Patent Description:
Electronic vapour provision systems such as electronic cigarettes (e-cigarettes) generally contain a vapour 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 a vapour is generated for inhalation by a user, for example through heat vaporisation. Thus, a vapour provision system will typically comprise a vaporiser, e.g. a heating element, arranged to vaporise a portion of precursor material to generate a vapour in a vapour generation region of an air channel through the vapour provision system. As a user inhales on the device and electrical power is supplied to the vaporiser, air is drawn into the device through one or more inlet holes and along the air channel to the vapour generation region, where the air mixes with the vaporised precursor material and forms a condensation aerosol. The air drawn through the vapour 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 vapour provision systems to comprise a modular assembly, often having two main functional parts, namely a control unit and disposable / replaceable cartridge part. Typically the cartridge part will comprise the consumable vapour precursor material and the vaporiser (atomiser), while the control unit part will comprise longer-life items, such as a rechargeable battery, device control circuitry, activation sensors and user interface features. The control unit 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 cartomiser.

The control unit 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 vapour precursor material in a cartridge has been exhausted, or the user wishes to switch to a different cartridge having a different vapour precursor material, the cartridge may be removed from the control unit and a replacement cartridge may be attached to the device in its place.

A potential drawbacks for cartridges containing liquid vapour 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 vaporiser located in an air path / channel connecting from an air inlet to a vapour 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 control unit may damage the control unit, for example due to corrosion. Some approaches to reduce the risk of leakage may involve restricting the flow of liquid to the vaporiser, 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 vaporiser (dry-out), which can give rise to overheating and undesirable flavours.

<CIT> discloses an electronic cigarette with a cartridge and an atomizer assembly.

The cartridge has a chimney and a liquid reservoir with an opening. The atomizer assembly includes an atomizer sleeve; a liquid conductor plugging the opening, a base axially abuts against the liquid conductor, and a heating element positioned between the liquid conductor and the base; the liquid conductor, the base and the heating element are received in the atomizer sleeve. The atomizer sleeve defines an air channel. The base defines an aperture communicated to the air channel. The heating element includes a linear wick and a heating wire twined around the wick. The wick without being twined by the heating wire is received in the aperture. The liquid conductor defines an outlet hole for transferring liquid to the wire. The heating wire and the wick are positioned in the air channel.

<CIT> discloses an atomizing component and an electronic cigarette. A first e-liquid storage cavity is used for storing an e-liquid. When a button mechanism is being pressed, the e-liquid in the first e-liquid storage cavity flows into a second e-liquid storage cavity.

<CIT> discloses another detachable cartridge for a vapour provision system. Various approaches are described herein which seek to help address or mitigate some of the issues discussed above.

The invention is defined in the appended independent claim. Preferred embodiments are matter of the dependent claims.

According to a first aspect of certain embodiments there is provided a cartridge for a vapour provision system comprising the cartridge and a control unit, wherein the cartridge comprises: a housing part having a mouthpiece end and an interface end, wherein the mouthpiece end includes a vapour outlet for the cartridge and the interface end includes an interface for coupling the cartridge to a control unit; an air channel extending from an air inlet in the housing part to the vapour outlet; a reservoir within the housing part containing liquid for vaporisation, wherein an end of the reservoir at the interface end of the housing part is sealed by a resilient plug, wherein the reservoir includes a dividing wall between a first reservoir region on a side of the dividing wall facing the mouth piece end of the housing part and a second reservoir region on a side of the dividing wall facing the interface end of the housing part, wherein the second reservoir region is defined by a space between the air channel and an outer wall of the resilient plug, and wherein the dividing wall comprises at least one fluid communication opening to provide fluid communication between the first reservoir region and the second reservoir region; and a liquid transport element arranged to transport liquid from the second region of the reservoir to a vaporiser for generating vapour in a vapour generation region for user inhalation.

According to a second aspect of certain embodiments there is provided a vapour provision system comprising the cartridge of the above-mentioned first aspect of certain embodiments and a control unit, wherein the control unit comprises a cartridge receiving section that includes an interface arranged to cooperatively engage with the interface at the interface end of the cartridge so as to releasably couple the cartridge to the control unit, wherein the control unit further comprises a power supply and control circuitry configured to selective supply power from the power supply to the vaporiser in the cartridge via their cooperatively engaging interfaces.

It will be appreciated that features and aspects of the invention described above in relation to the various aspects of the invention are equally applicable to, and may be combined with, embodiments of the invention according to other aspects of the invention as appropriate, and not just in the specific combinations described herein.

