The present disclosure relates to a cartridge for use with an aerosol-generating device. The present disclosure further relates to an aerosol-generating system comprising the cartridge and the aerosol-generating device.

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 aerosol-forming 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.

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 aerosol-forming substrate may be comprised in a liquid storage portion and may be delivered to the heating element via a capillary component. The liquid storage portion may form part of a replaceable or refillable cartridge. The cartridge may comprise manually removable liquid storage portion sealing means, for example a removable sealing cap or a disposable sealing foil, to avoid leakage of aerosol-forming substrate prior to use.

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 avoid separate disposable sealing means. It would be desirable to provide a cartridge for an aerosol-generating device which may allow for a user to easily visually verify whether the cartridge is a fresh cartridge or a used cartridge. It would be desirable to provide a cartridge of low complexity. It would be desirable to provide a cartridge with low manufacturing costs. It would be desirable to provide a cartridge with low environmental impact. It would be desirable to provide a cartridge for an aerosol-generating device which may improve the user experience. It would be desirable to provide a cartridge for an aerosol-generating device which may be more comfortably handled by a user.

According to an embodiment of the invention there is provided a cartridge for use with an aerosol-generating device. The cartridge may comprise a tubular reservoir for holding a liquid aerosol-forming substrate. An inner sidewall of the tubular reservoir may coaxially circumscribe a hollow inner channel. The cartridge may comprise a movable sealing element arranged within the hollow inner channel. The movable sealing element may be axially movable along the hollow inner channel from a first position to fluidly isolate the reservoir from the hollow inner channel to a second position to fluidly connect the reservoir with the hollow inner channel.

According to an embodiment of the invention there is provided a cartridge for use with an aerosol-generating device. The cartridge comprises a tubular reservoir for holding a liquid aerosol-forming substrate. An inner sidewall of the tubular reservoir coaxially circumscribes a hollow inner channel. The cartridge comprises a movable sealing element arranged within the hollow inner channel. The movable sealing element is axially movable along the hollow inner channel from a first position to fluidly isolate the reservoir from the hollow inner channel to a second position to fluidly connect the reservoir with the hollow inner channel.

A cartridge is provided which may reduce or avoid leakage of aerosol-forming substrate.

A cartridge is provided which may avoid separate disposable sealing means. The cartridge may have low environmental impact. The cartridge may be of low complexity. The cartridge may have low manufacturing costs.

For a fresh cartridge prior to use, the movable sealing element may be in the first position. A cartridge is provided which may allow for a user to easily visually verify whether the cartridge is a fresh cartridge or a used cartridge.

A cartridge which may improve the user experience is provided. A cartridge which may be more comfortably handled by a user is provided.

In the first position, the movable sealing element may function as a fluid impermeable seal between the reservoir and the hollow inner channel such that liquid contained in the reservoir is prevented from entering the hollow inner channel. The first position may be a preuse position.

In the second position, the movable sealing element may be positioned not to block a fluid pathway between the reservoir and the hollow inner channel such that liquid may migrate from the reservoir towards the hollow inner channel.

The movable sealing element may be configured to automatically move from the first position to the second position when the cartridge is being attached to the aerosol-generating device. The movable sealing element may be configured to be automatically moved from the first position to the second position by an elongate element of an aerosol-generating device, when the elongate element is inserted into the hollow inner channel.

The movable sealing element may be configured to be moved from the first position to the second position by means of a cylindrical element of the aerosol-generating device when the cylindrical element is being inserted into the hollow inner channel of the cartridge.

The inner sidewall of the tubular reservoir coaxially circumscribing the hollow inner channel may comprise a fluid permeable wall portion. The movable sealing element may be configured to seal the fluid permeable wall portion when the movable sealing element is in the first position.

The fluid permeable wall portion may comprise one or more through-holes or perforations of the sidewall. Liquid may migrate through the through-holes or perforations from the reservoir towards the hollow inner channel when the movable sealing element has moved from the first position into the second position. The fluid permeable wall may be made of a non-porous material and may comprise perforations or through-holes.

The fluid permeable wall portion may comprise a fluid permeable material. Liquid may migrate through the fluid permeable material from the reservoir towards the hollow inner channel when the movable sealing element has moved from the first position into the second position.

The fluid permeable material may be a porous material. The porosity of the porous material may be between 25% and 80%, more preferably between 55% and 75%, more preferably between 65% and 75%.

As used herein, the term ‘porosity’ is defined as the percentage of a unit volume which is void of material. The porosity may be derived using standard method and equation giving a decimal value for porosity. Knowing the pore volume of a defined volume of material (Vp) and its total volume (Vt), porosity (Pt) is given by the ratio Vp / Vt. To express porosity as a percent, that decimal is simply multiplied by 100%. For example, Pt = 0.51 , therefore 0.51 x 100% = 51%.

The porous material may be a ceramic- based material. The porous material may be a graphite-based material.

