Patent Description:
Many electronic vapour provision systems, such as e-cigarettes and other electronic nicotine delivery systems that deliver nicotine via vaporised liquids, are formed from two main components or sections, namely a cartridge or cartomiser section and a control unit (battery section). The cartomiser generally includes a reservoir of liquid and an atomiser for vaporising the liquid. These parts may collectively be designated as an aerosol source. The atomiser generally combines the functions of porosity or wicking and heating in order to transport liquid from the reservoir to a location where it is heated and vaporised. For example, it may be implemented as an electrical heater, which may be a resistive wire formed into a coil or other shape for resistive (Joule) heating or a susceptor for induction heating, and a porous element with capillary or wicking capability in proximity to the heater which absorbs liquid from the reservoir and carries it to the heater. The control unit generally includes a battery for supplying power to operate the system. Electrical power from the battery is delivered to activate the heater, which heats up to vaporise a small amount of liquid delivered from the reservoir. The vaporised liquid is then inhaled by the user.

The components of the cartomiser can be intended for short term use only, so that the cartomiser is a disposable component of the system, also referred to as a consumable. In contrast, the control unit is typically intended for multiple uses with a series of cartomisers, which the user replaces as each expires. Consumable cartomisers are supplied to the consumer with a reservoir pre-filled with liquid, and intended to be disposed of when the reservoir is empty. For convenience and safety, the reservoir is sealed and designed not to be easily refilled, since the liquid may be difficult to handle. It is simpler for the user to replace the entire cartomiser when a new supply of liquid is needed.

In this context, it is desirable that cartomisers are straightforward to manufacture and comprise few parts. They can hence be efficiently manufactured in large quantities at low cost with minimum waste. Cartomisers of a simple design are hence of interest.

<CIT> describes an aerosol delivery device that includes a substrate configured to carry an aerosol precursor composition, and includes an induction transmitter, induction receiver and control component. The induction transmitter is configured to generate an oscillating magnetic field. The induction receiver is positioned in proximity to the substrate, and configured to generate heat when exposed to the oscillating magnetic field and thereby vaporize components of the aerosol precursor composition. The control component is configured to direct current to the induction transmitter to drive the induction transmitter to generate the oscillating magnetic field, with the control component being configured to direct the current according to a zero voltage switching (ZVS) inverter topology.

<CIT> describes a vaporizer device including a cartridge configured to hold a vaporizable substance, a wick element coupled to the cartridge, where the wick element is configured to contact the vaporizable substance located in the cartridge and an induction heating element inductively coupled to the wick element, where the wick element is configured to heat the vaporizable substance based on induction heating of the wick element by the induction heating element.

<CIT> describes an electronic vapour provision system having a longitudinal axis. The electronic vapour provision system comprises a control unit and at least one cartridge configured to engage with and disengage from the control unit substantially along said longitudinal axis. The at least one cartridge includes a reservoir of liquid to be vaporised. The electronic vapour provision system further comprises an induction heating assembly comprising at least one drive coil and a plurality of heater elements. The heater elements are located in the at least one cartridge for vaporising said liquid. The at least one cartridge is configured to feed liquid from the reservoir onto the heater elements for vaporisation. The at least one cartridge is located, when engaged with the control unit, such that the heater elements are within the at least one drive coil. The electronic vapour provision system is configured to support selective energisation of different heater elements from the plurality of heater elements.

According to a first aspect of some embodiments described herein, there is provided an aerosol source for an electronic vapour provision system, comprising: a reservoir housing defining a reservoir for holding aerosolisable substrate material; and an elongate atomiser to which aerosolisable substrate material from the reservoir is deliverable for vaporisation, the atomiser having a porosity and comprising a susceptor for induction heating, and having a first end and a second end, the atomiser mounted at one of its ends only so as to be supported at the mounted end in a cantilevered arrangement having an unsupported cantilever portion, such that the susceptor extends outwardly with respect to an exterior boundary of the reservoir housing.

According to a second aspect of some embodiments described herein, there is provided a cartridge for an electronic vapour provision system comprising an aerosol source according to the first aspect.

According to a third aspect of some embodiments described herein, there is provided an electronic vapour provision system comprising an aerosol source according to the first aspect or a cartridge according to the second aspect, and further comprising a coil configured to receive electrical power in order to heat the susceptor by induction heating.

These and further aspects of the certain embodiments are set out in the appended independent and dependent claims. Furthermore, the approach described herein is not restricted to specific embodiments such as set out below, but includes and contemplates any appropriate combinations of features presented herein. For example, an atomiser or a vapour provision system including an atomiser may be provided in accordance with approaches described herein which includes any one or more of the various features described below as appropriate.

Various embodiments of the invention will now be described in detail by way of example only with reference to the following drawings in which:.

As described above, the present disclosure relates to (but is not limited to) electronic aerosol or vapour provision systems, such as e-cigarettes. Throughout the following description the terms "e-cigarette" and "electronic cigarette" may sometimes be used; however, it will be appreciated these terms may be used interchangeably with aerosol (vapour) provision system or device. The systems are intended to generate an inhalable aerosol by vaporisation of a substrate in the form of a liquid or gel which may or may not contain nicotine. Additionally, hybrid systems may comprise a liquid or gel substrate plus a solid substrate which is also heated. The solid substrate may be for example tobacco or other non-tobacco products, which may or may not contain nicotine. The term "aerosolisable substrate material" as used herein is intended to refer to substrate materials which can form an aerosol, either through the application of heat or some other means. The term "aerosol" may be used interchangeably with "vapour".

As used herein, the term "component" is used to refer to a part, section, unit, module, assembly or similar of an electronic cigarette or similar device that incorporates several smaller parts or elements, possibly within an exterior housing or wall. An electronic cigarette may be formed or built from one or more such components, and the components may be removably or separably connectable to one another, or may be permanently joined together during manufacture to define the whole electronic cigarette. The present disclosure is applicable to (but not limited to) systems comprising two components separably connectable to one another and configured, for example, as an aerosolisable substrate material carrying component holding liquid or another aerosolisable substrate material (a cartridge, cartomiser or consumable), and a control unit having a battery for providing electrical power to operate an element for generating vapour from the substrate material. For the sake of providing a concrete example, in the present disclosure, a cartomiser is described as an example of the aerosolisable substrate material carrying portion or component, but the disclosure is not limited in this regard and is applicable to any configuration of aerosolisable substrate material carrying portion or component. Also, such a component may include more or fewer parts than those included in the examples.

