Patent Description:
The popularity and use of reduced-risk or modified-risk devices (also known as vaporisers) has grown rapidly in the past few years as an aid to assist habitual smokers wishing to quit using traditional tobacco products such as cigarettes, cigars, cigarillos, and rolling tobacco. Various devices and systems are available that heat or warm aerosolisable substances as opposed to burning tobacco in conventional tobacco products.

A commonly available reduced-risk or modified-risk device is the heated substrate aerosol generation device or heat-not-burn (HNB) device. Devices of this type generate an aerosol or vapour by heating an aerosol substrate (i.e. consumable) that typically comprises moist leaf tobacco or other suitable aerosolisable material to a temperature typically in the range <NUM> to <NUM>. Heating an aerosol substrate, but not combusting or burning it, releases an aerosol that comprises the components sought by the user but not the toxic and carcinogenic by-products of combustion and burning. In addition, the aerosol produced by heating the tobacco or other aerosolisable material does not typically comprise the burnt or bitter taste that may result from combustion that can be unpleasant for the user.

However, within such devices, the aerosol substrate is known to lose structural integrity during the heating process and may shrink and/or begin to release aerosolisable material. This may result in inconsistent heating of the aerosol substrate and adversely affect the aerosol generating properties of the device.

Furthermore, if a user removes the aerosol substrate from the device during the heating operation, there is a risk of the user contacting a hot portion of the aerosol substrate.

Therefore, an object of the present invention is to address one or more of these issues.

<CIT> describes an aerosol generating device. The aerosol generating device comprises a shell, wherein the shell is provided with an accommodating cavity for accommodating an aerosol generation product, and a device electrode which is arranged in the accommodating cavity; and the device electrode is configured to perform magnetic adsorption and contact with the aerosol generation product arranged in the accommodating cavity, so that a power-on heating element in the aerosol generation product is electrically connected with the device electrode.

According to a first aspect, the present disclosure provides a heating chamber for an aerosol generation device, the heating chamber comprising: a compression element comprising a thermally active material; and a reaction surface, wherein the heating chamber is adapted to receive an aerosol substrate between the compression element and the reaction surface, and the compression element is configured to compress the aerosol substrate against the reaction surface, wherein the compression element is configured to undergo displacement according to a temperature of the heating chamber and a thermal response characteristic of a magnetic property of the thermally active material.

Applying compression to the aerosol substrate according to a temperature of the heating chamber enables consistent heating and enables preventing the aerosol substrate from being removed while hot. Additionally, compression of an aerosol substrate while it is heated improves aerosol generation. Furthermore, the thermal response characteristic of the magnetic property is a passive response, and does not require control circuitry to control the displacement.

The heating chamber further comprises a magnetic interaction element comprising a first magnetic material, wherein: the thermally active material comprises a second magnetic material, the compression element is displaced in response to a change in a magnetic force between the first and second magnetic materials, at least one of the first and second magnetic materials has a threshold temperature at which the material undergoes a magnetic phase transition, and the heating chamber is configured to, during aerosol generation, raise the temperature of the heating chamber to an aerosol generation temperature above the threshold temperature. By providing a magnetic interaction element configured to interact with the thermally active material, and by designing the thermally active material to undergo a magnetic phase transition, the compression element can be configured to clearly move between an open position at which the aerosol substrate can be removed from the heating chamber and a closed position at which a compression force is applied to hold the aerosol substrate.

Optionally, the heating chamber further comprises a heating element arranged on or behind, or comprised within, the compression element. Optionally, the heating chamber further comprises a heating element arranged on or behind, or comprised within, the reaction surface. By providing a heating element on, behind or within the compression element and/or the reaction surface, the heating element remains close to the aerosol substrate throughout any displacement and compression, further improving consistency of heating.

Optionally, the reaction surface is a second compression element configured to undergo displacement according to a temperature of the heating chamber. By providing compression by two opposing elements, uniformity of compression in the aerosol substrate can be improved. Additionally, a range of motion for each compression element can be halved compared to the single compression element example. With a reduced range of motion, a thermally active material with reduced maximum magnetic field strength can be used, or a quantity of the thermally active material can be reduced.

