Patent Description:
Devices which heat, rather than burn, an aerosol generating material to produce an aerosol for inhalation have become popular with consumers in recent years. Such devices can use one of a number of different approaches to provide heat to the aerosol generating material.

One approach is to provide an aerosol generating device which employs a resistive heating system. In such a device, a resistive heating element is provided to heat aerosol generating material positioned within a cavity of the device and thereby generate a vapour which typically cools and condenses to form an aerosol for inhalation by a user of the device.

The resistive heating system can be an internal resistive heating system in which one or more resistive heating elements (e.g. a heating blade arranged within the cavity of the device) are arranged to be positioned within the aerosol generating material during use of the aerosol generating device and/or an external resistive heating system in which one or more resistive heating elements are arranged to at least partially surround the aerosol generating material. The use of an internal resistive heating system may be preferred because the heating process is generally more efficient and requires a lower power input due to the fact that most of the heat is transferred directly from the heating element to the aerosol generating material, with minimal heat transfer to other components.

It would be desirable to provide an aerosol generating device and an aerosol generating system which has a reduced power requirement and/or which provides improved control over the heating of the aerosol generating material.

<CIT> describes a multi-stage temperature control method for a heat-not-burn system. A base plate is included, a third heating needle is arranged on the base plate, and heating modes of a first heating needle, a second heating needle and the third heating needle are controlled by a circuit board respectively; the first heating needle, the second heating needle, and the third heating needle are inserted into a first section, a second section and a third section of a cigarette, and the first heating needle, the second heating needle, and the third heating needle heat the first section, the second section and the third section respectively and sequentially and then heat the cigarette together.

<CIT> describes a peripheral penetrative heating device for heat-not-burn cigarettes. The peripheral penetrative heating device comprises a hollow device; a heating cavity for holding a heating material is arranged in the hollow device; the heating cavity includes an outer heat-insulating layer, a penetrating rod with a sliding end, a spring, and a base with a fixing barrel; the inner wall of the outer heat-insulating layer is provided with a nick for expanding the penetrating rod by means of etching, and the nick is used for adjusting the position of a top rod.

According to a first aspect of the present disclosure, there is provided an aerosol generating device as set out in claim <NUM>.

The aerosol generating device is adapted to heat the aerosol generating material, without burning the aerosol generating material, to volatise at least one component of the aerosol generating material and thereby generate a vapour which cools and condenses to form an aerosol for inhalation by a user of the aerosol generating system/device.

In general terms, a vapour is a substance in the gas phase at a temperature lower than its critical temperature, which means that the vapour can be condensed to a liquid by increasing its pressure without reducing the temperature, whereas an aerosol is a suspension of fine solid particles or liquid droplets, in air or another gas. It should, however, be noted that the terms 'aerosol' and 'vapour' may be used interchangeably in this specification, particularly with regard to the form of the inhalable medium that is generated for inhalation by a user.

The provision of a plurality of heating circuits which can be independently supplied with electrical energy from the power source allows the heating circuits to be selectively energised. This allows different portions of the aerosol generating material to be selectively heated to generate an aerosol with suitable characteristics for inhalation by a user and avoids the need to simultaneously heat all of the aerosol generating material in the cavity. This in turn reduces the time taken to heat the aerosol generating material and, thus, improves the energy efficiency of the aerosol generating device. In addition, aerosol generating material can easily be positioned in the cavity when the electrical circuit components are in the first position, whilst movement of the electrical circuit components to the second position may advantageously help to retain the aerosol generating material in the cavity.

Each pair of electrical contacts is movable between a first position in which the pair of electrical contacts does not extend into the cavity and a second position in which the pair of electrical contacts extends into the cavity and into a portion of the aerosol generating material. Such an arrangement may facilitate insertion of aerosol generating material into the cavity, by ensuring that the electrical contacts do not extend into the cavity when in the first position.

The pairs of electrical contacts may be simultaneously or sequentially movable between the first and second positions. Movement of the electrical contacts is thus achieved in a simple manner.

The controller may be configured to control the power source to sequentially supply electrical energy to one or more of the heating circuits when the pairs of electrical contacts are in the second position. Such an arrangement allows different portions or regions of the aerosol generating material to be heated sequentially, thereby further improving energy efficiency and providing for generation of an aerosol with optimum characteristics.

The cavity may be an elongate cavity having a longitudinal axis and the pairs of electrical contacts may be spaced along the longitudinal axis. Such an arrangement may facilitate positioning of aerosol generating material in the cavity and/or optimal heating of aerosol generating material positioned in the cavity.

