A cartridge for an aerosol-generating system having a liquid absorbing element

Abstract

A cartridge for an aerosol-generating system comprising: a housing, the 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 airflow passage, and a heater assembly, the heater assembly extending in or across the airflow passage, 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 passage between the at least one liquid absorbing element and the air outlet.

Description

[0001] A CARTRIDGE FOR AN AEROSOL-GENERATING SYSTEM HAVING A LIQUID ABSORBING ELEMENT

[0002] The present disclosure relates to a cartridge for an aerosol-generating system. The disclosure further relates to an aerosol-generating system comprising a cartridge and an aerosol-generating device.

[0003] It is known to provide an aerosol-generating device for generating an inhalable vapor. Such devices may heat an aerosol-forming substrate contained in a cartridge without burning the aerosolforming substrate. The aerosol-generating device may comprise a heating arrangement. The heating arrangement may be an induction heating arrangement and may comprise an induction coil and a susceptor. The susceptor may be part of the device or may be part of the cartridge.

[0004] Upon heating to a target temperature, the aerosol-forming substrate vaporises to form an aerosol. The aerosol-forming substrate may be present in solid form or in liquid form. Liquid aerosolforming substrate may be comprised in a liquid storage portion and may be delivered to the heating element via a capillary component.

[0005] Aerosol-generating devices and cartridges for use therewith may be taken by consumers wherever they go. Small size devices and cartridges are often preferred to enhance mobility.

[0006] It would be desirable to provide a cartridge with a compact design. It would be desirable to provide an aerosol-generating device with a compact design. It would be desirable to provide an aerosol-generating system with a compact design.

[0007] It would be desirable to provide a cartridge for an aerosol-generating device which may reduce or avoid leakage of aerosol-forming substrate. It would be desirable to provide a cartridge for an aerosol-generating device which may reduce or avoid leakage of aerosol-forming substrate during transport.

[0008] In accordance with a first aspect of the present disclosure, there is provided a cartridge for an aerosol-generating system. The cartridge may comprise a housing. The housing may define an airflow passage from an air inlet to an air outlet. The cartridge may comprise a liquid reservoir within the housing. The cartridge may comprise at least one liquid absorbing element in fluid communication with, and preferably within, the airflow passage. The cartridge may comprise a heater assembly. The heater assembly may extend in or across the airflow passage. The heater assembly may comprise a heating element. The heater assembly may be configured to wick liquid from the liquid reservoir across the heating element. The heater assembly may be positioned in the airflow passage between the at least one liquid absorbing element and the air outlet.

[0009] In one embodiment, there is provided a cartridge for an aerosol-generating system. The cartridge comprises a housing, the housing defines 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 airflow passage, and a heater assembly, the heater assembly extending in or across the airflow passage, 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 passage between the at least one liquid absorbing element and the air outlet.

[0010] The at least one liquid absorbing element is outside the liquid reservoir and positioned to absorb liquid that has escaped from the heater assembly into the airflow passage. The at least one liquid absorbing element may be positioned within the airflow passage in a manner that air can flow past the liquid absorbing element to reach the heater assembly. The at least one liquid absorbing element may be positioned within the airflow passage such that it is positioned outside of an air flow generated within the airflow passage from the air inlet to the air outlet during use. For example, the at least one liquid absorbing element may be held in a recess or blind cavity within the airflow passage. The at least one liquid absorbing element may be positioned within the airflow passage in a manner that air can flow through the at least one liquid absorbing element to reach the heater assembly.

[0011] The at least one liquid absorbing element may be positioned to be in fluid communication with the airflow passage at a position upstream of the heater assembly. As used herein, the term “upstream” refers to the direction of air flow through the airflow passage from the air inlet to the air outlet. A position in the airflow passage upstream of the heater assembly is therefore closer to the air inlet than the heater assembly is to the air inlet, in the direction of air flow from the air inlet to the air outlet.

[0012] 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 absorbing element is positioned between the heater assembly and the connection end. A pressure difference or a temperature difference between the liquid reservoir and the external environment, or gravity, may 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 in between uses once the cartridge is unsealed. Advantageously, the position of the at least one liquid absorbing element prevents liquid aerosol-forming substrate from leaving the cartridge through the connection end by absorbing the aerosol-forming substrate.

[0013] As used herein, “aerosol-forming substrate” refers to a substrate capable of releasing volatile compounds that can form an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate. An aerosol-forming substrate is typically contained in a liquid reservoir.

[0014] The connection end may connect to a device comprising a power supply, the cartridge and the device may together form the aerosol-generating system. In the system, the device and the cartridge cooperate to generate a respirable aerosol.

[0015] The cartridge may comprise a mouthpiece through which the user draws air in use. The mouthpiece may be positioned at the mouth end of the cartridge. The mouth end of the housing may comprise the mouthpiece. The mouthpiece may be formed integrally with the housing. The mouthpiece may be formed separately from the housing and connected to the housing. The mouthpiece may be connected to the housing by an interference fit. The mouthpiece may be connected to the housing by adhesive. The cartridge may comprise a longitudinal axis extending between the mouth end and the connection end of the cartridge. The mouth end may also be referred to as the proximal end of the cartridge and the connection end may also be referred to as the distal end of the cartridge.

[0016] The airflow passage may extend from the air inlet at the connection end to the air outlet at the mouth end.

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

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

[0019] The at least one liquid absorbing element may be held in a recess defined in the housing. The recess may have an open end facing the air outlet end and a closed end opposite the open end. A closed end ensures that the liquid absorbing element is securely held in the airflow passage and reduces the possibility of liquid escape. A closed end may 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 may comprise an outer housing and an inner housing, at least a portion of the airflow passage being within the inner housing, and the reservoir being defined between the outer housing and inner housing.

[0021] The at least one liquid absorbing element may comprise an internal liquid absorbing element, wherein the internal liquid absorbing element is held in a recess defined in the inner housing. Advantageously, the internal liquid absorbing element acts as a store for aerosol-forming substrate droplets that leave the heater assembly. Aerosol-forming substate that has not been vapourised is less likely to leave the airflow passage, either through the mouthpiece or through the connection end, if it is retained in the internal liquid absorbing element. The internal liquid absorbing element may comprise a sponge material. The internal liquid absorbing element may comprise a foam material.

[0022] The outer housing may at least partially, and preferably fully, circumscribe the inner housing. The air inlet may be provided in the outer housing.

[0023] The heater assembly may be supported in the inner housing. The heater assembly may extend into or across the airflow passage within the inner housing. Advantageously, this arrangement allows air to flow past the heater assembly when it is in use, so vapourised aerosol-forming substrate is entrained in the airflow and condenses to form an aerosol. This arrangement may allow a large surface area of the heater to be exposed to the airflow, allowing for a large volume of aerosol to be generated in a small cartridge.

[0024] The cartridge may have an initial configuration where the liquid reservoir is sealed from the heater assembly. The inner housing may 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 chance of aerosol forming substrate escaping from the liquid reservoir prior to use or between uses. The initial configuration may be a pre-use configuration of a cartridge. Before use, aerosolforming substrate may be securely retained in the cartridge if the cartridge is in the initial configuration. In the initial configuration, the aerosol-forming substrate may be sealed from the external environment and in particular prevented from contact with oxygen and moisture. This may allow for a longer shelflife of the cartridge.

