The present disclosure relates to aerosol generating devices for use with aerosol generating articles having an aerosol generating substrate, such as a tobacco substrate. More particularly, the present disclosure relates to heat diffusers for aerosol generating devices for transferring heat from a heating element of an aerosol generating device to an aerosol generating article.

Some aerosol generating devices are configured to heat an aerosol-forming substrate sufficiently to cause generation of an aerosol without combusting the substrate. These are known as "heat-not-burn" devices. Heat-not burn devices can be desirable because, since the aerosol- forming substrate is not combusted with the heat-not-burn devices, by-products of combustion and pyrolysis are not generated with the aerosol, and thus are not delivered to the user for inhalation.

One commercially available heat-not-burn device is the Philip Morris International IQOS® device, which is configured to receive and heat heatsticks. Some commercially available heatsticks are the Philip Morris International HEETS® or Heatsticks®. Heatsticks are tobacco- containing articles that resemble conventional cigarettes but differ from conventional cigarettes in that they comprise a tobacco substrate formed from a crimped tobacco sheet having a plurality of substantially parallel ridges or corrugations. The IQOS® heating device includes a heating blade that is configured to pierce the tobacco substrate of a heatstick inserted into the device, such that the heating blade contacts and heats the tobacco substrate, primarily via conduction, such that volatile compounds of the aerosol forming substrate release a vapour that cools to form an aerosol that may be inhaled by a user.

Philip Morris International HEETS® and Heatsticks® heatsticks are manufactured under stringent conditions to ensure the articles have a particular size and the aerosol-forming substrate has a particular structure and composition to enable proper heating and flavour delivery when used with a corresponding IQOS® heating device. High quality tobaccos and blends are used, and a variety of flavours are offered.

However, it would be desirable to provide a consumer with a broader array of options of aerosol generating articles that may be used with a particular aerosol generating device. For example, some aerosol-generating articles may not be suitable for use with a device having a heating blade for piercing the aerosol-forming substrate. It would be desirable to provide an aerosol-generating device that is adaptable for use with aerosol-generating articles that require a heating blade to pierce the aerosol-forming substrate and for aerosol generating articles that require heating without the aerosol-forming substrate being pierced by a heating blade. It would also be desirable to provide an aerosol-generating device that is adaptable for use with aerosol- generating articles of different sizes. In various aspects of the present invention there is provided a system comprising an aerosol generating device and a heat diffuser. The aerosol generating device comprise a receptacle for receiving an elongate aerosol generating article comprising a solid aerosol forming substrate. The aerosol generating device further comprises an elongate heating element extending into the receptacle and configured to penetrate the aerosol generating article and to contact the aerosol forming substrate when the article is received in the receptacle of the device. The heat diffuser is removably receivable in the receptacle of the device. The heat diffuser comprises a thermally conductive body defining a cavity for receiving the elongate heating element of the device when the heat diffuser is received in the receptacle of the device. The body has a top and a bottom and a plurality of discrete air passageways extending from the bottom to the top.

The heat diffuser is configured to facilitate heat transfer from the heating element of the aerosol generating device to an aerosol generating article received in the receptacle of the device via conduction.

The heat diffuser comprises a thermally conductive body, which facilitates heat transfer from the heating element of the aerosol generating device to the heat diffuser. The body of the heat diffuser also defines a plurality of air passageways extending from the bottom to the top, which enable air to be drawn through the heat diffuser from the bottom to the top. Accordingly, the heat diffuser is configured to be heated by the heating element of an aerosol generating device and is further configured to transfer heat from the thermally conductive body to air drawn through the plurality of air passageways defined by the body.

In use, when the heat diffuser of the present invention is received in the receptacle of an aerosol generating device, heat from the heating element of the device may be transferred to the body of the heat diffuser. An aerosol generating article for use with the aerosol generating device may comprise a distal end, comprising the aerosol forming substrate, and an opposite proximal end, comprising a mouthpiece. The distal end of the aerosol generating article may be received in the receptacle of the device. When a user draws on the mouthpiece of the article, air may be drawn into the receptacle of the device, through the plurality of air passageways in the body of the heat diffuser, from the bottom to the top, and through the aerosol generating article, from the distal end to the proximal end. As the air passes through the passageways of the heat diffuser, heat is transferred from the heat diffuser to the air. The heated air is drawn from the passageways of the heat diffuser at the top of the heat diffuser into the distal end of the aerosol generating article, where heat is transferred from the heated air to the aerosol-forming substrate. Volatile compounds in the aerosol-forming substrate may be heated by the heated air and release a vapour that is entrained in the heated air. The vapour may cool as it is drawn through the article towards the mouthpiece and form an aerosol. The aerosol may then be delivered to the user at the mouthpiece for inhalation.

In this arrangement, the aerosol forming substrate of the aerosol generating article is primarily heated by the heated air drawn into the aerosol-generating article from the heat diffuser. As such, the aerosol forming substrate is primarily heated by convection. Convection heating may be more suitable for certain aerosol forming substrates than direct heating via conduction, such as from a heater in direct contact with the aerosol forming substrate.

