Patent Description:
The popularity and use of aerosol-generating devices and systems (also known as vaporisers) has grown rapidly in the past few years as an alternative to traditional tobacco products such as cigarettes, cigars, cigarillos, and rolling tobacco. Various devices and systems are available that heat or warm aerosolisable substances, that may or may not comprise nicotine or other active substances, as opposed to burning tobacco in conventional tobacco products.

A commonly available aerosol-generating system is the heated substrate aerosol generation or heat-not-burn type. Systems of this type generate an aerosol or vapour by heating a consumable article (i.e. a "heat-not-burn stick") containing an aerosol forming substrate such as reconstituted tobacco to a temperature typically in the range of <NUM> to <NUM>. Heating an aerosol forming substrate, but not combusting or burning it, releases an aerosol that comprises the components sought by the user but not the undesirable by-products of combustion. 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 which can be unpleasant for the user.

Typically, a heat-not-burn consumable article, for example in stick form, is inserted into a cavity of a heat-not-burn device, with an end of the stick left protruding from the device and forming an inhalation mouthpiece. A heater in the heat-not-burn device subsequently supplies heat to the stick to aerosolise aerosolisable material contained in the aerosol forming substrate in the stick, and the aerosol produced is supplied to the user from the protruding end of the stick.

Typically, not all the heat produced by the heater is transferred to the consumable article to generate the aerosol. This decreases the overall efficiency of the device and reduces the battery life. Furthermore, the losses may lead to heating of other components in the device, which may lead to damage and may cause discomfort to the user when holding the device.

It is an object of the present invention to address these problems.

In the prior art, <CIT> relates to an aerosol generating device comprising a chamber, an infrared emitter having a tubular base, and a conductive element supported by a retaining mechanism; <CIT> relates to an aerosol generating device including a heater configured to heat an aerosol generating article, and a heater flange supporting one end of the heater; <CIT> relates to a heater comprising a basal body, and coupling electrodes arranged at the same end of the basal body; <CIT> relates to a heating assembly comprising a heating pipe, and a heating cavity having a cross section which is polygonal; and <CIT> relates to a heating body and a heating device.

According to an aspect of the invention, there is provided an aerosol generating device, comprising: an insulator comprising an interior wall and an exterior wall that are separated from one another, a cavity defined within the interior wall in which an aerosol forming substrate can be received, and a heater positioned to heat the aerosol forming substrate when it is received in the cavity; a casing that surrounds the insulator; and electrical contacts that are connected to the heater, wherein at least one of the electrical contacts is mechanically connectable to the casing in order to hold the insulator in place.

Advantageously, since the electrical contacts also provide the mechanical connection between the insulator and the casing, the number of heat conduction paths therebetween is reduced. By reducing the amount of heat that is conducted from the insulator to the casing, the efficiency of the heater may be increased, since a greater proportion of the heat may be transferred to the aerosol forming substrate. Furthermore, heating of the casing is reduced, which may reduce damage to other components of the device located in the casing and may be desirable from the perspective of the user holding the casing.

The insulator and the heater may together be referred to as a heating apparatus. The heating apparatus may be received within a chamber of the casing, such as a chamber defined by a side portion of the casing that extends from a base portion of the casing. The heating apparatus may be received within the chamber such that an air gap is provided between the exterior wall of the insulator and the casing. The region between the interior and exterior wall of the insulator may be referred to as the insulating region.

Preferably, the electrical contacts provide the only connection between the insulator and the casing. Advantageously, this reduces heat transferred between the insulator and the casing by minimizing the number of heat conduction paths therebetween. In other words, preferably the only way in which heat may be conducted between the insulator and the casing is through the electrical contacts.

Preferably, the interior wall and the exterior wall of the insulator are separated from one another by a vacuum, thereby providing a vacuum insulator. In this way, conduction and/or convection of heat between the interior and exterior wall of the insulator is further inhibited, which further reduces transfer of heat from the insulator to the casing. Alternatively, the interior wall and the exterior wall of the insulator may be separated from one another by an air gap, aerogel, foamed material, fibrous material, and/or any combination of the above.

