Aerosol generating device having an inductor coil with a reduced separation section

Abstract

An aerosol generating device is provided that improves energy transfer from an inductor to a susceptor element. [Solution] An aerosol generating device (12) is provided that includes a housing (16) that defines a chamber (18) for receiving at least a portion of an aerosol-generating article (14), and an inductor coil (26) disposed within the chamber (18.) The aerosol generating device (12) also includes a power supply (32) and 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) generates an alternating magnetic field that inductively heats the susceptor element (24), thereby heating at least a portion of the aerosol-generating article (14) received within the inductor coil (26).

Description

[Technical field]

[0001] 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 in the aerosol generating device. [Background technology]

[0002] Numerous electrically operated aerosol generating systems have been proposed in the art in which an aerosol generating device having an electric heater is used to heat an aerosol-forming substrate such as a tobacco plug. One purpose of such aerosol generating systems is to reduce well-known harmful smoke components of the type produced by the combustion and pyrolysis of tobacco in conventional cigarettes. Typically, the aerosol-generating substrate is provided as part of an aerosol-generating article that is inserted into a chamber or cavity of the aerosol generating device. In some known systems, 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 order to heat the aerosol-forming substrate to a temperature capable of releasing volatile components capable of forming an aerosol. In other aerosol generating systems, an induction heater is used rather than a resistive heating element. An induction heater typically comprises an inductor forming part of the aerosol generating device and an electrically conductive susceptor element disposed in the aerosol generating device and in thermal proximity to the aerosol-forming substrate. During use, the inductor generates an alternating magnetic field which creates eddy currents and hysteresis losses in the susceptor element, causing heating of the susceptor element and thereby heating the aerosol-forming substrate. Summary of the Invention [Problem to be solved by the invention]

[0003] Inductive heating systems rely on inductive energy transfer from an inductor to a susceptor element, and it would be desirable to provide an aerosol generating device that improves the energy transfer from the inductor to the susceptor element. [Means for solving the problem]

[0004] According to a first aspect of the present invention, there is provided an aerosol generating apparatus comprising a housing defining a chamber for receiving at least a portion of an aerosol-generating article, and an inductor coil at least partially disposed within the chamber, The aerosol generating apparatus 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 chamber.

[0005] As used herein, the term "longitudinal" is used to describe a direction along the major axis of the aerosol-generating device or article, and the term "transverse" is used to describe a direction perpendicular to the longitudinal axis. When referring to a chamber or inductor coil, the term "longitudinal" refers to the direction in which the aerosol-generating article is inserted into the chamber or 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 inductor coil.

[0006] As used herein, the term "width" refers to the major transverse dimension of an aerosol-generating device, or of a component of an aerosol-generating article, at a particular location along its length. The term "thickness" refers to the transverse dimension of an aerosol-generating device, or of a component of an aerosol-generating article, perpendicular to the width.

[0007] The term "aerosol-forming substrate" as used herein relates to a substrate capable of releasing volatile compounds capable of forming an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate. The aerosol-forming substrate is part of an aerosol-generating article.

[0008] The term "aerosol-generating article" as used herein refers to an article that includes an aerosol-forming substrate capable of releasing a volatile compound capable of forming an aerosol. For example, the aerosol-generating article may be an article that generates an aerosol that can be directly inhaled by a user sucking or puffing on a mouthpiece at the proximal or user end of the system. The aerosol-generating article may be disposable. An article that includes an aerosol-forming substrate that includes tobacco is called a tobacco stick.

[0009] As used herein, the term "aerosol-generating device" refers to a device that interacts with an aerosol-generating article to generate an aerosol.

[0010] 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 which the aerosol-generating article and the aerosol-generating device cooperate to generate a respirable aerosol.

[0011] As used herein, the term "elongated" refers to a component having a length that is greater than (eg, twice) both its width and thickness.

[0012] As used herein, "susceptor element" means a conductive element that heats up when subjected to a changing magnetic field. This may be the result of eddy currents induced in the susceptor element, or hysteresis losses, or both eddy currents and hysteresis losses. In use, the susceptor element is located in thermal contact or in thermal proximity with an aerosol-forming substrate of an aerosol-generating article received within an inductor coil of an aerosol-generating device. In this way, the aerosol-forming substrate is heated by the susceptor element during use such that an aerosol is formed. The susceptor element may form part of the aerosol-generating device or part of the aerosol-generating article.

