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 that burn tobacco by creating products that release compounds without burning. Examples of such products are heating devices which release compounds by heating, but not burning, the material. The material may be for example tobacco or other non-tobacco products, which may or may not contain nicotine.

<CIT> discloses a cartridge for an aerosol provision system comprising the cartridge and a control unit.

<CIT> discloses a cartridge and a non-burning type flavour inhaler.

<CIT> discloses an extractor for an aerosol-generating device.

<CIT> discloses a cartridge for use with an aerosol generating device including a housing defining a closed end, an open end, and an aperture between the closed end and the open end.

<CIT> discloses a tobacco blend in a composition for use in a device for generating an inhalable medium.

According to the present invention as defined in claim <NUM> there is provided an aerosol provision device comprising a device housing having a device chamber, a removable receptacle arranged to be at least partially received in the device chamber; the receptacle comprising a base, a wall arrangement extending from the base, the base and wall arrangement defining a heating chamber arranged to removably receive at least a portion of an article comprising aerosol generating material, a heating element for heating at least a portion of an article comprising aerosol generating material received in the heating chamber, wherein the receptacle has a closed channel within the wall arrangement, the closed channel within the wall arrangement being at least partially received within the device chamber when the receptacle is received within the device chamber to provide airflow to the heating chamber.

In an embodiment of the above, the heater element protrudes into the heating chamber from the base.

In a further embodiment of any of the above, the receptacle defines an axis, and the closed channel extends in the axial direction.

In a further embodiment of any of the above, the aerosol provision device comprises an opening to the heating chamber at a proximal end of the receptacle, and wherein the base is at a distal end of the receptacle, and wherein the closed channel extends between the distal and proximal ends.

In a further embodiment of any of the above, the closed channel comprises an air inlet at the proximal end extending in the radial direction.

In a further embodiment of any of the above, the air inlet extends around the opening.

In a further embodiment of any of the above, the closed channel comprises an air outlet to the heating chamber.

In a further embodiment of any of the above, the air outlet is proximate to the base.

In a further embodiment of any of the above, the air outlet extends in a radial direction.

In a further embodiment of any of the above, the wall arrangement comprises an outer wall and an inner wall, wherein the closed channel is formed between the outer wall and inner wall.

In a further embodiment of any of the above, the outer wall extends from the base.

In a further embodiment of any of the above, the outer wall and the base form a cup.

In a further embodiment of any of the above, the cup forms a fluid barrier.

In a further embodiment of any of the above, an air outlet is formed in the inner wall.

In a further embodiment of any of the above, the air outlet is annular around the inner wall.

In a further embodiment of any of the above, the inner wall is removably mounted in the outer wall.

In a further embodiment of any of the above, the outer wall and the base are integrally formed.

In a further embodiment of any of the above, an interior of the inner wall defines the heating chamber.

In a further embodiment of any of the above, the air outlet is between the base and the inner wall.

In a further embodiment of any of the above, the receptacle comprises a plurality of closed channels.

In a further embodiment of any of the above, the aerosol provision device comprises ribs which secure the inner wall to the outer wall, the ribs extending axially along the inner wall and defining a plurality of closed channels between the outer wall and the inner wall.

In a further embodiment of any of the above, the closed channel is annular and extends circumferentially around the inner wall.

In a further embodiment of any of the above, the aerosol provision device comprises a thermal sensor configured to be in thermal communication with the heating element when the heating assembly is secured to the device.

In a further embodiment of any of the above, the thermal sensor is a thermocouple.

In a further embodiment of any of the above, the aerosol provision device comprises a plate which thermally connects the heating element to the thermal sensor.

In a further embodiment of any of the above, the plate is connected to the heating assembly such that the plate is removable from the device with the heating assembly.

In a further embodiment of any of the above, the plate is connected to the device such that the heating assembly is removable from the plate and the device.

In a further embodiment of any of the above, the heating element is removably secured to the base.

In a further embodiment of any of the above, the heating assembly is configured such that rotation of the base relative to the device allows the heating assembly to be secured to or removed from the device.

In a further embodiment of any of the above, the device and the heating assembly comprise complementary interlocking features that are configured to engage in response to rotation of the base relative to the device.

In a further embodiment of any of the above, the heating element comprises a susceptor, and the device comprises at least one inductive coil arranged to energise the susceptor to heating.

In a further embodiment of any of the above, the at least one inductive coil comprises two inductive coils which are separately energiseable.

According to an aspect of the present disclosure, there is provided a system comprising the aerosol provision device of any of the above, and a removable article received within the heater assembly of the device.

According to the present invention as defined in claim <NUM>, there is provided a removable insert for an aerosol provision device, the insert comprising a receptacle defining a heating chamber arranged to removably receive at least a portion of an article comprising aerosol generating material, and a heating element for heating at least a portion of an article comprising aerosol generating material received in the heating chamber, wherein the receptacle comprises an opening at a proximal end, a base at a distal end, and a wall arrangement extending between the proximal and distal ends, wherein a closed channel is defined within the wall arrangement to provide airflow along the wall arrangement.