[0025] The inner housing may comprise an engagement surface. The engagement surface of the inner housing may be accessible from an exterior of the cartridge to allow the inner housing to be moved out of the initial position. The engagement surface may be located on the distal end of the cartridge. The cartridge may be configured such that the engagement surface can be pushed by a pushing means so the inner housing moves out of the initial configuration. Advantageously, this configuration means that the liquid reservoir will remain sealed until the inner housing is moved in a specific way, meaning that aerosol-forming substrate is securely sealed when the cartridge is not in use.

[0026] The engagement surface may be circumscribed by the outer housing. The engagement surface may be accessible only through a connection end of the outer housing. Advantageously, this means that the reservoir may 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 accidently unsealed when not in use, for example when in a user’s pocket or during transport. The aperture in the connection end of the outer housing may be an air inlet. The aperture in the connection end of the outer housing may also be an engagement opening allowing access to the engagement surface. Alternatively, or in addition, the air inlet may be provided by a different opening in the outer housing.

[0027] The inner housing may be generally tubular. The inner housing may have an open end at the air outlet and a closed end opposite the open end. Advantageously, a closed end can retain aerosolforming substrate .

[0028] The at least one liquid absorbing element may be held in the closed end of the inner housing. Advantageously, this configuration prevents liquid droplets from leaving the cartridge. The at least one liquid absorbing element may be held in a recess formed by the closed end of the inner housing.

[0029] One or more air inlet openings may be provided in a wall of the inner housing between the open end and the closed end. The one or more air inlet openings may allow air into the inner housing.

[0030] The engagement surface may be formed by the closed end of the inner housing.

[0031] The inner housing may comprise a reservoir sealing flange that engages the outer housing in an initial position to seal the liquid reservoir from the heater assembly. Movement of the inner housing from the initial position relative to the outer housing may disengage the sealing flange from the outer housing, allowing liquid from the liquid reservoir to pass to the heater assembly. Advantageously, this configuration retains the aerosol-forming substrate in the reservoir when the cartridge is not in use. A sealing flange may also prevent oxidation of the aerosol-forming substrate by sealing it off from ambient air, therefore increasing the shelf-life of the cartridge. The sealing flange may circumscribe an outer portion of the inner housing. The sealing flange may be provided as a seal lip. The seal lip may comprise a hook-like profile.

[0032] The at least one liquid absorbing element may comprise an external liquid absorbing element positioned in a portion of the airflow passage between the inner housing and outer housing. Advantageously, this may provide an additional means for absorbing liquid in case the internal liquid absorbing element becomes saturated with liquid.

[0033] The inner housing may engage the outer housing at a sealing interface between the heater assembly and the connection end of the cartridge. A liquid space may 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 may 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 may be such that a seal is maintained between the inner housing and the outer housing even as the inner housing moves relative to the outer housing in a longitudinal direction.

[0034] The sealing interface may comprise a sealing element, such as an O-ring, that is fixed to or part of the inner housing or outer housing. The inner housing may comprise guiding means to hold the O-ring in position. The O-ring may exhibit a compression ratio of between 15 percent and 25 percent, preferably between 18 percent and 22 percent, more preferably of about 20 percent, when the inner housing is in the initial configuration.

[0035] The cartridge may comprise a further liquid absorbing element within the inner housing. The further liquid absorbing element may be located at the air outlet end of the airflow passage. The further liquid absorbing element may be located upstream from the heater assembly. Advantageously, the further liquid absorbing element may act as a temporary reservoir for un-vapourised liquid aerosolforming 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 pass out of the air outlet and potentially into the mouth of a user.

[0036] The cartridge may comprise a porous member between the liquid reservoir and the heater assembly. The porous member may be fluid permeable. The porous member may be arranged to allow migration of the aerosol-forming substrate from the liquid reservoir to the heater assembly. The porous member may limit a rate of flow of the liquid aerosol-forming substrate from the liquid reservoir to the heater assembly.

[0037] The porous member may be positioned between the inner housing and outer housing of the cartridge.

[0038] The porous member may comprise an open celled foam material.

[0039] The at least one heating element may 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 be kept sealed from any electrical connections during the shelf life and also in operation when coupled to an aerosol-generating device.

[0040] As used herein, “susceptor element” means an element that is heatable by penetration with a varying magnetic field. A susceptor element is typically heatable by at least one of Joule heating through induction of eddy currents in the susceptor element, and hysteresis losses.

[0041] The susceptor element may comprise a susceptor material. The susceptor material may be any material that can be inductively heated to a temperature sufficient to aerosolize an aerosol-forming substrate. The following examples and features concerning the susceptor may apply to the susceptor element of the cartridge. Suitable materials for the susceptor material include graphite, molybdenum, silicon carbide, stainless steels, niobium, aluminium, nickel, nickel containing compounds, titanium, and composites of metallic materials. Preferred susceptor materials comprise a metal or carbon. Advantageously the susceptor material may comprise or consists of a ferromagnetic or ferri-magnetic material, for example, ferritic iron, a ferromagnetic alloy, such as ferromagnetic steel or stainless steel, ferromagnetic particles, and ferrite. A suitable susceptor material may be, or comprise, aluminium. The susceptor material may comprise more than 5 percent, preferably more than 20 percent, more preferably more than 50 percent, or more than 90 percent of ferromagnetic, ferri-magnetic or paramagnetic materials. Preferred susceptor materials may be heated to a temperature in excess of 250 degrees Celsius without degradation.

[0042] The susceptor element may be formed from a single material layer. The single material layer may be a steel layer.

[0043] The susceptor element may be substantially flat. Substantially flat may be defined as the susceptor element comprising both a width and a height much greater than a depth. The susceptor element may comprise a single layer of susceptor material. The susceptor element may comprise two or more layers of susceptor material.

[0044] The heater assembly may be a flat heater assembly. The heater assembly may be a tubular assembly.

[0045] The heating element may be a mesh heating element. The mesh heating element may be configured to wick liquid. A mesh susceptor element may obviate the need for a separate wicking element. A mesh heating element or mesh susceptor element may provide for more efficient vaporisation of liquid aerosol-forming substrate. Advantageously, this may reduce manufacturing complexity and cost.

[0046] The heater assembly may comprise a wicking material. The wicking material may be provided in addition to the heating element. The wicking material may be configured to wick liquid aerosolforming substrate across the heater element. The wicking material may be provided as a layer of wicking material parallel to the heating element. The wicking material may be provided as a plurality of layers of wicking material. The heating element may be provided between the plurality of layers of wicking material. The wicking material may comprise cotton or glass fibre, or a porous ceramic.

[0047] The cartridge may comprise a nicotine containing liquid. The liquid aerosol-forming substrate may comprise nicotine. The nicotine containing liquid aerosol-forming substrate may be a nicotine salt matrix. The liquid aerosol-forming substrate may comprise plant-based material. The liquid aerosol-forming substrate may comprise tobacco. The liquid aerosol-forming substrate may comprise a tobacco-containing material containing volatile tobacco flavour compounds, which are released from the aerosol-forming substrate upon heating. The liquid aerosol-forming substrate may comprise homogenised tobacco material. The liquid aerosol-forming substrate may comprise a non-tobaccocontaining material. The liquid aerosol-forming substrate may comprise homogenised plant-based material.

[0048] The liquid aerosol-forming substrate may comprise one or more aerosol-formers. An aerosolformer is 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 temperature of operation of the system. Examples of suitable aerosol formers include glycerine 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 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. The liquid aerosol-forming substrate may comprise water, solvents, ethanol, plant extracts and natural or artificial flavours. The liquid aerosolforming substrate may comprise nicotine and at least one aerosol former. The aerosol former may be glycerine or propylene glycol. The aerosol former may comprise both glycerine and propylene glycol. The liquid aerosol-forming substrate may have a nicotine concentration of between about 0.5% and about 10%, for example about 2%.