[0013] 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, the use of inductive heating rather than resistive heating may provide improved energy conversion.

[0014] Advantageously, locating the inductor coil at least partially within the chamber may reduce or minimize the distance between the inductor coil and the susceptor element. Advantageously, locating the inductor coil at least partially within the chamber may eliminate any intervening material between the inductor coil and the aerosol-generating article. Advantageously, one or both of these features may maximize inductive energy transfer from the inductor coil to the susceptor element. This may be particularly advantageous in embodiments where the susceptor element is positioned inside the aerosol-generating article during use.

[0015] The aerosol-generating article may comprise a susceptor element disposed at least partially within the 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 robust aerosol-generating article. Aerosol-generating articles are typically disposable and are manufactured in much larger quantities than the aerosol-generating devices in which they are operated. As a result, reducing the cost of the article (even if it requires more expensive equipment) can result in significant cost savings for both manufacturers and consumers.

[0016] The susceptor element is preferably an elongated susceptor element that is preferably arranged for insertion into the aerosol-generating article when the aerosol-generating article is inserted into the inductor coil. Advantageously, an elongated susceptor element arranged for insertion into the aerosol-generating article may optimize heat transfer from the susceptor element to the aerosol-forming substrate of the aerosol-generating article.

[0017] The susceptor element preferably extends from the closed end of the chamber into the inductor coil and into the chamber.

[0018] The inductor coil may be configured to receive at least a portion of the aerosol-generating article therein when at least a portion of the aerosol-generating article is received in the chamber. Preferably, the inductor coil is configured such that the inductor coil contacts the aerosol-generating article when the aerosol-generating article is received in the inductor coil.

[0019] Advantageously, configuring the inductor coil to contact an aerosol-generating article received therein may increase heating of the aerosol-generating article during use. For example, inductor coils typically exhibit a relatively small amount of resistive heating when an alternating current is provided to the inductor coil. Thus, providing contact between the inductor coil and the aerosol-generating article may facilitate conductive heat transfer from the inductor coil to the aerosol-generating article.

[0020] Advantageously, configuring the inductor coil to contact an aerosol-generating article received therein may facilitate retention of the aerosol-generating article within the aerosol generating device during use For example, 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.

[0021] The housing may include at least one slot extending through the housing and in communication with the chamber. The inductor coil is exposed to the chamber through the slot such that the inductor coil contacts an aerosol-forming article received in the chamber. The inductor coil may extend partially into the chamber through the slot.

[0022] The housing may include an outer housing portion and an inner housing portion, the inner housing portion defining 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 from a resilient material to bias the outer surface of the inductor coil against the inner surface of the outer housing portion.

[0023] Advantageously, embodiments in which the inductor coil extends partially through the at least one slot in the inner housing portion may facilitate retention of the inductor coil within the housing. For example, the inductor coil may be inserted into the chamber, extended into the at least one slot, and extended relative to the outer housing portion.

[0024] The inductor coil may be disposed within the chamber. That is, the inductor coil may be disposed substantially completely within the chamber. An inner surface of the housing may at least partially define the chamber, and an outer surface of the inductor coil abuts the inner surface of the housing. The inductor coil may be formed from a resilient material to bias the outer surface of the inductor coil against the inner surface of the housing.

[0025] The housing may define a recess in an inner surface of the chamber. The inner surface of the housing preferably forms the recess. The inductor coil may be at least partially disposed within the recess. Advantageously, the recess may facilitate retention of the inductor coil within the chamber.

[0026] The recess may be pre-formed in the housing such 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 expanded into the recess. This may facilitate construction of the housing and the inductor coil in separate manufacturing processes.

[0027] An outer surface of the inductor coil may be overmolded onto a portion of the housing, the overmolded portion of the housing forming the recess. Advantageously, this integrates manufacturing the housing and assembling the inductor coil with the housing into a single manufacturing process. For example, at least a portion of the housing may be formed by overmolding the housing over a pre-formed inductor coil. Advantageously, the overmolding may facilitate retention of the inductor coil within the recess. For example, the overmolding process may bond the outer surface of the inductor coil to the housing.