The porous material may be generally the same material as also used for non-fluid- permeable wall portions of the tubular reservoir of the cartridge. This may provide a simple design. The porous material may be polymeric compound material. The porous material may be polymeric compound material and the non-fluid-permeable wall portions may be made from polymeric compound material. The porosity of the porous material may be obtained by a set of openings or micro-holes, preferably in a defined arrangement and number, to obtain the designed porosity range.

The porous material may comprise or may be made of other porous material, for example porous ceramic-based material. The porous material of the fluid permeable wall portion, for example porous ceramic-based material, may be over-molded in a polymeric non-fluid-permeable wall portion.

The ceramic-based porous material may be based on pure silica. For example, the ceramic-based porous material may be based on pure silica as usually used to obtain porous silica ceramics industrially produced from silica spinning solutions, where silica particles are introduced by electrospinning, and a sintering (temperatures of about 1000 °C to 1200 °C) is then applied to obtain the final desired geometrical shape and size, also obtaining the desired porosity. The porosity of the sintered material may be adjusted by changing the range of the size of the introduced silica particles. This may enable controlling the desired porosity after sintering.

Other materials may be used to produce the porous material, for example ceramic compounds using one or more of zirconium, titanium, tantalum, tungsten, and molybdenum, for example in several forms as boride, nitride, and carbide, of those.

The movable sealing element may be a slidable sealing element arranged to slide along the inner sidewall of the tubular reservoir.

The movable sealing element may remain coupled to the rest of the cartridge in both the first and second positions. The coupling may be established by a frictional fit of the movable sealing element within the hollow inner channel.

A proximal end of the cartridge may be configured as a mouthpiece.

The hollow inner channel may function as an airflow channel. The proximal end of the cartridge may comprise an air outlet in fluid connection with the hollow inner channel.

The hollow inner channel may extend along a longitudinal center axis between a proximal end and a distal end of the cartridge.

A distal portion of the cartridge may have a circular cross-section. A proximal portion of the cartridge may have an oval cross-section. An oval proximal portion may provide a comfortable mouthpiece shape for a user.

A diameter of the hollow inner channel may increase towards the proximal end of the cartridge. By a larger diameter an expansion chamber may be provided.

The cartridge may be releasably attachable to the aerosol-generating device. A distal end of the cartridge may comprise connection means configured to be releasably connectable to an aerosol-generating device. The connection means may be an annular connecting port. The connection means may be a male part or a female part of a malefemale coupling, and the respective other part may be provided at the aerosol-generating device. The connection means may form a press-fit or form-fit coupling with a respective other part of the aerosol-generating device. The connection means may form a screw connection or a bayonet connection with a respective other part of the aerosol-generating device. The connection means may comprise a magnetic coupling.

The movable sealing element may comprise polymeric material. The polymeric material may be elastomeric material. The elastomeric material may be selected from one or more of PTFE, Nitrile, Neoprene, EPDM Rubber, and Fluorocarbon. A diameter of the hollow inner channel may be between 2.5 millimeters and 6 millimeters, preferably between 3.0 millimeters and 5.5 millimeters, more preferably between 3.0 millimeters and 4.2 millimeters.

A length of the movable sealing element may be between 3.0 millimeters and 6 millimeters, preferably between 3.5 millimeters and 5.5 millimeters, more preferably between 4.0 millimeters and 5.0 millimeters.

An outer diameter of the movable sealing element may be between 2.5 millimeters and 4.5 millimeters, preferably between 3.0 millimeters and 4.0 millimeters, more preferably between 3.25 millimeters and 3.75 millimeters.

The movable sealing element may be a tubular movable sealing element. The tubular movable sealing element may comprise an inner hollow channel of the tubular movable sealing element.

A diameter of the inner hollow channel of the tubular movable sealing element may be between 1.0 millimeter and 3.0 millimeters, preferably between 1.5 millimeters and 2.5 millimeters, more preferably between 1.8 millimeters and 2.3 millimeters.

A cross-section of the inner hollow channel of the tubular movable sealing element may vary along an axial direction of the movable sealing element. A diameter of the inner hollow channel of the tubular movable sealing element may be reduced at a position along an axial direction of the movable sealing element. By varying the diameter of at least a portion of the inner hollow channel of the movable sealing element, the airflow may be controlled. By varying the diameter of the inner hollow channel of the movable sealing element, the retention to draw of the aerosol-generating system may be varied. For example, a reduction of the diameter of a portion of the inner hollow channel of the movable sealing element may restrict the airflow through the inner channel. Thereby, the retention to draw may be increased. A flexible aerosol-generating system may be provided. Different cartridges with different retentions to draw may be provided. A user may choose between different cartridges with different resistances to draw. A user may choose different resistances to draw without the need to buy a new aerosol-generating device.

A reduced diameter of the inner hollow channel of the movable sealing element may create a Venturi effect. When the cartridge is connected to an aerosol-generating device, the movable sealing element may be in the second position and may be located downstream of a heating element of the aerosol-generating device. The reduced diameter may create a Venturi effect to expand the aerosol-volume after the evaporation at the heating element. This may lead to a turbulent airflow which may provide a good mixing effect inside the airflow channel. The inner walls of the tubular movable sealing element may be convexly shaped such that a center portion of the inner hollow channel of the tubular movable sealing element has a reduced diameter with respect to proximal and distal end portions of the inner hollow channel of the tubular movable sealing element.

