CARTRIDGE FOR USE WITH AN AEROSOL PROVISION SYSTEM

A cartridge for an aerosol provision system. The cartridge includes an air channel extending from an air inlet to an outlet via an aerosol generation region. The cartridge also includes a heating element for heating liquid from a reservoir to generate aerosol and an aerosol outlet tube. The aerosol outlet tube has a first end and a second end. The first end is proximate to the aerosol generation region and second end is configured to fit inside an air channel seal. The aerosol outlet tube tapers inwardly from the first end to the second end such that a cross-sectional area of the second end is less than a cross-sectional area of the first end. The cartridge is configured such that air passes from the air inlet, into the aerosol generating region, through the aerosol outlet tube, past the air channel seal and then out from the outlet.

TECHNICAL FIELD

The present invention relates to cartridges for use with an aerosol provision system and a system comprising the cartridge.

BACKGROUND

Electronic aerosol provision systems such as electronic cigarettes (e-cigarettes) generally contain an aerosol precursor material, such as a reservoir of a source liquid containing a formulation, typically including nicotine, or a solid material such a tobacco-based product, from which an aerosol is generated for inhalation by a user, for example through heat vaporization. Thus, an aerosol provision system will typically comprise a heating element, e.g. a heating element, arranged to vaporize a portion of precursor material to generate an aerosol in an aerosol generation region of an air channel through the aerosol provision system. As a user inhales on the device and electrical power is supplied to the heating element, air is drawn into the device through one or more inlet holes and along the air channel to the aerosol generation region, where the air mixes with the vaporized precursor material and forms a condensation aerosol. The air drawn through the aerosol generation region continues along the air channel to a mouthpiece opening, carrying some of the aerosol with it, and out through the mouthpiece opening for inhalation by the user.

It is common for aerosol provision systems to comprise a modular assembly, often having two main functional parts, namely an aerosol provision device and disposable/replaceable cartridge part. Typically, the cartridge part will comprise the consumable aerosol precursor material and the heating element (atomizer), while the aerosol provision device part will comprise longer-life items, such as a rechargeable battery, device control circuitry, activation sensors and user interface features. The aerosol provision device may also be referred to as a reusable part or battery section and the replaceable cartridge may also be referred to as a disposable part or cartomizer.

The aerosol provision device and cartridge are mechanically coupled together at an interface for use, for example using a screw thread, bayonet, latched or friction fit fixing. When the aerosol precursor material in a cartridge has been exhausted, or the user wishes to switch to a different cartridge having a different aerosol precursor material, the cartridge may be removed from the aerosol provision device and a replacement cartridge may be attached to the device in its place.

A potential drawback for cartridges containing liquid aerosol precursor (e-liquid) is the risk of leakage. An e-cigarette cartridge will typically have a mechanism, e.g. a capillary wick, for drawing liquid from a liquid reservoir to a heating element located in an air path/channel connecting from an air inlet to an aerosol outlet for the cartridge. Because there is a fluid transport path from the liquid reservoir into the open-air channel through the cartridge, there is a corresponding risk of liquid leaking from the cartridge. Leakage is undesirable both from the perspective of the end user naturally not wanting to get the e-liquid on their hands or other items, and also from a reliability perspective, since leakage from an end of the cartridge connected to the aerosol provision device may damage the aerosol provision device, for example due to corrosion. Some approaches to reduce the risk of leakage may involve restricting the flow of liquid to the heating element, for example by tightly clamping a wick where it enters the air channel, but this can in some scenarios lead to a risk of insufficient liquid being supplied to the heating element (dry-out), which can give rise to overheating and undesirable flavors.

Various approaches are described herein which seek to help address or mitigate some of the issues discussed above.

SUMMARY

The disclosure is defined in the appended claims.

In accordance with some embodiments described herein, there is provided a cartridge for an aerosol provision system comprising the cartridge and an aerosol provision device, the cartridge comprising an air channel extending from an air inlet for the cartridge to an outlet via an aerosol generation region, a heating element for heating liquid from a reservoir to generate aerosol in the aerosol generation region, an aerosol outlet tube having a first end and a second end, the first end proximate to the aerosol generation region and second end configured to fit inside an air channel seal, wherein the aerosol outlet tube tapers inwardly from the first end to the second end such that a cross-sectional area of the second end is less than a cross-sectional area of the first end and wherein the cartridge is configured such that air passing through the air channel is configured to pass from the air inlet, into the aerosol generating region, through the aerosol outlet tube, past the air channel seal and then out from the outlet.

The aerosol outlet tube may taper inwardly from the first end to a position between the first end and the second end according to a first profile, and the aerosol outlet tube may taper inwardly from the position to the second end according to a second profile, wherein the first profile and the second profile are different.

The first profile may correspond to a first taper angle and the second profile may correspond to a second taper angle.

The first taper angle may be greater than the second taper angle.

The position may be less than 50% of a distance along the aerosol outlet tube from the first end to the second end; for example, the position may be less than 25% of the distance along the aerosol outlet tube from the first end to the second end.

The portion of the air channel from the air channel seal to the outlet may have a substantially constant cross-sectional area.

The cross-sectional area of the portion of the air channel from the air channel seal to the outlet may be less than the cross-sectional area of the second end of the aerosol outlet tube.

The aerosol outlet tube may be made of a plastics material, for example polypropylene.