Typically, the receptacle of the aerosol generating device is configured to receive the heat diffuser and at least a distal end of an aerosol-generating article comprising the aerosol-forming substrate. Typically, the heat diffuser, the receptacle of the aerosol generating device and the aerosol generating article each have a longitudinal axis. The longitudinal axis of the heat diffuser may extend between the bottom and the top of the thermally conductive body. The longitudinal axis of the receptacle may extend between a substantially closed end to an open end configured to receive the heat diffuser and the aerosol generating article. The longitudinal axis of the aerosol generating article may extend between a distal end comprising the aerosol forming substrate and a proximal end or mouthpiece end comprising a mouthpiece. The aerosol generating article may be in the form of a rod. Typically, the heat diffuser, the receptacle of the aerosol generating device and the aerosol generating article may be arranged such that their longitudinal axes are substantially aligned when the heat diffuser and the distal end of the aerosol generating article are received in the receptacle of the device.

Where the receptacle of the device comprises a closed end and an open end, the heat diffuser may be received in the receptacle at or around the closed end and oriented with the bottom of the body towards the closed end and the top of the body towards the open end. When a distal portion of an aerosol generating article is received in the receptacle, the distal end face of the aerosol generating article may abut the top surface at the top of the body.

The receptacle of the aerosol generating device may be any suitable shape and size for receiving the heat diffuser and at least a portion of an aerosol-generating article. Preferably the receptacle is cylindrical. Preferably the receptacle includes a cylindrical outer wall, an open end and a closed end. The receptacle is configured to receive at least a portion of an aerosol generating article. The receptacle is also configured to receive the heat diffuser. The aerosol generating article and the heat diffuser may be inserted into the receptacle through the open end of the receptacle.

The thermally conductive body of the heat diffuser may have an outer diameter substantially similar to an inner diameter of the receptacle of the aerosol generating device. The length of the body may be at least 50% of the outer diameter of the body.

As used herein, "diameter" refers to a maximum distance across a transverse section (normal to the longitudinal axis). An object having a diameter may have any suitable cross- sectional shape. Preferably, the cross-sectional shape is circular.

As used herein a diameter that is "substantially the same" as another diameter has a diameter that differs from the other diameter by less than 15%, preferably less than 10%. Similarly, a value that is "substantially the same" as another value is a value that differs from the other value by less than 15%, preferably less than 10%.

The body defines a length from the top to the bottom. Preferably, the length of the body is less than the length of the receptacle of the aerosol generating device so that at least a portion of the receptacle proximate the open end may receive and retain the aerosol generating article when the heat diffuser is received in the receptacle. Preferably, the heat diffuser is removably receivable in the receptacle. In such embodiments, the heat diffuser may act as an adapter that permits the aerosol generating device to be employed with a variety of aerosol generating articles. For example, a removable heat diffuser in the receptacle of an aerosol generating device may enable the aerosol generating device to be used with aerosol generating articles having a shorter length than would have been possible without the heat diffuser in the receptacle. That is, the aerosol generating article configured to be received by the receptacle when the heat diffuser is not received in the receptacle may have a relatively longer rod comprising the aerosol forming substrate, and the aerosol generating article configured to be received by the receptacle when the heat diffuser is received in the receptacle may have a relatively shorter rod comprising the aerosol forming substrate. The removable heat diffuser may also enable an aerosol generating device to be used with aerosol generating articles which may not be amenable for penetration by the elongate heating element. The heat diffusers described in the present disclosure may provide a convenient way for a user to configure a given aerosol generating device for use with a variety of aerosol generating articles. Various heat diffusers may be used with a single aerosol generating device for increasing the number of different consumable aerosol generating articles that may be employed with the device, thereby increasing functionality and usefulness of the device.

The heat diffusers described in the present disclosure may be used with any suitable aerosol generating device but are particularly well suited for use with aerosol generating devices that have a receptacle configured to receive an aerosol generating article and that have an elongate heating element that extends into the receptacle. The aerosol generating device may comprise any suitable heating element. The heating element may comprise a resistive heating element, an inductive heating element, or a combination thereof.

The heating element may comprise a resistive heating component, such as one or more resistive wires or other resistive elements. The resistive wires may be in contact with a thermally conductive material to distribute heat produced over a broader area. Examples of suitable conductive materials include aluminium, copper, zinc, nickel, silver, and combinations thereof. For purposes of this disclosure, if resistive wires are in contact with a thermally conductive material, both the resistive wires and the thermally conductive material are part of the heating element.

The heating element may comprise an inductive heating element. For example, the heating element may comprise a susceptor material. As used herein, the term 'susceptor' refers to a material that is capable to convert electromagnetic energy into heat. When located in an alternating electromagnetic field, typically eddy currents are induced and hysteresis losses may occur in the susceptor causing heating of the susceptor.

The susceptor may be formed from any material that can be inductively heated to a temperature sufficient to generate an aerosol from the aerosol generating substrate. Preferred susceptors comprise a metal or carbon. A preferred susceptor may comprise or consist of a ferromagnetic material, for example ferritic iron, a ferromagnetic alloy, such as ferromagnetic steel or stainless steel, and ferrite. A suitable susceptor may be, or comprise, aluminium.

Preferred susceptors are metal susceptors, for example stainless steel. However, susceptor materials may also comprise or be made of graphite, molybdenum, silicon carbide, aluminum, niobium, Inconel alloys (austenite nickel-chromium-based superalloys), metallized films, ceramics such as for example zirconia, transition metals such as for example Fe, Co, Ni, or metalloids components such as for example B, C, Si, P, Al. A susceptor preferably comprises more than 5%, preferably more than 20%, preferably more than 50% or 90% of ferromagnetic or paramagnetic materials. Preferred susceptors may be heated to a temperature in excess of 250 degrees Celsius. Suitable susceptors may comprise a non-metallic core with a metal layer disposed on the non-metallic core, for example metallic tracks formed on a surface of a ceramic core.