As used herein, the term "aerosol generating material" includes materials that provide volatilised components upon heating, typically in the form of an aerosol. Aerosol generating material includes any tobacco-containing material and may, for example, include one or more of tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes. Aerosol generating material also may include other, non-tobacco, products, which, depending on the product, may or may not contain nicotine. Aerosol generating material may for example be in the form of a solid, a liquid, a gel, a wax or the like. Aerosol generating material may for example also be a combination or a blend of materials. Aerosol generating material may also be known as "smokable material".

Apparatus is known that heats aerosol generating material to volatilise at least one component of the aerosol generating material, typically to form an aerosol which can be inhaled, without burning or combusting the aerosol generating material. Such apparatus is sometimes described as an "aerosol generating device", an "aerosol provision device", a "heat-not-burn device", a "tobacco heating product device" or a "tobacco heating device" or similar. Similarly, there are also so-called e-cigarette devices, which typically vaporise an aerosol generating material in the form of a liquid, which may or may not contain nicotine. The aerosol generating material may be in the form of or be provided as part of a rod, cartridge or cassette or the like which can be inserted into the apparatus.

An aerosol provision device can receive an article comprising aerosol generating material for heating. An "article" in this context is a component that includes or contains in use the aerosol generating material, which is heated to volatilise the aerosol generating material, and optionally other components in use. A user may insert the article into the aerosol provision device before it is heated to produce an aerosol, which the user subsequently inhales. The article may be, for example, of a predetermined or specific size that is configured to be placed within a heating chamber of the device which is sized to receive the article.

<FIG> shows an example of an aerosol provision device <NUM> for generating aerosol from an aerosol generating medium/material. In broad outline, the device <NUM> may be used to heat a replaceable article <NUM>, also known as a consumable, comprising the aerosol generating medium, to generate an aerosol or other inhalable medium which is inhaled by a user of the device <NUM>.

The device <NUM> comprises a housing <NUM> (including an outer cover <NUM>) which surrounds and houses various components of the device <NUM>. The device <NUM> has an opening <NUM> in one end, through which the article <NUM> may be inserted for heating by a heater assembly <NUM> (refer to <FIG>). In use, the article <NUM> may be fully or partially inserted into the heater assembly <NUM> where it may be heated by one or more components of the heater assembly <NUM>.

The device <NUM> may also include a user-operable control element <NUM>, such as a button or switch, which operates the device <NUM> when pressed. For example, a user may turn on the device <NUM> by operating the switch <NUM>.

The device <NUM> defines a longitudinal axis <NUM>.

<FIG> depicts a schematic cross-sectional front view of the device <NUM> of <FIG>. The device <NUM> comprises the outer cover <NUM>, a first end member <NUM> and a second end member <NUM>. The device <NUM> includes a chassis <NUM>, a power source <NUM>, and an aerosol generating assembly <NUM> including the heater assembly <NUM>. The device <NUM> further comprises at least one electronics module <NUM>.

The outer cover <NUM> forms part of a device shell. The first end member <NUM> is arranged at one end of the device <NUM> and the second end members <NUM> is arranged at an opposite end of the device <NUM>. The first and second end members <NUM>, <NUM> close the outer cover <NUM>. The first and second end members <NUM>, <NUM> form part of the shell. The device <NUM> in embodiments comprises a lid (not shown) which is moveable relative to the first end member <NUM> to close the opening <NUM> when no article <NUM> is in place.

The device <NUM> may also comprise an electrical component, such as a connector/port <NUM>, which can receive a cable to charge a battery of the device <NUM>. For example, the connector may be a charging port, such as a USB charging port. In some examples the connector may be used additionally or alternatively to transfer data between the device <NUM> and another device, such as a computing device.

The device <NUM> includes the chassis <NUM>. The chassis <NUM> is received by the outer cover <NUM>. The aerosol generating assembly <NUM> comprises the heater assembly <NUM> into which, in use, the article <NUM> may be fully or partially inserted where it may be heated by one or more components of the heater assembly <NUM>. The aerosol generating assembly <NUM> and the power source <NUM> are mounted on the chassis <NUM>. The chassis <NUM> is a one piece component.

One-piece component refers to a component of the device <NUM> which is not separable into two or more components following assembly of the device <NUM>. Integrally formed relates to two or more features that are formed into a one piece component during a manufacturing stage of the component.

The first and second end members <NUM>, <NUM> together at least partially define end surfaces of the device <NUM>. For example, the bottom surface of the second end member <NUM> at least partially defines a bottom surface of the device <NUM>. Edges of the outer cover <NUM> may also define a portion of the end surfaces. The first and second end members <NUM> close open ends of the outer cover <NUM>. The second end member <NUM> is at one end of the chassis <NUM>.