Optionally, the compression element is arranged between the magnetic interaction element and the reaction surface, one of the first and second magnetic materials is ferromagnetic up to a Curie temperature lower than the aerosol generation temperature, and the other of the first and second magnetic materials is paramagnetic above the Curie temperature. In this configuration, a magnetic force holds the compression element open in a low temperature state (below the Curie temperature), and the compression element does not inhibit adding or removing the aerosol substrate in the low temperature state.

Optionally, the magnetic interaction element is arranged on or behind, or comprised in, the reaction surface, and one of the first and second magnetic materials is antiferromagnetic up to a Néel temperature lower than the aerosol generation temperature, and the other of the first and second magnetic materials is ferromagnetic at the aerosol generation temperature. In this configuration, a magnetic force holds the compression element closed in a high temperature state (above the Néel temperature).

Optionally, the magnetic interaction element is arranged on or behind, or comprised in, the reaction surface, and one of the first and second magnetic materials is ferromagnetic up to a Curie temperature lower than the aerosol generation temperature, and the other of the first and second magnetic materials is diamagnetic. In this configuration, a magnetic force holds the compression element open in a low temperature state (below the Curie temperature).

Optionally, the heating chamber further comprises a resilient element configured to bias the compression element towards or away from the reaction surface. The resilient element can be configured to oppose a force applied due to the magnetic property of the thermally active material, in order to bias the compression element in two different directions depending on the temperature in the heating chamber.

According to a second aspect, the present disclosure provides an aerosol generation device comprising a heating chamber as described above.

According to a third aspect, the present disclosure provides an aerosol generation system comprising a heating chamber as described above and an aerosol substrate arranged between the compression element and the reaction surface.

According to a fourth aspect, the present disclosure provides a method of generating an aerosol comprising: providing an aerosol substrate between the compression element and the reaction surface of a heating chamber as described above; operating the heating chamber to raise a temperature of the heating chamber to an aerosol generation temperature; extracting an aerosol from the heating chamber; operating the heating chamber to lower a temperature of the heating chamber to an aerosol substrate release temperature; and removing the aerosol substrate from the heating chamber.

<FIG> is a schematic cross-section of an aerosol generation device incorporating a heating chamber according to the present disclosure.

The aerosol generation device <NUM> comprises the heating chamber <NUM>, an electrical power supply <NUM> and control circuitry <NUM>. The control circuitry <NUM> controls supply of electrical power from the supply <NUM> to the heating chamber <NUM> in order to heat a consumable <NUM> that has been received in the heating chamber <NUM>.

The heating chamber <NUM> comprises a compression element <NUM> and a reaction surface <NUM>. The consumable <NUM> is received between the compression element <NUM> and the reaction surface <NUM>, and the compression element <NUM> is configured to undergo displacement in order to compress the consumable <NUM> against the reaction surface <NUM>.

Specifically, the consumable comprises at least an aerosol substrate <NUM> which is arranged in the heating chamber <NUM> for aerosol generation. The consumable may, for example, take the form of a cigarette in which the aerosol substrate is contained in a wrapper. The cigarette may additionally comprise a mouthpiece <NUM> comprising a filter. In this configuration, the aerosol substrate <NUM> is heated to generate an aerosol, and a user may inhale the aerosol through the mouthpiece <NUM>.

In order to facilitate inhaling of the aerosol, the aerosol generation device may comprise an air flow channel with an inlet and outlet at different points on a housing of the aerosol generation device, where the air flow channel extends through the heating chamber <NUM>.

In particular, the aerosol generation device may comprise an opening which is capable of receiving the consumable <NUM> and which is also configured as the outlet for the air flow channel. In embodiments where the consumable <NUM> does not include a mouthpiece <NUM>, the aerosol generation device may comprise a mouthpiece which is combined with or separate from an opening for inserting the consumable <NUM> into the heating chamber <NUM>. For example, the opening for inserting the consumable <NUM> may have a lid which includes the mouthpiece.

