Patent Description:
Electronic aerosol provision systems such as electronic cigarettes (e-cigarettes) generally contain an aerosol (or vapour) precursor / forming material, such as a reservoir of a source liquid containing a formulation, typically comprising a base liquid with additives such as nicotine and often flavourants, and / or a solid material such as a tobacco-based product, from which an aerosol is generated, e.g. through heat vaporisation. Thus, an aerosol provision system will typically comprise an aerosol generation chamber containing an atomiser (or vaporiser), e.g. a heating element, arranged to vaporise a portion of precursor material to generate an aerosol in the aerosol generation chamber. As a user inhales on the device and electrical power is supplied to the heating element, air is drawn into the device through inlet holes and into the aerosol generation chamber where the air mixes with the vaporised precursor material to form an aerosol. There is a flow path connecting the aerosol generation chamber with an opening in the mouthpiece so the incoming air drawn through the aerosol generation chamber continues along the flow path to the mouthpiece opening, carrying some of the vapour with it, and out through the mouthpiece opening for inhalation by the user.

Aerosol provision systems may comprise a modular assembly including both reusable and replaceable cartridge parts. Typically a cartridge part will comprise the consumable aerosol precursor material and / or the vaporiser, while a reusable device part will comprise longer-life items, such as a rechargeable battery, device control circuitry, activation sensors and user interface features. The reusable part may also be referred to as a control unit or battery section and replaceable cartridge parts that include both a vaporiser and precursor material may also be referred to as cartomisers.

Some aerosol provision systems may include multiple aerosol sources which can be used to generate vapour / aerosol that is mixed and inhaled by a user. However, in some cases, a user may desire a more flexible system in terms of the composition of the aerosol that is delivered to the user and/or how the aerosol is delivered.

Various approaches are described which seek to help address some of these issues. <CIT> discloses an electronic nicotine delivery system comprising a mouth piece, an atomizer arrangement, a power supply, a nicotine container, an additive container, the atomizer arrangement comprising an inlet from the nicotine container and an inlet from the additive container, the atomizer arrangement comprising two separate atomizers, a first atomizer and a second atomizer, the first atomizer producing nicotine-containing aerosols having a first mass median aerodynamic diameter and the second atomizer producing additive-containing aerosols having a second mass median aerodynamic diameter and wherein the second mass median aerodynamic diameter is greater than the first mass median aerodynamic diameter, the atomizers being electrically connected to the power supply. Furthermore, a method of producing a mixture of aerosols, an aerosol mixture and a use of an electronic nicotine delivery system is disclosed.

<CIT> discloses a device having at least two chambers for receiving vaporizable components, two heating elements, and circuitry to control heater behaviour. In some implementations, the device further comprises a mouthpiece chamber into which one or more flows from various channels are permitted to mix.

According to a first aspect of certain embodiments there is provided an aerosol provision device for generating aerosol for user inhalation, the aerosol provision device comprising: a first aerosol generating area and a second aerosol generating area each for receiving an aerosol precursor material; a mouthpiece from which a user inhales generated aerosol during use, wherein the mouthpiece comprises first and second mouthpiece openings; a first pathway extending from the first aerosol generating area to the first mouthpiece opening for transporting a first aerosol generated from the aerosol precursor material in the first aerosol generating area; and a second pathway extending from the second aerosol generating area to the second mouthpiece opening for transporting a second aerosol generated from the aerosol precursor material in the second aerosol generating area, wherein the first and second pathways are physically isolated from one another to prevent mixing of the first and second aerosols as the first and second aerosols are transported along the respective pathways.

According to a second aspect of certain embodiments there is provided an aerosol provision system for generating aerosol for user inhalation, the system comprising: the aerosol provision device of the first aspect; and a first and second aerosol precursor material, wherein the first aerosol precursor material is located in the first aerosol generating area and the second aerosol precursor is located in the second aerosol generating area.

According to a third aspect of certain embodiments there is provided a mouthpiece part for use with a control part for generating aerosol for user inhalation, wherein the control part comprises a first aerosol generating area for receiving a first aerosol precursor material and a second aerosol generating area for receiving a second aerosol precursor material, the control part configured to generate a first and second aerosol from the first and second aerosol precursor materials respectively, the mouthpiece part comprising: a first channel fluidly connected to a first mouthpiece opening through which the user inhales to receive the first aerosol when the mouthpiece part is coupled to the control part, wherein the first channel passes through the mouthpiece part; and a second channel fluidly connected to a second mouthpiece opening through which the user inhales to receive the second aerosol when the mouthpiece part is coupled to the control part, wherein the second channel passes through the mouthpiece part, wherein the first channel and the second channel are physically isolated from one another to prevent mixing of the first and second aerosols as the first and second aerosols are transported along the respective channels.

According to a fourth aspect of certain embodiments there is provided a kit of parts comprising a plurality of mouthpiece parts according to the third aspect, wherein each of the plurality of mouthpiece parts differs from the other in that at least one of the first and second channels is configured to alter the direction in which aerosol exits the mouthpiece opening and / or the properties of the aerosol as the aerosol exits the mouthpiece openings. According to a fifth aspect of certain embodiments there is provided an aerosol provision means for generating aerosol for user inhalation, the aerosol provision means comprising: a first storage means and a second storage means each for receiving an aerosol precursor material; a mouthpiece from which a user inhales generated aerosol during use, wherein the mouthpiece comprises first and second mouthpiece openings; a first pathway extending from the first storage means to the first mouthpiece opening for transporting a first aerosol generated from the aerosol precursor material in the first storage means; and a second pathway extending from the second storage means to the second mouthpiece opening for transporting a second aerosol generated from the aerosol precursor material in the second storage means, wherein the first and second pathways are physically isolated from one another to prevent mixing of the first and second aerosols as the first and second aerosols are transported along the respective pathways.

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; however, it will be appreciated this term may be used interchangeably with vapour provision system and electronic vapour provision system. Furthermore, and as is common in the technical field, the terms "vapour" and "aerosol", and related terms such as "vaporise", "volatilise" and "aerosolise", may also be used interchangeably. In this regard, means of generating an aerosol other than via a condensation aerosol are envisaged, such as atomization via vibrational, photonic, irradiative, electrostatic means etc..

<FIG> and <FIG> are highly schematic cross-sectional views of an example aerosol provision system <NUM> in accordance with some embodiments of the disclosure. <FIG> shows the aerosol provision system <NUM> in an assembled state while <FIG> shows the aerosol provision system1 in a disassembled state / partially exploded state. As will be discussed below, parts of the example aerosol provision system <NUM> are provided as removable / detachable from other parts of the aerosol provision system <NUM>.

With reference to <FIG> and <FIG>, the example aerosol provision system <NUM> comprises a control/device (or battery / reusable) part <NUM>, a detachable mouthpiece (or lid) part <NUM>, and, in this example, two aerosol generating components, such as cartomisers 4a and 4b, collectively referred to herein as cartomisers <NUM>. In use, the aerosol provision system <NUM> is configured to generate aerosol from the cartomisers <NUM> (by vaporising an aerosol precursor material) and deliver / provide the aerosol to a user through the mouthpiece part <NUM> as the user inhales through the mouthpiece part <NUM>. It should be appreciated that the aerosol provision system <NUM> includes the cartomisers <NUM> in addition to the control part <NUM> and mouthpiece part <NUM>. Strictly speaking, the term aerosol provision device refers to just the control/device part <NUM> and mouthpiece part <NUM> without the cartomisers <NUM>. However, to aid in the general explanation of the system disclosed, the terms "system" and "device" are used interchangeably herein to refer to either of the device including cartomisers and the device excluding cartomisers.

One aspect of the example aerosol provision system is the functionality of providing consistent delivery of aerosol to the user regardless of the state / configuration of the aerosol provision system. By this, and as will become apparent from below, it is meant that whether a user uses the device with multiple aerosol generating components, e.g. two cartomisers <NUM>, or only a single aerosol generating component, e.g., a single cartomiser <NUM>, the aerosol provision system is controlled to provide a consistent (or close to consistent) experience to the user. This may be in terms of the quantity of aerosol produced (i.e., the quantity / volume of aerosol inhaled) or by providing a generally consistent ratio of vapour to air (i.e., the percentage of vapour contained within the generated aerosol). That is, the quantity of aerosol produced or the ratio of vapour to air is the same (or approximately the same, e.g., within <NUM>%) whether the aerosol provision device has one or multiple aerosol generating components present in the aerosol generating areas. In some implementations, it should be appreciated that the quantity of aerosol produced may vary depending on the strength of the user's inhalation (or puff). For example a stronger puff may generate more aerosol as compared to a weaker puff. However, one aspect of the present disclosure is to ensure little or no variation in expected performance in terms of quantity of aerosol generated, and/or the quality of aerosol generated. In this regard, one aspect of the present disclosure is to ensure that the aerosol provision system is able to react to a state of an aerosol generation component of the aerosol provision system.

A further aspect of the example aerosol provision system is the functionality of providing different proportions of aerosol received / inhaled by the user. In this regard, the user may inhale an aerosol comprising different percentages of vapour generated from the aerosol generating components, e.g. cartomisers, located in the device. This may be based on the type of aerosol precursor material forming the aerosol generating components or within the aerosol generating components, for example when the aerosol generating components are cartomisers. The relative proportions may be altered by altering the airflow through each aerosol generating area within the device.

A further aspect of the example aerosol provision system is the ability to control how the aerosol precursor material is used-up (depleted) such that the aerosol precursor material stored within each of a plurality of aerosol generating components, e.g. cartomisers, is completely used-up (or depleted) at the same time in the future. This can ensure that the user does not use-up one of the aerosol generating components, e.g. cartridges, before the other, meaning that the user does not experience an undesired taste caused e.g., by the burning/heating of a dry wicking material resulting from an aerosol precursor material which has been completely (or almost) used up in one aerosol generating area and not another, and also that the user can replace both aerosol generating components, e.g. cartromisers, at the same time therefore minimising the user's interaction with the device <NUM> when replenishing the aerosol precursor materials. This can be realised by altering the power distributed to each of the atomising units designated for the respective aerosol generating areas (whether these form part of the aerosol generating component, or not). For example, when the aerosol generating component comprises a cartomiser having an atomising unit, this may include increasing the power supplied to the cartomiser having the smallest quantity of aerosol precursor and / or decreasing the power supplied to the cartomiser having the greatest quantity of aerosol precursor.

A further aspect of the example aerosol provision system is the ability to keep different aerosol pathways separate from one another and allow mixing of the different aerosols to occur in the user's mouth. For example, this may be in relation to different flavoured aerosols, where each cartomiser <NUM> contains its own source liquid producing a different flavour (e.g., strawberry flavour and raspberry flavour), and thus the different flavoured aerosols are kept separate / isolated from one another within the aerosol provision system <NUM> itself. This can provide a different sensorial experience to the user and may lead to less "blurring" of the flavours (in other words, the user may be able to identify the individual flavours more readily when each aerosol / vapour is provided directly to the mouth cavity compared to an aerosol mixed in the device). Moreover, the different aerosols may not experience substantial mixing even when leaving the device and effectively be deposited in different regions of the mouth (e.g., on a left and right side of mouth, or on the roof of the mouth and the tongue, etc.) meaning that it is the user themselves who performs the mixing. The device may further be configured to target the different aerosol to different parts of the mouth / mouth cavity, as different flavours may be more or less perceptible to certain areas of the mouth / mouth cavity.

