Cartridge for aerosol-generating system with liquid absorbing element

Abstract

A cartridge for an aerosol-generating system, comprising: a housing defining an airflow passage from an air inlet to an air outlet; a liquid reservoir within the housing; at least one liquid absorbing element in fluid communication with, and preferably within, the gas flow path; and a heater assembly extending into or across the airflow passage, the heater assembly including a heating element and configured to wick liquid from the liquid reservoir across the heating element, the heater assembly positioned in the airflow passage between the at least one liquid absorbing element and the air outlet.

Description

[0001] The present disclosure relates to a cartridge for an aerosol-generating system. The present disclosure also relates to an aerosol-generating system comprising a cartridge and an aerosol-generating device.

[0002] It is known to provide an aerosol-generating device for generating an inhalable vapour. Such devices can heat an aerosol-forming substrate contained in a cartridge without combusting the aerosol-forming substrate. The aerosol-generating device can comprise a heating device. The heating device can be an induction heating device and can comprise an induction coil and a susceptor. The susceptor can be part of the device or can be part of the cartridge.

[0003] On heating to a target temperature, the aerosol-forming substrate vaporises to form an aerosol. The aerosol-forming substrate can be in solid form or in liquid form. Liquid aerosol-forming substrate can be contained in a liquid storage portion and can be delivered to the heating element via a capillary member.

[0004] A consumer can carry an aerosol-generating device and a cartridge for use therewith wherever they go. It is generally preferred that the device and cartridge are of small size to enhance portability.

[0005] It is desirable to provide a cartridge having a compact design. It is desirable to provide an aerosol-generating device having a compact design. It is desirable to provide an aerosol-generating system having a compact design.

[0006] It is desirable to provide a cartridge for an aerosol-generating device that can reduce or avoid leakage of aerosol-forming substrate. It is desirable to provide a cartridge for an aerosol-generating device that can reduce or avoid leakage of aerosol-forming substrate during transport.

[0007] According to a first aspect of the present disclosure, there is provided a cartridge for an aerosol-generating system. The cartridge can comprise a housing. The housing can define an airflow passage from an air inlet to an air outlet. The cartridge can comprise a liquid reservoir within the housing. The cartridge can comprise at least one liquid absorption element in fluid communication with, and preferably within, the airflow passage. The cartridge can comprise a heater assembly. The heater assembly can extend into or across the airflow passage. The heater assembly can comprise a heating element. The heater assembly can be configured to wick liquid from the liquid reservoir across the heating element. The heater assembly can be positioned in the airflow passage between the at least one liquid absorption element and the air outlet.

[0008] In one embodiment, there is provided a cartridge for an aerosol-generating system. The cartridge comprises a housing defining an airflow pathway from an air inlet to an air outlet; a liquid reservoir within the housing; at least one liquid absorption element in fluid communication with, and preferably within, the airflow pathway; and a heater assembly extending into or across the airflow pathway, the heater assembly comprising a heating element and being configured to wick liquid from the liquid reservoir across the heating element, the heater assembly being positioned in the airflow pathway between the at least one liquid absorption element and the air outlet.

[0009] The at least one liquid absorption element is external to the liquid reservoir and is positioned to absorb liquid that has escaped from the heater assembly into the airflow pathway. The at least one liquid absorption element can be positioned within the airflow pathway in such a way that air can flow through the liquid absorption element to reach the heater assembly. The at least one liquid absorption element can be positioned within the airflow pathway such that it is positioned external to the airflow generated within the airflow pathway from the air inlet to the air outlet during use. For example, the at least one liquid absorption element can be held in a recess or blind cavity within the airflow pathway. The at least one liquid absorption element can be positioned within the airflow pathway in such a way that air can flow through the at least one liquid absorption element to reach the heater assembly.

[0010] The at least one liquid absorption element can be positioned in fluid communication with the airflow pathway at a position upstream of the heater assembly. As used herein, the term “upstream” refers to the direction of airflow through the airflow pathway from the air inlet to the air outlet. Thus, in the direction of airflow from the air inlet to the air outlet, a position in the airflow pathway upstream of the heater assembly is closer to the air inlet than the heater assembly is to the air inlet.

[0011] Preferably, the air outlet is at a mouth end of the cartridge, and a connection end of the cartridge is opposite the mouth end, and the at least one liquid absorption element is positioned between the heater assembly and the connection end. A pressure or temperature difference between the liquid reservoir and the external environment, or gravity, can cause the aerosol-forming substrate to migrate towards the connection end of the cartridge and through the heater assembly. This can occur both in use and between uses once the cartridge is unsealed. Advantageously, by absorbing the aerosol-forming substrate, the position of the at least one liquid absorption element prevents liquid aerosol-forming substrate from exiting the cartridge through the connection end.

[0012] As used herein, “aerosol-forming substrate” means a substrate capable of releasing volatile compounds that can form an aerosol. Such volatile compounds can be released by heating the aerosol-forming substrate. The aerosol-forming substrate is typically contained in the liquid reservoir.

[0013] The connection end can be connectable to a device comprising a power supply. The cartridge and the device can together form an aerosol-generating system. In that system, the device and the cartridge cooperate to generate an inhalable aerosol.

[0014] The cartridge can comprise a mouthpiece through which a user draws air in use. The mouthpiece can be positioned at a mouth end of the cartridge. The mouth end of the housing can comprise the mouthpiece. The mouthpiece can be integrally formed with the housing. The mouthpiece can be formed separately from the housing and connected to the housing. The mouthpiece can be connected to the housing by an interference fit. The mouthpiece can be connected to the housing by an adhesive.

[0015] The cartridge can comprise a longitudinal axis extending between a mouth end and a connection end of the cartridge. The mouth end can also be referred to as a proximal end of the cartridge and the connection end can also be referred to as a distal end of the cartridge.

[0016] The airflow pathway can extend from an air inlet at the connection end to an air outlet at the mouth end.

[0017] The at least one liquid-absorbing element can comprise one or more open-pore porous members. Advantageously, the one or more porous members are capable of retaining liquid. This is beneficial so that the at least one liquid-absorbing element absorbs and retains aerosol-forming substrate that has migrated into the airflow pathway.

[0018] The at least one liquid-absorbing element can comprise a sponge material. The at least one liquid-absorbing element can comprise a foam material.

[0019] The at least one liquid-absorbing element can be retained in a recess defined in the housing. The recess can have an open end facing the air outlet end and a closed end opposite the open end. The closed end ensures that the liquid-absorbing element is securely retained in the airflow pathway and reduces the likelihood of liquid escaping. The closed end can also provide an engagement surface on the cartridge that can interact with the device when the cartridge is connected to the device.

[0020] The housing can comprise an outer housing and an inner housing, at least a portion of the airflow pathway being within the inner housing and the reservoir being defined between the outer housing and the inner housing.

[0021] The at least one liquid-absorbing element can comprise an inner liquid-absorbing element, wherein the inner liquid-absorbing element is retained in a recess defined in the inner housing. Advantageously, the inner liquid-absorbing element acts as a reservoir for aerosol-forming substrate droplets that exit the heater assembly. Aerosol-forming substrate that is not vaporised is less likely to exit the airflow pathway through the mouthpiece or through the connection end if it is retained in the inner liquid-absorbing element. The inner liquid-absorbing element can comprise a sponge material. The inner liquid-absorbing element can comprise a foam material.

[0022] The outer housing can at least partially, and preferably completely, define the inner housing. The air inlet can be provided in the outer housing.

[0023] The heater assembly can be supported in the inner housing. The heater assembly can extend into or across the airflow passage within the inner housing. Advantageously, this arrangement allows air to flow past the heater assembly (at the time of its use), so that the vaporised aerosol-forming substrate is entrained in the airflow and condenses to form an aerosol. This arrangement can allow a large surface area of the heater to be exposed to the airflow, thereby allowing a large amount of aerosol to be generated in a small cartridge.

[0024] The cartridge can have an initial configuration in which the liquid reservoir is sealed from the heater assembly. The inner housing can be configured to move relative to the outer housing to unseal the liquid reservoir, and thereby allow liquid from the liquid reservoir to pass to the heater assembly. Advantageously, this configuration reduces the likelihood of aerosol-forming substrate escaping from the liquid reservoir before or between uses.

[0025] The initial configuration can be a pre-use configuration of the cartridge. If the cartridge is in the initial configuration before use, the aerosol-forming substrate can be securely held in the cartridge. In the initial configuration, the aerosol-forming substrate can be sealed from the external environment, and in particular protected from contact with oxygen and moisture. This can allow for a longer shelf life of the cartridge.

[0026] The inner housing can comprise an engagement surface. The engagement surface of the inner housing can be accessible from the exterior of the cartridge to allow the inner housing to be moved out of the initial position. The engagement surface can be located on the distal end of the cartridge. The cartridge can be configured such that the engagement surface can be pushed by a pushing member, causing the inner housing to move out of the initial configuration. Advantageously, this configuration means that the liquid reservoir will remain sealed until the inner housing is moved in a particular way, meaning that the aerosol-forming substrate is securely sealed when the cartridge is not in use.