A reduced diameter of the center portion of the inner hollow channel of the tubular movable sealing element may be between 0.4 millimeter and 1.0 millimeter, preferably between 0.6 millimeter and 0.8 millimeter.

The movable sealing element may be securely held within the hollow inner channel by being friction-fitted to the inner sidewall of the tubular reservoir.

A force needed to move the movable sealing element from the first position into the second position may be between 1 Newton and 5 Newton, preferably between 1 Newton and 3 Newton.

The cartridge may be configured such that the movable sealing element remains in the second position when the cartridge is detached from the aerosol-generating device. The cartridge may be configured such that the movement of the movable sealing element from the first position into the second position is irreversible.

The cartridge may be configured such that the cartridge does not comprise a heating element.

The cartridge may be refillable. The cartridge may be disposable.

According to an embodiment of the invention there is provided an aerosol-generating system comprising a cartridge as described herein and an aerosol-generating device. The aerosol-generating device may comprise an electric heating element. At least a portion of the electric heating element may be arranged to be inserted into the hollow inner channel of the cartridge.

The electric heating element may comprise a susceptor arrangement coaxially circumscribing an inner airflow channel, and an inductor coil coaxially circumscribing the susceptor arrangement. The aerosol-generating device may further comprise a tubular cavity extending coaxially between the susceptor arrangement and the inductor coil and being arranged for insertion of a distal portion of the cartridge into the cavity. The aerosolgenerating system may be arranged such that the hollow inner channel of the cartridge coaxially circumscribes at least a portion of the susceptor arrangement when the distal portion of the cartridge is inserted into the cavity.

The susceptor arrangement may comprise an inner airflow channel extending along a longitudinal center axis between a proximal end and a distal end of the susceptor arrangement. The aerosol-generating device may comprise an air inlet in fluid connection with the inner airflow channel of the susceptor arrangement. The susceptor arrangement may comprise an outer tubular susceptor element coaxially circumscribing the inner airflow channel. At least a portion of a wall of the tubular susceptor element may comprise a fluid permeable material.

When the cartridge is inserted into the cavity, the movable sealing element may be automatically moved from the first position into the second position by the tubular susceptor element. Thereby, a fluid connection may be established between the reservoir and the fluid permeable portion of the wall of the tubular susceptor element. During insertion of the cartridge into the cavity, the tubular susceptor element may physically contact and push the movable sealing element from the first position into the second position.

The susceptor arrangement may comprise a tubular liquid-retaining element coaxially circumscribing at least a portion of the inner airflow channel. The outer tubular susceptor element of the susceptor arrangement may coaxially circumscribe the inner airflow channel and the liquid-retaining element.

At least a portion of a wall of the tubular susceptor element may be fluid permeable. The susceptor element may comprise a porous material. The fluid permeable wall of the susceptor element may be made of a porous material. The fluid permeable wall of the susceptor element may comprise perforations. The fluid permeable wall of the susceptor element may be made of a non-porous material and comprise perforations.

The susceptor element may comprise a carbon-based material. The susceptor element may comprise a porous carbon-based material. The porous carbon-based material may comprise magnetic graphene. The porous carbon-based material may comprise magnetic carbon-based materials, for example one or more of irradiated graphite, nanocarbons, fullerenes, oxygen-containing carbons and graphene with point defects. The porous carbon-based material may comprise one or more carbon-based compounds with metal structural dispersion, for example a FesC -graphitized carbon black (mGCB) composite which can be used to produce porous sheets, perforated, or compacted granulated structures to obtain the desired porosity.

The susceptor element may comprise one or both of a metal and an alloy. The susceptor element may comprise a ferromagnetic alloy material. The ferromagnetic alloy material may be perforated to provide a desired porosity. The alloy material may be ferromagnetic inox alloy.

The susceptor element may comprise at least one ferromagnetic stainless steel alloy. The susceptor element may comprise 304 stainless steel. The susceptor element may comprise one or more ferritic stainless steel alloys, for example those which are ferromagnetic and are used as magnetic components such as solenoid cores, pole pieces and return paths. The susceptor element may comprise a 410 stainless steel alloy. The liquid-retaining element may comprise cotton. The liquid-retaining element may be made of cotton.