[0049] The inner and outer housings may comprise any suitable material or combination of materials. Examples of suitable materials include metals, alloys, plastics or composite materials containing one or more of those materials, or thermoplastics that are suitable for food or pharmaceutical applications, for example polypropylene, polyetheretherketone (PEEK) and polyethylene. The material is preferably light and non-brittle.

[0050] The cartridge may comprise an identifying element at the mouth end. The identifying element may identify the type of aerosol-forming substrate with the cartridge. The identifying element may be fixed to the outer housing.

[0051] In accordance with a second aspect of the present disclosure, there is provided a cartridge for an aerosol-generating system. The cartridge may comprise an airflow passage extending through the cartridge from an air inlet to an air outlet. The cartridge may comprise a housing. The housing may comprise an outer housing and an inner housing. At least a portion of the airflow passage may be within the inner housing. The cartridge may comprise a liquid reservoir defined between the outer housing and inner housing. The cartridge may comprise a heater assembly extending into or across the airflow passage. The heater assembly may comprise a heating element. The heater assembly may be configured to wick liquid from the liquid reservoir across the heating element. The liquid reservoir may be sealed from the heater assembly. The inner housing may comprise an engagement surface. The inner housing may be configured to move relative to the outer housing to unseal the liquid reservoir and allow liquid from the reservoir to pass to the heater assembly when the engagement surface is pushed towards the liquid reservoir.

[0052] In one embodiment in accordance with this aspect, there is provided a cartridge for an aerosolgenerating system. The cartridge comprises an airflow passage 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 passage being within the inner housing, a liquid reservoir being defined between the outer housing and inner housing, a heater assembly extending into or across the airflow passage, 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 to unseal the liquid reservoir and allow liquid from the reservoir to pass to the heater assembly when the engagement surface is pushed towards the liquid reservoir. Advantageously, this configuration prevents accidental unsealing of the cartridge, only a portion of the engagement surface can be accessed and pushed. The cartridge may be less likely to be unsealed in packaging or in a user’s pocket.

[0053] The sealed configuration of the reservoir may be a pre-use configuration of a cartridge. Before use, aerosol-forming substrate may be securely retained in the cartridge if the cartridge is in the sealed configuration. In the sealed configuration, the aerosol-forming substrate may be sealed from the external environment and in particular prevented from contact with oxygen and moisture. This may allow for a longer shelf-life of the cartridge.

[0054] Preferably, the air outlet is at a mouth end of the cartridge and a connection end of the cartridge is opposite the mouth end. The connection end may connect to a device comprising a power supply, the cartridge and the device may together form the aerosol-generating system. In the system, the device and the cartridge cooperate to generate a respirable aerosol.

[0055] The cartridge may comprise a mouthpiece through which the user draws air in use. The mouthpiece may be positioned at the mouth end of the cartridge. The mouth end of the housing may comprise the mouthpiece. The mouthpiece may be formed integrally with the housing. The mouthpiece may be formed separately from the housing and connected to the housing. The mouthpiece may be connected to the housing by an interference fit. The mouthpiece may be connected to the housing by adhesive.

[0056] The cartridge may comprise a longitudinal axis extending between the mouth end and the connection end of the cartridge. The mouth end may also be referred to as the proximal end of the cartridge and the connection end may also be referred to as the distal end of the cartridge.

[0057] The airflow passage may extend from the air inlet at the connection end to the air outlet at the mouth end.

[0058] The cartridge may comprise at least one liquid absorbing element within the airflow passage. The at least one liquid absorbing element may comprise one or more celled porous members. Advantageously, one or more porous members are capable of retaining liquid. This is beneficial so the at least one liquid absorbing element acts absorbs and retains aerosol-forming substrate that has migrated into the airflow passage.

[0059] The at least one liquid absorbing element may comprise a sponge material. The at least one liquid absorbing element may comprise a foam material.

[0060] The at least one liquid absorbing element may be held in a recess defined in the housing. The recess may have an open end facing the air outlet end and a closed end opposite the open end. A closed end ensures that the liquid absorbing element is securely held in the airflow passage and reduces the possibility of liquid escape. A closed end may also provide the engagement surface.

[0061] The at least one liquid absorbing element may comprise an internal liquid absorbing element, wherein the internal liquid absorbing element is held in a recess defined in the inner housing. Advantageously, the internal liquid absorbing element acts as a store for aerosol-forming substrate droplets that leave the heater assembly. Aerosol-forming substate that has not been vapourised is less likely to leave the airflow passage, either through the mouthpiece or through the connection end, if it is retained in the internal liquid absorbing element. The internal liquid absorbing element may comprise a sponge material. The internal liquid absorbing element may comprise a foam material.

[0062] The outer housing may at least partially, and preferably fully, circumscribe the inner housing.

[0063] The heater assembly may be supported in the inner housing. The heater assembly may extend into or across the airflow passage within the inner housing. Advantageously, this arrangement allows air to flow past the heater assembly when it is in use, so vapourised aerosol-forming substrate is entrained in the airflow and condenses to form an aerosol. This arrangement may allow a large surface area of the heater to be exposed to the airflow, allowing for a large volume of aerosol to be generated in a small cartridge.

[0064] The engagement surface may be located on the distal end of the cartridge. The engagement surface may be circumscribed by the outer housing. The engagement surface may be accessible only though a connection end of the outer housing. Advantageously, this means that the reservoir may be move 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 accidently unsealed when not in use, for example when in a user’s pocket or during transport.

[0065] The inner housing may be generally tubular. The inner housing may have an open end at the air outlet and a closed end opposite the open end. Advantageously, a closed end can retain aerosolforming substrate.

[0066] The at least one liquid absorbing element may be held in the closed end of the inner housing. Advantageously, this configuration prevents liquid droplets from leaving the cartridge. The at least one liquid absorbing element may be held in a recess formed by the closed end of the inner housing.

[0067] One or more air inlet openings may be provided in a wall of the inner housing between the open end and the closed end. The one or more air inlet openings may allow air into the inner housing.

[0068] The engagement surface may be formed by the closed end of the inner housing. The inner housing may comprise a reservoir sealing flange that engages the outer housing in an initial position to seal the liquid reservoir from the heater assembly. Movement of the inner housing from the initial position relative to the outer housing may disengage the sealing flange from the outer housing, allowing liquid from the liquid reservoir to pass to the heater assembly. Advantageously, this configuration retains the aerosol-forming substrate in the reservoir when the cartridge is not in use. A sealing flange may also prevent oxidation of the aerosol-forming substrate by sealing it off from ambient air, therefore increasing the shelf-life of the cartridge.

[0069] The sealing flange may circumscribe an outer portion of the inner housing. The sealing flange may be provided as a seal lip. The seal lip may comprise a hook-like profile.

[0070] The at least one liquid absorbing element may comprise an external liquid absorbing element positioned in a portion of the airflow passage between the inner housing and outer housing. Advantageously, this may provide an additional means for absorbing liquid in case the internal liquid absorbing element becomes saturated with liquid. The reservoir may 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 external liquid absorbing element may be defined between the second portion of the outer housing and the second portion of the inner housing.

[0071] The inner housing may engage the outer housing at a sealing interface between the heater assembly and the connection end of the cartridge. A liquid space may 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 may 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 may be such that a seal is maintained between the inner housing and the outer housing even as the inner housing moves relative to the outer housing in a longitudinal direction.