Preferably, the insulator is removable from within the casing. In other words, at least one of the electrical contacts is mechanically disconnectable from the casing.

For example, the heating apparatus that provides the insulator and the heater may be removable from the casing, such as from within the chamber. In this way, the insulator may be replaced, cleaned and/or repaired. Alternatively, the insulator may be permanently fixed within the casing, which may enable a stronger connection therebetween.

The cavity may comprise at least one opening at which the interior wall is joined to the exterior wall, and the one or more electrical contacts may be positioned on the insulator at a location that minimises heat flow between the at least one opening and the electrical contacts. In this way, the electrical contacts are made to the part of the exterior wall that remains coolest during use of the aerosol generating device. This reduces the transfer of heat between the insulator and the casing. For example, the electrical contacts may be positioned at a location that maximises the shortest distance between the at least one opening and the electrical contacts. In other words, where there are multiple openings to the cavity, the electrical contacts are not placed in proximity to any of them. The distance may be determined along the direct path between the opening and the electrical contacts. Preferably, the distance is determined along a thermal pathway between the opening and the electrical contacts; since heat flow is inhibited through the insulating portion of the insulator, the distance may be measured along a thermal pathway through the air surrounding the insulator, and/or along the external wall of the insulator.

The insulator may be cup-shaped such that the cavity has a single opening at which the interior wall is joined to the exterior wall, and wherein the electrical contacts are positioned at a base of the insulator that is opposite to the opening of the cavity. In other words, the insulator may be attached to the casing in a cantilever arrangement, where only one end of the insulator is connected to the casing. By providing the electrical contacts at the base of the insulator, the electrical contacts are made to the coolest part of the exterior wall during use, thereby reducing the transfer of heat from the insulator to the casing. In other words, the distance between the electrical contacts and the opening of the cavity is maximised.

Alternatively, the insulator may be tube-shaped such that the cavity has two openings at which the interior wall is joined to the exterior wall, and wherein the electrical contacts are positioned on a side of insulator that is spaced from both of the two openings. The electrical contacts may be arranged equidistant from both of the openings to the cavity, thereby maximising the shortest distance to both of the openings. Alternatively, if one of the openings is determined to produce more heat than the other, the electrical contacts may be moved further from that opening. In this way, the electrical contacts are made to the coolest part of the exterior wall during use, thereby reducing the transfer of heat from the insulator to the casing.

The electrical contacts may be mechanically connectable to a base portion of the casing. By connecting the electrical contacts to the base portion of the casing, transfer of the heat to a side portion (that may be held by the user) of the aerosol generating device is reduced. Alternatively, the electrical contacts may be mechanically connectable to a side portion of the casing. The side portion of the casing may comprise an inner wall and an outer wall, and the electrical contacts may be mechanically connectable to the inner wall. An insulating material may be located between the inner and the outer wall, thereby further reducing transfer of heat from the insulator to the casing.

The electrical contacts may comprise a pair of pins. The pair of pins may be connectable to the casing with a lockable coupling. The pair of pins may be connectable to the casing using a bayonet connection or a screw thread.

The electrical contacts may comprise a pin and a threaded outer surface that is engageable with the casing to hold the insulator in place.

It will be understood by a skilled person that any device or apparatus feature described herein may be provided as a method feature. It will be understood that particular combinations of the various features described and defined in any aspects described herein can be implemented and/or supplied and/or used independently. Moreover, it will be understood that the present invention is described herein purely by way of example, and modifications of detail can be made within the scope of the invention.

One or more embodiments will now be described, purely by way of example, with reference to the accompanying figures, in which:.

In the following description and accompanying drawings, corresponding features may preferably be identified using corresponding reference numerals to avoid the need to describe said common features in detail for each and every embodiment.