The liquid-retaining element may be a porous element. The liquid-retaining element may be capable of absorbing liquid aerosol-forming substrate. The liquid-retaining element may comprise a capillary material. The capillary material may have a fibrous or spongy structure. The capillary material preferably comprises a bundle of capillaries. For example, the capillary material may comprise a plurality of fibres or threads or other fine bore tubes. The fibres or threads may be generally aligned to convey liquid from the distal part of the liquid-retaining element to the proximal part of the liquid-retaining element. Alternatively, the capillary material may comprise sponge-like or foam-like material. The structure of the capillary material may form a plurality of small bores or tubes, through which the liquid can be transported by capillary action. The capillary material may comprise any suitable material or combination of materials. Examples of suitable materials are a sponge or foam material, ceramic- or graphite-based materials in the form of fibres or sintered powders, foamed metal or plastics materials, a fibrous material, for example made of spun or extruded fibres, such as cellulose acetate, polyester, or bonded polyolefin, polyethylene, ethylene or polypropylene fibres, nylon fibres or ceramic. The capillary material may have any suitable capillarity and porosity so as to be used with different liquid physical properties. The liquid has physical properties, including but not limited to viscosity, surface tension, density, thermal conductivity, boiling point and vapour pressure, which allow the liquid to be transported through the capillary material by capillary action. The capillary material may be configured to convey the aerosol-forming substrate to the proximal part of the liquid-retaining element and to the susceptor element. The capillary material may extend into interstices in the susceptor element.

As used herein, the term ‘aerosol-forming substrate’ relates to a substrate capable of releasing volatile compounds that can form an aerosol or a vapor. Such volatile compounds may be released by heating the aerosol-forming substrate. The aerosol-forming substrate may be in liquid form. The terms ‘aerosol’ and ‘vapor’ are used synonymously.

The aerosol-forming substrate may be part of a cartridge. The aerosol-forming substrate may be part of the liquid held in the liquid storage portion of the cartridge. The liquid storage portion may contain a liquid aerosol-forming substrate.

Preferably, a liquid nicotine or flavor/flavorant containing aerosol-forming substrate may be employed in the liquid storage portion of the cartridge.

The aerosol-forming substrate may comprise nicotine.

The aerosol-forming substrate may comprise at least one aerosol-former. 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 device. Suitable aerosol-formers are well known in the art and include, but are not limited to: polyhydric alcohols, such as triethylene glycol, 1 ,3-butanediol and glycerine; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Preferred aerosol formers are polyhydric alcohols or mixtures thereof, such as triethylene glycol, 1 , 3-butanediol. Preferably, the aerosol former is glycerine.

As used herein, the term ‘cartridge’ refers to an article comprising an aerosol-forming substrate that is capable of releasing volatile compounds that can form an aerosol. For example, a cartridge may be an article that generates an aerosol that is directly inhalable by the user drawing or puffing on a mouthpiece at a proximal or user-end of the device or at a mouthpiece of the cartridge itself. A cartridge may be disposable. A cartridge may be reusable. A cartridge may be refillable. The cartridge may be insertable into a cavity of the aerosol-generating device.

As used herein, the term ‘liquid storage portion’ refers to a storage portion comprising an aerosol-forming substrate that is capable of releasing volatile compounds that can form an aerosol. The liquid storage portion may be configured as a container or a reservoir for storing the liquid aerosol-forming substrate.

The liquid storage portion may be configured as a replaceable tank or container. The liquid storage portion may be any suitable shape and size. For example, the liquid storage portion may be substantially cylindrical. The cross-section of the liquid storage portion may, for example, be substantially circular, elliptical, square or rectangular. The liquid storage portion may form part of the cartridge.

As used herein, the term ‘aerosol-generating device’ refers to a device that interacts with one or both of an aerosol-generating article and a cartridge to generate an aerosol.

As used herein, the term ‘aerosol-generating system’ refers to the combination of an aerosol-generating device with one or both of a cartridge and an aerosol-generating article. In the system, the aerosol-generating device and one or both of the aerosol-generating article and the cartridge cooperate to generate a respirable aerosol.

Preferably, the aerosol-generating device is portable. The aerosol-generating device may have a size comparable to a conventional cigar or cigarette. The device may be an electrically operated smoking device. The device may be a handheld aerosol-generating device. The aerosol-generating device may have a total length between 30 millimeters and 150 millimeters. The aerosol-generating device may have an external diameter between 5 millimeters and 30 millimeters. The aerosol-generating device may comprise a housing. The housing may be elongate. The housing 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. Preferably, the material is light and non-brittle.

The housing may comprise at least one air inlet. The housing may comprise more than one air inlet.

The aerosol-generating device may comprise a heating element. The heating element may comprise at least one inductor coil for inductively heating one or more susceptors.

Operation of the heating element may be triggered by a puff detection system. Alternatively, the heating element may be triggered by pressing an on-off button, held for the duration of the user’s puff. The puff detection system may be provided as a sensor, which may be configured as an airflow sensor to measure the airflow rate. The airflow rate is a parameter characterizing the amount of air that is drawn through the airflow path of the aerosol-generating device per time by the user. The initiation of the puff may be detected by the airflow sensor when the airflow exceeds a predetermined threshold. Initiation may also be detected upon a user activating a button. The sensor may also be configured as a pressure sensor.

The aerosol-generating device may include a user interface to activate the aerosolgenerating device, for example a button to initiate heating of the aerosol-generating device or a display to indicate a state of the aerosol-generating device or of the aerosol-forming substrate.