The present disclosure is particularly concerned with vapour provision systems and components thereof that utilise aerosolisable substrate material in the form of a liquid or a gel which is held in a reservoir, tank, container or other receptacle comprised in the system. An arrangement for delivering the substrate material from the reservoir for the purpose of providing it for vapour / aerosol generation is included. The terms "liquid", "gel", "fluid", "source liquid", "source gel", "source fluid" and the like may be used interchangeably with "aerosolisable substrate material" and "substrate material" to refer to aerosolisable substrate material that has a form capable of being stored and delivered in accordance with examples of the present disclosure.

<FIG> is a highly schematic diagram (not to scale) of a generic example aerosol/vapour provision system such as an e-cigarette <NUM>, presented for the purpose of showing the relationship between the various parts of a typical system and explaining the general principles of operation. The e-cigarette <NUM> has a generally elongate shape in this example, extending along a longitudinal axis indicated by a dashed line, and comprises two main components, namely a control or power component, section or unit <NUM>, and a cartridge assembly or section <NUM> (sometimes referred to as a cartomiser or clearomiser) carrying aerosolisable substrate material and operating as a vapour-generating component.

The cartomiser <NUM> includes a reservoir <NUM> containing a source liquid or other aerosolisable substrate material comprising a formulation such as liquid or gel from which an aerosol is to be generated, for example containing nicotine. As an example, the source liquid may comprise around <NUM> to <NUM>% nicotine and <NUM>% glycerol, with the remainder comprising roughly equal measures of water and propylene glycol, and possibly also comprising other components, such as flavourings. Nicotine-free source liquid may also be used, such as to deliver flavouring. A solid substrate (not illustrated), such as a portion of tobacco or other flavour element through which vapour generated from the liquid is passed, may also be included. The reservoir <NUM> has the form of a storage tank, being a container or receptacle in which source liquid can be stored such that the liquid is free to move and flow within the confines of the tank. For a consumable cartomiser, the reservoir <NUM> may be sealed after filling during manufacture so as to be disposable after the source liquid is consumed, otherwise, it may have an inlet port or other opening through which new source liquid can be added by the user. The cartomiser <NUM> also comprises an electrically powered heating element or heater <NUM> located externally of the reservoir tank <NUM> for generating the aerosol by vaporisation of the source liquid by heating. A liquid transfer or delivery arrangement (liquid transport element) such as a wick or other porous element <NUM> may be provided to deliver source liquid from the reservoir <NUM> to the heater <NUM>. A wick <NUM> may have one or more parts located inside the reservoir <NUM>, or otherwise be in fluid communication with the liquid in the reservoir <NUM>, so as to be able to absorb source liquid and transfer it by wicking or capillary action to other parts of the wick <NUM> that are adjacent or in contact with the heater <NUM>. This liquid is thereby heated and vaporised, to be replaced by new source liquid from the reservoir for transfer to the heater <NUM> by the wick <NUM>. The wick may be thought of as a bridge, path or conduit between the reservoir <NUM> and the heater <NUM> that delivers or transfers liquid from the reservoir to the heater. Terms including conduit, liquid conduit, liquid transfer path, liquid delivery path, liquid transfer mechanism or element, and liquid delivery mechanism or element may all be used interchangeably herein to refer to a wick or corresponding component or structure.

A heater and wick (or similar) combination is sometimes referred to as an atomiser or atomiser assembly, and the reservoir with its source liquid plus the atomiser may be collectively referred to as an aerosol source. Other terminology may include a liquid delivery assembly or a liquid transfer assembly, where in the present context these terms may be used interchangeably to refer to a vapour-generating element (vapour generator) plus a wicking or similar component or structure (liquid transport element) that delivers or transfers liquid obtained from a reservoir to the vapour generator for vapour / aerosol generation. Various designs are possible, in which the parts may be differently arranged compared with the highly schematic representation of <FIG>. For example, the wick <NUM> may be an entirely separate element from the heater <NUM>, or the heater <NUM> may be configured to be porous and able to perform at least part of the wicking function directly (a metallic mesh, for example). In an electrical or electronic device, the vapour generating element may be an electrical heating element that operates by ohmic/resistive (Joule) heating or by inductive heating. In general, therefore, an atomiser can be considered as one or more elements that implement the functionality of a vapour-generating or vaporising element able to generate vapour from source liquid delivered to it, and a liquid transport or delivery element able to deliver or transport liquid from a reservoir or similar liquid store to the vapour generator by a wicking action / capillary force. An atomiser is typically housed in a cartomiser component of a vapour generating system. In some designs, liquid may be dispensed from a reservoir directly onto a vapour generator with no need for a distinct wicking or capillary element. Embodiments of the disclosure are applicable to all and any such configurations which are consistent with the examples and description herein.

Returning to <FIG>, the cartomiser <NUM> also includes a mouthpiece or mouthpiece portion <NUM> having an opening or air outlet through which a user may inhale the aerosol generated by the atomiser <NUM>.

The power component or control unit <NUM> includes a cell or battery <NUM> (referred to herein after as a battery, and which may be re-chargeable) to provide power for electrical components of the e-cigarette <NUM>, in particular to operate the heater <NUM>. Additionally, there is a controller <NUM> such as a printed circuit board and/or other electronics or circuitry for generally controlling the e-cigarette. The control electronics/circuitry <NUM> operates the heater <NUM> using power from the battery <NUM> when vapour is required, for example in response to a signal from an air pressure sensor or air flow sensor (not shown) that detects an inhalation on the system <NUM> during which air enters through one or more air inlets <NUM> in the wall of the control unit <NUM>. When the heating element <NUM> is operated, the heating element <NUM> vaporises source liquid delivered from the reservoir <NUM> by the liquid delivery element <NUM> to generate the aerosol, and this is then inhaled by a user through the opening in the mouthpiece <NUM>. The aerosol is carried from the aerosol source to the mouthpiece <NUM> along one or more air channels (not shown) that connect the air inlet <NUM> to the aerosol source to the air outlet when a user inhales on the mouthpiece <NUM>.