<FIG> depicts a schematic cross section of a first embodiment of an aerosol generating device <NUM>. The device <NUM> has a casing <NUM> with a base portion <NUM> and a side portion <NUM>. More specifically, the side portion <NUM> extends from the base portion <NUM> to define a chamber <NUM>. In this embodiment the side portion <NUM> comprises an outer wall 14a and an inner wall 14b, though it will be appreciated that the side portion <NUM> may also comprise only a single wall.

The device <NUM> comprises a heating apparatus <NUM> held within the casing <NUM>, such as within the chamber <NUM>. In this way, the casing <NUM> surrounds the heating apparatus <NUM>. Further detail of the heating apparatus <NUM> is shown in the cross section in <FIG>. The heating apparatus <NUM> comprises an insulator <NUM>. The insulator <NUM> comprises an internal wall <NUM> and an external wall <NUM>, which are spaced apart from one another so that an insulating region <NUM> is enclosed in the space between them. Preferably the insulating region <NUM> comprises a vacuum, thereby providing a vacuum insulator <NUM>. Alternatively or additionally, the insulating region <NUM> may comprise an air gap, aerogel, foamed material, fibrous material and/or any combination of the above.

The heating apparatus <NUM> comprises a cavity <NUM> that is provided adjacent the internal wall <NUM> and is configured to receive an aerosol forming substrate. For example, a consumable <NUM> may be inserted into the cavity <NUM> where the consumable <NUM> contains an aerosol forming substrate such as tobacco <NUM>. The consumable <NUM> is typically an elongate rod or stick that can be inserted into the cavity <NUM> by a user via an opening <NUM> to the cavity <NUM>. The insulator <NUM> has a substantially cylindrical shape that enables the insulator <NUM> to fully surround the consumable <NUM> to maximise the effectiveness of the insulation. In this example, the insulator <NUM> comprises an opening <NUM> for receiving the consumable <NUM> at one longitudinal end and is closed at the opposite end. Thus, when viewed perpendicularly to its longitudinal axis, the insulator <NUM> has a cross section that is cup-shaped. In other words, the cavity <NUM> has a single opening <NUM> at which the interior wall <NUM> is joined to the exterior wall <NUM>.

A heater <NUM> is provided within the insulating region <NUM> and on the internal wall <NUM>. The heater <NUM> is configured to heat the internal wall <NUM> by conduction so that the internal wall <NUM> heats the consumable <NUM> and the air inside the cavity <NUM> by conduction and radiation. The heater <NUM> is powered by a power source such as a battery (not shown) located in the base portion <NUM> of the casing <NUM> of the device <NUM>.

By providing an insulator <NUM> in the heating apparatus <NUM>, the amount of heat that is wasted is reduced, since the insulating region <NUM> inhibits conduction or convection of heat from the heater <NUM> directly to the external wall <NUM>. Nonetheless, during use of the device <NUM> the external wall <NUM> may heat up, such as due to convection of air from the opening <NUM> of the cavity <NUM>, or due to conduction between the internal wall <NUM> and the external wall <NUM> at the opening <NUM>. By providing the heating apparatus <NUM> within a chamber <NUM> of the device <NUM>, an air gap is provided between the external wall <NUM> of the heating apparatus <NUM> and the casing <NUM> of the device <NUM>. Advantageously, this may reduce heating of the casing <NUM>, thereby increasing efficiency of the device <NUM> and preventing discomfort to a user holding the casing <NUM> of the device <NUM>.

The heating apparatus <NUM> comprises one or more electrical contacts <NUM> connected to the heater <NUM>, such as by a first wire connector 114a and a second wire connector 114b. The electrical contacts <NUM> are mechanically connectable to the casing <NUM> of the device <NUM>. In this embodiment, the electrical contacts <NUM> are mechanically connectable to the base portion <NUM> of the casing <NUM>. By providing both the mechanical and electrical connection between the insulator <NUM> and the casing <NUM> using the same means, the number of heat conduction pathways is reduced. Advantageously, this may further reduce heating of the casing <NUM>, thereby increasing efficiency of the device <NUM> and preventing discomfort to a user holding the casing <NUM> of the device <NUM>.