If the heating element comprises a susceptor, the device may also comprise one or more induction coils configured to induce eddy currents and/or hysteresis losses in the susceptor material, which results in heating of the susceptor material.

The aerosol generating device may comprise control electronics operably coupled to the resistive heating element or induction coil. The control electronics are configured to control heating of the heating element. The control electronics may be internal to the housing.

The control electronics may be provided in any suitable form and may, for example, include a controller or a memory and a controller. The controller may include one or more of an Application Specific Integrated Circuit (ASIC) state machine, a digital signal processor, a gate array, a microprocessor, or equivalent discrete or integrated logic circuitry. Control electronics may include memory that contains instructions that cause one or more components of the circuitry to carry out a function or aspect of the control electronics. Functions attributable to control electronics in this disclosure may be embodied as one or more of software, firmware, and hardware. The electronic circuitry may comprise a microprocessor, which may be a programmable microprocessor. The electronic circuitry may be configured to regulate a supply of power. The power may be supplied to the heating element or induction coil in the form of pulses of electrical current.

If the heating element is a resistive heating element, the control electronics may be configured to monitor the electrical resistance of the heating element and to control the supply of power to the heating element depending on the electrical resistance of the heating element. In this manner, the control electronics may regulate the temperature of the resistive element.

If the heating components comprise an induction coil and the heating element comprises a susceptor material, the control electronics may be configured to monitor aspect of the induction coil and to control the supply of power to the induction coil depending on the aspects of the coil such as described in, for example, WO 2015/177255. In this manner, the control electronics may regulate the temperature of the susceptor material. The aerosol generating device may comprise a temperature sensor, such as a thermocouple, operably coupled to the control electronics to control the temperature of the heating elements. The temperature sensor may be positioned in any suitable location. For example, the temperature sensor may be configured to insert into the aerosol generating substrate or in contact or proximity with the heating element. The sensor may transmit signals regarding the sensed temperature to the control electronics, which may adjust heating of the heating elements to achieve a suitable temperature at the sensor.

Regardless of whether the aerosol generating device includes a temperature sensor, the device is preferably configured to heat an aerosol generating substrate of an aerosol generating article received in the receptacle to an extent sufficient to generate an aerosol without combusting the aerosol generating substrate.

The control electronics may be operably coupled to a power supply, which may be internal to the housing. The aerosol generating device may comprise any suitable power supply. For example, a power supply of an aerosol generating device may be a battery, or set of batteries. The batteries maybe rechargeable, as well as removable and replaceable. Any suitable battery may be used.

Any suitable configuration of heat diffusers may be used with the aerosol generating device to allow a variety of aerosol generating articles to be employed with the device. As air passes through the passageways, the air is heated by the body. Preferably, the air is heated sufficiently to cause aerosol to be generated from an aerosol generating substrate of an aerosol generating article, without combusting the substrate.

The body of the heat diffuser comprises thermally conductive material to transfer heat from the heating element of the aerosol generating device to air passing through the passageways and to the aerosol generating substrate of the aerosol generating article that is received by the receptacle of the device and is contact with, or in proximity to, the body. The body may comprise any suitable thermally conductive material. Examples of suitable conductive materials include, but are not limited to, aluminium, copper, zinc, nickel, silver, and combinations thereof.

As used herein, "thermally conductive" refers to a material having a thermal conductivity of at least 10 W/m.k, preferably at least 40 W/m.k, more preferably at least 100 W/m.k at 23 degrees Celsius and a relative humidity of 50%. In preferred embodiments, the sleeve comprises material having a thermal conductivity of at least 40 W/m.k, preferably at least 100 W/m.k, more preferably at least 150 W/m.k, and even more preferably at least 200 W/m.k at 23 degrees Celsius and a relative humidity of 50%. In some embodiments the heat diffuser may be configured for use with an aerosol generating device comprising an elongate heating element extending into the receptacle. In such embodiments, the thermally conductive body of the heat diffuser may comprise a cavity for receiving the heating element of the device. The cavity may be configured such that the heating 5 element directly contacts the body when the heat diffuser is received in the receptacle and the heating element is inserted into the cavity. In other embodiments, the cavity may be configured such that there may be a separation between the heating element and the body of the heat diffuser when the heat diffuser is received in the receptacle. When there is a separation between the cavity and the heating element, the heating element may be sufficiently close to the body to heat o the body, such that the body may sufficient heat air passing through the passageways, which may then heat the aerosol generating substrate.

The body may have any suitable mass. In embodiments where the aerosol-generating device comprises a heating element, preferably, the body has a larger thermal mass relative to the heating element. While a body with increased thermal mass may take longer to heat up, the5 body may retain heat for longer periods of time and may provide a more regulated heating effect.

The body of the heat diffuser may have any suitable shape and dimensions, depending on one or more of the desired thermal mass, the desired surface area to volume ratio and the internal shape and dimensions of the receptacle of the aerosol generating article. In some examples, the body is generally cylindrical, but the body may be any other suitable shape. 0 The body may have an outer diameter that is substantially the same as the inner diameter of the receptacle of the aerosol generating device. For example, the outer diameter of the body of the heat diffuser may be the same as the inner diameter of the receptacle or may be within 15% of the inner diameter of the receptacle. Preferably, the outer diameter of the body of the heat diffuser is within about 10% of the inner diameter of the receptacle. The body of the heat5 diffuser may be retained in the receptacle by interference fit.

