WO2023174686A1

WO2023174686A1 - A cartridge for a vapour generating device

Info

Publication number: WO2023174686A1
Application number: PCT/EP2023/055136
Authority: WO
Inventors: Daniel Vanko; Martin KOSA; Alec WRIGHT
Original assignee: Jt International Sa
Priority date: 2022-03-14
Filing date: 2023-03-01
Publication date: 2023-09-21

Abstract

A cartridge (10) for a vapour generating device (100). The cartridge (10) comprises a liquid store (16) for containing a vapour generating liquid. The cartridge further comprises a vapour generating unit (12). The vapour generating unit (12) comprises a vaporisation device (18). The vaporisation device (18) includes a heating element (20). The heating element (20) comprises an inductively heatable susceptor (22). The vapour generating unit (12) further comprises a liquid transfer element (24) arranged to hold and transfer vapour generating liquid from the liquid store (16) to the vaporisation device (18) by capillary action. The inductively heatable susceptor (22) is arranged in thermal proximity to the liquid transfer element (24) to heat and vaporise the vapour generating liquid held and transferred to the vaporisation device (18) by the liquid transfer element (24). The cartridge further comprises a cup (26) defining an airflow guide (28).

Description

A CARTRIDGE FOR A VAPOUR GENERATING DEVICE

Technical Field

The present disclosure relates generally to a cartridge for a vapour generating device configured to heat a vapour generating liquid to generate a vapour which cools and condenses to form an aerosol for inhalation by a user of the device.

Technical Background

The term vapour generating device (or more commonly electronic cigarette or e-cigarette) refers to a handheld electronic device that is intended to simulate the feeling or experience of smoking tobacco in a traditional cigarette. Electronic cigarettes work by causing a vapour generating liquid (or so called “e-liquid”) to be heated to generate a vapour that cools and condenses to form an aerosol which is then inhaled by the user.

Some vapour generating devices use induction heating to heat the vapor generating liquid. Such vapour generating devices employ an electromagnetic field generator such as an induction coil to generate an alternating electromagnetic field that couples with, and inductively heats, an inductively heatable susceptor. The vapour generating liquid can be transferred from a liquid store by a liquid transfer element, such as a wick, and is heated and vaporised by heat transferred from the inductively heatable susceptor, resulting in the generation of a vapour that cools and condenses to form an aerosol which is then inhaled by the user.

The vaporisation of the vapour generating liquid may be facilitated by the addition of air from the surrounding environment. However, current designs are not configured to provide for an optimum airflow to ensure vapour is most efficiently generated.

There is, therefore, a need to address this shortcoming.

Summary of the Disclosure

According to a first aspect of the present disclosure, there is provided a cartridge for a vapour generating device, wherein the cartridge comprises: a liquid store for containing a vapour generating liquid; a vapour generating unit, the vapour generating unit comprising: a vaporisation device including a heating element comprising an inductively heatable susceptor; and a liquid transfer element arranged to hold and transfer vapour generating liquid from the liquid store to the vaporisation device by capillary action, wherein the inductively heatable susceptor is arranged in thermal proximity to the liquid transfer element to heat and vaporise the vapour generating liquid held and transferred to the vaporisation device by the liquid transfer element, the cartridge further comprising: a cup defining an airflow guide, wherein the vapour generating unit is disposed in the interior of the cup; and at least two air inlets through which air is flowable in use from the surrounding environment through a corresponding number of aligned airflow channels into the interior of the cup to flow over the inductively heatable susceptor.

Air flowing through the at least two air inlets and corresponding number of aligned airflow channels into the interior of the cup is distributed uniformly over the surface of the inductively heatable susceptor, in turn ensuring vapour is efficiently generated.

The liquid transfer element may be positioned outside an inner volume of the liquid store, for example beneath the liquid store. This allows the delivery of liquid to the liquid transfer element to be carefully controlled whilst minimising heat transfer from the liquid transfer element to the vapour generating liquid in the liquid store.

The cartridge may comprise at least three air inlets, or at least six air inlets. This further improves the distribution of airflow uniformly over the surface of the inductively heatable susceptor, which in turn further improves the efficiency of vapour generation. The cartridge may comprise from 2 to 12 air inlets, or preferably from 3 to 10 air inlets, or most preferably from 6 to 8 air inlets.