The electrical power supply <NUM> may, for example, be a battery or may be a connection to an external power supply.

The control circuitry <NUM> may comprise general-purpose programmable circuitry or hard coded logic circuitry for controlling the heating chamber <NUM>.

The control circuitry <NUM> may also comprise a temperature sensor for determining a temperature of the heating chamber <NUM>. Alternatively the control circuitry <NUM> may estimate the temperature of the heating chamber <NUM> based on how it has recently controlled the heating chamber <NUM>.

The control circuitry <NUM> may also comprise a user interface such as a button or slider for activating aerosol generation in the heating chamber or for controlling properties of the aerosol generation such as a time length of an aerosol generating session, or a temperature profile of how quickly the consumable <NUM> is heated or a peak temperature to which the consumable <NUM> is heated.

In use, the aerosol generation device <NUM> may be operated by:.

In embodiments of the invention, the compression element <NUM> comprises a thermally active material configured such that at least part of the displacement of the compression element <NUM> occurs passively, according to a temperature of the heating chamber <NUM> and a thermal response characteristic of the thermally active material. In some embodiment, this passive displacement may be combined with an actively-controlled displacement such as a displacement driven by an actuator, although this is not essential.

In particular, the compression element <NUM> comprises a material which undergoes a change in a magnetic property in dependence upon a temperature of the material. For example, as will be shown with reference to specific embodiments, this change in magnetic property may be a phase transition from between two types of magnetic behaviour including ferromagnetic, paramagnetic, antiferromagnetic and diamagnetic behaviour. In the present description, "ferromagnetic" includes both ferromagnetic and ferromagnetic behaviour. Alternatively (although less preferably) the change in magnetic property may be a continuous variation in field strength without a phase transition. A phase transition is preferable because the transition can provide a relatively high instantaneous force so that displacement of the compression element can overcome, for example, friction or any stickiness associated with by-products of aerosol generation.

<FIG> and <FIG> are schematic cross-sections of the heating chamber <NUM> showing additional detail of the compression element <NUM> and the reaction surface <NUM> in a first embodiment. The cross-section extends in a plane looking along a "long" direction of the consumable <NUM> as shown in <FIG>.

In the first embodiment, the compression element <NUM> interacts magnetically with a magnetic interaction element <NUM>. The magnetic interaction element <NUM> may for example be one or more portions of a first magnetic material that is attached to the interior of the heating chamber <NUM>, such that the compression element <NUM> is arranged between the magnetic interaction element <NUM> and the reaction surface <NUM>.

In this configuration, the thermally active material of the compression element <NUM> comprises a second magnetic material which may be the same as or different from the first magnetic material of the magnetic interaction element <NUM>. During an aerosol generation session, a temperature of the heating chamber <NUM> is raised to an aerosol generation temperature at which aerosol is generated from the consumable <NUM>. When the temperature in the heating chamber <NUM> rises during the aerosol generation session, at least one of the first and second magnetic materials undergoes a change in magnetic property, and a force of the interaction between the compression element <NUM> and the magnetic interaction <NUM> changes.

In the specific configuration of the first embodiment, when the heating chamber <NUM> is in a low temperature state illustrated in <FIG>, at least one of the first and second magnetic materials is ferromagnetic while the other of the first and second magnetic materials may be ferromagnetic or paramagnetic. As a result, the compression element <NUM> and the magnetic interaction element <NUM> experience an attractive force which biases the compression element <NUM> away from the reaction surface <NUM>.

On the other hand, when the heating chamber <NUM> is in a high temperature state at the aerosol generation chamber, as illustrated in <FIG>, the first and second magnetic materials are both paramagnetic, and there is no significant attractive force between the compression <NUM> and the magnetic interaction element <NUM>. In order to achieve this, the magnetic materials must be chosen such that, if they have a paramagnetic temperature range, the upper limit of this range (Curie temperature) is lower than the aerosol generation temperature.