[0027] The engagement surface can be defined by the outer housing. The engagement surface can only be accessible through a connection end of the outer housing. Advantageously, this means that the reservoir can be more likely to remain sealed when the cartridge is not in use, as the engagement surface is only accessible from a single direction and through a single aperture in the outer housing. This means that the cartridge is less likely to be accidentally unsealed when not in use, for example in a user's pocket or during transportation. The aperture in the connection end of the outer housing can be an air inlet. The aperture in the connection end of the outer housing can also be an engagement opening that allows access to the engagement surface. Alternatively or additionally, the air inlet can be provided by a different opening in the outer housing.

[0028] The inner housing can be generally tubular. The inner housing can have an open end at the air outlet and a closed end opposite the open end. Advantageously, the closed end can retain the aerosol-forming substrate.

[0029] At least one liquid absorbent element can be retained in the closed end of the inner housing. Advantageously, this configuration prevents liquid droplets from exiting the cartridge. The at least one liquid absorbent element can be retained in a recess formed by the closed end of the inner housing.

[0030] One or more air inlet openings can be provided in the wall of the inner housing between the open end and the closed end. The one or more air inlet openings can allow air to enter the inner housing.

[0031] The engagement surface can be formed by the closed end of the inner housing.

[0032] The inner housing can comprise a reservoir sealing flange which, in an initial position, engages the outer housing to seal the liquid reservoir from the heater assembly. Movement of the inner housing from the initial position relative to the outer housing can disengage the sealing flange from the outer housing, thereby allowing liquid from the liquid reservoir to pass to the heater assembly. Advantageously, this configuration keeps the aerosol-forming substrate in the reservoir when the cartridge is not in use. The sealing flange can also prevent oxidation of the aerosol-forming substrate by sealing the aerosol-forming substrate from ambient air, thus extending the shelf life of the cartridge.

[0033] The sealing flange can define an outer portion of the inner housing. The sealing flange can be provided as a sealing lip. The sealing lip can comprise a hooked profile.

[0034] The at least one liquid absorbent element can comprise an outer liquid absorbent element positioned in a portion of the airflow passage between the inner housing and the outer housing. Advantageously, this can provide additional means for absorbing liquid in the event that the inner liquid absorbent element becomes saturated with liquid.

[0035] The inner housing can engage the outer housing at a sealing interface between the heater assembly and the connection end of the cartridge. The liquid space can be defined between the inner housing and the outer housing between the sealing interface and the mouth end of the cartridge. A portion of the airflow passage can be defined between the inner housing and the outer housing between the sealing interface and the connection end of the cartridge. Advantageously, the sealing interface ensures that liquid from the reservoir passes to the heater assembly and prevents liquid passing to the connection end of the cartridge. The sealing interface can be such that a seal is maintained between the inner housing and the outer housing even when the inner housing is moved relative to the outer housing in the longitudinal direction.

[0036] The sealing interface can comprise a sealing element, such as an O-ring, which is fixed to or as part of the inner housing or the outer housing. The inner housing can comprise a guide member which holds the O-ring in place. The O-ring can exhibit a compression ratio of between 15% and 25%, preferably between 18% and 22%, more preferably about 20% when the inner housing is in the initial configuration.

[0037] The cartridge can comprise a further liquid absorbing element within the inner housing. The further liquid absorbing element can be located at the air outlet end of the airflow pathway. The further liquid absorbing element can be located upstream of the heater assembly. Advantageously, the further liquid absorbing element can act as a temporary reservoir for unvaporised liquid aerosol- forming substrate droplets that pass through the heater assembly after activation. These droplets are then absorbed by the further liquid absorbing element so that they do not flow out of the air outlet and potentially into a user's mouth.

[0038] The cartridge can comprise a porous member between the liquid reservoir and the heater assembly. The porous member can be fluid permeable. The porous member can be arranged to allow migration of aerosol-forming substrate from the liquid reservoir to the heater assembly. The porous member can limit the rate of flow of liquid aerosol-forming substrate from the liquid reservoir to the heater assembly.

[0039] The porous member can be positioned between the inner housing and the outer housing of the cartridge.

[0040] The porous member can comprise an open cell foam material.

[0041] The at least one heating element can be a susceptor element configured to be inductively heated. Advantageously, inductive heating allows for a wireless coupling between the susceptor element arranged within the cartridge and the aerosol-generating device configured to receive the cartridge. In this way, the liquid aerosol-forming substrate contained in the reservoir in the cartridge can remain sealed from any electrical connections during the shelf life period and also in operation when coupled to the aerosol-generating device.

[0042] As used herein, "susceptor element" means an element that can be heated by penetration of a varying magnetic field. Susceptor elements are typically heatable by at least one of Joule heating and magnetic hysteresis losses that are generated by inducing eddy currents in the susceptor element.

[0043] The susceptor element can comprise a susceptor material. The susceptor material can be any material capable of inductive heating to a temperature sufficient to aerosolise the aerosol-forming substrate. The following examples and features in relation to susceptors can apply to the susceptor element of the cartridge. Suitable materials for the susceptor material include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminium, nickel, nickel-containing compounds, titanium, and composites of metallic materials. Preferred susceptor materials include metals or carbon. Advantageously, the susceptor material can comprise or consist of a ferromagnetic or ferrimagnetic material (e.g. ferritic iron), a ferromagnetic alloy (such as a ferromagnetic steel or stainless steel, ferromagnetic particles and ferrite), or a composite of these. Suitable susceptor materials can be aluminium or include aluminium. The susceptor material can include greater than 5%, preferably greater than 20%, more preferably greater than 50%, or greater than 90% of a ferromagnetic, ferrimagnetic or paramagnetic material. Preferred susceptor materials can be heated to temperatures in excess of 250 degrees Celsius without degrading.

[0044] The receptor element can be formed from a single material layer. The single material layer can be a steel layer.

[0045] The receptor element can be substantially flat. "Substantially flat" can be defined as the receptor element comprising a width and height both significantly greater than its depth. The receptor element can comprise a single layer of receptor material. The receptor element can comprise two or more layers of receptor material.

[0046] The heater assembly can be a flat heater assembly. The heater assembly can be a tubular assembly.

[0047] The heating element can be a grid heating element. The grid heating element can be configured to wick liquid. A grid sensor element can eliminate the need for a separate wicking element. Either the grid heating element or the grid sensor element can provide more efficient evaporation of the liquid aerosol forming matrix. Advantageously, this can reduce manufacturing complexity and cost.

[0048] The heater assembly may include a wicking material. In addition to the heating element, a wicking material may be provided. The wicking material may be configured to wick a liquid aerosol forming matrix across the heater element. The wicking material may be provided as a wicking material layer parallel to the heating element. Multiple wicking material layers may be provided. The heating element may be disposed between the multiple wicking material layers. The wicking material may include cotton, glass fiber, or porous ceramic.

[0049] The container may include a nicotine-containing liquid. The liquid aerosol forming matrix may contain nicotine. The nicotine-containing liquid aerosol forming matrix may be a nicotine salt matrix. The liquid aerosol forming matrix may contain plant-based material. The liquid aerosol forming matrix may contain tobacco. The liquid aerosol forming matrix may contain tobacco-containing material containing volatile tobacco flavor compounds, which are released from the aerosol forming matrix upon heating. The liquid aerosol forming matrix may contain homogenized tobacco material. The liquid aerosol forming matrix may contain tobacco-free material. The liquid aerosol forming matrix may contain homogenized plant-based material.

[0050] The liquid aerosol-forming substrate can comprise one or more aerosol formers. An aerosol former is any suitable known compound or mixture of compounds which, in use, facilitates the formation of a dense and stable aerosol and is substantially resistant to thermal degradation at the operating temperature of the system. Examples of suitable aerosol formers include glycerol and propylene glycol. 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 glycerol; esters of polyhydric alcohols such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or poly-carboxylic acids such as dimethyl dodecanedioate and dimethyl tetradecanedioate. The liquid aerosol-forming substrate can comprise water, a solvent, ethanol, a botanical extract and a natural or artificial flavourant. The liquid aerosol-forming substrate can comprise nicotine and at least one aerosol former. The aerosol former can be glycerol or propylene glycol. The aerosol former can comprise both glycerol and propylene glycol. The liquid aerosol-forming substrate can have a nicotine concentration of between about 0.5% to about 10%, for example about 2%.

[0051] The inner shell and the outer shell can comprise any suitable material or combination of materials. Examples of suitable materials include a metal, an alloy, a plastic or a composite material containing one or more of those materials, or a thermoplastic suitable for use in food or pharmaceutical applications, for example polypropylene, polyether ether ketone (PEEK) and polyethylene. Preferably, the material is lightweight and non-brittle.