Possibly, the liquid transfer element comprises a hollow core and a base, wherein the hollow core defines a vaporisation chamber, wherein the base comprises at least one indentation which engages with the cup, wherein the at least one indentation is configured such that an airflow path is defined for allowing air to flow from the interior of the cup into the vaporisation chamber. The base of the liquid transfer element may comprise a plurality of indentations. The liquid transfer element may comprise a porous ceramic.

The airflow channels may have a generally radial configuration around the interior of the cup. The airflow channels may be uniformly spaced around the interior of the cup. This further improves the distribution of airflow uniformly over the surface of the inductively heatable susceptor, which in turn further improves the efficiency of vapour generation.

Each of the airflow channels may extend at an angle through a body of the cup into the interior of the cup such that in use air flows through each airflow channel into the interior of the cup at an angle. The angled arrangement of the airflow channels causes air entering the interior of the cup in use to create a vortex, i.e., a spinning or rotating stream, which flows radially over the surface of the inductively heatable susceptor. Accordingly, in use air circulates around the inductively heatable susceptor. This further improves the distribution of airflow uniformly over the surface of the inductively heatable susceptor, which in turn further improves the efficiency of vapour generation. Furthermore, the possibility of undesirable condensation of vapours is reduced because the air vortex created limits the formation of areas of non-moving air. Furthermore, circulation of air causes heat to be transferred away from an outer surface of the cartridge. Circulation of air over the inductively heatable susceptor in use warms the air before it contacts vapours generated, improving efficiency.

The airflow channels may extend into the interior of the cup adjacent the liquid store such that in use air flowing into the interior of the cup limits thermal energy transfer from the vapour generating unit to the liquid store. This arrangement interrupts the undesirable thermal bridge otherwise created in use between the inductively heatable susceptor and/or liquid transfer element of the vapour generating unit and the liquid store by causing cool air to be directed to this area.

The liquid transfer element may include a radially outer circumferential surface. The inductively heatable susceptor may include a radially inner circumferential surface and a radially outer circumferential surface. The inductively heatable susceptor may extend around the radially outer circumferential surface of the liquid transfer element. The inductively heatable susceptor may surround the liquid transfer element. The radially inner circumferential surface of the inductively heatable susceptor may contact the radially outer circumferential surface of the liquid transfer element. By surrounding the radially outer circumferential surface of the liquid transfer element with the inductively heatable susceptor, an efficient and uniform transfer of heat, e.g., by conduction, from the inductively heatable susceptor to the liquid transfer element is achieved so that “hot spots” and “cold spots” are avoided. This in turn ensures that a sufficient amount of vapour is generated during use.

The cup may include an interior surface. The inductively heatable susceptor, and more particularly the radially outer circumferential surface of the inductively heatable susceptor, may be spaced apart from the interior surface of the cup to define an airflow path therebetween. Thus, air is flowable through the at least two air inlets in use from the surrounding environment through a corresponding number of aligned airflow channels into the interior of the cup along the airflow path to flow over the radially outer circumferential surface of the inductively heatable susceptor. This arrangement provides a gap in the interior of the cup which ensures that air can flow across the entire radially outer circumferential surface of the inductively heatable susceptor.

The cup may be substantially cylindrical.

The inductively heatable susceptor may be substantially cylindrical, oval or conical. A substantially cylindrical shaped, oval shaped or conical shaped susceptor geometry provides for a strong electromagnetic coupling with the generated electromagnetic field and a uniform transfer of heat to the liquid transfer element.

The inductively heatable susceptor may be positioned beneath the liquid store. An advantage of this arrangement is that it enables a strong electromagnetic coupling to be achieved with a generated electromagnetic field during use.

Possibly, a vapour outlet channel is fluidly connected to a mouthpiece, wherein the mouthpiece comprises a thermally insulating material. This arrangement limits heat loss.

According to a second aspect of the present disclosure, there is provided a vapour generating system comprising a vapour generating device and a cartridge according to any of the above paragraphs. Brief Description of the Drawings

Figure 1 is an exploded perspective view of a cartridge for use with a vapour generating device; Figure 2a is a diagrammatic perspective view of a part of the cartridge of Figure 1;

Figure 2b is a diagrammatic perspective view of the part of Figure 2a but showing an indication of airflow in use; and

Figure 3 is a diagrammatic view of a vapour generating system comprising a vapour generating device and a cartridge.