The control unit (power section) <NUM> and the cartomiser (cartridge assembly) <NUM> are separate connectable parts detachable from one another by separation in a direction parallel to the longitudinal axis, as indicated by the double-ended arrows in <FIG>. The components <NUM>, <NUM> are joined together when the device <NUM> is in use by cooperating engagement elements <NUM>, <NUM> (for example, a screw or bayonet fitting) which provide mechanical and in some cases electrical connectivity between the power section <NUM> and the cartridge assembly <NUM>. Electrical connectivity is required if the heater <NUM> operates by ohmic heating, so that current can be passed through the heater <NUM> when it is connected to the battery <NUM>. In systems that use inductive heating, electrical connectivity can be omitted if no parts requiring electrical power are located in the cartomiser <NUM>. An inductive work coil can be housed in the power section <NUM> and supplied with power from the battery <NUM>, and the cartomiser <NUM> and the power section <NUM> shaped so that when they are connected, there is an appropriate exposure of the heater <NUM> to flux generated by the coil for the purpose of generating current flow in the material of the heater. Inductive heating arrangements are discussed further below. The <FIG> design is merely an example arrangement, and the various parts and features may be differently distributed between the power section <NUM> and the cartridge assembly section <NUM>, and other components and elements may be included. The two sections may connect together end-to-end in a longitudinal configuration as in <FIG>, or in a different configuration such as a parallel, side-by-side arrangement. The system may or may not be generally cylindrical and/or have a generally longitudinal shape. Either or both sections or components may be intended to be disposed of and replaced when exhausted (the reservoir is empty or the battery is flat, for example), or be intended for multiple uses enabled by actions such as refilling the reservoir and recharging the battery. In other examples, the system <NUM> may be unitary, in that the parts of the control unit <NUM> and the cartomiser <NUM> are comprised in a single housing and cannot be separated. Embodiments and examples of the present disclosure are applicable to any of these configurations and other configurations of which the skilled person will be aware.

<FIG> shows an external perspective view of parts which can be assembled to form a cartomiser according to an example of the present disclosure. The cartomiser <NUM> comprises four parts only, which can be assembled by being pushed or pressed together if appropriately shaped. Hence, fabrication can be made very simple and straightforward.

A first part is a housing <NUM> that defines a reservoir for holding aerosolisable substrate material (hereinafter referred to as a substrate or a liquid, for brevity). The housing <NUM> has a generally tubular shape, which in this example has a circular cross-section, and comprises a wall or walls shaped to define various parts of the reservoir and other items. A cylindrical outer side wall <NUM> is open at its lower end at an opening <NUM> through which the reservoir may be filled with liquid, and to which parts can be joined as described below, to close/seal the reservoir and also enable an outward delivery of the liquid for vaporisation. This defines an exterior or external volume or dimensions of the reservoir. References herein to elements or parts lying or being located externally to the reservoir are intended to indicate that the part is outside or partially outside the region bounded or defined by this outer wall <NUM> and its upper and lower extent and edges or surfaces.

A cylindrical inner wall <NUM> is concentrically arranged within the outer side wall <NUM>. This arrangement defines an annular volume <NUM> between the outer wall <NUM> and the inner wall <NUM> which is a receptacle, cavity, void or similar to hold liquid, in other words, the reservoir. The outer wall <NUM> and the inner wall <NUM> are connected together (for example by a top wall or by the walls tapering towards one another) in order to close the upper edge of the reservoir volume <NUM>. The inner wall <NUM> is open at its lower end at an opening <NUM>, and also at its upper end. The tubular inner space bounded by the inner wall is an air flow passage or channel <NUM> that, in the assembled system, carries generated aerosol from an atomiser to a mouthpiece outlet of the system for inhalation by a user. The opening <NUM> at the upper end of the inner wall <NUM> can be the mouthpiece outlet, configured to be comfortably received in the user's mouth, or a separate mouthpiece part can be coupled on or around the housing <NUM> having a channel connecting the opening <NUM> to a mouthpiece outlet.

The housing <NUM> may be formed from moulded plastic material, for example by injection moulding. In the example of <FIG>, it is formed from transparent material; this allows the user to observe a level or amount of liquid in the reservoir <NUM>. The housing might alternatively be opaque, or opaque with a transparent window through which the liquid level can be seen. The plastic material may be rigid in some examples.

A second part of the cartomiser <NUM> is a flow directing member <NUM>, which in this example also has a circular cross-section, and is shaped and configured for engagement with the lower end of the housing <NUM>. The flow directing member <NUM> is effectively a bung, and is configured to provide a plurality of functions. When inserted into the lower end of the housing <NUM>, it couples with the opening <NUM> to close and seal the reservoir volume <NUM> and couples with the opening <NUM> to seal off the air flow passage <NUM> from the reservoir volume <NUM>. Additionally, the flow directing member <NUM> has at least one channel passing through it for liquid flow, which carries liquid from the reservoir volume <NUM> to a space external to the reservoir which acts as an aerosol chamber where vapour/aerosol is generated by heating the liquid. Also the flow directing member <NUM> has at least one other channel passing through it for aerosol flow, which carries the generated aerosol from the aerosol chamber space to the air flow passage <NUM> in the housing <NUM>, so that it is delivered to the mouthpiece opening for inhalation.

Also, the flow directing member <NUM> may be made from a flexible resilient material such as silicone so that it can be easily engaged with the housing <NUM> via a friction fit. Additionally, the flow directing member has a socket or similarly-shaped formation (not shown) on its lower surface <NUM>, opposite to the upper surface or surfaces <NUM> which engage with the housing <NUM>. The socket receives and supports an atomiser <NUM>, being a third part of the cartomiser <NUM>.

The atomiser <NUM> has an elongate shape with a first end <NUM> and a second end <NUM> oppositely disposed with respect to its elongate length. In the assembled cartomiser, the atomiser is mounted at its first end <NUM> which pushed into the socket of the flow directing member <NUM> in a direction towards the reservoir housing <NUM>. The first end <NUM> is therefore supported by the flow directing member <NUM>, and the atomiser <NUM> extends lengthwise outwardly from the reservoir substantially along the longitudinal axis defined by the concentrically shaped parts of the housing <NUM>. The second end <NUM> of the atomiser <NUM> is not mounted, and is left free. Accordingly, the atomiser <NUM> is supported in a cantilevered manner extending outwardly from the exterior bounds of the reservoir. The atomiser <NUM> performs a wicking function and a heating function in order to generate aerosol, and may comprise any of several configurations of an electrically resistive heater portion configured to act as an inductive susceptor, and a porous portion configured to wick liquid from the reservoir to the vicinity of the heater.