[0028] The housing may define a chamber having a substantially constant cross-sectional shape along a length of the chamber. For example, the chamber may define a volume having a substantially cylindrical shape, such as a circular cylindrical shape or an elliptical cylindrical shape. An outer surface of the inductor coil may abut an inner surface of the chamber. The inductor coil may be formed from 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 adhered to the inner surface of the chamber, for example, using an adhesive.

[0029] In any of the embodiments described herein, each winding of the inductor coil may be spaced apart from an adjacent winding of the inductor coil. Advantageously, the spacing between adjacent windings may form a helical channel between the windings of the inductor coil. Advantageously, the helical channel may 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 therein, airflow may pass along the helical channel when an aerosol-generating article is received therein. Advantageously, the spacing between adjacent windings may be adjusted to provide a desired cross-sectional area for the helical channel. Advantageously, this may provide a desired pull-out resistance, for example.

[0030] 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 trapped between the windings of the inductor coil. This is particularly advantageous as 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.

[0031] The inductor coil is formed from a wire having a conductive core and an outer layer surrounding the conductive core, the outer layer preferably comprising an electrically insulating material. Advantageously, the outer layer prevents electrical shorting between adjacent windings of the inductor coil. Advantageously, the outer layer electrically insulates the inductor coil from an aerosol-generating article received within the inductor coil. The outer layer may comprise at least one of a glass and a ceramic.

[0032] 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.

[0033] Advantageously, forming the inductor coil from wire having a substantially rectangular cross-sectional shape may facilitate eliminating gaps between adjacent turns of the inductor coil in embodiments in which each turn contacts an adjacent turn, with the planar surface of each turn of the inductor coil preferably contacting the planar surface of the adjacent turn of the inductor coil.

[0034] The inductor coil preferably defines a lumen extending therethrough for receiving an aerosol-generating article. In embodiments where the inductor coil is formed from a wire having a substantially rectangular cross-sectional shape and where each winding contacts an adjacent winding, the plurality of successive windings of the inductor coil preferably defines 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 may form a smooth portion of the inner surface of the inductor coil. Advantageously, the smooth portion of the inner surface of the inductor coil may facilitate insertion of the aerosol-generating article into the inductor coil. Advantageously, the smooth portion of the inner surface of the inductor coil may increase the contact area between the inductor coil and an aerosol-generating article received therein. Advantageously, this may facilitate retention of the aerosol-generating article within the inductor coil.

[0035] The lumen preferably has a first end, a second end, and a length extending between the first and second ends.

[0036] The lumen may have a substantially constant cross-sectional area along its length.

[0037] The inductor coil may be disposed within the housing such that an aerosol-generating article inserted into the inductor coil enters the lumen through a 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, the cross-sectional area of ​​the second portion increasing in a direction from the first portion towards the first end. Advantageously, this may provide the lumen with a tapered cross-sectional area that may facilitate inserting the aerosol-generating article into the inductor coil. The cross-sectional area of ​​the lumen at the first end is preferably larger than the cross-sectional area of ​​the lumen in the first portion. The cross-sectional area of ​​the lumen in the first portion is preferably substantially the same as the cross-sectional area of ​​a portion of the aerosol-generating article configured for insertion into the inductor coil.

[0038] The first portion of the lumen may extend between the second portion and the second end of the lumen.

[0039] In embodiments in which the outer surface of the inductor coil abuts the inner surface of a recess or chamber defined by the housing, the change in cross-sectional profile of the recess or chamber preferably corresponds to a change in the cross-sectional profile of the lumen.

[0040] In embodiments where the aerosol generating device includes a susceptor element, the susceptor element may be formed from any material that can be inductively heated to a temperature sufficient to aerosolize the aerosol-forming substrate. Suitable materials for the susceptor element include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminum. Preferred susceptor elements include metal or carbon. The susceptor element preferably includes or consists of a ferromagnetic material, such as a ferromagnetic alloy, e.g., ferritic iron, ferromagnetic steel or stainless steel, ferromagnetic particles, ferrite, etc. Suitable susceptor elements may be or include aluminum. The susceptor element preferably includes more than about 5% ferromagnetic or paramagnetic material, preferably more than about 20% ferromagnetic or paramagnetic material, and more preferably more than about 50% or more than 90% ferromagnetic or paramagnetic material. Preferred susceptor elements may be heated to a temperature of greater than about 250 degrees Celsius.