The aerosol-generating device may include additional components, such as, for example a charging unit for recharging an on-board electric power supply in an electrically operated or electric aerosol-generating device.

As used herein, the term ‘proximal’ refers to a user-end, or mouth-end of the aerosolgenerating device or system or a part or portion thereof, and the term ‘distal’ refers to the end opposite to the proximal end. When referring to the heating chamber, the term ‘proximal’ refers to the region closest to the open end of the cavity and the term ‘distal’ refers to the region closest to the closed end.

As used herein, the terms ‘upstream’ and ‘downstream’ are used to describe the relative positions of components, or portions of components, of the aerosol-generating device in relation to the direction in which a user draws on the aerosol-generating device during use thereof. The term ‘airflow path’ as used herein denotes a channel suitable to transport gaseous media. An airflow path may be used to transport ambient air. An airflow path may be used to transport an aerosol. An airflow path may be used to transport a mixture of air and aerosol.

As used herein, a ‘susceptor’ or ‘susceptor element’ means an element that heats up when subjected to an alternating magnetic field. This may be the result of eddy currents induced in the susceptor element, hysteresis losses, or both eddy currents and hysteresis losses. During use, the susceptor element is located in thermal contact or close thermal proximity with an aerosol-forming substrate received in the aerosol-generating device or cartridge. In this manner, the aerosol-forming substrate is heated by the susceptor such that an aerosol is formed.

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 one or both of the susceptor element of the cartridge, a susceptor of an aerosol-generating device, and a susceptor of an aerosolgenerating article. 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.

The susceptor material may be formed from a single material layer. The single material layer may be a steel layer.

The susceptor material may comprise a non-metallic core with a metal layer disposed on the non-metallic core. For example, the susceptor material may comprise metallic tracks formed on an outer surface of a ceramic core or substrate.

The susceptor material may be formed from a layer of austenitic steel. One or more layers of stainless steel may be arranged on the layer of austenitic steel. For example, the susceptor material may be formed from a layer of austenitic steel having a layer of stainless steel on each of its upper and lower surfaces. The susceptor element may comprise a single susceptor material. The susceptor element may comprise a first susceptor material and a second susceptor material. The first susceptor material may be disposed in intimate physical contact with the second susceptor material. The first and second susceptor materials may be in intimate contact to form a unitary susceptor. In certain embodiments, the first susceptor material is stainless steel and the second susceptor material is nickel. The susceptor element may have a two-layer construction. The susceptor element may be formed from a stainless steel layer and a nickel layer.

Intimate contact between the first susceptor material and the second susceptor material may be made by any suitable means. For example, the second susceptor material may be plated, deposited, coated, clad or welded onto the first susceptor material. Preferred methods include electroplating, galvanic plating and cladding.

The aerosol-generating device may comprise a power supply for powering the heating element. The power supply may comprise a battery. The power supply may be a lithium-ion battery. Alternatively, the power supply may be a nickel-metal hydride battery, a nickel cadmium battery, or a lithium-based battery, for example a lithium-cobalt, a lithium- iron-phosphate, lithium titanate or a lithium-polymer battery. The power supply may require recharging and may have a capacity that enables to store enough energy for one or more usage experiences; for example, the power supply may have sufficient capacity to continuously generate aerosol for a period of around six minutes or for a period of a multiple of six minutes. In another example, the power supply may have sufficient capacity to provide a predetermined number of puffs or discrete activations of the heating element.

The power supply may be a direct current (DC) power supply. In one embodiment, the power supply is a DC power supply having a DC supply voltage in the range of 2.5 Volts to 4.5 Volts and a DC supply current in the range of 1 Amp to 10 Amps (corresponding to a DC power supply in the range of 2.5 Watts to 45 Watts). The aerosol-generating device may advantageously comprise a direct current to alternating current (DC/AC) inverter for converting a DC current supplied by the DC power supply to an alternating current. The DC/AC converter may comprise a Class-D, Class-C or Class-E power amplifier. The AC power output of the DC/AC converter is supplied to the induction coil.

The power supply may be adapted to power an inductor coil and may be configured to operate at high frequency. A Class-E power amplifier is preferable for operating at high frequency. As used herein, the term ‘high frequency oscillating current’ means an oscillating current having a frequency of between 500 kilohertz and 30 megahertz. The high frequency oscillating current may have a frequency of from 1 megahertz to 30 megahertz, preferably from 1 megahertz to 10 megahertz, and more preferably from 5 megahertz to 8 megahertz.

In another embodiment the switching frequency of the power amplifier may be in the lower kHz range, e.g. between 100 kHz and 400 KHz. In the embodiments, where a Class-D or Class-C power amplifier is used, switching frequencies in the lower kHz range are particularly advantageous.

The aerosol-generating device may comprise a controller. The controller may be electrically connected to the inductor coil. The controller may be electrically connected to the first induction coil and to the second induction coil. The controller may be configured to control the electrical current supplied to the induction coil(s), and thus the magnetic field strength generated by the induction coil(s).