By way of reference only, the following discussion will refer to top, bottom, left and right sides of the system. This will generally refer to the corresponding directions in the associated figures; that is, the natural directions in the plane of the figures. However, these directions are not meant to confer a particular orientation of the system <NUM> during normal use. For example, the top of the assembled system refers to a part of the system that contacts the user's mouth in use, while the bottom refers to the opposite end of the system. The choice of directions is only meant to illustrate the relative locations of the various features described herein.

Turning back to <FIG> and <FIG>, the control part <NUM> includes a housing <NUM> which is configured to house a power source <NUM> for providing operating power for the aerosol provision device <NUM> and control circuitry <NUM> for controlling and monitoring the operation of the aerosol delivery device <NUM>. In this example, the power source <NUM> comprises a battery that 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 outer housing <NUM> may be formed, for example, from a plastics or metallic material and in this example has a generally rectangular cross section with a width (in the plane of <FIG>) of around <NUM> to <NUM> times its thickness (perpendicular to the plane of <FIG>). For example, the electronic cigarette may have a width of around <NUM> and a thickness of around <NUM>. The control part <NUM> takes the form of a box / cuboid, in this example, although it should be appreciated that the control part <NUM> can have other shapes as desired.

The control part <NUM> further comprises an air inlet <NUM> provided on / in the outer surface of the housing <NUM>, two discrete aerosol generating areas, e.g. receptacles, 24a and 24b each defining a space / volume for receiving one of the aerosol generating components, e.g. cartomisers <NUM>, an air channel <NUM> which extends into the housing <NUM> and fluidly connects the air inlet <NUM> with the receptacles 24a and 24b, and two flow restriction members <NUM> provided within the air channel <NUM> at positions where each can vary the airflow into respective receptacles 24a, 24b (specifically in this example at or close to the entrance to the spaces defined by the receptacles 24a, 24b). As will be appreciated in the following these features form part of an air or aerosol pathway through the aerosol provision device <NUM> in which air is passed from outside the aerosol provision device <NUM> via air inlet <NUM>, through the aerosol generating areas / receptacles 24a and 24b containing cartomisers <NUM> and into the user's mouth. Turning now to the cartomisers, the cartomisers <NUM> each comprise a housing 40a, 40b, which defines a liquid reservoir 41a, 41b that stores a source liquid for vaporisation, and a cartomiser channel 44a, 44b, and an atomisation unit (or vaporiser) which in this example is formed of a wicking element 42a, 42b and a heating element 43a, 43b coiled around the wicking element 42a, 42b. The wicking elements 42a, 42b are configured to wick / transport a source liquid (using the capillary motion) from the respective liquid reservoirs 41a, 41b to the respective heating elements 43a, 43b.

In the example shown, the atomisation units are provided in the respective cartomiser channels 44a, 44b defined by the housing 40a, 40b of the cartomisers <NUM>. The cartomiser channels 44a and 44b are arranged such that, when the cartomisers <NUM> are installed in respective receptacles, the cartomiser channels 44a and 44b are fluidly communicated with the air channel <NUM> and air inlet <NUM>, and thus air drawn in through the air inlet <NUM> passes along the air channel <NUM> and along cartomiser channels 44a and 44b of the cartomisers <NUM>.

As used herein, the term "aerosol generating component" refers to a component that is responsible for generating aerosol. In <FIG> and <FIG>, this includes the cartomisers <NUM> which comprise both a source liquid (or aerosol forming material) and an atomisation unit. In this arrangement, the cartomisers <NUM> are considered the aerosol generating component because without the cartomisers <NUM> installed in the system (and / or cartomisers comprising source liquid), aerosol cannot be generated. Moreover, the term "aerosol generating area" refers to an area / region within the system in which aerosol is or can be generated. For instance, in <FIG> and <FIG>, the aerosol generating area includes receptacles 24a and 24b, which are configured to receive the cartomisers <NUM>. In other words, the cartomisers are considered as the components responsible for generating aerosol, whereas the receptacles house the aerosol generating components and thus define an area where aerosol is generated.

The mouthpiece part <NUM> includes a housing <NUM> which comprises two openings 31a, 31b at one end (a top end); that is, the mouthpiece openings are located at the same end of the mouthpiece part <NUM> and are generally arranged such that a user can place their mouth over both of the openings. The mouthpiece part <NUM> also includes receptacles 32a, 32b at the opposite end (a bottom end), and respective mouthpiece channels 33a, 33b extending between the receptacles 32a, 32b and the openings 31a, 31b.

The mouthpiece part <NUM> has a generally tapered or pyramidal outer profile which tapers towards the top end of the mouthpiece part <NUM>. The bottom end of the mouthpiece part <NUM> is where the mouthpiece part <NUM> and control unit <NUM> meet or interface and is sized to have dimensions in the width direction (i.e., in the horizontal direction of the plane of <FIG> and <FIG>) and thickness direction (i.e., in a direction orthogonal to the plane of <FIG> and <FIG>) that broadly correspond to equivalent dimensions of the control part <NUM> in order to provide a flush outer profile when the control part <NUM> and the mouthpiece part <NUM> are coupled together. The end of the mouthpiece part <NUM> in which the openings <NUM> are located (top end) is smaller in the width direction than the bottom end by around one third (e.g. to around <NUM> wide). That is, the mouthpiece part <NUM> tapers in the width direction towards the top end. This end forms the part of the aerosol provision device <NUM> that is received in the user's mouth (in other words, this is the end the user would normally put their lips around and inhale through).

The mouthpiece part <NUM> is formed as a separate and removable component from the control part <NUM> and is provided with any suitable coupling / mounting mechanism that allows the mouthpiece part <NUM> to couple to the control part <NUM>, e.g., snap-fitting, screw thread, etc. When the mouthpiece part <NUM> is coupled to the control part <NUM> to form the assembled aerosol provision device <NUM> (e.g., as generally shown in <FIG>), the length of the assembled aerosol provision device <NUM> is around <NUM>. However, it will be appreciated that the overall shape and scale of an aerosol provision device <NUM> implementing the present disclosure is not significant to the principles described herein.

The receptacles 32a, 32b are arranged to fluidly connect to the cartomiser channel 44a and 44b in the cartomisers <NUM> respectively (specifically at an end of the cartomiser opposite the end that connects to and is received in receptacles 24a, 24b). The receptacles 32a, 32b are fluidly connected to mouthpiece channels 33a and 33b which in turn are fluidly connected to openings 31a and 31b. Therefore, it should be appreciated that when the device <NUM> is fully assembled (e.g., as shown in <FIG>), the openings 31a and 31b of the mouthpiece part <NUM> are fluidly connected to air inlet <NUM> in the control part <NUM>.

Hence, the example aerosol provision device <NUM> generally provides two routes through which air / aerosol may pass through the device. For example, a first route starts from air inlet <NUM>, passes along air channel <NUM> and through flow restriction member 25a, then passes into the receptacle 24a and through the cartomiser channel 44a of the first cartomiser 4a, into the receptacle 32a, along the mouthpiece channel 33a of the mouthpiece part <NUM> to the opening 31a. Equally, a second route starts from air inlet <NUM>, passes along air channel <NUM> and through flow restriction member 25b, then passes into the receptacle 24b and through the cartomiser channel 44b of the second cartomiser 4b, into the receptacle 32b, along the mouthpiece channel 33b of the mouthpiece part <NUM> and to the opening 31b. In this example, each of the first and second routes share a common component upstream of the flow restriction members <NUM> (namely, air channel <NUM> which is coupled to air inlet <NUM>) but branch off from this common component. In the following, the cross-section of the routes is described as circular; however, it should be appreciated that the cross-section may be non-circular (e.g., any regular polygon) and also that the cross-section need not be a constant size or shape along the length of the two routes.

It should be appreciated by the foregoing that the example aerosol provision device <NUM> includes a number of components / parts that are duplicated and essentially provide separate and parallel air / aerosol flow paths through the device. Duplicated components are referenced by a number followed by a letter, e.g., 24a. Components indicated by the letter "a" are components that connect to, or define a first air / aerosol path, associated with a first cartomiser 4a, while components indicated by the letter "b" are components that connect to, or define a first air / aerosol path, associated with a second cartomiser 4b. Components having the same number will have the same functionality and construction as one another unless otherwise indicated. In general, the components will be collectively referred to in the following by their corresponding number, and unless otherwise indicated, the description applies to both components "a" and "b" referenced by that number.

In use, a user inhales on the mouthpiece part <NUM> of the example device <NUM> (and specifically through openings <NUM>) to cause air to pass from outside the housing <NUM> of the reusable part <NUM>, through the respective routes through the device along which the air / aerosol passes and ultimately into the user's mouth. The heating elements <NUM> are activated in order to vaporise the source liquid contained in the wicking elements <NUM> such that the air passing over / around the heating elements <NUM> collects or mixes with the vaporised source liquid to form the aerosol. Source liquid may pass into / along the wicking elements <NUM> from the liquid reservoir <NUM> through surface tension / capillary action.

Electrical power is supplied to the heating elements <NUM> from battery <NUM>, controlled / regulated by control circuitry <NUM>. The control circuitry <NUM> is configured to control the supply of electrical power from the battery <NUM> to the heating elements <NUM> in the respective cartomisers <NUM> so as to generate a vapour from the cartomisers <NUM> for inhalation by a user. Electrical power is supplied to the respective heating elements <NUM> via electrical contacts (not shown) established across the interface between the respective cartomisers <NUM> and the control part <NUM>, for example through sprung / pogo pin connectors, or any other configuration of electrical contacts which engage when the cartomisers <NUM> are received in / connected to the receptacles <NUM> of the control part <NUM>. Of course, respective heating elements <NUM> could be supplied with energy via other means, such as via induction heating, in which case electrical contacts that interfaces between the control part <NUM> / receptacles <NUM> and the cartomisers <NUM> are not required.

The control circuitry <NUM> is suitably configured / programmed to provide functionality in accordance with embodiments of the disclosure as described herein, as well as for providing conventional operating functions of the aerosol provision device <NUM> in line with the established techniques for controlling conventional e-cigarettes. Thus the control circuitry <NUM> may be considered to logically comprise a number of different functional blocks, for example a functional block for controlling the supply of power from the battery <NUM> to the heating element 43a in the first cartomiser 4a, a functional block for controlling the supply of power from the battery <NUM> to the heating element 43b in the second cartomiser 4b, a functional block for controlling operational aspects of the device <NUM> in response to user input (e.g., for initiating power supply), for example configuration settings, as well as other functional blocks associated with the normal operation of electronic cigarettes and functionality in accordance with the principles described herein. It will be appreciated the functionality of these logical blocks may be provided in various different ways, for example using a single suitably programmed general purpose computer, or suitably configured application-specific integrated circuit(s) / circuitry. As will be appreciated the aerosol provision device <NUM> will in general comprise various other elements associated with its operating functionality, for example a port for charging the battery <NUM>, such as a USB port, and these may be conventional and are not shown in the figures or discussed in detail in the interests of brevity.