A fourth part of the cartomiser <NUM> is an enclosure or shroud <NUM>. Again, this has a circular cross-section in this example. It comprises a cylindrical side wall <NUM> closed by a an optional base wall to define a central hollow space or void <NUM>. The upper rim <NUM> of the side wall <NUM>, around an opening <NUM>, is shaped to enable engagement of the enclosure <NUM> with reciprocally shaped parts on the flow directing member <NUM> so that the enclosure <NUM> can be coupled to the flow directing member <NUM> once the atomiser <NUM> is fitted into the socket on the flow directing member <NUM>. The flow directing member <NUM> hence acts as a cover to close the central space <NUM>, and this space <NUM> creates an aerosol chamber in which the atomiser <NUM> is disposed. The opening <NUM> allows communication with the liquid flow channel and the aerosol flow channel in the flow directing member <NUM> so that liquid can be delivered to the atomiser and generated aerosol can be removed from the aerosol chamber. In order to enable a flow of air through the aerosol chamber to pass over the atomiser <NUM> and collect the vapour such that it becomes entrained in the air flow to form an aerosol, the wall or walls <NUM> of the enclosure <NUM> have one or more openings or perforations to allow air to be drawn into the aerosol chamber when a user inhales via the mouthpiece opening of the cartomiser.

The enclosure <NUM> may be formed from a plastics material, such as by injection moulding. It may be formed from a rigid material, and can then be readily engaged with the flow directing member by pushing or pressing the two parts together.

As noted above, the flow directing member can be made from a flexible resilient material, and may hold the parts coupled to it, namely the housing <NUM>, the atomiser <NUM> and the enclosure <NUM>, by friction fit. Since these parts may be more rigid, the flexibility of the flow directing member, which enables it to deform somewhat when pressed against these other parts, accommodates any minor errors in the manufactured size of the parts. In this way, the flow directing part can absorb manufacturing tolerances of all the parts while still enabling quality assembly of the parts altogether to form the cartomiser <NUM>. Manufacturing requirements for making the housing <NUM>, the atomiser <NUM> and the enclosure <NUM> can therefore be relaxed somewhat, reducing manufacturing costs.

<FIG> shows a cut-away perspective view of the cartomiser of <FIG> in an assembled configuration. For clarity, the flow directing member <NUM> is shaded. It can be seen how the flow directing member <NUM> is shaped on its upper surfaces to engage around the opening <NUM> defined by the lower edge of the inner wall <NUM> of the reservoir housing <NUM>, and concentrically outwardly to engage in the opening <NUM> defined by the lower edge of the outer wall <NUM> of the housing <NUM>, in order to seal both reservoir space <NUM> and the air flow passage <NUM>.

The flow directing member <NUM> has a liquid flow channel <NUM> which allows the flow of liquid substrate material L from the reservoir volume <NUM> through the flow directing member into a space or volume <NUM> under the flow directing member <NUM>. Also, there is an aerosol flow channel <NUM> which allows the flow of aerosol and air A from the space <NUM> through the flow directing member <NUM> to the air flow passage <NUM>.

The enclosure <NUM> is shaped at its upper rim to engage with corresponding shaped parts in the lower surface of the flow directing member <NUM>, to create the aerosol chamber <NUM> substantially outside the exterior dimensions of the volume of the reservoir <NUM> according to the reservoir housing <NUM>. In this example, the enclosure <NUM> has an aperture <NUM> in its upper end proximate the flow directing member <NUM>. This coincides with the space <NUM> with which the liquid flow channel <NUM> and the aerosol flow channel <NUM> communicate, and hence allows liquid to enter the aerosol chamber <NUM> and aerosol to leave the aerosol chamber <NUM> via the channels in the flow directing member <NUM>.

In this example, the aperture <NUM> also acts as a socket for mounting the first, supported, end <NUM> of the atomiser <NUM> (recall that in the <FIG> description, the atomiser socket was mentioned as being formed in the flow directing member, either option can be used). Thus, liquid arriving through the liquid flow channel <NUM> is fed directly to the first end of the atomiser <NUM> for absorption and wicking, and air/aerosol can be drawn through and past the atomiser to enter the aerosol flow channel <NUM>.

In this example, the atomiser <NUM> comprises a planar elongate portion of metal <NUM> which is folded or curved at its midpoint to bring the two ends of the metal portion adjacent to one another at the first end of the atomiser <NUM>. This acts as the heater component of the atomiser <NUM>. A portion of cotton or other porous material <NUM> is sandwiched between the two folded sides of the metal portion. This acts as the wicking component of the atomiser <NUM>. Liquid arriving in the space <NUM> is collected by the absorbency of the porous wick material <NUM> and carried downwards to the heater. Many other arrangements of an elongate atomiser suitable for cantilevered mounting are also possible and may be used instead.

The heater component is intended for heating via induction, which will be described further below.

The example of <FIG> and <FIG> has parts with substantially circular symmetry in a plane orthogonal to the longitudinal dimension of the assembled cartomiser. Hence, the parts are free from any required orientation in the planes in which they are joined together, which can give ease of manufacture. The parts can be assembled together in any orientation about the axis of the longitudinal dimension, so there is no requirement to place the parts in a particular orientation before assembly. This is not essential, however, and the parts may be alternatively shaped.

<FIG> shows a cross-sectional view through a further example assembled cartomiser comprising a reservoir housing, a flow directing member, an atomiser and an enclosure, as before. In this example, though, in the plane orthogonal to the longitudinal axis of the cartomiser <NUM>, at least some of the parts have an oval shape instead of a circular shape, and are arranged to have symmetry along the major axis and the minor axis of the oval. Features are reflected on either side of the major axis and on either side of the minor axis. This means that for assembly the parts can have either of two orientations, rotated from each other by <NUM>° about the longitudinal axis. Again, assembly is simplified compared to a system comprising parts with no symmetry.

