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 such approach is to provide an aerosol generating device which employs an induction heating system and into which an aerosol generating article, comprising aerosol generating material, can be removably inserted by a user. In such a device, an induction coil is provided with the device and an induction heatable susceptor is provided with the aerosol generating material. Electrical energy is provided to the induction coil when a user activates the device which in turn generates an alternating electromagnetic field. The susceptor couples with the electromagnetic field and generates heat which is transferred, for example by conduction, to the aerosol generating material and an aerosol is generated as the aerosol generating material is heated.

Embodiments of the present disclosure seek to provide an improved aerosol generating system.

According to a first aspect of the present disclosure, there is provided an aerosol generating system according to claim <NUM>.

The system may comprise the aerosol generating material in the aerosol generating space and inside/outside of the tubular member of the susceptor.

According to claim <NUM>, the tubular member has an outer cylindrical surface and an inner cylindrical surface. The outer and inner cylindrical surfaces are continuous surfaces.

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 an aerosol for inhalation by a user of the aerosol generating system.

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 susceptor is reusable and is a separate component to the aerosol generating material. A susceptor does not, therefore, need to be provided with the aerosol generating material making it easier and cheaper to manufacture than, for example, an aerosol generating article which incorporates aerosol generating material and one or more induction heatable susceptors integrated into the aerosol generating article. The risk of contamination, e.g., metal contamination, of the aerosol generating material by the induction heatable susceptor during storage is also eliminated or at least reduced because the induction heatable susceptor is brought into contact with the aerosol generating material only at the point of use, when aerosol generating material is positioned in the aerosol generating space of the aerosol generating device.

Positioning the susceptor in the aerosol generating space allows the positional relationship between the susceptor and the induction coil to be fixed, thereby ensuring optimal coupling between the electromagnetic field produced by the induction coil and the susceptor.

The provision of a susceptor in the form of a tubular member and of aerosol generating material located inside and outside of the tubular member provides for optimum heat transfer from the susceptor to the aerosol generating material. This in turn provides for optimum heating of the aerosol generating material and ensures that the characteristics of the aerosol generated during use of the aerosol generating system are optimised.

The aerosol generating device may include air inlet ports which direct air flowing into the aerosol generating space both to the interior of the tubular member and to the exterior of the tubular member. The air inlet ports ensure that air is directed to the aerosol generating material positioned both inside and outside the tubular susceptor, thereby maximising the generation and delivery of aerosol from the aerosol generating space through an air outlet of the aerosol generating device.

The susceptor may be removably mounted in the aerosol generating space. With this arrangement, the susceptor is provided as a separate component to the other components of the aerosol generating device. The susceptor can, therefore, be easily replaced at appropriate time intervals, for example if it is damaged, soiled or contaminated, for example with deposits of aerosol generating material following a period of use.

The aerosol generating device may include a connector for removably mounting the susceptor, for example in the aerosol generating space. The provision of a connector allows for easy removable mounting of the susceptor and may advantageously ensure an appropriate positional relationship between the susceptor and the induction coil.

The controller may be configured to detect the mounting of the susceptor in the aerosol generating space. The controller may be configured to indicate a timing change of the susceptor. For example, the controller may be configured to detect a predetermined power level supplied to the induction coil and to indicate a timing change of the susceptor based on the detected power level.

The controller may be configured to detect the positioning of a new susceptor in the aerosol generating space. The controller may be configured to indicate a timing change of the susceptor after detecting the positioning of a new susceptor in the aerosol generating space, for example based on the detected power level. Alternatively or in addition, the controller may be configured to cease power supply to the induction coil after detecting the positioning of a new susceptor in the aerosol generating space and based on the detected power level. This arrangement ensures that the reusable susceptor is replaced at appropriate time intervals to ensure optimum heating of the aerosol generating material.

In an embodiment, the controller may be configured to detect the positioning of a new susceptor in the aerosol generating space by detecting a characteristic associated with the susceptor. The characteristic could be an identification characteristic and could comprise an identification signal, for example emitted by a RFID tag associated with the susceptor. Alternatively, the user could indicate that the susceptor has been replaced with a new susceptor, e.g. by performing a predetermined action such as a button press or a series of button presses, etc..

The controller may be configured to detect the consumption of aerosol generating material by detecting at least one of the following:.

The aerosol generating device may include a sensor, for example an optical sensor, to enable the controller to detect the placement of aerosol generating material in the aerosol generating space.