Detailed Description of Embodiments

Embodiments of the present disclosure will now be described by way of example only and with reference to the accompanying drawings.

Referring initially to Figures 1 and 2a, there is shown a cartridge 10 according to the present disclosure. The cartridge 10 is configured to be used with a vapour generating device 100 as shown diagrammatically in Figure 3. The cartridge 10 and the vapour generating device 100 together form a vapour generating system 110. Accordingly, the present disclosure also provides a vapour generating system 110 comprising a vapour generating device 100 and a cartridge 10.

The vapour generating device 100 may be elongate and have a substantially cylindrical shape which resembles a cigarette or cigar. Other shapes are, however, entirely within the scope of the present disclosure.

The term vapour generating device 100 (or more commonly electronic cigarette or e-cigarette) refers to a handheld electronic device that is intended to simulate the feeling or experience of smoking tobacco in a traditional cigarette. Electronic cigarettes work by causing a vapour generating liquid to be heated to generate a vapour that cools and condenses to form an aerosol which is then inhaled by the user. Accordingly, using e-cigarettes is also sometimes referred to as “vaping”. Vapour generating liquid is sometimes referred to as e-liquid.

In general terms, a vapour is a substance in the gas phase at a temperature lower than its critical temperature, which means that the vapour can be condensed to a liquid by increasing its pressure without reducing the temperature, whereas an aerosol is a suspension of fine solid particles or liquid droplets, in air or another gas. It should, however, be noted that the terms ‘aerosol’ and ‘vapour’ may be used interchangeably in this specification, particularly with regard to the form of the inhalable medium that is generated for inhalation by a user.

The vapour generating liquid may comprise polyhydric alcohols and mixtures thereof such as glycerine or propylene glycol. The vapour generating liquid may contain nicotine. The vapour generating liquid may also comprise flavourings such as e.g., tobacco, menthol or fruit flavour.

The cartridge 10 comprises a housing 14 having a proximal end 15 and a distal end 17. The proximal end 15 constitutes a mouthpiece 54, i.e., a mouthpiece end, configured for being introduced directly into a user's mouth and may, therefore, also be designated as the mouth end. The mouthpiece 54 provides the ability for a user to easily inhale aerosol generated by the vapour generating device 100. In some examples, the mouthpiece 54 comprises a thermally insulating material. This arrangement limits heat loss.

The cartridge 10 comprises a liquid store 16 for containing, i.e., for holding or storing, a vapour generating liquid. Accordingly, the liquid store 16 is configured for containing therein a vapour generating liquid.

The liquid store 16 may extend generally between the proximal (mouth) end 15 and the distal end 17. The cartridge 10 comprises a vapour outlet channel 52. The vapour outlet channel 52 is fluidly connected to the mouthpiece 54. The liquid store 16 may surround, and coextend with, the vapour outlet channel 52.

As illustrated in Figure 3, in the illustrated example the vapour generating device 100 includes a controller 56. The vapour generating device 100 may include a user interface 58 for controlling the operation of the vapour generating device 100 via the controller 56 and/or for displaying information. In some examples, the user interface 58 may be comprised in a separate device such as a mobile device.

The controller 56 may be configured to detect the initiation of use of the vapour generating device 100 in response to a user input, such as a button press to activate the vapour generating device 100, or in response to a detected airflow through the vapour generating device 100. As will be understood by one of ordinary skill in the art, an airflow through the vapour generating device 100 is indicative of a user inhalation or ‘puff. The vapour generating device 100 may, for example, include a puff detector (not shown), such as an airflow sensor, to detect an airflow through the vapour generating device 100.

The controller 56 includes electronic circuitry 60. The vapour generating device 100 includes a power source 62, such as a battery. The power source 62 and the electronic circuitry 60 may be configured to operate at a high frequency. The power source 62 and the electronic circuitry 60 may be configured to operate at a frequency of between approximately 80 kHz and 500 kHz, possibly between approximately 150 kHz and 250 kHz, and possibly at approximately 200 kHz. The power source 62 and the electronic circuitry 60 could be configured to operate at a higher frequency, for example in the MHz range, if required.