The present disclosure relates to vapour 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 vapour provision system / device and electronic vapour provision system / device. Furthermore, and as is common in the technical field, the terms "vapour" and "aerosol", and related terms such as "vaporise" and "aerosolise", may generally be used interchangeably.

As noted above, vapour provision systems (e-cigarettes) often comprise a modular assembly including both a reusable part (control unit) 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.

<FIG> is a schematic perspective view of an example vapour provision system / device (e-cigarette) <NUM> in 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 in <FIG> (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-cigarette <NUM> comprises two main components, namely a cartridge <NUM> and a control unit <NUM>. The control unit <NUM> and the cartridge <NUM> are shown separated in <FIG>, but are coupled together when in use.

The cartridge <NUM> and control unit <NUM> are 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 the example electronic cigarette <NUM> represented in <FIG>, the cartridge comprises a mouthpiece end <NUM> and an interface end <NUM> and is coupled to the control unit by inserting an interface end portion <NUM> at the interface end of the cartridge into a corresponding receptacle <NUM> / receiving section of the control unit. The interface end portion <NUM> of the cartridge is a close fit to be receptacle <NUM> and includes protrusions <NUM> which engage with corresponding detents in the interior surface of a receptacle wall <NUM> defining the receptacle <NUM> to provide a releasable mechanical engagement between the cartridge and the control unit. An electrical connection is established between the control unit and the cartridge via a pair of electrical contacts on the bottom of the cartridge (not shown in <FIG>) and corresponding sprung contact pins in the base of the receptacle <NUM> (not shown in <FIG>). 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 a control unit 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 cigarette <NUM> has a generally elongate shape extending along a longitudinal axis L. When the cartridge is coupled to the control unit, the overall length of the electronic cigarette in this example (along the longitudinal axis) is around <NUM>. The overall length of the control unit is around <NUM> and the overall length of the cartridge is around <NUM> (i.e. there is around <NUM> of overlap between the interface end portion <NUM> of the cartridge and the receptacle <NUM> of the control unit when they are coupled together). The electronic cigarette has a cross-section which is generally oval and which is largest around the middle of the electronic cigarette and tapers in a curved manner towards the ends. The cross-section around the middle of the electronic cigarette has a width of around <NUM> and a thickness of around <NUM>. The end of the cartridge has a width of around <NUM> and a thickness of around <NUM>, whereas the other end of the electronic cigarette has a width of around <NUM> and a thickness of around <NUM>. The outer housing of the electronic cigarette is in this example is formed from plastic. 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 control unit <NUM> may in accordance with certain embodiments of the disclosure be broadly conventional in terms of its functionality and general construction techniques. In the example of <FIG>, the control unit <NUM> comprises a plastic outer housing <NUM> including the receptacle wall <NUM> that defines the receptacle <NUM> for receiving the end of the cartridge as noted above. The outer housing <NUM> of the control unit <NUM> in this example has a generally oval cross section conforming to the shape and size of the cartridge <NUM> at their interface to provide a smooth transition between the two parts. The receptacle <NUM> and the end portion <NUM> of the cartridge <NUM> are symmetric when rotated through <NUM> ° so the cartridge can be inserted into the control unit in two different orientations. The receptacle wall <NUM> includes two control unit air inlet openings <NUM> (i.e. holes in the wall). These openings <NUM> are positioned to align with an air inlet <NUM> for the cartridge when the cartridge is coupled to the control unit. A different one of the openings <NUM> aligns with the air inlet <NUM> of 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 control unit in only one orientation while other implementations may have a higher degree of rotational symmetry such that the cartridge is couplable to the control unit in more orientations.

The control unit further comprises a battery <NUM> for providing operating power for the electronic cigarette, control circuitry <NUM> for controlling and monitoring the operation of the electronic cigarette, a user input button <NUM>, an indicator light <NUM>, and a charging port <NUM>.

The battery <NUM> in 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 battery <NUM> may be recharged through the charging port <NUM>, which may, for example, comprise a USB connector.

The input button <NUM> in 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 vapour 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 vapour generation.

The indicator light <NUM> is 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 colours and / or different flash sequences in accordance with generally conventional techniques.

The control circuitry <NUM> is 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) <NUM> may 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 circuitry <NUM> may 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 circuitry <NUM> can 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> is an exploded schematic perspective view of the cartridge <NUM> (exploded along the longitudinal axis L). The cartridge <NUM> comprises a housing part <NUM>, an air channel seal <NUM>, a dividing wall element <NUM>, an outlet tube <NUM>, a vaporiser <NUM>, a liquid transport element <NUM>, a resilient plug <NUM>, and an end cap <NUM> with contact electrodes <NUM>. <FIG> schematically represents some of these components in more detail.