The power supply and the controller may be connected to the inductor coil(s).

The controller may be configured to be able to chop the current supply on the input side of the DC/AC converter. This way the power supplied to the inductor coil(s) may be controlled by conventional methods of duty-cycle management.

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.

Example E1: A cartridge for use with an aerosol-generating device, comprising a tubular reservoir for holding a liquid aerosol-forming substrate; an inner sidewall of the tubular reservoir coaxially circumscribing a hollow inner channel; and a movable sealing element arranged within the hollow inner channel and being axially movable along the hollow inner channel from a first position to fluidly isolate the reservoir from the hollow inner channel to a second position to fluidly connect the reservoir with the hollow inner channel.

Example E2: The cartridge according to Example E1, wherein the movable sealing element is configured to automatically move from the first position to the second position when the cartridge is being attached to the aerosol-generating device.

Example E3: The cartridge according to Example E2, wherein the movable sealing element is configured to be moved from the first position to the second position by means of a cylindrical element of the aerosol-generating device when the cylindrical element is being inserted into the hollow inner channel of the cartridge.

Example E4: The cartridge according to any of the preceding examples, wherein the inner sidewall of the tubular reservoir coaxially circumscribing the hollow inner channel comprises a fluid permeable wall portion, and wherein the movable sealing element is configured to seal the fluid permeable wall portion when being in the first position.

Example E5: The cartridge according to Example E4, wherein the fluid permeable wall portion comprises one or more through-holes or perforations of the sidewall. Example E6: The cartridge according to Example E5, wherein the fluid permeable wall portion comprises a fluid permeable material.

Example E7: The cartridge according to Example E6, wherein the fluid permeable material is a porous material, preferably wherein the porosity of the porous material is between 25% and 80%, more preferably between 55% and 75%, more preferably between 65% and 75%.

Example E8: The cartridge according to Example E7, wherein the porous material is a ceramic- or graphite-based material.

Example E9: The cartridge according to any of the preceding examples, wherein the movable sealing element is a slidable sealing element arranged to slide along the inner sidewall of the tubular reservoir.

Example E10: The cartridge according to any of the preceding examples, wherein the movable sealing element remains coupled to the rest of the cartridge in both the first and second positions.

Example E11 : The cartridge according to any of the preceding examples, wherein a proximal end of the cartridge is configured as a mouthpiece.

Example E12: The cartridge according to any of the preceding examples, wherein the hollow inner channel extends along a longitudinal center axis between a proximal end and a distal end of the cartridge.

Example E13: The cartridge according to Example E12, wherein a distal portion of the cartridge has a circular cross-section, and a proximal portion of the cartridge has an oval cross-section.

Example E14: The cartridge according to Example E12 or Example E13, wherein a diameter of the hollow inner channel increases towards the proximal end of the cartridge.

Example E15: The cartridge according to any of the preceding examples, wherein a distal end of the cartridge comprises connection means configured to be releasably connectable to an aerosol-generating device.

Example E16: The cartridge according to any of the preceding examples, wherein the movable sealing element comprises polymeric material, preferably elastomeric material.

Example E17: The cartridge according to Example E16, wherein the movable sealing element comprises elastomeric material, and wherein the elastomeric material is selected from one or more of PTFE, Nitrile, Neoprene, EPDM Rubber, and Fluorocarbon.

Example E18: The cartridge according to any of the preceding examples, wherein a diameter of the hollow inner channel is between 2.5 millimeters and 6 millimeters, preferably between 3.0 millimeters and 5.5 millimeters, more preferably between 3.0 millimeters and 4.2 millimeters. Example E19: The cartridge according to any of the preceding examples, wherein the movable sealing element is a tubular movable sealing element.

Example E20: The cartridge according to Example E19, wherein a cross-section of an inner hollow channel of the tubular movable sealing element varies along an axial direction of the movable sealing element.

Example E21 : The cartridge according to Example E20, wherein the inner walls of the tubular movable sealing element are convexly shaped such that a center portion of the inner hollow channel of the tubular movable sealing element has a reduced diameter with respect to proximal and distal end portions of the inner hollow channel of the tubular movable sealing element.

Example E22: The cartridge according to any of the preceding examples, wherein the movable sealing element is securely held within the hollow inner channel by being friction- fitted to the inner sidewall of the tubular reservoir.

Example E23: The cartridge according to any of the preceding examples, wherein a force needed to move the movable sealing element from the first position into the second position is between 1 Newton and 5 Newton, preferably between 1 Newton and 3 Newton.

Example E24: The cartridge according to any of the preceding examples, wherein the cartridge is configured such that the movable sealing element remains in the second position when the cartridge is detached from the aerosol-generating device.

Example E25: The cartridge according to any of the preceding examples, wherein the cartridge is configured such that the movement of the movable sealing element from the first position into the second position is irreversible.

Example E26: The cartridge according to any of the preceding examples, wherein the cartridge does not comprise a heating element.