The cartridge 10 may be releasably connectable to the vapour generating device 100 by a releasable connection. The releasable connection can, for example, be a snap-fit connection or alternatively, a magnetic connection, a threaded connection or a bayonet connection. Accordingly, after the vapour generating liquid in the liquid store 16 of the cartridge 10 has been depleted, the cartridge 10 can be disconnected from the vapour generating device 100 and a replacement cartridge 10 can then be connected in its place, to allow further use of the vapour generating device 100. The cartridge 10 may be disposable. Alternatively, in some examples the cartridge 10 may be re-filled with vapour generating liquid so that the cartridge 10 can be re-used.

The cartridge 10 comprises a vapour generating unit 12. The vapour generating unit 12 comprises a vaporisation device 18 and a liquid transfer element 24. The vaporisation device 18 includes a heating element 20, i.e., a heater 20, to produce vapour from the vapour generating liquid contained in the liquid store 16.

The liquid transfer element 24 is arranged to hold and transfer vapour generating liquid from the liquid store 16 to the vaporisation device 18 by capillary action. The liquid transfer element 24 is positioned outside the inner volume of the liquid store 16, and more particularly beneath the liquid store 16. An advantage of this arrangement is that it allows the delivery of liquid to the liquid transfer element 24 to be carefully controlled whilst minimising heat transfer from the liquid transfer element 24 to the vapour generating liquid in the liquid store 16. The heating element 20 comprises an inductively heatable susceptor 22. The inductively heatable susceptor 22 is arranged coaxially with respect to a central longitudinal axis of the cartridge 10.

In the illustrated example, the inductively heatable susceptor 22 comprises a susceptor tube. In other examples, the inductively heatable susceptor 22 may comprise a susceptor ring or susceptor rings. The susceptor rings may be spaced along the central longitudinal axis of the cartridge 10.

The inductively heatable susceptor 22 may have athickness up to 150 pm, preferably may have a thickness from 30 pm to 150 pm, more preferably may have athickness from 100 pm to 150 pm, or most preferably may have a thickness of 100 pm. An inductively heatable susceptor 22 having these thickness dimensions may be particularly suitable for being inductively heated during use of the cartridge 10 with a vapour generating device 100 and may also facilitate manufacture of the cartridge 10.

The inductively heatable susceptor 22 is arranged in thermal proximity to the liquid transfer element 24 to heat and vaporise the vapour generating liquid held and transferred to the vaporisation device 18 by the liquid transfer element 24.

In the illustrated example, the vapour generating device 100 comprises an electromagnetic field generator 50 arranged to generate an alternating electromagnetic field for inductively heating the inductively heatable susceptor 22. The electromagnetic field generator 50 comprises an induction coil 51.

In the illustrated example, the induction coil 51 surrounds the inductively heatable susceptor 22 when the cartridge 10 is connected to the vapour generating device 100. By providing the induction coil 51 as an integral part of the vapour generating device 100, the manufacture and assembly of the cartridge 10 may be simplified. Thus, in the illustrated example the induction coil 51 belongs to the vapour generating device 100 and is brought into proximity with (e.g., to surround) the inductively heatable susceptor 22 when the cartridge 10 is connected to the vapour generating device 100, for instance, via a releasable connection. In other examples, the cartridge 10 comprises an electromagnetic field generator 50. The electromagnetic field generator 50 comprises an induction coil 51. In such examples, the induction coil 51 is an integral part of, and belongs to, the cartridge 10 and surrounds the inductively heatable susceptor 22. An electrical connection is established between the induction coil 51 and the power source 62 of the vapour generating device 100, for example via electrical connectors, when the cartridge 10 is connected to the vapour generating device 100, for instance, via a releasable connection. By providing the induction coil 51 as an integral part of the cartridge 10, an optimum relative positioning of the induction coil 51 and the inductively heatable susceptor 22 may be achieved. This in turn ensures that a strong electromagnetic coupling is achieved between the generated electromagnetic field and the inductively heatable susceptor 22.

As will be understood by one of ordinary skill in the art, when the inductively heatable susceptor 22 is exposed to an alternating and time-varying electromagnetic field generated by the induction coil 51, eddy currents and/or magnetic hysteresis losses are generated in the inductively heatable susceptor 22 causing it to heat up. The heat is transferred from the inductively heatable susceptor 22 to the vapour generating liquid absorbed by the liquid transfer element 24, for example by conduction, radiation and convection, thereby heating and vaporising the vapour generating liquid. This arrangement provides a particularly convenient way to heat and vaporise the vapour generating liquid using induction heating.

