Patent Description:
Smoking articles such as cigarettes, cigars and the like burn tobacco during use to create tobacco smoke. Attempts have been made to provide alternatives to these articles by creating products that release compounds without combusting. Examples of such products are so-called "heat not burn" products or tobacco heating devices or products, which release compounds by heating, but not burning, material. The material may be, for example, tobacco or other non-tobacco products, which may or may not contain nicotine.

<CIT> discloses an atomization device comprising a casing and a cabin body positioned in the casing. A cabin wall of the cabin body is made of aluminium and defines a cavity in which solid tobacco materials are stored. The device has a coil connected to an alternating power supply. On operation of the coil, the solid tobacco materials are heatable in the cavity by self-heat-generation of the cabin wall. <CIT> discloses an induction heating source for use with an electrical smoking article. A plurality of induction heating sources provide alternating electromagnetic fields, each of which inductively heats a susceptor in thermal proximity with tobacco flavor medium to generate aerosols. <CIT> discloses a cigarette smoking system based on electromagnetic heating.

A first aspect of the present invention provides a system as defined in claim <NUM>.

In an exemplary embodiment, the heating zone is defined by the heating element.

In an exemplary embodiment, the heating zone is free of any heating material that is heatable by penetration with a varying magnetic field.

In an exemplary embodiment, the heating element is a tubular heating element that encircles the heating zone.

In an exemplary embodiment, the apparatus comprises a mass of thermal insulation encircling the heating element.

In an exemplary embodiment, the magnetic field generator comprises a coil and a device for passing a varying electrical current through the coil. The varying electrical current may be an alternating current.

In an exemplary embodiment, the coil encircles the heating element.

In an exemplary embodiment, the apparatus comprises a mass of thermal insulation between the coil and the heating element.

In an exemplary embodiment, the thermal insulation comprises one or more thermal insulators selected from the group consisting of a closed-cell material, a closed-cell plastics material, an aerogel, vacuum insulation, silicone foam, a rubber material, wadding, fleece, non-woven material, non-woven fleece, woven material, knitted material, nylon, foam, polystyrene, polyester, polyester filament, polypropylene, a blend of polyester and polypropylene, cellulose acetate, paper or card, and corrugated material such as corrugated paper or card.

In an exemplary embodiment, the apparatus comprises a mass of thermal insulation encircling the coil.

In an exemplary embodiment, the thermal insulation comprises one or more thermal insulators selected from the group consisting of: a closed-cell material, a closed-cell plastics material, an aerogel, vacuum insulation, silicone foam, a rubber material, wadding, fleece, non-woven material, non-woven fleece, woven material, knitted material, nylon, foam, polystyrene, polyester, polyester filament, polypropylene, a blend of polyester and polypropylene, cellulose acetate, paper or card, and corrugated material such as corrugated paper or card.

In an exemplary embodiment, the apparatus comprises a gap of between about one and about three millimetres between an outermost surface of the heating element and an innermost surface of the coil. In an exemplary embodiment, the gap is between about <NUM> and about <NUM> millimetres.

In an exemplary embodiment, the coil extends along a longitudinal axis that is substantially aligned with a longitudinal axis of the elongate heating element. In an exemplary embodiment, the axes are coincident.

In an exemplary embodiment, an impedance of the coil is equal, or substantially equal, to an impedance of the heating element.

In an exemplary embodiment, an outer surface of the heating element has a thermal emissivity of <NUM> or less. In an exemplary embodiment, the thermal emissivity is <NUM> or less.

In an exemplary embodiment, the heating element comprises an elongate heating member extending at least partially around the heating zone and consisting entirely, or substantially entirely, of the heating material.

In respective exemplary embodiments, the heating material comprises one or more materials selected from the group consisting of: an electrically-conductive material, a magnetic material, and a non-magnetic material. In respective exemplary embodiments, the heating material comprises a metal or a metal alloy. In respective exemplary embodiments, the heating material comprises one or more materials selected from the group consisting of: aluminium, gold, iron, nickel, cobalt, conductive carbon, graphite, plain-carbon steel, stainless steel, ferritic stainless steel, copper, and bronze.

In an exemplary embodiment, the heating material is susceptible to eddy currents being induced in the heating material when penetrated by the varying magnetic field.

In an exemplary embodiment, a first portion of the heating element is more susceptible to eddy currents being induced therein by penetration with the varying magnetic field than a second portion of the heating element.

In an exemplary embodiment, the heating element comprises an elongate heating member comprising the heating material, and a coating on an inner surface of the heating member, wherein the coating is smoother or harder than the inner surface of the heating member. The coating may comprise glass or a ceramic material.

In an exemplary embodiment, the apparatus comprises a temperature sensor for sensing a temperature of the heating zone or of the heating element. In an exemplary embodiment, the magnetic field generator is arranged to operate on the basis of an output of the temperature sensor.

In an exemplary embodiment, the apparatus comprises:.

In an exemplary embodiment, the mouthpiece comprises the heating zone.

In an exemplary embodiment, the body comprises the heating zone.