[0041] The susceptor element may include a non-metallic core having a metallic layer disposed thereon. For example, the susceptor element may include one or more metallic tracks formed on the outer surface of a ceramic core or substrate.

[0042] The susceptor element may have a protective outer layer, such as a protective ceramic or 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 over a core of susceptor material.

[0043] The susceptor elements may have any suitable cross-section. For example, the susceptor elements may have a square, oval, rectangular, triangular, pentagonal, hexagonal or similar cross-sectional shape. The susceptor elements may have a planar or flat cross-sectional shape.

[0044] The susceptor elements may be solid, hollow or porous, preferably the susceptor elements are solid.

[0045] In embodiments in which the susceptor element has a planar or flat cross-sectional shape, the susceptor element preferably has a thickness of about 1 millimeter to about 8 millimeters, more preferably about 3 millimeters to about 5 millimeters. The thickness of the susceptor element is measured along the longitudinal axis of the aerosol generating device. The susceptor element preferably has a width or diameter of about 3 millimeters to about 12 millimeters, more preferably about 4 millimeters to about 10 millimeters, and more preferably about 5 millimeters to about 8 millimeters. The width or diameter of the susceptor element is perpendicular to its thickness.

[0046] In embodiments where the susceptor element is an elongated susceptor element, the elongated susceptor element is preferably in the form of a pin, rod, blade, or plate. The elongated susceptor element preferably has a length of 5 mm to 15 mm, for example 6 mm to 12 mm, or 8 mm to 10 mm. The elongated susceptor element preferably has a width of about 1 meter to about 8 mm, more preferably about 3 mm to about 5 mm. The elongated susceptor element may have a thickness of about 0.01 mm to about 2 mm. When the elongated susceptor element has a constant cross-section, for example a circular cross-section, it has a preferred width or diameter of 1 mm to 5 mm.

[0047] The aerosol generating device is preferably portable. The aerosol generating device may have a size comparable to a conventional cigar or cigarette. The aerosol generating device may have a total length of about 30 mm to about 150 mm. The aerosol generating device may have an outer diameter of about 5 mm to about 30 mm.

[0048] 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 composites containing one or more of these materials, or thermoplastics suitable for food or pharmaceutical applications, such as polypropylene, polyetheretherketone (PEEK), and polyethylene. Preferably, the material is light and not brittle.

[0049] The housing may comprise a mouthpiece. The mouthpiece may comprise at least one air inlet and at least one air outlet. The mouthpiece may comprise two or more air inlets. One or more of the air inlets may reduce the temperature of the aerosol before it is delivered to the user and may reduce the concentration of the aerosol before it is delivered to the user.

[0050] Alternatively, the mouthpiece may be provided as part of the aerosol-generating article.

[0051] As used herein, the term "mouthpiece" refers to a portion of an aerosol generating device that is placed in a user's mouth to directly inhale the aerosol generated by the aerosol generating device from an aerosol-generating article received within the chamber of the housing.

[0052] The aerosol generating device may include a user interface for activating the device, such as a button to initiate heating of the device, or a display to indicate the status of the device or the aerosol-forming substrate.

[0053] The aerosol generating device may include 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 require recharging. The power source may have a capacity that allows for the storage of sufficient energy for one or more uses of the device. For example, the power source may have a capacity sufficient to allow continuous generation of aerosol for approximately 6 minutes, or a multiple of 6 minutes, corresponding to the typical time it takes to smoke one conventional cigarette. In another embodiment, the power source may have a capacity sufficient to allow a predetermined number of puffs, or discontinuous activation.

[0054] The power source may be a DC power source, hi one embodiment, the power source is a DC power source having a DC supply voltage in the range of about 2.5 volts to about 4.5 volts, and a DC supply current in the range of about 1 amp to about 10 amps (corresponding to a DC power range of about 2.5 watts to about 45 watts).