[0052] The cartridge can comprise an identification element at the mouth end. The identification element can identify the type of aerosol-forming substrate within the cartridge. The identification element can be secured to the outer shell.

[0053] According to a second aspect of the disclosure, there is provided a cartridge for an aerosol-generating system. The cartridge can comprise an airflow passage extending through the cartridge from an air inlet to an air outlet. The cartridge can comprise a shell. The shell can comprise an inner shell and an outer shell. At least a portion of the airflow passage can be within the inner shell. The cartridge can comprise a liquid reservoir defined between the outer shell and the inner shell. The cartridge can comprise a heater assembly extending into or across the airflow passage. The heater assembly can comprise a heating element. The heater assembly can be configured to wick liquid from the liquid reservoir across the heating element. The liquid reservoir can be sealed from the heater assembly. The inner shell can comprise an engagement surface. The inner shell can be configured to move relative to the outer shell to unseal the liquid reservoir and allow liquid from the reservoir to pass to the heater assembly when the engagement surface is urged towards the liquid reservoir.

[0054] In one embodiment according to the present aspect, there is provided a cartridge for an aerosol-generating system. The cartridge comprises an airflow pathway extending through the cartridge from an air inlet to an air outlet; a housing comprising an outer housing and an inner housing, at least a portion of the airflow pathway being within the inner housing; a liquid reservoir defined between the outer housing and the inner housing; a heater assembly extending into or across the airflow pathway, the heater assembly comprising a heating element and being configured to wick liquid from the liquid reservoir across the heating element, wherein the liquid reservoir is sealed apart from the heater assembly, wherein the inner housing comprises an engagement surface, wherein the inner housing is configured to move relative to the outer housing when the engagement surface is pushed towards the liquid reservoir to unseal the liquid reservoir and allow liquid from the reservoir to pass to the heater assembly. Advantageously, this configuration prevents accidental unsealing of the cartridge, only a portion of the engagement surface can be accessed and pushed. The cartridge can be less likely to unseal in packaging or in a user’s pocket.

[0055] The sealed configuration of the reservoir can be a pre-use configuration of the cartridge. Prior to use, the aerosol-forming substrate can be securely held in the cartridge if the cartridge is in the sealed configuration. In the sealed configuration, the aerosol-forming substrate can be sealed apart from the external environment and, in particular, protected from contact with oxygen and moisture. This can allow for a longer shelf life of the cartridge.

[0056] Preferably, the air outlet is at a mouth end of the cartridge and the connection end is opposite the mouth end. The connection end can be connectable to a device comprising a power source. The cartridge and the device can together form an aerosol-generating system. In the system, the device and the cartridge cooperate to generate an inhalable aerosol.

[0057] The cartridge can comprise a mouthpiece through which a user draws air in use. The mouthpiece can be positioned at the mouth end of the cartridge. The mouth end of the housing can comprise the mouthpiece. The mouthpiece can be integrally formed with the housing. The mouthpiece can be separately formed from the housing and connected to the housing. The mouthpiece can be connected to the housing by an interference fit. The mouthpiece can be connected to the housing by an adhesive.

[0058] The cartridge can comprise a longitudinal axis extending between the mouth end and the connection end of the cartridge. The mouth end can also be referred to as a proximal end of the cartridge and the connection end can also be referred to as a distal end of the cartridge.

[0059] The airflow pathway can extend from the air inlet at the connection end to the air outlet at the mouth end.

[0060] The cartridge can comprise at least one liquid absorption element within the airflow pathway. The at least one liquid absorption element can comprise one or more honeycomb-like porous members. Advantageously, the one or more porous members are capable of retaining liquid. This is beneficial such that the at least one liquid absorption element acts to absorb and retain aerosol-forming substrate that has migrated into the airflow pathway.

[0061] The at least one liquid absorption element can comprise a sponge material. The at least one liquid absorption element can comprise a foam material.

[0062] The at least one liquid absorption element can be retained in a recess defined in the inner housing. The recess can have an open end facing the air outlet end and a closed end opposite the open end. The closed end ensures that the liquid absorption element is securely retained in the airflow pathway and reduces the likelihood of liquid escaping. The closed end can also provide an engagement surface.

[0063] The at least one liquid absorption element can comprise an internal liquid absorption element, wherein the internal liquid absorption element is retained in a recess defined in the inner housing. Advantageously, the internal liquid absorption element acts as a reservoir for aerosol-forming substrate droplets that exit the heater assembly. Aerosol-forming substrate that is not vaporised is less likely to exit the airflow pathway through the mouthpiece or through the connection end if it is retained in the internal liquid absorption element. The internal liquid absorption element can comprise a sponge material. The internal liquid absorption element can comprise a foam material.

[0064] The outer housing can at least partially, and preferably completely, define the inner housing.

[0065] The heater assembly can be supported in the inner housing. The heater assembly can extend into or across the airflow pathway within the inner housing. Advantageously, this arrangement allows air to flow past the heater assembly (at the time of its use), so that vaporised aerosol-forming substrate is entrained in the airflow and condenses to form an aerosol. This arrangement can allow a large surface area of the heater to be exposed to the airflow, allowing a large amount of aerosol to be generated in a small cartridge.

[0066] The engagement surface can be located on the distal end of the cartridge. The engagement surface can be defined by the outer housing. The engagement surface can only be accessible through the connection end of the outer housing. Advantageously, this means that the reservoir can be more likely to remain sealed when the cartridge is not in use, as the engagement surface is only accessible from a single direction and through a single aperture in the outer housing. This means that the cartridge is less likely to accidentally unseal when not in use, for example in a user’s pocket or during transportation.

[0067] The inner housing can be generally tubular. The inner housing can have an open end at the air outlet and a closed end opposite the open end. Advantageously, the closed end can retain aerosol-forming substrate.

[0068] At least one liquid absorbing element can be held in the closed end of the inner housing. Advantageously, this configuration prevents liquid droplets from exiting the cartridge. The at least one liquid absorbing element can be held in a recess formed by the closed end of the inner housing.

[0069] One or more air inlet openings can be provided in the wall of the inner housing between the open end and the closed end. The one or more air inlet openings can allow air to enter the inner housing.

[0070] The engagement surface can be formed by the closed end of the inner housing.

[0071] The inner housing can comprise a reservoir sealing flange which, in an initial position, engages the outer housing to seal the liquid reservoir from the heater assembly. Movement of the inner housing from the initial position relative to the outer housing can cause the sealing flange to disengage from the outer housing, thereby allowing liquid from the liquid reservoir to pass to the heater assembly. Advantageously, this configuration maintains the aerosol-forming substrate in the reservoir when the cartridge is not in use. The sealing flange can also prevent oxidation of the aerosol-forming substrate by sealing the aerosol-forming substrate from ambient air, thus extending the shelf life of the cartridge.

[0072] The sealing flange can define an outer portion of the inner housing. The sealing flange can be provided as a sealing lip. The sealing lip can comprise a hook-like profile.

[0073] The at least one liquid absorbing element can comprise an outer liquid absorbing element positioned in a portion of the airflow passage between the inner housing and the outer housing. Advantageously, this can provide additional means for absorbing liquid in the event that the inner liquid absorbing element becomes saturated with liquid. The reservoir can be defined between a first portion of the outer housing and a first portion of the inner housing. The portion of the airflow passage containing the outer liquid absorbing element can be defined between a second portion of the outer housing and a second portion of the inner housing.

[0074] The inner housing can engage the outer housing at a sealing interface between the heater assembly and the connection end of the cartridge. A liquid space can be defined between the inner housing and the outer housing between the sealing interface and the mouth end of the cartridge. A portion of the airflow passage can be defined between the inner housing and the outer housing between the sealing interface and the connection end of the cartridge. Advantageously, the sealing interface ensures that liquid from the reservoir passes to the heater assembly and prevents liquid from passing to the connection end of the cartridge. The sealing interface can be such that a seal is maintained between the inner housing and the outer housing even when the inner housing is moved relative to the outer housing in the longitudinal direction.

[0075] The sealing interface can comprise a sealing element, such as an O-ring, which is secured to or as part of the inner or outer housing. The inner housing can comprise a guide member which holds the O-ring in place. The O-ring can exhibit a compression ratio of between 15% and 25%, preferably between 18% and 22%, more preferably about 20% when the inner housing is in the initial configuration.

[0076] The cartridge can comprise a further liquid absorbent element within the inner housing. The further liquid absorbent element can be located at the air outlet end of the airflow pathway. The further liquid absorbent element can be located upstream of the heater assembly. Advantageously, the further liquid absorbent element can act as a temporary reservoir for unvaporised liquid aerosol- forming substrate droplets which pass through the heater assembly after activation. These droplets are then absorbed by the further liquid absorbent element so that they do not flow out of the air outlet and potentially into the user's mouth.