In this example, the enclosure <NUM> again comprises a side wall <NUM>, which is formed so as to have a varying cross-section at different points along the longitudinal axis of the enclosure, and a base wall <NUM>, which bound a space that creates the aerosol chamber <NUM>. Towards its upper end, the enclosure broadens out to a large cross-section to give room to accommodate the flow directing member <NUM>. The large cross-section portion of the enclosure <NUM> has a generally oval cross-section (see <FIG>), while the narrower cross-section portion of the enclosure has a generally circular cross-section (see <FIG>). The enclosure's upper rim <NUM>, around the top opening <NUM>, is shaped to engage with corresponding shaping on the reservoir housing <NUM>. This shaping and engagement is shown in simplified form in <FIG>; in reality it is likely to be more complex in order to provide a reasonably air-tight and liquid-tight join. The enclosure <NUM> has at least one opening <NUM>, in this case in the base wall <NUM>, to allow air to enter the aerosol chamber during user inhalation.

The reservoir housing <NUM> is differently shaped compared with the <FIG> and <FIG> example. The outer wall <NUM> defines an interior space which is divided into three regions by two inner walls <NUM>. The regions are arranged side by side. The central region, between the two inner walls <NUM> is the reservoir volume <NUM> for holding liquid. This region is closed at the top by a top wall of the housing. An opening <NUM> in the base of the reservoir volume allows liquid to be delivered from the reservoir <NUM> to the aerosol chamber <NUM>. The two side regions, between the outer wall <NUM> and the inner walls <NUM>, are the air flow passages <NUM>. Each has an opening <NUM> at its lower end for aerosol to enter, and a mouthpiece opening <NUM> at its upper end (as before, a separate mouthpiece portion might be added externally to the reservoir housing <NUM>).

A flow directing member <NUM> (shaded for clarity) is engaged into the lower edge of the housing <NUM>, via shaped portions to engage with the openings <NUM> and <NUM> in the housing <NUM> to close/seal the reservoir volume <NUM> and the air flow passages <NUM>. The flow directing member <NUM> has a single centrally disposed liquid flow channel <NUM> aligned with the reservoir volume opening <NUM> to transport liquid L from the reservoir to the aerosol chamber <NUM>. Further, there are two aerosol flow channels <NUM>, each running from an inlet at the aerosol chamber <NUM> to an outlet to the air flow passages <NUM>, by which air entering the aerosol chamber through the hole <NUM> and collecting vapour in the aerosol chamber <NUM> flows into the air flow passages <NUM> to the mouthpiece outlets <NUM>.

The atomiser <NUM> is mounted by insertion of its first end <NUM> into the liquid flow channel <NUM> of the flow directing component <NUM>. Hence, in this example, the liquid flow channel <NUM> acts as a socket for the cantilevered mounting of the atomiser <NUM>. The first end <NUM> of the atomiser <NUM> is thus directly fed with liquid entering the liquid flow channel <NUM> from the reservoir <NUM>, and the liquid is taken up via the porous properties of the atomiser <NUM> and drawn along the atomiser length to be heated by the heater portion of the atomiser <NUM> (not shown) which is located in the aerosol chamber <NUM>.

<FIG> show cross-sections through the cartomiser <NUM> at the corresponding positions along the longitudinal axis of the cartomiser <NUM>.

While aspects of the disclosure are relevant to atomisers in which the heating aspect is implemented via resistive heating, which requires electrical connections to be made to a heating element for the passage of current, the design of the cartomiser has particular relevance to the use of induction heating. This is a process by which a electrically conducting item, typically made from metal, is heated by electromagnetic induction via eddy currents flowing in the item which generates heat. An induction coil (work coil) operates as an electromagnet when a high-frequency alternating current from an oscillator is passed through it; this produces a magnetic field. When the conducting item is placed in the flux of the magnetic field, the field penetrates the item and induces electric eddy currents. These flow in the item, and generate heat according to current flow against the electrical resistance of the item via Joule heating, in the same manner as heat is produced in a resistive electrical heating element by the direct supply of current. An attractive feature of induction heating is that no electrical connection to the conducting item is needed; the requirement instead is that a sufficient magnetic flux density is created in the region occupied by the item. In the context of vapour provision systems, where heat generation is required in the vicinity of liquid, this is beneficial since a more effective separation of liquid and electrical current can be effected. Assuming no other electrically powered items are placed in a cartomiser, there is no need for any electrical connection between a cartomiser and its power section, and a more effective liquid barrier can be provided by the cartomiser wall, reducing the likelihood of leakage.

Induction heating is effective for the direct heating of an electrically conductive item, as described above, but can also be used to indirectly heat non-conducting items. In a vapour provision system, the need is to provide heat to liquid in the porous wicking part of the atomiser in order to cause vaporisation. For indirect heating via induction, the electrically conducting item is placed adjacent to or in contact with the item in which heating is required, and between the work coil and the item to be heated. The work coil heats the conducting item directly by induction heating, and heat is transferred by thermal radiation or thermal conduction to the non-conducting item. In this arrangement, the conducting item is termed a susceptor. Hence, in an atomiser, the heating component can be provided by an electrically conductive material (typically metal) which is used as an induction susceptor to transfer heat energy to a porous part of the atomiser.

<FIG> shows a highly simplified schematic representation of a vapour provision system comprising a cartomiser <NUM> according to examples of the present disclosure and a power component <NUM> configured for induction heating. The cartomiser <NUM> may be as shown in the examples of <FIG>, <FIG> and <FIG> (although other arrangements are not excluded), and is shown in outline only for simplicity. The cartomiser <NUM> comprises an atomiser <NUM> in which the heating is achieved by induction heating so that the heating function is provided by a susceptor (not indicated separately). The atomiser <NUM> is located in the lower part of the cartomiser <NUM>, surrounded by the enclosure <NUM>, which acts not only to define an aerosol chamber but also to provide a degree of protection for the atomiser <NUM>, which could be relatively vulnerable to damage owing to its cantilevered mounting. The cantilever mounting of the atomiser enables effective induction heating however, because the atomiser <NUM> can be inserted into the inner space of a coil <NUM>, and in particular, the reservoir is positioned away from the inner space of the work coil <NUM>. Hence, the power component <NUM> comprises a recess <NUM> into which the enclosure <NUM> of the cartomiser <NUM> is received when the cartomiser <NUM> is coupled to the power component for use (via a friction fit, a clipping action, a screw thread, or a magnetic catch, for example). An induction work coil <NUM> is located in the power component <NUM> so as to surround the recess <NUM>, the coil <NUM> having a longitudinal axis over which the individual turns of the coil extend and a length which substantially matches the length of the susceptor so that the coil <NUM> and the susceptor overlap when the cartomiser <NUM> and the power component <NUM> are joined. In other implementations, the length of the coil may not substantially match the length of the susceptor, e.g., the length of the susceptor may be shorter than the length of the coil, or the length of the susceptor may be longer than the length of the coil. In this way, the susceptor is located within the magnetic field generated by the coil <NUM>. If the items are located so that the separation of the susceptor from the surrounding coil is minimised, the flux experienced by the susceptor can be higher and the heating effect made more efficient. However, the separation is set at least in part by the width of aerosol chamber formed by the enclosure <NUM>, which needs to be sized to allow adequate air flow over the atomiser and to avoid liquid droplet entrapment. Hence, these two requirements need to be balanced against one another when determining the sizing and positioning of the various items.