In some examples, the body of the heat diffuser has a diameter in a range from about 5 mm to about 10 mm. The cross-sectional shape of the body may be circular, but may be any other suitable shape.

The length of the body from the bottom to the top of the body may be at least 50% of the0 outer diameter of the body. For example, the length of the body may be between 50% and 100% of the outer diameter of the body, or the length of the body may be greater than the outer diameter of the body. Heat diffusers having longer bodies may have increased thermal mass relative to heat diffusers having shorter bodies. Preferably, the length of the body is less that the length of the receptacle of the aerosol generating device. The length of the receptacle is defined as the distance between the ends of the receptacle. In embodiments in which the receptacle has a closed end and an open end, the length of the receptacle is defined as the distance between the closed end of the receptacle and the open end of the receptacle. In these embodiments, the bottom of the body of the heat diffuser may be configured to abut the closed end of the receptacle. The top of the body of the heat diffuser may be configured to contact the aerosol generating article when the article and the heat diffuser are inserted into the receptacle of the aerosol generating device. Preferably, a portion of the receptacle proximate the open end may receive may receive and retain an aerosol generating article when the heat diffuser is received in the receptacle.

In some embodiments in which the heat diffuser is configured for use with an aerosol generating device comprising an elongate heating element extending into the receptacle, the length of the body of the heat diffuser may be less than the distance that the elongate heating element of the device extends into the receptacle so that a portion of the heating element extends through the cavity of the body of the heat diffuser and beyond the top of the body of the heat diffuser when the heat diffuser is inserted into the receptacle. Thus, a portion of an aerosol generating article may be directly heated by a portion of the elongate heating element (the portion extending beyond the top of the body) if the article is inserted into the receptacle such that the portion of the heating element penetrates the article. In other embodiments in which the heat diffuser is configured for use with an aerosol generating device comprising an elongate heating element extending into the receptacle, the length of the body of the heat diffuser may be the same as the distance that the elongate heating element extends into the receptacle of the aerosol generating device or may be greater that the distance that the elongate heating element extends into the receptacle. In some examples, the length of the body of the heat diffuser is in a range from about 5 mm to about 30 mm, preferably from about 10 mm to about 15 mm.

The outer diameter of the body of the heat diffuser may be substantially the same along the entire length of the body. Preferably, the outer diameter of the body is substantially the same along at least 50% of the length of the body. The body of the adaptor may be porous to allow air to pass through the body. Preferably, the body is non-porous, so that air passes through the body only through the passageways, which are preferably non-porous. The plurality of air passageways defined by the body are discrete. In other words, the plurality of passageways are substantially not interconnected. As such, air may be substantially inhibited or prevented from flowing between the air passageways, through the thermally conductive body. Providing a plurality of discrete passageways through the thermally conductive body may be straightforward and cost effective to manufacture while enabling fine control of the thermal mass, surface to volume ratio and resistance to draw of the thermally conductive body. This may facilitate delivery of a consistent, desired user experience for each aerosol generating device and heat diffuser.

The passageways defined by the body may have any suitable dimensions and shape. The passageways extend between the top and the bottom of the thermally conductive body. The passageways are open at both ends to allow air to flow through the thermally conductive body, from the bottom to the top. The passageways may all have the same dimensions and shape, or at least some of the passageways may have different dimensions and shapes than other passageways. Preferably, the passageways have uniform sizes and shapes. The passageways may be substantially cylindrical. Preferably the passageways have a substantially constant diameter along their length. Preferably, the passageways are substantially linear. The linear passageways may extend in substantially the same direction as the longitudinal axis of the thermally conductive body. In other words, the linear passageways may be substantially parallel with the longitudinal axis of the thermally conductive body. The linear passageways may be substantially parallel to each other. The passageways may have any suitable transverse cross- section. For example, the passageways may have a circular, elliptical, square, or rectangular transverse cross-section. Preferably the passageways have a substantially circular transverse cross-section.

The passageways may allow substantially free flow of air through the body from the bottom to the top without substantially increasing resistance to draw when used in combination with the aerosol generating article and the aerosol generating article. For example, the transverse sectional surface area defined by at least some of the passageways may be 0.1 mm ² or greater. Preferably, the transverse sectional surface area defined by at least some of the passageways are 0.2 mm ² or greater. In some embodiments, the resistance to draw (RTD) of the heat diffuser is between about 10 to 130 mm H ₂ 0, preferably between about 40 to 100 mm H ₂ O. The RTD of a specimen refers to the static pressure difference between the two ends of the specimen when it is traversed by an air flow under steady conditions in which the volumetric flow is 17.5 millilitres per second at the output end. The RTD of a specimen can be measured using the method set out in ISO Standard 6565:2002 with any ventilation blocked. The body of the heat diffuser may define any suitable number of passageways for air flow. For example, the body may define from about 10 passageways to about 1 ,000 passageways. Preferably, the body defines from about 20 passageways to about 500 passageways.