The air channel seal may be made of silicone.

The cartridge may further comprise a housing part having a mouthpiece end and an interface end, wherein the mouthpiece end includes the outlet of the cartridge and the interface end includes an interface for coupling the cartridge to the aerosol provision device, wherein the housing part contains the aerosol outlet tube, the air channel seal and the reservoir within the housing part, the reservoir containing liquid for aerosolization, wherein the reservoir at least partially surrounds the aerosol outlet tube and the air channel seal.

In accordance with some embodiments described herein, there is provided an aerosol provision system, the system comprising an air channel extending from an air inlet for the system to an outlet via an aerosol generation region, a heating element for heating liquid from a reservoir to generate aerosol in the aerosol generation region, an aerosol outlet tube having a first end and a second end, the first end proximate to the aerosol generation region and second end configured to fit inside an air channel seal, wherein the aerosol outlet tube tapers inwardly from the first end to the second end such that a cross-sectional area of the second end is less than a cross-sectional area of the first end, and wherein the system is configured such that air passing through the air channel is configured to pass from the air inlet, into the aerosol generating region, through the aerosol outlet tube, past the air channel seal and then out from the outlet.

In accordance with some embodiments described herein, there is provided a method of generating aerosol from a cartridge for an aerosol provision system, wherein the cartridge comprises an air channel extending from an air inlet for the cartridge to an outlet via an aerosol generation region, a heating element for heating liquid from a reservoir to generate aerosol in the aerosol generation region, an aerosol outlet tube having a first end and a second end, the first end proximate to the aerosol generation region and second end configured to fit inside an air channel seal, wherein the aerosol outlet tube tapers inwardly from the first end to the second end such that a cross-sectional area of the second end is less than a cross-sectional area of the first end, wherein the method comprises passing air through the air channel from the air inlet, into the aerosol generating region, through the aerosol outlet tube, past the air channel seal and then out from the outlet.

Thus, it will be appreciated that the combination of air channel, heating element, aerosol outlet tube and air channel seal described herein need not be limited to being located in an cartridge for use with an aerosol provision system, but may for part of an aerosol provision system or component thereof, such as an aerosol delivery device.

The cartridge can be used with an aerosol provision device so as to form an aerosol provision system. The aerosol provision device typically comprises a power source and a controller. In some instances, the aerosol provision device will contain the aerosol-generating component. During operation of the aerosol provision device, the controller will determine that a user has initiated a request for the generation of an aerosol. This could be done via a button on the device, which sends a signal to the controller that the aerosol generator should be powered. Alternatively, a sensor located in or proximal to the airflow pathway could detect airflow through the airflow pathway and convey this detection to the controller. A sensor may also be present in addition to the presence of a button, as the sensor may be used to determine certain usage characteristics, such as airflow, timing of aerosol generation etc.

These aspects and other aspects will be apparent from the following detailed description. In this regard, particular sections of the description are not to be read in isolation from other sections.

DETAILED DESCRIPTION OF THE DRAWINGS

The present disclosure relates to aerosol provision systems, which may also be referred to as aerosol provision systems, such as e-cigarettes. Throughout the following description the term “e-cigarette” or “electronic cigarette” may sometimes be used, but it will be appreciated this term may be used interchangeably with aerosol provision system and electronic aerosol provision system.

As noted above, aerosol provision systems (e-cigarettes) often comprise a modular assembly including both a reusable part (aerosol provision device) and a replaceable (disposable) cartridge part. Devices conforming to this type of two-part modular configuration may generally be referred to as two-part devices. It is also common for electronic cigarettes to have a generally elongate shape. For the sake of providing a concrete example, certain embodiments of the disclosure described herein comprise this kind of generally elongate two-part device employing disposable cartridges. However, it will be appreciated the underlying principles described herein may equally be adopted for other electronic cigarette configurations, for example modular devices comprising more than two parts, as devices conforming to other overall shapes, for example based on so-called box-mod high performance devices that typically have a more boxy shape.

As described above, the present disclosure relates to (but it not limited to) cartridges for use with aerosol provision systems, such as e-cigarettes and electronic cigarettes.

FIG.1is a schematic perspective view of an example aerosol provision system (e-cigarette)1in accordance with certain embodiments of the disclosure. Terms concerning the relative location of various aspects of the electronic cigarette (e.g. terms such as upper, lower, above, below, top, bottom etc.) are used herein with reference to the orientation of the electronic cigarette as shown inFIG.1(unless the context indicates otherwise). However, it will be appreciated this is purely for ease of explanation and is not intended to indicate there is any required orientation for the electronic cigarette in use.

The e-cigarette1comprises two main components, namely a cartridge2and an aerosol provision device4. The aerosol provision device4and the cartridge2are shown separated inFIG.1, but are coupled together when in use.