<FIG> is a schematic cut-away view of the housing part <NUM> through the longitudinal axis L where the housing part <NUM> is thinnest. <FIG> is a schematic cut-away view of the housing part <NUM> through the longitudinal axis L where the housing part <NUM> is widest. <FIG> is a schematic view of the housing part along the longitudinal axis L from the interface end <NUM> (i.e. viewed from below in the orientation of <FIG>).

<FIG> is a schematic perspective view of the dividing wall element <NUM> as seen from below. <FIG> is a schematic cross-section through an upper part of the dividing wall element <NUM> as viewed from below.

<FIG> is a schematic perspective view of the resilient plug <NUM> from above and <FIG> is a schematic perspective view of the resilient plug <NUM> from below. <FIG> is a schematic view of the resilient plug <NUM> along the longitudinal axis L seen from the mouthpiece end <NUM> of the cartridge (i.e. viewed from above for the orientation in <FIG> and <FIG>).

<FIG> is a schematic perspective view of the end cap <NUM> from above. <FIG> is a schematic view of the end cap <NUM> along the longitudinal axis L seen from the mouthpiece end <NUM> of the cartridge (i.e. from above).

The housing part <NUM> in this example comprises a housing outer wall <NUM> and a housing inner tube <NUM> which in this example are formed from a single moulding of polypropylene. The housing outer wall <NUM> defines the external appearance of the cartridge <NUM> and the housing inner tube <NUM> defines a part the air channel through the cartridge. The housing part is open at the interface end <NUM> of the cartridge and closed at the mouthpiece end <NUM> of the cartridge except for a mouthpiece opening / vapour outlet <NUM> in fluid communication with the housing inner tube <NUM>. The housing part <NUM> includes an opening in a sidewall which provides the air inlet <NUM> for the cartridge. The air inlet <NUM> in this example has an area of around <NUM><NUM>. The outer surface of the outer wall <NUM> of the housing part <NUM> includes the protrusions <NUM> discussed above which engage with corresponding detents in the interior surface of the receptacle wall <NUM> defining the receptacle <NUM> to provide a releasable mechanical engagement between the cartridge and the control unit. The inner surface of the outer wall <NUM> of the housing part includes further protrusions <NUM> which act to provide an abutment stop for locating the dividing wall element <NUM> along the longitudinal axis L when the cartridge is assembled. The outer wall <NUM> of the housing part <NUM> further comprises holes which provide latch recesses <NUM> arranged to receive corresponding latch projections <NUM> in the end cap to fix the end cap to be housing part when the cartridge is assembled.

The outer wall <NUM> of the housing part <NUM> includes a double-walled section <NUM> that defines a gap <NUM> in fluid communication with the air inlet <NUM>. The gap <NUM> provides a portion of the air channel through the cartridge. In this example the doubled-walled section <NUM> of the housing part <NUM> is arranged so the gap defines an air channel running within the housing outer wall <NUM> parallel to the longitudinal axis with a cross-section in a plane perpendicular to the longitudinal axis of around <NUM><NUM>. The gap / portion of air channel <NUM> defined by the double-walled section of the housing part extends down to the open end of the housing part <NUM>.

The air channel seal <NUM> is a silicone moulding generally in the form of a tube having a through hole <NUM>. The outer wall of the air channel seal <NUM> includes circumferential ridges <NUM> and an upper collar <NUM>. The inner wall of the air channel seal <NUM> also includes circumferential ridges, but these are not visible in <FIG>. When the cartridge is assembled the air channel seal <NUM> is mounted to the housing inner tube <NUM> with an end of the housing inner tube <NUM> extending partly into the through hole <NUM> of the air channel seal <NUM>. The through hole <NUM> in the air channel seal has a diameter of around <NUM> in its relaxed state whereas the end of the housing inner tube <NUM> has a diameter of around <NUM> so that a seal is formed when the air channel seal <NUM> is stretched to accommodate the housing inner tube <NUM>. This seal is facilitated by the ridges on the inner surface of the air channel seal <NUM>.

The outlet tube <NUM> comprises a tubular section of ANSI <NUM> stainless steel with an internal diameter of around <NUM> and a wall thickness of around <NUM>. The bottom end of the outlet tube <NUM> includes a pair of diametrically opposing slots <NUM> with an end of each slot having a semi-circular recess <NUM>. When the cartridge is assembled the outlet tube <NUM> mounts to the outer surface of the air channel seal <NUM>. The outer diameter of the air channel seal is around <NUM> in its relaxed state so that a seal is formed when the air channel seal <NUM> is compressed to fit inside the outlet tube <NUM>. This seal is facilitated by the ridges <NUM> on the outer surface of the air channel seal <NUM>. The collar <NUM> on the air channel seal <NUM> provides a stop for the outlet tube <NUM>.