The number, shape and dimensions of the passageways may be determined based on the desired characteristics of the heat diffuser. For example, passageways having smaller cross- sectional area tend to result in greater heating of the air passing through the passageway, while passageways having larger cross-sectional areas tend to result in less resistance to flow of air and thus less resistance to draw. For example, a larger number of passageways tend to result in a greater heating of the air passing through the body than a smaller number of passageways of the same shape and dimensions. Accordingly, the number, size and shape of the passageways may be balanced to achieve desired heating and airflow characteristics.

In some examples, the passageways are generally cylindrical from the bottom of the body of the heat diffuser to the top of the body of the heat diffuser. In some examples, the passageways have a generally triangular transvers cross-sectional shape along the length of the body. For example, the body may comprise a plurality of fins that extend outwardly from a central portion of the body. For example, the fins may extend radially from the central portion of the body. Where the body defines a cavity for receiving an elongate heating element of an aerosol generating device, the cavity may be defined in the central portion of the body. The fins preferably run the length of the body. The passageways may be defined between adjacent fins. The fins may provide both high thermal mass and a large amount of surface area for heat exchange with air flowing between the fins. The fins may have any suitable thickness, and the body may have any suitable number of fins. The thickness and number of fins may be determined by the desired characteristics of the heat diffuser, such as thermal mass, heating of air through the passageways between the fins, and resistance to flow of air and thus resistance to draw. In some examples, the body comprises from about 10 fins to about 100 fins, such as from about 15 fins to about 50 fins.

The top surface of the body of the receptacle may have any suitable shape. Preferably at least a portion of an aerosol generating article contacts the top surface of the body of the heat diffuser when the article and the heat diffuser are inserted into the receptacle of the aerosol generating device. In some embodiments, the top surface of the body of the heat diffuser may be substantially planar so that substantially the entire sop surface of the body contacts to the aerosol generating article when the article is inserted into the receptacle of the device. In some embodiments, the top of the body may have a top surface that is substantially non-planar. In such examples, the periphery of the top of the body may contact the aerosol generating article when the article is inserted into the receptacle into which the heat diffuser is inserted. An interior portion of the top of the body of the heat diffuser may be arranged such that it is positioned a distance away from the aerosol generating article when the article is inserted into the receptacle. For example, an interior portion, such as the centre, of the top of the body may be positioned at least about 0.1 mm away from the aerosol generating article, at least about 0.3mm away from the aerosol generating article, from about 0.1 mm to about 5 mm away from the aerosol generating article or from about 0.1 mm to about 1 mm away from the aerosol generating article.

Where an interior portion of the top of the body of the heat diffuser is positioned a distance away from the aerosol generating article, increased peripheral heating of the aerosol generating article may be achieved due to direct contact between the article and the top of the body at the periphery. This may alleviate problems that may arise from heating via a central heating element. For example, if the elongate heating element of the aerosol generating device extends generally into the centre of the receptacle and if the cavity of the body of the heat diffuser that receives the heating element is in the centre of the body, heating will occur from the middle to the outer surfaces of the body, and thus from the middle to the outer surfaces of the aerosol generating article. As heat is transferred to the airflow through the passageways of the body, the portions of the body furthest from the heating element cool the most or take the longest to reheat. Thus, peripheral regions of the aerosol generating article also tend to be heated to an extent less than central portions of the aerosol generating article. However, by providing a heat diffuser with a body having a top surface having an interior portion positioned a distance away from the aerosol generating article, heating through conduction may occur at the periphery of the aerosol generating article. In addition, the body may have additional thermal mass and surface area at the periphery to enhance peripheral heating. When the top of the body of the heat diffuser has an interior portion positioned a distance away from the aerosol generating article, more uniform heating across the entire face of the aerosol generating article may be achieved, rather than reduced heating at the periphery.

In some examples, the top surface of the body of the heat diffuser may be substantially concave. The heat diffuser may comprise a thermally conductive element extending from the top of the body. The thermally conductive element is preferably configured to penetrate into an aerosol generating article when the aerosol generating article is inserted into the receptacle of the device into which the heat diffuser is inserted. Preferably, the thermally conductive element contacts aerosol generating substrate of the aerosol generating article when the article is inserted into the receptacle containing the heat diffuser. Heat diffusers having a thermally conductive element extending from the top of the body may heat the aerosol generating substrate through conduction, via contact with the thermally conductive element and contact with at least a portion of the top surface of the body, and convection through air that is heated as it travels through passageways defined by the body of the heat diffuser.

The thermally conductive element may have any suitable dimensions. The thermally conductive element preferably has a width less than an inner diameter of the receptacle of the device and preferably has a width less than an outer diameter of the article into which it may be inserted. For example, the thermally conductive element may have a width in a range from about 0.5 mm to about 9 mm; preferably from about 1 mm to about 5 mm. The width of the thermally conductive element may taper. For example, the width of the thermally conductive element may be greater at its base in proximity to the top of the body and may be less at its free end distal to the top of the body.

In some embodiments where the heat diffuser comprises a cavity for receiving a heating blade of an aerosol generating device, the thermally conductive element of the heat diffuser may have a similar size and shape to the heating blade. In other words, the thermally conductive element may have a complimentary size and shape to the cavity of the heat diffuser. This may enable more than one heat diffuser to be stacked on top of each other within a receptacle of an aerosol-generating device. This may enable an aerosol generating device to be used with aerosol generating articles of different lengths.

The thermally conductive element of the heat diffuser may have any suitable thickness. Preferably, the thickness of the thermally conductive element is sufficiently small to allow the thermally conductive element to readily penetrate the aerosol generating article. In some examples, the thermally conductive element has a thickness from about 0.1 mm to about 2 mm, such as from about 0.5 mm to about 1 mm.