The cartridge2and aerosol provision device4are coupled by establishing a mechanical and electrical connection between them. The specific manner in which the mechanical and electrical connection is established is not of primary significance to the principles described herein and may be established in accordance with conventional techniques, for example based around a screw thread, bayonet, latched or friction-fit mechanical fixing with appropriately arranged electrical contacts/electrodes for establishing the electrical connection between the two parts as appropriate. For example, electronic cigarette1represented inFIG.1, the cartridge comprises a mouthpiece end52and an interface end54and is coupled to the aerosol provision device4by inserting an interface end portion6at the interface end of the cartridge into a corresponding receptacle8/receiving section of the aerosol provision device4. The interface end portion6of the cartridge is a close fit to be receptacle8and includes protrusions56, which engage with corresponding detents in the interior surface of a receptacle wall12defining the receptacle8to provide a releasable mechanical engagement between the cartridge2and the aerosol provision device4. An electrical connection is established between the aerosol provision device4and the cartridge via a pair of electrical contacts on the bottom of the cartridge (not shown inFIG.1) and corresponding sprung contact pins in the base of the receptacle8(not shown inFIG.1). As noted above, the specific manner in which the electrical connection is established is not significant to the principles described herein, and indeed some implementations might not have an electrical connection between the cartridge and an aerosol provision device at all, for example because the transfer of electrical power from the reusable part to the cartridge may be wireless (e.g. based on electromagnetic induction techniques).

The electronic cigarette1has a generally elongate shape extending along a longitudinal axis L. When the cartridge is coupled to the aerosol provision device, the overall length of the electronic cigarette in this example (along the longitudinal axis) is around 12.5 cm. The overall length of the aerosol provision device4is around 9 cm and the overall length of the cartridge2is around 5 cm (i.e. there is around 1.5 cm of overlap between the interface end portion6of the cartridge and the receptacle8of the aerosol provision device4when they are coupled together). The electronic cigarette1has a cross-section which is generally oval and which is largest around the middle of the electronic cigarette1and tapers in a curved manner towards the ends. The cross-section around the middle of the electronic cigarette has a width of around 2.5 cm and a thickness of around 1.7 cm. The end of the cartridge2has a width of around 2 cm and a thickness of around 0.6 mm, whereas the other end of the electronic cigarette1has a width of around 2 cm and a thickness of around 1.2 cm. The outer housing of the electronic cigarette1is in this example is formed from a plastics material. It will be appreciated the specific size and shape of the electronic cigarette and the material from which it is made is not of primary significance to the principles described herein and may be different in different implementations. That is to say, the principles described herein may equally be adopted for electronic cigarettes having different sizes, shapes and/or materials.

The aerosol provision device4may in accordance with certain embodiments of the disclosure be broadly conventional in terms of its functionality and general construction techniques. In the example ofFIG.1, the aerosol provision device4comprises a plastic outer housing10including the receptacle wall12that defines the receptacle8for receiving the end of the cartridge as noted above. The outer housing10of the aerosol provision device4in this example has a generally oval cross section conforming to the shape and size of the cartridge2at their interface to provide a smooth transition between the two parts. The receptacle8and the end portion6of the cartridge2are symmetric when rotated through 180° so the cartridge can be inserted into the aerosol provision device in two different orientations. The receptacle wall12includes two aerosol provision device air inlet openings14(i.e. holes in the wall). These openings14are positioned to align with an air inlet50for the cartridge when the cartridge is coupled to the aerosol provision device. A different one of the openings14aligns with the air inlet50of the cartridge in the different orientations. It will be appreciated some implementations may not have any degree of rotational symmetry such that the cartridge is couplable to the aerosol provision device in only one orientation while other implementations may have a higher degree of rotational symmetry such that the cartridge is couplable to the aerosol provision device in more orientations.

The aerosol provision device further comprises a battery16for providing operating power for the electronic cigarette, control circuitry18for controlling and monitoring the operation of the electronic cigarette, a user input button20, an indicator light22, and a charging port24.

The battery16in this example is rechargeable and may be of a conventional type, for example of the kind normally used in electronic cigarettes and other applications requiring provision of relatively high currents over relatively short periods. The battery16may be recharged through the charging port24, which may, for example, comprise a USB connector.

The input button20in this example is a conventional mechanical button, for example comprising a sprung mounted component, which may be pressed by a user to establish an electrical contact in underlying circuitry. In this regard, the input button may be considered an input device for detecting user input, e.g. to trigger aerosol generation, and the specific manner in which the button is implemented is not significant. For example, other forms of mechanical button or touch-sensitive button (e.g. based on capacitive or optical sensing techniques) may be used in other implementations, or there may be no button and the device may rely on a puff detector for triggering aerosol generation.

The indicator light22is provided to give a user with a visual indication of various characteristics associated with the electronic cigarette, for example, an indication of an operating state (e.g. on/off/standby), and other characteristics, such as battery life or fault conditions. Different characteristics may, for example, be indicated through different colors and/or different flash sequences in accordance with generally conventional techniques.

The control circuitry18is suitably configured/programmed to control the operation of the electronic cigarette to provide conventional operating functions in line with the established techniques for controlling electronic cigarettes. The control circuitry (processor circuitry)18may be considered to logically comprise various sub-units/circuitry elements associated with different aspects of the electronic cigarette's operation. For example, depending on the functionality provided in different implementations, the control circuitry18may comprises power supply control circuitry for controlling the supply of power from the battery to the cartridge in response to user input, user programming circuitry for establishing configuration settings (e.g. user-defined power settings) in response to user input, as well as other functional units/circuitry associated functionality in accordance with the principles described herein and conventional operating aspects of electronic cigarettes, such as indicator light display driving circuitry and user input detection circuitry. It will be appreciated the functionality of the control circuitry18can be provided in various different ways, for example using one or more suitably programmed programmable computer(s) and/or one or more suitably configured application-specific integrated circuit(s)/circuitry/chip(s)/chipset(s) configured to provide the desired functionality.