[0072] The sealing interface may comprise a sealing element, such as an O-ring, that is fixed to or part of the inner housing or outer housing. The inner housing may comprise guiding means to hold the O-ring in position. The O-ring may exhibit a compression ratio of between 15 percent and 25 percent, preferably between 18 percent and 22 percent, more preferably of about 20 percent, when the inner housing is in the initial configuration.

[0073] The cartridge may comprise a further liquid absorbing element within the inner housing. The further liquid absorbing element may be located at the air outlet end of the airflow passage. The further liquid absorbing element may be located upstream from the heater assembly. Advantageously, the further liquid absorbing element may act as a temporary reservoir for un-vapourised liquid aerosolforming 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 pass out of the air outlet and potentially into the mouth of a user.

[0074] The cartridge may comprise a porous member between the liquid reservoir and the heater assembly. The porous member may be fluid permeable. The porous member may be arranged to allow migration of the aerosol-forming substrate from the liquid reservoir to the heater assembly. The porous member may limit a rate of flow of the liquid aerosol-forming substrate from the liquid reservoir to the heater assembly. For example, increased temperature and pressure differences between the liquid reservoir and the external environment caused by activation of the heater assembly may cause an undesirable increase in liquid flow rate from the liquid reservoir. The porous member may control the flow rate by acting as a buffer, reducing flow rate of the aerosol-forming substrate to the heater assembly.

[0075] The porous member may be positioned between the inner housing and outer housing of the cartridge.

[0076] The porous member may comprise an open celled foam material.

[0077] The at least one heating element may 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 be kept sealed from any electrical connections during the shelf life and also in operation when coupled to an aerosol-generating device.

[0078] The susceptor element may comprise a susceptor material. The susceptor material may be any material that can be inductively heated to a temperature sufficient to aerosolize an aerosol-forming substrate. The following examples and features concerning the susceptor may apply to the susceptor element of the cartridge. Suitable materials for the susceptor material include graphite, molybdenum, silicon carbide, stainless steels, niobium, aluminium, nickel, nickel containing compounds, titanium, and composites of metallic materials. Preferred susceptor materials comprise a metal or carbon. Advantageously the susceptor material may comprise or consists of a ferromagnetic or ferri-magnetic material, for example, ferritic iron, a ferromagnetic alloy, such as ferromagnetic steel or stainless steel, ferromagnetic particles, and ferrite. A suitable susceptor material may be, or comprise, aluminium. The susceptor material may comprise more than 5 percent, preferably more than 20 percent, more preferably more than 50 percent, or more than 90 percent of ferromagnetic, ferri-magnetic or paramagnetic materials. Preferred susceptor materials may be heated to a temperature in excess of 250 degrees Celsius without degradation.

[0079] The susceptor element may be formed from a single material layer. The single material layer may be a steel layer.

[0080] The susceptor element may be substantially flat. Substantially flat may be defined as the susceptor element comprising both a width and a height much greater than a depth. The susceptor element may comprise a single layer of susceptor material. The susceptor element may comprise two or more layers of susceptor material.

[0081] The heater assembly may be a flat heater assembly. The heater assembly may be a tubular assembly.

[0082] The heating element may be a mesh heating element. The mesh heating element may be configured to wick liquid. A mesh susceptor element may obviate the need for a separate wicking element. A mesh heating element or mesh susceptor element may provide for more efficient vaporisation of liquid aerosol-forming substrate. Advantageously, this may reduce manufacturing complexity and cost.

[0083] The heater assembly may comprise a wicking material. The wicking material may be provided in addition to the heating element. The wicking material may be configured to wick liquid aerosolforming substrate across the heater element. The wicking material may be provided as a layer of wicking material parallel to the heating element. The wicking material may be provided as a plurality of layers of wicking material. The heating element may be provided between the plurality of layers of wicking material. The wicking material may comprise cotton or glass fibre, or a porous ceramic.

[0084] The cartridge may comprise a nicotine containing liquid. The liquid aerosol-forming substrate may comprise nicotine. The nicotine containing liquid aerosol-forming substrate may be a nicotine salt matrix. The liquid aerosol-forming substrate may comprise plant-based material. The liquid aerosol-forming substrate may comprise tobacco. The liquid aerosol-forming substrate may comprise a tobacco-containing material containing volatile tobacco flavour compounds, which are released from the aerosol-forming substrate upon heating. The liquid aerosol-forming substrate may comprise homogenised tobacco material. The liquid aerosol-forming substrate may comprise a non-tobaccocontaining material. The liquid aerosol-forming substrate may comprise homogenised plant-based material.

[0085] The liquid aerosol-forming substrate may comprise one or more aerosol-formers. An aerosolformer is 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 temperature of operation of the system. Examples of suitable aerosol formers include glycerine 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 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. The liquid aerosol-forming substrate may comprise water, solvents, ethanol, plant extracts and natural or artificial flavours. The liquid aerosolforming substrate may comprise nicotine and at least one aerosol former. The aerosol former may be glycerine or propylene glycol. The aerosol former may comprise both glycerine and propylene glycol. The liquid aerosol-forming substrate may have a nicotine concentration of between about 0.5% and about 10%, for example about 2%.

[0086] The inner and outer housings may comprise any suitable material or combination of materials. Examples of suitable materials include metals, alloys, plastics or composite materials containing one or more of those materials, or thermoplastics that are suitable for food or pharmaceutical applications, for example polypropylene, polyetheretherketone (PEEK) and polyethylene. The material is preferably light and non-brittle.

[0087] The cartridge may comprise an identifying element at the mouth end. The identifying element may identify the type of aerosol-forming substrate with the cartridge. The identifying element may be fixed to the outer housing. In accordance with a third aspect of the present disclosure, there is provided an aerosolgenerating system comprising a cartridge according to the first or second embodiment of the present disclosure and a device, the device comprising a power supply.

[0088] The system may be configured so that the inner housing is moved from the initial position as a consequence of the cartridge being coupled to the device. Advantageously, this configuration may keep the cartridge in a sealed state, where liquid aerosol-forming substrate does not leak from the reservoir, when the aerosol-generating system is not in use.

[0089] The device may comprise a contact surface that engages the 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 that aerosol-forming substrate leaves the liquid reservoir when the device is in use. This configuration may prevent the cartridge from leaking in a user’s pocket or in packaging as the engagement surface is moved by the contact surface of the device.

[0090] The aerosol generating system may 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. An engagement mechanism is advantageous, so the cartridge and device stay in contact with one another when the aerosol generating system is in use. This configuration may allow consistent power supply to the cartridge.

[0091] The device may comprise one or more inductor coils configured to generate a variable magnetic flux through the heating element. Advantageously, heating a heating element in this way may be more efficient than other forms of heating, for example, electrical resistance heating.

[0092] At least one of the inductor coils may be a planar inductor coil and the heating element may be planar and arranged parallel to the inductor coil.

[0093] The device may comprise a cavity configured to receive at least a connection end of the cartridge. The cavity may be tubular in shape. The cavity may have a simple shape that easily receives at least a connection end of the cartridge.

[0094] The aerosol-generating system may be a handheld aerosol-generating system. The aerosolgenerating system may be a handheld aerosol-generating system configured to allow a user to suck on a mouthpiece to draw an aerosol through a first air outlet. The aerosol-generating system may have a size comparable to a conventional cigar or cigarette. The aerosol-generating system may have a total length between about 25 mm and about 150 mm. The aerosol-generating system may have an external diameter between about 5 mm and about 30mm.