The end of the device <NUM> closest to the opening <NUM> may be known as the proximal end (or mouth end) of the device <NUM> because, in use, it is closest to the mouth of the user. In use, a user inserts an article <NUM> into the opening <NUM>, operates the user control <NUM> to begin heating the aerosol generating material and draws on the aerosol generated in the device. This causes the aerosol to flow through the device <NUM> along a flow path towards the proximal end of the device <NUM>.

The other end of the device furthest away from the opening <NUM> may be known as the distal end of the device <NUM> because, in use, it is the end furthest away from the mouth of the user. As a user draws on the aerosol generated in the device, the aerosol flows in a direction towards the proximal end of the device <NUM>. The terms proximal and distal as applied to features of the device <NUM> will be described by reference to the relative positioning of such features with respect to each other in a proximal-distal direction along the axis <NUM>.

The power source <NUM> is, for example, a battery, such as a rechargeable battery or a non-rechargeable battery. Examples of suitable batteries include, for example, a lithium battery (such as a lithium-ion battery), a nickel battery (such as a nickel-cadmium battery), and an alkaline battery. The battery is electrically coupled to the aerosol generating assembly <NUM> to supply electrical power when required and under control of a controller <NUM> to heat the aerosol generating material.

The power source <NUM> and aerosol generating assembly <NUM> are disposed in an axial arrangement, with the power source <NUM> at the distal end of the device <NUM> and the aerosol generating assembly <NUM> at the proximal end of the device <NUM>. Other configurations are anticipated.

The electronics module <NUM> may comprise, for example, a printed circuit board (PCB) <NUM>. The PCB <NUM> may support at least one controller <NUM>, such as a processor, and memory. The PCB <NUM> may also comprise one or more electrical tracks to electrically connect together various electronic components of the device <NUM>. For example, the battery terminals 119a, 119b may be electrically connected to the PCB <NUM> so that power can be distributed throughout the device <NUM>. The connector <NUM> may also be electrically coupled to the battery <NUM> via the electrical tracks.

The aerosol generating assembly <NUM> is an inductive heating assembly and comprises various components to heat the aerosol generating material of the article <NUM> via an inductive heating process. Induction heating is a process of heating an electrically conducting object (such as a susceptor) by electromagnetic induction. An induction heating assembly may comprise an inductive element, for example, one or more inductor coils, and a device for passing a varying electric current, such as an alternating electric current, through the inductive element. The varying electric current in the inductive element produces a varying magnetic field. The varying magnetic field penetrates a susceptor suitably positioned with respect to the inductive element, and generates eddy currents inside the susceptor. The susceptor has electrical resistance to the eddy currents, and hence the flow of the eddy currents against this resistance causes the susceptor to be heated by Joule heating. In cases where the susceptor comprises ferromagnetic material such as iron, nickel or cobalt, heat may also be generated by magnetic hysteresis losses in the susceptor, i.e. by the varying orientation of magnetic dipoles in the magnetic material as a result of their alignment with the varying magnetic field. In inductive heating, as compared to heating by conduction for example, heat is generated inside the susceptor, allowing for rapid heating. Further, there need not be any physical contact between the inductive heater and the susceptor, allowing for enhanced freedom in construction and application.

A temperature sensor <NUM>, for example a thermocouple, is in thermal communication with the susceptor, and is connected to the electronics module <NUM>. In the depicted embodiment, a thermally conductive plate <NUM> is placed between the thermocouple <NUM> and the susceptor to facilitate thermal communication between the thermocouple <NUM> and the susceptor.

The thermocouple <NUM> monitors the temperature of the susceptor during use of the device <NUM> and feeds this information to the electronics module <NUM>. This allows the electronics module <NUM> and the controller <NUM> to monitor and adjust the temperature of the susceptor as may be necessary during use of the device <NUM>, e.g. by adjusting the amount of electrical power supplied by the power source <NUM>. The thermocouple <NUM> can be any suitable thermocouple, such as a platinum rhodium thermocouple (i.e. B type).

Compared to other devices for sensing temperature, the thermocouple <NUM> may facilitate more robust, durable, power-efficient and accurate temperature measurements. Nonetheless, in other examples within the scope of this disclosure, the temperature sensor can be any other suitable temperature sensor, such as a resistance temperature detector, thermistor, infra-red sensor etc..

<FIG> shows a close up view of part of the aerosol generating assembly <NUM> in cross-section that includes the heater assembly <NUM> and an inductor coil assembly <NUM>.