The aerosol generating device may include one or more sensors to detect the movement of the one or more component parts, such as a mouthpiece or cover to allow access to the aerosol generating space, to enable the controller to detect the movement of the one or more components of the aerosol generating device.

The controller may be configured to detect the level of consumption of aerosol generating material and to indicate a timing change of the susceptor (that is to indicate that it is time to change the susceptor or to indicate the remaining "life" of the susceptor before it should optimally be changed, etc.) based on the detected consumption level and/or to cease power supply to the induction coil based on the detected consumption level. The controller may be configured to detect the level of consumption of aerosol generating material after detecting the positioning of a new susceptor in the aerosol generating space. The controller may be further configured to indicate a timing change of the susceptor based on the detected consumption level after detecting the positioning of a new susceptor in the aerosol generating space and/or to cease power supply to the induction coil based on the detected consumption level after detecting the positioning of a new susceptor in the aerosol generating space and until the positioning of a new susceptor in the aerosol generating space is detected. Again, this arrangement ensures that the reusable susceptor is replaced at appropriate time intervals to ensure optimum heating of the aerosol generating material.

The susceptor may be positioned in the aerosol generating space so that a longitudinal axis of the susceptor is substantially aligned with a longitudinal axis of the induction coil. This positional relationship ensures optimum coupling of the electromagnetic field generated by induction coil with the susceptor.

The aerosol generating space may comprise a cavity.

The aerosol generating material may comprise a non-liquid aerosol generating material.

The aerosol generating material may comprise one or more selected from the group consisting of granules, particles, gel, strips, loose leaves, cut filler, pellets, powder, shreds, strands, foam material and sheets. Thus, common and widely available aerosol generating materials can be used for aerosol generation. The aerosol generating material may comprise plant derived material and in particular, may comprise tobacco.

The aerosol generating material may be provided in a housing connected to a mouthpiece, for example in the form of an aerosol generating article which can be inserted into the aerosol generating space. The housing may, for example, comprise a non-electrically conductive material and may, for example, comprise a paper wrapper. The provision of an aerosol generating article may facilitate use of the aerosol generating system.

The aerosol generating article may be elongate and may be substantially cylindrical. The cylindrical shape of the aerosol generating article with its circular cross-section may advantageously facilitate insertion of the aerosol generating article into the aerosol generating space, in particular when the induction coil is a helical induction coil having a circular cross-section. The ability of the aerosol generating space to receive a substantially cylindrical aerosol generating article to be heated is advantageous as, often, vaporisable aerosol generating substances, and tobacco products in particular, are packaged and sold in a cylindrical form.

The induction coil may be arranged to operate in use with a fluctuating electromagnetic field having a magnetic flux density of between approximately 20mT and approximately <NUM>. 0T at the point of highest concentration.

The aerosol generating device may include a power source. The power source and the controller may be configured to operate at a high frequency. The power source and controller may be configured to operate at a frequency of between approximately <NUM> and <NUM>, possibly between approximately <NUM> and <NUM>, and possibly at approximately <NUM>. The power source and circuitry could be configured to operate at a higher frequency, for example in the MHz range, depending on the type of inductively heatable susceptor that is used.

Whilst the induction coil may comprise any suitable material, typically the induction coil may comprise a Litz wire or a Litz cable.

Whilst the aerosol generating device may take any shape and form, it may be arranged to take substantially the form of the induction coil, to reduce excess material use. As noted above, the induction coil may be substantially helical in shape and may have a circular cross-section, thus the aerosol generating device may be substantially cylindrical and may have a substantially circular cross-section.

The circular cross-section of a helical induction coil facilitates the insertion of aerosol generating material and/or an aerosol generating article into the aerosol generating space and ensures uniform heating of the aerosol generating material and/or the aerosol generating article. The resulting shape of the aerosol generating device is also comfortable for the user to hold.

The susceptor may comprise one or more, but not limited, of aluminium, iron, nickel, stainless steel and alloys thereof, e.g. Nickel Chromium or Nickel Copper. With the application of an electromagnetic field in its vicinity, the susceptor may generate heat due to eddy currents and magnetic hysteresis losses resulting in a conversion of energy from electromagnetic to heat.