As used herein, the term "smokable material" includes materials that provide volatilised components upon heating, typically in the form of vapour or an aerosol. "Smokable material" may be a non-tobacco-containing material or a tobacco-containing material. "Smokable material" may, for example, include one or more of tobacco per se, tobacco derivatives, expanded tobacco, reconstituted tobacco, tobacco extract, homogenised tobacco or tobacco substitutes. The smokable material can be in the form of ground tobacco, cut rag tobacco, extruded tobacco, liquid, gel, gelled sheet, powder, or agglomerates. "Smokable material" also may include other, non-tobacco, products, which, depending on the product, may or may not contain nicotine. "Smokable material" may comprise one or more humectants, such as glycerol or propylene glycol.

As used herein, the term "heating material" refers to material that is heatable by penetration with a varying magnetic field.

As used herein, the terms "flavour" and "flavourant" refer to materials which, where local regulations permit, may be used to create a desired taste or aroma in a product for adult consumers. They may include extracts (e.g., liquorice, hydrangea, Japanese white bark magnolia leaf, chamomile, fenugreek, clove, menthol, Japanese mint, aniseed, cinnamon, herb, wintergreen, cherry, berry, peach, apple, Drambuie, bourbon, scotch, whiskey, spearmint, peppermint, lavender, cardamom, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium, honey essence, rose oil, vanilla, lemon oil, orange oil, cassia, caraway, cognac, jasmine, ylang-ylang, sage, fennel, piment, ginger, anise, coriander, coffee, or a mint oil from any species of the genus Mentha), flavour enhancers, bitterness receptor site blockers, sensorial receptor site activators or stimulators, sugars and/or sugar substitutes (e.g., sucralose, acesulfame potassium, aspartame, saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol), and other additives such as charcoal, chlorophyll, minerals, botanicals, or breath freshening agents. They may be imitation, synthetic or natural ingredients or blends thereof. They may be in any suitable form, for example, oil, liquid, gel, powder, or the like.

Induction heating is a process in which an electrically-conductive object is heated by penetrating the object with a varying magnetic field. The process is described by Faraday's law of induction and Ohm's law. An induction heater may comprise an electromagnet and a device for passing a varying electrical current, such as an alternating current, through the electromagnet. When the electromagnet and the object to be heated are suitably relatively positioned so that the resultant varying magnetic field produced by the electromagnet penetrates the object, one or more eddy currents are generated inside the object. The object has a resistance to the flow of electrical currents. Therefore, when such eddy currents are generated in the object, their flow against the electrical resistance of the object causes the object to be heated. This process is called Joule, ohmic, or resistive heating. An object that is capable of being inductively heated is known as a susceptor.

It has been found that, when the susceptor is in the form of a closed circuit, magnetic coupling between the susceptor and the electromagnet in use is enhanced, which results in greater or improved Joule heating.

Magnetic hysteresis heating is a process in which an object made of magnetic material is heated by penetrating the object with a varying magnetic field. A magnetic material can be considered to comprise many atomic-scale magnets, or magnetic dipoles. When a magnetic field penetrates such material, the magnetic dipoles align with the magnetic field. Therefore, when a varying magnetic field, such as an alternating magnetic field, for example as produced by an electromagnet, penetrates the magnetic material, the orientation of the magnetic dipoles changes with the varying applied magnetic field. Such magnetic dipole reorientation causes heat to be generated in the magnetic material.

When an object is both electrically-conductive and magnetic, penetrating the object with a varying magnetic field can cause both Joule heating and magnetic hysteresis heating in the object. Moreover, the use of magnetic material can strengthen the magnetic field, which can intensify the Joule heating.

In each of the above processes, as heat is generated inside the object itself, rather than by an external heat source by heat conduction, a rapid temperature rise in the object and more uniform heat distribution can be achieved, particularly through selection of suitable object material and geometry, and suitable varying magnetic field magnitude and orientation relative to the object. Moreover, as induction heating and magnetic hysteresis heating do not require a physical connection to be provided between the source of the varying magnetic field and the object, design freedom and control over the heating profile may be greater, and cost may be lower.

Referring to <FIG> there are respectively shown a schematic cross-sectional view of an example of apparatus for heating smokable material to volatilise at least one component of the smokable material, according to an embodiment of the invention, and a schematic perspective view of a portion of the apparatus. Broadly speaking, the apparatus <NUM> comprises a heater or heating zone <NUM> for receiving at least a portion of an article comprising smokable material, a magnetic field generator <NUM> for generating a varying magnetic field, and an elongate heating element <NUM> extending around the heating zone <NUM> and comprising heater material or heating material that is heatable by penetration with the varying magnetic field to heat the heating zone <NUM>.

In this embodiment, the heating element <NUM> is a tubular heating element <NUM> that encircles the heating zone <NUM>. In this embodiment, the heating zone <NUM> comprises a cavity. However, in other embodiments, the heating element <NUM> may not be fully tubular. For example, in some embodiments, the heater or heating element <NUM> may be tubular save for an axially-extending gap or slit formed in the heating element <NUM>. In this embodiment, the heating element <NUM> has a substantially circular cross section. However, in other embodiments, the heating element may have a cross section other than circular, such as square, rectangular, polygonal or elliptical.