Power may be supplied to the heating elements <NUM> on the basis of actuation of a button (or equivalent user actuation mechanism) provided on the surface of the housing <NUM> and which supplies power when the user presses the button. Alternatively, power may be supplied based on detection of a user inhalation, e.g., using an airflow sensor or pressure sensor, such as a diaphragm microphone, connected to and controlled by the control circuitry <NUM> which sends a signal to the control circuitry <NUM> when a change in pressure or airflow is detected. It should be understood that the principles of the mechanism for starting power delivery is not significant to the principles of the present disclosure.

As mentioned previously, an aspect of the present disclosure is an aerosol delivery device <NUM> configured to provide consistent aerosol delivery to the user regardless of the state / condition of the device <NUM>. In the example aerosol delivery device <NUM> shown in <FIG> and <FIG>, the cartomisers <NUM> are provided separately from the control part <NUM> and the mouthpiece part <NUM> and can therefore be inserted into or removed from the receptacles <NUM>. The cartomisers <NUM> may be replaced / removed for a variety of reasons. For example, the cartomisers <NUM> may be provided with different flavoured source liquids and the user can insert two cartomisers <NUM> of different flavours (e.g., strawberry flavoured and menthol / mint flavoured) into the respective receptacles <NUM> to create different flavoured aerosols, if desired. Alternatively, the cartomisers <NUM> can be removed / replaced in the event that a cartomiser <NUM> runs dry (that is, the source liquid in the liquid reservoir <NUM> is depleted).

Turning to the cartomisers <NUM> in more detail, the cartomisers <NUM> each comprise the housing <NUM>, which in this example is formed of a plastics material. The housing <NUM> is generally in the form of a hollow tubular cylinder having an outer diameter and an inner diameter, with the walls of the inner diameter defining the limits of the cartomiser channel <NUM>. The housing <NUM> supports other components of the cartomiser <NUM>, such as the atomiser unit mentioned above, and also provides a mechanical interface with the receptacles <NUM> of the control part <NUM> (described in more detail below). In this example the cartridge has a length of around <NUM> to <NUM>, an outer diameter of <NUM> to <NUM> and an inner diameter of around <NUM> to <NUM>. However, it will be appreciated the specific geometry, and more generally the overall shapes involved, may be different in different implementations.

As mentioned, the cartomiser <NUM> comprises a source liquid reservoir <NUM> which takes the form of a cavity between the outer and inner walls of the housing <NUM>. The source liquid reservoir <NUM> contains a source liquid. A source liquid for an electronic cigarette will typically comprise a base liquid formulation, which makes up the majority of the liquid, with additives for providing desired flavour / smell / nicotine delivery characteristics to the base liquid. For example, a typical base liquid may comprise a mixture of propylene glycol (PG) and vegetable glycerol (VG). The liquid reservoir <NUM> in this example comprises the majority of the interior volume of the cartomiser <NUM>. The reservoir <NUM> may be formed in accordance with conventional techniques, for example comprising a moulded plastics material.

The atomisation unit of each cartomiser <NUM> comprises heating elements <NUM> which in this example comprise an electrically resistive wire coiled around the respective wicking element <NUM>. In this example, the heating elements <NUM> comprise a nickel chrome alloy (Cr20Ni80) wire and the wicking elements <NUM> comprise a glass fibre bundle, but it will be appreciated that the specific atomiser configuration is not significant to the principles described herein.

The receptacles <NUM> formed in the control part <NUM> are approximately cylindrical and generally have a shape (inner surface) that conforms to the outer shape of the cartomisers <NUM>. As mentioned, the receptacles <NUM> are configured to receive at least a part of the cartomisers <NUM>. The depth of the receptacles (that is a dimension along the longitudinal axis of the receptacles <NUM>) is slightly less than the length of the cartomisers <NUM> (e.g., <NUM> to <NUM>) such that, when the cartomisers <NUM> are received in the receptacles <NUM>, the exposed ends of the cartomisers <NUM> slightly protrude from the surface of the housing <NUM>. The outer diameter of the cartomisers <NUM> is slightly smaller (e.g., about <NUM> or less) than the diameter of the receptacles <NUM> to allow the cartomisers <NUM> to slide into the receptacles with relative ease, but to fit reasonably well within the receptacles <NUM> to reduce or prevent movement in a direction orthogonal to the longitudinal axis of the cartomiser <NUM>. In this example the cartomisers <NUM> are mounted in a generally side-by-side configuration in the body of the control part <NUM>.

In order to insert, replace or remove the cartomisers <NUM>, the user will typically disassemble the device <NUM> (e.g., into a state generally as shown in <FIG>). The user will remove the mouthpiece part <NUM> from the control part <NUM> by pulling the mouthpiece part <NUM> in a direction away from the control part <NUM>, remove any previous cartomisers <NUM> located in the receptacles (if applicable) by pulling the cartomisers <NUM> in a direction away from the control part <NUM>, and insert a new cartomiser <NUM> in the receptacle <NUM>. With the cartomiser(s) <NUM> inserted in the receptacles <NUM>, the user then reassembles the device <NUM> by coupling the mouthpiece part <NUM> to the reusable part <NUM>. An assembled device <NUM> is schematically shown in <FIG>, although it should be noted that certain features are not shown to scale and exaggerated for the purposes of clarity, such as the gap between the mouthpiece part <NUM> and the housing <NUM> of the control part <NUM>, for example.

As described the control part <NUM> is provided with flow restriction members <NUM> located in respective flow paths for the separate cartomisers <NUM>. In this example, each flow path is provided with a single flow restriction member <NUM>, disposed at the upstream side of the receptacles <NUM>. The flow restriction members <NUM> in this example are mechanical one-way valves <NUM>, comprising a plurality of flaps formed of an elastomeric material; however, it will be appreciated that any suitable valve is considered within the scope of the present disclosure. The flaps of this example are biased to a closed position and, in this position, prevent or at least obstruct air passing from the airflow path <NUM> into the receptacles <NUM>. The elastomeric flaps may be fixed on one side to the outer wall of the flow paths (or to a suitable valve housing that is subsequently fixed to the outer wall of the flow paths) and are free to move at the other end. The elastomeric flaps are arranged to open in response to a force applied to the flaps in a certain direction (in this example, in a downward direction from the receptacles towards the valves).

<FIG> show an example of the valve operation according to the present example. Each of the cartomisers <NUM> is fitted with a mechanical engagement member arranged to mechanically engage with the respective valve <NUM>. In the example shown in <FIG>, the mechanical engagement member is a protrusion <NUM> (not shown in <FIG> and <FIG> for clarity) that extends beyond the circular base of the cartomiser <NUM>. The protrusion <NUM> in this example takes the shape of an annular ring or a hollow truncated cone which tapers in a direction away from the cartomiser <NUM>; that is, the tapered portion extends downwardly beyond the base of the housing <NUM>. The protrusion shown in <FIG> is attached to the inner wall of the cartomiser <NUM> using appropriate bonding techniques, e.g., adhesive, and also extends partway into the cartomiser channel <NUM> causing a narrowing of the cartomiser channel <NUM>. However, it should be appreciated that other shapes and arrangements of the mechanical engagement member are considered within the scope of the present disclosure. Generally, the shape of the protrusions <NUM> will be dependent upon the configuration / size of the valve <NUM>, receptacles <NUM>, and cartomiser <NUM>. The protrusion <NUM> may also be integrally formed with the housing <NUM> of cartomiser <NUM> as opposed to a separate component that is attached to the housing.

With reference to <FIG>, a user may push the cartomiser <NUM> into the receptacle <NUM>, e.g., by applying a force to the cartomiser <NUM> along the direction indicated by arrow X or by allowing the cartomiser <NUM> to drop into the receptacle <NUM> under the force of gravity. In <FIG> the cartomiser <NUM> is only partially inserted into the receptacle <NUM> and protrusion <NUM> is not in contact with the valve <NUM>. Accordingly, in this arrangement, the valve <NUM> is biased closed and no (or little) air can flow through valve <NUM>.

By applying additional force (or simply allowing the cartomiser to be completely received in the receptacle), the protrusion <NUM> contacts the valve <NUM> causing the valve <NUM> to open. More specifically, the tapered portions of the protrusion <NUM> cause the free ends of the elastomeric flaps to bend / angle downwards relative to their fixed position on the outer wall of the airflow paths <NUM>. This bending causes the free ends of the elastomeric flaps to separate from one another and form a gap through the valve <NUM>, through which air from the airflow path <NUM> may flow and into the cartomiser channel <NUM> of the cartomiser <NUM>. Should the user then remove the cartomiser <NUM> from the receptacle at a later time, the elastomeric flaps return to their biased, closed position as the protrusion <NUM> is moved away from the flaps of valve <NUM>.

In this example aerosol provision device <NUM>, the cartomisers <NUM> are freely inserted into the receptacles. To ensure that both the valve <NUM> is opened correctly / fully and that there is sufficient electrical contact between the electrical contacts (not shown) of the cartomiser <NUM> (which are electrically connected to the heating elements <NUM>) and receptacles <NUM> (which are electrically connected to power supply <NUM>), the exposed end of the cartomiser <NUM> can be contacted by receptacle <NUM> of the mouthpiece part <NUM> when the mouthpiece part <NUM> is coupled to the control part <NUM>. The receptacles <NUM> are formed in a similar manner to receptacles <NUM> in that they are cylindrical recesses within mouthpiece part <NUM> sized to receive a part of the cartomisers <NUM>. The distance between the bottom surface of the receptacle <NUM> and the top surface of receptacle <NUM> when the mouthpiece part <NUM> and control part <NUM> are coupled is set to be equal to or slightly less (e.g., <NUM>) than the length of the cartomisers <NUM>. In this way, when the user applies the mouthpiece part <NUM> after inserting the cartomiser(s) <NUM> into receptacle(s) <NUM>, the receptacle <NUM> contacts the exposed end of the cartomiser <NUM> and forces the cartomiser <NUM> to be seated properly in receptacle <NUM> as the user applies a force to the mouthpiece part <NUM>. When the mouthpiece part <NUM> is coupled to the control part <NUM>, the cartomiser <NUM> is restricted from moving in the longitudinal direction meaning that good electrical contact and good contact with the valve can be ensured. In other words, the cartomisers <NUM> are clamped in place within the receptacles <NUM> and <NUM> of the device <NUM> when the lid is coupled to the control part <NUM>. This configuration may also be applied when the cartomisers <NUM> are mechanically connected to the receptacles <NUM>, e.g., via a press-fit mechanism.

In addition, sealing can be provided between the cartomiser channel <NUM>, mouthpiece channel <NUM> and airflow path <NUM> meaning that leakage of the air / aerosol into other parts of the device <NUM> can be reduced. To help improve this sealing, a seal (such as an elastomeric O-ring or equivalent) can be placed so as to surround the entrances to cartomiser channel <NUM>, mouthpiece channel <NUM> and air channel <NUM>.

