Patent Publication Number: US-2023148656-A1

Title: An Aerosol Generating Article and An Aerosol Generating System

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to aerosol generating articles, and more particularly to an aerosol generating article for use with an aerosol generating device for heating the aerosol generating article to generate an aerosol for inhalation by a user. Embodiments of the present disclosure also relate to an aerosol generating system comprising an aerosol generating device and an aerosol generating article. 
     TECHNICAL BACKGROUND 
     Devices which heat, rather than bum, an aerosol generating substrate 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 substrate, including resistive heating and induction heating. 
     Whichever approach is used to heat the aerosol generating substrate, it can be convenient to provide the aerosol generating substrate in the form of an aerosol generating article that is configured for use with an aerosol generating device. Aerosol generating articles are known in the art and typically comprise an aerosol generating substrate positioned at a distal end of the aerosol generating article and a filter positioned at the proximal (mouth) end. 
     It is conceivable that a user may inadvertently attempt to ignite the aerosol generating article in a conventional manner, using a flame or other ignition source. There is, therefore, a need to provide an aerosol generating article, for use with an aerosol generating device, which has a reduced susceptibility to ignition using a flame or other ignition source. 
     SUMMARY OF THE DISCLOSURE 
     According to a first aspect of the present disclosure, there is provided an aerosol generating article comprising: 
     a wrapper; 
     an aerosol generating substrate positioned in the wrapper to form a rod having a mouth end and a distal end upstream of the mouth end; and 
     an airflow barrier positioned in the wrapper; 
     the airflow barrier comprising a deformable capsule which substantially prevents airflow from the distal end to the mouth end when in an undeformed state and which is deformable by a user into a deformed state which permits airflow from the distal end to the mouth end. 
     The aerosol generating article is configured for use with an aerosol generating device for heating the aerosol generating substrate, without burning the aerosol generating substrate, to volatise at least one component of the aerosol generating substrate and thereby generate a vapour which cools and condenses to form an aerosol for inhalation by a user of the aerosol generating 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. 
     By substantially preventing airflow from the distal end to the mouth end of the rod when a user draws on the mouth end, the undeformed airflow barrier reduces the likelihood of the user being able to ignite the aerosol generating substrate, for example using an external ignition source, such as a flame, applied to the distal end. This is because the airflow through the aerosol generating article is insufficient to permit ignition and/or sustain combustion of the aerosol generating substrate. 
     The aerosol generating substrate is typically positioned at the distal end of the rod. The aerosol generating article may include a filter positioned at the mouth end of the rod. The filter may, for example, comprise cellulose acetate fibres and/or paper. 
     The deformable capsule may have an outer dimension, e.g. an outer diameter, which is substantially equal to a diameter of the filter. The deformable capsule may have an outer dimension, e.g. an outer diameter, which is substantially equal to an inner diameter of the wrapper. 
     When the deformable capsule is in the undeformed state, the capsule may span an inner cross-section of the wrapper to substantially prevent airflow from the distal end to the mouth end. Since airflow between an outer surface of the capsule and an inner surface of the wrapper is substantially prevented, airflow through the aerosol generating substrate is reliably substantially prevented when the deformable capsule is in the undeformed state. 
     The deformable capsule may have a cross-sectional area which is at least 90% of the cross-sectional area of the filter, more preferably 95%, even more preferably between 98% and 100%. The cross-sectional area of the filter is meant to be the cross-sectional or surface area of the filter without considering the thickness of the wrapper (e.g. plug wrap). 
     The capsule may be configured to permit airflow from the distal end to the mouth end between an outer surface of the capsule and an inner surface of the wrapper when the capsule is in the deformed state. Airflow through the aerosol generating substrate is thereby readily permitted, allowing the aerosol generated during use of the aerosol generating article with an aerosol generating device to be inhaled by a user. 
     In a first example, the deformable capsule may be configured to be deformed from the undeformed state into the deformed state upon the application of a force by a user&#39;s fingers. The capsule can be readily and conveniently deformed by a user to permit airflow from the distal end to the mouth end when a user wishes to use the aerosol generating article with an aerosol generating device for the purpose of aerosol generation. The deformable capsule may have a crush strength of between 4.9 N and 24.5 N when in the undeformed state. A force within this range can be conveniently applied by a user&#39;s fingers, allowing the deformable capsule to be readily deformed from the undeformed state into the deformed state by a user without the need for a separate crushing tool. 