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 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 embodiment of an aerosol generating system <NUM>. The aerosol generating system <NUM> comprises an aerosol generating device <NUM> having a proximal end <NUM> and a distal end <NUM>. The aerosol generating device <NUM> comprises a device body <NUM> which includes a power source <NUM> and a controller <NUM> which may be configured to operate at high frequency. 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 comprises a generally cylindrical aerosol generating space <NUM> formed as a cavity in the device body <NUM> at the proximal end <NUM> of the aerosol generating device <NUM>. The aerosol generating space <NUM> is arranged to receive aerosol generating material <NUM>, as shown in <FIG> and <FIG>, for example in the form of granules, particles, gel, strips, loose leaves, cut filler, pellets, powder, shreds, strands, foam material and sheets.

The aerosol generating device <NUM> comprises a helical induction coil <NUM> which has a circular cross-section and which extends around the aerosol generating space <NUM>. The induction coil <NUM> can be energised by the power source <NUM> and controller <NUM>. The controller <NUM> includes, amongst other electronic components, an inverter which is arranged to convert a direct current from the power source <NUM> into an alternating highfrequency current for the induction coil <NUM>.

The aerosol generating device <NUM> comprises a mouthpiece <NUM> which is removably mountable on the device body <NUM> at the proximal end <NUM> and through which a user may inhale vapour generated during use of the device <NUM>. The mouthpiece <NUM>, which is shown diagrammatically in <FIG>, includes an air outlet <NUM> which allows aerosol generated during use of the device <NUM> to flow from the aerosol generating space <NUM> and into the mouth of a user.

The aerosol generating system <NUM> comprises a tubular susceptor <NUM> which is formed of material that is inductively heatable in the presence of a time varying electromagnetic field generated by the induction coil <NUM>. The susceptor <NUM> is positioned in use concentrically in the aerosol generating space <NUM>. The susceptor <NUM> can be permanently mounted in the aerosol generating space <NUM>, for example as an integral component of the aerosol generating device <NUM>, or can be removably mounted in the aerosol generating space <NUM>, for example by a suitable connector (not shown). As will be apparent from <FIG>, the susceptor <NUM> is positioned in the aerosol generating space <NUM> so that its longitudinal axis is substantially aligned with a longitudinal axis of the induction coil <NUM>. Aerosol generating material <NUM> is located in use both inside and outside of the tubular susceptor, as can be clearly seen in <FIG>.

In the case where the susceptor <NUM> is a separate element which is removably connectable to the aerosol generating device <NUM> in the aerosol generating space <NUM>, it may be securely removably attached by a suitable connection mechanism. For example, the device <NUM> may include a cooperating recess into which an end of the susceptor <NUM> may be snugly fitted with a friction fit or with a screw fit (if supplied with a screw ridge or groove cooperating with a matching groove or ridge formed in the recess) or with a bayonetted fitting. Additionally or alternatively, the device <NUM> may include a magnet for securely attaching the susceptor <NUM> in a well-defined position within the aerosol generating space <NUM>.

When a time varying electromagnetic field is produced in the vicinity of the susceptor <NUM> by the induction coil <NUM>, heat is generated in the susceptor <NUM> due to eddy currents and/or magnetic hysteresis losses and the heat is transferred from the susceptor <NUM> to the aerosol generating material <NUM> located both inside and outside of the tubular susceptor <NUM> to heat the aerosol generating material <NUM> without burning it and to thereby generate an aerosol for inhalation by a user. The tubular susceptor <NUM> is in contact over substantially its entire inner and outer surfaces with the aerosol generating material <NUM>, thus enabling heat to be transferred directly, and therefore efficiently, from the susceptor <NUM> to the aerosol generating material <NUM>.

The aerosol generating device <NUM> includes an air inlet <NUM> which delivers air to the aerosol generating space via inlet ports <NUM>, <NUM> which are positioned so that they direct the air both to the interior of the tubular susceptor <NUM> and to the exterior of the tubular susceptor <NUM>. It will be understood that this arrangement maximises the generation and delivery of aerosol from the aerosol generating space <NUM> through the air outlet <NUM>.

As noted above, the mouthpiece <NUM> is conveniently removable from the device body <NUM> to allow access to the aerosol generating space <NUM>. Thus, the mouthpiece <NUM> can be removed to allow aerosol generating material <NUM> to be inserted into the aerosol generating space <NUM> and subsequently reattached to the device body <NUM> so that the aerosol generating system <NUM> can be used for aerosol generation. After a period of use, the mouthpiece <NUM> can be removed again to allow the used aerosol generating material <NUM> to be removed and to enable the placement of further aerosol generating material <NUM> in the aerosol generating space <NUM>. In addition, it will be understood that removal of the mouthpiece <NUM> also allows access to the susceptor <NUM> so that, in the case of a removably mounted susceptor <NUM>, it can be removed and replaced if appropriate.