The liquid transport element <NUM> comprises a capillary wick and the vaporiser <NUM> comprises a resistance wire heater wound around the capillary wick. In addition to the portion of the resistance wire wound around the capillary wick, the vaporiser comprises electrical leads <NUM> which pass through holes in the resilient plug <NUM> to contact electrodes <NUM> mounted to the end cap <NUM> to allow power to be supplied to the vaporiser via the electrical interface established when the cartridge is connected to a control unit. The vaporiser leads <NUM> may 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 this example the heater coil <NUM> comprises a nickel iron alloy wire and the wick <NUM> comprises a glass fibre bundle. The vaporiser 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 vaporiser is not of primary significance to the principles described herein.

When the cartridge is assembled, the wick <NUM> is received in the semi-circular recesses <NUM> of the outlet tube <NUM> so that a central portion of the wick about which the heating coil is wound is inside the outlet tube while end portions of the wick are outside the outlet tube <NUM>.

The resilient plug <NUM> in this example comprises a single moulding of silicone. The resilient plug comprises a base part <NUM> with an outer wall <NUM> extending upwardly therefrom (i.e. towards the mouthpiece end of the cartridge). The resilient plug further comprises an inner wall <NUM> extending upwardly from the base part <NUM> and surrounding a through hole <NUM> through the base part <NUM>.

The outer wall <NUM> of the resilient plug <NUM> conforms to an inner surface of the housing part <NUM> so that when the cartridge is assembled the resilient plug in <NUM> forms a seal with the housing part <NUM>. The inner wall <NUM> of the resilient plug <NUM> conforms to an inner surface of the outlet tube <NUM> so that when the cartridge is assembled the resilient plug <NUM> also forms a seal with the outlet tube <NUM>. The inner wall <NUM> includes a pair of diametrically opposing slots <NUM> with the end of each slot having a semi-circular recess <NUM>. Extended outwardly (i.e. in a direction away from the longitudinal axis of the cartridge) from the bottom of each slot in the inner wall <NUM> is a cradle section <NUM> shaped to receive a section of the liquid transport element <NUM> when the cartridge is assembled. The slots <NUM> and semi-circular recesses <NUM> provided by the inner wall of the resilient plug <NUM> and the slots <NUM> and semi-circular recesses <NUM> of the outlet tube <NUM> are aligned so that the slots <NUM> in the outlet tube <NUM> accommodate respective ones of the cradles <NUM> with the respective semi-circular recesses in the outlet tube and resilient plug cooperating to define holes through which the liquid transport element passes. The size of the holes provided by the semi-circular recesses through which the liquid transport element passes correspond closely to the size and shape of the liquid transport element, but are slightly smaller so a degree of compression is provided by the resilience of the resilient plug <NUM>. This allows liquid to be transported along the liquid transport element by capillary action while restricting the extent to which liquid which is not transported by capillary action can pass through the openings. As noted above, the resilient plug <NUM> includes further openings <NUM> in the base part <NUM> through which the contact leads <NUM> for the vaporiser pass when the cartridge is assembled. The bottom of the base part of the resilient plug includes spacers <NUM> which maintain an offset between the remaining surface of the bottom of the base part and the end cap <NUM>. These spacers <NUM> include the openings <NUM> through which the electrical contact leads <NUM> for the vaporiser pass.

The end cap <NUM> comprises a polypropylene moulding with a pair of gold-plated copper electrode posts <NUM> mounted therein.

The ends of the electrode posts <NUM> on the bottom side of the end cap are close to flush with the interface end <NUM> of the cartridge provided by the end cap <NUM>. 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 cap <NUM> and into the holes <NUM> in the resilient plug <NUM> through which the contact leads <NUM> pass. The electrode posts are slightly oversized relative to the holes <NUM> and include a chamfer at their upper ends to facilitate insertion into the holes <NUM> in the resilient plug where they are maintained in pressed contact with the contact leads for the vaporiser by virtue of the resilient nature of the resilient plug.

The end cap has a base section <NUM> and an upstanding wall <NUM> which conforms to the inner surface of the housing part <NUM>. The upstanding wall <NUM> of the end cap <NUM> is inserted into the housing part <NUM> so the latch projections <NUM> engage with the latch recesses <NUM> in the housing part <NUM> to snap-fit the end cap <NUM> to the housing part when the cartridge is assembled. The top of the upstanding wall <NUM> of the end cap <NUM> abuts a peripheral part of the resilient plug <NUM> and the lower face of the spacers <NUM> on the resilient plug also abut the base section <NUM> of the resilient plug so that when the end cap <NUM> is attached to the housing part it presses against the resilient part <NUM> to maintain it in slight compression.