FIG.2is an exploded schematic perspective view of the cartridge2(exploded along the longitudinal axis L). The cartridge2comprises a housing part32, an air channel seal34, a dividing wall element36, an aerosol outlet tube38, a heating element40, a liquid transport element42, a plug44, and an end cap48with contact electrodes46.

FIG.3is a schematic cut-away view of an alternative example of a cartridge2for an aerosol provision system1, where the same reference signs have been used for like elements between the cartridge2illustrated inFIG.2and the cartridge2illustrated inFIG.3. The cartridge2illustrated inFIG.3also comprises a housing part32, an air channel seal34, a heating element40, a liquid transport element42, a plug44, and an end cap48with contact electrodes46. The cartridge2illustrated inFIG.3, however, has an aerosol outlet tube38, which also acts as a dividing wall. In other words, the aerosol outlet tube38inFIG.3is a single component integrating the design and functionality of both the dividing wall element36and the aerosol outlet tube38illustrated inFIG.2.

In both the examples inFIG.2andFIG.3, the housing part32comprises a housing outer wall64and a housing inner tube62which are formed from a single molding of polypropylene. The housing outer wall64defines the external appearance of the cartridge2and the housing inner tube62defines a part an air channel through the cartridge2. The housing part is open at the interface end54of the cartridge and closed at the mouthpiece end52of the cartridge except for a mouthpiece opening/aerosol outlet60in fluid communication with the housing inner tube62. The housing part32includes an opening in a sidewall, which provides the air inlet50for the cartridge. The air inlet50in both examples has an area of around 2 mm2. The housing part32includes the protrusions56discussed above which engage with corresponding detents in the interior surface of the receptacle wall12defining the receptacle8to provide a releasable mechanical engagement between the cartridge and the control unit. The inner surface of the outer wall64of the housing part includes further protrusions66which act to provide an abutment stop for locating the plug44and the end cap48along the longitudinal axis L when the cartridge is assembled.

The air channel seal34in both examples is a silicone molding generally in the form of a tube having a through hole80. The outer wall of the air channel seal34includes circumferential ridges84and an upper collar82. The inner wall of the air channel seal34also includes circumferential ridges86. When the cartridge is assembled the air channel seal34is mounted to the housing inner tube62with an end of the housing inner tube62extending partly into the through hole80of the air channel seal34. The through hole80in the air channel seal has a diameter of around 5.8 mm in its relaxed state whereas the end of the housing inner tube62has a diameter of around 6.2 mm so that a seal is formed when the air channel seal34is stretched to accommodate the housing inner tube62. This seal is facilitated by the86ridges on the inner surface of the air channel seal34.

In the example inFIG.2, the outlet tube38comprises a tubular section of ANSI304stainless steel with an internal diameter of around 8.6 mm and a wall thickness of around 0.2 mm, whilst the outlet tube38the example inFIG.3is made of polypropylene. In both examples, the bottom end of the outlet tube38includes a pair of diametrically opposing slots88with an end of each slot having a semi-circular recess90. When the cartridge2is assembled, the outlet tube38mounts to the outer surface of the air channel seal34. The outer diameter of the air channel seal34is around 9.0 mm in its relaxed state so that a seal is formed when the air channel seal34is compressed to fit inside the outlet tube38. This seal is facilitated by the ridges84on the outer surface of the air channel seal34. The collar82on the air channel seal34provides a stop for the outlet tube38.

The liquid transport element42comprises a capillary wick and the heating element40comprises a resistance wire heater wound around the capillary wick. For ease of illustration, the liquid transport element42and the heating element40have been omitted fromFIG.3. In addition to the portion of the resistance wire wound around the capillary wick, the heating element comprises electrical leads41which pass through holes in the plug44to contact electrodes46mounted to the end cap54to allow power to be supplied to the heating element via the electrical interface the established when the cartridge is connected to a control unit. The heating element leads41may comprise the same material as the resistance wire wound around the capillary wick, or may comprise a different material (e.g. lower-resistance material) connected to the resistance wire wound around the capillary wick. In both examples, the heater coil40comprises a nickel iron alloy wire and the wick42comprises a glass fiber bundle. The heating element and liquid transport element may be provided in accordance with any conventional techniques and is may comprise different forms and/or different materials. For example, in some implementations, the wick may comprise fibrous or solid a ceramic material and the heater may comprise a different alloy. In other examples, the heater and wick may be combined, for example in the form of a porous and a resistive material. More generally, it will be appreciated the specific nature liquid transport element and heating element is not of primary significance to the principles described herein.

When the cartridge is assembled, the wick42is received in the semi-circular recesses90of the outlet tube38so that a central portion of the wick about which the heating coil is would is inside the outlet tube while end portions of the wick are outside the outlet tube38.

The plug44in the examples illustrated inFIG.2andFIG.3comprises a single molding of silicone, which may be resilient. The plug comprises a base part100with a wall102extending upwardly therefrom (i.e. towards the mouthpiece end of the cartridge).

The outer portion of the wall102of the plug44conforms to an inner surface of the housing part32so that when the cartridge is assembled the plug in44forms a seal with the housing part32. The inner portion of the wall104of the plug44conforms to an inner surface of the outlet tube38so that when the cartridge is assembled the plug44also forms a seal with the outlet tube38.