Preferably, the electrical contacts <NUM> provide the only connection between the insulator <NUM> and the casing <NUM>. In this way, the number of heat conduction pathways is minimized, which further reduces the transfer of heat between the insulator <NUM> and the casing <NUM>. To achieve this, the materials and shape of the electrical contacts <NUM> are chosen to provide sufficient strength to keep the heating apparatus <NUM> in place within the chamber <NUM> during use of the device <NUM>, without the need for additional contact points between the heating apparatus <NUM> and the casing <NUM>. In other words, the electrical contacts <NUM> provide a rigid connection whereby movement of the insulator <NUM> relative to the casing <NUM> is inhibited.

Preferably, the electrical contacts <NUM> are also mechanically disconnectable from the casing <NUM>, such that the heating apparatus <NUM> is removable from the casing <NUM>. Advantageously, by providing a heating apparatus <NUM> that is removable from the casing <NUM>, parts of the heating apparatus <NUM> may be easily repaired and/or replaced without the need to replace the entire device <NUM>.

In this example, the electrical contacts <NUM> comprise a pair of pins. The pins may be connectable to the casing <NUM> with a lockable coupling. The pins may be inserted into the base portion <NUM> and locked in place via a small rotation or translation.

In one implementation, the connection between the pins and the base portion <NUM> may correspond to the connection used between a fluorescent starter and its corresponding socket. More specifically, the pins may comprise a flanged portion that retains the pins within an overhung groove in the base portion <NUM>, where movement of the pins though the groove (e.g. by rotation of the heating apparatus <NUM>) allows them to be removed from the base portion <NUM> at an opening. The electrical and mechanical connection between the heating apparatus <NUM> and the casing <NUM> may be provided in other ways. For example, the heating apparatus <NUM> may be connected to the casing <NUM> with a bayonet connector, where radial pins connected to the heating apparatus <NUM> engage within a pair of L-shaped slots on the casing <NUM>. Alternatively, a screw connector may be provided, where the heating apparatus <NUM> comprises a threaded outer surface that is engageable with a corresponding thread in the base portion <NUM> of the casing <NUM>. As a further alternative, the electrical contacts <NUM> may comprise a (single) pin as well as a threaded outer surface that is engageable with the casing <NUM> to hold the insulator <NUM> in place. Such arrangements enable a strong mechanical connection between the heating apparatus <NUM> and the casing <NUM> while also providing a consistent supply of electrical power to the heating apparatus <NUM> via the electrical contacts <NUM>.

The electrical contacts <NUM> are preferably located at a position on the insulator <NUM> that minimises heat flow between the opening <NUM> and the electrical contacts <NUM>. In this way, the electrical contacts <NUM> are made to the part of the exterior wall <NUM> that remains coolest during use of the aerosol generating device <NUM>. This reduces the transfer of heat between the insulator <NUM> and the casing <NUM>. The electrical contacts <NUM> may be located at a position on the insulator <NUM> that maximises their distance from the opening <NUM> of the cavity <NUM>. The maximum distance may correspond to the direct path between the opening <NUM> and the electrical contacts <NUM>. Preferably, the maximum distance is determined to be the maximum distance along a thermal pathway between the opening <NUM> and the electrical contacts <NUM>; since heat flow is inhibited through the insulating region <NUM> of the insulator <NUM>, the distance may be measured along a thermal pathway through the air surrounding the insulator <NUM>, and/or along the external wall <NUM> of the insulator <NUM>.

In the cup-shaped insulator <NUM> shown in <FIG>, the electrical contacts <NUM> may be located at a base of the insulator <NUM> that is opposite to the opening <NUM> of the cavity <NUM>. In other words, the insulator <NUM> is attached to the casing <NUM> in a cantilever arrangement, where only one end of the insulator <NUM> is connected to the casing <NUM>. In this way, the distance along the thermal pathway between the opening <NUM> and the electrical contacts <NUM> is maximized, thereby reducing transfer of heat therebetween. In other words, the electrical contacts <NUM> are made to the coolest part of the exterior wall <NUM> during use, which reduces the amount of heat transferred from the insulator <NUM> to the casing <NUM> of the device <NUM>.