In the illustrated example, the induction coil 51 is a helical coil. The induction coil 51 may have a shape which substantially corresponds to the shape of the inductively heatable susceptor 22. The induction coil 51 may be annular. The induction coil 51 may comprise a Litz wire or a Litz cable. It will, however, be understood that other materials could be used.

In the illustrated example, the inductively heatable susceptor 22 is substantially cylindrical. In other examples, the inductively heatable susceptor 22 may be oval shaped, i.e., elliptical, or conical shaped. A substantially cylindrical shaped, oval shaped or conical shaped susceptor geometry provides for a strong electromagnetic coupling with the generated electromagnetic field and a uniform transfer of heat to the liquid transfer element 24. In the illustrated example, the inductively heatable susceptor 22 is positioned outside the inner volume of the liquid store 16, and more particularly beneath the liquid store 16. An advantage of this arrangement is that it enables a strong electromagnetic coupling to be achieved with a generated electromagnetic field during use of the vapour generating system 110.

The inductively heatable susceptor 22 comprises an electrically conductive material, and may comprise one or more, but not limited to, of aluminium, iron, nickel, mild steel, stainless steel, low carbon stainless steel, copper, and alloys thereof, e.g., Nickel Chromium or Nickel Copper.

The electromagnetic field generator 50 may be arranged to operate in use with a fluctuating electromagnetic field having a magnetic flux density of between approximately 20mT and approximately 2.0T at the point of highest concentration.

In some examples, the liquid transfer element 24 comprises a capillary material, such as a porous ceramic material. Accordingly, the liquid transfer element 24 may be a porous liquid transfer element 24. The liquid transfer element 24 includes an outer surface 48 (specifically a radially outer circumferential surface 48) which extends around the entire periphery of the liquid transfer element 24 and which is exposed to an inner space of the liquid store 16. In some examples, a sealing element (not shown) is provided which sealingly closes off the liquid store 16 to retain the vapour generating liquid in the liquid store 16. In such examples, the outer surface 48 of the liquid transfer element 24 is exposed to the inner space of the liquid store 16 by one or more openings or channels (not shown) formed in a sealing element. Vapour generating liquid is thereby absorbed into the liquid transfer element 24 via the outer surface 48 and is conveyed, for example by a wicking action, to the vaporisation device 18 so that it can be heated and vaporised producing a vapour which cools and condenses to form an aerosol which may then be inhaled.

The inductively heatable susceptor 22 is positioned outwardly, e.g., radially outwardly, of the liquid transfer element 24 and is arranged coaxially with respect to the central longitudinal axis of the cartridge 10. This ensures that the inductively heatable susceptor 22 is positioned in the region of highest electromagnetic field concentration and, thus, helps to ensure that a strong electromagnetic coupling is achieved with the generated electromagnetic field. In addition, mechanical stress on the liquid transfer element 24 resulting from thermal expansion of the inductively heatable susceptor 22 is substantially reduced or eliminated because the inductively heatable susceptor 22 expands outwardly, away from the liquid transfer element 24, when it is inductively heated. The risk of damage, e.g., cracking, being caused to the liquid transfer element 24 by the inductively heatable susceptor 22 when it thermally expands is thereby correspondingly substantially reduced or eliminated.

In the illustrated example, the inductively heatable susceptor 22 surrounds the liquid transfer element 24. More particularly, the inductively heatable susceptor 22 fully surrounds the liquid transfer element 24. By surrounding the outer surface 48 of the liquid transfer element 24 with the inductively heatable susceptor 22, an efficient and uniform transfer of heat, e.g., by conduction, from the inductively heatable susceptor 22 to the liquid transfer element 24 is achieved so that “hot spots” and “cold spots” are avoided. This in turn ensures that a sufficient amount of vapour is generated during use.