The end cap48comprises a polypropylene molding with a pair of gold-plated copper electrode posts46mounted therein. The ends of the electrode posts46on the bottom side of the end cap48are close to flush with the interface end54of the cartridge provided by the end cap48. These are the parts of the electrodes to which correspondingly aligned sprung contacts in the control unit connect when the cartridge is assembled and connected to the control unit. The ends of the electrode posts on the inside of the cartridge extend away from the end cap48and into the holes in the plug44through which the contact leads41pass. The electrode posts46are slightly oversized relative to the holes and include a chamfer at their upper ends to facilitate insertion into the holes in the plug44where they are maintained in pressed contact with the contact leads for the heating element40by virtue of the plug44.

In the example illustrated inFIG.2, the dividing wall element36comprises a single molding of polypropylene and includes a dividing wall130. The dividing wall element36has a central opening through which the outlet tube38passes (i.e. the dividing wall130is arranged around the outlet tube38). When the cartridge is assembled, the upper surface of the outer wall of the plug44engages with the lower surface of the dividing wall130, and the upper surface of the dividing wall130in turn engages with the projections66on the inner surface of the outer wall64of the housing part32. Thus, the dividing wall130prevents the plug from being pushed too far into the housing part32. In other words, the dividing wall130is fixedly located along the longitudinal axis of the cartridge by the protrusions66in the housing part and so provides the plug with a fixed surface to push against. The dividing wall element36also comprises a first pair of opposing projections/tongues134, which extend from the dividing wall130in the direction towards the interface end of the cartridge. The pair of opposing projections134engage with corresponding recesses on an inner surface of the outer wall of the plug44. The projections134from the dividing wall130further provide a pair of cradle sections136configured to engage with corresponding ones of the cradle sections in the plug44when the cartridge2is assembled to further define the opening through which the liquid transport element42passes.

In the example illustrated inFIG.3, the dividing wall130is incorporated into the outlet tube38. In other words, the outlet tube38has an outwardly extending flange130, which acts as a dividing wall, thereby removing the need for a separate dividing wall element36since the functionality of the dividing wall element is incorporated into the outlet tube38. In the same way as described above, when the cartridge2is assembled, the upper surface of the outer wall of the plug44engages with the lower surface of the dividing wall130, and the upper surface of the dividing wall130in turn engages with the projections66on the inner surface of the outer wall64of the housing part32.

In both the examples illustrated inFIGS.2and3, when the cartridge2is assembled, a reservoir63for liquid is formed by the space outside the inner tube62of the housing32and inside the outer wall64of the housing32. This may be filled during manufacture, for example through a filling hole, which is then sealed, or by other means. The specific nature of the liquid, for example in terms of its composition, is not of primary significance to the principles described herein, and in general any conventional liquid of the type normally used in electronic cigarettes may be used. The reservoir63is closed at the interface end of the cartridge by the plug44. The reservoir includes a first region above the dividing wall130and a second region below the dividing wall130within the space formed between the aerosol outlet tube38and the plug44. The liquid transport element (capillary wick)42passes through openings in the wall of the outlet tube38provided by the semi-circular recesses90. Thus, the ends of the liquid transport element42extend into the second region of the reservoir63from which they draw liquid to the heating element40for subsequent vaporization.

In normal use, the cartridge2is coupled to the control unit4and the control unit activated to supply power to the cartridge via the contact electrodes46in the end cap48. Power then passes through the connection leads41to the heating element40. The heating element is thus electrically heated and so vaporizes a portion of the liquid from the liquid transport element in the vicinity of the heating element40. This generates aerosol in an aerosol generation region, which includes the heating element. Liquid that is vaporized from the liquid transport element is replaced by more liquid drawn from the reservoir by capillary action. While the heating element40is activated, a user inhales on the mouthpiece end52of the cartridge2. This causes air to be drawn through whichever control unit air inlet14aligns with the air inlet50of the cartridge (which will depend on the orientation in which the cartridge was inserted into the control unit receptacle8). Air then enters the cartridge2through the air inlet50before entering the aerosol generation region surrounding the heating element40. The incoming air mixes with aerosol generated from the heating element40to form a condensation aerosol, which is then drawn along the outlet tube38and the housing part inner62before exiting through the mouthpiece outlet/aerosol outlet60for user inhalation.

FIG.4is a schematic cut-away view of a modified example of a cartridge2for an aerosol provision system1, where the same reference signs have been used for like elements between the cartridge2illustrated inFIGS.2and3and the cartridge2illustrated inFIG.4. As per the cartridge illustrated inFIG.3, the cartridge2illustrated inFIG.4comprises a housing part32, an air channel seal34, a heating element40, a liquid transport element42, a plug44, an end cap48with contact electrodes46, and an aerosol outlet tube38which also acts as a dividing wall. In other words, the aerosol outlet tube38inFIG.4also has an integrated dividing wall130.

In the example illustrated inFIG.4, an air channel is defined as extending from the air inlet50for the cartridge2to the outlet60. The air channel extends through the aerosol generation region43in which the heating element40is located. As described above, the heating element40heats liquid from the reservoir63to generate aerosol in the aerosol generation region43. The cartridge2is configured such that air passing through the air channel passes from the air inlet50, into the aerosol generating region43, through the aerosol outlet tube38, past the air channel seal34and then out from the outlet60.