[0077] The cartridge can comprise a porous member between the liquid reservoir and the heater assembly. The porous member can be fluid permeable. The porous member can be arranged to allow migration of aerosol-forming substrate from the liquid reservoir to the heater assembly. The porous member can limit the rate of flow of liquid aerosol-forming substrate from the liquid reservoir to the heater assembly. For example, the increase in temperature and pressure differential between the liquid reservoir and the external environment caused by activation of the heater assembly can cause an undesirable increase in the flow rate of liquid from the liquid reservoir. The porous member can control the flow rate by acting as a buffer to reduce the flow rate of aerosol-forming substrate to the heater assembly.

[0078] The porous member can be positioned between the inner and outer housing of the cartridge.

[0079] The porous member can comprise an open cell foam material.

[0080] The at least one heating element can be a susceptor element configured to be inductively heated. Advantageously, inductive heating allows for a wireless coupling between the susceptor element arranged within the cartridge and an aerosol-generating device configured to receive the cartridge. In this way, the liquid aerosol-forming substrate contained in the reservoir in the cartridge can remain sealed from any electrical connections during the shelf life period and also in operation when coupled to the aerosol-generating device.

[0081] The susceptor element can comprise a susceptor material. The susceptor material can be any material capable of inductively heating to a temperature sufficient to aerosolise an aerosol-forming substrate. The following examples and features in relation to the susceptor can apply to the susceptor element of the cartridge. Suitable materials for the susceptor material include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminium, nickel, nickel-containing compounds, titanium, and composites of metallic materials. Preferred susceptor materials include metals or carbon. Advantageously, the susceptor material can comprise or consist of a ferromagnetic or ferrimagnetic material (e.g. ferritic iron), a ferromagnetic alloy (such as a ferromagnetic steel or stainless steel, a ferromagnetic particle and ferrite), or a composite of these. Suitable susceptor materials can be aluminium or include aluminium. The susceptor material can include greater than 5%, preferably greater than 20%, more preferably greater than 50%, or greater than 90% of a ferromagnetic, ferrimagnetic or paramagnetic material. Preferred susceptor materials can be heated to temperatures in excess of 250 degrees Celsius without degrading.

[0082] The susceptor element can be formed from a single layer of material. The single layer of material can be a layer of steel.

[0083] The susceptor element can be substantially flat. Substantially flat can be defined as the susceptor element comprising a width and a height both much greater than a depth. The susceptor element can comprise a single layer of susceptor material. The susceptor element can comprise two or more layers of susceptor material.

[0084] The heater assembly can be a flat heater assembly. The heater assembly can be a tubular assembly.

[0085] The heating element can be a mesh heating element. The mesh heating element can be configured to wick liquid. The mesh susceptor element can obviate the need for a separate wicking element. The mesh heating element or mesh susceptor element can provide more efficient evaporation of liquid aerosol-forming substrate. Advantageously, this can reduce manufacturing complexity and cost.

[0086] The heater assembly can comprise a wicking material. The wicking material can be provided in addition to the heating element. The wicking material can be configured to wick liquid aerosol-forming substrate across the heating element. The wicking material can be provided as a layer of wicking material parallel to the heating element. The wicking material can be provided as a plurality of layers of wicking material. The heating element can be provided between the plurality of layers of wicking material. The wicking material can comprise cotton or glass fibre or a porous ceramic.

[0087] The cartridge can comprise a liquid containing nicotine. The liquid aerosol-forming substrate can comprise nicotine. The liquid aerosol-forming substrate can be a nicotine salt substrate. The liquid aerosol-forming substrate can comprise plant-based material. The liquid aerosol-forming substrate can comprise tobacco. The liquid aerosol-forming substrate can comprise tobacco-containing material containing volatile tobacco flavour compounds which are released from the aerosol-forming substrate on heating. The liquid aerosol-forming substrate can comprise homogenised tobacco material. The liquid aerosol-forming substrate can comprise tobacco-free material. The liquid aerosol-forming substrate can comprise homogenised plant-based material.

[0088] The liquid aerosol-forming substrate can comprise one or more aerosol formers. An aerosol former is any suitable known compound or mixture of compounds which, in use, facilitates the formation of a dense and stable aerosol and is substantially resistant to thermal degradation at the operating temperature of the system. Examples of suitable aerosol formers include glycerol and propylene glycol. 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 glycerol; esters of polyhydric alcohols such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or poly-carboxylic acids such as dimethyl dodecanedioate and dimethyl tetradecanedioate. The liquid aerosol-forming substrate can comprise water, a solvent, ethanol, a plant extract and a natural or artificial flavourant. The liquid aerosol-forming substrate can comprise nicotine and at least one aerosol former. The aerosol former can be glycerol or propylene glycol. The aerosol former can comprise both glycerol and propylene glycol. The liquid aerosol-forming substrate can have a nicotine concentration of between about 0.5% to about 10%, for example about 2%.

[0089] The inner housing and the outer housing can comprise any suitable material or combination of materials. Examples of suitable materials include a metal, an alloy, a plastic or a composite material containing one or more of those materials, or a thermoplastic suitable for use in food or pharmaceutical applications, for example polypropylene, polyether ether ketone (PEEK) and polyethylene. Preferably, the material is lightweight and non-brittle.

[0090] The cartridge can comprise an identification element at the mouth end. The identification element can identify the type of aerosol-forming substrate within the cartridge. The identification element can be secured to the outer housing.

[0091] According to a third aspect of the disclosure, there is provided an aerosol-generating system comprising a cartridge according to the first or second embodiments of the disclosure, and a device, the device comprising a power supply.

[0092] The system can be configured such that the inner housing is moved from an initial position as a result of the cartridge being coupled to the device. Advantageously, this configuration can cause the cartridge to remain in a sealed state when the aerosol-generating system is not in use, in which the liquid aerosol-forming substrate does not leak from the reservoir.

[0093] The device can comprise a contact surface which engages an engagement surface on the inner housing when the cartridge is coupled to the device to urge the engagement surface towards the liquid reservoir. Advantageously, this increases the likelihood of the aerosol-forming substrate leaving the liquid reservoir when the device is in use. This configuration can prevent the cartridge from leaking in a user's pocket or packaging when the engagement surface is moved by the contact surface of the device.

[0094] The aerosol-generating system can comprise a mechanical engagement mechanism between the cartridge and the device, such as a snap-fit mechanism, a screw-fit mechanism or a push-fit mechanism. The engagement mechanism is advantageous so that the cartridge and the device remain in contact with each other when the aerosol-generating system is in use. This configuration can allow for a consistent power supply to the cartridge.

[0095] The device can comprise one or more inductor coils configured to generate a variable magnetic flux through the heating element. Advantageously, heating the heating element in this way can be more efficient than other forms of heating, such as resistive heating.

[0096] At least one of the inductor coils can be a planar inductor coil and the heating element can be planar and arranged parallel to the inductor coil.

[0097] The device can comprise a cavity configured to receive at least the connection end of the cartridge. The cavity can be tubular in shape. The cavity can have a simple shape which readily receives at least the connection end of the cartridge.

[0098] The aerosol-generating system can be a hand-held aerosol-generating system. The aerosol-generating system can be a hand-held aerosol-generating system configured to allow a user to draw on a mouthpiece to draw aerosol through the first air outlet. The aerosol-generating system can have a size comparable to a conventional cigar or cigarette. The aerosol-generating system can have a total length of between about 25 mm and about 150 mm. The aerosol-generating system can have an outer diameter of between about 5 mm and about 30 mm.

[0099] The power source can be a DC power source. The power source can be a battery. The battery can be a lithium-based battery, such as a lithium-cobalt battery, a lithium-iron-phosphate battery, a lithium-titanate battery or a lithium-polymer battery. The battery can be a nickel-metal-hydride battery or a nickel-cadmium battery. The power source can be another form of charge storage device, such as a capacitor.

[0100] The heater assembly can include one or more inductor elements. When supplied with a varying current, the inductor elements can generate a varying magnetic field. The one or more inductor elements can be configured to generate a variable magnetic flux through the susceptor element. The device can include one or more inductor elements. The one or more inductor elements can be configured to generate a varying magnetic field within the device cavity. The one or more inductor elements can be disposed outside the device cavity. The one or more inductor elements can be arranged at least partially around the cavity. The one or more inductor elements can at least partially surround the susceptor element when the cartridge is coupled to the aerosol-generating device. The one or more inductor elements can be inductor coils. The inductor coils can be helical coils.

[0101] As used herein, "varying current" refers to a current that varies over time. When supplied with a varying current, the inductor elements can generate a varying magnetic field. The term "varying current" is intended to include alternating current. Where the varying current is alternating current, the alternating current produces an alternating magnetic field. The varying current can be alternating current.

[0102] As used herein, "alternating current" refers to a current that periodically changes direction. The alternating current can have any suitable frequency. Suitable frequencies for the alternating current can be between 100 kilohertz (kHz) and 30 megahertz (MHz).