[0055] The power source may 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 of about 500 kilohertz to about 30 megahertz. The high frequency oscillating current may have a frequency of 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.

[0056] The aerosol generating device comprises a controller connected to the inductor coil and a power supply. The controller is configured to control the supply of power from the power supply to the inductor coil. The controller may comprise a microprocessor, which may be a programmable microprocessor, a microcontroller, or an application specific integrated circuit chip (ASIC) or other electronic circuit capable of providing control. The controller may comprise further electronic components. The controller may be configured to regulate the supply of current to the inductor coil. The current may be supplied to the inductor coil continuously after activation of the aerosol generating device, or may be supplied intermittently (e.g., after every puff). The controller may advantageously comprise a DC / AC inverter, which may comprise a class D or class E power amplifier.

[0057] According to a second aspect of the invention there is provided an aerosol generation system comprising an aerosol generation device according to the first aspect of the invention, according to any of the embodiments described herein, and also comprising an aerosol-generating article having an aerosol-forming substrate and configured for use with the aerosol generation device.

[0058] The aerosol-generating article may comprise a susceptor element. In embodiments in which the aerosol-generating device comprises a susceptor element, the susceptor element in the aerosol-generating article may be an additional susceptor element separate from the susceptor element in the aerosol-generating device. The aerosol-generating article preferably comprises a susceptor element in embodiments in which the aerosol-generating device does not comprise a susceptor element.

[0059] The susceptor element may be positioned adjacent to the aerosol-forming substrate. Preferably, the susceptor is positioned within the aerosol-forming substrate.

[0060] The susceptor element may comprise any of the optional or preferred features described herein in relation to the first aspect of the invention.

[0061] The aerosol-forming substrate may comprise nicotine. The nicotine-containing aerosol-forming substrate may be a nicotine salt matrix. The aerosol-forming substrate may comprise a plant-derived material. The aerosol-forming substrate may comprise tobacco. The aerosol-forming substrate may comprise a tobacco-containing material comprising volatile tobacco flavour compounds that are released from the aerosol-forming substrate upon heating. Alternatively, the aerosol-forming substrate may comprise a non-tobacco material. The aerosol-forming substrate may comprise a homogenized plant-derived material. The aerosol-forming substrate may comprise a homogenized tobacco material. The homogenized tobacco material may be formed by agglomerating particulate tobacco. In a particularly preferred embodiment, the aerosol-forming substrate comprises an assembly of crimped sheets of homogenized tobacco material. As used herein, the term "crimped sheet" refers to a sheet having a plurality of substantially parallel ridges or corrugations.

[0062] The aerosol-forming substrate may include at least one aerosol former. The aerosol former is any suitable known compound or mixture of compounds that facilitates the formation of a dense, stable aerosol during use and is substantially resistant to thermal decomposition at the operating temperature of the system. Suitable aerosol formers are known in the art and include, but are not limited to, polyhydric alcohols (such as triethylene glycol, 1,3-butanediol, and glycerin), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, or triacetate), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as dimethyl dodecanedioate and dimethyl tetradecanedioate). A preferred aerosol former is a polyhydric alcohol or mixture thereof (such as triethylene glycol, 1,3-butanediol, and the like). Preferably, the aerosol former is glycerin. When present, the homogenized tobacco material may have an aerosol former content of 5 percent or more on a dry weight basis, and preferably has an aerosol former content of 5 percent to 30 percent by weight on a dry weight basis. The aerosol-forming substrate may contain other additives and ingredients, such as flavourants.

[0063] 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 within 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 completely received within the chamber of the aerosol-generating device.

[0064] The aerosol-generating article may be substantially cylindrical. 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 containing the aerosol-forming substrate. The aerosol-forming segment may be substantially cylindrical. 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.

[0065] The aerosol-generating article may have an overall length of approximately 30 millimeters to approximately 100 millimeters. In one embodiment, the aerosol-generating article may have an overall length of approximately 45 millimeters. The aerosol-generating article may have an outer diameter of approximately 5 millimeters to approximately 12 millimeters. In one embodiment, the aerosol-generating article may have an outer diameter of approximately 7.2 millimeters.