The thermally conductive element extending from the top of the body of the heat diffuser may have any suitable length. The length is preferably less than a length of aerosol generating substrate within the aerosol generating article that the thermally conductive element is configured to penetrate. In some example, the thermally conductive element has a length from about 1 mm to about 10 mm, such as from about 2 mm to about 5 mm.

In some embodiments, the heat diffuser comprises more than one thermally conductive element extending from the top of the body. The heat diffuser may comprise a plurality of thermally conductive elements extending from the top of the body. For example, the heat diffuser may comprise two, three, four or five thermally conductive elements extending from the top of the body. Where the heat diffuser comprises more than one thermally conductive element, the thermally conductive elements may be arranged in any suitable configuration for penetrating aerosol forming substrate of an aerosol generating article. Any suitable aerosol generating article comprising aerosol generating substrate may be used with a heat diffuser and aerosol generating device described herein.

The aerosol generating article may comprise a filter upstream of the aerosol generating substrate. For example, the filter may be proximate a mouth end of the aerosol generating article. Any suitable filter, such as cellulose acetate tow, may be used. The filter may be wrapped in plug wrap. The filter may be coaxialiy aligned with a rod of aerosol generating substrate, and the filter and rod may be held together with, for example, tipping paper.

The aerosol generating article may also comprise an aerosol cooling element downstream of the aerosol generating substrate. As used herein, 'aerosol-cooling element' refers to a component of an aerosol-generating article located downstream of the aerosol-forming substrate such that, in use, an aerosol formed by volatile compounds released from the aerosol generating substrate passes through and is cooled by the aerosol cooling element before being inhaled by a user. Any suitable aerosol cooling element known in the art may be employed. For example, aerosol cooling elements disclosed in EP2814342 B1 may be incorporated into aerosol generating articles of the present disclosure. The aerosol generating article may also comprise a hollow tube between the aerosol generating substrate and the aerosol cooling element. Any suitable hollow tube known in the art may be employed. For example, hollow tubes, such as cellulose acetate hollow tubes, disclosed in EP2814342 B1 may be incorporated into aerosol generating articles of the present disclosure.

In some examples, the aerosol generating article comprises an aerosol generating substrate, a hollow tube, an aerosol-cooling element, and a mouthpiece filter. These four elements may be arranged sequentially and in coaxial alignment and may be assembled by a cigarette paper to form a rod. The rod has a mouth-end, which a user inserts into his or her mouth during use, and a distal end located at the opposite end of the rod to the mouth end. Elements located between the mouth-end and the distal end can are considered to be upstream of the mouth-end or, alternatively, downstream of the distal end.

The aerosol generating article may comprise any suitable aerosol generating substrate capable of releasing volatile compounds when heated. The aerosol generating substrate may comprise nicotine. The nicotine containing aerosol generating substrate may comprise a nicotine salt matrix. The aerosol generating substrate may comprise plant-based material. The aerosol- generating substrate may comprise tobacco, and preferably the tobacco-containing material contains volatile tobacco flavor compounds, which are released from the aerosol generating substrate upon heating.

The aerosol generating substrate may comprise homogenized tobacco material. Homogenized tobacco material may be formed by agglomerating particulate tobacco. Where present, the homogenized tobacco material may have an aerosol-former content of equal to or greater than 5% on a dry weight basis, and preferably between greater than 5% and 30% by weight on a dry weight basis.

The aerosol generating substrate may alternatively or additionally comprise a non- tobacco-containing material. The aerosol generating substrate may comprise homogenized plant- based material.

The aerosol generating substrate may comprise, for example, one or more of: powder, granules, pellets, shreds, spaghettis, strips or sheets containing one or more of: herb leaf, tobacco leaf, fragments of tobacco ribs, reconstituted tobacco, homogenized tobacco, extruded tobacco and expanded tobacco.

The aerosol generating substrate may comprise at least one aerosol-former. The aerosol- former may be any suitable known compound or mixture of compounds that, in use, facilitates formation of a dense and stable aerosol and that is substantially resistant to thermal degradation at the operating temperature of the aerosol-generating device. Suitable aerosol-formers are well known in the art and include, but are not limited to: polyhydric alcohols, such as triethylene glycol, 1 ,3-butanediol and glycerine; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Particularly preferred aerosol formers are polyhydric alcohols or mixtures thereof, such as triethylene glycol, 1 ,3-butanediol and, most preferred, glycerine. The aerosol generating substrate may comprise other additives and ingredients, such as flavorants. The aerosol generating substrate preferably comprises nicotine and at least one aerosol-former. In a particularly preferred embodiment, the aerosol-former is glycerine.

The aerosol generating substrate may be provided on or embedded in a thermally stable carrier. In a preferred embodiment, the carrier is a tubular carrier having a thin layer of the solid substrate deposited on its inner surface, or on its outer surface, or on both its inner and outer surfaces. Such a tubular carrier may be formed of, for example, a paper, or paper like material, a non-woven carbon fiber mat, a low mass open mesh metallic screen, or a perforated metallic foil or any other thermally stable polymer matrix. Alternatively, the carrier may take the form of powder, granules, pellets, shreds, spaghettis, strips or sheets. The carrier may be a non-woven fabric or fiber bundle into which tobacco components have been incorporated. The non-woven fabric or fiber bundle may comprise, for example, carbon fibers, natural cellulose fibers, or cellulose derivative fibers.