[0095] The power supply may be a DC power supply. The power supply may be a battery. The battery may be a Lithium based battery, for example a Lithium-Cobalt, a Lithium-lron-Phosphate, a Lithium Titanate or a Lithium-Polymer battery. The battery may be a Nickel metal hydride battery or a Nickel cadmium battery. The power supply may be another form of charge storage device such as a capacitor.

[0096] The heater assembly may comprise one or more inductor elements. The inductor element may generate a varying magnetic field when a varying current is supplied to the inductor element. The one or more inductor element may be configured to generate a variable magnetic flux through the susceptor element. The device may comprise the one or more inductor element. The one or more inductor element may be configured to generate a varying magnetic field in the device cavity. The one or more inductor element may be arranged outside of the device cavity. The one or more inductor element may be arranged to at least partially surround the cavity. When the cartridge is coupled to the aerosol-generating device, the one or more inductor element may at least partially surround the susceptor element. The one or more inductor element may be an inductor coil. The inductor coil may be a helical coil.

[0097] As used herein, “varying current” refers to a current that varies with time. An inductor element may generate a varying magnetic field when a varying electric current is supplied to the inductor element. The term “varying current” is intended to include alternating currents. Where the varying current is an alternating current, the alternating current generates an alternating magnetic field. The varying current may be an alternating current.

[0098] As used herein, “alternating current” refers to a current that periodically reverses direction. The alternating current may have any suitable frequency. Suitable frequencies for the alternating current may be between 100 kilohertz (kHz) and 30 megahertz (MHz)

[0099] The inductor element may be formed from any suitable material. The inductor element may be formed from at least one of: silver, gold, aluminium, brass, zinc, iron, nickel, and alloys of thereof, and electrically conductive ceramics, such as yttrium-doped zirconia, indium tin oxide, and yttrium doped titanate.

[0100] The aerosol-generating system may be a handheld aerosol-generating system configured to allow a user to puff on a mouthpiece to draw an aerosol through a mouth end opening. The aerosolgenerating system may have a size comparable to a conventional cigar or cigarette. The aerosolgenerating system may have a total length between about 30 millimetres and about 150 millimetres. The aerosol-generating system may have an external diameter between about 5 millimetres and about 30 millimetres.

[0101] The aerosol-generating system may be configured to deliver nicotine or cannabinoids to a user. The aerosol-generating system may be an electrically operated smoking device.

[0102] The control circuitry may comprise a microprocessor. The microprocessor may be a programmable microprocessor, a microcontroller, or an application specific integrated chip (ASIC) or other electronic circuitry capable of providing control. The control circuitry may be configured to supply power to the at least one inductor coil continuously following activation of the device or may be configured to supply power intermittently, such as on a puff-by-puff basis. The power may be supplied to the inductive heating assembly in the form of pulses of electrical current, for example, by means of pulse width modulation (PWM). The control circuitry may comprise DC / AC inverter, which may comprise a Class-D or Class-E power amplifier. The control circuitry may comprise further electronic components. For example, in some embodiments, the control circuitry may comprise any of: sensors, switches, display elements. It will be appreciated that any features described herein in relation to one embodiment of a cartridge or an aerosol-generating system may also be applicable to other embodiments of cartridges and aerosol-generating systems according to this disclosure. A feature described in relation to one embodiment may be equally applicable to another embodiment in accordance with this disclosure. It will also be appreciated that an aerosol-generating system according to this disclosure may be provided in an aerosol-generating device without a cartridge. Accordingly, any of the features described herein with relation to a cartridge may be equally applicable to an aerosol-generating device.

[0103] The invention is defined in the claims. However, below there is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

[0104] Ex1 . A cartridge for an aerosol-generating system, the cartridge comprising: a housing, the 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 airflow passage; and a heater assembly, the heater assembly extending into or across the airflow passage, 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 passage between the at least one liquid absorbing element and the air outlet.

[0105] Ex2. A 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 absorbing element is positioned between the heater assembly and the connection end.

[0106] 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.

[0107] Ex4. A cartridge according to example Ex1 or Ex2, wherein the cartridge comprises a longitudinal axis extending between the mouth end (also referred to as a proximal end) and the connection end (also referred to as a distal end) of the cartridge.

[0108] Ex5. A cartridge according to example Ex2, Ex3 or Ex4, wherein the airflow passage extends from the air inlet at the connection end to the air outlet at the mouth end.

[0109] 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.

[0110] Ex7. A cartridge according to any one of the preceding examples, wherein the at least one liquid absorbing element comprises one or more open celled porous members.

[0111] Ex8. A cartridge according to any one of the preceding examples, 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. 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 passage being within the inner housing, and the reservoir being defined between the outer housing and inner housing.

[0112] Ex10. A cartridge according to example Ex9 wherein the at least one liquid absorbing element comprises an internal liquid absorbing element, wherein the internal liquid absorbing element is held in a recess defined in the inner housing.

[0113] Ex11. A cartridge according to example Ex9 or Ex10, wherein the outer housing at least partially, and preferably fully, circumscribes the inner housing.

[0114] Ex12. A cartridge according to example Ex9, Ex10 or Ex11 , wherein the heater assembly is supported in the inner housing.

[0115] Ex13. A cartridge according to any one of examples Ex9 to Ex12, wherein the heater assembly extends into or across the airflow passage within the inner housing.

[0116] Ex14. A cartridge according to any one of examples Ex9 to Ex13, wherein in an initial configuration the liquid reservoir is sealed 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.

[0117] Ex15. A cartridge according to example Ex14, wherein the inner housing has an engagement surface, wherein the engagement surface of the inner housing is accessible from an exterior of cartridge to allow inner housing to be moved out of the initial position.

[0118] Ex16. A cartridge according to example Ex15 wherein the engagement surface is circumscribed by the outer housing, preferably such that the engagement surface is accessible only through a connection end of the outer housing.

[0119] Ex17. A 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.

[0120] Ex18. A cartridge according to example Ex17, wherein the liquid absorbing element is held in the closed end of the inner housing.

[0121] Ex19. A 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.

[0122] Ex20. A 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.

[0123] Ex21 . A cartridge according to example Ex20, wherein the liquid absorbing element is held in a recess formed by the closed end of the inner housing.

[0124] Ex22. A cartridge according to any one of examples Ex9 to Ex21 , wherein the inner housing comprises a reservoir sealing flange that engages the outer housing in an initial position to seal the liquid reservoir from the heater assembly, and wherein movement of the inner housing from the initial position relative to the outer housing disengages the sealing flange from the outer housing allowing liquid from the liquid reservoir to pass to the heater assembly.

[0125] Ex23. A cartridge according to any one of examples Ex9 to Ex22, wherein the outer housing comprises the air inlet. Ex24. A cartridge according to any one of examples Ex9 to Ex23, wherein the at least one liquid absorbing element comprises an external liquid absorbing element positioned in a portion of the airflow passage between the inner housing and outer housing.

[0126] 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 so that 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.

[0127] Ex26. A cartridge according to example Ex25, wherein the sealing interface comprises a sealing element, such as an o-ring, that is fixed to or part of the inner housing.

[0128] Ex27. A cartridge according to any one of the preceding examples, comprising a further liquid absorbing element within the inner housing.

[0129] Ex28. A cartridge according to example Ex27 wherein the further liquid absorbing element is located at the air outlet end of the airflow passage.

[0130] Ex29. A cartridge according to any one of the preceding examples, further comprising a porous member between the liquid reservoir and the heater assembly.