[0066] The aerosol-forming substrate may be provided as an aerosol-forming segment having a length of about 7 millimeters to about 15 millimeters. In one embodiment, the aerosol-forming segment may have a length of approximately 10 millimeters. Alternatively, the aerosol-forming segment may have a length of approximately 12 millimeters.

[0067] The aerosol-generation segment preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article. The outer diameter of the aerosol-forming segment may be between approximately 5 millimeters and approximately 12 millimeters. In one embodiment, the aerosol-forming segment may have an outer diameter of approximately 7.2 millimeters.

[0068] The aerosol-generating article may include a filter plug. The filter plug may be located at a downstream end of the aerosol-generating article. The filter plug may be a cellulose acetate filter plug. In one embodiment, the filter plug is approximately 7 millimeters long, but may have a length of approximately 5 millimeters to approximately 10 millimeters.

[0069] The aerosol-generating article may comprise an outer paper wrapper. Additionally, the aerosol-generating article may comprise a separation between the aerosol-forming substrate and the filter plug. The separation may be approximately 18 millimeters, but may range from approximately 5 millimeters to approximately 25 meters.

[0070] According to a third aspect of the present invention, there is provided an aerosol generation system comprising an aerosol generating device, a susceptor element, and an aerosol-generating article comprising an aerosol-forming substrate. The aerosol generating device comprises a housing and an inductor coil arranged within the housing for receiving at least a portion of the aerosol-generating article within the inductor coil such that the inductor coil contacts the aerosol-generating article when the aerosol-generating article is received within the inductor coil. The susceptor element is configured for placement of at least a portion of the susceptor element within the inductor coil. The aerosol generating device also comprises a power supply and 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 within the inductor coil.

[0071] The aerosol generating device may comprise any of the optional or preferred features described herein in relation to the first aspect of the invention.

[0072] The aerosol-generating article may comprise any of the optional or preferred features described herein in relation to the second aspect of the invention.

[0073] According to a fourth aspect of the present invention there is provided an aerosol generating apparatus comprising a housing for receiving at least a portion of an aerosol-generating article in the inductor coil such that the inductor coil contacts the aerosol-generating article when the aerosol-generating article is received in the inductor coil, and an inductor coil arranged in the housing. The aerosol generating apparatus also comprises a power supply and 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.

[0074] Advantageously, configuring the inductor coil to contact an aerosol-generating article received therein may increase heating of the aerosol-generating article during use. For example, inductor coils typically exhibit a relatively small amount of resistive heating when an alternating current is provided to the inductor coil. Thus, providing contact between the inductor coil and the aerosol-generating article may facilitate conductive heat transfer from the inductor coil to the aerosol-generating article.

[0075] Advantageously, configuring the inductor coil to contact an aerosol-generating article received therein may facilitate retention of the aerosol-generating article within the aerosol generating device during use For example, 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.

[0076] Advantageously, disposing the inductor coil in contact with an aerosol-generating article received within the inductor coil may reduce or minimize the distance between the inductor coil and the susceptor element. Advantageously, disposing the inductor coil in contact with an aerosol-generating article received within the inductor coil eliminates any intervening material between the inductor coil and the aerosol-generating article. Advantageously, one or both of these features may maximize inductive energy transfer from the inductor coil to the susceptor element. This may be particularly advantageous in embodiments in which the susceptor element is positioned inside the aerosol-generating article during use.

[0077] The aerosol generating device may comprise a chamber. The housing may at least partially define the chamber. The chamber preferably includes an open end through which the aerosol-generating article is inserted into the inductor coil. The chamber preferably includes a closed end opposite the open end. In use, the aerosol-generating article is received in the chamber when it is received in the inductor coil.

[0078] Advantageously, the chamber may facilitate assembly of the aerosol generating device, in particular, the chamber may hold the inductor coil in a desired position within the housing.

[0079] An inductor coil may be disposed at least partially within the chamber.

[0080] The aerosol generating device may comprise any of the optional or preferred features described herein in relation to the first aspect of the invention.