The base portion <NUM> of the end cap <NUM> includes a peripheral lip <NUM> beyond the base of the upstanding wall <NUM> with a thickness which corresponds with the thickness of the outer wall of the housing part at the interface end of the cartridge. The end cap also includes an upstanding locating pin <NUM> which aligns with a corresponding locating hole <NUM> in the resilient plug to help establish their relative location during assembly.

The dividing wall element <NUM> comprises a single moulding of polypropylene and includes a dividing wall <NUM> and a collar <NUM> formed by projections from the dividing wall <NUM> in the direction towards the interface end of the cartridge. The dividing wall element <NUM> has a central opening <NUM> through which the outlet tube <NUM> passes (i.e. the dividing wall is arranged around the outlet tube <NUM>). When the cartridge is assembled, the upper surface of the outer wall <NUM> of the resilient plug <NUM> engages with the lower surface of the dividing wall <NUM>, and the upper surface of the dividing wall <NUM> in turn engages with the projections <NUM> on the inner surface of the outer wall <NUM> of the housing part <NUM>. Thus, the dividing wall <NUM> prevents the resilient plug from being pushed too far into the housing part <NUM> - i.e. the dividing wall <NUM> is fixedly located along the longitudinal axis of the cartridge by the protrusions <NUM> in the housing part and so provides the resilient plug with a fixed surface to push against. The collar <NUM> formed by projections from the dividing wall includes a first pair of opposing projections / tongues <NUM> which engage with corresponding recesses on an inner surface of the outer wall <NUM> of the resilient plug <NUM>. The protrusions from the dividing wall <NUM> further provide a pair of cradle sections <NUM> configured to engage with corresponding ones of the cradle sections <NUM> in the resilient part <NUM> when the cartridge is assembled to further define the opening through which the liquid transport element passes.

When the cartridge is assembled an air channel extending from the air inlet <NUM> to the vapour outlet <NUM> through the cartridge is formed. Starting from the air inlet <NUM> in the side wall of the housing part <NUM>, a first section of the air channel is provided by the gap <NUM> formed by the double-walled section <NUM> in the outer wall <NUM> of the housing part <NUM> and extends from the air inlet <NUM> towards the interface end <NUM> of the cartridge and past the resilient plug <NUM>. A second portion of the air channel is provided by the gap between the base of the resilient plug <NUM> and the end cap <NUM>. A third portion of the air channel is provided by the hole <NUM> through the resilient plug <NUM>. A fourth portion of the air channel is provided by the region within the inner wall <NUM> of the resilient plug and the outlet tube around the vaporiser <NUM>. This fourth portion of the air channel may also be referred to as a vapour generation region, it being the primary region in which vapour is generated during use. The air channel from the air inlet <NUM> to the vapour generation region may be referred to as an air inlet section of the air channel. A fifth portion of the air channel is provided by the remainder of the outlet tube <NUM>. A sixth portion of the air channel is provided by the outer housing inner tube <NUM> which connects the air channel to the vapour outlet <NUM>. The air channel from the vapour generation region to be the vapour outlet may be referred to as a vapour outlet section of the air channel.

Also, when the cartridge is assembled a reservoir for liquid is formed by the space outside the air channel and inside the housing part <NUM>. 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 reservoir is closed at the interface end of the cartridge by the resilient plug <NUM>. The reservoir includes a first region above the dividing wall <NUM> and a second region below the dividing wall <NUM> within the space formed between the air channel and the outer wall of the resilient plug. The liquid transport element (capillary wick) <NUM> passes through openings in the wall of the air channel provided by the semi-circular recesses <NUM>, <NUM> in the resilient plug <NUM> and the outlet tube <NUM> and the cradle sections <NUM>, <NUM> in the resilient plug <NUM> and the dividing wall element <NUM> that engage with one another as discussed above. Thus, the ends of the liquid transport element extend into the second region of the reservoir from which they draw liquid through the openings in the air channel to the vaporiser <NUM> for subsequent vaporisation.