[0131] Ex30. A cartridge according to example Ex29 wherein the porous member is positioned between the inner housing and the outer housing of the cartridge.

[0132] Ex31. A cartridge according to example Ex29 or Ex30, wherein the porous member comprises open celled foam material.

[0133] Ex32. A cartridge according to any one of the preceding examples, wherein the heating element is a susceptor element.

[0134] 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.

[0135] Ex34. A cartridge according to any preceding example, wherein the heating element is a mesh heating element configured to wick liquid.

[0136] Ex35. A cartridge according to any preceding example, comprising a nicotine containing liquid.

[0137] Ex36. A cartridge for an aerosol-generating system, the cartridge comprising: an airflow passage 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 passage being within the inner housing, a liquid reservoir being defined between the outer housing and inner housing, a heater assembly, the heater assembly extending into or across the airflow passage, 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 to unseal the liquid reservoir and allow liquid from the reservoir to pass to the heater assembly when the engagement surface is pushed towards the liquid reservoir; and wherein the outer housing surrounds the engagement surface of the inner housing and defines an engagement opening through which the engagement surface can be accessed to push the engagement surface towards the liquid reservoir.

[0138] Ex37. A cartridge according to example Ex36, wherein the air outlet is at a mouth end of the cartridge and a connection end of the cartridge is opposite the mouth end,

[0139] Ex38. A cartridge according to example Ex37 wherein the mouth end of the housing comprises a mouthpiece through which a user draws air in use.

[0140] Ex39. A cartridge according to example Ex37 or Ex38, wherein the cartridge comprises a longitudinal axis extending between the mouth end (also referred to as a proximal end) and the connection end (also referred to as a distal end) of the cartridge.

[0141] Ex40. A cartridge according to any one of examples Ex37 to Ex39, wherein the connection end is configured to connect to a device comprising a power supply.

[0142] Ex41 . A cartridge according to any one of examples Ex37 to Ex40, comprising at least one liquid absorbing element in fluid communication with, and preferably within, the airflow passage and wherein the at least one liquid absorbing element is positioned between the heater assembly and the connection end.

[0143] Ex42. A cartridge according to example Ex41 , wherein the at least one liquid absorbing element comprises one or more open celled porous members.

[0144] Ex43. A 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.

[0145] Ex44. A cartridge according to example Ex41 , Ex42 or Ex43 wherein the at least one liquid absorbing element comprises an internal liquid absorbing element, wherein the internal liquid absorbing element is held in a recess defined in the inner housing.

[0146] Ex45. A cartridge according to any one of examples Ex36 to Ex44, wherein the outer housing at least partially, and preferably fully, circumscribes the inner housing.

[0147] Ex46. A cartridge according to any one of examples Ex36 to Ex45, wherein the heater assembly is supported in the inner housing.

[0148] Ex47. A cartridge according to any one of examples Ex36 to Ex46, wherein the heater assembly extends into or across the airflow passage within the inner housing.

[0149] Ex48. A 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.

[0150] Ex49. A cartridge according to example Ex48, wherein the liquid absorbing element of example Ex41 is held in the closed end of the inner housing.

[0151] Ex50. A 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. Ex51. A cartridge according to example Ex48, Ex49 or Ex50, wherein the engagement surface is formed by the closed end of the inner housing.

[0152] Ex52. A 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.

[0153] Ex53. A cartridge according to any one of examples Ex36 to Ex52, wherein the inner housing comprises a reservoir sealing flange that engages the outer housing in an initial position to seal the liquid reservoir from the heater assembly, and wherein movement of the inner housing from the initial position relative to the outer housing disengages the sealing flange from the outer housing allowing liquid from the liquid reservoir to pass to the heater assembly.

[0154] Ex54. A cartridge according to any one of examples Ex35 to Ex53, wherein the outer housing comprises the air inlet.

[0155] Ex55. A cartridge according to any one of examples Ex41 to Ex54, wherein the at least one liquid absorbing element comprises an external liquid absorbing element positioned in a portion of the airflow passage between the inner housing and outer housing.

[0156] Ex56. A cartridge according to any one of examples Ex36 to Ex55, wherein the inner housing engages the outer housing at a sealing interface between the heater assembly and the connection end of the cartridge so that 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.

[0157] Ex57. A cartridge according to example Ex56, wherein the sealing interface comprises a sealing element, such as an o-ring, that is fixed to or part of the inner housing.

[0158] Ex58. A cartridge according to any one of examples 36 to 57, comprising a further liquid absorbing element within the inner housing.

[0159] Ex59. A cartridge according to example Ex58 wherein the further liquid absorbing element is located at the air outlet end of the airflow passage.

[0160] Ex60. A cartridge according to any one of examples Ex36 to Ex59, further comprising a porous member between the liquid reservoir and the heater assembly.

[0161] Ex61 . A cartridge according to example Ex60 wherein the porous member is positioned between the inner housing and the outer housing of the cartridge.

[0162] Ex62. A cartridge according to example Ex60 or Ex61 , wherein the porous member comprises open celled foam material.

[0163] Ex63. A cartridge according to any one of examples Ex36 to Ex62, wherein the heating element is a susceptor element.

[0164] 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.

[0165] Ex65. A cartridge according to examples Ex36 to Ex64, wherein the heating elements is a mesh heating element configured to wick liquid. Ex66. A cartridge according to examples Ex36 to Ex65, comprising a nicotine containing liquid.

[0166] Ex67. An aerosol generating system comprising a cartridge according to any one of the preceding examples and a device, in use the cartridge being fixed to the device, the device comprising a power supply.

[0167] Ex68. An aerosol generating system according to example Ex67, wherein the system is configured so that the inner housing is moved from the initial position as a consequence of the cartridge being coupled to the device.

[0168] Ex69. An aerosol generating system according to example Ex68, wherein the device comprises a contact surface that engages the engagement surface on the inner housing when the cartridge is coupled to the device to urge the engagement surface towards the liquid reservoir.

[0169] Ex70. An aerosol generating system according to example 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.

[0170] 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.

[0171] Ex72. An aerosol generating system according to example Ex71 , wherein at least one of the inductor coils is a planar inductor coil and the heating element is planar and arranged parallel to the planar induction coil.

[0172] 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.

[0173] Ex74. An aerosol generating system according to example Ex73, wherein the reusable device comprises one or more inductor coils positioned around the cavity.

[0174] Ex75. An aerosol generating system according to example Ex74, wherein the one or more inductor coils comprises a helical coil surrounding at least a portion of the cavity.

[0175] 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, the end face of the protrusion forming a contact surface for engaging the engagement surface of the inner housing of the cartridge.

[0176] The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

[0177] Figure 1 A is a cross-sectional schematic view of an aerosol-generating system in accordance with the present disclosure in a sealed configuration;

[0178] Figure 1 B shows a cross-sectional schematic view of the aerosol-generating system of Fig. 1 A in a use configuration;

[0179] Figure 2 is an illustration of an embodiment of the cartridge shown in Figures 1A and 1 B; and Figure 3 is an exploded view of the cartridge of Figure 2. Figure 1 A shows a schematic illustration of an aerosol-generating system in accordance with the present disclosure, with the cartridge in a sealed configuration separated from the device. Figure 1 B shows a schematic illustration of the aerosol-generating system in a use configuration, in which the cartridge is coupled to the device and in an unsealed configuration. The system 10 comprises a cartridge 50 and a device 80, which are configured to be removably couplable together to form the aerosol-generating system 10. The cartridge of the system is shown in further detail in Figures 2 and 3. The aerosol-generating system is portable and has a size comparable to a conventional cigar or cigarette.