[0081] According to a fifth aspect of the invention there is provided an aerosol generating system comprising an aerosol generating device according to the fourth aspect of the invention according to any of the embodiments described herein. The aerosol generating system also comprises an aerosol-generating article having an aerosol-forming substrate and configured for use in the aerosol generating device. The aerosol-generating article may comprise any of the optional or preferred features described herein in relation to the second aspect of the invention.

[0082] The invention will now be further described, by way of example only, with reference to the accompanying drawings in which: [Brief description of the drawings]

[0083] [Figure 1] FIG. 1 shows a perspective view of an aerosol generation system according to a first embodiment of the present invention. [Diagram 2] FIG. 2 shows a perspective view of the aerosol generating system of FIG. 1 with an aerosol-generating article inserted into the aerosol generating device. [Diagram 3] FIG. 3 shows a cross-sectional view of the aerosol generating device of the aerosol generating system of FIG. [Figure 4] FIG. 4 shows a cross-sectional view of the aerosol generation system of FIG. [Diagram 5] FIG. 5 shows a cross-sectional view of an aerosol generating device according to a second embodiment of the present invention. [Figure 6] FIG. 6 shows a cross-sectional view of an aerosol generating device according to a third embodiment of the present invention. [Figure 7] FIG. 7 shows a perspective view of an alternative inductor coil arrangement according to the present invention. [Figure 8] FIG. 8 shows a cross-sectional view of a further alternative inductor coil arrangement in accordance with the present invention. [Figure 9] FIG. 9 illustrates a cross-sectional view of yet a further alternative inductor coil arrangement in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0084] 1 to 4 show an aerosol generating system 10 according to a first embodiment of the present invention. The aerosol generating system 10 comprises an aerosol generating device 12 and an aerosol-generating article 14.

[0085] The aerosol generating device 12 includes a housing 16 defining a chamber 18 for receiving a portion of the aerosol-generating article 14. The chamber 18 includes an open end 20 through which the aerosol-generating article 14 is inserted into the chamber 18, and a closed end 22 opposite the open end 20. A susceptor element 24 extends from the closed end 22 of the chamber 18 for insertion into the aerosol-generating article 14.

[0086] 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.

[0087] The housing 16 , the chamber 18 , the inductor coil 26 , and the susceptor element 24 are arranged concentrically about a central axis 29 of the aerosol generating device 12 .

[0088] The aerosol generating device 12 also includes a controller 30 and a power supply 32 connected to the inductor coil 26. The controller 30 is configured to provide an alternating current from the power supply 32 to the inductor coil 26 to generate an alternating magnetic field, which inductively heats the susceptor element 24.

[0089] The aerosol-generating article 14 comprises an aerosol-forming substrate 34 in the form of a tobacco plug, 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 such 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 in turn heats the aerosol-forming substrate 34 to generate an aerosol. The aerosol-generating device 12 comprises an air inlet 44 extending through the housing 16 and providing fluid communication between the exterior of the aerosol-generating device 12 and the chamber 18 adjacent the closed end 22. During use, a user draws air into mouthpiece 40 of aerosol-generating article 14, drawing an airflow into chamber 18 via air inlet 44. The airflow then flows into aerosol-forming substrate 34, at which point aerosol becomes entrained in the airflow. The airflow and aerosol then flow through hollow acetate tubing 36, polymeric filter 38, and mouthpiece 40 for delivery to the user.

[0090] Figure 5 shows a cross-sectional view of an aerosol generation device 112 according to a second embodiment of the present invention. The aerosol generation device 112 is similar to the aerosol generation device 12 described with reference to Figures 1 to 4, and like reference numerals have been used to designate like parts.

[0091] The aerosol generating device 112 comprises 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 further comprises an annular slot 121 in the inner housing portion 117 and in communication with the chamber 18. The inductor coil 26 is disposed in the slot 121 such that the inductor coil 26 extends partially into the chamber 18. An outer surface of the inductor coil 26 abuts an inner surface of the outer housing portion 119. The aerosol generating device 112 can be combined with the aerosol generating article 14 described with reference to Figures 1 to 4, and the operation of the aerosol generating device 112 is identical to that of the aerosol generating device 12.