In this embodiment, the heating zone <NUM> is defined by the heating element <NUM>. That is, the heating element <NUM> delineates or delimits the heating zone <NUM>. Moreover, in this embodiment, the heating zone <NUM> itself is free of any heating material that is heatable by penetration with a varying magnetic field. Thus, when a varying magnetic field is generated by the magnetic field generator <NUM> as discussed below, more energy of the varying magnetic field is available to cause heating of the heating element <NUM>. In other embodiments, there may be a further heating element comprising heating material in the heating zone <NUM>.

The heating element <NUM> of this embodiment comprises an elongate tubular heating member <NUM> extending around the heating zone <NUM> and consisting entirely, or substantially entirely, of the heating material. The heating member <NUM> thus comprises a closed circuit of heating material that is heatable by penetration with a varying magnetic field. Moreover, in this embodiment, the heating element <NUM> comprises a coating <NUM> on an inner surface of the heating member <NUM>. The coating <NUM> is smoother or harder than the inner surface of the heating member <NUM> itself. Such a smoother or harder coating <NUM> may facilitate cleaning of the heating element <NUM> after use of the apparatus <NUM>. The coating <NUM> could be made of glass or a ceramic material, for example. In other embodiments, the coating <NUM> may be omitted. In some embodiments, the coating may be rougher than the outer surface of the heating member <NUM> itself, so as to increase the surface area over which the heating element <NUM> is contactable with an article or smokable material inserted in the heating zone <NUM> in use.

The heating material may comprise one or more materials selected from the group consisting of: an electrically-conductive material, a magnetic material, and a non-magnetic material. The heating material may comprise a metal or a metal alloy. The heating material may comprise one or more materials selected from the group consisting of: aluminium, gold, iron, nickel, cobalt, conductive carbon, graphite, plain-carbon steel, stainless steel, ferritic stainless steel, copper, and bronze. Other material(s) may be used as the heating material in other embodiments. In this embodiment, the heating material of the heating element <NUM> comprises electrically-conductive material. Thus, the heating material is susceptible to eddy currents being induced in the heating material when penetrated by a varying magnetic field. Therefore, the heating element <NUM> is able to act as a susceptor when subjected to the changing magnetic field. It has also been found that, when magnetic electrically-conductive material is used as the heating material, magnetic coupling between the heating element <NUM> and the coil <NUM> of the magnetic field generator <NUM>, which will be described below, in use may be enhanced. In addition to potentially enabling magnetic hysteresis heating, this can result in greater or improved Joule heating of the heating element <NUM>, and thus greater or improved heating of the heating zone <NUM>.

The heating element <NUM> preferably has a small thickness as compared to the other dimensions of the heating element <NUM>. A susceptor may have a skin depth, which is an exterior zone within which most of an induced electrical current occurs. By providing that the heating element <NUM> has a relatively small thickness, a greater proportion of the heating element <NUM> may be heatable by a given varying magnetic field, as compared to a heating element <NUM> having a depth or thickness that is relatively large as compared to the other dimensions of the heating element <NUM>. Thus, a more efficient use of material is achieved. In turn, costs are reduced.

In some embodiments, a first portion of the heating element <NUM> is more susceptible to eddy currents being induced therein by penetration with the varying magnetic field than a second portion of the heating element <NUM>. For example, in some embodiments, the heating element <NUM> in the apparatus <NUM> of <FIG> may be replaced by the heating element <NUM> shown in <FIG>.

In the heating element <NUM> of <FIG>, a first portion <NUM> of the heating element <NUM> is more susceptible to eddy currents being induced therein by penetration with a varying magnetic field than a second portion <NUM> of the heating element <NUM>. The first portion <NUM> of the heating element <NUM> may have the higher susceptibility as a result of the first portion <NUM> of the heating element <NUM> being made of a first material, the second portion <NUM> of the heating element <NUM> being made of a different second material, and the first material being of a higher susceptibility than the second material. For example, one of the first and second portions <NUM>, <NUM> may be made of iron, and the other of the first and second portions <NUM>, <NUM> may be made of graphite. Alternatively or additionally, the first portion <NUM> of the heating element <NUM> may have the higher susceptibility as a result of the first portion <NUM> of the heating element <NUM> having a different thickness and/or material density to the second portion <NUM> of the heating element <NUM>.

The higher susceptibility portion <NUM> may be located closer to an intended mouth end of the apparatus <NUM>, or the lower susceptibility portion <NUM> may be located closer to the intended mouth end of the apparatus <NUM>. In the latter scenario, the lower susceptibility portion <NUM> may heat smokable material in an article located in the heating zone <NUM> to a lesser degree than the higher susceptibility portion <NUM>, and thus the lesser heated smokable material could act as a filter, to reduce the temperature of created vapour or make the vapour created in the article mild during heating of the smokable material.

While in <FIG> the first and second portions <NUM>, <NUM> are located adjacent each other in the longitudinal direction of the heating element <NUM>, in other embodiments this need not be the case. For example, in some embodiments the first and second portions <NUM>, <NUM> may be disposed adjacent each other in a direction perpendicular to the longitudinal direction of the heating element <NUM>.