[0103] The inductor elements can be formed from any suitable material. The inductor elements can be formed from at least one of silver, gold, aluminum, brass, zinc, iron, nickel, and alloys thereof, and electrically conductive ceramics such as yttrium-doped zirconia, indium tin oxide, and yttrium-doped titanate.

[0104] The aerosol-generating system can be a handheld aerosol-generating system configured to allow a user to draw on a mouthpiece to draw aerosol through the mouth end opening. The aerosol-generating system can have a size comparable to a conventional cigar or cigarette. The aerosol-generating system can have an overall length of between about 30 millimeters and about 150 millimeters. The aerosol-generating system can have an outer diameter of between about 5 millimeters to about 30 millimeters.

[0105] The aerosol-generating system can be configured to deliver nicotine or the like to a user. The aerosol-generating system can be an electrically operated smoking device.

[0106] The control circuitry can comprise a microprocessor. The microprocessor can be a programmable microprocessor, a microcontroller, or an application specific integrated chip (ASIC) or other circuitry capable of providing control. The control circuitry can be configured to continuously supply power to the at least one inductor coil after the device is activated, or can be configured to supply power intermittently, such as on a puff-by-puff basis. The power can be supplied in the form of current pulses, for example by means of pulse width modulation (PWM) to the inductive heating assembly. The control circuitry can comprise a DC / AC inverter, which can comprise a class-D or class-E power amplifier. The control circuitry can comprise further electronic components. For example, in some embodiments, the control circuitry can comprise any of a sensor, a switch, a display element.

[0107] It will be appreciated that any features described herein in relation to one embodiment of a cartridge or aerosol-generating system can also apply to other embodiments of cartridges and aerosol-generating systems according to the disclosure. Features described in relation to one embodiment can equally apply to another embodiment according to the disclosure. It will also be appreciated that aerosol-generating systems according to the disclosure can be provided in an aerosol-generating device without a cartridge. Thus, any of the features described herein in relation to a cartridge can equally apply to an aerosol-generating device.

[0108] The application is defined in the claims. However, a non-exhaustive list of non-limiting examples is provided below. Any one or more features of these examples can be combined with any one or more features of another example, embodiment, or aspect described herein.

[0109] Ex1. A cartridge for an aerosol-generating system, the cartridge comprising: a housing defining an airflow pathway from an air inlet to an air outlet; a liquid reservoir within the housing; at least one liquid absorbent element in fluid communication with, and preferably within, the airflow pathway; and a heater assembly extending into or across the airflow pathway, the heater assembly comprising a heating element and being configured to wick liquid from the liquid reservoir across the heating element, the heater assembly is positioned in the airflow pathway between the at least one liquid absorbent element and the air outlet.

[0110] Ex2. The cartridge according to example Ex1, wherein the air outlet is at a mouth end of the cartridge and a connection end of the cartridge is opposite the mouth end, and wherein the at least one liquid absorbent element is positioned between the heater assembly and the connection end.

[0111] Ex3. A cartridge according to example Ex2, wherein the mouth end of the housing comprises a mouthpiece through which a user draws air in use.

[0112] Ex4. A cartridge according to example Ex1 or Ex2, wherein the cartridge comprises a longitudinal axis extending between a mouth end (also referred to as a proximal end) and a connection end (also referred to as a distal end) of the cartridge.

[0113] Ex5. A cartridge according to example Ex2, Ex3 or Ex4, wherein the airflow pathway extends from an air inlet at the connection end to an air outlet at the mouth end.

[0114] Ex6. A cartridge according to any one of examples Ex2 to Ex5, wherein the connection end is configured to connect to a device comprising a power supply.

[0115] Ex7. A cartridge according to any one of the preceding examples, wherein the at least one liquid absorbent element comprises one or more open-pored porous members.

[0116] Ex8. A cartridge according to any one of the preceding examples, wherein the liquid absorbent element is held in a recess defined in the housing, and wherein the recess has an open end facing the air outlet end and a closed end opposite the open end.

[0117] Ex9. A cartridge according to any one of the preceding examples, wherein the housing comprises an outer housing and an inner housing, at least a portion of the airflow pathway is within the inner housing, and the reservoir is defined between the outer and inner housings.

[0118] Ex10. A cartridge according to example Ex9, wherein the at least one liquid absorbent element comprises an inner liquid absorbent element, wherein the inner liquid absorbent element is held in a recess defined in the inner housing.

[0119] Ex11. A cartridge according to example Ex9 or Ex10, wherein the outer housing at least partially, and preferably completely, defines the inner housing.

[0120] Ex12. A cartridge according to example Ex9, Ex10 or Ex11, wherein the heater assembly is supported in the inner housing.

[0121] Ex13. A cartridge according to any one of examples Ex9 to Ex12, wherein the heater assembly extends into or across the airflow pathway within the inner housing.

[0122] Ex14. The cartridge according to any one of Examples Ex9 to Ex13, wherein in an initial configuration the liquid reservoir is sealed off from the heater assembly, and wherein the inner housing is configured to move relative to the outer housing to unseal the liquid reservoir and thereby allow liquid from the liquid reservoir to pass to the heater assembly.

[0123] Ex15. The cartridge according to Example Ex14, wherein the inner housing has an engagement surface, wherein the engagement surface of the inner housing is accessible from the exterior of the cartridge to allow the inner housing to move out of the initial position.

[0124] Ex16. The cartridge according to Example Ex15, wherein the engagement surface is defined by the outer housing, preferably such that the engagement surface is only accessible through a connection end of the outer housing.

[0125] Ex17. The cartridge according to any one of Examples Ex9 to Ex16, wherein the inner housing is generally tubular and has an open end at the air outlet and a closed end opposite the open end.

[0126] Ex18. The cartridge according to Example Ex17, wherein the liquid absorbent element is held in the closed end of the inner housing.

[0127] Ex19. The cartridge according to Example Ex17 or Ex18, wherein one or more air inlet openings are provided in a wall of the inner housing between the open end and the closed end.

[0128] Ex20. The cartridge according to Example Ex17, Ex18 or Ex19, wherein the engagement surface of Example Ex15 is formed by the closed end of the inner housing.

[0129] Ex21. The cartridge according to Example Ex20, wherein the liquid absorbent element is held in a recess formed by the closed end of the inner housing.

[0130] Ex22. The cartridge according to any one of Examples Ex9 to Ex21, wherein the inner housing comprises a reservoir sealing flange that in an initial position engages the outer housing to seal off the liquid reservoir from the heater assembly, and wherein movement of the inner housing relative to the outer housing from the initial position disengages the sealing flange from the outer housing, thereby allowing liquid from the liquid reservoir to pass to the heater assembly.

[0131] Ex23. The cartridge according to any one of Examples Ex9 to Ex22, wherein the outer housing comprises the air inlet.

[0132] Ex24. A cartridge according to any one of Examples Ex9 to Ex23, wherein the at least one liquid absorbent element comprises an external liquid absorbent element positioned in a portion of the airflow passage between the inner housing and the outer housing.

[0133] Ex25. A cartridge according to any one of Examples Ex9 to Ex24, wherein the inner housing engages the outer housing at a sealing interface between the heater assembly and the connection end of the cartridge, such that a liquid space is defined between the inner housing and the outer housing between the sealing interface and the mouth end of the cartridge, and a portion of the airflow passage is defined between the inner housing and the outer housing between the sealing interface and the connection end of the cartridge.

[0134] Ex26. A cartridge according to Example Ex25, wherein the sealing interface comprises a sealing element, such as an O-ring, secured to the inner housing or as part of the inner housing.

[0135] Ex27. A cartridge according to any one of the preceding Examples, comprising a further liquid absorbent element within the inner housing.

[0136] Ex28. A cartridge according to Example Ex27, wherein the further liquid absorbent element is located at the air outlet end of the airflow passage.

[0137] Ex29. A cartridge according to any one of the preceding Examples, further comprising a porous member between the liquid reservoir and the heater assembly.

[0138] Ex30. A cartridge according to Example Ex29, wherein the porous member is positioned between the inner and outer housings of the cartridge.

[0139] Ex31. A cartridge according to Example Ex29 or Ex30, wherein the porous member comprises an open cell foam material.

[0140] Ex32. A cartridge according to any one of the preceding Examples, wherein the heating element is a susceptor element.

[0141] Ex33. A cartridge according to any one of the preceding Examples, wherein the heater assembly is a flat heater assembly or a tubular heater assembly.

[0142] Ex34. A cartridge according to any preceding Example, wherein the heating element is a mesh heating element configured to wick liquid.

[0143] Ex35. A cartridge according to any preceding Example, comprising a liquid containing nicotine.