[0092] Figure 6 shows a cross-sectional view of an aerosol generation device 212 according to a third embodiment of the present invention. The aerosol generation device 212 is similar to the aerosol generation device 112 described with reference to Figure 5, and like reference numerals have been used to designate like parts.

[0093] The aerosol generating device 212 comprises a housing 216 with an inner housing part 217 that is overmolded over the inductor coil 26 to form a recess 223 in which the inductor coil 26 is disposed such that the inductor coil 26 extends partially into the chamber 18. The outer surface of the inductor coil 26 abuts the portion of the inner housing part 217 that forms the recess 223. The aerosol generating device 112 can be combined with the aerosol-generating article 14 described with reference to Figures 1 to 4, and the operation of the aerosol generating device 112 is identical to that of the aerosol generating device 12.

[0094] FIG 7 illustrates an alternative inductor coil 326 that may be used in any of the aerosol generating devices described with reference to FIGS. 1-6 in place of the inductor coil 26. Each winding 328 of the inductor coil 326 contacts an adjacent winding 328, eliminating gaps between the windings 328. This reduces or prevents contaminants or debris from getting caught between the 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 from a conductive wire that is coated with an electrically insulating outer layer 329.

[0095] FIG. 8 shows a cross-sectional view of a further alternative inductor coil 426. The inductor coil 426 is substantially identical to the inductor coil 326 shown in FIG. 7, except that the inductor coil 426 is formed from a wire having a square cross-sectional shape. The inductor coil 426 defines a lumen 431 extending therethrough for receiving a portion of the aerosol-generating article 14. The windings 428 of the inductor coil 426 have the same diameter such that the cross-sectional area of ​​the lumen 431 remains constant along the central axis 29. The result of this arrangement is an inner surface 433 of the inductor coil 426 that is substantially smooth along the central axis 29.

[0096] Figure 9 shows a cross-sectional view of yet a further alternative inductor coil 526. The inductor coil 526 is similar to the inductor coil 426 described with reference to Figure 8. 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 may facilitate the insertion of an 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 the aerosol-generating article; an inductor coil disposed at least partially within the chamber, the inductor coil being formed from a resilient material such that windings of the inductor coil are biased against an inner surface of the chamber; an aerosol generating device comprising: a power supply and 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, thereby heating at least a portion of an aerosol-generating article received within the inductor coil.

2. 10. The aerosol generating device of claim 1, further comprising an elongated susceptor element disposed at least partially within the inductor coil.

3. 3. The aerosol generating device of claim 1, wherein the inductor coil is configured to receive at least a portion of an aerosol-generating article within the inductor coil and is configured to contact the aerosol-generating article when the aerosol-generating article is received within the inductor coil.

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

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

6. 6. The aerosol generating device of claim 5, wherein the inductor coil is formed from a wire having a conductive core and an outer layer surrounding the conductive core, the outer layer comprising an electrically insulating material.

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

8. 8. The aerosol generating device of claim 7, wherein a plane of each winding of the inductor coil contacts a plane of an adjacent winding of the inductor coil.

9. 9. The aerosol generating device of claim 8, wherein the inductor coil defines a lumen extending therethrough for receiving an aerosol generating article, and wherein the multiple continuous windings of the inductor coil define a first portion of the lumen having a constant cross-sectional area.

10. 10. The aerosol generating device of claim 9, wherein the lumen has a first end, a second end, and a length extending between the first end and the second end, and the lumen has a constant cross-sectional area along its length.

11. 10. The aerosol generating device of claim 9, wherein the inductor coil is disposed within the housing such that an aerosol-generating article inserted into the inductor coil enters the cavity through a first end of the cavity, and a second portion of the cavity extends between the first portion of the cavity and the first end of the cavity, and a cross-sectional area of ​​the second portion increases in a direction from the first portion toward the first end.

12. 12. The aerosol generating device of claim 11, wherein the lumen has a second end opposite the first end, and the first portion of the lumen extends between the second portion of the lumen and the second end.

13. 13. An aerosol generating system comprising an aerosol generating device according to any one of claims 1 to 12, and an aerosol-generating article having an aerosol-forming substrate and configured for use in the aerosol generating device.

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