The aerosol generating device may comprise a positioning mechanism configured to move the pairs of electrical contacts between the first position and the second position in a direction substantially orthogonal to the longitudinal axis. Movement of the electrical contacts may, therefore, be achieved with relative ease.

The positioning mechanism may be arranged for simultaneously moving the pairs of electrical contacts from the first position to the second position. In this mode, the positioning mechanism may comprise a radially movable pusher. The radially movable pusher may be manually activated by a user.

In an alternative, the positioning mechanism may be arranged for sequentially moving the pairs of electrical contacts from the first position to the second position. In this mode, the positioning mechanism may comprise an axially movable pusher. The axially movable pusher may be manually activated by a user.

The electrical contacts may be spaced from a heating element positioned in the aerosol generating material when the electrical contacts are in the first position and may be arranged to contact the heating element at different locations when the electrical contacts are in the second position. The contact between the electrical contacts and the heating element at different locations allows different sections of the heating element to be selectively heated. This in turn allows different portions or regions of the aerosol generating material to be selectively heated.

The heating element may be mounted on the housing and may project into the cavity. With such an arrangement, the heating element is a component part of the aerosol generating device. Thus, the manufacture of an aerosol generating article, e.g., comprising the aerosol generating material, for use with the aerosol generating device may be simplified.

The heating element may alternatively be provided with the aerosol generating material, for example in the form of an aerosol generating article comprising an aerosol generating material and a heating element positioned in the aerosol generating material. With such an arrangement, the heating element forms part of the consumable element, i.e., the aerosol generating article. This may lead to a further improvement in heating efficiency and may simplify the structure of the aerosol generating device by avoiding the need to provide a heating element that is a component part of the device. This may in turn avoid the need for cleaning and/or replacement of the heating element.

The heating element may comprise a resistive heating element. The heating element may comprise an electrically resistive material. Examples of suitable electrically resistive materials include, but are not limited to, metals, metal alloys, electrically conductive ceramics, for example tungsten and alloys thereof, and composite materials comprising a metallic material and a ceramic material.

According to a second aspect of the present disclosure, there is provided an aerosol generating system comprising an aerosol generating device as defined above and an aerosol generating article positioned in the cavity, wherein the aerosol generating article comprises an aerosol generating material and a heating element positioned in the aerosol generating material.

As noted above, with such an arrangement, the heating element forms part of the consumable element, i.e., the aerosol generating article. This may simplify the structure of the aerosol generating device by avoiding the need to provide a heating element that is a component part of the device. The need for cleaning and/or replacement of the heating element is thereby eliminated.

The aerosol generating article may comprise an aerosol generating material circumscribed by a paper wrapper. The aerosol generating article may be formed substantially in the shape of a stick. The aerosol generating article may include a filter, for example comprising cellulose acetate fibres. The filter may be in abutting coaxial alignment with the aerosol generating material. Alternatively, the aerosol generating article may be formed substantially in the shape of a disc or plate.

The aerosol generating material may be any type of solid or semi-solid material. Example types of aerosol generating solids include powder, granules, pellets, shreds, strands, particles, gel, strips, loose leaves, cut leaves, cut filler, porous material, foam material or sheets. The aerosol generating material may comprise plant derived material and in particular, may comprise tobacco. It may advantageously comprise reconstituted tobacco.

The aerosol generating material may comprise an aerosol-former. Examples of aerosol-formers include polyhydric alcohols and mixtures thereof such as glycerine or propylene glycol. Typically, the aerosol generating material may comprise an aerosol-former content of between approximately <NUM>% and approximately <NUM>% on a dry weight basis. In some embodiments, the aerosol generating material may comprise an aerosol-former content of between approximately <NUM>% and approximately <NUM>% on a dry weight basis, and possibly approximately <NUM>% on a dry weight basis.

Upon heating, the aerosol generating material may release volatile compounds. The volatile compounds may include nicotine or flavour compounds such as tobacco flavouring.

Referring initially to <FIG>, there is shown diagrammatically a first example of an aerosol generating system <NUM>. The aerosol generating system <NUM> comprises an aerosol generating device <NUM> and a first example of an aerosol generating article <NUM>. The aerosol generating device <NUM> has a proximal end <NUM> and a distal end <NUM> and comprises a housing <NUM> which defines a cavity <NUM>. The housing <NUM> includes one or more air inlets <NUM> for supplying air to the cavity <NUM>. The aerosol generating device <NUM> further includes a power source <NUM> and a controller <NUM>. The power source <NUM> typically comprises one or more batteries which could, for example, be inductively rechargeable.