The inductively heatable susceptor 22 has a radially outer circumferential surface 23 and a radially inner circumferential surface 46 that contacts the radially outer circumferential surface 48 of the liquid transfer element 24. Accordingly, the inductively heatable susceptor 22 is in contact with the liquid transfer element 24. With this arrangement, there is no gap between the radially outer circumferential surface 48 of the liquid transfer element 24 and the radially inner circumferential surface 46 of the inductively heatable susceptor 22. Thus, heat can be readily conducted from the inductively heatable susceptor 22 to the liquid transfer element 24 thereby improving vapour generation and energy efficiency.

The axial length of the inductively heatable susceptor 22 is less than the axial length of the outer surface 48 of the liquid transfer element 24. The term “axial length” means a length in the direction of the longitudinal axis of the cartridge 10.

The cartridge 10 further comprises a cup 26 defining an airflow guide 28. The cup 26 is substantially cylindrical in the illustrated example. The vapour generating unit 12 is disposed in the interior 30 of the cup 26, i.e., the inductively heatable susceptor 22 and the liquid transfer element 24 are disposed in the interior 30 of the cup 26. In the illustrated example, the radially outer circumferential surface 23 of the inductively heatable susceptor 22 is spaced apart from the interior surface 25 of the cup 26. Accordingly, the inductively heatable susceptor 22 does not contact the cup 26. This provides a gap in the interior 30 of the cup 26 that defines an airflow path 29 between the radially outer circumferential surface 23 of the inductively heatable susceptor 22 and the interior surface 25 of the cup 26 to facilitate airflow over the inductively heatable susceptor 22. The cup 26 may comprise a heat resistant material. The heat resistant material may comprise poly ether ether ketone, ceramic or glass.

The cup 26 is configured to ensure airflow is directed into a vaporisation chamber 38 defined by the liquid transfer element 24, further improving the efficiency of vapour generation. In particular, the base 27 of the cup 26 prevents linear airflow away from the vaporisation chamber 38. The cup 26 also prevents undesirable vapour leakage.

In the illustrated example, where the vapour generating device 100 comprises the induction coil 51, the induction coil 51 fully surrounds the cup 26 when the cartridge 10 is connected to the vapour generating device 100. In examples where the induction coil 51 is an integral part of, and belongs to, the cartridge 10, the induction coil 51 fully surrounds the cup 26.

The cartridge 16 further comprises at least two air inlets 32 through which air is flowable in use from the surrounding environment through a corresponding number of aligned airflow channels 34 into the interior 30 of the cup 26 to flow over the inductively heatable susceptor 22. In the illustrated example, the cartridge 10 comprises six air inlets 32.

In the illustrated example, the liquid transfer element 24 is toroidal and comprises a hollow core 36 and a base 40. The hollow core 36 of the liquid transfer element 24 defines the vaporisation chamber 38.

The vaporisation chamber 38 may be substantially cylindrical and centrally positioned. The vaporisation chamber 38 is aligned with, and fluidly connected to, the vapour outlet channel 52. The vaporisation chamber 38 provides a route which allows vapour generated by heating the vapour generating liquid to be transferred into the vapour outlet channel 52 where it cools and condenses to form an aerosol that can be inhaled by a user via the mouthpiece 54. The vapour generated in the vaporisation chamber 38 may cool and condense to form an aerosol as it flows along the vapour outlet channel 52, from the vaporisation chamber 38 towards an end of the vapour outlet channel 52. Efficient vapour generation is thereby assured. In particular, a continuous process is achieved in which vapour generating liquid from the liquid store 16 is continuously absorbed by the liquid transfer element 24 and heated by the inductively heatable susceptor 22 to generate a vapour in the vaporisation chamber 38. The vaporisation of the vapour generating liquid is facilitated by the addition of air from the surrounding environment through the at least two air inlets 32 and the aligned airflow channels 34. The flow of air and/or vapour may be aided by negative pressure created by a user drawing air through the mouthpiece 54.

Air flowing through the at least two air inlets 32 and corresponding number of aligned airflow channels 34 into the interior 30 of the cup 26 is distributed uniformly over the surface of the inductively heatable susceptor 22. This ensures vapour is efficiently generated. Accordingly, a high volume of vapour is generated. Airflow may be distributed uniformly over the entire surface of the inductively heatable susceptor 22.

The base 40 of the liquid transfer element 24 comprises at least one indentation 42 which engages with the cup 26. The at least one indentation 42 is configured such that an airflow path is defined for allowing air to flow from the interior 30 of the cup 26 into the vaporisation chamber 38.