Such varying susceptibility of the heating element <NUM> to eddy currents being induced therein can help achieve progressive heating of smokable material in an article inserted in the heating zone <NUM>, and thereby progressive generation of vapour. For example, the higher susceptibility portion <NUM> may be able to heat a first region of the smokable material relatively quickly to initialise volatilisation of at least one component of the smokable material and formation of a vapour in the first region of the smokable material. The lower susceptibility portion <NUM> may be able to heat a second region of the smokable material relatively slowly to initialise volatilisation of at least one component of the smokable material and formation of a vapour in the second region of the smokable material. Accordingly, a vapour is able to be formed relatively rapidly for inhalation by a user, and vapour can continue to be formed thereafter for subsequent inhalation by the user even after the first region of the smokable material may have ceased generating vapour. The first region of the smokable material may cease generating the vapour when it becomes exhausted of volatilisable components of the smokable material.

In other embodiments, all of the heating element <NUM> may be equally, or substantially equally, susceptible to eddy currents being induced therein by penetration with a varying magnetic field. In some embodiments, the heating element <NUM> may not be susceptible to such eddy currents. In such embodiments, the heating material may be a magnetic material that is non-electrically-conductive, and thus may be heatable by the magnetic hysteresis process discussed above.

In some embodiments, the apparatus may comprise a catalytic material on at least a portion of an inner surface 110a of the heating element <NUM>. The catalytic material may be provided on all of the inner surface 110a of the heating element <NUM>, or on only some portion(s) of the inner surface 110a of the heating element <NUM>. The catalytic material may take the form of a coating. The provision of such a catalytic material means that, in use, the apparatus <NUM> may have a heated, chemically active surface. In use, the catalytic material may act to convert, or increase the rate of conversion of, a potential irritant to something that is less of an irritant. In use, the catalytic material may act to convert, or increase the rate of conversion of, formic acid to methanol, for example. In other embodiments, the catalytic material may act to convert, or increase the rate of conversion of, other chemicals, such as acetylene to ethane by hydrogenation, or ammonia to nitrogen and hydrogen. The catalytic material may additionally or alternatively act to react, or increase the rate of reaction of, carbon monoxide and water vapour to form carbon dioxide and hydrogen (the water-gas shift reaction, or WGSR).

In some embodiments, an outer surface 110b of the heating element <NUM> may have a thermal emissivity of <NUM> or less. For example, in some embodiments, the outer surface 110b of the heating element <NUM> may have a thermal emissivity of <NUM> or less, such as <NUM> or <NUM>. Such low emissivity helps to retain heat in the heating element <NUM> and in the heating zone <NUM> and provide some or all of the other thermal benefits of the thermal insulation discussed below. The thermal emissivity may be achieved by making the outer surface 110b of the heating element <NUM> from a low emissivity material, such as silver or aluminium.

The magnetic field generator <NUM> of this embodiment comprises an electrical power source <NUM>, the coil <NUM>, a device <NUM> for passing a varying electrical current, such as an alternating current, through the coil <NUM>, a controller <NUM>, and a user interface <NUM> for user-operation of the controller <NUM>.

In this embodiment, the electrical power source <NUM> is a rechargeable battery. In other embodiments, the electrical power source <NUM> may be other than a rechargeable battery, such as a non-rechargeable battery, a capacitor or a connection to a mains electricity supply.

The coil <NUM> may take any suitable form. In this embodiment, the coil <NUM> is a helical coil of electrically-conductive material, such as copper. In some embodiments, the magnetic field generator <NUM> may comprise a magnetically permeable core around which the coil <NUM> is wound. Such a magnetically permeable core concentrates the magnetic flux produced by the coil <NUM> in use and makes a more powerful magnetic field. The magnetically permeable core may be made of iron, for example. In some embodiments, the magnetically permeable core may extend only partially along the length of the coil <NUM>, so as to concentrate the magnetic flux only in certain regions.

In this embodiment, the coil <NUM> is a circular helix. That is, the coil <NUM> has a substantially constant radius along its length. In other embodiments, the radius of the coil <NUM> may vary along its length. For example, in some embodiments, the coil <NUM> may comprise a conic helix or an elliptical helix. In this embodiment, the coil <NUM> has a substantially constant pitch along its length. That is, a width measured parallel to the longitudinal axis of the coil <NUM> of a gap between any two adjacent turns of the coil <NUM> is substantially the same as a width of a gap between any other two adjacent turns of the coil <NUM>. In other embodiments, this may not be true. The provision of a varying pitch may enable the strength of a varying magnetic field produced by the coil <NUM> to be different at different portions of the coil <NUM>, which may help provide progressive heating of the heating element <NUM> and heating zone <NUM>, and thus any article located in the heating zone <NUM>, in a manner similar to that described above.

In this embodiment, the coil <NUM> is in a fixed position relative to the heating element <NUM> and the heating zone <NUM>. In this embodiment, the coil <NUM> encircles the heating element <NUM> and the heating zone <NUM>. In this embodiment, the coil <NUM> extends along a longitudinal axis that is substantially aligned with a longitudinal axis A-A of the heating zone <NUM>. In this embodiment, the aligned axes are coincident. In a variation to this embodiment, the aligned axes may be parallel to each other. However, in other embodiments, the axes may be oblique to each other. Moreover, in this embodiment, the coil <NUM> extends along a longitudinal axis that is substantially coincident with a longitudinal axis of the heating element <NUM>. This can help to provide more uniform heating of the heating element <NUM> in use, and can also aid manufacturability of the apparatus <NUM>. In other embodiments, the longitudinal axes of the coil <NUM> and the heating element <NUM> may be aligned with each other by being parallel to each other, or may be oblique to each other.