The aerosol generating device <NUM> is generally cylindrical and the cavity <NUM> defined by the housing <NUM> is also cylindrical and takes the form of a cylindrical heating compartment. The cavity <NUM> is arranged to receive a correspondingly shaped generally cylindrical or rod-shaped aerosol generating article <NUM> comprising an aerosol generating material <NUM> and a resistive heating element <NUM> positioned in the aerosol generating material <NUM>. The resistive heating element <NUM> is an elongate heating element <NUM> and extends in the longitudinal direction through the aerosol generating material <NUM>. In the example illustrated in <FIG>, the resistive heating element <NUM> is positioned in the aerosol generating material <NUM> during manufacture of the aerosol generating article <NUM>. In an alternative example not illustrated in the drawings, the resistive heating element <NUM> could be mounted on the housing <NUM> so that it projects into the cavity <NUM> and so that it is inserted into the aerosol generating material <NUM> during insertion of an aerosol generating article <NUM> (without an integral heating element <NUM>) into the cavity <NUM> by a user. For example, the heating element <NUM> could be a blade or elongate pin which enters the aerosol generating material <NUM> as the aerosol generating material <NUM> is placed in the cavity <NUM>.

The aerosol generating article <NUM> is a disposable article which may, for example, contain tobacco as the aerosol generating material <NUM>. The aerosol generating article <NUM> has first and second ends <NUM>, <NUM> and comprises a paper wrapper <NUM> surrounding the aerosol generating material <NUM>. The aerosol generating article <NUM> also comprises a filter <NUM> at the first end <NUM> which is in abutting coaxial alignment with the aerosol generating material <NUM> and the paper wrapper <NUM>. The filter <NUM> acts as a mouthpiece and comprises an air-permeable plug, for example comprising cellulose acetate fibres. Both the paper wrapper <NUM> and the filter <NUM> are overwrapped by an outer wrapper <NUM> typically comprising tipping paper. In an alternative example not illustrated in the drawings, the filter <NUM> could be omitted and instead the aerosol generating device <NUM> could include an integrated mouthpiece.

The aerosol generating device <NUM> comprises a plurality of heating circuits 40a-e for heating the aerosol generating material <NUM>. The heating circuits 40a-e are electrically connected to the power source <NUM> and the controller <NUM>, although the electrical connections are not shown in the drawings for simplicity.

In the illustrated first example, each heating circuit 40a-e comprises an electrical circuit component in the form of a pair of electrical contacts 42a-e. The pairs of electrical contacts 42a-e are movable between a first position shown in <FIG>, in which the electrical contacts 42a-e do not extend into the aerosol generating material <NUM> of the aerosol generating article <NUM> positioned in the cavity <NUM>, and a second position shown in <FIG>, in which the electrical contacts 42a-e extend into the aerosol generating material <NUM>. As will be apparent from a comparison of <FIG>, when the pairs of electrical contacts 42a-e are in the first position, the electrical contacts 42a-e are spaced from the heating element <NUM> of the aerosol generating article <NUM>, whereas the electrical contacts 42a-e are arranged to contact the heating element <NUM> when they are in the second position.

The controller <NUM> is configured to control the power source <NUM> to independently supply electrical energy to one or more of the heating circuits 40a-e, and more particularly to sequentially supply electrical energy to one or more pairs of electrical contacts 42a-e. In more detail and in one mode, the controller <NUM> includes control circuitry which is configured to control the power source <NUM> to supply electrical energy to the first pair of electrical contacts 42a. The heating element <NUM> is thereby heated in the region designated A in <FIG> so that a first portion of the aerosol generating material <NUM> proximate the heated region A of the heating element <NUM> is heated by heat transferred from the heated region A.

The controller <NUM> may be configured to detect the consumption of the first portion of the aerosol generating material <NUM>, e.g., by detecting the number of inhalations or 'puffs' by a user of the aerosol generating device <NUM> or by detecting that a predetermined period of time has elapsed. After detecting a predetermined number of puffs or after detecting that a predetermined period of time has elapsed, the controller <NUM> may be configured to decrease the supply of electrical energy to the first pair of electrical contacts 42a and to simultaneously increase the supply of electrical energy to the second pair of electrical contacts 42b, until such time as the energy supply to the first pair of electrical contacts 42a ceases and the energy supply to the second pair of electrical contacts 42b reaches a maximum level. As a consequence, the heating element <NUM> is now heated in the region designated B in <FIG> so that a second portion of the aerosol generating material <NUM> proximate the heated region B of the heating element <NUM> is heated by heat transferred from the heated region B.