In some embodiments which utilise a removably mounted susceptor <NUM>, the controller <NUM> can be configured to detect the mounting of a new susceptor <NUM> in the aerosol generating space <NUM>, for example by detecting an identification characteristic associated with the susceptor <NUM> or as a result of the user indicating that the susceptor <NUM> has been replaced with a new susceptor <NUM> (e.g. by performing a predetermined button press or series of presses, etc.). After detecting the mounting of a new susceptor <NUM>, the controller <NUM> can be further configured to detect the power level supplied to the induction coil <NUM> and to indicate a timing change of the susceptor <NUM> (that is to indicate that it is time to change the susceptor <NUM> or to indicate the remaining "life" of the susceptor <NUM> before it should optimally be changed, etc.) based on the detected power level and/or to cease power supply to the induction coil <NUM> based on the detected power level until the controller <NUM> detects that another new susceptor <NUM> has been positioned in the aerosol generating space <NUM>. In particular, the device <NUM> can monitor the total energy supplied to the induction coil <NUM> over time since inserting a new susceptor <NUM> (by integrating the power supplied to the coil <NUM> over time) and can determine that after a predetermined amount of energy has been supplied to the coil <NUM> it is time for the susceptor <NUM> to be changed. A notification that the susceptor <NUM> should be changed can be provided to the user via any suitable means - e.g. by a warning light flashing in a predetermined pattern, etc..

In some embodiments, the controller <NUM> can be configured to detect the consumption of aerosol generating material <NUM> by detecting one or more of: the number of puffs; the length of the total puff period; the number of placements of aerosol generating material <NUM> in the aerosol generating space <NUM>, for example using an optical sensor (not shown); and the movement of one or more components of the aerosol generating device <NUM>, for example the movement of the mouthpiece <NUM>, that are required to allow the placement of aerosol generating material <NUM> in the aerosol generating space <NUM>. Additionally it should be noted that the techniques for determining that a susceptor <NUM> should be changed could generally also be used for detecting the amount of consumption of aerosol material <NUM> and vice versa as will be apparent to a person skilled in the art.

In some embodiments, the controller <NUM> can advantageously be configured to detect the level of consumption of aerosol generating material <NUM> after detecting the positioning of a new susceptor <NUM> in the aerosol generating space <NUM>, and can be configured to indicate a timing change of the susceptor <NUM> based on the detected consumption level and/or to cease power supply to the induction coil <NUM> based on the detected consumption level until the controller <NUM> detects that another new susceptor <NUM> has been positioned in the aerosol generating space <NUM>.

Referring now to <FIG>, there is shown a second embodiment of an aerosol generating system <NUM> which is similar to the aerosol generating system <NUM> illustrated in <FIG> and in which corresponding elements are designated using the same reference numerals.

The aerosol generating system <NUM> comprises an aerosol generating device <NUM> which is identical to the aerosol generating device <NUM> described above in all respects except that it does not include the removable mouthpiece <NUM>.

In the aerosol generating system <NUM>, the aerosol generating material <NUM> is provided in a non-electrically conductive housing <NUM>, for example in the form of a paper wrapper, that is connected to a mouthpiece <NUM>. The aerosol generating material <NUM>, the housing <NUM> and the mouthpiece <NUM> together constitute an aerosol generating article <NUM> which can be removably positioned in the aerosol generating space <NUM>. It will be understood that the tubular susceptor <NUM> penetrates the aerosol generating material <NUM> and may extend fully into the aerosol generating material <NUM> when the aerosol generating article <NUM> is positioned in the aerosol generating space <NUM>, and that the mouthpiece <NUM> projects from the distal end <NUM> of the aerosol generating device <NUM> so that it can be engaged by a user's lips.

The aerosol generating system <NUM> operates in the same manner as the aerosol generating system <NUM> described above, so that when a time varying electromagnetic field is produced in the vicinity of the susceptor <NUM> by the induction coil <NUM>, heat is generated in the susceptor <NUM> and is transferred from the susceptor <NUM> to the aerosol generating material <NUM> located both inside and outside of the tubular susceptor <NUM> to heat the aerosol generating material <NUM> without burning it and to thereby generate an aerosol for inhalation by a user. The aerosol generated due to heating of the aerosol generating material <NUM> is inhaled by a user through the mouthpiece <NUM>.