According to a further aspect of the present invention, there is provided a system comprising: a heat diffuser according to the first aspects of the present invention; and an aerosol generating device comprising a receptacle for receiving the heat diffuser and heating element for heating the heat diffuser when the heat diffuser is received in the receptacle.

Any features described above with reference to the first aspect may be equally applicable to the second aspect and any features described with reference to the second aspect may be equally applicable to the first aspect. Reference will now be made to the drawings, which depict one or more aspects described in this disclosure. However, it will be understood that other aspects not depicted in the drawings fall within the scope and spirit of this disclosure. Like numbers used in the figures refer to like components, steps and the like. However, it will be understood that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number. In addition, the use of different numbers to refer to components in different figures is not intended to indicate that the different numbered components cannot be the same or similar to other numbered components. The figures are presented for purposes of illustration and not limitation. Various structures or components may be shown diagrammatically or removed from some of or all the views to better illustrate aspects of the depicted embodiments, or where inclusion of such structures or components is not necessary to an understanding of the various exemplary embodiments described herein. Schematic drawings presented in the figures are not necessarily to scale.

FIG. 1 is a schematic sectional view of an aerosol generating article that may be used with a heat diffuser of the present invention FIG. 2A is a schematic sectional view of an aerosol generating article ready for insertion into, and of a heat diffuser of the present invention retained within, the aerosol generating device depicted in FIG. 1.

FIG. 2B is a schematic sectional view of the aerosol generating article and the heat diffuser depicted in FIG. 2A retained within the aerosol generating device.

FIG. 3A is a schematic perspective view of a heat diffuser of the present invention.

FIG. 3B is a schematic perspective view of the heat diffuser depicted in FIG. 3A in a receptacle of an aerosol generating device.

FIG. 4A is a schematic perspective view of a heat diffuser of the present invention. FIG. 4B is a schematic sectional view of the heat diffuser depicted in FIG. 4A retained in an aerosol generating device.

FIG. 4C is a schematic sectional view of an aerosol generating article and the heat diffuser depicted in FIG. 4A inserted into the aerosol generating device depicted in FIG. 4B.

FIG. 5A is a schematic perspective view of a heat diffuser of the present invention. FIG. 5B is a schematic sectional view of the heat diffuser depicted in FIG. 5A retained in an aerosol generating device.

FIG. 5C is a schematic sectional view of an aerosol generating article and the heat diffuser depicted in FIG. 5A inserted into the aerosol generating device depicted in FIG. 5B.

Referring now to FIG. 1 , an aerosol generating device 200 is shown. The device 200 includes a housing 210 defining the receptacle 220, which is configured to receive a heat diffuser and an aerosol generating article. The device 200 also includes an elongate heating element 230 extending into the receptacle 220. The heating element 230 may comprise an electrically resistive heating component. The receptacle 220 has an open end 222 through which the heat diffuser and the aerosol generating article may be inserted. The receptacle 220 has a closed end 224, which the heat diffuser may abut when inserted into the receptacle 220. In addition, the device 200 includes a power supply 240 and control electronics 250 that cooperate to control heating of heating element 230. Preferably, the control electronics 250 are configured to cause the heating element to heat to an extent sufficient to cause aerosol generation from an aerosol generating substrate of an aerosol generating article used with the device 200, without combusting the substrate.

Referring now to FIGS. 2A-B, an aerosol generating article 100 is shown ready for introduction into a receptacle 220 of an aerosol generating device 200 (FIG. 2A) and retained within the device (FIG. 2B). A heat diffuser 400 is disposed in a receptacle 220 and about a heating element 230 of the device 200. The heat diffuser comprises a thermally conductive body defining a cavity into which the heating element 230 is inserted. The body of the heat diffuser 400 includes a plurality of discrete air passageways 410 that extend the length of the body, from the bottom to the top. The passageways are substantially linear and have a substantially circular transverse cross-section. The passage ways are aligned substantially parallel with a longitudinal axis of the body. As air passes through the passageways 410 the air may be heated by the body of the heat diffuser 400, which is in thermal contact with the heating element 230 of the device 200.

The aerosol generating article 100 comprises a housing 110 in which an aerosol generating substrate 300 is contained. The aerosol generating article 100 may include a filter 140 at the mouth end 102 downstream of the aerosol generating substrate 300. The end 104 of the article 100 opposite the mouth end 102 may contact the body of the heat diffuser 400 when the heat diffuser 400 and the article 100 are inserted in the receptacle 220 of the device 200.

A user may insert the mouth end 102 of the article 100 in his or her mouth and draw on the article 100, which causes air to flow through body of the heat diffuser 400. More specifically, air flows through passageways 410 defined by the body of the heat diffuser 400. The body of the heat diffuser 400 is heated by the heating element 230 of the device 200. The heated body of the heat diffuser 400 heats the air flowing through the passageways 410. As the user draws on the mouth end 102 of the article 100, the heated air from the passageways 410 contacts the aerosol generating substrate 300 to generate aerosol, which may be entrained in the heated air. The aerosol is delivered through the mouth end 102 of the article 100 for delivery to the user by inhalation.

The direction of air flow is shown by the arrows in FIG. 2B.