As should be appreciated from the above, when a cartomiser <NUM> is inserted into a respective receptacle <NUM>, the corresponding flow restriction member <NUM> is open which connects the respective first or second flow path to the common air channel <NUM>. Conversely, when a cartomiser <NUM> is not located in the respective receptacle <NUM>, the flow restriction member <NUM> is closed which isolates the first or second aerosol pathway from the common air channel <NUM>, essentially meaning that no air flows along this path. Accordingly, regardless of the state / configuration of the aerosol provision device <NUM> (e.g., in this example, whether both or only one of the cartomisers <NUM> are present) the user is provided with a more consistent experience / aerosol delivery.

Aerosol is defined as the suspension of solid or liquid particles in air or another gas, and as a result one can define a certain concentration of source liquid particles to air. The rate at which vaporisation occurs depends on many factors, such as the temperature of the heater (or power supplied to the heater), the airflow rate through the cartomiser <NUM>, the wicking rate of liquid wicking to the heater along wicking element <NUM>, etc. By way of illustration only, suppose for a given inhalation strength, the device of <FIG> (when both cartomisers 4a and 4b are inserted in the receptacles 24a and 24b) enables aerosol to be inhaled by the user having about <NUM>% of the aerosol composed of vaporised liquid particles. For the purposes of the example, it is assumed here that around half of the vaporised liquid particles (i.e., <NUM>%) is produced by each of the cartomisers 4a and 4b.

Now we consider two situations where only one cartomiser 4a is present in the device <NUM>. In one situation, cartomiser 4a is present and valve 25b (i.e., the valve associated with cartomiser 4b) is open. This allows air to flow both through cartomiser 4a and through receptacle 24b (which does not include cartomiser 4b). We assume for the sake of simplicity that this would mean <NUM>% of the air flows through cartomiser 4a and <NUM>% flows through receptacle 24b. Cartomiser 4a does not experience any change in the various conditions (e.g., air flow rate, wicking rate, etc.) as compared to the situation when both cartomisers 4a and 4b are present. Accordingly, the aerosol inhaled by the user is made up of only <NUM>% vaporised liquid particles. In other words, the concentration of liquid source particles in the inhaled air has decreased compared to the situation where both cartomisers 4a and 4b are present. This has an impact on the user's perception of the inhaled aerosol (e.g., the taste / flavour may not be as strong or noticeable).

The other situation is where cartomiser 4a is present but valve 25b (i.e., the valve associated with cartomiser 4b) is closed. This is in accordance with the teachings of the present disclosure. This situation allows air to flow through cartomiser 4a but not through receptacle 24b. We assume for the sake of simplicity that this would mean <NUM>% of the air flows through cartomiser 4a. In this situation, cartomiser 4a does experience a change in the various conditions associated with vaporisation. In this case, the airflow rate increases through cartomiser 4a which is likely to draw more liquid along the wicking element 42a and thus cause more vaporisation of the source liquid. It should be noted that an increased airflow rate also has an increased cooling effect on the heating element 43a, but in some implementations the heating elements <NUM> can be controlled to maintain the heating elements <NUM> at a certain temperature (e.g., by increasing the power supplied to the heating element <NUM>). Accordingly, the concentration of source liquid to air is increased in this scenario relative to the situation where valve 25b is open. In other words, the concentration of air to vaporised liquid particles in the situation where valve 25b is closed is closer to (and in some implementations be equal to) the concentration of air to vaporised liquid particles in the situation where two cartomisers 4a and 4b are present (e.g., this may result in aerosol inhaled by the user made up of between <NUM>% to <NUM>% vaporised liquid particles).

Accordingly, the user is presented with less of a discrepancy between the aerosol they receive regardless of whether one cartomiser or both cartomisers <NUM> are present in the device. In some cases, the flavour or mix of flavours will change (e.g., when using cartomisers containing different flavoured source liquids) but the user is provided with a generally consistent volume / quantity of vaporised liquid particles in either situation. This generally improves the user experience of the device and means that a user is able to use the device more flexibly (i.e., using one or two cartomisers) and receive a consistent experience.

In the above described implementation, the flow restriction members <NUM> are either controlled to be fully open when the cartomiser <NUM> is present in the receptacle <NUM>, or fully closed when the cartomiser <NUM> is not present in the receptacle <NUM>. However, in other implementations, the flow restriction members <NUM> are able to be actuated to varying positions between an open and closed position. That is, the flow restriction member <NUM> can be half open, one quarter open, etc. The extent to which the flow restriction member is open alters the resistance to draw of the device <NUM> (that is the resistance the user feels when sucking on the mouthpiece <NUM> of the device) - for example, a flow restriction member <NUM> that is half open has a greater resistance to draw on than a flow restriction member <NUM> that is fully open.

In other implementations, the flow restriction members <NUM> may be electrically operated valves, for example having an electric motor or the like which is driven in response to a signal to open the valve. That is, the control circuitry <NUM> in some implementations is arranged to actuate the electrically operated flow restriction members <NUM> in response to a certain input. The certain input in this implementation is not an input input by the user, but is instead an input that is dependent upon the current state / configuration of the aerosol provision device <NUM>. For example, when each cartomiser <NUM> is inserted into the receptacle <NUM>, an electrical connection is made between the electrical contacts (not shown) on the cartomisers <NUM> (that connect to the heating element <NUM>) and the electrical contacts in the receptacle (that connect to the control circuitry <NUM>). The control circuitry <NUM> in such implementations is configured to detect a change in the electrical properties when the cartomiser <NUM> is received in the receptacle (e.g., by detecting a change in resistance). This change in the electrical property is indicative of a cartomiser <NUM> being present in the receptacle <NUM> and upon detecting the change in electrical property, the control circuitry <NUM> is configured to transmit a signal to the electrically operated flow restriction member <NUM> (e.g., by supplying an electrical power from the battery <NUM> to a motor of the flow restriction members <NUM>) to cause the flow restriction member <NUM> to open. That is, the control circuitry <NUM> can be configured to detect the presence of the cartomisers <NUM> and is arrange to open the flow restriction member <NUM> if the cartomiser <NUM> is present within receptacle <NUM> or close the flow restriction members <NUM> if the cartomiser <NUM> is not present within the receptacle. It should also be appreciated that in the same way as the mechanical implementations described above, the electrically operated flow restriction members can be configured to be in an open, closed, or partially open state.

In other implementations, the consistency of aerosol delivery regardless of the state of the aerosol provision device <NUM> may not be the primary focus. Alternatively, the flow restriction members <NUM> may be used to control the relative proportions of aerosol generated by each of the two cartomisers <NUM>.

For instance, in an implementation in which mechanically actuated flow restriction members <NUM> are provided, the cartomisers <NUM> are provided with different shaped protrusions <NUM> which open or close the flow restriction members <NUM> to varying degrees. In this case, different source liquids may be provided in cartomisers having different shaped protrusions <NUM>. For example, although not shown, the tapered portion on protrusion <NUM> of cartomiser 4a may be shorter than that shown in <FIG> (and thus also have a greater taper angle), while the tapered portion of protrusion <NUM> of cartomiser 4b may be longer than that shown (and thus have a smaller taper angle). The shorter protrusion <NUM> of cartomiser 4a penetrates less deeply into the flow restriction member <NUM> meaning the flow restriction member <NUM> is only opened by a small amount (say, <NUM>% open). The longer protrusion of cartomiser 4b penetrates deeper into the flow restriction member <NUM> causing the flow restriction member <NUM> to open by a larger amount (say, <NUM>% open). In this situation, as the user inhales on the device, roughly <NUM>% of the air will pass through cartomiser 4a and <NUM>% of the air will pass through cartomiser 4b. This means the aerosol inhaled by the user will comprise a greater volume of liquid vapour generated by cartomiser 4b compared to the volume of the liquid vapour generated by cartomiser 4a. Assuming cartomiser 4a comprises a cherry flavoured source liquid and cartomiser 4b comprises a strawberry flavoured source liquid, the user will receive an aerosol comprising more strawberry flavour than cherry flavour, in this particular example.

It should also be appreciated that this form of control of the proportions of aerosol generated from each cartomiser <NUM> may also be applied to electrically operated flow restriction members <NUM>. For example, each cartomiser <NUM> may be provided with a computer readable chip that includes information about the source liquid contained in the cartomiser <NUM> (e.g., a flavour or strength of nicotine, for example). The control circuitry <NUM> can be provided with (or connected to) a mechanism for reading the chip of the cartomiser <NUM> to identify a property of the source liquid contained in the reservoir <NUM>. As a result, the control circuitry <NUM> actuates the flow restriction members <NUM> to open to a certain degree based on the type of source liquid and accordingly configures different proportions of the air / aerosol to be provided to the user. For instance, in line with the above example, the flow restriction member 25a may be set to be <NUM>% open while the flow restriction member 25b may be set to be <NUM>% open. Here it should also be noted that an electrical based system offers improved flexibility over the mechanical system in that the control circuitry <NUM> can set the proportions of the aerosol relative to the source liquids within the device - that is, the device could be set to provide an aerosol comprising more strawberry flavour than cherry flavour, or more cherry flavour to apple flavour, based on a look-up table or the like.

In addition to the above, the flow restriction members <NUM> may be actuated based on the amount of source liquid contained in the cartomisers <NUM>. For example, if cartomiser 4a contains a greater volume of source liquid in the liquid reservoir 41a than cartomiser 4b, the flow restriction member 25a may be opened by a greater amount than flow restriction member 25b. In this way, as a user inhales aerosol, the aerosol contains a greater proportion of vaporised source liquid from cartomiser 4a than from cartomiser 4b. This may be useful to help reduce the likelihood of one cartomiser (e.g., cartiomiser 4b) "drying out" (i.e., using up its source liquid) before the other cartomiser (e.g., cartomiser 4a). Providing this arrangement may ensure that the user does not experience an unpleasant taste when, for example, one of the cartomisers <NUM> dries out and starts heating a dry wicking element <NUM>.

In system in which electrically operated flow restriction members <NUM> are provided, the aerosol provision device <NUM> is provided with some mechanism for sensing/determining the quantity of aerosol contained in each of the cartomisers <NUM>. For example, the walls of the cartomiser housing <NUM> or the walls of the receptacles <NUM> may be provided with separate electrically conductive plates arranged to face one another such that the volume of source liquid in the cartomiser <NUM> is situated between the plates when the device <NUM> is in the assembled state. The plates are arranged to be electrically charged (e.g., via power supplied from battery <NUM> either continuously or intermittently) and the control circuitry <NUM> is configured to determine a capacitance measurement of the plates. As the volume of liquid located between the plates changes, the capacitance value changes and the control circuitry <NUM> is configured to identify this change and determine the quantity of liquid remaining. The above is just one example of how a quantity of source liquid in the reservoir <NUM> of the cartomisers <NUM> can be detected, but the principles of the present disclosure are not limited to this technique. Once the control circuitry <NUM> identifies the quantity of liquid remaining, the control circuitry <NUM> actuates the flow restriction members <NUM> as described above. This may include actuating the flow restriction members <NUM> to different positions between an open and closed position based on the quantity aerosol precursor material remaining in the two cartomisers <NUM> (or more generally in the aerosol generating areas) to vary the ratio of aerosols generated from the two cartomisers <NUM>. Additionally or alternatively, the flow restriction members <NUM> may be configured to remain open when a quantity of aerosol precursor is detected in the cartomiser (or more generally in the aerosol generating areas) and to close when the quantity falls below a certain limit (e.g., below <NUM>) or when it is detected that no aerosol precursor material remains.