An impedance of the coil <NUM> of the magnetic field generator <NUM> of this embodiment is equal, or substantially equal, to an impedance of the heating element <NUM>. If the impedance of the heating element <NUM> were instead lower than the impedance of the coil <NUM> of the magnetic field generator <NUM>, then the voltage generated across the heating element <NUM> in use may be lower than the voltage that may be generated across the heating element <NUM> when the impedances are matched. Alternatively, if the impedance of the heating element <NUM> were instead higher than the impedance of the coil <NUM> of the magnetic field generator <NUM>, then the electrical current generated in the heating element <NUM> in use may be lower than the current that may be generated in the heating element <NUM> when the impedances are matched. Matching the impedances may help to balance the voltage and current to maximise the heating power generated at the heating element <NUM> when heated in use. In some other embodiments, the impedances may not be matched.

In this embodiment, the device <NUM> for passing a varying current through the coil <NUM> is electrically connected between the electrical power source <NUM> and the coil <NUM>. In this embodiment, the controller <NUM> also is electrically connected to the electrical power source <NUM>, and is communicatively connected to the device <NUM>. The controller <NUM> is for causing and controlling heating of the heating element <NUM>. More specifically, in this embodiment, the controller <NUM> is for controlling the device <NUM>, so as to control the supply of electrical power from the electrical power source <NUM> to the coil <NUM>. In this embodiment, the controller <NUM> comprises an integrated circuit (IC), such as an IC on a printed circuit board (PCB). In other embodiments, the controller <NUM> may take a different form. In some embodiments, the apparatus may have a single electrical or electronic component comprising the device <NUM> and the controller <NUM>. The controller <NUM> is operated in this embodiment by user-operation of the user interface <NUM>. The user interface <NUM> is located at the exterior of the apparatus <NUM>. The user interface <NUM> may comprise a push-button, a toggle switch, a dial, a touchscreen, or the like.

In this embodiment, operation of the user interface <NUM> by a user causes the controller <NUM> to cause the device <NUM> to cause an alternating electrical current to pass through the coil <NUM>, so as to cause the coil <NUM> to generate an alternating magnetic field. The coil <NUM> and the heating element <NUM> are suitably relatively positioned so that the alternating magnetic field produced by the coil <NUM> penetrates the heating material of the heating element <NUM>. When the heating material of the heating element <NUM> is an electrically-conductive material, this may cause the generation of one or more eddy currents in the heating material. The flow of eddy currents in the heating material against the electrical resistance of the heating material causes the heating material to be heated by Joule heating. As mentioned above, when the heating material is made of a magnetic material, the orientation of magnetic dipoles in the heating material changes with the changing applied magnetic field, which causes heat to be generated in the heating material.

The apparatus <NUM> of this embodiment comprises a temperature sensor <NUM> for sensing a temperature of the heating zone <NUM>. The temperature sensor <NUM> is communicatively connected to the controller <NUM>, so that the controller <NUM> is able to monitor the temperature of the heating zone <NUM>. In some embodiments, the temperature sensor <NUM> may be arranged to take an optical temperature measurement of the heating zone <NUM> or an article located in the heating zone <NUM>. In some embodiments, the article to be located in the heating zone <NUM> may comprise a temperature detector, such as a resistance temperature detector (RTD), for detecting a temperature of the article. The article may further comprise one or more terminals connected, such as electrically-connected, to the temperature detector. The terminal(s) may be for making connection, such as electrical connection, with a temperature monitor (not shown) of the apparatus <NUM> when the article is in the heating zone <NUM>. The controller <NUM> may comprise the temperature monitor. The temperature monitor of the apparatus <NUM> may thus be able to determine a temperature of the article during use of the article with the apparatus <NUM>.

On the basis of one or more signals received from the temperature sensor <NUM> (and/or temperature detector, when provided), the controller <NUM> may cause the device <NUM> to adjust a characteristic of the varying or alternating electrical current passed through the coil <NUM> as necessary, in order to ensure that the temperature of the heating zone <NUM> remains within a predetermined temperature range. The characteristic may be, for example, amplitude or frequency. Within the predetermined temperature range, in use smokable material within an article located in the heating zone <NUM> is heated sufficiently to volatilise at least one component of the smokable material without combusting the smokable material. Accordingly, the controller <NUM>, and the apparatus <NUM> as a whole, is arranged to heat the smokable material to volatilise the at least one component of the smokable material without combusting the smokable material. In some embodiments, the temperature range is about <NUM> to about <NUM>, such as between about <NUM> and about <NUM>, between about <NUM> and about <NUM>, between about <NUM> and about <NUM>, between about <NUM> and about <NUM>, or between about <NUM> and about <NUM>. In some embodiments, the temperature range is between about <NUM> and about <NUM>. In other embodiments, the temperature range may be other than these ranges.