The aerosol generating assembly <NUM> comprises the inductor coil assembly <NUM> and the heater assembly <NUM>. The inductor coil assembly <NUM> extends around the heater assembly <NUM>. The inductor coil assembly <NUM> comprises a coil support <NUM>. The inductor coil assembly <NUM> includes an inductor coil <NUM> wrapped around (i.e. surrounding) the heater assembly <NUM>, disposed in a groove <NUM> defined in the support <NUM>. The inductor coil assembly <NUM> is fixedly mounted in the device housing <NUM>. The coil support <NUM> may form part of the device housing <NUM>.

The heater assembly <NUM> includes a heating element <NUM> for heating the article <NUM> during use. In the exemplified embodiment of <FIG>, the heating element is a susceptor arrangement <NUM> (herein referred to as "a susceptor"). In other examples, the heating element could be of another type, for example a resistive heater. The susceptor <NUM> of this example is a blade-shaped susceptor <NUM>. The article <NUM> can be inserted onto or around the susceptor <NUM>. The blade-shaped susceptor <NUM> may have a constant rectangular cross-section along the majority of its axial length and then taper to a blade tip <NUM>. In other examples, the axial cross-section may vary along the axial length of the susceptor <NUM> to the blade tip <NUM>.

Although a blade-shaped susceptor <NUM> is depicted, it is to be understood that any other suitable shape or form of susceptor <NUM> may be used within the scope of this disclosure. For example, the susceptor <NUM> could be pin-shaped e.g. with a constant circular cross-section along its axial length that tapers to a pin tip, or rod-shaped (e.g. a cylindrical rod or a square rod) with a constant or varying cross-section along its axial length that omits a tip or tapered portion. In further examples, the susceptor <NUM> may be a tubular member within which the article <NUM>/aerosol generating material is received. Such a susceptor is an outer susceptor. In such an example, the susceptor may define a peripheral wall (e.g. an annular wall) that defines at least part of a heating chamber within which the article <NUM> can be received and heated. In such an example, the susceptor surrounds the article <NUM>, instead of the article <NUM> surrounding the susceptor as in the blade-shaped embodiment discussed above. It will be understood that the cross-sectional profile of the outer susceptor may be formed in a variety of profile shapes.

In further examples, multiple susceptors (e.g. two or more separate susceptors) may also be provided, and may be of differing or similar configurations (e.g. pin-shaped, blade-shaped, rod-shape or tubular-type etc.), as required.

The susceptor <NUM> is formed from an electrically conducting material suitable for heating by electromagnetic induction. The susceptor in the present example is formed from a carbon steel. It will be understood that other suitable materials may be used, for example a ferromagnetic material such as iron, nickel or cobalt.

In other embodiments, the feature acting as the heating element may not be limited to being inductively heated. The feature, acting as a heating element, may therefore be heatable by electrical resistance. The heater assembly <NUM> may therefore comprise electrical contacts for electrical connection with the apparatus for electrically activating the heating element by passing a flow of electrical energy through the heating element. In such embodiments, inductive coil assembly <NUM> can be omitted as appropriate.

The inductor coil <NUM> is made from an electrically conducting material. In this example, the inductor coil <NUM> is made from Litz wire/cable which is wound in a helical fashion to provide a helical inductor coil <NUM>. Litz wire comprises a plurality of individual wires which are individually insulated and are twisted together to form a single wire. Litz wires are designed to reduce the skin effect losses in a conductor. In the example device <NUM>, the inductor coil <NUM> is made from copper Litz wire which has a circular cross section. In other examples the Litz wire can have other shape cross sections, such as rectangular. The inductor coil <NUM> can be connected to the PCB <NUM> to control the activation of inductive heating therefrom using the electronics module <NUM> and switch <NUM>.

The number of inductor coils used may also differ. For example, although the heater assembly <NUM> shown in <FIG> includes an inductor coil assembly <NUM> with only a single coil <NUM>, it should be understood that the inductor coil assembly <NUM> can feature any number of suitable coils. Additional coils may be used to provide different heating zones with different heating characteristics for the susceptor <NUM> (e.g. provide different heating conditions to different areas along the axial length of the susceptor <NUM> and/or provide different heating conditions to the susceptor <NUM> at different times or for different use cases). Additional coils may also be provided to generate heating in additional susceptors that may be disposed in the heater assembly <NUM> (not shown).

The heater assembly <NUM> also includes a receptacle <NUM> (shown in more detail in <FIG>). The receptacle <NUM> defines a heating chamber <NUM> within which the article <NUM> is received during use. In the depicted embodiment, the receptacle <NUM> is an annular body that encircles the susceptor <NUM> and provides an annular space between the susceptor <NUM> and the receptacle within which the article <NUM> can be received and heated during use.

The coil support <NUM> and opening <NUM> define a device chamber <NUM> within the device housing <NUM> that receives the receptacle <NUM> and interacts therewith in order to secure the heater assembly <NUM> in place. In embodiments, the device chamber <NUM> is defined by another feature other than the coil support <NUM>. The coil support <NUM> forms an internal wall. The internal wall is cup shaped.