Example E27: An aerosol-generating system, comprising the cartridge according to any of the preceding examples; and an aerosol-generating device comprising an electric heating element, wherein at least a portion of the electric heating element is arranged to be inserted into the hollow inner channel of the cartridge.

Example E28: The aerosol-generating system according to Example E27, wherein the electric heating element comprises a susceptor arrangement coaxially circumscribing an inner airflow channel, and an inductor coil coaxially circumscribing the susceptor arrangement, wherein the aerosol-generating device further comprises a tubular cavity extending coaxially between the susceptor arrangement and the inductor coil and being arranged for insertion of a distal portion of the cartridge into the cavity, and wherein the system is arranged such that the hollow inner channel of the cartridge coaxially circumscribes at least a portion of the susceptor arrangement when the distal portion of the cartridge is inserted into the cavity.

Features described in relation to one embodiment may equally be applied to other embodiments of the invention.

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

Fig. 1 shows a cartridge for use with an aerosol-generating device;

Fig. 2a shows a cartridge for use with an aerosol-generating device;

Fig. 2b shows a movable sealing element;

Fig. 3 shows an aerosol-generating device;

Fig. 4 shows an aerosol-generating system; and

Figs. 5a and 5b show an aerosol-generating system.

Fig. 1 shows in cross-sectional view a cartridge 10 for use with an aerosol-generating device, for example for use with the aerosol-generating device 50 of Fig. 3.

The cartridge 10 comprises a tubular reservoir 12 for holding a liquid aerosol-forming substrate. An inner sidewall 14 of the tubular reservoir coaxially circumscribes a hollow inner channel 16. The hollow inner channel 16 extends along a longitudinal center axis between a proximal end and a distal end of the cartridge 10.

A tubular movable sealing element 18 is arranged within the hollow inner channel 16. The movable sealing element 18 is axially movable along the hollow inner channel 16 from a first position to fluidly isolate the reservoir 12 from the hollow inner channel 16 to a second position to fluidly connect the reservoir 12 with the hollow inner channel 16. In Fig. 1, the movable sealing element 18 is in the first position.

The inner sidewall 14 comprises a fluid permeable wall portion 20. The movable sealing element 18 is configured to seal the fluid permeable wall portion 20 when being in the first position. A fluid connection between the reservoir 12 and the hollow inner channel 16 via the fluid permeable wall portion 20 is thus prevented by the movable sealing element 18 being in the first position.

The movable sealing element 18 is a slidable sealing element arranged to slide along the inner sidewall 14 of the tubular reservoir 12. The movable sealing element 18 is arranged to be slid longitudinally along the hollow inner channel 16 of the cartridge 10 when an elongate element of an aerosol-generating device, for example the susceptor arrangement of the aerosol-generating device 50 of Fig. 3, is inserted into the hollow inner channel 16. The tubular movable sealing element 18 is hollow. The hollow inner channel of the movable sealing element 18 is, at both sides thereof, in fluid connection with the hollow inner channel 16 of the cartridge 10. The outer diameter of the tubular movable sealing element 18 is dimensioned such that the tubular movable sealing element 18 is securely held within the hollow inner channel 16 by being friction-fitted to the inner sidewall 14 of the tubular reservoir 12. A proximal end of the cartridge 10 is configured as a mouthpiece 22. The mouthpiece 22 comprises an air outlet 24 in fluid connection with the hollow inner channel 16.

A diameter of the hollow inner channel 16 increases towards the air outlet 24 at the proximal end of the cartridge 10.

A distal end of the cartridge 10 comprises connection means configured to be releasably connectable to an aerosol-generating device. The connection means is provided in form of an annular connecting port 26 for releasably connecting with a corresponding cartridge connecting port of an aerosol-generating device, for example cartridge connecting port 62 of the aerosol-generating device 50 shown in Fig. 3.

The cartridge 10 of Fig. 1 does not comprise a heating element.

Fig. 2a recites the cross-sectional view of the cartridge 10 of Fig. 1. Fig. 2a indicates preferred dimensions of the cartridge 10 of Fig. 1.

Fig. 2b shows the movable sealing element 18 of the cartridge 10 of Fig. 1 in cross- sectional view. Fig. 2b shows preferred dimensions of the movable sealing element 18 of the cartridge 10 of Fig. 1.

Values of the preferred dimensions of Figs. 2A and 2B are listed in the Table below. As shown in Fig. 2B, the cross-section of the hollow inner channel of the movable sealing element 18 varies along an axial direction parallel to a length “L” of the movable sealing element 18. The inner walls of the tubular movable sealing element 18 are convexly shaped such that a center portion of the inner hollow channel of the tubular movable sealing element 18 has a reduced diameter “A” with respect to proximal and distal end portions of the inner hollow channel of the tubular movable sealing element 18 which have a larger diameter “B”.

Fig. 3 shows a subsection of an aerosol-generating device 50 in cross-sectional view. The aerosol-generating device 50 comprises a susceptor arrangement 80 mounted on a support element 52 within a housing 54 of the aerosol-generating device 50.