In some embodiments, the apparatus <NUM> may comprises a mouthpiece (not shown). The mouthpiece may be releasably engageable with the rest of the apparatus <NUM> so as to connect the mouthpiece to the rest of the apparatus <NUM>. In other embodiments, the mouthpiece and the rest of the apparatus <NUM> may be permanently connected, such as through a hinge or flexible member.

The mouthpiece may be locatable relative to the heating element <NUM> so as to cover an opening into the heating zone <NUM> through which the article is insertable into the heating zone <NUM>. When the mouthpiece is so located relative to the heating element <NUM>, a channel through the mouthpiece may be in fluid communication with the heating zone <NUM>. In use, the channel acts as a passageway for permitting volatilised material to pass from the heating zone <NUM> to an exterior of the apparatus <NUM>.

As the heating zone <NUM>, and thus any article therein, is being heated, a user may be able to inhale the volatilised component(s) of the smokable material by drawing the volatilised component(s) through a mouthpiece of the article (when provided) or through a mouthpiece of the apparatus <NUM> (when provided). Air may enter the article via a gap between the article and the heating element <NUM>, or in some embodiments the apparatus <NUM> may define an air inlet that fluidly connects the heating zone <NUM> with the exterior of the apparatus <NUM>. As the volatilised component(s) are removed from the article, air may be drawn into the heating zone <NUM> via the air inlet of the apparatus <NUM>.

In this embodiment, the apparatus <NUM> comprises a first mass of thermal insulation <NUM> between the coil <NUM> and the heating element <NUM>. The first mass of thermal insulation <NUM> encircles the heating element <NUM>. In this embodiment, the first mass of thermal insulation <NUM> comprises a closed-cell plastics material. However, in other embodiments, the first mass of thermal insulation <NUM> may comprise, for example, one or more thermal insulators selected from the group consisting of: a closed-cell material, a closed-cell plastics material, an aerogel, vacuum insulation, silicone foam, a rubber material, wadding, fleece, non-woven material, non-woven fleece, woven material, knitted material, nylon, foam, polystyrene, polyester, polyester filament, polypropylene, a blend of polyester and polypropylene, cellulose acetate, paper or card, and corrugated material such as corrugated paper or card. The thermal insulation may additionally or alternatively comprise an air gap. Such a first mass of thermal insulation <NUM> may help to prevent heat loss from the heating element <NUM> to components of the apparatus <NUM> other than the heating zone <NUM>, may help to increase heating efficiency of the heating zone <NUM>, and/or may help to reduce the transfer of heating energy from the heating element <NUM> to an outer surface of the apparatus <NUM>. This may improve the comfortableness with which a user is able to hold the apparatus <NUM>.

In this embodiment, the apparatus <NUM> also comprises a second mass of thermal insulation <NUM> that encircles the coil <NUM>. In this embodiment, the second mass of thermal insulation <NUM> comprises wadding or fleece. However, in other embodiments, the second mass of thermal insulation <NUM> may comprise, for example, one or more materials selected from the group consisting of: aerogel, vacuum insulation, wadding, fleece, non-woven material, non-woven fleece, woven material, knitted material, nylon, foam, polystyrene, polyester, polyester filament, polypropylene, a blend of polyester and polypropylene, cellulose acetate, paper or card, corrugated material such as corrugated paper or card, a closed-cell material, a closed-cell plastics material, an aerogel, vacuum insulation, silicone foam, a rubber material. In some embodiments, the second mass of thermal insulation <NUM> may comprise one or more of the materials discussed above for the first mass of thermal insulation <NUM>. The thermal insulation may additionally or alternatively comprise an air gap. Such a second mass of thermal insulation <NUM> may help to reduce the transfer of heating energy from the heating element <NUM> to an outer surface of the apparatus <NUM>, and may additionally or alternatively help to increase heating efficiency of the heating zone <NUM>.

In some embodiments, one or both of the first and second masses of thermal insulation <NUM>, <NUM> may be omitted. In some embodiments, the coil <NUM> may be embedded in a body of thermal insulation. Such a body of thermal insulation may abut or envelop the heating element <NUM>. The body of thermal insulation could, for example, occupy the spaces occupied by the first and second masses of thermal insulation <NUM>, <NUM> in the apparatus <NUM> of <FIG>, in addition to enveloping the coil <NUM>. Such a body of thermal insulation may comprise, for example, one or more thermal insulators selected from the group consisting of: a closed-cell material, a closed-cell plastics material, an aerogel, vacuum insulation, silicone foam, and a rubber material. In addition to the thermal benefits discussed above, such a body of thermal insulation may help to increase the robustness of the apparatus <NUM>, such as by helping to maintain the relative positioning of the coil <NUM> and the heating element <NUM>. The body of thermal insulation may be manufactured by pouring the material of the body of thermal insulation around the coil <NUM> and against or around the heating element <NUM>, to provide a potted coil <NUM> and heating element <NUM>.