The receptacle <NUM> is removeably disposed within the chamber <NUM>, such that it can be removed therefrom and replaced therein during use. This feature facilitates the cleaning of the receptacle <NUM> (and other heater assembly components part thereof), as well as replacement of the receptacle <NUM> (and other heater assembly components part thereof) in the event of breakage or failure.

In the depicted example, the receptacle <NUM> is completely disposed inside the chamber <NUM>. In other examples, when the receptacle <NUM> is received in the chamber <NUM> a portion of the receptacle <NUM> (e.g. such as a lip or a flange at its proximal end) may still extend outside of the device chamber <NUM>. In such examples, the receptacle <NUM> may therefore be 'partially removably disposed' in the chamber <NUM>. This disclosure covers all such examples.

<FIG> show the heater assembly <NUM> and the receptacle <NUM> in more detail. The receptacle <NUM> includes annular outer and inner walls 231a, 231b that are concentric with each other about the longitudinal axis <NUM> of the heater assembly <NUM>. The outer wall 231a forms an outer shell. The inner wall 231b forms an inner shell. As shown in <FIG> and <FIG>, when the heater assembly <NUM> is inserted into the device housing chamber <NUM>, the longitudinal axis <NUM> of the heater assembly <NUM> is substantially co-axial with the longitudinal axis <NUM> of the device <NUM>.

The outer wall 231a extends axially from an opening/inlet end 233a to an opposing base 233b of the receptacle <NUM>. The outer wall 231a may define the base 233b itself, and be integrally formed therewith. Alternatively, the base 233b could be attached to the outer wall 231a separately. The outer wall 231a forms a cup. The opening/inlet end 233a is so called, because it is the end of the heater assembly <NUM> that sits in the inlet <NUM> of the device <NUM> when the receptacle is inserted into the device housing chamber <NUM>. Accordingly, as discussed above in relation to the device <NUM>, the opening/inlet end 233a may also be referred to as the proximal end (or mouth end) of the heater assembly <NUM>, whilst the base 233b may be referred to as the distal end of the heater assembly <NUM>.

The base 233b defines an aperture <NUM> therein within which the heating element <NUM> is received and protrudes (axially) therefrom. The heating element <NUM> defines a base <NUM> and an anchoring flange <NUM> around the base <NUM> that is received in the aperture <NUM>. The anchoring flange <NUM> and base <NUM> may be press-fit into the aperture <NUM>. However, any other suitable method of securing the heating element <NUM> in place in the receptacle <NUM> may be used e.g. insert molding, interference fit, threaded fitment etc. In embodiments, aperture <NUM> could instead be a blind cavity/recess or may be omitted completely depending on the securing method used to attached the heating element <NUM> in place in the receptacle <NUM>.

The heating element <NUM> is fixedly attached to the receptacle <NUM>, such that it is a part of the receptacle <NUM> itself and is supported thereby. In this manner, the heating element <NUM> is removable from the device housing chamber <NUM>, with and as part of the receptacle <NUM>.

The heating element <NUM> forms a fluid-tight seal with the base 233b of the receptacle <NUM>, such that the base 233b of the receptacle <NUM> is not permeable to fluids. The heating chamber <NUM> is thereby made fluid-tight at the distal end thereof. Any residue or condensate byproducts which are created during the aerosolisation process are therefore confined to the receptacle <NUM>, where they gather at the base 233b. The receptacle <NUM> can then be removed from the device <NUM> and cleaned or replaced, without the device <NUM> being exposed to the residue or condensate, which could otherwise cause damage to internal components of the device <NUM>.

In the embodiment shown, the outer wall 231a and the base 233b of the receptacle <NUM> together form a cup, which defines a fluid-tight heating chamber <NUM>, providing further protection of the device <NUM> by limiting the residue and condensate which the interior of the device <NUM> is exposed to. In the embodiment shown, the outer wall 231a and the base 233b are integrally formed to provide the cup and the fluid-tight heating chamber <NUM>.

In embodiments where the device <NUM> is provided with a thermocouple <NUM> or other thermal sensor, a plate <NUM> may be provided to thermally connect the heating element <NUM> and the thermocouple <NUM> (as discussed above in relation to <FIG>). The plate <NUM> may form part of the receptacle <NUM>, and be removable therewith. On insertion of the receptacle <NUM> into the device <NUM>, the plate <NUM> engages with the thermocouple <NUM> for thermal communication therewith. Alternatively, the plate may form part of the device <NUM>, and on insertion of the receptacle <NUM> into the device <NUM>, a bottom of the heating element <NUM> engages with the plate <NUM> for thermal communication therewith.