[0180] The cartridge 50 comprises a heater assembly 12 mounted in an inner housing 20. The heater assembly 12 in this embodiment is a susceptor assembly 12. The susceptor assembly 12 is planar, and in the form of a sheet, having a thickness dimension that is substantially smaller than a length dimension and a width dimension. The susceptor assembly 12 has a rectangular shape. In other embodiments the susceptor assembly may have a cylindrical shape or another suitable shape. The susceptor assembly 12 is configured to be heatable by penetration with an alternating magnetic field, for vaporising an aerosol-forming substrate.

[0181] The susceptor assembly 12 comprises a susceptor element. The susceptor element comprises a mesh having filaments extending in a first direction, and filaments extending in a second direction, substantially perpendicular to the first direction. The susceptor element comprises filaments of AISI 410 stainless steel, a ferritic stainless steel, extending in both the first and second directions. In other embodiments the susceptor assembly may comprise a susceptor element that comprises combinations of magnetic materials. For example, in some embodiments the susceptor element comprises filaments of AISI 410 stainless steel, a ferritic stainless steel, extending in the first direction, and filaments of AISI 316 stainless steel, an austenitic stainless steel, extending in the second directions. The susceptor assembly 12 further comprises a layer of wicking material extending parallel to the susceptor element. The wicking material is configured to wick the liquid aerosol-forming substrate across the susceptor element. The wicking element comprises a cotton. In other embodiments, the wicking material may comprise a glass fibre or a porous ceramic. The susceptor assembly may comprise two susceptor elements that sandwich a layer of wicking material.

[0182] The cartridge 50 comprises an outer housing 22 formed from a mouldable plastics material, such as polypropylene. The cartridge further comprises an inner housing 20 which generally forms a hollow cylinder, defining an internal space across which the susceptor assembly extends. The inner housing 20 comprises an open end located towards the mouth end of the cartridge 50 and a closed end opposite to the mouth end.

[0183] 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 connection of the cartridge 50 to a device 80. The susceptor assembly 12 is located towards the connection end of the cartridge 50. The external width of the outer housing 22 is greater 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 a cavity 64 of the device 80, with the shoulder 37 locating the cartridge 50 in the correct position relative to the device 80. This also enables the mouth end of the cartridge 50 to remain outside of the device 80, with the mouth end conforming to the external shape of the device 80.

[0184] The outer housing 22 is slidable relative to the inner housing between an initial, sealed configuration, as shown in Figure 1 A, and an unsealed, use configuration, as shown in Figure 1 B.The inner housing of the cartridge is configured to move when an engagement surface 42 is acted upon by a pushing means . The engagement surface 42 is part of an exterior surface of the inner housing 20 at the connection end and it is configured to interact with the device 80.

[0185] The outer housing 22 comprises a bottom housing part 38 located at the connection end of the cartridge 50. The bottom housing part 38 surrounds the bottom of the inner housing, covering the engagement surface, but comprises an opening through which the engagement surface 42 can be accessed and pushed by a pushing means.

[0186] The cartridge defines a liquid reservoir 40 holding a liquid aerosol-forming substrate 46. The liquid reservoir 40 is located towards the mouth end of the outer housing 22, and comprises an annular space defined within the outer housing 22. The reservoir surrounds an internal passage 30 that extends between the mouth end opening 34, and the open end of the inner housing 20.

[0187] The inner housing 20 further comprises a reservoir sealing flange 28 that engages with the outer housing 22 in the sealed configuration, shown in Figure 1A, to seal the liquid reservoir 40 and prevent liquid from reaching the susceptor assembly 12. In the sealed configuration, liquid aerosolforming substrate 46 contained within the liquid reservoir 40 is fluidly isolated by the reservoir sealing flange 28. Movement of the inner housing 20 relative to the outer housing 22 disengages the reservoir sealing flange 28 from the outer housing 22, allowing liquid aerosol-forming substrate 46 to pass to the susceptor assembly 12. A gap 44, allowing liquid to leave the liquid reservoir 40, is created when the inner housing 20 moves towards the unsealed configuration.

[0188] The cartridge 50 comprises 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 towards the susceptor assembly 12 when the aerosol-generating system 10 is in the use configuration. 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. The porous member 16 controls the rate at which liquid can flow to the susceptor assembly 12.

[0189] A sealing interface between the inner housing 20 and outer housing 22 is located at the connection end of the cartridge 50. The sealing interface comprises a sealing element 24. The sealing element shown in Figures 1 A and 1 B is an O-ring, that is fixed to part of the inner housing 20. The Ciring engages an inner surface of the outer housing. A liquid space is defined on the proximal side of the sealing element 24 between the inner housing 20 and outer housing 22 and a portion of the airflow passage is defined on the distal side of the sealing element 24 between the inner housing 20 and the outer housing 22. The cartridge 50 comprises an internal liquid absorbing element 36 that is held in a recess defined in the inner housing 20. The internal liquid absorbing element 36 retains liquid aerosol-forming substrate that has escaped from the susceptor assembly 12 and has not been vaporised or has condensed. The internal liquid absorbing element 36 comprises a sponge material.

[0190] The cartridge 50 further comprises an external liquid absorbing element 26 positioned in a portion of the airflow path between the inner housing 20 and the outer housing 22. The external liquid absorbing element 26 provides an additional means for absorbing liquid aerosol-forming substrate, for example, when the internal liquid absorbing element 36 becomes saturated with liquid. The external liquid absorbing element 26 comprises a sponge material.

[0191] 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 the 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.

[0192] Alternatively, the air inlet may be formed at the interface between the device and the cartridge. In that 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.

[0193] The device 80 further comprises an inductive heating arrangement arranged within the housing 62. The inductive heating arrangement includes 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, that is rechargeable 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 to 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.

[0194] When the cartridge 50 is received in the cavity 64, the susceptor assembly 12 is arranged between the inductor coils 54. Flux concentrators 56 are provided around each of the inductor coils 54 in order to contain and concentrate the magnetic field with the cavity 64. The flux concentrators may be formed from a magnetic material, such as iron.

[0195] The inductor coils 54 are configured such that when the alternating current is supplied to the inductor coils 54, the inductor coil generates an alternating magnetic field in the cavity 64. The alternating magnetic field generated by each of the inductor coils 54 is directed substantially perpendicular to the plane of the susceptor assembly 12.

[0196] When the connection end of the cartridge 50 is inserted into the cavity 64, the engagement surface 42 of the cartridge 50 comes into contact with a contact surface 68 located at the base of the cavity 64. The contact surface 68 is rigid and is configured not to move when contacted by the engagement surface 42. The contact surface 68 provides a pushing means to slide the inner housing 20 towards the mouth end, such that the reservoir sealing flange 28 unseals the liquid reservoir 40, allowing liquid aerosol-forming substate 46 to migrate towards the susceptor assembly 12. The length of the gap 44 in the use configuration is equal to the height of the contact surface 68 above the base of the cavity 64.

[0197] In operation, when a user puffs on the mouth end opening 34 of the cartridge 50, ambient air is drawn into the base of the cavity 64 through the air inlet 65, and into the cartridge 50 as shown by arrows with solid lines in Figure 1 B. The inner housing 20 comprises an airflow management component 47 that comprises air inlet openings 48 for air to enter. The air inlet openings are different to the air inlet to the cartridge, which is provided in the outer housing. The airflow management component 47 will be described in further detail below in Figures 5a, 5b and 5c. Arrows with dashed lines in Figure 1 B show the airflow within the inner housing 20. The inner housing 20 is configured to allow air to flow past the susceptor assembly 12 when the aerosol-generating system 10 is in use. Vapourised aerosol-forming substrate is then entrained in the airflow and condenses to form an aerosol.