In some embodiments, the apparatus <NUM> comprises a gap between an outermost surface 110b of the heating element <NUM> and an innermost surface of the coil <NUM>. In some such embodiments, the first mass of thermal insulation <NUM> may be omitted. An example such embodiment is shown in <FIG>. Referring to <FIG>, there is shown a schematic cross-sectional view of an example of another apparatus for heating smokable material to volatilise at least one component of the smokable material, according to an embodiment of the invention. The apparatus <NUM> of this embodiment is identical to the apparatus <NUM> of <FIG> except for the omission of the first mass of thermal insulation <NUM>. Any of the above-described possible variations to the apparatus of <FIG> may be made to the apparatus <NUM> of <FIG> to form separate respective embodiments.

Although the dimensions in <FIG> are accentuated for clarity, the apparatus <NUM> comprises a gap G of about two millimetres between an outermost surface 110b of the heating element <NUM> and an innermost surface of the coil <NUM>. In a variation to this embodiment, the gap G may be of other than two millimetres, such as between about one and about three millimetres or between about <NUM> and about <NUM> millimetres. Such a gap G can, in itself, act as a thermal insulator to help provide some or all of the thermal benefits discussed above. In an embodiment such as that shown in <FIG>, the heating element <NUM> may be suspended in the coil <NUM>. The heating element <NUM> may be supported through attachment to the wall to which the temperature sensor <NUM> is mounted.

Some embodiments of the apparatus <NUM> may be arranged to provide "self-cleaning" of the heating element <NUM>. For example, in some embodiments, the controller <NUM> may be arranged, such as on suitable user operation of the user interface <NUM>, to cause the device <NUM> to adjust a characteristic of the varying or alternating electrical current passed through the coil <NUM> as necessary, in order to increase the temperature of the heating element <NUM> to a level at which residue or leftovers on the heating element <NUM> from a previously expended article may be incinerated. The characteristic may be, for example, amplitude or frequency. The temperature may be, for example, in excess of <NUM> degrees Celsius.

Some embodiments of the apparatus <NUM> may be arranged to provide haptic feedback to a user. The feedback could indicate that heating is taking place, or be triggered by a timer to indicate that greater than a predetermined proportion of the original quantity of volatilisable component(s) of the smokable material in an article in the heating zone <NUM> has/have been spent, or the like. The haptic feedback could be created by interaction of the coil <NUM> and the heating element <NUM> (i.e. magnetic response), by interaction of an electrically-conductive element with the coil <NUM>, by rotating an unbalanced motor, by repeatedly applying and removing a current across a piezoelectric element, or the like. Additionally or alternatively, some embodiments of the apparatus <NUM> may utilise such haptics to aid the "self-cleaning" process discussed above, by vibration cleaning the heating element <NUM>.

The magnetic field generator <NUM> is for generating a plurality of varying magnetic fields for penetrating different respective portions of the heating element <NUM>. For example, the apparatus <NUM> may comprise more than one coil. The plurality of coils of the apparatus <NUM> could be operable to provide progressive heating of the heating element <NUM>, and thus progressive heating of smokable material in an article located in the heating zone <NUM>, so as to provide progressive generation of vapour. For example, one coil may be able to heat a first region of the heating material relatively quickly to initialise volatilisation of at least one component of the smokable material and formation of a vapour in a first region of the smokable material. Another coil may be able to heat a second region of the heating material relatively slowly to initialise volatilisation of at least one component of the smokable material and formation of a vapour in a second region of the smokable material. Accordingly, a vapour is able to be formed relatively rapidly for inhalation by a user, and vapour can continue to be formed thereafter for subsequent inhalation by the user even after the first region of the smokable material may have ceased generating vapour. The initially-unheated second region of smokable material could act as a filter, to reduce the temperature of created vapour or make the created vapour mild, during heating of the first region of smokable material.

Referring to <FIG>, there are shown a schematic cross-sectional view of an example of another apparatus for heating smokable material to volatilise at least one component of the smokable material, according to an embodiment of the invention, and a schematic cross-sectional view of a mouthpiece of the apparatus. The apparatus <NUM> of this embodiment is identical to the apparatus <NUM> of <FIG> except for the provision of a mouthpiece <NUM>, and the provision that the mouthpiece <NUM> comprises the heating element <NUM> and the heating zone <NUM>. Any of the above-described possible variations to the apparatus <NUM> of <FIG> may be made to the apparatus <NUM> of <FIG> to form separate respective embodiments.

The apparatus <NUM> of this embodiment comprises a body <NUM> and a mouthpiece <NUM>. The body <NUM> comprises the magnetic field generator <NUM>. The body <NUM> is the same as the apparatus <NUM> shown in <FIG>, except that the heating element <NUM>, and the heating zone <NUM> therein, is instead comprised in the mouthpiece <NUM> and is removable from within the first mass of thermal material <NUM> on movement of the mouthpiece <NUM> relative to the body <NUM>, as shown in <FIG>.

In the position relative to the mouthpiece <NUM> as shown in <FIG>, the body <NUM> of the apparatus <NUM> covers an opening into the heating zone <NUM> through which an article is insertable into the heating zone <NUM>. When the mouthpiece <NUM> is so located relative to the body <NUM>, a passageway <NUM> defined by the mouthpiece <NUM> is in fluid communication with the heating zone <NUM> and places the heating zone <NUM> in fluid communication with the exterior of the apparatus <NUM>. In use of the apparatus <NUM>, the passageway <NUM> permits volatilised material to pass from the heating zone <NUM> to the exterior of the apparatus <NUM>.