The at least one indentation may have a height of from 0.1 mm to 5 mm, or preferably may have a height of from 0.5 mm to 2 mm. The at least one indentation may have a width of from 0.5 mm to 10 mm, or preferably may have a width of from 1 mm to 3 mm.

In the illustrated example, the liquid transfer element 24 comprises a plurality of indentations 42. Accordingly, the base 40 of the liquid transfer element 24 is castellated. The base 40 of the liquid transfer element 24 may comprise from 2 to 20 indentations 42, or preferably may comprise from 8 to 12 indentations.

In the illustrated example, the airflow channels 34 have a generally radial configuration around the interior 30 of the cup 26. The airflow channels 34 are uniformly spaced around the interior 30 of the cup 26. This further improves the distribution of airflow uniformly over the surface of the inductively heatable susceptor 22 in use, which in turn further improves the efficiency of vapour generation.

In the illustrated example, each of the airflow channels 34 extends at an angle through a body 44 of the cup 26 into the interior 30 of the cup 26. In such examples, in use air flows through each airflow channel 34 into the interior 30 of the cup 26 at an angle. The angled arrangement of the airflow channels 34 causes air entering the interior 30 of the cup 26 in use to create a vortex, i.e., a spinning or rotating stream, which flows radially over the surface of the inductively heatable susceptor 22. Accordingly, in use air circulates around the inductively heatable susceptor 22. This further improves the distribution of airflow uniformly over the surface of the inductively heatable susceptor 22, which in turn further improves the efficiency of vapour generation. Furthermore, the possibility of undesirable condensation of vapours is reduced because the air vortex created limits the formation of areas of non-moving air. Furthermore, circulation of air causes heat to be transferred away from an outer surface of the cartridge 10. Circulation of air over the inductively heatable susceptor 22 in use also warms the air before it contacts vapours generated, improving efficiency.

In some examples, the airflow channels 34 extend into the interior 30 of the cup 26 adjacent the liquid store 16. In such examples, in use air flowing into the interior 30 of the cup 26 limits thermal energy transfer from the vapour generating unit 12, i.e., from the inductively heatable susceptor 22 and/or the liquid transfer element 24, to the liquid store 16. This arrangement interrupts the undesirable thermal bridge otherwise created in use between the inductively heatable susceptor 22 and/or liquid transfer element 24 of the vapour generating unit 12 and the liquid store 16 by causing cool air to be directed to this area.

In operation of the vapour generating system 110, vapour generating liquid is conveyed from the liquid store 16 to the liquid transfer element 24. The vapour generating liquid is held and transferred by the liquid transfer element 24 (by capillary action) and is heated by the heat transferred to the liquid transfer element 24 from the inductively heatable susceptor 22. As noted above, when the cartridge 10 is used with a vapour generating device 100 including an induction coil 51, the inductively heatable susceptor 22 is inductively heated by the electromagnetic field generated by the induction coil 51. The heat from the inductively heatable susceptor 22 is transferred to vapour generating liquid held and transferred by the liquid transfer element 24, resulting in the generation of a vapour. The vapour escapes from the liquid transfer element 24 into the vaporisation chamber 38, and then flows from the vaporisation chamber 38 along the vapour outlet channel 52 where it cools and condenses to form an aerosol that is inhaled by a user through the mouthpiece 54. As illustrated in Figure 2b, which shows airflow (indicated by arrows), the vaporisation of the vapour generating liquid is facilitated by the addition of air flowing from the surrounding environment through the at least two air inlets 32 and corresponding number of aligned airflow channels 34 into the interior 30 of the cup 26. The at least two air inlets 32 are arranged such that airflow is distributed uniformly over the surface of the inductively heatable susceptor 22. Air flows from the interior 30 of the cup 26 into the vaporisation chamber 38 via the airflow path defined by the at least one indentation 42 comprised in the base 40 of the liquid transfer element 24. Air then flows from the vaporisation chamber 38 along the vapour outlet channel 52 to the mouthpiece 54. Vapour generated is entrained in the air as it flows from the interior 30 of the cup 26 into the vaporisation chamber 38 and along the vapour outlet channel 52 to the mouthpiece 54.

The flow of air and/or vapour through the cartridge 10, i.e., through the vaporisation chamber 38, along the vapour outlet channel 52, and out of the mouthpiece 54, is aided by negative pressure created by a user drawing air through the mouthpiece 54.