Referring now to FIGS. 3A-B, a heat diffuser 400 (FIG. 3A) and the heat diffuser in a receptacle 220 of an aerosol generating device (FIG. 3B) are shown. The heat diffuser 400 has a body 450 having a length L that extends from the bottom 452 to the top 454 of the body 450. The body 450 has a diameter D. Preferably, the length L of the body 450 is at least 50% of the diameter D to provide sufficient thermal mass to the heat diffuser 400. In the depicted embodiment, the body 450 comprises a plurality of fins 422 that extend away from a central body portion 418 that defines the cavity 415 configured to receive, and preferably contact, the heating element 230 of the aerosol generating device. The passageways 410 are defined between the fins 422. Preferably, the body 450 of the heat diffuser 400 is configured to be retained in the receptacle 220 by interference fit and passageways 410 may be formed between an inner surface of the receptacle 220 and between fins 422 of the heat diffuser 400.

Referring now to FIGS. 4A-C, an alternative embodiment of a heat diffuser 400 is shown. Like the embodiment depicted in FIG. 3A, the heat diffuser 400 depicted in FIGS. 4A-C has a body 450 comprising a plurality of fins 422 that extend away from a central body portion 418 that defines a cavity 425 configured to receive a heating element 230 that extends into a receptacle 220 of an aerosol generating device 200. The body 450 of the heat diffuser 400 has a top 454 and a bottom 452, and air passageways 410 are defined between the fins 422. Unlike the heat diffuser 400 depicted in FIG. 3A, the heat diffuser 400 depicted in FIGS. 4A-C has a concave top 454 such that the periphery of the body 450 defined by the distal edges of the fins 422 are higher than the central body portion 418. Accordingly, when the heat diffuser 400 and an aerosol generating article 100 are inserted into a receptacle 220 of an aerosol generating device 200, a portion of the end of the article 100 opposite the mouth end 102 of the article 100 contacts the peripheral portion of the body 450 of the heat diffuser 400 (FIG. 4C). In addition, the periphery of the top 454 of the body 450 of the heat diffuser 400 has increased mass relative to the central portion. Together, the direct contact between the periphery of the top 454 of the body 450 of the heat diffuser 400 and the aerosol generating article 100 and the increased thermal mass of the periphery of the top 454 of the body 450 of the heat diffuser 400 may result in more even heating of the aerosol generating substrate 300 in the article 100, which might otherwise be concentrated in the center due to the central position of the heating element 230.

The aerosol generating article 100 depicted in FIG. 4C differs from the article 100 depicted in FIGS. 2A-B. However, it will be understood that any suitable aerosol generating article may be used with the devices 200 and heat diffusers 400 described herein. The article 100 depicted in FIG. 4C includes an aerosol generating substrate 300, a hollow cellulose acetate tube 120, an aerosol cooling element 130, and a filter 140. These four elements are arranged sequentially and in coaxial alignment and are surrounded by a cigarette paper 110 to form a rod. The rod has a mouth-end 102 proximate the filter 140, which a user inserts into his or her mouth during use, and a distal end located at the opposite end of the rod to the mouth end. Referring now to FIGS. 5A-C, an alternative embodiment of a heat diffuser 400 is shown. Like the embodiments depicted in FIGS. 3A and 4A, the heat diffuser 400 depicted in FIGS. 5A- C has a body 450 comprising a plurality of fins 422 that extend away from a central body portion 418 that defines a cavity 425 configured to receive a heating element 230 that extends into a receptacle 220 of an aerosol generating device 200. The body 450 of the heat diffuser 400 has a top 454 and a bottom 452, and air passageways 410 are defined between the fins 422. Unlike the heat diffuser 400 depicted in FIGS. 3A and 4A, the heat diffuser 400 depicted in FIGS. 5A-C has a thermally conductive element 420 extending from the top 454 of the body 450. The width of the thermally conductive element 420 tapers as it extends away from the top 454 of the body 450. That is, the base 426 of the thermally conductive element 420 has a width greater than the free end 424 that extends away from the top 454 of the body 450. The thermally conductive element 420 is configured to penetrate into the aerosol generating article 100 to contact aerosol generating substrate 300 in the article 300 when the article 100 and the heat diffuser 400 are inserted into the receptacle 220 of the aerosol generating device 200. Thus, the heat diffuser 400 depicted in FIGS. 5A-C may heat the substrate 300 via conduction through contact with the thermally conductive element 420 and convection through heating of air in passageways 410.

All scientific and technical terms used herein have meanings commonly used in the art unless otherwise specified. The definitions provided herein are to facilitate understanding of certain terms used frequently herein.

As used in this specification and the appended claims, the singular forms "a", "an", and

"the" encompass embodiments having plural referents, unless the content clearly dictates otherwise.

As used in this specification and the appended claims, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise.

As used herein, "have", "having", "include", "including", "comprise", "comprising" or the like are used in their open-ended sense, and generally mean "including, but not limited to". It will be understood that "consisting essentially of, "consisting of, and the like are subsumed in "comprising," and the like.

The words "preferred" and "preferably" refer to embodiments of the invention that may afford certain benefits under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the disclosure, including the claims. Any direction referred to herein, such as "top," "bottom," "left," "right," "upper," "lower," and other directions or orientations are described herein for clarity and brevity are not intended to be limiting of an actual device or system. Devices and systems described herein may be used in a number of directions and orientations.

The embodiments exemplified above are not limiting. Other embodiments consistent with the embodiments described above will be apparent to those skilled in the art.