The power component <NUM> comprises a battery <NUM> for the supply of electrical power to energise the coil <NUM> at an appropriate AC frequency. Also, there is included a controller <NUM> to control the power supply when vapour generation is required, and possibly to provide other control functions for the vapour provision system which are not considered further here. The power component may also include other parts, which are not shown and which are not relevant to the present discussion.

The <FIG> example is a linearly arranged system, in which the power component <NUM> and the cartomiser <NUM> are coupled end-to-end to achieve a pen-like shape.

<FIG> shows a simplified schematic representation of an alternative design, in which the cartomiser <NUM> provides a mouthpiece for a more box-like arrangement, in which the battery <NUM> is disposed in the power component <NUM> to one side of the cartomiser <NUM>. Other arrangements are also possible.

The atomiser <NUM> may be configured in any of several ways that provide it both with porosity in order to absorb liquid from the reservoir and carry it to the susceptor, and with electrical resistance/conductivity in order for the susceptor to operate as a heater to vaporise the liquid. Hence, the atomiser can broadly be defined as having porosity and comprising a susceptor for induction heating. Various examples for implementing these functions are described further below.

Regardless of the implementation of the porosity and induction heating capabilities, the atomiser <NUM> has an elongate shape extending between a first end and a second end. By "elongate" it is meant that the atomiser is dimensioned such that its size (length) in a direction extending between the first end and the second end is larger, typically significantly larger, that its size (width) in a direction orthogonal to the length. For example, the length may be at least two times the width, or at least five times the width, or at least ten times the width. These are examples only and other proportions are not excluded.

Furthermore, the elongate atomiser is mounted in a cantilevered arrangement, as noted above.

<FIG> shows a highly schematic representation of an example atomiser mounted to form a cantilever. The atomiser <NUM> has an elongate shape with a length l, being its larger dimension which extends between a first end <NUM> and a second end <NUM>. The atomiser has a width w substantially orthogonal to its length l. The atomiser <NUM> has a porosity attributable to a porous part, portion or element <NUM>, and also comprises a susceptor <NUM> for induction heating made from an electrically conductive/resistive material, for example a metal. In <FIG> the susceptor <NUM> and the porous element <NUM> are shown highly schematically as adjacent components; more detailed arrangements are described in below. However, the susceptor <NUM> includes the second end <NUM> of the atomiser <NUM>, which is located in an aerosol chamber <NUM>.

A socket <NUM>, being an opening or aperture through a component <NUM> which may be a reservoir housing, a flow directing member, or an enclosure, all as described above, or indeed some other component, is utilised in order to support the atomiser <NUM> in a cantilevered configuration. This is achieved by inserting the first end <NUM> of the atomiser <NUM> into the socket <NUM>. The socket <NUM> is sized so as to have a width (or cross-sectional area) the same as or similar to the width w (or cross-sectional area) of the atomiser <NUM> so that the atomiser <NUM> is gripped within the socket <NUM>. If the component <NUM> in which the socket <NUM> is formed is made from a flexible resilient material such as silicone or rubber (natural or synthetic), the atomiser <NUM> can be held securely gripped by the socket <NUM>, perhaps due to some compression of the socket material by the inserted atomiser. Otherwise a friction fit may be utilised if the materials of the socket <NUM> and the atomiser first end <NUM> have suitable surface properties. Alternatively, adhesive or a similar material might be used to permanently or temporarily fix the atomiser <NUM> in place within the socket <NUM>.

The location of the atomiser <NUM> in the socket <NUM> demarcates two zones or portions of the atomiser <NUM>, divided by the plane <NUM> which is in line with the face of the socket <NUM> facing the aerosol chamber <NUM>. The portion of the atomiser <NUM> lying between the plane <NUM> and the first end <NUM> of the atomiser <NUM> inserted into the socket <NUM> is a supported or mounted portion <NUM>, since it is supported by the socket <NUM>. In this example, the supported portion is wholly surrounded or encircled by the socket <NUM>. The portion of the atomiser <NUM> lying between the plane <NUM> and the second end <NUM> of the atomiser <NUM> is an unsupported portion <NUM>, extending outwardly from external dimensions of the reservoir volume <NUM> and within the aerosol chamber <NUM>. The second end <NUM> is therefore unsupported by any physical contact with another component, and the portion <NUM> is a cantilever portion of the atomiser <NUM>. The atomiser <NUM> is therefore held, mounted or supported in a cantilevered arrangement or configuration, with a supported first end <NUM> and an unsupported second end <NUM>. The susceptor <NUM> at least partly, and in this example wholly, comprised within the cantilever portion <NUM> and therefore lies within the aerosol chamber <NUM> and is located outside the external boundaries or dimensions of the reservoir <NUM>.

At noted above, the atomiser <NUM> has a length I. The mounted portion <NUM> has a length l1, and the cantilever portion <NUM> has a length l2, such that l1 + l2 = l. Typically, the cantilever portion <NUM> will have a greater length that the mounted portion <NUM>, so that l2 > l1. With reference to the whole length of the atomiser <NUM>, the mounted portion may therefore occupy less than <NUM>% of the atomiser, so that l1 < l/<NUM>. In more particular examples, l1 may be a proportion of the total length I in the range of substantially <NUM>% to <NUM>%, or <NUM>% to <NUM>%, or <NUM>% to <NUM>%, or substantially <NUM>%.