The figures also illustrate a method of manufacturing a cartridge 10 and a device 100 according to examples of the disclosure. The figures also illustrate a method of providing a system 110 according to examples of the disclosure.

Although exemplary embodiments have been described in the preceding paragraphs, it should be understood that various modifications may be made to those embodiments without departing from the scope of the appended claims. Thus, the breadth and scope of the claims should not be limited to the above-described exemplary embodiments.

Any combination of the above-described features in all possible variations thereof is encompassed by the present disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.

Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like, are to be construed in an inclusive as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.

Claims

1. A cartridge (10) for a vapour generating device (100), wherein the cartridge (10) comprises: a liquid store (16) for containing a vapour generating liquid; a vapour generating unit (12), the vapour generating unit (12) comprising: a vaporisation device (18) including a heating element (20) comprising an inductively heatable susceptor (22); and a liquid transfer element (24) positioned outside an inner volume of the liquid store (16) and arranged to hold and transfer vapour generating liquid from the liquid store (16) to the vaporisation device (18) by capillary action, wherein the inductively heatable susceptor (22) extends around a radially outer circumferential surface (48) of the liquid transfer element (24) and includes a radially inner circumferential surface (46) that contacts the radially outer circumferential surface (48) of the liquid transfer element (24) to heat and vaporise the vapour generating liquid held and transferred to the vaporisation device (18) by the liquid transfer element (24); the cartridge (10) further comprising: a cup (26) defining an airflow guide (28), wherein the vapour generating unit (12) is disposed in the interior (30) of the cup (26) and a radially outer circumferential surface (23) of the inductively heatable susceptor (22) is spaced apart from an interior surface (25) of the cup (26) to define an airflow path (29) therebetween; and at least two air inlets (32) through which air is flowable in use from the surrounding environment through a corresponding number of aligned airflow channels (34) into the interior (30) of the cup (26) along the airflow path (29) to flow over the radially outer circumferential surface (23) of the inductively heatable susceptor (22).

2. A cartridge (10) according to claim 1, wherein the cartridge (10) comprises at least three air inlets (32).

3. A cartridge (10) according to claim 1 or claim 2, wherein the liquid transfer element (24) comprises a hollow core (36) and a base (40), wherein the hollow core (36) defines a vaporisation chamber (38), wherein the base (40) comprises at least one indentation (42) which engages with the cup (26), wherein the at least one indentation (42) is configured such that an airflow path is defined for allowing air to flow from the interior (30) of the cup (26) into the vaporisation chamber (38).

4. A cartridge (10) according to claim 3, wherein the base (40) of the liquid transfer element (24) comprises a plurality of indentations (42).

5. A cartridge (10) according to any of the preceding claims, wherein the airflow channels (34) have a generally radial configuration around the interior (30) of the cup (26).

6. A cartridge (10) according to any of the preceding claims, wherein the airflow channels (34) are uniformly spaced around the interior (30) of the cup (26).

7. A cartridge (10) according any of the preceding claims, wherein each of the airflow channels (34) extends at an angle through a body (44) of the cup (26) into the interior (30) of the cup (26) such that in use air flows through each airflow channel (34) into the interior (30) of the cup (26) at an angle.

8. A cartridge (10) according to any of the preceding claims, wherein the airflow channels (34) extend into the interior (30) of the cup (26) adjacent the liquid store (16) such that in use air flowing into the interior (30) of the cup (26) limits thermal energy transfer from the vapour generating unit (12) to the liquid store (16).

9. A cartridge (10) according to any of the preceding claims, wherein the liquid transfer element (24) comprises a porous ceramic.

10. A cartridge (10) according to any of the preceding claims, wherein the inductively heatable susceptor (22) is substantially cylindrical, oval or conical.

11. A cartridge (10) according to any of the preceding claims, wherein the inductively heatable susceptor (22) is positioned beneath the liquid store (16).

12. A cartridge (10) according to any of the preceding claims, wherein a vapour outlet channel (52) is fluidly connected to a mouthpiece (54), wherein the mouthpiece (54) comprises a thermally insulating material.

13. A vapour generating system (110) comprising a vapour generating device (100) and a cartridge (10) according to any of the preceding claims.