In a system in which mechanically operated flow restriction members <NUM> are provided, the aerosol provision device <NUM> may include flow restriction members <NUM> that are activated in proportion to the weight of the cartomisers <NUM>. In other words, and with reference to <FIG>, a heavier cartomiser (i.e., one containing more source liquid) applies a greater downward force to the flow restriction member <NUM> than a lighter cartomiser (i.e., one containing less source liquid). This means the valves <NUM> open or close to a greater or lesser extent based on the weight of the cartomisers <NUM> and, accordingly, provide different proportions of aerosol from each of the cartomisers as the user inhales.

Hence it has been described above that the flow restriction members <NUM> are configured to vary the airflow through the respective cartomisers based on the presence of the cartomisers in the system and / or a parameter associated with the cartomisers in the system (e.g., a type of the source liquid or the quantity of source liquid in the cartomiser).

It should be appreciated that while the above techniques of controlling the flow restriction members <NUM> on the basis of a property of the cartomiser <NUM> have been described in isolation, it should be appreciated that in other implementations a combination of these techniques may equally be applied. For example, the percentage of airflow through cartomiser 4a may be set to be higher than the percentage of airflow through cartomiser 4b based on a type of liquid, but the percentages may also be weighted based on the quantity of liquid in the cartomisers <NUM>. For instance, suppose the split is <NUM>% to <NUM>% based on the liquid type, however the split might be controlled to be <NUM>% to <NUM>% based additionally on the liquid level.

It should also be appreciated that while the above describes implementations where the flow restriction members <NUM> are located at the entrances to the receptacles <NUM>, it should be appreciated that the flow restriction members <NUM> can be located at other positions along the separate flow paths within the device <NUM>. In other words, the flow restriction members <NUM> may be disposed at any position along the separate flow paths for air or aerosol through the device. For example, the flow restriction members may be located in receptacles <NUM> or mouthpiece channels <NUM> within the mouthpiece part <NUM> - that is, downstream of the atomisation units of the cartomisers <NUM>. However, the flow restriction members are not provided at locations that are common to the separate flow paths through the device. For instance, a flow restriction member <NUM> is not provided at the air inlet <NUM> of the device shown in <FIG> or <FIG>. In the described implementations, the flow restriction member <NUM> is provided at a location at which the flow of air through one respective cartomiser is altered. It should also be appreciated that multiple flow restriction members <NUM> may be provided for each flow path - for example, flow restriction members <NUM> may be placed before air enters the cartomiser channel <NUM> (e.g., in the entrance to receptacle <NUM> as shown in <FIG> and <FIG>) and also after aerosol exits cartomiser channel <NUM> (e.g., in the exit from receptacle <NUM> in mouthpiece channel <NUM>). This can provide the advantage of redundancy should one of the flow restriction members fail and / or permits the use of less robust or cheaper flow restriction members within the device <NUM>.

<FIG> schematically show, in cross-section, alternative arrangements of flow restriction members and control parts. <FIG> depicts a control part <NUM>' which is the same as control part <NUM>, with the exception that control part <NUM>' comprises two air inlets 23a' and 23b' and two air channels 26a' and 26b'. As can be seen from <FIG>, the air channels <NUM>' are separate from one another - that is, they are not fluidly connected within the control part <NUM>'. Each air channel <NUM>' connects to a receptacle <NUM> and to an air inlet <NUM>'. In essence, <FIG> depicts an implementation that is identical to the implementations described above with respect to <FIG> and <FIG> with the exception that there is no shared (or common) component of the flow paths through the device. That is, air channel 26a' connects air inlet 23a' to receptacle 24a only, and air channel 26b' connects air inlet 23b' to receptacle 24b only.

<FIG> depicts an example control unit <NUM>" which is the same as control unit <NUM> with the exception that there are multiple air inlets <NUM>" (specifically three) connected to a single receptacle <NUM> by an air channel <NUM>". <FIG> only depicts half the control unit <NUM>" (specifically the left-half with respect to <FIG> and <FIG>), although it should be appreciated there is a corresponding arrangement on the right-half of the control unit <NUM>". In the implementation of <FIG>, three flow restriction members <NUM>" are provided between each of the three air inlets <NUM>" in the control part <NUM>". In this implementation, each of the three air inlets <NUM>" can be controlled to be in an open or closed state. In this case, the resistance to draw can be changed depending on how many of the flow restriction members <NUM>" are open. For example, when all three flow restriction members <NUM>" are open, the resistance to draw is relatively low compared to the case when only one of the three flow restriction members <NUM>" are open. Accordingly, by altering the resistance to draw, the device <NUM> can alter the relative percentage of the total air inhaled that passes through each cartomiser <NUM>, in a similar manner to that described above. For example, if the flow restriction members <NUM>" that allow air to pass through cartomiser 4a are set to all be fully open, whereas the flow restriction members <NUM>" that allow air to pass through cartomiser 4b are set so that only one of the three are open, as the user inhales on the device, a greater proportion of the inhaled air passes through cartomiser 4a compared to cartomiser 4b as the flow path through cartomiser 4b has a greater resistance to draw.

In this arrangement shown in <FIG>, the flow restriction members <NUM>" may be electrically actuated or mechanically actuated, depending on the application at hand. That is, the flow restriction members <NUM>" may automatically open or close in response to a mechanical or electrical input. Moreover, in some implementations, the user may be provided with the option to manually control which of the flow restriction members <NUM>" are open or closed, depending on the user's preference.

As should be appreciated by the above, in use, airflow through the aerosol provision system can be controlled on the basis of a number of parameters. However, more generally, when using the device a first flow restriction member is adjusted in order to vary the flow of air along a first flow pathway arranged to pass through a first aerosol generating area and fluidly connected to the mouthpiece and a second flow restriction member is adjusted in order to vary the flow of air along a second flow pathway arranged to pass through a second aerosol generating area and fluidly connected to the mouthpiece. As described above, the flow restriction members vary the flow of air along respective pathways based on the presence of an aerosol generating component in the respective aerosol generating areas in the system and / or a parameter associated with the respective aerosol generating component in the system.

In addition, or as an alternative to controlling airflow through the device <NUM>, aspects of the present disclosure relate to the distribution of power between the cartomisers 4a and 4b in order to influence aerosol generation.

As mentioned, the control circuitry <NUM> is configured to control the supply of power to the heating elements <NUM> of the different cartomisers <NUM>; hence one function of the control circuitry <NUM> is power distribution. As used herein the term "power distribution circuitry" refers to the power distribution function / functionality of the control circuitry <NUM>.

In one implementation, power is distributed on the basis of the presence or absence of aerosol generating components, e.g. the cartomisers <NUM>, in the respective aerosol generating areas, e.g. receptacles <NUM>. In much the same way as described above, the control circuitry <NUM> can be configured to electrically detect whether a cartomiser <NUM> is installed in each of the receptacles <NUM> - for example, the control circuitry <NUM> may be configured to detect a change in electrical resistance as the cartomiser <NUM> is inserted into the receptacle <NUM> and an electrical connection is established between the heating wire <NUM> and the control circuitry <NUM> (e.g., through the coupling of electrical contacts on the cartomisers and the receptacles). The control circuitry <NUM> is therefore configured to identify how many cartomisers <NUM> are installed within the device at any one time, in this case by detecting a change in an electrical property (e.g. resistance) of the circuitry within the device <NUM>. As mentioned above, when the aerosol generating component is an aerosol precursor material, e.g. a liquid, capacitance is a suitable way of detecting whether an aerosol generating component is present in the aerosol generating area, although other detection mechanisms may be suitable, e.g., optical.

<FIG> is an exemplary schematic circuit diagram showing the electrical connections between battery <NUM> and the heating wires 43a and 43b of two cartomisers 4a and 4b installed in the device <NUM>. <FIG> shows heating wire 43a and heating wire 43b connected in parallel with the battery <NUM>. In addition, each arm of the parallel circuit is provided with a schematic representation of functional blocks of the control circuitry <NUM>, referred to here as control circuitry block 22a and / or 22b. It should be appreciated for simplicity that the functional blocks of control circuitry <NUM> are shown individually for ease of visualisation; however, the control circuitry <NUM> may be a single chip / electronic component configured to perform the described functionality, or each functional block may be implemented by a dedicated ship / circuit board (as generally described above). Control circuitry block 22a is a power control mechanism for controlling the power supplied to heating wire 43a, and control circuitry block 22b is a power control mechanism for controlling the power supplied to heating wire 43b. The power control mechanism may implement, for example, a pulse width modulation (PWM) control technique for supplying power to the respective heating wires <NUM>.

In <FIG>, two cartomisers <NUM> are installed in the device as identified by the presence of two heating wires <NUM> in <FIG>. The control circuitry <NUM> is configured to identify the presence of both cartomisers <NUM> in the device and subsequently supply power to both cartomisers <NUM>. Assuming the battery voltage is around <NUM> volts, each heating wire 43a maybe supplied with an (average) voltage around <NUM> volts. For the sake of simplicity, we assume here that each heating wire <NUM> is identical and, as a result, when power is supplied to each heating wire and vaporisation of the source liquid occurs, each cartomiser <NUM> produces the same quantity / volume of vapour.

<FIG> schematically represents the same circuitry as in <FIG>; however the second cartomiser 4b has been removed from the circuitry / device, meaning that heating wire 43b is no longer connected to the circuitry. In this case, and assuming circuitry 22a operates in the same way, heating wire 43a produces approximately the same quantity of vapour as in the case where cartomiser 4b is present as the power supplied to the heating wire is constant, however the total quantity of vapour produced by the device <NUM> as a whole is less because the contribution from cartomiser 4b is no longer present.

To compensate for this, circuitry 22a is configured to increase the voltage / power supplied to the heating wire 43a, e.g., by increasing the voltage supplied from <NUM> volts to <NUM> volts. For example, supposing the electrical resistance of the heating wires 43a and 43b are the same, when one cartomiser is removed from the circuit, the power P supplied to the remaining cartomiser can be doubled by supplying V2 times the voltage before. In simplistic terms, doubling the power supplied to a heating wire may cause approximately twice the volume of vapour to be produced.

That is, in the absence of one cartomiser in the device, the power supplied to the remaining cartomiser is increased in order to generate more vapour from the cartomiser that is present in the device. Accordingly, the heating wire 43a is capable of generating a greater quantity of vapour to compensate for the quantity of vapour that would otherwise be supplied from cartomiser 4b. In this case, the total quantity of vapour produced per inhalation can be controlled to be approximately the same (if not the same) regardless of whether the user installs one or two cartomisers <NUM> in the device <NUM>. In this way, the user is provided with a consistent volume of vapour whether one or two cartomisers are installed in the device, and therefore an overall more consistent experience when using the device <NUM>.

In practice, there are likely to be other effects (such as heat transfer efficiency to the liquid in the wicking material <NUM>, the rate of liquid wicking, etc.) that means the volume of aerosol might not be quite double when doubling the power. However, the device of the present disclosure can be calibrated such that the power supplied to the heating elements <NUM> is chosen such that twice the volume of vapour is generated from a single cartomiser <NUM> when only one cartomiser is present in the device.