When the heating chamber <NUM> cools down to below the Curie temperature (the aerosol substrate release temperature), the magnetic properties return to their low temperature states, and the compression element <NUM> and magnetic interaction element <NUM> again experience an attractive force to return the compression element <NUM> to an open position at which the consumable <NUM> can be inserted and removed.

As further illustrated in <FIG> and <FIG>, a second force is be applied in order to cause displacement of the compression element <NUM> when the magnetic interaction is eliminated at high temperature above the Curie temperature. For example, a resilient element <NUM> (such as a spring) may be arranged adjacent to the magnetic interaction element <NUM> to provide a force opposed to the attraction between the magnetic interaction element <NUM> and the compression element <NUM>, biasing the compression element <NUM> away from the reaction surface <NUM>. When the magnetic attraction is removed, the resilient element <NUM> displaces the compression element <NUM> towards the reaction surface <NUM>, causing compression of the aerosol substrate <NUM>.

As further shown in <FIG> and <FIG>, one or more heating elements <NUM> may be provided to supply heat into the chamber <NUM>. The heating elements <NUM> may be any known type of heating element such as a combustible heating element or an electronic resistive heating element.

The heating element(s) <NUM> may be arranged in various positions around the heating chamber <NUM>. For example, a heating element <NUM> may be arranged at the compression element <NUM> (either on a surface or comprised within the compression element <NUM>). In this case, because the compression element <NUM> is configured to undergo displacement, it may be necessary to provide a flexible or sliding fuel/power supply to the heating element <NUM>. However, because the compression element <NUM> is configured to compress the aerosol substrate <NUM>, this positioning may have the benefit of improved thermal contact and more efficient heating of the substrate.

Alternatively or additionally, a heating element <NUM> may be provided in a fixed position such as a wall of the heating chamber, for example behind the compression element <NUM> (i.e. with the compression element between the heating element and the reaction surface), or at the reaction surface <NUM> (either located on the reaction surface <NUM> or embedded within the reaction surface <NUM>).

<FIG> illustrates a second embodiment of the heating chamber <NUM> as a variant of the first embodiment shown in <FIG> and <FIG>. The second embodiment differs from the first embodiment in that the reaction surface is not a fixed surface, and is also configured to undergo displacement similar to that previously described for the compression element. In other words, the reaction surface <NUM> can be configured as a second compression element configured to undergo displacement according to the temperature of the heating chamber. In a simple case, the heating chamber <NUM> is substantially symmetric with the displacement of the second compression element <NUM> being configured to function in the same way as the first compression element <NUM>.

More generally, the number of compression elements is not limited. For example, the chamber <NUM> may have a triangular configuration arranged to receive a consumable <NUM> between three compression elements arranged at <NUM> degree intervals around the consumable <NUM>. In this case, the "reaction surface" function for each compression element is split between the other two compression elements.

<FIG> illustrates an alternative arrangement in a third embodiment, as a variant of the first embodiment.

In the third embodiment, the magnetic interaction element <NUM> is arranged to face the compression element <NUM> across the heating chamber <NUM> such that the consumable <NUM> is received between the magnetic interaction element <NUM> and the compression element <NUM>. The magnetic interaction element <NUM> in this case may be located adjacent to or combined with the reaction surface <NUM> (e.g. located on, within, or behind the reaction surface).

In the third embodiment, multiple types of magnetic configuration can be used.

In a first case, the compression element <NUM> and magnetic interaction element <NUM> can be configured to experience no magnetic force at low temperatures and to experience an attractive magnetic force at the aerosol generation temperature. This can be achieved by using a magnetic material that is antiferromagnetic at temperatures below a Néel temperature lower than the aerosol generation temperature in one of the compression element <NUM> and the magnetic interaction element <NUM>, and by using a magnetic material that is ferromagnetic at the aerosol generation temperature in the other of the compression element <NUM> and the magnetic interaction element <NUM>.