The susceptor arrangement 80 comprises a tubular susceptor element 82. The tubular susceptor element 82 comprises a fluid permeable intermediate region 84. The tubular susceptor element 82 coaxially circumscribes a tubular liquid-retaining element 86. The tubular liquid-retaining element 86 coaxially circumscribes an inner airflow channel 88 of the susceptor arrangement 80. Sealing elements in form of O-rings 90 are provided on the outside of the tubular susceptor element 82 at positions proximal and distal to the fluid permeable intermediate region 84.

The aerosol-generating device 50 comprises an inductor coil 56 coaxially circumscribing the susceptor arrangement 51. The inductor coil 56 is housed within a casing 58.

The aerosol-generating device 50 comprises a tubular cavity 60 extending coaxially between the susceptor arrangement 80 and the inductor coil 56 and being arranged for insertion of a tubular cartridge 10 into the cavity 60. The aerosol-generating device 50 further comprises an annular cartridge connecting port 62.

The aerosol-generating device 50 comprises an air inlet 64 in fluid connection with the inner airflow channel 88 of the susceptor arrangement 80.

The aerosol-generating device 50 further comprises a controller 66 in wired connection 68 with both the inductor coil 56 and a power supply 70, preferably a rechargeable battery. A distal part of the aerosol-generating device 50 comprising a distal portion of the power supply 70 is cut off and is not fully shown in Fig. 3. Fig. 3 thus shows a subsection of the aerosol-generating device 50.

Fig. 4 shows a cross-sectional view of an aerosol-generating system comprising the aerosol-generating device 50 of Fig. 3 and the cartridge 10 of Fig. 1 in an attached configuration.

The tubular movable sealing element 18 is in the second position in the configuration of Fig. 4. On inserting the proximal portion of the susceptor arrangement 80 into the hollow inner channel 16, the movable sealing element 18 has been pushed by the tubular susceptor element 82 to slide longitudinally along the hollow inner channel 16 in a direction towards the proximal end of the cartridge 10. The movable sealing element 18 being in the second position is therefore no longer covering and sealing the fluid permeable wall portion 20 of the cartridge 10. The fluid permeable intermediate region 84 of the tubular susceptor element 82 of the susceptor arrangement 80 coincides with the fluid permeable wall portion 20 of the cartridge 10. The fluid permeable wall portion 20 coaxially circumscribes the fluid permeable intermediate region 84. Consequently, a liquid aerosol-forming substrate may migrate from the reservoir 12 through the fluid permeable wall portion 20 and towards and into the fluid permeable intermediate region 84 of the tubular susceptor element 82. The O-rings 90 may prevent the liquid aerosol-forming substrate from an uncontrolled migration into the airflow path at positions proximal and distal to the fluid permeable intermediate region 84.

The aerosol-generating system is arranged such that, in the attached configuration of Fig. 4, the hollow inner channel 16 of the cartridge 10 coaxially circumscribes a proximal portion of the susceptor arrangement 80 of the aerosol-generating device 50. A continuous airflow path is established extending from the air inlet 64 via the airflow channel 88, through the inner hollow channel of the tubular movable sealing element 18 and further along the inner hollow channel 16 up to the air outlet 24.

During use, an alternating current applied to the inductor coil 56 induces electric currents in the tubular susceptor element 82. As a consequence, the tubular susceptor element 82 heats up. Heat is distributed to the liquid aerosol-forming substrate within, or in close proximity to the fluid permeable intermediate region 84. In turn, the heated liquid aerosol-forming substrate evaporates. Ambient air entering via air inlet 64 may take up the evaporated substrate which may further condense to form an aerosol on the way towards the air outlet 24, where the aerosol may be inhaled by a user.

The inner walls of the tubular movable sealing element 18 are convexly shaped such that a center portion of the inner hollow channel of the tubular movable sealing element 18 has a reduced diameter with respect to proximal and distal end portions of the inner hollow channel of the tubular movable sealing element 18. The reduced diameter may create a Venturi effect to expand the aerosol-volume after the tubular movable sealing element 18. This may lead to a turbulent airflow which may provide a good mixing effect inside the hollow inner channel 16.

Liquid droplets of aerosol-forming substrate which have been inadvertently condensed within the airflow path may be taken up the tubular liquid-retaining element 86. The tubular liquid-retaining element 86 may heat up by means of thermal transfer from the tubular susceptor element 82. Thereby, inadvertently condensed aerosol-forming substrate which has been taken up by the liquid-retaining element 86 may eventually be evaporated and participate in aerosol-formation.

Figs. 5a and 5b show an aerosol-generating system in perspective views. The cartridge 10 is releasably attachable to the aerosol-generating device 50. The cartridge 10 may be the cartridge 10 of the embodiment of Fig. 1. The aerosol-generating device 50 may be the aerosol-generating device 50 of the embodiment of Fig. 3. Fig. 5a shows the cartridge 10 and the aerosol-generating device 50 in a detached configuration. Fig. 5b shows the attached configuration where the cartridge 10 is connected to the aerosol-generating device 50.