It should also be appreciated that in some implementations the quantity of vapour inhaled may not necessarily be doubled to give a consistent user experience. For example, it may be determined that the user only requires around <NUM>% or <NUM>% or <NUM>% of the total volume of vapour generated with two cartomisers to be generated when one cartomiser is installed in the device. That is, the difference in the volume of aerosol produced in the situation where only one cartomiser is present in the device is less than or equal to <NUM>%, or <NUM>%, or <NUM>%. This may be down to the volume of air that can be inhaled through a single cartomiser <NUM> / flow path (i.e., due to an increase in resistance to draw).

In other implementations, it should be appreciated that control circuitry <NUM> may distribute power between the cartomisers <NUM> according to certain properties of the cartomiser, e.g., the liquid stored within the liquid reservoir <NUM> of the cartomisers. For instance, cartomiser 4a may contain a strawberry flavoured source liquid, while cartomiser 4b may comprise a cherry flavoured source liquid. When both cartomisers <NUM> are installed in the device <NUM>, the control circuitry 22a may distribute the power such that <NUM>% of the supplied power is directed to cartomiser 4a and <NUM>% of the supplied power is directed to cartomiser 4b. In such a situation, the inhaled aerosol comprises a larger proportion of cherry flavoured aerosol compared to strawberry flavoured aerosol. However, should cartomiser 4b be removed, the power distributed to cartomiser 4a is increased by more than double to provide the same quantity of vaporised liquid.

The circuitry blocks 22a and 22b are configured above to supply power to the heating wires <NUM> using a PWM technique. PWM is a technique that involves pulsing a voltage on / off for in predetermined times. One on / off cycle includes a duration of the voltage pulse and the time between subsequent voltage pulses. The ratio between the duration of a pulse to the time between pulses is known as the duty cycle. In order to increase (or decrease) the voltage (and hence power) supplied to the heating wires <NUM>, the circuity blocks 22a and 22b are configured to vary the duty cycle. For example, to increase the average voltage supplied to the first heating wire 43a, the duty cycle can be increased from <NUM>% (that is in one cycle, for half the cycle a voltage is supplied to the heating wire and for the other half a voltage is not supplied to the heating wire). The average voltage is a measure of the voltage supplied over the period of the duty cycle. In other words, each voltage pulse may have an amplitude equal to the battery voltage, e.g., <NUM> V, but the average voltage supplied to the heating wire <NUM> is equal to the battery voltage supplied multiplied by the duty cycle.

<FIG> are graphs showing example PWM power distributions. Along the x-axis is indicated time and along the y-axis is indicated voltage (i.e., the voltage value of the various voltage pulses). In <FIG>, pulses labelled "A" indicate a voltage supplied to heating wire 43a, while pulses labelled "B" indicate a voltage supplied to heating wire 43b.

<FIG> shows a first example power distribution in which an equal average voltage is supplied to each of the heating wires <NUM>. As mentioned, a cycle is the total time from the start of a pulse to the start of the next pulse, and in this example, for both heating wires 43a and 43b, half of the total time is spent supplying a voltage pulse to the heating wire - hence, the duty cycle for each heating wire is <NUM>%. In <FIG>, the duty cycle for pulse A is reduced to around <NUM>%, meaning that a larger average voltage is supplied to heating wire 43b relative to heating wire 43a resulting a greater volume of source liquid being vaporised from cartomiser 4b.

It should also be appreciated from <FIG> that the voltage pulses are alternately applied to heating wires 43a and 43b - that is, the voltage pulses supplied to heating wire 43a are not in phase. This can lead to a simpler control mechanism being implemented in control circuitry <NUM>. For example, a single switch configured to switch between a "connected to heating wire 43a" state, a "connected to heating wire 43b" state, and a "not connected" state can be implemented in control circuitry <NUM> to realise the three possible connection states. In <FIG>, the switch can be controlled to alternate between the two connection states, while in <FIG> the switch can be controlled to also pass through the not connected state (i.e., in order to realise the gap between pulses A and B in <FIG>). In this way the control circuitry and method of controlling the circuitry can be simplified. However, it should be appreciated in other implementations that different control mechanisms may be used, e.g., each heating wire <NUM> can be controlled by a separate switch.

It should also be appreciated that although it is shown in <FIG> that each heating wire is alternatively supplied with a voltage pulse, the period of one cycle may be a few tens of ms, meaning that in practice each cartomiser 4a and 4b generates vapour at approximately the same time and thus both generated vapours are delivered to the user and substantially the same time.

As mentioned above, it should also be appreciated that the total power supplied to the heating elements <NUM> may be dependent upon the strength of a user inhalation. That is, if a user inhales more strongly, a greater voltage may be supplied to the heating elements <NUM> to generate a greater quantity of vapour / aerosol. In these implementations, it should be appreciated that the duty cycle will be a function of inhalation strength. That is, taking the pattern in <FIG> as an example, the duty cycle may vary for both heating wires <NUM> between say <NUM>% to <NUM>%, where <NUM>% is selected for the strongest possible inhalation (or at least an inhalation above a maximum threshold value) and <NUM>% is selected for the weakest possible inhalation (or at least an inhalation strength equal to a threshold for detecting an inhalation). This may be applicable either when the duty cycles for both heating wires <NUM> are the same, or when the duty cycles are different (e.g., as in <FIG>), in which case the duty cycles may be varied to provide a certain ratio in the duty cycles between heating wire 43a and heating wire 43b.

It should also be appreciated that the total power supplied to the heating elements <NUM> may be dependent on a user input. For example, the device <NUM> may include a volume selection mechanism, which may be a button or switch (not shown) located on the reusable part <NUM> and which allows the user to select the quantity of aerosol produced. For instance, the volume selection mechanism may be a three position switch that can be actuated between a low, medium, or high setting where the low setting provides less aerosol to the user than the high setting and the medium setting provides a volume of aerosol somewhere between the volumes provided by the low and high settings. This may be the case when the power is supplied to the heating elements <NUM> via a user actuated button which, when pressed, supplies power to the heating elements <NUM>. In this case, the volume selection mechanism controls the total power supplied to the heating elements <NUM> when the user actuates the power supply button. In a similar way as described above, the duty cycles are varied depending upon the setting of the volume selection mechanism.

In another aspect of the present disclosure, power may be distributed between the cartomisers <NUM> to reduce the chance of dry-out. As described above, drying-out should be avoided in order to maintain a consistent user experience when using the device <NUM>. One way this can be controlled is via controlling the aerosol flow through each of the cartomisers <NUM>; however one can alternatively (or additionally) control the power supplied to each of the cartomisers <NUM>.

For example, in one implementation, the control circuitry <NUM> is configured to determine the quantity of source liquid stored in each of the liquid reservoirs <NUM>, as described above in relation to the flow restriction members <NUM> (e.g., via capacitive plates detecting a change in capacitance as the source liquid is used up).

The control circuitry <NUM> is then configured to determine the power to be supplied to the respective cartomisers <NUM> based on the detected source liquid level (that is, the control circuitry <NUM> receives a signal or signals indicative of the sensed liquid level). In essence, the control circuitry <NUM> is configured to supply power such that the liquid reservoirs <NUM> will fully deplete at the same point in time in the future by adjusting the rate at which the source liquid is being used (or more accurately vaporised) by the device <NUM>. For example, suppose cartomiser 4a contains <NUM> of source liquid while cartomiser 4b contains <NUM> of liquid. In this case, the source liquid in cartomiser 4b should be vaporised (consumed / depleted) at half the rate of the source liquid in cartomiser 4a in order for the cartomisers to be fully deplete at the same time in the future. The term "same time in the future" here should be understood to mean a point in time, either exactly or within a certain tolerance. For example, this may be based on a range within time, e.g., within <NUM> second or within <NUM> minute, etc., or within a certain number of puffs, e.g., within <NUM> puff or <NUM> puffs, etc. Equally, "fully depleted" should be understood to mean where no aerosol precursor remains or a small amount of aerosol precursor remains, e.g., less than <NUM>%, <NUM>%, or <NUM>% of the maximum volume of aerosol forming material that can be stored in the cartomiser <NUM>.

This rate is dependent (at least in part) on the power supplied to the heating elements <NUM>. Accordingly, the control circuitry <NUM> is configured to calculate a power to be supplied to the respective cartomisers <NUM> such that the rate at which the cartomisers vaporise the source liquid means the remaining liquid will be consumed at the same point in time in the future. This means that the likelihood of the user experiencing a foul taste resulting from one of the cartomisers heating / burning a dry wicking element <NUM> while the other cartomiser continues to produce aerosol is reduced.

Generally speaking, the control circuitry <NUM> will supply a greater proportion of the power to the heating element <NUM> of the cartomiser <NUM> that comprises the greatest quantity of source liquid; that is, a greater power / average voltage will be supplied to cartomiser 4a. For example, if approximately <NUM> Watts is supplied to cartomiser 4b, then <NUM> Watts will be supplied to cartomiser 4a.

In one implementation, the control circuitry <NUM> is configured to continually determine the quantities of liquid within the cartomisers during use of the device <NUM>. For example, the control circuitry <NUM> may receive a continuous measurement of the source liquid levels in the cartomisers (e.g., from the capacitive sensor) or the control circuitry may periodically receive a signal from the sensor. Based on the received signal, the control circuitry may increase or decrease the power supplied to the cartomisers accordingly. The control circuitry is configured to decrease the power supplied to the atomisation unit of the cartomiser that comprises the smallest quantity of source liquid and / or increase the power supplied to the atomisation unit of the cartomiser that comprises the greatest quantity of source liquid relative to the power supplied prior to the update. The control unit may proportion the power based on a certain total power (which may affect the volume of aerosol produced). For instance, using the above example, a total of <NUM> Watts is supplied to both cartomisers to generate a certain quantity of vapour, and during use the control circuitry <NUM> may determine that cartomiser 4b is not using the liquid quickly enough (and so cartomiser 4a will dry out more quickly). The control circuitry <NUM> is configured to alter the power supplied to cartomiser 4b from 3W to 4W, for example, and subsequently decrease the power supplied to cartomiser 4a from 6W to 5W. It should be appreciated that there may be no requirement to maintain a continuous total power, however, and so the control circuitry may instead increase / decrease the power to one or the other of the cartomisers.

It should be appreciated that while the above has described the reduction of the chance of one cartomiser drying-out before the other using power distribution, the skilled person will appreciate that this can also be achieved via additionally controlling air flow through the cartoimsers (as described above). In this regard, the control circuitry <NUM> is configured to take into account the degree at which the flow restriction members <NUM> are open (and so the airflow rate through each of the cartomisers) before setting the proportion of power to be distributed to the different atomisation units. This can offer an increased level of flexibility when preventing one cartomiser drying out before the other and may also offer a reduced impact on the users taste / experience of the aerosol (e.g., by altering the relative concentrations of the aerosols).

Another aspect of the present disclosure is the provision of two separate aerosol pathways, which are defined here as pathways that transport generated aerosol from the aerosol generating components, such as cartomiers <NUM>, in the aerosol generating areas.