[0198] The control circuitry 70 controls the supply of electrical power from the power supply 72 to the inductor coils 54 when the system is activated. The control circuitry may include an airflow sensor (not shown), and the control circuitry may supply electrical power to the inductor coils 54 when user puffs on the cartridge 50 are detected by the airflow sensor. This type of control is well established in aerosol-generating systems such as inhalers and e-cigarettes.

[0199] When the system 10 is activated, an alternating current is established in the inductor coils 54, which generates an alternating magnetic field in the cavity 64 that penetrates the susceptor assembly 12, causing the susceptor element to heat. Liquid aerosol-forming substrate 46 in the liquid reservoir 40 is drawn into the susceptor assembly 12 through the porous member 16. The aerosol-forming substrate is heated, and volatile compounds from the heated aerosol-forming substrate are released into the air passage of the inner housing 20, which cool to form an aerosol. The aerosol is entrained in the air being drawn through the air passage, and is drawn out of the cartridge 50 at the mouth end opening 34 for inhalation by the user.

[0200] Figure 2 shows a cartridge 50 in accordance with the embodiment of Figures 1 A and 1 B. The outer housing is shown in cross-section but the inner housing 20 is not. A flavour indicator 88 and a mouthpiece cotton disc 89 are also shown in cross section, connected to the mouth end of the outer housing, as will be described. The cartridge 50 of Figure 2 is in the use configuration. Figure 3 is an exploded view of the cartridge of Figure 2.

[0201] The inner housing 20 comprises two parts; a sealing component 49 that is connected to an airflow management component 47. The sealing component 49 comprises the 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 bottom portion 38 surrounds the airflow management component 47. An O-ring 26 on the airflow management component contacts and seals against the inner surface of the bottom portion 38. As the inner housing moves relative to the outer housing, the O-ring maintains a liquid tight seal between the inner and outer housings. A mouth end portion 93 of the outer housing engages the bottom portion. The mouth end portion includes an inner airflow tube that engages the sealing component of the inner housing to maintain a liquid tight seal around the airflow path.

[0202] In the use configuration, shown in Figure 2, the inner housing 20 has moved towards the mouth end relative to the outer housing 22, so that the reservoir sealing flange 28 has disengaged from the outer housing 22, leaving a gap for the liquid aerosol-forming substrate in the liquid reservoir 40 to travel through. Liquid aerosol-forming substrate then migrates through the porous member 16 towards the susceptor assembly 12.

[0203] The airflow management component 47 comprises an air inlet opening 48 allowing air to enter the hollow tubular interior of inner housing 20. The airflow management component may have more than one air inlet opening. The airflow management component comprises a first protrusion 61 and a second protrusion 63 which are 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 directly entering the airflow path.

[0204] The internal liquid absorbing element 36 (not shown in Figure 2 but clearly seen in Figure 3) retains liquid aerosol-forming substrate droplets that leave the susceptor assembly 12 that have not been vaporised or that might have condensed within the airflow path. The internal liquid absorbing element 36 is located inside the airflow management components below the air inlet openings 48 so as not to obstruct airflow. External liquid absorbing elements 26 are located outside of the inner housing, between the airflow management component 47 and the outer housing 22. The external liquid absorbing elements 26 are positioned in a portion of the airflow path, with spaces provided between the external liquid absorbing elements 26 for the airflow. If the internal liquid absorbing element becomes saturated, the external liquid absorbing elements 26 are capable of retaining surplus substrate droplets that pass on from the internal liquid absorbing element. The external liquid absorbing elements may also absorb any liquid that passes the O-ring.

[0205] 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 push the engagement surface 42 towards the liquid reservoir 40. The engagement opening is also an air inlet for the cartridge.

[0206] The susceptor assembly 12 and the internal liquid absorbing 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 so that the susceptor element is within the airflow passage. The wicking material extends through the slot into contact with the porous elements 16.

[0207] The internal liquid absorbing element 36 is placed in the recess formed by the closed end of the airflow management component. The internal liquid absorbing element 36 is positioned to capture liquid droplets in the inner housing that have leaked from the susceptor assembly and condensed within the inner housing. The position of the internal liquid absorbing 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. 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, past the external liquid absorbing elements to the air inlet openings 48. The airflow then passes through the inner housing, past the susceptor element to the mouth end.

[0208] The mouthpiece cotton disc 89 is a further liquid absorbing element provided at the mouth end of the cartridge. The mouthpiece cotton disc 89 mitigates against any large liquid droplets leaving the cartridge through the mouth end.

[0209] A flavour indicator 88 is fitted over 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.

[0210] During manufacture the cartridge can be filled with liquid through an opening in the outer housing provided at the mouth end. Two openings are provided, one for receiving the liquid, the other for venting the air from the liquid reservoir. The mouthpiece cotton disc has corresponding openings, which are sealed by the flavour indicator after the cartridge has been filled, as shown in Figure 2.

Claims

Claims1 . A cartridge for an aerosol-generating system, the cartridge comprising: a housing, the 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 airflow passage; and a heater assembly, the heater assembly extending into or across the airflow passage, 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 passage between the at least one liquid absorbing element and the air outlet; wherein the housing comprises an outer housing and an inner housing, at least a portion of the airflow passage being within the inner housing, and the liquid reservoir being defined between the outer housing and the inner housing; wherein the at least one liquid absorbing element comprises an internal liquid absorbing element, wherein the internal liquid absorbing element is held in a recess defined in the inner housing.

2. A cartridge according to claim 1 , 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 absorbing element is positioned between the heater assembly and the connection end.

3. A cartridge according to claim 1 or claim 2, 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.

4. A cartridge according to any preceding claim , wherein in an initial configuration the liquid reservoir is sealed 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.

5. A cartridge according to claim 4, wherein the inner housing has an engagement surface, wherein the engagement surface of the inner housing is accessible from an exterior of cartridge to allow inner housing to be moved out of the initial position.

6. A cartridge according to claim 5, wherein the engagement surface is circumscribed by the outer housing, preferably such that the engagement surface is accessible only through a connection end of the outer housing.

7. A cartridge according to any preceding claim, wherein the inner housing is generally tubular and has an open end at the air outlet and a closed end opposite the open end, wherein the liquid absorbing element is held in the closed end of the inner housing.

8. A cartridge according to any preceding claim wherein the at least one liquid absorbing element comprises an external liquid absorbing element positioned in a portion of the airflow passage between the inner housing and outer housing.

9. A cartridge according to any preceding claim, comprising a further liquid absorbing element located at the air outlet end of the airflow passage.

10. A cartridge according to any one of the preceding claims, wherein the heating element is a susceptor element.11 . A cartridge according to any one of the preceding claims, wherein the heating element is a mesh heating element configured to wick liquid.

12. A cartridge according to any one of the preceding claims, wherein the at least one liquid absorbing element comprises one or more open celled porous members.

13. A cartridge according to any one of the preceding claims, further comprising a porous member between the liquid reservoir and the heater assembly.

14. A cartridge according to claim 13, wherein the porous member is positioned between the inner housing and the outer housing of the cartridge.

15. An aerosol generating system comprising a cartridge according to any one of the preceding examples and a device, in use the cartridge being fixed to the device, the device comprising a power supply.

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