In normal use, the cartridge <NUM> is coupled to the control unit <NUM> and the control unit activated to supply power to the cartridge via the contact electrodes <NUM> in the end cap <NUM>. Power then passes through the connection leads <NUM> to the vaporiser <NUM>. The vaporiser is thus electrically heated and so vaporises a portion of the liquid from the liquid transport element in the vicinity of the vaporiser. This generates vapour in the vapour generation region of the air path. Liquid that is vaporised from the liquid transport element is replaced by more liquid drawn from the reservoir by capillary action. While the vaporiser is activated, a user inhales on the mouthpiece end <NUM> of the cartridge. This causes air to be drawn through whichever control unit air inlet <NUM> aligns with the air inlet <NUM> of the cartridge (which will depend on the orientation in which the cartridge was inserted into the control unit receptacle <NUM>). Air then enters the cartridge through the air inlet <NUM>, passes along the gap <NUM> in the double-walled section <NUM> of the housing part <NUM>, passes between the resilient plug <NUM> and the end cap <NUM> before entering the vapour generation region surrounding the vaporiser <NUM> through the hole <NUM> in the base part <NUM> of the resilient plug <NUM>. The incoming air mixes with vapour generated from the vaporiser to form a condensation aerosol, which is then drawn along the outlet tube <NUM> and the housing part inner <NUM> before exiting through the mouthpiece outlet/vapour outlet <NUM> for user inhalation.

Thus in accordance with certain embodiments of the disclosure, a cartridge for a vapour provision system may generally comprise a housing part having a mouthpiece end and an interface end, wherein the mouthpiece end includes a vapour outlet for the cartridge and the interface end includes an interface for coupling the cartridge to a control unit. An air channel wall (which may be formed by various components of the cartridge) extends from an air inlet for the cartridge to the vapour outlet via a vapour generation region in the vicinity of a vaporiser. The cartridge has a reservoir within the housing part containing liquid for vaporisation. The reservoir is defined by a region within the housing part which is outside the air channel and an end of the reservoir at the interface end of the housing part is sealed by a resilient plug comprising a base part and an outer wall, wherein the outer wall of the resilient plug forms a seal with an inner surface of the housing part. Respective ends of a liquid transport element pass through opening in the air channel or into the reservoir so as to convey liquid from the reservoir to the vaporiser.

One aspect of some particular cartridge configurations in accordance with certain embodiments of the disclosure is the manner in which the resilient plug <NUM> provides a seal to the housing part <NUM>. In particular, in accordance with some example implementations the outer wall <NUM> of the resilient plug <NUM> which seals to the inner surface of the housing part <NUM> to form the end of the liquid reservoir extends in direction parallel to the longitudinal axis of the cartridge to a position which is further from the interface end of the cartridge than the liquid transport element / vaporiser. That is to say, the ends of the liquid transport element extends into the liquid reservoir in a region which is surrounded by the outer sealing wall of the resilient plug. Not only does this help seal the reservoir against leakage, it allows the geometry of the reservoir in the region which supplies the liquid transport element with liquid to be governed by the geometry of the resilient plug. For example, the radial thickness of the reservoir in this region can readily be made smaller than the radial thickness in other longitudinal positions along the air channel, which can help trap liquid in the vicinity of the liquid transport element, thereby helping to reduce the risk of dry out for different orientations of the cartridge during use.

The outer wall of the resilient plug may, for example, contact the inner surface of the housing part at locations over a distance of at least <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> in a direction extending from the interface end to the mouthpiece end (i.e. parallel to the longitudinal axis). The outer wall of the resilient plug may be in contact with the inner surface of the housing over the majority of this distance, or the outer wall of the resilient plug may include a number of (e.g. four) circumferential ridges <NUM> to help improve sealing. The resilient plug may be slightly oversized relative to the opening in the housing part so that it is biased into slight compression. For example, for the implementation shown in <FIG>, the interior width of the housing part into which the resilient plug is inserted in the plane of this figure is around <NUM>, whereas the corresponding width of the resilient plug is around <NUM>, thereby placing the resilient plug into compression when inserted into the housing part. As can be most readily seen in <FIG>, whereas the outer cross section of the cartridge housing part is symmetric under a <NUM>° rotation, the resilient plug <NUM> does not have the same symmetry because it includes a flat <NUM> on one side to accommodate the air channel gap <NUM> provided by the double-walled section <NUM> of the housing part (i.e. the resilient plug is asymmetric in a plane perpendicular to a longitudinal axis of the cartridge to accommodate the double-walled section of the housing part).

In terms of the radial size / width of the reservoir in the annular region where the liquid transport element extends into the reservoir, a distance between the air channel wall and the outer wall of the resilient plug in this region may, for example, be in the range <NUM> to <NUM>. In the example cartridge discussed above which has a generally oval housing part and a generally circular air channel, it will be appreciated the thickness of the reservoir is different at different locations around the air channel. In this example the liquid transport element is arranged to extend into the reservoir in the region where it is widest in the axial direction, i.e. into the "lobes" of the oval reservoir around the air channel. The portions of the liquid transport element that extend into the reservoir may, for example, have a length, as measured from the interior of the air channel wall, in the range <NUM> to <NUM>, e.g. in the range <NUM> to <NUM> or in the range <NUM> to <NUM>. The specific geometry in this regard (and for other aspects of the configuration) may be chosen having regard to a desired rate of liquid transport, for example having regard to the capillary strength of the liquid transport element and the viscosity of the liquid, and may be established for a given cartridge design through modelling or empirical testing.