As mentioned previously, the example aerosol provision device <NUM> of <FIG> and <FIG> generally provides two routes through which air / aerosol may pass through the device. For example, a first route starts from air inlet <NUM>, passes along air channel <NUM> and through flow restriction member 25a, then passes into the receptacle 24a and through the cartomiser channel 44a of the first cartomiser 4a, into the receptacle 32a, along the mouthpiece channel 33a of the mouthpiece part <NUM> to the opening 31a. A second route starts from air inlet <NUM>, passes along air channel <NUM> and through flow restriction member 25b, then passes into the receptacle 24b and through the cartomiser channel 44b of the second cartomiser 4b, into the receptacle 32b, along the mouthpiece channel 33b of the mouthpiece part <NUM> and to the opening 31b.

Each of the first and second routes through the device share a common component upstream of the flow restriction members <NUM> (namely, air channel <NUM> which is coupled to air inlet <NUM>) but branch off from this common component. An aerosol pathway is defined in the present disclosure as a pathway starting from the component responsible for generating the aerosol / vapour. In the present example device <NUM>, these are heating wires 43a and 43b of the cartomisers <NUM>. It should be appreciated that these are the components along the first and second routes that first generate vapour from vaporising the source liquid and, as such, any air flowing downstream of this point along the first and second routes is a combination / mixture of air and the generated vapour - that is, an aerosol. Accordingly, a first aerosol pathway and a second aerosol pathway can be defined within the device <NUM>. That is, the first aerosol pathway first aerosol pathway starts from heating element 43a, passes through cartomiser channel 44a of the first cartomiser 4a, into the receptacle 32a and along the mouthpiece channel 33a of the mouthpiece part <NUM> to the opening 31a. The second aerosol pathway starts from heating element 43b passes through the cartomiser channel 44b of the second cartomiser 4b, into the receptacle 32b and along the mouthpiece channel 33b of the mouthpiece part <NUM> to the opening 31b.

As should be appreciated from <FIG> and <FIG>, the first and second aerosol pathways are physically isolated from one another downstream of the atomisation unit. More specifically, aerosol generated from passing by heating element 43a and aerosol generated from passing by heating element 43b are not permitted to mix within the device during normal use. Instead, the individual aerosols exit the device <NUM> through the respective mouthpiece openings 31a and 31b and initially are separate from one another immediately after exiting the device <NUM>. The fact that the aerosols are physically isolated from one another when passing through the device <NUM> can lead to different user experiences when receiving the separate aerosol as compared to inhaling aerosols that are mixed within the device. The term "in normal use" should be understood to mean "as a user inhales normally on the device" and thus, specifically, we refer here to the normal route through the device that the aerosol would take when a user inhales in this way. This should be distinguished from abusive behaviour, e.g., exhaling into the device rather than inhaling (for example). In normal use, the present disclosure describes arrangements in which the different aerosols are isolated downstream of the point at which the aerosol is generated.

Aerosols exiting the device can be mixed to provide a combination of the aerosols to the user predominately via two methods. The first method involves the different aerosols exiting the device <NUM> separately from one another and, as the user further inhales and draws the aerosols into the user's oral cavity, the two aerosols may mix in the user's oral cavity before impacting on a surface of the oral cavity (e.g., the tongue or inner surface of the cheeks) where the mixture of aerosols is then received by the user. It should also be pointed out that mixing may occur at other points after the oral cavity along the user's respiratory organs, e.g., in the throat, oesophagus, lungs etc. The second method involves keeping the aerosols substantially separate such that each aerosol predominately impacts a different area of the user's mouth (e.g., such as the left and right inner surfaces of the cheeks). Here the mixing is performed by the user's brain combining the different signals resulting from receiving the aerosols in different parts of the mouth. Generally, both of these techniques here are referred to as "mixing in the mouth" as opposed to mixing in the device. It should be appreciated that in practice the different aerosols that are inhaled will likely mix via both of the two methods; however, depending on the configuration of the mouthpiece part <NUM>, the mixing may occur predominately via one of the methods described above.

The mouthpiece part <NUM> shown in <FIG> and <FIG> provides the mouthpiece channels <NUM> in such that the axes of the channels <NUM> converge at a point away from the top end of the device <NUM>. In other words, assuming the mouthpiece part defines an axis that extends from the bottom end to the top end of the device and passes generally through the centre of the mouthpiece part, the aerosols are configured to be directed toward the axis. Generally, this mouthpiece part <NUM> may be considered to mix aerosols predominately according to the first method described above, namely via mixing of the aerosols before the impacting a surface of the user's mouth.

<FIG> schematically shows another exemplary mouthpiece part <NUM> configured to fit / couple to control part <NUM>. <FIG> shows the mouthpiece part <NUM> in cross-section on the left hand-side and on the right hand-side of <FIG> is shown the mouthpiece part <NUM> as viewed in a direction along a longitudinal axis of the mouthpiece part <NUM>. Mouthpiece part <NUM> is substantially the same as mouthpiece part <NUM> with the exception that ends of the mouthpiece channels 133a and 133b are provided such that they divert away from the general longitudinal axes of the mouthpiece channels <NUM>. Accordingly, the mouthpiece openings 131a and 131b are provided at positions closer to the left and right sides of the mouthpiece part <NUM> as compared to openings 31a and 31b of mouthpiece part <NUM>. The longitudinal axes of the end parts of the mouthpiece channels <NUM> converge at a point within the device <NUM> (in contrast to mouthpiece part <NUM>). That is, the channels <NUM> are configured to divert the separate aerosols away from the longitudinal axis of the mouthpiece part <NUM>.

Generally, this mouthpiece part <NUM> may be considered to mix aerosols predominately according to the second method described above, namely via mixing of the aerosols after each separate aerosol impacts a surface of the user's mouth. In other words, mouthpiece part <NUM> can be considered to direct or target the different aerosols to different parts of the user's mouth.

<FIG> schematically shows another exemplary mouthpiece part <NUM> configured to fit / couple to control part <NUM>. <FIG> shows the mouthpiece part <NUM> in cross-section on the left hand-side and on the right hand-side of <FIG> is shown the mouthpiece part <NUM> as viewed in a direction along the longitudinal axis of the mouthpiece part <NUM>. Mouthpiece part <NUM> is substantially the same as mouthpiece part <NUM> with the exception that the mouthpiece channels 233a and 233b are provided at a shallower angle relative to the longitudinal axis of the device <NUM>. That is longitudinal axes of mouthpiece channels <NUM> converge at a point further way from the device <NUM> as compared to mouthpiece part <NUM>. The mouthpiece openings 231a and 231b are subsequently separated by a greater distance, indicated as separation distance y in <FIG>. Note also that the width of the top end of the mouthpiece part <NUM> is greater than the width of the top end of mouthpiece part <NUM>, e.g., the width of mouthpiece part <NUM> is around <NUM>. This arrangement means that the degree of mixing of the aerosols is less than with mouthpiece part <NUM>. Additionally, by providing a suitable separation distance y between the mouthpiece openings <NUM> of, for example, between <NUM> to <NUM>, e.g. <NUM>, the user is able to selectively inhale from mouthpiece opening 231a, mouthpiece opening 231b or a combination of mouthpiece openings 231a and 231b by positioning their mouth over the corresponding mouthpiece opening(s) <NUM>. That is, the user can choose which of the aerosols they receive (and hence which of the heating wires 43a, 43b of the cartomisers <NUM> are supplied with power). More generally, the mouthpiece openings <NUM> are provided at positions on the mouthpiece part <NUM> which allow the user to selectively inhale from the mouthpiece openings <NUM>.

<FIG> schematically shows another exemplary mouthpiece part <NUM> configured to fit / couple to control part <NUM>. <FIG> shows the mouthpiece part <NUM> in cross-section on the left hand-side and on the right hand-side of <FIG> is shown the mouthpiece part <NUM> as viewed in a direction along the longitudinal axis of the mouthpiece part <NUM>. Mouthpiece part <NUM> is substantially the same as mouthpiece part <NUM> with the exception that the mouthpiece channels 333a and 333b are configured to provide different sized, and in this case also concentric, mouthpiece openings 331a and 331b. More specifically, it can be seen that mouthpiece opening 331a surrounds the outer diameter of mouthpiece opening 331b. In this regard it should be appreciated that mouthpiece channel 333b includes a walled section which extends into the hollow portion of mouthpiece channel 333a (e.g., mouthpiece channel 333b includes a vertically extending tubular wall which partitions channel 333a from 333b).

This configuration provides the second aerosol surrounded by the first aerosol as the aerosols exit the mouthpiece part <NUM>. The majority of the mixing may be performed via the first method above, however this configuration may also lead to situations where the first aerosol (that is, the aerosol generated from cartomiser 4a) impacts the user's mouth shortly before the second aerosol (that is, the aerosol generated from cartomiser 4b). This can lead to a different user experience, e.g., a gradual reception / transition from the first to the second aerosol.

<FIG> schematically shows another exemplary mouthpiece part <NUM> configured to fit / couple to control part <NUM>. <FIG> shows the mouthpiece part <NUM> in cross-section on the left hand-side of the Figure and on the right hand-side of <FIG> is shown the mouthpiece part <NUM> as viewed in a direction along the longitudinal axis of the mouthpiece part <NUM>. Mouthpiece part <NUM> is substantially the same as mouthpiece part <NUM> with the exception that the mouthpiece channel 433b is split into two channels coupling to two mouthpiece openings 431b. Specifically, the mouthpiece openings are arranged such that openings 431b fluidly connected to cartomiser 4b are provided either side of the mouthpiece opening 431a fluidly connected to cartomiser 4a. It should be noted that one branch of mouthpiece channel 433b is shaped to pass overtop (or underneath) the mouthpiece channel 433a This can provide a different user experience by directed the aerosol generated from cartomiser 4b towards the outer portions of the user's mouth while directing the aerosol generated form cartomiser 4a towards the middle of the oral cavity.

In general, in view of <FIG> and the mouthpiece part <NUM> of <FIG> and <FIG>, it can be seen that the mouthpiece part of the aerosol provision device <NUM> can be arranged in a variety of ways to achieve mixing of the different aerosols within the mouth of a user of the device <NUM> to provide the user with different user experiences. In each of the examples shown, the aerosols are prevented from mixing within the device, in normal use. While the above mentioned Figures show specific designs of the mouthpiece parts, it should be appreciated that the mouthpiece channels may take any configuration necessary or desired in order to realise the intended functions of either mixing aerosols within the oral cavity or targeting aerosols to certain regions of the oral cavity.

<FIG> schematically show alternative arrangements of mouthpiece parts <NUM> and <NUM>. In these figures, the mouthpiece parts are provided with modified ends of the various mouthpiece channels in order to provide the aerosol streams with different properties, specifically different densities.

<FIG> schematically shows an exemplary mouthpiece part <NUM> configured to fit / couple to control part <NUM>. <FIG> shows the mouthpiece part <NUM> in cross-section on the left hand-side and on the right hand-side of <FIG> is shown the mouthpiece part <NUM> as viewed in a direction along the longitudinal axis of the mouthpiece part <NUM>. Mouthpiece part <NUM> is substantially the same as mouthpiece part <NUM>. However, mouthpiece channels 533a and 533b are provided with end sections <NUM> that provide a widening or narrowing of the mouthpiece channel <NUM> towards the top end of the mouthpiece part <NUM>.