[0144] Ex36. A cartridge for use in an aerosol-generating system, the cartridge comprising: an airflow pathway extending through the cartridge from an air inlet to an air outlet, a housing comprising an outer housing and an inner housing, at least a portion of the airflow pathway being within the inner housing, a liquid reservoir defined between the outer and inner housings, a heater assembly extending into or across the airflow pathway, the heater assembly comprising a heating element and being configured to wick liquid from the liquid reservoir across the heating element, wherein the liquid reservoir is sealed from the heater assembly, wherein the inner housing comprises an engagement surface, wherein the inner housing is configured to move relative to the outer housing when the engagement surface is urged towards the liquid reservoir to unseal the liquid reservoir and allow liquid from the reservoir to pass to the heater assembly; and wherein the outer housing surrounds the engagement surface of the inner housing and defines an engagement opening through which the engagement surface is accessible to urge the engagement surface towards the liquid reservoir.

[0145] Ex37. The cartridge according to example Ex36, wherein the air outlet is at a mouth end of the cartridge and the connection end is opposite the mouth end.

[0146] Ex38. The cartridge according to example Ex37, wherein the mouth end of the housing comprises a mouthpiece through which a user draws air in use.

[0147] Ex39. The cartridge according to example Ex37 or Ex38, wherein the cartridge comprises a longitudinal axis extending between a mouth end (also referred to as a proximal end) and a connection end (also referred to as a distal end) of the cartridge.

[0148] Ex40. The cartridge according to any one of examples Ex37 to Ex39, wherein the connection end is configured to connect to a device comprising a power source.

[0149] Ex41. The cartridge according to any one of examples Ex37 to Ex40, comprising at least one liquid absorbent element in fluid communication with, and preferably within, the airflow pathway, and wherein the at least one liquid absorbent element is positioned between the heater assembly and the connection end.

[0150] Ex42. The cartridge according to example Ex41, wherein the at least one liquid absorbent element comprises one or more open-pored porous members.

[0151] Ex43. The cartridge according to Example Ex41 or Ex42, wherein the liquid absorbing element is held in a recess defined in the housing, and wherein the recess has an open end facing the air outlet end and a closed end opposite the open end.

[0152] Ex44. The cartridge according to Example Ex41, Ex42, or Ex43, wherein the at least one liquid absorbing element comprises an inner liquid absorbing element, wherein the inner liquid absorbing element is held in a recess defined in the inner housing.

[0153] Ex45. The cartridge according to any one of Examples Ex36 to Ex44, wherein the outer housing at least partially, and preferably completely, defines the inner housing.

[0154] Ex46. The cartridge according to any one of Examples Ex36 to Ex45, wherein the heater assembly is supported in the inner housing.

[0155] Ex47. The cartridge according to any one of Examples Ex36 to Ex46, wherein the heater assembly extends into or across an airflow passage within the inner housing.

[0156] Ex48. The cartridge according to any one of Examples Ex36 to Ex47, wherein the inner housing is generally tubular and has an open end at the air outlet and a closed end opposite the open end.

[0157] Ex49. The cartridge according to Example Ex48, wherein the liquid absorbing element of Example Ex41 is held in the closed end of the inner housing.

[0158] Ex50. The cartridge according to Example Ex48 or Ex49, wherein one or more air inlet openings are provided in a wall of the inner housing between the open end and the closed end.

[0159] Ex51. The cartridge according to Example Ex48, Ex49, or Ex50, wherein the engagement surface is formed by the closed end of the inner housing.

[0160] Ex52. The cartridge according to Example Ex51, wherein the liquid absorbing element of Example Ex41 is held in a recess formed by the closed end of the inner housing.

[0161] Ex53. The cartridge of any of Examples Ex36 to Ex52, wherein the inner housing includes a reservoir sealing flange that engages the outer housing in an initial position to seal the liquid reservoir apart from the heater assembly, and wherein movement of the inner housing relative to the outer housing from the initial position disengages the sealing flange from the outer housing, thereby allowing liquid from the liquid reservoir to pass to the heater assembly.

[0162] Ex54. The cartridge of any of Examples Ex35 to Ex53, wherein the outer housing includes the air inlet.

[0163] Ex55. The cartridge of any of Examples Ex41 to Ex54, wherein the at least one liquid absorbing element includes an external liquid absorbing element positioned in a portion of the airflow pathway between the inner housing and the outer housing.

[0164] Ex56. The cartridge of any of Examples Ex36 to Ex55, wherein the inner housing engages the outer housing at a sealing interface between the heater assembly and the cartridge’s connection end, such that a liquid space is defined between the inner housing and the outer housing between the sealing interface and the cartridge’s mouth end, and a portion of the airflow pathway is defined between the inner housing and the outer housing between the sealing interface and the cartridge’s connection end.

[0165] Ex57. The cartridge of Example Ex56, wherein the sealing interface includes a sealing element, such as an O-ring, secured to or as part of the inner housing.

[0166] Ex58. The cartridge of any of Examples 36 to 57, including a further liquid absorbing element within the inner housing.

[0167] Ex59. The cartridge of Example Ex58, wherein the further liquid absorbing element is located at an air outlet end of the airflow pathway.

[0168] Ex60. The cartridge of any of Examples Ex36 to Ex59, further comprising a porous member between the liquid reservoir and the heater assembly.

[0169] Ex61. The cartridge of Example Ex60, wherein the porous member is positioned between the inner and outer housings of the cartridge.

[0170] Ex62. The cartridge of Example Ex60 or Ex61, wherein the porous member comprises an open cell foam material.

[0171] Ex63. A cartridge according to any one of Examples Ex36 to Ex62, wherein the heating element is a susceptor element.

[0172] Ex64. A cartridge according to any one of Examples Ex36 to Ex63, wherein the heater assembly is a flat heater assembly or a tubular heater assembly.

[0173] Ex65. A cartridge according to Examples Ex36 to Ex64, wherein the heating element is a mesh heating element configured to wick liquid.

[0174] Ex66. A cartridge according to Examples Ex36 to Ex65, comprising a nicotine-containing liquid.

[0175] Ex67. An aerosol-generating system comprising a cartridge according to any one of the preceding Examples, and a device, in use the cartridge is secured to the device, the device comprising a power source.

[0176] Ex68. An aerosol-generating system according to Example Ex67, wherein the system is configured such that the inner housing is moved from an initial position as a result of the cartridge being coupled to the device.

[0177] Ex69. An aerosol-generating system according to Example Ex68, wherein the device comprises a contact surface which engages an engagement surface on the inner housing when the cartridge is coupled to the device to urge the engagement surface towards the liquid reservoir.

[0178] Ex70. An aerosol-generating system according to Examples Ex67, Ex68 or Ex69, comprising a mechanical engagement mechanism between the cartridge and the device, such as a snap-fit mechanism, a screw-fit mechanism or a push-fit mechanism.

[0179] Ex71. An aerosol-generating system according to any one of Examples Ex67 to Ex70, wherein the device comprises one or more inductor coils configured to generate a variable magnetic flux through the heating element.

[0180] Ex72. An aerosol-generating system according to Example Ex71, wherein at least one inductor coil is a planar inductor coil and the heating element is planar and arranged parallel to the planar inductor coil.

[0181] Ex73. An aerosol-generating system according to any one of Examples Ex67 to Ex72, wherein the device comprises a cavity configured to receive at least a connection end of the cartridge.

[0182] Ex74. An aerosol-generating system according to Example EX73, wherein the reusable device comprises one or more inductor coils positioned around the cavity.

[0183] Ex75. An aerosol-generating system according to Example Ex74, wherein the one or more inductor coils comprise a helical coil around at least a portion of the cavity.

[0184] Ex76. An aerosol-generating system according to any one of Examples Ex73 to Ex75, wherein the device comprises a protrusion extending from a base of the cavity, an end face of the protrusion forming a contact surface for engaging an engagement surface of an inner housing of the cartridge.

[0185] The application will be further described, by way of example only, with reference to the accompanying drawings in which: Figure 1A is a cross-sectional schematic view of an aerosol-generating system according to the present disclosure in a sealed configuration; Figure 1B shows a cross-sectional schematic view of the aerosol-generating system of Figure 1A in a use configuration; Figure 2 is a perspective view of the cartridge shown in Figure 1A and 1B is a perspective view of an embodiment of the cartridge shown in; and Figure 3 is an exploded view of the cartridge of Figure 2

[0186] Figure 1A shows a schematic view of an aerosol-generating system according to the present disclosure, with the cartridge in a sealed configuration separated from the device. Figure 1B shows a schematic view of an aerosol-generating system in a use configuration, with the cartridge coupled to the device and in an unsealed configuration. The system 10 comprises a cartridge 50 and a device 80 configured to removably couple together to form an aerosol-generating system 10. Figure 2 and 3 shows the cartridge of the system in more detail. The aerosol-generating system is portable and has a size comparable to a conventional cigar or cigarette.