Another aspect of some particular cartridge configurations in accordance with certain embodiments of the disclosure is the manner in which the air channel is routed through the cartridge, and in particular from the air inlet to the vicinity of the vaporiser (the vapour generation region). In particular, whereas in a conventional cartridges an air inlet is typically provided at the interface end of the cartridge, in accordance with certain embodiments of the disclosure, an air inlet for the cartridge is located in a side wall of the housing part at a position which is further from the interface end than at least a part of the resilient plug that seals an end of the reservoir. Thus, the air channel in the cartridge is initially routed from the air inlet towards the interface end and bypasses the resilient plug before changing direction and entering the vapour generation chamber through the resilient plug. This can allow the outer surface of the cartridge at the interface end, where it is closest to the vaporiser, to be closed, thereby helping to reduce the risk of leakage from the cartridge, both in terms of liquid coming through the openings in the air channel which is not retained by the liquid transport element in the air channel (e.g. due to saturation / agitation) or liquid that has being vaporised but condensed back to liquid in the air channel during use. In some implementations, a distance from air inlet to the interface end of the housing part may be at least <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or <NUM>.

In some example implementations an absorbent element, for example a portion of sponge material or a series of channels forming a capillary trap, may be provided between the air inlet and the vapour generation chamber, for example in the region air channel formed between the base of the resilient plug and the end cap, to further help reduce the risk of leakage by absorbing liquid that forms in the air channel and so helping prevent the liquid travelling around the air channel through the air inlet or towards the vapour outlet.

In some example implementations the air channel from the air inlet to the vapour outlet may have its smallest cross-sectional area where it passes through the hole <NUM> in the resilient plug. That is to say, the hole in the resilient plug may be primarily responsible for governing the overall resistance to draw for the electronic cigarette.

Another aspect of some particular cartridge configurations in accordance with certain embodiments of the disclosure is the manner in which the dividing wall element divides the air reservoir into two regions, namely a main region above the dividing wall (i.e. towards a mouthpiece end of the cartridge) and a liquid-supply region below the dividing wall (i.e. on the same side of the dividing wall as where the liquid transport element extends from the vaporiser into the reservoir). The dividing wall includes openings to govern the flow of liquid on the main region to the liquid supply region. The dividing wall can help retain liquid in the liquid supply region of the reservoir, example when the electronic cigarette is tilted through various orientations, which can help avoid dry out. The dividing wall can also conveniently provide a mechanical stop for the resilient plug to abut / press against so as to help correctly locate the resilient plug during assembly and maintain the resilient plug in slight compression between the dividing wall and the end cap when the cartridge is assembled.

In the example discussed above, the dividing wall is formed as a separate element form the housing part, wherein an inner surface of the housing part includes one or more protrusions arranged to contact the side of the dividing wall facing the mouthpiece end of the cartridge to locate the dividing wall along a longitudinal axis of the cartridge, but in other examples the dividing wall may be integrally formed with the housing part.

In the example discussed above the dividing wall is in the form of an annular band around the air channel and comprises four fluid communication openings <NUM> located in respective quadrants of the band. However, more or fewer openings through the dividing wall may be provided in different implementations. Individual openings may, for example, have an area of between <NUM><NUM> and <NUM><NUM>.

A combined area for the at least one openings as a fraction of the total area of the dividing wall exposed to liquid supply region of the reservoir region may be, for example, from <NUM>% to <NUM>%; <NUM>% to <NUM>% or <NUM>% to <NUM>%.

It will be appreciated that while the above description has focused on some specific cartridge configurations comprising a number of different features, cartridges in accordance with other embodiments of the disclosure may not include all these features. For example, in some implementations an air path generally of the kind discussed above, i.e. with an air inlet which is in a sidewall of the cartridge and closer to the mouthpiece end of the cartridge than the vaporiser, may be provided in a cartridge which does not include a resilient plug with an outer sealing wall which extends around the vaporiser and / or does not include a dividing wall element of the kind discussed above. Similarly, a cartridge which does include a resilient plug with an outer sealing wall which extends around the vaporiser may have an air inlet into the cartridge which is at the interface end of the cartridge, and not in a sidewall, and which may also not have a dividing wall element of the kind discussed above. Furthermore, a cartridge which does include a dividing wall element, might not include an air inlet located further from the interface end of the cartridge than the vaporiser and / or an extended outer sealing wall for a resilient plug as discussed above.