More specifically, mouthpiece channel 533a includes an end section 534a in which the diameter of the mouthpiece channel 533a gradually increases in the downstream direction. This results in a relatively large diameter mouthpiece opening 531a. As aerosol generated from cartomiser 4a is inhaled along mouthpiece channel 533a by the user's puffing action, the density of the aerosol gradually decreases as the aerosol moves through end section 534a. This leads to aerosol expelled from the mouthpiece opening 531a that is relatively diffuse compared to aerosol expelled from mouthpiece opening 31a, for example. Generally speaking, a mouthpiece channel including an end section which increases in diameter (or width / thickness) towards the point where aerosol exits the device <NUM> provides a more diffuse aerosol stream.

Conversely, mouthpiece channel 533b includes an end section 534b in which the diameter of the mouthpiece channel 533b gradually decreases in the downstream direction. This results in a relatively small diameter mouthpiece opening 531b. As aerosol generated from cartomiser 4b is inhaled along mouthpiece channel 533b by the user's puffing action, the density of the aerosol gradually increases as the aerosol moves through end section 534b. This leads to a more concentrated jet of aerosol being expelled from the mouthpiece opening 531b compared to aerosol expelled from mouthpiece opening 31b, for example. Generally speaking, a mouthpiece channel including an end section which decreases in diameter (or width / thickness) towards the point where aerosol exits the device <NUM> provides a more jet-like concentrated aerosol stream (or a less diffuse aerosol stream).

It should be appreciated that although <FIG> shows the end sections <NUM> of each mouthpiece channel <NUM> located below the top end of the mouthpiece part (that is, below the uppermost surface), the mouthpiece channels and hence the end section may extend beyond the top end of the mouthpiece part. For example, <FIG> schematically shows a modified version of mouthpiece part <NUM> shown in <FIG>. <FIG> shows the mouthpiece part <NUM> in cross-section on the left hand-side and on the right hand-side is shown the mouthpiece part <NUM> as viewed in a direction along the longitudinal axis of the mouthpiece part <NUM>. In this arrangement, mouthpiece channel 333b is additionally provided with end portion 634b that extends / protrudes from the end of mouthpiece channel 333b. The end section 634b may be a separate component fitted to the end of mouthpiece channel 333b, or end section 634b may be integrally formed with the mouthpiece channel 333b (in essence providing an extension to mouthpiece channel 333b). End section 634b is provided with walls that narrow in diameter in a downstream direction, and so aerosol expelled from the end section is more jet-like (i.e., it has a higher source liquid particle density).

The above examples show how end sections of the mouthpiece channel may be formed in order to give different properties to the aerosol that is expelled from that mouthpiece channel. However, it should be appreciated that the entire mouthpiece channel, as opposed to merely an end section, can be formed to give different properties to the aerosol. For example, the channel 533b in <FIG> could alternatively be configured to gradually decrease in diameter from the connection to receptacle 32b through to opening 531b in order to a provide a jet-like aerosol stream. It should also be appreciated that in other embodiments the mouthpiece channels may be provided with additional components (e.g., a baffle plate) to adjust the properties of the aerosol exiting the channel.

It should also be appreciated that while the above examples have generally focused on providing different aerosol streams that mix in the mouth of a user and, in some cases, that are targeted to different regions of the mouth, in some implementations the different aerosol streams may be targeted to completely different regions of the user's respiratory system. For example, aerosol generated by cartomiser 4a may be targeted to deposit in the oral cavity of the user's mouth (which may be achieved using a mouthpiece channel shaped such as channel 533a to provide a diffuse cloud-like aerosol within the oral cavity), whereas aerosol generated from cartomiser 4b may be targeted to deposit in the lungs of the user's respiratory system (which may be achieved using a mouthpiece channel shaped such as channel 533b to provide a jet-like stream of aerosol which travels generally deeper into the respiratory system with relatively less dispersion). Such an arrangement could be used to deliver a flavoured aerosol to the user's mouth and a nicotine containing aerosol to the user's lungs, for example. Alternatively and/or additionally, the system could be configured to produce multiple aerosols with differing particle size distributions.

The term aerosol generating component has generally been exemplified throughout by a cartomiser <NUM>, where the cartomiser includes both a source liquid (or more generally an aerosol precursor material) and an atomising unit. More generally the term aerosol generating component refers to components that allow for the generation of aerosol when present in the device <NUM>.

For example, it has been described above that the control part <NUM> receives a plurality of cartomisers <NUM>, where the cartomisers <NUM> include the liquid reservoir <NUM> and an atomisation unit, which is described above as including a wicking element <NUM> and a heating element <NUM>. In this regard, a cartomiser is considered herein to be a cartridge that includes an atomisation unit. It should be appreciated that in some implementations, the atomisation unit is alternatively provided in the control part <NUM> of the aerosol provision device <NUM>. In this case, instead of cartomisers being inserted into the receptacles <NUM> of the device <NUM>, cartridges (which do not include an atomisation unit) can be inserted into the receptacles of the device. The cartridges can be configured to mate with the atomisation unit in a suitable way depending on the type of atomisation unit installed. For example, if the atomisation unit comprises a wicking element and a heating element, the wicking element can be configured to fluidly communicate with the source liquid contained in the cartridge. Hence, in implementations where the control part <NUM> is arranged to receive a cartridge, the cartridge is considered to be the aerosol generating component.

It has also been described above that cartomisers / cartridges include a liquid reservoir containing a source liquid which acts as a vapour / aerosol precursor. However, in other implementations, the cartomisers / cartridges may contain other forms of vapour / aerosol precursor, such as tobacco leaves, ground tobacco, reconstituted tobacco, gels, etc. It should also be understood that any combination of cartridges / cartomisers and aerosol precursor materials can be implemented in the above described aerosol provision system. For example, cartomiser 4a may include a liquid reservoir <NUM> and source liquid, while cartomiser 4b may include reconstituted tobacco and a tubular heating element in contact with the reconstituted tobacco. It should be appreciated that any suitable type of heating element (or more generally atomising unit) may be selected in accordance with aspects of the present disclosure, e.g., a wick and coil, an oven-type heater, an LED type heater, a vibrator, etc..

It has also been described that the aerosol provision device <NUM> is capable of receiving aerosol generating components, e.g., two cartomisers <NUM>. However, it should be appreciated that the principles of the present disclosure can be applied to a system configured to receive more than two aerosol generating components, e.g., three, four, etc. cartomisers.

In other implementations in accordance with certain aspects of this disclosure, the aerosol generating areas, i.e., receptacles <NUM>, are instead configured to receive a quantity of aerosol precursor material directly, e.g., a quantity of source liquid. That is, the aerosol generating areas are configured to receive and / or hold the aerosol precursor material. As such, the aerosol generating component is considered to be the aerosol precursor material. In these implementations, the atomisation unit is provided in the control part <NUM> such that it is able to communicate with the aerosol precursor material in the receptacle <NUM>. For example, the aerosol generating areas, e.g. receptacles <NUM>, may be configured to act as liquid reservoirs <NUM> and be configured to receive a source liquid (the aerosol generating component). An atomising unit, including a wicking material and a heating element, is provided in or adjacent the receptacle <NUM> and thus liquid can be transported to the heating element and vaporised in a similar manner to that described above. In these implementations, however, the user is able to re-fill (or re-stock) the receptacles with the corresponding aerosol precursor material. It should also be appreciated that the receptacles may receive a wadding or similar material soaked in a source liquid, with the wadding being placed in contact with / proximal to an atomising unit.

It has also been described above that the mouthpiece part <NUM> is a separate component to the control part <NUM>. In some cases, a plurality of mouthpiece parts <NUM> having different shaped mouthpiece channels <NUM> may be supplied to the user; for example, the user may be supplied with mouthpiece parts <NUM>, <NUM>, <NUM>, etc. The user is able to swap which mouthpiece parts <NUM>, <NUM>, <NUM> is coupled to the control part <NUM> in order to alter the mixing of the aerosols (and more generally the user experience). However, it should be appreciated in some implementations, the mouthpiece part <NUM> may be coupled to the control part <NUM> in any suitable manner, e.g., via a hinge or via a tether.

Thus, there has been described an aerosol provision device for generating aerosol to be inhaled by a user from a plurality of discrete aerosol generating areas each containing an aerosol generating component, the aerosol provision device comprising: a mouthpiece from which a user inhales generated aerosol during use; a first flow pathway arranged to pass through a first aerosol generating area and fluidly connected to the mouthpiece; and a second flow pathway arranged to pass through a second aerosol generating area and fluidly connected to the mouthpiece, wherein the first and second flow pathways are each provided with a flow restriction member configured to vary the flow of air through the respective flow pathways based on the presence of an aerosol generating component in the respective aerosol generating areas in the device and / or a parameter associated with the respective aerosol generating component in the device.

Thus, there has been described an aerosol provision device for generating aerosol for user inhalation, the aerosol provision device comprising: a first aerosol generating area and a second aerosol generating area each for receiving an aerosol precursor material; a mouthpiece from which a user inhales generated aerosol during use, wherein the mouthpiece comprises first and second mouthpiece openings; a first pathway extending from the first aerosol generating area to the first mouthpiece opening for transporting a first aerosol generated from the aerosol precursor material in the first aerosol generating area; and a second pathway extending from the second aerosol generating area chamber to the second mouthpiece opening for transporting a second aerosol generated from the aerosol precursor material in the second aerosol generating area, wherein the first and second pathways are physically isolated from one another to prevent mixing of the first and second aerosols as the first and second aerosols are transported along the respective pathways.

Thus, there has been described an aerosol provision device for generating aerosol from a plurality of aerosol generating areas each configured to receive an aerosol precursor material, wherein the aerosol provision device comprises: a power source for providing power to a first atomising element configured to generate aerosol from a first aerosol precursor material present in the first aerosol generating area and to a second atomising element configured to generate aerosol from a second aerosol precursor material present in a second aerosol generating area; and power distribution circuitry configured to distribute power between the first and second atomising elements based on at least one parameter of aerosol precursor material currently present in the first and second aerosol generating areas respectively.

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

Claim 1:
An aerosol provision device (<NUM>) for generating aerosol for user inhalation, the aerosol provision device comprising:
a first aerosol generating area (43a, 44a, 24a) and a second aerosol generating area (43b, 44b, 24b) each for receiving an aerosol precursor material;
a mouthpiece (<NUM>) from which a user inhales generated aerosol during use, wherein the mouthpiece comprises first and second mouthpiece openings (31a, 31b);
a first pathway (33a, 44a) extending from the first aerosol generating area to the first mouthpiece opening for transporting a first aerosol generated from the aerosol precursor material in the first aerosol generating area, wherein the first aerosol is able to exit the aerosol provision device through the first mouthpiece opening; and
a second pathway (33b, 44b) extending from the second aerosol generating area to the second mouthpiece opening for transporting a second aerosol generated from the aerosol precursor material in the second aerosol generating area, wherein the second aerosol is able to exit the aerosol provision device through the second mouthpiece opening, and
wherein the first and second pathways are physically isolated from one another to prevent mixing of the first and second aerosols as the first and second aerosols are transported along the respective pathways such that the first aerosol and the second aerosol are not permitted to mix within the aerosol provision device during normal use.