The aerosol outlet tube38has a first end38aproximate to the aerosol generation region43and a second end38bconfigured to fit inside the air channel seal34. The air channel seal34illustrated inFIG.4has an inner flange81and an outer flange83. The outer flange83is located outside the inner flange81, in other words a larger radial distance away from the longitudinal axis L. This forms a slot between the inner flange81and the outer flange83. The slot is a size and shape to receive the second end38bof the aerosol outlet tube38. In other words, the second end38bof the aerosol outlet tube38is configured to fit inside the air channel seal34, such that when the cartridge2is assembled, a compression fit is achieved between the second end38bof the outlet tube38, the inner flange81and the outer flange83of the air channel seal34. Therefore, when the cartridge is assembled2, the inner flange81of the air channel seal34is located inside the outlet tube38(in other words closer to the longitudinal axis L), and the outlet tube38is located inside the outer flange83of the air channel seal34(in other words further from the longitudinal axis L).

The aerosol outlet tube38tapers inwardly from the first end38ato the second end38bsuch that a cross-sectional area of the second end38bis less than a cross-sectional area of the first end38a.This is shown in more detail inFIGS.5and6.

FIG.5is a schematic cut-away view of the aerosol outlet tube38of the cartridge2ofFIG.4whilstFIGS.6A and6Bare schematic plan views of the aerosol outlet tube of the cartridge ofFIG.4. As illustrated inFIG.5, the aerosol outlet tube38tapers inwardly from the first end38ato the second end38b.In other words, the walls of the aerosol outlet tube38at the second end38bof the aerosol outlet tube38are closer to the longitudinal axis L of the cartridge than the walls of the aerosol outlet tube38at the first end38aof the aerosol outlet tube38. In between the first end38aand the second end38bof the aerosol outlet tube38, the walls of the aerosol outlet tube38taper inwards according to a profile. In the example illustrated inFIGS.4and5the profile corresponds to two linear profiles, but in other examples the profile may correspond to a single linear profile, in other words a single straight line between the first end38aand the second end38bof the aerosol outlet tube38, or the profile may be curved, stepped, or any other shape which results in the cross-sectional area of the second end38bbeing less than the cross-sectional area of the first end38a.In the example illustrated inFIGS.4and5, the taper is symmetrical about the longitudinal axis L such that the cross-sections of the first end38aand the second end38bof the aerosol outlet tube38are centered on the longitudinal axis L, but this is not essential, and any tapering profile which results in the cross-sectional area of the second end38bbeing less than the cross-sectional area of the first end38amay be used.

Whilst it can be seen inFIG.5that the first end38aof the aerosol outlet tube38does not correspond to the bottom38dof the aerosol outlet tube, it will be appreciated that when the aerosol outlet tube38is assembled into the cartridge2as illustrated inFIG.4, the heating element40and the liquid transport element42pass between the semi-circular recesses90such that the heating element40and the liquid transport element42are located between the first end38aof the aerosol outlet tube38and the bottom38dof the aerosol outlet tube38. This portion of the aerosol outlet tube38between the first end38aand the bottom38dof the aerosol outlet tube38therefore corresponds to, or in other words is located inside, the aerosol generation region43of the cartridge2. The first end38aof the aerosol outlet tube38therefore corresponds to the portion of the aerosol outlet tube38proximate to the aerosol generation region43as described above. In other words, the first end38aof the aerosol outlet tube38corresponds to the portion of the aerosol outlet tube38immediately following the aerosol generation region43along the air channel in the direction of air flow from the air inlet50to the outlet60.

FIG.6Ais a plan view of the bottom of the aerosol outlet tube38, in other words in the viewing direction from the end cap48to the mouthpiece52of the assembled cartridge2along the longitudinal axis L, whilstFIG.6Bis a plan view of the top of the aerosol outlet tube38, in other words in the viewing direction from mouthpiece52to the end cap48of the assembled cartridge2along the longitudinal axis L. The shaded portion in the center ofFIG.6Acorresponds to the cross-sectional area of the first end38aof the aerosol outlet tube38whilst the shaded portion in the center ofFIG.6Bcorresponds to the cross-sectional area of the second end38bof the aerosol outlet tube38. As can be seen fromFIGS.6A and6B, due to the inward taper of the aerosol outlet tube38from the first end38ato the second end38b,the cross-sectional area of the second end38b,indicated by the shaded region inFIG.6B, is less than the cross-sectional area of the first end38a,indicated by the shaded region inFIG.6A.

As shown inFIG.5, the aerosol outlet tube38tapers inwardly from the first end38ato a position38cbetween the first end and the second end38b.The aerosol outlet tube38then tapers inwardly to the second end38bfrom the position38cbetween the first end and the second end38b.For ease of illustration and explanation, the relative positions of the first end38a,the position38cand the second end38bof the aerosol outlet tube38along the central axis L of the cartridge are indicated by solid horizontal lines inFIG.5.