Thus, there has been described a cartridge for a vapour provision system comprising the cartridge and a control unit, wherein the cartridge comprises: a housing part having a mouthpiece end and an interface end, wherein the mouthpiece end includes a vapour outlet for the cartridge and the interface end includes an interface for coupling the cartridge to the control unit; an air channel extending from an air inlet for the cartridge to the vapour outlet, wherein the air channel is defined by an air channel wall; a reservoir within the housing part for liquid for vaporisation, wherein an end of the reservoir at the interface end of the housing part is sealed by a resilient plug comprising a base part and an outer wall extending away from the base part towards the mouthpiece end of the housing part, wherein the outer wall of the resilient plug forms a seal with an inner wall of the housing part; a vaporiser for vaporising liquid from the reservoir to generate vapour in a vapour generation region of the air channel for user inhalation; and a liquid transport element for transporting liquid from the reservoir to the vaporiser through an opening in the air channel wall, wherein the opening in the air channel wall is located nearer to the base part of the resilient plug than the top of the outer wall of the resilient plug so that a portion of the liquid transport element extends into the reservoir in a region surrounded by the outer wall of the resilient plug.

There has also been described a cartridge for a vapour provision system comprising the cartridge and a control unit, wherein the cartridge comprises: a housing part having a mouthpiece end and an interface end connected by a side wall, wherein the mouthpiece end includes a vapour outlet for the cartridge and the interface end includes an interface for coupling the cartridge to a control unit; an air channel extending from an air inlet for the cartridge to the vapour outlet; a reservoir within the housing part containing liquid for vaporisation, wherein an end of the reservoir at the interface end of the housing part is sealed by a resilient plug, and wherein an outer wall of the resilient plug forms a seal with an inner surface of the housing part; a vaporiser for vaporising liquid from the reservoir to generate vapour in a vapour generation region of the air channel; and a liquid transport element for transporting liquid from the reservoir to the vaporiser; wherein the air inlet for the cartridge is located in the side wall of the housing part at a position which is further from the interface end than at least a part of the resilient plug.

There has also been described a cartridge for a vapour provision system comprising the cartridge and a control unit, wherein the cartridge comprises: a housing part having a mouthpiece end and an interface end, wherein the mouthpiece end includes a vapour outlet for the cartridge and the interface end includes an interface for coupling the cartridge to a control unit; an air channel extending from an air inlet in the housing part to the vapour outlet; a reservoir within the housing part containing liquid for vaporisation, wherein an end of the reservoir at the interface end of the housing part is sealed by a resilient plug, wherein the reservoir includes a dividing wall between a first reservoir region on a side of the dividing wall facing the mouth piece end of the housing part and a second reservoir region on a side of the dividing wall facing the interface end of the housing part, wherein the dividing wall comprises at least one fluid communication opening to provide fluid communication between the first reservoir region and the second reservoir region; and a liquid transport element arranged to transport liquid from the second region of the reservoir to a vaporiser for generating vapour in a vapour generation region for user inhalation.

While the above described embodiments have in some respects focussed on some specific example vapour provision systems, it will be appreciated the same principles can be applied for vapour provision systems using other technologies. That is to say, the specific manner in which various aspects of the vapour provision system function, for example in terms of the underlying form of the vaporiser or vaporiser technology used are not directly relevant to the principles underlying the examples described herein.

Claim 1:
A cartridge (<NUM>) for a vapour provision system (<NUM>) comprising the cartridge and a control unit (<NUM>), wherein the cartridge comprises:
a housing part (<NUM>) having a mouthpiece end (<NUM>) and an interface end (<NUM>), wherein the mouthpiece end includes a vapour outlet (<NUM>) for the cartridge and the interface end includes an interface for coupling the cartridge to a control unit;
an air channel extending from an air inlet (<NUM>) in the housing part to the vapour outlet;
a reservoir within the housing part containing liquid for vaporisation, wherein an end of the reservoir at the interface end of the housing part is sealed by a resilient plug (<NUM>), wherein the reservoir includes a dividing wall (<NUM>) between a first reservoir region on a side of the dividing wall facing the mouth piece end of the housing part and a second reservoir region on a side of the dividing wall facing the interface end of the housing part, wherein the second reservoir region is defined by a space between the air channel and an outer wall of the resilient plug, and wherein the dividing wall comprises at least one fluid communication opening (<NUM>) to provide fluid communication between the first reservoir region and the second reservoir region; and
a liquid transport element (<NUM>) arranged to transport liquid from the second region of the reservoir to a vaporiser (<NUM>) for generating vapour in a vapour generation region for user inhalation.