The heating element <NUM> may additionally be separately removable from the receptacle <NUM> itself. For example, the heating element <NUM> could be removeably fixed to the receptacle <NUM> instead of fixedly attached thereto. For example, by being threadably received therein, being received by a bayonet fitting therein, or using connectors on the heating element <NUM> that interference fit with corresponding connectors which can be pulled apart.

This may facilitate cleaning and/or replacement of the heating element <NUM>. This improvement in replacement of the heating element <NUM> may be useful in the event that the heating element <NUM> is broken or has failed and needs to be replaced without replacement of the entire receptacle <NUM>, or where the receptacle <NUM> needs to be replaced by the heating element <NUM> is still usable with a new receptacle but the removability may also be useful for interchanging different heating elements <NUM> for different use cases; for example, when a certain use case or article <NUM> may demand a different shape/type of heating element <NUM> to another.

The inner wall 231b extends axially from the proximal end 233a towards the base 233b but does not connect to the base 233b. The inner wall 231b stops axially short of the base 233b to form an axial gap G, or air outlet, proximate the base, and between the inner wall 231b and the base 233b. In the depicted example, the axial gap G provides an annular gap around the heating element <NUM> between the base 233b and the inner wall 231b.

The inner wall 231b features a tapered surface <NUM> at the proximal end 233a. The tapered surface <NUM> tapers at an angle towards the longitudinal axial <NUM> from the proximal end 231b. The tapered surface <NUM> may help facilitate insertion of the article <NUM> into the heater assembly <NUM> and heating chamber <NUM>. For example, it may facilitate correct alignment of the article <NUM> when it is insert into the heating chamber <NUM> around the heating element <NUM>.

The outer wall 231a and inner wall 231b are spaced radially apart and are, for example, connected by radially extending ribs <NUM>. The ribs <NUM> secure the inner wall 231b in place within the outer wall 231a. There are a discrete number of ribs <NUM> disposed between the outer and inner walls 231a, 231b around the circumference of the walls 231a, 231b. In the illustrated example, there are four such ribs <NUM> spaced equally around the circumference of the walls 231a, 231b. However, any suitable number and spacing of ribs <NUM> can be used.

In other examples, the outer and inner walls 231a, 231b could be connected by other means, for example by pin connections which allow a nearly continuous space between the outer and inner walls 231a 231b for airflow in, for example, a single, substantially annular passage or channel.

In the depicted embodiment, the ribs <NUM> extend axially along the whole of the length of the inner wall 231b. However, the ribs <NUM> may extend any suitable axial distance between the walls 231a, 231b that is sufficient to provide the required support for holding the walls 231a, 231b concentrically in place relative to each other.

The combination of the outer wall 231a, inner wall 231b and ribs <NUM> define slots <NUM>, or air inlets, at the proximal end 233a and form passages <NUM> or channels that extend axially within the receptacle <NUM>. The passages or channels are closed; that is, they comprise an inlet and an outlet and a fluidly-isolated section between the inlet and outlet, such that air is passed from the inlet to the outlet. The fluidly-isolated section is fluidly isolated from the heating chamber <NUM> and from an exterior of the receptacle <NUM>, except from at the inlet and the outlet.

The number and size of slots <NUM> and passages <NUM> can be varied as necessary depending on the size, spacing and number of ribs <NUM>. Moreover, the slots <NUM> and passages <NUM> needn't be defined at the proximal end 233a. For example, the ribs <NUM> could be present at any suitable axial location within the receptacle <NUM>, e.g. nearer the base 231b or midway along the axial length of the walls 231a, 231b. Moreover, the slots <NUM> and passages <NUM> could instead provide a single (e.g. substantially annular, and extending around substantially the whole circumference of the inner wall) slot <NUM>/passage <NUM> that extends axially between the inner and outer walls 231a, 231b.

The passages <NUM> are used as airflow passages that permit the communication of airflow from the exterior of the device <NUM> to the heating chamber <NUM> and the aerosol generating materials therein during use. The inlet of airflow from the proximal end 233a via slots <NUM> and passages <NUM> is convenient, as the user is unlikely to block airflow to such a region when using the device <NUM>.

The passages <NUM> exit into the annular space provided by gap G, or air outlet, which in use allows airflow to be communicated from the passages <NUM> into the heating chamber <NUM>, and through the aerosol generating material/article <NUM> therein.

The presence of passages <NUM> between the inner and outer walls 231a, 231b can allow for improved control of the airflow and resistance to airflow through the passages <NUM>. For example, it may allow the use of airflow modifying features (e.g. airflow constrictors) to be placed in the passages <NUM> (e.g. extending between walls 231a, 231b and/or from ribs <NUM>) in order to provide a more consistent airflow and/or desirable airflow resistance to be communicated through the article <NUM> and to the user in use.

The device <NUM> and/or heater assembly <NUM> could provide additional arrangements of airflow passages for supplying airflow for use of the device <NUM>. For example, airflow passage(s) could also be provided in the side of the device, or defined between the inner wall 231b and the article <NUM> itself. Airflow passage(s) could also be directed from the distal end of the device <NUM> and up through the base 233b instead or in addition.