After detecting a predetermined number of puffs or after detecting that a predetermined period of time has elapsed, the controller <NUM> may be configured to decrease the supply of electrical energy to the second pair of electrical contacts 42b and to simultaneously increase the supply of electrical energy to the third pair of electrical contacts 42c, until such time as the energy supply to the second pair of electrical contacts 42b ceases and the energy supply to the third pair of electrical contacts 42c reaches a maximum level. As a consequence, the heating element <NUM> is now heated in the region designated C in <FIG> so that a third portion of the aerosol generating material <NUM> proximate the heated region C of the heating element <NUM> is heated by heat transferred from the heated region C.

The controller <NUM> continues to implement the methodology described above so that electrical energy is sequentially supplied by the power source <NUM> to the fourth and fifth pairs of electrical contacts 42d, 42e, thereby causing the heating element <NUM> to be sequentially heated in the regions designated D and E in <FIG> so that fourth and fifth portions of the aerosol generating material <NUM> are sequentially heated.

After detecting a predetermined number of puffs or after detecting that a predetermined period of time has elapsed during the supply of electrical energy to the fifth pair of electrical contacts 42e, the controller <NUM> decreases the supply of electrical energy to the fifth pair of electrical contacts 42e until the electrical energy supplied to the electrical contacts 42e ceases. At this point, no further heating of the aerosol generating material <NUM> takes place and the controller <NUM> may be configured to prevent the supply of electrical energy from the power source <NUM> to the pairs of electrical contacts 42a-e until the used aerosol generating article <NUM> has been removed from the cavity <NUM> and a replacement aerosol generating article <NUM>, containing previously unheated aerosol generating material <NUM>, has been inserted into the cavity <NUM>.

In another mode, two or more of the heating circuits 40a-e may be supplied with electrical energy at the same time to simultaneously heat two or more portions of the aerosol generating material <NUM>. For example, the methodology can consist of supplying electrical energy to the pair of heating circuits 40a, 40b to simultaneously heat two regions A and B of the heating element <NUM>, and hence to heat the corresponding portions of the aerosol generating material <NUM>, while the other heating circuits 40c-40e remain unelectrified. The heating operation can be continued for heating the other regions C, D, E of the heating element <NUM> with the heating circuits 40c-e, either individually or in pairs or groups.

Referring now to <FIG>, there is shown diagrammatically a second example of an aerosol generating system <NUM> which is similar to the first example of the aerosol generating system <NUM> described above and in which corresponding components are identified using the same reference numerals.

The aerosol generating system <NUM> comprises an aerosol generating device <NUM> comprising a plurality of heating circuits 40a-e for heating the aerosol generating material <NUM>. In the illustrated second example, each heating circuit 40a-e comprises a heating element 52a-e. The heating elements 52a-e can be simultaneously movable between a first position shown in <FIG>, in which the heating elements 52a-e do not extend into the aerosol generating material <NUM> of the aerosol generating article <NUM> positioned in the cavity <NUM>, and a second position shown in <FIG>, in which the heating elements 52a-e extend into the aerosol generating material <NUM>. Note that in the second example illustrated in <FIG>, the aerosol generating article <NUM> does not include an integral heating element <NUM>.

The controller <NUM> is configured to control the power source <NUM> to supply electrical energy to one or more of the heating circuits 40a-e, and in some embodiments to sequentially supply electrical energy to each of the heating elements 52a-e. In more detail and in one mode, the controller <NUM> includes control circuitry which is configured to control the power source <NUM> to supply electrical energy to the first heating element 52a. The heat transferred from the first heating element 52a thereby heats a first portion of the aerosol generating material <NUM> in the region designated A in <FIG>.

After detecting a predetermined number of puffs or after detecting that a predetermined period of time has elapsed, the controller <NUM> may be configured to decrease the supply of electrical energy to the first heating element 52a and to simultaneously increase the supply of electrical energy to the second heating element 52b, until such time as the energy supply to the first heating element 52a ceases and the energy supply to the second heating element 52b reaches a maximum level. As a consequence, a second portion of the aerosol generating material <NUM> is now heated in the region designated B in <FIG> by heat transferred from the second heating element 52b.