The aerosol outlet tube38tapers inwardly from the first end38ato the position38cbetween the first end38aand the second end38baccording to a first profile and the aerosol outlet tube38tapers inwardly from the position38cto the second end38baccording to a second profile. The first profile and the second profile are different in the example illustrated inFIG.5. In this example, the first profile and the second profile are both linear profiles, but the angle of the wall of the aerosol outlet tube38between the first end38aand the position38crelative to the longitudinal axis L is different to the angle of the wall of the aerosol outlet tube38between the position38cand the second end38brelative to the longitudinal axis L. In other words, the first profile corresponds to a first taper angle θ and the second profile corresponds to a second taper angle φ, where a taper angle is defined as the angle of the wall relative to the longitudinal axis L of the cartridge2. As illustrated inFIG.5, the first taper angle θ is greater than the second taper angle φ such that the change in cross-sectional area of the aerosol outlet tube38between the first end38aand the position38cis greater than the change in cross-sectional area of the aerosol outlet tube38between the position38cand the second end38b.In other words, the cross-sectional area of the aerosol outlet tube38at the position38cis closer in magnitude to the cross-sectional area of the aerosol outlet tube38at the second end38cthan the first end38a.The first taper angle θ may be between 30° and 60°, for example 45°, whilst the second taper angle φ may be between 0.5° and 10°, for example 2°.

Whilst in the example illustrated inFIG.5, the first profile and the second profile are both linear profiles; in other examples, the first profile and the second profile may be other shapes. For example, the first profile may be curved, such as a parabolic or catenary curve whilst the second profile is linear, or vice versa. In other examples, both the first profile and the second profile are curved, but the shape of the curve defining the first profile and the curve of the second profile is different.

As illustrated inFIG.5, the position38cis less than 50% of a distance along the aerosol outlet tube38from the first end38aof the aerosol outlet tube to the second end38bof the aerosol outlet tube38, where the distance may be considered to be the distance between the first end38aof the aerosol outlet tube and the second end38bof the aerosol outlet tube38the along the longitudinal axis L of the cartridge2. In other words, the position38cis closer to the first end38aof the aerosol outlet tube than to the second end38bof the aerosol outlet tube38. In some examples, such as the example illustrated inFIG.5, the position38cis less than 25% of the distance along the aerosol outlet tube38from the first end38ato the second end38b.

As can be seen by comparingFIGS.3and4, the tapered profile of the aerosol outlet tube38illustrated inFIG.4increases the volume of the reservoir63in the region around the aerosol outlet tube38compared to the straight design of aerosol outlet tube38illustrated inFIG.3. The total volume of the reservoir63in the cartridge2with the tapered profile of the aerosol outlet tube38illustrated inFIG.4is 2.064 ml whilst the total volume of the reservoir63in the cartridge2with the straight profile of the aerosol outlet tube38illustrated inFIG.3is 2.039 ml. The tapered profile of the aerosol outlet tube38therefore increases the volume of the reservoir63in the cartridge2without changing the external shape or appearance of the cartridge2. An increased volume of reservoir allows more liquid to be stored in the cartridge2, which therefore allows more usage out of each cartridge2before the liquid is exhausted from the cartridge2and the cartridge2needs to be replaced. As illustrated inFIGS.6A and6B, the dividing wall130of the aerosol outlet tube38is in the form of an annular band around the air channel and comprises four fluid communication openings150located in respective quadrants of the band. The fluid communication openings150allow liquid stored in the reservoir63to flow through the dividing wall130and between the first region and the second region of the reservoir63.

Referring again toFIG.4, the housing part32has a mouthpiece end52and an interface end54. The mouthpiece end52includes the outlet60of the cartridge2and the interface end54includes an interface for coupling the cartridge2to the aerosol provision device4. The housing part32contains the aerosol outlet tube38, the air channel seal34. The reservoir63is also contained within the housing part32, and the reservoir63contains liquid for aerosolization. As can be seen inFIG.4, the reservoir63at least partially surrounds the aerosol outlet tube38and the air channel seal34. In other words, the reservoir63is located outside, or further away from the longitudinal axis L than the aerosol outlet tube38and the air channel seal34. This results in the air channel extending through the reservoir. As illustrated inFIG.4, this corresponds to the air channel passing up the center of the housing part32, with the reservoir63located outside of the central portion of the housing part32. This not essential, however, and the air channel may not be located in the center of the housing part32.

In the modified example illustrated inFIG.4, the housing inner tube62extends from the air channel seal34to outlet60, and therefore also defines a portion the air channel through the cartridge2. This portion of the air channel from the air channel seal34to the outlet60has a substantially constant cross-sectional area. This ensures a smooth or steady flow of aerosol through the air channel, reducing turbulence within the air channel and reducing the likelihood of the aerosol condensing inside the housing inner tube62.

An air gap70surrounds the housing inner tube62between the housing inner tube62and the reservoir63. This acts as a layer of insulation between the housing inner tube62and the reservoir63and further reduces the likelihood of condensates forming on the walls of the housing inner tube62inside the air channel.

As illustrated inFIG.4, the cross-sectional area of the housing inner tube62(in other words, the portion of the air channel from the air channel seal34to the outlet60) is less than the cross-sectional area of the second end38bof the aerosol outlet tube38. This acts as a restrictor in the air channel, thereby increasing the draw strength required by the user in order for the user to draw air through the air channel from the air inlet50to the air outlet60. The cross-sectional area of the air channel in the housing inner tube62is also substantially the same as the cross-sectional area of the air channel in the air channel seal34, thereby providing a smooth transition in the air channel between the air channel seal34and the housing inner tube62. The cross-sectional area of the air channel in the air channel seal34is less than the cross-sectional area of the second end38bof the aerosol outlet tube38. This not only combines with the housing inner tube62to act as a restrictor in the air channel, but also facilitates insertion of the inner flange81of the air channel seal34into the aerosol outlet tube38when the cartridge2is assembled as described above, allowing the inner flange81of the air channel seal34into be located the aerosol outlet tube38.