[0187] The cartridge 50 comprises a heater assembly 12 mounted in the inner housing 20. In this embodiment, the heater assembly 12 is a susceptor assembly 12. The susceptor assembly 12 is planar and in the form of a sheet, with a thickness dimension substantially smaller than a length dimension and a width dimension. The susceptor assembly 12 has a rectangular shape. In other embodiments, the susceptor assembly can have a cylindrical shape or another suitable shape. The susceptor assembly 12 is configured to be heatable by penetration by an alternating magnetic field for vaporising an aerosol-forming substrate.

[0188] ​The susceptor assembly 12 includes a susceptor element. The susceptor element includes a mesh having filaments extending in a first direction and filaments extending in a second direction that is substantially perpendicular to the first direction. The susceptor element includes AISI 410 stainless steel (ferritic stainless steel) filaments extending in both the first direction and the second direction. In other embodiments, the susceptor assembly can include a susceptor element that includes a combination of magnetic materials. For example, in some embodiments, the susceptor element includes AISI 410 stainless steel (ferritic stainless steel) filaments extending in the first direction and AISI 316 stainless steel (austenitic stainless steel) filaments extending in the second direction. The susceptor assembly 12 also includes a layer of wicking material extending parallel to the susceptor element. The wicking material is configured to wick liquid aerosol-forming substrate across the susceptor element. The wicking element includes cotton. In other embodiments, the wicking material can include glass fibers or porous ceramic. The susceptor assembly can include two susceptor elements sandwiching the layer of wicking material.

[0189] The cartridge 50 includes an outer housing 22 formed of a moldable plastic material such as polypropylene. The cartridge also includes an inner housing 20 that generally forms a hollow cylinder to define an interior space across which the susceptor assembly extends. The inner housing 20 includes an open end positioned towards the mouth end of the cartridge 50 and a closed end opposite the mouth end.

[0190] The cartridge 50 has a mouth end and a connection end opposite the mouth end. The outer housing 22 defines a mouth end opening 34 at the mouth end of the cartridge 50. The connection end is configured for connecting the cartridge 50 to the device 80. The susceptor assembly 12 is positioned towards the connection end of the cartridge 50. The outer housing 22 is wider externally at the mouth end of the cartridge 50 than at the connection end, forming a shoulder 37. This enables the connection end of the cartridge 50 to be received in the cavity 64 of the device 80 with the shoulder 37 positioning the cartridge 50 in the correct position relative to the device 80. This also enables the mouth end of the cartridge 50 to be retained outside of the device 80 with the mouth end conforming to the external shape of the device 80.

[0191] The outer housing 22 is slidable relative to the inner housing between an initial sealed configuration as shown in Figure 1A and an unsealed use configuration as shown in Figure 1B The inner housing of the cartridge is configured to move when the engagement surface 42 is acted upon by the push member. The engagement surface 42 is a portion of the outer surface of the inner housing 20 at the connection end and is configured to interact with the device 80.

[0192] The outer housing 22 includes a base housing portion 38 at the connection end of the cartridge 50. The base housing portion 38 surrounds the base of the inner housing, covering the engagement surface, but includes an opening through which the engagement surface 42 is accessible and through which the engagement surface can be pushed by the push member.

[0193] The cartridge defines a liquid reservoir 40 that holds liquid aerosol-forming substrate 46. The liquid reservoir 40 is positioned toward the mouth end of the outer housing 22 and includes an annular space defined within the outer housing 22. The reservoir surrounds the internal passageway 30 that extends between the mouth end opening 34 and the open end of the inner housing 20.

[0194] The inner housing 20 also includes a reservoir seal flange 28 that is engaged with the outer housing 22 in the sealed configuration shown to seal the liquid reservoir 40 and prevent liquid from reaching the susceptor assembly 12. In the sealed configuration, the liquid aerosol-forming substrate 46 contained within the liquid reservoir 40 is fluidically isolated by the reservoir seal flange 28. Movement of the inner housing 20 relative to the outer housing 22 disengages the reservoir seal flange 28 from the outer housing 22, allowing the liquid aerosol-forming substrate 46 to pass to the susceptor assembly 12. As the inner housing 20 moves toward the unsealed configuration, a gap 44 is created that allows liquid to exit the liquid reservoir 40. Figure 1A

[0195] The cartridge 50 includes a porous member 16 positioned between the liquid reservoir 40 and the susceptor assembly 12. The porous member 16 allows liquid aerosol-forming substrate to migrate from the liquid reservoir 40 toward the susceptor assembly 12 when the aerosol-generating system 10 is in the use configuration. Liquid from the liquid reservoir 40 passes through the porous member 16 to the susceptor assembly 12 when the aerosol-generating system 10 is in the use configuration. The porous member 16 controls the rate at which liquid can flow to the susceptor assembly 12.

[0196] The sealing interface between the inner housing 20 and the outer housing 22 is at the connection end of the cartridge 50. The sealing interface includes a sealing element 24. Figure 1A and 1B The sealing element shown in FIGS. 1-3 is an O-ring that is fixed to a portion of the inner housing 20. The O-ring engages the inner surface of the outer housing. A liquid space is defined between the inner housing 20 and the outer housing 22 on the proximal side of the sealing element 24, and a portion of the airflow passageway is defined between the inner housing 20 and the outer housing 22 on the distal side of the sealing element 24.

[0197] The cartridge 50 includes an internal liquid absorption element 36 that is held in a recess defined in the inner housing 20. The internal liquid absorption element 36 holds liquid aerosol-forming substrate that has escaped from the susceptor assembly 12 and has not yet evaporated or has condensed. The internal liquid absorption element 36 includes a sponge material.

[0198] ​The cartridge 50 also comprises an outer liquid absorbent element 26 positioned in a portion of the airflow path between the inner housing 20 and the outer housing 22. The outer liquid absorbent element 26 provides additional means for absorbing liquid aerosol-forming substrate, for example when the inner liquid absorbent element 36 becomes saturated with liquid. The outer liquid absorbent element 26 comprises a sponge material.

[0199] The device 80 comprises a generally cylindrical housing 62 having a connection end and a distal end opposite the connection end. A cavity 64 for receiving the connection end of a cartridge is located at the connection end of the device 80 and an air inlet 65 is provided through the outer housing 62 at the base of the cavity 64 to enable ambient air to be drawn into the cavity 64 at the base.

[0200] Alternatively, the air inlet can be formed at the interface between the device and the cartridge. In this arrangement, the air inlet is positioned at the open end of the cavity. Air from the air inlet then travels between the outer housing of the cartridge and the wall of the cavity to the air inlet of the cartridge.

[0201] The device 80 also comprises an induction heating arrangement arranged within the housing 62. The induction heating arrangement comprises one or more inductor coils 54 and control circuitry 70 and a power supply 72. The power supply 72 comprises a rechargeable nickel-cadmium battery which can be recharged via an electrical connector (not shown) at the distal end of the device. The control circuitry 70 is connected to the power supply 72 and the inductor coils 54 such that the control circuitry 70 controls the supply of power to the inductor coils 54. The control circuitry 70 is configured to supply an alternating current to the inductor coils 54.

[0202] When the cartridge 50 is received in the cavity 64, the susceptor assembly 12 is arranged between the inductor coils 54. A flux concentrator 56 is provided around each of the inductor coils 54 so as to contain and concentrate the magnetic field within the cavity 64. The flux concentrator can be formed from a magnetic material such as iron.

[0203] The inductor coils 54 are configured such that when an alternating current is supplied to the inductor coils 54, the inductor coils generate an alternating magnetic field in the cavity 64. The alternating magnetic field generated by each of the inductor coils 54 is oriented substantially perpendicular to the plane of the susceptor assembly 12.

[0204] When the connection end of the cartridge 50 is inserted into the cavity 64, the engagement surface 42 of the cartridge 50 contacts a contact surface 68 located at the base of the cavity 64. The contact surface 68 is rigid and configured not to move when contacted by the engagement surface 42. The contact surface 68 provides a pushing member to slide the inner housing 20 towards the mouth end such that the reservoir sealing flange 28 unseals the liquid reservoir 40, allowing the liquid aerosol-forming substrate 46 to migrate towards the susceptor assembly 12. In use configuration, the length of the gap 44 is equal to the height of the contact surface 68 above the base of the cavity 64.

[0205] In operation, as shown by the solid arrows in Figure 1B , when a user draws on the mouth end opening 34 of the cartridge 50, ambient air is drawn through the air inlet 65 into the base of the cavity 64 and into the cartridge 50. The inner housing 20 comprises an airflow management component 47 which comprises an air inlet opening 48 for air to enter. The air inlet opening is distinct from the air inlet of the cartridge provided in the outer housing. The airflow management component 47 is described in further detail below in Figures 5a, 5b and 5c. Figure 1B The dashed arrows in show the airflow within the inner housing 20. The inner housing 20 is configured to allow air to flow through the susceptor assembly 12 when the aerosol-generating system 10 is in use. The vaporised aerosol-forming substrate is then entrained in the airflow and condenses to form an aerosol.