After a period of use, the aerosol generating article <NUM> can be removed from the aerosol generating space <NUM> and a further aerosol generating article <NUM> can be positioned in the aerosol generating space <NUM>. In addition, it will be understood that removal of the aerosol generating article <NUM> allows access to the susceptor <NUM> so that, in the case of a removably mounted susceptor <NUM>, it can be removed and replaced if appropriate.

Referring now to <FIG>, there is shown a third embodiment of an aerosol generating system <NUM> which is similar to the aerosol generating system <NUM> illustrated in <FIG> and in which corresponding elements are designated using the same reference numerals.

The aerosol generating system <NUM> comprises an aerosol generating device <NUM> which is identical to the aerosol generating device <NUM> described above in all respects except that the susceptor <NUM> is mounted on the mouthpiece <NUM> and extends from the mouthpiece <NUM> into the aerosol generating space <NUM> when the mouthpiece <NUM> is positioned on the device body <NUM> at the proximal end <NUM> of the aerosol generating device <NUM> as shown in <FIG>. Thus, the susceptor <NUM> is removably mounted in the aerosol generating space <NUM> by virtue of the removable mounting of the mouthpiece <NUM> on the device body <NUM> at the proximal end <NUM> of the aerosol generating device <NUM>.

With this arrangement, the susceptor <NUM> can be formed with the mouthpiece <NUM> as an integral component such that replacement of the susceptor <NUM> will necessitate replacement of the mouthpiece <NUM>. Alternatively, the susceptor <NUM> can be removably mounted on the mouthpiece <NUM>, for example by a connector (not shown), so that the susceptor <NUM> can be removed and replaced after a period of use without replacement of the mouthpiece <NUM>.

Referring now to <FIG>, there is shown a fourth embodiment of an aerosol generating system <NUM> which is similar to the aerosol generating system <NUM> illustrated in <FIG> and in which corresponding elements are designated using the same reference numerals.

The aerosol generating system <NUM> comprises an aerosol generating device <NUM> having an integrally formed mouthpiece <NUM> at the proximal end <NUM> of the aerosol generating device <NUM> and in which the aerosol generating space <NUM> is located at the distal end <NUM> of the device <NUM>. A cover <NUM> for the aerosol generating space <NUM> is removably mountable on the device body <NUM> at the distal end <NUM>. The cover includes air inlet ports <NUM>, <NUM> which are positioned so that they direct air both to the interior of the tubular susceptor <NUM> and to the exterior of the tubular susceptor <NUM>. It will be understood that this arrangement maximises the generation and delivery of aerosol from the aerosol generating space <NUM> along air passage <NUM> and through the air outlet <NUM>.

In the aerosol generating system <NUM>, the susceptor <NUM> is mounted on the cover <NUM> and extends from the cover <NUM> into the aerosol generating space <NUM> when the cover <NUM> is positioned on the device body <NUM> at the distal end <NUM> of the aerosol generating device <NUM> as shown in <FIG>. Thus, the susceptor <NUM> is removably mounted in the aerosol generating space <NUM> by virtue of the removable mounting of the cover <NUM> on the device body <NUM> at the distal end <NUM> of the aerosol generating device <NUM>.

With this arrangement, the susceptor <NUM> can be formed with the cover <NUM> as an integral component such that replacement of the susceptor <NUM> will necessitate replacement of the cover <NUM>. Alternatively, the susceptor <NUM> can be removably mounted on the cover <NUM>, for example by a connector (not shown), so that the susceptor <NUM> can be removed and replaced after a period of use without replacement of the cover <NUM>.

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.

Claim 1:
An aerosol generating system (<NUM>, <NUM>, <NUM>, <NUM>) comprising:
an aerosol generating device (<NUM>, <NUM>, <NUM>, <NUM>) comprising:
an aerosol generating space (<NUM>) for receiving aerosol generating material (<NUM>);
an induction coil (<NUM>) extending around the aerosol generating space (<NUM>); and
a controller (<NUM>);
a susceptor (<NUM>) which is inductively heatable in the presence of a time varying electromagnetic field;
wherein the susceptor (<NUM>) is separable from aerosol generating material (<NUM>) located, in use, in the aerosol generating space (<NUM>) and comprises a tubular member positioned, in use, in the aerosol generating space (<NUM>), and wherein the aerosol generating material (<NUM>) is located, in use, inside and outside of the tubular member,
characterised in that,
the tubular member has an outer cylindrical surface and an inner cylindrical surface, wherein the outer and inner cylindrical surfaces are continuous.