<FIG> depicts a schematic cross section of a second embodiment of an aerosol generating device <NUM>. The device <NUM> is similar to the device <NUM> described above in that it comprises a casing <NUM> with a base portion <NUM> and a side portion <NUM> enclosing a chamber <NUM>. However, the device <NUM> comprises an alternative heating apparatus <NUM>, which is shown in more detail in <FIG>. In <FIG>, the heating apparatus <NUM> is depicted with a consumable <NUM> inserted, where the consumable <NUM> comprises tobacco <NUM> and a filter <NUM>.

Unlike the embodiment shown in <FIG>, the insulator <NUM> in this embodiment is open at both longitudinal ends such that it has a tube-shaped cross-section when viewed perpendicularly to its longitudinal axis. More specifically, the cavity <NUM> has a first opening 211a at a first longitudinal end, and a second opening 211b at a second longitudinal end. The first opening 211a is configured to receive the consumable <NUM>. A plug <NUM> may be provided within the second opening 211b to prevent the consumable <NUM> from being inserted too far into the cavity <NUM>. The plug <NUM> may comprise PEEK, rubber, or other suitable heat resistant materials.

The insulator <NUM> also comprises one or more electrical contacts <NUM> connected to the heater <NUM>. The electrical contacts <NUM> are mechanically connectable to the casing <NUM> of the device <NUM>. In this embodiment, the electrical contacts <NUM> are mechanically connectable to the side portion <NUM> of the casing <NUM>. More specifically, the electrical contacts <NUM> are mechanically connectable to the inner wall 14b of the side portion <NUM> of the casing <NUM>. It will be appreciated that where the side portion <NUM> only has a single wall, the electrical contacts <NUM> may be mechanically connectable to the single (e.g. outer) wall. By providing both the mechanical and electrical connection between the insulator <NUM> and the casing <NUM> using the same means, the number of heat conduction pathways is reduced. Preferably, the electrical contacts <NUM> provide the only connection between the insulator <NUM> and the casing <NUM>. In this way, the number of heat conduction pathways is minimised, which further reduces the transfer of heat between the insulator <NUM> and the casing <NUM>. To achieve this, the materials and shape of the electrical contacts <NUM> are chosen to provide sufficient strength to keep the heating apparatus <NUM> in place within the chamber <NUM> during use of the device <NUM>, without the need for additional contact points between the heating apparatus <NUM> and the casing <NUM>. In other words, the electrical contacts <NUM> provide a rigid connection whereby movement of the insulator <NUM> relative to the casing <NUM> is inhibited.

Preferably, the electrical contacts <NUM> are also mechanically disconnectable from the casing <NUM>, such that the heating apparatus <NUM> is removable from the casing <NUM>. Advantageously, by providing a heating apparatus <NUM> that is removable from the casing <NUM>, parts of the heating apparatus <NUM> may be easily repaired and replaced without the need to replace the entire device <NUM>.

In this example, the electrical contacts <NUM> comprise a pair of pins. The pins may be connectable to the casing <NUM> with a lockable coupling. The pins may be inserted into the side portion <NUM> of the casing <NUM> and locked in place via a small rotation or translation. As previously described in relation to the heating apparatus <NUM>, various connection arrangements may be used in order to provide both a strong mechanical connection and an electrical connection between the heating apparatus <NUM> and the casing <NUM> via the electrical contacts <NUM>.

The electrical contacts <NUM> are preferably located at a position on the insulator <NUM> that minimises heat flow between the openings 211a, 211b and the electrical contacts <NUM>. In this way, the electrical contacts <NUM> are made to the part of the exterior wall <NUM> that remains coolest during use of the aerosol generating device <NUM>. This reduces the transfer of heat between the insulator <NUM> and the casing <NUM>.