[0206] When the system is activated, the control circuitry 70 controls the supply of power from the power source 72 to the inductor coil 54. The control circuitry can comprise an airflow sensor (not shown) and when the airflow sensor detects a user drawing on the cartridge 50, the control circuitry can supply power to the inductor coil 54. This type of control has been used for many years in aerosol-generating systems such as inhalers and e-cigarettes.

[0207] When the system 10 is activated, an alternating current is generated in the inductor coil 54 which generates an alternating magnetic field in the cavity 64 which penetrates the susceptor assembly 12, causing the susceptor element to heat up. The liquid aerosol-forming substrate 46 in the liquid reservoir 40 is drawn through the porous member 16 into the susceptor assembly 12. The aerosol-forming substrate is heated and volatile compounds from the heated aerosol-forming substrate are released into the air passageway of the inner housing 20, the volatile compounds cool to form an aerosol. The aerosol is entrained in the air drawn through the air passageway and is drawn out of the cartridge 50 at the mouth end opening 34 for the user to inhale.

[0208] Figure 2 A cartridge 50 according to embodiments of Figure 1A and 1B is shown. The outer housing is shown in cross-section but the inner housing 20 is not shown in cross-section. As will be described, the flavour indicator 88 and the mouthpiece wick 89 are also shown in cross-section, connected to the mouth end of the outer housing. Figure 2 The cartridge 50 of Figure 3 is in a use configuration. Figure 2 is an exploded view of the cartridge.

[0209] The inner housing 20 comprises two parts; a sealing component 49, which is connected to the airflow management component 47. The sealing component 49 comprises a reservoir sealing flange 28. In the sealed configuration, the reservoir sealing flange 28 engages with the outer housing 22 to fluidly isolate the liquid reservoir 40 from the susceptor assembly. The susceptor assembly 12 is held in the airflow management component 47. The outer housing 22 also comprises two parts. A base portion 38 surrounds the airflow management component 47. An O-ring 26 on the airflow management component contacts and seals the inner surface of the base portion 38. The O-ring maintains a liquid tight seal between the inner and outer housings as the inner housing moves relative to the outer housing. A mouth end portion 93 of the outer housing engages the base portion. The mouth end portion comprises an inner airflow tube which engages the sealing component of the inner housing to maintain a liquid tight seal around the airflow path.

[0210] In the use configuration shown in Figure 2 The inner housing 20 has moved relative to the outer housing 22 towards the mouth end, such that the reservoir sealing flange 28 has disengaged from the outer housing 22, leaving a gap for liquid aerosol-forming substrate in the liquid reservoir 40 to travel through. The liquid aerosol-forming substrate then migrates through the porous member 16 towards the susceptor assembly 12.

[0211] The airflow management component 47 comprises an air inlet opening 48, allowing air to enter the hollow tubular interior of the inner housing 20. The airflow management component can have more than one air inlet opening. The airflow management component comprises a first protrusion 61 and a second protrusion 63 configured to hold the O-ring sealing element 24 in place. The sealing element 24 prevents liquid aerosol-forming substrate in the liquid space from entering the airflow path directly.

[0212] The internal liquid absorption element 36 (not shown in Figure 2 but clearly seen in Figure 3 ) holds liquid aerosol-forming substrate droplets that have not evaporated or can have condensed within the airflow path away from the susceptor assembly 12. The internal liquid absorption element 36 is located within the airflow management component interior below the air inlet opening 48 so as not to obstruct airflow. The external liquid absorption element 26 is located outside the inner housing between the airflow management component 47 and the outer housing 22. The external liquid absorption element 26 is positioned in a portion of the airflow path with spaces provided between the external liquid absorption element 26 for airflow. The external liquid absorption element 26 is able to hold excess substrate droplets that pass from the internal liquid absorption element if it becomes full. The external liquid absorption element can also absorb any liquid that passes through the O-ring.

[0213] The bottom portion 38 of the outer housing 22 surrounds the engagement surface 42 of the inner housing 20 and defines an engagement opening through which the engagement surface 42 can be accessed to urge the engagement surface 42 towards the liquid reservoir 40. The engagement opening is also the air inlet for the cartridge.

[0214] The susceptor assembly 12 and the internal liquid absorbent element 36 are more clearly visible in the exploded view of Figure 3 The susceptor assembly 12 is held in a slot in the airflow management component such that the susceptor element is within the airflow passage. The wicking material extends through the slot to contact the porous element 16.

[0215] The internal liquid absorbent element 36 is placed in a recess formed by the closed end of the airflow management component. The internal liquid absorbent element 36 is positioned to capture liquid droplets that have leaked from the susceptor assembly in the inner housing and that condense within the inner housing. The position of the internal liquid absorbent element between the susceptor assembly and the connection end of the cartridge is such that during normal use, gravity will drive liquid droplets towards it.

[0216] The bottom housing 38 substantially surrounds the engagement surface 42, leaving an opening for the engagement surface 42 to engage with the contact surface 68 located within the cavity 64 of the device 80. Airflow enters through the engagement opening, passes through the outer liquid absorbent element to the air inlet opening 48. The airflow then passes through the inner housing, through the susceptor element to the mouth end.

[0217] The mouthpiece cotton disc 89 is a further liquid absorbent element provided at the mouth end of the cartridge. The mouthpiece cotton disc 89 mitigates the situation of any large liquid droplets exiting the cartridge through the mouth end.

[0218] The flavour indicator 88 is fitted above the mouthpiece cotton disc 89. The flavour indicator can be coloured or marked to indicate the flavour or type of liquid contained in the cartridge.

[0219] During manufacture, the cartridge can be filled with liquid through an opening provided in the outer housing at the mouth end. Two openings are provided, one for receiving the liquid and the other for expelling air from the liquid reservoir. As Figure 2 The mouthpiece cotton disc has a corresponding opening which is sealed by the flavour indicator after the cartridge has been filled, as shown in

Claims

1. A cylinder for an aerosol generation system, the cylinder comprising: A housing that defines an airflow path from an air inlet to an air outlet; The liquid reservoir inside the housing; At least one liquid absorption element, which is in fluid communication with the airflow passage and preferably within the airflow passage; as well as A heater assembly extending into or across the airflow passage, the heater assembly including a heating element and configured to wick liquid from the liquid reservoir across the heating element. The heater assembly is positioned in the airflow passage between the at least one liquid absorption element and the air outlet; The housing includes an outer shell and an inner shell, at least a portion of the airflow passage is within the inner shell, and the liquid reservoir is defined between the outer shell and the inner shell; The at least one liquid absorption element includes an internal liquid absorption element, wherein the internal liquid absorption element is held in a recess defined in the inner housing.

2. The cylinder of claim 1, wherein the air outlet is located at the inlet end of the cylinder and the connecting end of the cylinder is opposite to the inlet end, and wherein the at least one liquid absorption element is positioned between the heater assembly and the connecting end.

3. The cylinder according to claim 1 or claim 2, wherein the liquid absorption element is held in a recess defined in the housing, and wherein the recess has an open end facing an air outlet end and a closed end opposite to the open end.

4. The cylinder according to any of the preceding claims, wherein in an initial configuration, the liquid reservoir is sealed apart from the heater assembly, and wherein the inner housing is configured to move relative to the outer housing to unseal the liquid reservoir, thereby allowing liquid from the liquid reservoir to be transferred to the heater assembly.

5. The cylinder of claim 4, wherein the inner housing has a mating surface, wherein the mating surface of the inner housing is accessible from the outside of the cylinder to allow the inner housing to move out of its initial position.

6. The cylinder according to claim 5, wherein the mating surface is defined by the outer shell, preferably such that the mating surface is accessible only through the connecting end of the outer shell.

7. The cylinder according to any of the preceding claims, wherein the inner shell is generally tubular and has an open end at the air outlet and a closed end opposite to the open end, wherein the liquid absorption element is retained in the closed end of the inner shell.

8. The cylinder according to any of the preceding claims, wherein the at least one liquid absorption element comprises an external liquid absorption element positioned between the inner housing and the outer housing in a portion of the airflow passage.

9. The cylinder according to any of the preceding claims, comprising an additional liquid absorption element located at the air outlet end of the airflow passage.

10. The cylinder according to any one of the preceding claims, wherein the heating element is a sensor element.

11. The cylinder according to any one of the preceding claims, wherein the heating element is a mesh heating element configured to wick liquid.

12. The cylinder according to any one of the preceding claims, wherein the at least one liquid absorption element comprises one or more open-pore porous components.

13. The cylinder according to any one of the preceding claims further includes a porous member between the liquid reservoir and the heater assembly.

14. The cylinder of claim 13, wherein the porous member is positioned between the inner shell and the outer shell of the cylinder.

15. An aerosol generation system comprising a cylinder according to any of the foregoing examples, and an apparatus wherein, in use, the cylinder is fixed to the apparatus, the apparatus including a power source.

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