollow acetate tube 36, the polymer filter 38 and the mouthpiece 40 for delivery to the user.

[0099] Figure 5 1 shows a cross-sectional view of an aerosol generating device 112 according to a second embodiment of the present invention. The aerosol generating device 112 is similar to the aerosol generating device 112 of reference Figures 1 to 4 The aerosol generating device 12 is described above and like reference numerals are used to indicate like parts.

[0100] The aerosol generating device 112 includes a housing 116 having an inner housing portion 117 defining a chamber 18 and an outer housing portion 119 spaced apart from the inner housing portion 117. The housing 116 also includes an annular slot 121 within the inner housing portion 117 and communicating with the chamber 18. The inductor coil 26 is disposed within the slot 121 such that the inductor coil 26 partially extends into the chamber 18. The outer surface of the inductor coil 26 abuts against the inner surface of the outer housing portion 119. The aerosol generating device 112 may be used with reference to Figures 1 to 4 The described aerosol-generating article 14 is incorporated, and the operation of the aerosol-generating device 112 is the same as the operation of the aerosol-generating device 12 .

[0101] Figure 6 FIG. 2 shows a cross-sectional view of an aerosol generating device 212 according to a third embodiment of the present invention. The aerosol generating device 212 is similar to the aerosol generating device 212 of FIG. Figure 5 The aerosol generating device 112 is described herein and like reference numerals are used to indicate like parts.

[0102] The aerosol generating device 212 comprises a housing 216 comprising an inner housing portion 217 overmolded relative to the inductor coil 26 to form a recess 223, in which the inductor coil 26 is arranged such that the inductor coil 26 partially extends into the chamber 18. An outer surface of the inductor coil 26 abuts a portion of the inner housing portion 217 forming the recess 223. The aerosol generating device 112 may be used with reference to Figures 1 to 4 The described aerosol-generating article 14 is incorporated, and the operation of the aerosol-generating device 112 is the same as the operation of the aerosol-generating device 12 .

[0103] Figure 7 An alternative inductor coil 326 is shown which may replace the inductor coil 26 with the reference Figures 1 to 6 The inductor coil 326 may be used with any aerosol generating device described herein. Each winding 328 of the inductor coil 326 contacts adjacent windings 328 to eliminate gaps between windings 328. This reduces or prevents contaminants or debris from becoming lodged between windings 328 and increases the inductance of the inductor coil 328. To prevent electrical shorting between adjacent windings 328, the inductor coil 326 is formed of a wire coated with an electrically insulating outer layer 329.

[0104] Figure 8 4 shows a cross-sectional view of another alternative inductor coil 426. In addition to the inductor coil 426 being formed of a wire having a square cross-sectional shape, the inductor coil 426 is similar to Figure 7 The inductor coil 326 shown is substantially identical. The inductor coil 426 defines a lumen 431 extending through the inductor coil 426 for receiving a portion of the aerosol generating article 14. The windings 428 of the inductor coil 426 have the same diameter so that the cross-sectional area of ​​the lumen 431 remains constant along the central axis 29. As a result of this arrangement, the inner surface 433 of the inductor coil 426 is substantially smooth along the central axis 29.

[0105] Fig. 9 A cross-sectional view of yet another alternative inductor coil 526 is shown. The inductor coil 526 is similar to the reference Figure 8 The inductor coil 526 is described in detail. The inductor coil 526 differs in that it includes a first section 535 in which the cross-sectional area 536 of the lumen 431 remains constant and a second section 537 in which the cross-sectional area 538 of the lumen 431 increases in a direction away from the first section 535. The larger cross-sectional area of ​​the lumen 431 in the second section 537 can facilitate insertion of the aerosol-generating article 14 into the lumen 431.

Claims

1. An aerosol generating device, comprising: a housing defining a chamber for receiving at least a portion of an aerosol-generating article; an inductor coil disposed at least partially within the chamber; as well as a power source and a controller connected to the inductor coil and configured to provide an alternating current to the inductor coil so that, in use, the inductor coil generates an alternating magnetic field to inductively heat a susceptor element and thereby heat at least a portion of an aerosol-generating article received within the inductor coil.

2. An aerosol generating device according to claim 1, further comprising an elongated susceptor element arranged at least partially within the inductor coil.

3. An aerosol-generating device according to claim 1, wherein the inductor coil is configured to receive at least a portion of an aerosol-generating article within the inductor coil.

4. An aerosol-generating device according to claim 3, wherein the inductor coil is configured such that when an aerosol-generating article is received within the inductor coil, the inductor coil contacts the aerosol-generating article.

5. An aerosol generating device according to claim 1, wherein the housing defines a recess in the inner surface of the chamber, and wherein the inductor coil is at least partially disposed within the recess.

6. An aerosol generating device according to claim 5, wherein an outer surface of the inductor coil is overmoulded with a portion of the housing, and wherein the overmoulded portion of the housing forms the recess.

7. An aerosol generating device according to claim 1, wherein the inductor coil is formed from a resilient material such that the windings of the inductor coil are biased against an inner surface of the chamber.

8. An aerosol generating device according to claim 1, wherein each winding of the inductor coil is spaced apart from an adjacent winding of the inductor coil.

9. An aerosol generating device according to claim 8, wherein the spacing between adjacent windings of the inductor coil forms a spiral airflow channel.

10. An aerosol generating device according to claim 1, wherein each winding of the inductor coil contacts an adjacent winding of the inductor coil.

11. An aerosol generating device according to claim 10, wherein the inductor coil is formed from an electrical wire comprising a conductive core and an outer layer surrounding the conductive core, the outer layer comprising an electrically insulating material.

12. An aerosol generating device according to claim 1, wherein the inductor coil is formed from a wire having a rectangular cross-sectional shape.

13. An aerosol generating device according to claim 12, wherein the planar surface of each winding of the inductor coil contacts the planar surface of an adjacent winding of the inductor coil.

14. An aerosol generating device according to claim 13, wherein the inductor coil defines a lumen extending through the inductor coil for receiving an aerosol generating article, and wherein a plurality of consecutive windings of the inductor coil define a first portion of the lumen, the first portion having a constant cross-sectional area.

15. An aerosol generating device according to claim 14, wherein the lumen has a first end, a second end and a length extending between the first end and the second end, and wherein the lumen has a constant cross-sectional area along its length.

16. An aerosol generating device according to claim 14, wherein the inductor coil is arranged in the shell so that an aerosol generating article inserted into the inductor coil enters the tubular cavity through the first end of the tubular cavity, wherein a second portion of the tubular cavity extends between the first portion of the tubular cavity and the first end of the tubular cavity, and wherein a cross-sectional area of ​​the second portion increases in a direction from the first portion toward the first end.

17. An aerosol generating device according to claim 16, wherein the lumen has a second end opposite the first end, and wherein the first portion of the lumen extends between the second portion of the lumen and the second end.

18. An aerosol generating system comprising an aerosol generating device according to any one of the preceding claims and an aerosol generating article having an aerosol-forming substrate and configured for use with the aerosol generating device.

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