The mouthpiece <NUM> is movable relative to the body <NUM> to permit access to the heating zone <NUM> from an exterior of the apparatus <NUM>, such as for insertion or removal of an article or for cleaning the heating zone <NUM>. The provision of the mouthpiece <NUM> may create a through bore through the heating zone <NUM>, which permits cleaning along the full length of the heating zone <NUM>. In this embodiment, the mouthpiece <NUM> is releasably engageable with the body <NUM> so as to connect the mouthpiece <NUM> to the body <NUM>. Thus, the mouthpiece <NUM> may be fully detachable from the body <NUM>, as shown in <FIG>. In some embodiments, the mouthpiece <NUM> may be disposable with the heating element <NUM>. In other embodiments, the mouthpiece <NUM> and the body <NUM> may be permanently connected, such as through a hinge or flexible member. The mouthpiece <NUM> is movable relative to the body <NUM> from the position shown in <FIG> to the position shown in <FIG>, so as to cause the coil <NUM> to encircle the heating element <NUM>.

The mouthpiece <NUM> of the apparatus <NUM> may comprise or be impregnated with a flavourant. The flavourant may be arranged so as to be picked up by hot vapour as the vapour passes through the passageway <NUM> of the mouthpiece <NUM> in use.

In other embodiments of the apparatus <NUM>, the heating element comprised by the mouthpiece may take a different form. For example, the heating element could comprises a rod or strip comprising heating material that is heatable by penetration with the varying magnetic field to heat the heating zone <NUM>. The heating element may be for insertion into an article comprising smokable material and received in the heating zone <NUM>, for example. The heating zone <NUM> may be comprised in the body <NUM> of the apparatus <NUM>, or in the mouthpiece <NUM>. For example, in some embodiments, the heating element is inserted into the heating zone <NUM> as the mouthpiece <NUM> is moved relative to the body <NUM> of the apparatus <NUM>. In other embodiments, the mouthpiece <NUM> comprises one or more components that together define the heating zone <NUM> and the heating element is located in the heating zone <NUM>.

In some embodiments, the apparatus may have a mechanism for compressing the article when the article is inserted in the recess or cooperating with the interface. Such compression of the article can compress the smokable material in the article, so as to increase the thermal conductivity of the smokable material. In other words, compression of the smokable material can provide for higher heat transfer through the article. For example, in some embodiments, the apparatus may comprise first and second members between which the heating zone <NUM> is located. The first and second members may be movable towards each other to compress the heating zone <NUM>. In some embodiments, the first and second members may be free of any heating material. Thus, when a varying magnetic field is generated by the magnetic field generator <NUM>, more energy of the varying magnetic field is available to cause heating of the heating element <NUM>. However, in other embodiments, one or both of the first and second members may comprise heating material that is heatable by penetration with the varying magnetic field generated by the magnetic field generator <NUM>. This may provide further and/or more uniform heating of the smokable material of the article.

In some embodiments, the heating material of the heating element <NUM> may comprise discontinuities or holes therein. Such discontinuities or holes may act as thermal breaks to control the degree to which different regions of the smokable material are heated in use. Areas of the heating material with discontinuities or holes therein may be heated to a lesser extent that areas without discontinuities or holes. This may help progressive heating of the smokable material, and thus progressive generation of vapour, to be achieved.

In each of the above described embodiments, the smokable material comprises tobacco. However, in respective variations to each of these embodiments, the smokable material may consist of tobacco, may consist substantially entirely of tobacco, may comprise tobacco and smokable material other than tobacco, may comprise smokable material other than tobacco, or may be free of tobacco. In some embodiments, the smokable material may comprise a vapour or an aerosol forming agent or a humectant, such as glycerol, propylene glycol, triactein, or diethylene glycol.

In some embodiments, the article discussed above is sold, supplied or otherwise provided separately from the apparatus <NUM>, <NUM>, <NUM> with which it is usable. However, in some embodiments, the apparatus <NUM>, <NUM>, <NUM> and one or more of the articles may be provided together as a system, such as a kit or an assembly, possibly with additional components, such as cleaning utensils.

The invention could be implemented in a system comprising any one of the articles discussed herein, and any one of the apparatuses discussed herein, wherein the article itself further has heating material, such as in a susceptor, for heating by penetration with the varying magnetic field generated by the magnetic field generator. Heat generated in the heating material of the article itself could be transferred to the smokable material to further heat the smokable material therein.

Claim 1:
A system comprising:
an apparatus (<NUM>, <NUM>, <NUM>) configured to heat smokable material to volatilize at least one component of the smokable material, the apparatus comprising:
a heating zone (<NUM>) configured to receive at least a portion of an article including smokable material;
a magnetic field generator (<NUM>) configured to generate a plurality of varying magnetic fields; and
an elongate heating element (<NUM>) disposed at least partially around the heating zone (<NUM>) and including heating material that is heatable by penetration with the varying magnetic field to thereby heat the heating zone (<NUM>);
wherein the magnetic field generator is for generating the plurality of varying magnetic fields for penetrating different respective portions of the heating element (<NUM>); and characterised in that the system further comprises:
the article for use with the apparatus, the article comprising the smokable material.