After detecting a predetermined number of puffs or after detecting that a predetermined period of time has elapsed during the supply of electrical energy to the second heating element 52b, the controller <NUM> may be configured to decrease the supply of electrical energy to the second heating element 52b and to simultaneously increase the supply of electrical energy to the third heating element 52c, until such time as the energy supply to the second heating element 52b ceases and the energy supply to the third heating element 52c reaches a maximum level. As a consequence, a third portion of the aerosol generating material <NUM> is now heated in the region designated C in <FIG> by heat transferred from the third heating element 52c.

The controller <NUM> continues to implement the methodology described above so that electrical energy is sequentially supplied by the power source <NUM> to the fourth and fifth heating elements 52d, 52e, thereby sequentially heating fourth and fifth portions of the aerosol generating material <NUM> in the regions designated D and E in <FIG>.

After detecting a predetermined number of puffs or after detecting that a predetermined period of time has elapsed during the supply of electrical energy to the fifth heating element 52e, the controller <NUM> decreases the supply of electrical energy to the fifth heating element 52e until the electrical energy supplied to the heating element 52e ceases. At this point, no further heating of the aerosol generating material <NUM> takes place and the controller <NUM> may be configured to prevent the supply of electrical energy from the power source <NUM> to the heating elements 52a-e until the used aerosol generating article <NUM> has been removed from the cavity <NUM> and a replacement aerosol generating article <NUM>, containing previously unheated aerosol generating material <NUM>, has been inserted into the cavity <NUM>.

In another mode, two or more of the heating circuits 40a-e may be supplied with electrical energy at the same time to simultaneously heat two or more portions of the aerosol generating material <NUM>. For example, the methodology can consist of simultaneously heating two regions A and B of the aerosol generating material <NUM> while the other regions C, D, E remain unheated. The heating operation can be continued for heating the other regions C, D, E with the heating elements 52c-52e either individually or in pairs or groups.

Referring to <FIG>, there is shown a first type of positioning mechanism <NUM> in combination with the first example of the aerosol generating device <NUM> illustrated in <FIG>, for simultaneously moving the pairs of electrical contacts 42a-e from the first position shown in <FIG> and <FIG> to the second position shown in <FIG> and <FIG>. The positioning mechanism <NUM> comprises a radially movable pusher <NUM>, which may be activated manually by a user. The radially movable pusher <NUM> is movable in the radial direction (as shown by the double headed arrow in <FIG>) between a first (retracted) position shown in <FIG> and a second (advanced) position shown in <FIG>.

Referring to <FIG>, there is shown a second type of positioning mechanism <NUM> in combination with the second example of the aerosol generating device <NUM> illustrated in <FIG>, for sequentially moving the heating elements 52a-e from the first position shown in <FIG> and <FIG> to the second position shown in <FIG> and <FIG>. The positioning mechanism <NUM> comprises an axially movable pusher <NUM>, which may be activated manually by a user. The axially movable pusher <NUM> is movable in the axial direction (as shown by the double headed arrow in <FIG>) between a first (retracted) position shown in <FIG> and a second (advanced) position shown in <FIG>.

Although the first type of positioning mechanism <NUM> has been described in combination with the first example of the aerosol generating device <NUM> illustrated in <FIG>, it could equally be used with the second example of the aerosol generating device <NUM> illustrated in <FIG>. Similarly, although the second type of positioning mechanism <NUM> has been described in combination with the second example of the aerosol generating device <NUM> illustrated in <FIG>, it could equally be used with the first example of the aerosol generating device <NUM> illustrated in <FIG>.

Although exemplary embodiments have been described in the preceding paragraphs, it should be understood that various modifications may be made to those embodiments without departing from the scope of the appended claims. Thus, the breadth and scope of the claims should not be limited to the above-described exemplary embodiments.

Any combination of the above-described features in all possible variations thereof is encompassed by the present disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.

Claim 1:
An aerosol generating device (<NUM>, <NUM>) comprising:
a housing (<NUM>) defining a cavity (<NUM>) for receiving an aerosol generating material (<NUM>);
a power source (<NUM>) and a controller (<NUM>);
a plurality of heating circuits (40a-e) for heating the aerosol generating material (<NUM>), each heating circuit comprising a pair of electrical contacts (42a-e) movable between a first position in which the pair of electrical contacts does not extend into the aerosol generating material (<NUM>) and a second position in which the pair of electrical contacts extends into the aerosol generating material (<NUM>);
wherein the controller (<NUM>) is configured to control the power source (<NUM>) to independently supply electrical energy to one or more pairs of the electrical contacts (42a-e) when the electrical contacts are in the second position.