At the same time, in the first case, the resilient element <NUM> may be configured to bias the compression element <NUM> towards the open position in which the consumable <NUM> is released. As such, when the heating chamber <NUM> is at a low temperature (e.g. close to room temperature) the consumable <NUM> can be inserted and removed. Alternatively, since there is no magnetic force at low temperatures in this configuration, the resilient element <NUM> may be omitted, and it may be left to a user of the aerosol generation device to exert a minimal force to move the compression element <NUM> to an open position where the consumable <NUM> can be inserted and removed.

In a second case, the compression element <NUM> and magnetic interaction element <NUM> can be configured to experience a repulsive magnetic force at low temperatures, and to experience no magnetic force at the aerosol generation temperature.

This can be achieved by arranging two ferromagnetic materials to oppose each other in a repulsive configuration. More specifically, the compression element <NUM> can be arranged with a magnetic field aligned along a first direction and the magnetic interaction element <NUM> can be arranged with a magnetic field aligned along the reverse of the first direction. Provided that at least one of the first magnetic material used in the magnetic interaction element <NUM> and the second magnetic material used in the compression element <NUM> has a Curie temperature lower than the aerosol generation temperature, then the repulsive magnetic force is not present when the heating chamber <NUM> is at the aerosol generation temperature.

Alternatively, and more preferably, the second case can be achieved by using a ferromagnetic material and a strongly diamagnetic material, such that it is not necessary to align the fields. More specifically, a diamagnetic material will generate an opposing field regardless of an orientation of the magnetic field of the ferromagnetic material, and the ferromagnetic and diamagnetic materials will repel each other. Provided that the ferromagnetic material has a Curie temperature lower than the aerosol generation temperature, the repulsive force will not be present at the aerosol generation temperature.

In the second case, the resilient element <NUM> may be configured as in the first embodiment, with a bias to displace the compression element <NUM> toward the reaction surface <NUM>.

<FIG> is a schematic cross-section of an alternative aerosol generation device <NUM> that has received a consumable <NUM>. The aerosol generation device <NUM> and consumable <NUM> are largely similar to the features described with reference to <FIG>, and only the differences are described here.

In <FIG>, an air flow channel extends through the aerosol generation device <NUM> between an inlet and a separate outlet. However, as shown in <FIG>, the inlet and outlet of the air flow channel may instead be a same point on the housing of the aerosol generation device, and the heating chamber <NUM> may have a pot-type configuration with only one opening. In this configuration, air is drawn into the aerosol substrate <NUM> through one part of the opening and drawn out of the aerosol substrate <NUM> through another part of the opening.

This difference in the air flow channel may require a change to the heating chamber <NUM> as illustrated in <FIG>.

More specifically, as shown in <FIG>, the heating chamber <NUM> may comprise one or more protrusions <NUM> configured to maintain a space between the consumable <NUM> and a wall of the heating chamber <NUM> so that air can flow around the consumable <NUM>. The protrusions may for example be ribs extending along the heating chamber <NUM>. The protrusion(s) <NUM> must be configured to avoid interfering with the displacement of the compression element <NUM>. Nevertheless, the protrusion(s) <NUM> may provide a synergistic benefit of assisting with compression by restricting the cross-section of the heating chamber <NUM> available for the consumable <NUM> to occupy.

Claim 1:
A heating chamber for an aerosol generation device, the heating chamber comprising:
a compression element (<NUM>) comprising a thermally active material; and
a reaction surface (<NUM>),
wherein the heating chamber (<NUM>) is adapted to receive an aerosol substrate (<NUM>) between the compression element and the reaction surface, and the compression element is configured to compress the aerosol substrate against the reaction surface,
wherein the compression element is configured to undergo displacement according to a temperature of the heating chamber and a thermal response characteristic of a magnetic property of the thermally active material.
the heating chamber further comprising a magnetic interaction element (<NUM>) comprising a first magnetic material, wherein:
the thermally active material comprises a second magnetic material,
the compression element (<NUM>) is displaced in response to a change in a magnetic force between the first and second magnetic materials,
at least one of the first and second magnetic materials has a threshold temperature at which the material undergoes a magnetic phase transition, and
the heating chamber is configured to, during aerosol generation, raise the temperature of the heating chamber to an aerosol generation temperature above the threshold temperature.