In terms of numerical values, the length l1 of the mounted portion may in the range of about <NUM> to <NUM>, or about <NUM> to <NUM>, for example about <NUM>. Lengths greater than about <NUM> are typically unnecessary in terms of providing support and hence waste material and increase costs. Lengths less than about <NUM> provide insufficient support and an undesirably weak hold on the atomiser.

A purpose of the cantilevered arrangement of the atomiser <NUM> is to enable the susceptor to be located for efficient coupling of magnetic flux from the work coil that drives the induction heating. For a given flux density, this coupling is made most effective by use of a minimum separation between a susceptor and a coil, and minimum structural features lying between a susceptor and its coil. Therefore, more traditional locations of an electrical heating element in a vapour provision system such as within a region bounded by an outer wall of a reservoir (a typically position for a resistive heating element in the inner space of an annular reservoir) are poorly suited for induction heating, since the presence of the reservoir increases the distance between the coil and the susceptor, and may block or interfere with the magnetic field. The cantilevered arrangement takes the susceptor outside of the reservoir boundaries, and also frees an end of the susceptor/atomiser from physical connection to other components so that the susceptor can be inserted inside a helical induction work coil, enabling close proximity to the coil and hence an efficient coupling of the magnetic flux.

In the <FIG> example, the first end <NUM> of the atomiser <NUM> is inserted into the socket <NUM> so that the end face <NUM> of the first end <NUM> is substantially flush with the face of the socket facing towards the reservoir. This end face <NUM> receives liquid L delivered from the reservoir <NUM> (via a liquid flow channel in a flow directing member, for example), and absorbs the liquid and carries it by wicking towards the second end <NUM> of the atomiser <NUM> so that it comes within the heating range of the susceptor portion <NUM> for vaporisation.

<FIG> shows a schematic representation of an alternative example of a cantilevered atomiser <NUM> held in a socket <NUM> of a component <NUM>. In this example, the first end <NUM> of the atomiser <NUM> is inserted less far into the socket <NUM>, so that the end face <NUM> of the atomiser <NUM> is located at a plane intermediate between the face of the socket <NUM> facing towards the reservoir <NUM> and the face of the socket <NUM> facing towards the aerosol chamber <NUM>. As before, the mounted or supported portion <NUM> has a length l1 that extends between the plane <NUM> and the first end <NUM> of the atomiser <NUM>, although in this case the length l1 is shorter than the depth of the socket <NUM>.

<FIG> shows a schematic representation of an alternative example of a cantilevered atomiser <NUM> held in a socket <NUM> of a component <NUM>. In this example, the first end <NUM> of the atomiser <NUM> is inserted further into the socket <NUM> so that the first end <NUM> protrudes beyond the socket <NUM> and the end face <NUM> is located outside the socket <NUM> on the reservoir side. As before, though, the mounted portion of length l1 is considered to be that part of the atomiser <NUM> that lies between the plane <NUM> and the first end <NUM>, even though a part of the mounted portion <NUM> is external to the socket <NUM> (not surrounded by the material of the component <NUM>). This part is considered to be not relevant compared to the length l2 of the cantilever portion, so can be considered to be mounted as regards the aim of providing a cantilevered atomiser that extends outwardly into an aerosol chamber. The protruding part of the mounted portion <NUM> can be provided so as to give a larger surface area of the atomiser able to receive liquid L arriving from the reservoir <NUM>, thus improving the efficiency of the liquid delivery to the susceptor.

Various designs of atomiser may be utilised in the cantilevered configuration. In some examples, the porosity is provided by use of a porous ceramic component or element that acts as a wick to absorb liquid from the reservoir and carry it by wicking or capillary action to the vicinity of the susceptor. For example, a porous ceramic rod may be used, having a generally elongate shape, and a cross sectional shape that may be substantially circular (which removes any requirement for particular alignment during assembly of a cartomiser), or oval, or square, or rectangular or any other shape. The socket may have a corresponding cross-sectional size and shape, or merely have similar dimensions and a size large enough to accommodate an end of the rod so that the atomiser can be inserted into the socket as required. However, a matching size and shape will provide a better seal to limit leakage of free liquid from the reservoir into the aerosol chamber.

<FIG> shows a cross-sectional side view of an example atomiser based on a porous ceramic rod. As before, the ceramic rod <NUM> extends the full length of the atomiser <NUM>. The susceptor <NUM> is embodied as a metal layer <NUM> which wraps the ceramic rod <NUM> around its outer side surface. The metal layer <NUM> is formed from a planar sheet of metallic material, for example. The sheet may be rolled, folded or curled into a suitable shape that allows the layer to conform to the outer shape and surface of the ceramic rod <NUM>, so as to be in contact or close contact with the outer surface of the rod <NUM>. In this example, the end surface <NUM> of the rod is not covered by the metal layer, but in some examples, the metal layer may cover the end surface <NUM> also. The metal layer <NUM> does not cover the first end of <NUM> of the ceramic rod <NUM>, leaving an uncovered part by which the atomiser <NUM> can be mounted without delivering heat to the supporting socket. The metal layer <NUM> may be provided with perforations or other holes to enable vapour generated from liquid in the porous ceramic rod <NUM> to escape more easily from the atomiser <NUM> into the aerosol chamber <NUM>.

<FIG> show transverse cross-sectional views of various configurations of the example atomiser of <FIG>. Each has a circular shape in this transverse plane, but this is not essential; other shapes may be used. <FIG> shows an example in which the metal layer <NUM> is configured as a hollow tube closed around its circumference (such as by seaming the two edges of a rolled metal sheet), into which the ceramic rod <NUM> can be inserted. <FIG> shows an example in which the metal layer <NUM> is configured again as a hollow tube, but unseamed so that it comprises two edges which overlap in an unjoined manner and are free to slide over one another in an overlap region <NUM> to alter the circumference of the tube. This can be formed by rolling a metal sheet into a tubular shape. This shape allows the tube to be enlarged somewhat for ease of insertion of the ceramic rod <NUM>, and it can contract again after insertion under the biasing forces of the tubular shape, so as to give a close contact of the metal layer <NUM> to the rod <NUM>. <FIG> shows a similar example in which the metal tube has two edges which are not joined to one another, but also do not overlap so that the metal tube <NUM> does not fully encircle the rod <NUM>. A gap <NUM> exists between the two edges of the rolled metal sheet. Again, this allows the tube to be enlarged during assembly of the atomiser and to contract afterwards to contact the outer surface of the rod <NUM>. Also, the gap allows the escape of vapour, so perforations in the metal sheet may not be necessary.