In the tube-shaped insulator <NUM> shown in <FIG>, the electrical contacts <NUM> may be located at a side of the insulator <NUM> that is spaced from the first opening 211a and the second opening 211b of the cavity <NUM>. For example, the electrical contacts <NUM> may be located at a side of the insulator <NUM> that is substantially equidistant from both the first opening 211a and the second opening 211b of the cavity <NUM>. At this location, the shortest distance between the electrical contacts <NUM> to either of the openings 211a, 211b is maximised, thereby reducing the transfer of heat from either of the openings 211a, 211b to the electrical contacts <NUM>. Alternatively, if one of the openings 211a, 211b is determined to produce more heat than the other (such as due to the insulative properties of the plug <NUM>), the position of the electrical contacts <NUM> may be adjusted accordingly (such as by moving them closer to the opening 211b with the plug <NUM>). In other words, the electrical contacts <NUM> are made to the coolest part of the exterior wall <NUM> during use, which reduces the amount of heat transferred from the insulator <NUM> to the casing <NUM> of the device <NUM>. In any of the embodiments described herein, the coolest part of the exterior wall <NUM> may be calculated such as by a computer simulation, in order to determine the optimum placement for the electrical contacts <NUM>.

It will be appreciated that the electrical contacts <NUM>, <NUM> described above may be located at other positions on the insulator <NUM>, <NUM> in order to provide the mechanical connection to the casing <NUM> of the device <NUM>. <FIG> show alternative embodiments of heating apparatuses <NUM>, <NUM> that may be used in the device <NUM>. The heating apparatus <NUM> is similar to the cup-shaped heating apparatus <NUM> described previously but differs in that the electrical contacts <NUM> are located at an end of the insulator <NUM> that is adjacent to the opening <NUM> of the cavity <NUM>. The heating apparatus <NUM> is similar to the cup-shaped heating apparatuses <NUM>, <NUM> described previously but differs in that that the electrical contacts <NUM> are located on the side of the insulator <NUM> near the opening <NUM> of the cavity <NUM>. This may enable easier inspection, and/or repair of the heating apparatus <NUM>, <NUM> and may be preferable for certain types of device <NUM>. As previously described, the electrical contacts <NUM>, <NUM> are mechanically connectable to the casing <NUM> of the device <NUM>, and preferably provide the only connection between the insulator <NUM>, <NUM> and the casing <NUM>.

While the foregoing is directed to exemplary embodiments of the present invention, it will be understood that the present invention is described herein purely by way of example, and modifications of detail can be made within the scope of the invention. Furthermore, one skilled in the art will understand that the present invention may not be limited by the embodiments disclosed herein, or to any details shown in the accompanying figures that are not described in detail herein or defined in the claims.

Claim 1:
An aerosol generating device (<NUM>), comprising:
an insulator (<NUM>; <NUM>; <NUM>; <NUM>) comprising an interior wall (<NUM>; <NUM>; <NUM>; <NUM>) and an exterior wall (<NUM>; <NUM>; <NUM>; <NUM>) that are separated from one another, a cavity (<NUM>; <NUM>; <NUM>; <NUM>) defined within the interior wall (<NUM>; <NUM>; <NUM>; <NUM>) in which an aerosol forming substrate (<NUM>) can be received, and a heater (<NUM>; <NUM>) positioned to heat the aerosol forming substrate (<NUM>) when it is received in the cavity (<NUM>; <NUM>; <NUM>; <NUM>);
a casing (<NUM>) that surrounds the insulator (<NUM>; <NUM>; <NUM>; <NUM>); and
electrical contacts (<NUM>; <NUM>; <NUM>; <NUM>) that are connected to the heater (<NUM>; <NUM>; <NUM>; <NUM>), wherein at least one of the electrical contacts (<NUM>; <NUM>; <NUM>; <NUM>) is mechanically connectable to the casing (<NUM>) in order to hold the insulator (<NUM>; <NUM>; <NUM>; <NUM>) in place.