The aerosol outlet tube38in this modified example illustrated inFIG.4is made of a plastics material, for example polypropylene or polyethylene. This reduces the cost of manufacturing the aerosol outlet tube38in the modified example illustrated inFIG.4compared to the example illustrated inFIG.2, as the aerosol outlet tube38illustrated inFIG.2is made from a stainless steel which has a higher material cost. Additionally, the cartridge2illustrated inFIGS.3and4is made of fewer parts than the cartridge2illustrated inFIG.2, since the function of the separate dividing wall element36of the cartridge2illustrated inFIG.2in incorporated into the aerosol outlet tube38of the cartridge illustrated inFIGS.3and4, further reducing the manufacturing costs.

The air channel seal34of the modified example illustrated inFIG.4is made of silicone and is configured to rest against the housing inner tube62. In other words, the air channel seal34touches the housing inner tube62but is not fixed to the housing inner tube62. The tapered shape of the aerosol outlet tube38allows the aerosol outlet tube38and the air channel seal34to deflect downwards. In other words, the aerosol outlet tube38and the air channel seal34are able to deflect away from the housing inner tube62and towards the aerosol generation region43along the longitudinal axis L of the cartridge.

As described above, there is an air gap70surrounding the housing inner tube62between the housing inner tube62and the reservoir63. As the aerosol outlet tube38and the air channel seal34deflect away from the housing inner tube62, an opening into the air gap70is created between the air channel seal34and the housing inner tube62, allowing air to pass between the air channel and the air gap70. Typically, the air pressure in the air gap70is greater than the ambient pressure outside the cartridge2. As the user draws on the mouthpiece52, air is drawn along the air channel from the air inlet50to the air outlet60. The air is drawn through the aerosol outlet tube38and the air channel seal34, where the cross-sectional area decreases from the first end38aof the aerosol outlet tube38to the second end38bof the aerosol outlet tube38and, as described above, the cross-sectional area of the air channel through the air channel seal34and the housing inner tube62is less than the cross-sectional area of the second end38bof the aerosol outlet tube38. As a result, the speed of the aerosol through the air channel increases as the aerosol passes through the aerosol outlet tube38, the air channel seal34and the housing inner tube62. In turn, the pressure in the air channel decreases, causing the air channel seal34to be drawn towards and to rest against the housing inner tube62, closing the opening into the air gap70. When the user stops drawing on the mouthpiece52or removes their mouth from the mouthpiece end, the pressure in the air gap70is greater than the pressure in the housing inner tube62and the air channel seal34. This pressure force deflects the aerosol outlet tube38and the air channel seal34away from the housing inner tube62, creating the opening into the air gap70, which is turn, allows air to pass between the air gap70and the air channel, thereby equalizing the pressure between the air gap70and the air channel. This prevents any buildup of pressure within the cartridge2and thereby ensures that the geometry of the air channel is maintained, preventing any additional constrictions or restrictions in the air channel which may increase the draw strength required by the user and negatively impact the user experience. The ability of the aerosol outlet tube38and the air channel seal34to deflect and create the opening is facilitated by the inwards tapering of the aerosol outlet tube38from the first end38ato the second38b.The ability of the aerosol outlet tube38and the air channel seal34to deflect and create the opening is further facilitated by manufacturing the aerosol outlet tube38from a plastics material, such as polypropylene, as this provides a flexible aerosol outlet tube38that can repeatedly deflect without undergoing any permanent deformation.

Thus, there has been described a cartridge for an aerosol provision system comprising the cartridge and an aerosol provision device, wherein the cartridge an air channel extending from an air inlet for the cartridge to an outlet via an aerosol generation region, a heating element for heating liquid from a reservoir to generate aerosol in the aerosol generation region, an aerosol outlet tube having a first end and a second end, the first end proximate to the aerosol generation region and second end configured to fit inside an air channel seal, wherein the aerosol outlet tube tapers inwardly from the first end to the second end such that a cross-sectional area of the second end is less than a cross-sectional area of the first end, and wherein the cartridge is configured such that air passing through the air channel is configured to pass from the air inlet, into the aerosol generating region, through the aerosol outlet tube, past the air channel seal and then out from the outlet.

As has been described within, in some examples an aerosol provision system comprises an air channel extending from an air inlet for the system to an outlet via an aerosol generation region, a heating element for heating liquid from a reservoir to generate aerosol in the aerosol generation region, an aerosol outlet tube having a first end and a second end, the first end proximate to the aerosol generation region and second end configured to fit inside an air channel seal. The aerosol outlet tube tapers inwardly from the first end to the second end such that a cross-sectional area of the second end is less than a cross-sectional area of the first end. The system is configured such that air passing through the air channel is configured to pass from the air inlet, into the aerosol-generating region, through the aerosol outlet tube, past the air channel seal and then out from the outlet.

In such an aerosol provision system, the air channel, the heating element, the aerosol outlet tube and the air channel seal may form part of a cartridge as described above. Alternatively, the air channel, the heating element, the aerosol outlet tube and the air channel seal may form part of an aerosol delivery device for use with a cartridge. In this case, the air channel, the heating element, the aerosol outlet tube and the air channel seal may be are characterized according to the features described herein.