The examples of <FIG> may alternatively be configured with a porous element other than a porous ceramic rod. The hollow tubular shape of the metal sheet layer <NUM> can be filled with porous material such as material comprising fibres (fibrous material), woven, nonwoven, wadded or bundled together in order to form an absorbent structure with pores or capillary gaps. For example, the fibrous material may comprise cotton, including organic cotton.

In any of the <FIG> examples, the susceptor <NUM> may not reach as far as the plane <NUM> between the supported portion <NUM> and the cantilever portion <NUM> of the atomiser or may reach only as far as this plane to avoid delivering heat to the socket material. Alternatively, the susceptor may reach past this plane <NUM>, possibly extending to the first end of the atomiser <NUM>, if the socket material can withstand heat exposure at the temperatures to which the susceptor <NUM> is heated. The end face <NUM> of the ceramic rod <NUM> at the first end <NUM> should be left uncovered by the metallic layer in order to allow ingress of liquid, however.

<FIG> shows a cross-sectional side view of a further example of an atomiser <NUM>, similar to that of <FIG>. The atomiser <NUM> is shown mounted at its first end <NUM> in a socket <NUM> of a component <NUM>, as before. The susceptor <NUM> comprises an elongate planar metal element <NUM> originally twice the desired length of the atomiser <NUM>, which is folded or bent across its width roughly midway along its length in order to bring its two short ends adjacent to one another. These adjacent short ends form the first end <NUM> of the atomiser <NUM> which is inserted into the socket <NUM>. The folded shape may give an outward bias to the two ends (they are biased towards the unfolded configuration of the planar element) so that they press outwardly against the sides of the socket <NUM> and act to keep the atomiser in its mounted position. The fold forms the second end <NUM> of the atomiser <NUM>. The two halves, brought near to one another by the fold, define a volume, space or open cavity to hold a porous element <NUM> for wicking of liquid L from the reservoir to the susceptor <NUM>. The porous element <NUM> is effectively sandwiched between the two halves of the folded susceptor <NUM>. The open sides of the cavity allow the escape of vapour into the aerosol chamber <NUM>. The porous element <NUM> may comprise fibres or fibrous material as described above with regard to <FIG>, such as cotton or porous cotton.

<FIG> shows a cross-sectional side view of a further example of an atomiser <NUM>, again mounted at its first end <NUM> in a socket <NUM> of a component <NUM>. In this example, the atomiser is comprised of a material which is able to provide both the porous wicking function and the susceptor function, and formed from this material as an elongate monolithic element. For example, it may comprise an electrically resistive material such as a metal which is formed into a porous structure, such as by sintering together of metallic fibres or beads, or by weaving or otherwise enmeshing fibres to form a mesh or grid structure. The mesh or grid might be fabricated as a sheet, which could be cut to size and shape and used in its flat form, or folded, rolled or bent into some other shape.

As described with regard to <FIG>, the cartomiser comprises an enclosure placed around the cantilevered atomiser to form an aerosol chamber and which is inserted into a suitably shaped recess or cavity <NUM> in a power component <NUM> in order to bring the susceptor into the working range of an induction work coil <NUM>. The atomiser, inside the enclosure, is inserted into the open space inside a helical coil.

The enclosure performs a number of functions. It defines the aerosol chamber around the atomiser. If it is closed at the base, it can collect any free liquid that has not been vaporised or which has condensed out of the generated aerosol, and hence reduce leakage out of the cartomiser. Also, it protects the atomiser, which in its cantilevered position, extending outwardly from the space occupied by the reservoir, is potentially vulnerable to damage when the cartomiser is separated from the power component. However, the enclosure is not essential, and the cantilevered atomiser can be implemented without an enclosure.

<FIG> shows a highly simplified schematic cross-sectional side view of part of a vapour generation system with a cantilevered atomiser and lacking an aerosol chamber enclosure which is part of the cartomiser portion. As before, the atomiser <NUM> is supported in a cantilevered fashion by a socket <NUM> formed in a component at the base of a reservoir <NUM> of a cartomiser <NUM> (alternatively, the system may be configured as a unitary device in which the cartomiser part is configured as an aerosol generation part which is not separable from the rest of the system). A power component <NUM> has a recess <NUM> which houses a work coil <NUM> with a helical shape arranged with its longitudinal axis along the direction of the atomiser <NUM>. The cantilevered portion of the atomiser <NUM>, including at least part of the susceptor (not shown specifically), is inserted into the recess <NUM> so that the susceptor is located inside the helix of the work coil <NUM> for induction heating when alternating current is passed through the coil <NUM>. The recess <NUM> and the coil <NUM> cooperate to form an aerosol chamber around the atomiser <NUM>. The coil <NUM> can be in close proximity to the susceptor, and there are no intervening parts between the coil and the susceptor, so the efficiency of the induction heating can be maximised.

<FIG> shows a highly simplified schematic cross-sectional side view of part of a vapour generation system according to another example. As in <FIG>, there is no enclosure around the cantilevered susceptor <NUM> comprised in the cartomiser portion <NUM>. This design differs from the <FIG> arrangement in that the coil <NUM> is located inside a housing of the power component <NUM> (which may or may not be separable from the parts of the cartomiser component) so as to surround the recess <NUM>, rather than being located inside the recess. Hence, the coil <NUM> and the susceptor are separated by the material of the housing (which need not be thick) so the efficiency may be somewhat reduced compared to the <FIG> example, but the coil is protected from any leakage of liquid.

Claim 1:
An aerosol source for an electronic vapour provision system (<NUM>), comprising:
a reservoir housing (<NUM>) defining a reservoir (<NUM>) for holding aerosolisable substrate material; and
an elongate atomiser (<NUM>) to which aerosolisable substrate material from the reservoir is deliverable for vaporisation, the atomiser having a porosity and comprising a susceptor for induction heating, and having a first end and a second end, the atomiser mounted at one of its ends only so as to be supported at the mounted end in a cantilevered arrangement having an unsupported cantilever portion, such that the susceptor extends outwardly with respect to an exterior boundary of the reservoir housing.