The outer and inner wall 231a, 231b configuration of the receptacle <NUM> can facilitate improvements in the amount of insulation provided between the heating element <NUM> and the device housing <NUM> (e.g. compared to a single-walled receptacle <NUM>). The passages <NUM>, used as airflow passages, may facilitate yet further improvement in the amount of insulation provided between the heating element <NUM> and the device housing <NUM> (e.g. as the (relatively cool external) airflow can absorb excess heat from the inner and outer walls 231a, 231b). The amount of insulation provided by the heater assembly <NUM> can be an important consideration for the device <NUM>, as it may be necessary to prevent the device <NUM> becoming too hot in the user's hand or the temperatures becoming troublesome for other device components. By providing an air gap in the receptacle <NUM>, it is possible to facilitate an improvement in the amount of insulation required in the device housing, leading to a compact device housing.

As discussed in the passage above, the receptacle <NUM> is removably disposed within the chamber <NUM>, such that it can be removed therefrom and replaced therein during use. In being removable, the receptacle <NUM> may also be replaced by a receptacle with a different configuration, for example with a different configuration of air passages. This may provide for customisability of the device <NUM> for consumer benefit, or for interaction with different consumables.

In particular, in the depicted embodiments, the receptacle <NUM> is configured to interact with the chamber <NUM> in such a way that rotation of the receptacle <NUM> relative to the device housing <NUM> allows it to be engaged and disengaged in response to rotation of the receptacle <NUM>.

The receptacle <NUM> and the device housing <NUM> include complementary interlocking features that are configured to engage or disengage in response to rotation of the receptacle <NUM> relative to the device housing <NUM>.

Within the context of this disclosure, it should be understood that 'engage' relates to an engagement that holds the receptacle <NUM> in place sufficiently in the device housing <NUM> for use of the device <NUM>, and 'disengage' relates to the releasing of such an engagement that allows the receptacle <NUM> to be removed from the device housing <NUM> (e.g. without having to remove other components of the device housing <NUM> or destroying parts of the device housing <NUM>).

As shown in <FIG> and <FIG>, the complementary interlocking features are provided by grooves <NUM>, <NUM> (or recesses) on an outer surface <NUM> of the receptacle <NUM> (i.e. radially outward facing surface of the outer wall 231a) and corresponding protrusions <NUM> on the device housing <NUM>. The protrusions <NUM> extend radially inward from an inner surface of the device housing chamber <NUM> relative to the longitudinal axis <NUM> of the device <NUM>.

As best shown in <FIG>, when the heater assembly <NUM> is inserted into the device housing chamber <NUM> it is done so with the protrusion <NUM> radially aligned with the groove <NUM> (i.e. relative to longitudinal axis <NUM>). Protrusion <NUM> and groove <NUM> are sized such that the protrusion <NUM> does not 'engage' (as discussed above) the receptacle <NUM> when inserted in the groove <NUM>.

When the heater assembly <NUM> is subsequently rotated about the longitudinal axis <NUM> relative to the device housing <NUM>, the protrusion <NUM> is rotated out of radial alignment with groove <NUM>, across the outer surface <NUM>, and into radial alignment with groove <NUM>. Protrusion <NUM> and groove <NUM> are sized and shaped such that the protrusion <NUM> 'engages' the receptacle <NUM> when inserted in the groove <NUM>. This engagement can be provided by a sufficient interference fit/contact being made between the protrusion <NUM> and groove <NUM>. For example, the grooves <NUM> define a ridge <NUM> that extends radially from the groove <NUM> to meet the outer surface <NUM>. When the protrusions <NUM> are aligned in the grooves <NUM> they are axially above the ridge <NUM> and radially overlap the ridge <NUM>. If the receptacle <NUM> should try to be removed from the device housing chamber <NUM> with the protrusion <NUM> in this position (e.g. pulled out from the chamber <NUM> along the longitudinal axis <NUM>), the ridge <NUM> will provide interfering contact with the protrusion <NUM> to prevent its removal.

It will be understood that subsequently rotating the receptacle <NUM> out of radial alignment with the groove <NUM>/ridge <NUM> and back into radial alignment with the groove <NUM> will result in the receptacle <NUM> being 'disengaged' from the protrusion <NUM> and thus the device housing <NUM>. This allows subsequent removal of the receptacle <NUM> from the chamber <NUM> and device housing <NUM>.

The grooves <NUM>, <NUM> can feature tapered/contoured surfaces <NUM>, <NUM> which, along with the outer surface <NUM> and the protrusions <NUM>, can be shaped/contoured as required to provide a particular resistance to rotation between grooves <NUM>, <NUM>. Moreover, the shape, (radial) depth and (axial) height of the grooves <NUM> and corresponding (radial and axial) lengths of the protrusion <NUM> can also be used to vary the degree of engagement between the receptacle <NUM> and the device housing <NUM> (e.g. by adjusting the degree of the interference fit/contact between the protrusion <NUM> and grooves <NUM> and ridges <NUM> in the engaged position) and associated resistance to rotation provided thereby.

Tailoring the resistance to rotation and degree of engagement in this manner can not only be used to ensure the heater assembly <NUM> is sufficiently held in the engaged position for use, but that it is also easy enough to rotate to the disengaged position to facilitate removal. Tailoring of these features can also be used to improve the user's perceived 'smoothness' and/or 'quality' of the rotation and removal process of the heater assembly <NUM>.

Although four sets of grooves <NUM>, <NUM> and protrusions <NUM> are shown spaced around the circumference of the chamber <NUM> and the heater assembly <NUM>, any suitable number and spacing could be used within the scope of this disclosure.

In the depicted example, the grooves <NUM> extend the full axial length of the outer wall 231a (i.e. from proximal end 233a to base 233b). This can facilitate ensuring the correct axial and radial alignment of the heater assembly <NUM> during insertion into the device housing <NUM>, as protrusions <NUM> can be easily aligned and guided along the grooves <NUM> during the insertion process.

The grooves <NUM> are also shown radially aligned with the ribs <NUM> relative to the longitudinal axis <NUM>. This may give the grooves <NUM> additional structural support to resist bending during insertion of the heater assembly <NUM>. However, the grooves <NUM> need not be placed in such a position, and can be positioned any other suitable radial position.

The protrusions <NUM> and grooves <NUM> are depicted at the inlet <NUM> and the proximal end 231a. However, within the scope of this disclosure the protrusions <NUM> and/or grooves <NUM> can be placed at any suitable axial position within the chamber <NUM> and along the outer surface <NUM>, respectively. The axial length and positioning of the grooves <NUM> can also be varied accordingly.

Although in the depicted example the grooves <NUM>, <NUM> are disposed on the receptacle <NUM> and the protrusions <NUM> disposed on the device housing <NUM>, within the scope of this disclosure, the grooves <NUM>, <NUM> could alternatively be disposed on the device housing <NUM> (i.e. in the chamber <NUM>) and the protrusions <NUM> disposed on the receptacle <NUM> instead.

Although one particular set of complementary interlocking features to achieve the removable rotation engagement between the receptacle <NUM> and the device housing <NUM> in the form of grooves <NUM>, <NUM> and protrusions <NUM> has been depicted and explained above, the present disclosure extends to any other suitable implementation of such rotational complementary interlocking features.

In one example, the complementary interlocking features could be complementary threaded portions disposed on the receptacle <NUM> (e.g. on the outer surface <NUM>) and within the chamber <NUM>. In such an example, the receptacle <NUM> could be screwed into and out of engagement with the device housing <NUM> via rotation thereof relative to the device housing <NUM>.

In another example, the complementary interlocking features could provide a bayonet fitting type rotational engagement. In such an example, the receptacle <NUM> could feature radially extending pins on the outer surface <NUM> that can be received in corresponding L-shaped slots or recesses provided in the chamber <NUM>. Alignment and rotation of the pins in the L-shaped slots would secure them in place to 'engage' the receptacle <NUM> to the device housing <NUM> (commonly known as a bayonet fitting). The L-shaped slots and pins could also alternatively be provided on the receptacle <NUM> and chamber <NUM>, respectively, instead.

In any of the above discussed rotational engagement examples, a biasing member, such as a spring (not shown), could be supplied within the chamber <NUM>/device housing <NUM>. The biasing member can be configured to be compressed in response to insertion of the receptacle <NUM> into the device housing chamber <NUM> (e.g. by the base 233b) to provide a biasing force that opposes the insertion (but that does not override the engagement, when the receptacle <NUM> is placed into the engaged position within the housing <NUM>).

Claim 1:
An aerosol provision device (<NUM>) comprising:
a device housing (<NUM>) having a device chamber (<NUM>);
a removable receptacle (<NUM>) arranged to be at least partially received in the device chamber (<NUM>); the receptacle (<NUM>) comprising:
a base (233b);
a wall arrangement extending from the base (233b), the base (233b) and wall arrangement defining a heating chamber (<NUM>) arranged to removably receive at least a portion of an article (<NUM>) comprising aerosol generating material;
a heating element (<NUM>) for heating at least a portion of an article comprising aerosol generating material received in the heating chamber;
wherein the receptacle (<NUM>) has a closed channel within the wall arrangement, the closed channel within the wall arrangement being at least partially received within the device chamber (<NUM>) when the receptacle (<NUM>) is received within the device chamber (<NUM>) to provide airflow to the heating chamber (<NUM>).