     In a second example, the deformable capsule may have a crush strength greater than 24.5 N, possibly between 25 N and 100 N, and preferably between 25 N and 50 N. Thus, the deformable capsule may be configured to be deformed from the undeformed state into the deformed state upon the application of a force greater than 24.5 N, possibly between 25 N and 100 N, and preferably between about 25 N and 50 N. In this example, the relatively high crush strength of the deformable capsule means that it cannot be crushed by a user&#39;s fingers, thus ensuring that the aerosol generating article is child proof The relatively high crush strength may also facilitate manufacture of aerosol generating articles according to the present disclosure, because the aerosol generating articles can be processed and manufactured using a conventional manufacturing machine without risk of the deformable capsule being crushed by the forces applied during processing and manufacture. This is the case even when the outer diameter of the deformable capsule is substantially equal to the diameter of the filter. 
     In this second example, a crushing tool may be needed to apply the necessary crushing force to the deformable capsule to deform the capsule from the undeformed state into the deformed state. The crushing tool may be configured for use specifically with the aerosol generating article. The crushing tool could be provided as part of an aerosol generating device, ensuring that the aerosol generating article can only be used with an aerosol generating device having the necessary crushing tool. 
     The deformable capsule may be substantially spherical when in the undeformed state. A spherical capsule may be easy to manufacture and may facilitate manufacture of aerosol generating articles according to the present disclosure because it can be readily processed using a conventional manufacturing machine. A spherical capsule may also be a particularly convenient shape to substantially prevent airflow through the aerosol generating article when the capsule is in the undeformed state. 
     The deformable capsule may be a crushable capsule. The use of a crushable capsule allows the capsule to be transformed from the undeformed state to the deformed state whilst remaining intact. 
     The deformable capsule may be a frangible capsule and may comprise a frangible shell. When a force is applied to the frangible capsule which exceeds its compressive strength, the frangible capsule breaks up into fragments, perforates or collapses. An enhanced airflow through the aerosol generating article may, therefore, be achieved through the use of a frangible capsule. 
     The deformable capsule may contain a flavourant which may be released upon deformation of the capsule from the undeformed state into the deformed state. The flavourant may be a liquid flavourant. By incorporating a flavourant into the deformable capsule, additional flavours may be provided to the user during use of the aerosol generating article in an aerosol generating device. The flavourant may be used to enhance the flavour(s) produced upon heating the aerosol generating substrate, or to provide a different flavour, including (but not limited to) menthol, mint or berry. 
     The frangible shell may be substantially impermeable when the capsule is in the undeformed state and the flavourant may be contained inside the impermeable shell. Thus, the flavourant may be preserved inside the capsule prior to use of the aerosol generating article, thereby preventing (or at least minimising) degradation of the flavourant and improving the shelf-life of the aerosol generating article. 
     The deformable capsule may comprise a layer or discrete pieces which may include a vapour cooling substance. The layer may be an outer layer of the capsule. The discrete pieces may be powder and the like contained inside the capsule and exposed to vapour when the capsule is crushed. The vapour cooling substance may comprise polylactic acid. The vapour cooling substance promotes cooling of the vapour or aerosol as it flows towards the mouth end of the rod to form an aerosol with suitable characteristics for inhalation by a user. 
     The deformable capsule may be positioned in the wrapper downstream of the aerosol generating substrate. The deformable capsule may be positioned in the wrapper upstream of the mouth end, and may be positioned upstream of the optional filter positioned at the mouth end. 
     The aerosol generating article may include a vapour cooling element positioned in the wrapper downstream of the aerosol generating substrate. The vapour cooling element promotes cooling of the vapour as it flows from the aerosol generating substrate towards the mouth end to form an aerosol with suitable characteristics for inhalation by a user. The deformable capsule may be positioned downstream of the vapour cooling element. Such positioning may help to improve flavour enhancement as the vapour or aerosol flows in a downstream direction from the vapour cooling element towards the mouth end. 
     The vapour cooling element may comprise a hollow paper tube which may have a thickness greater than a thickness of the wrapper. Manufacture of aerosol generating articles according to the present disclosure is thereby facilitated. 
     The aerosol generating substrate may comprise a non-liquid aerosol generating material, for example any type of solid or semi-solid material. Example types of aerosol generating substrate include powder, granules, pellets, shreds, strands, particles, gel, strips, loose leaves, cut leaves, cut filler, porous material, foam material or sheets. The aerosol generating substrate may comprise plant derived material and in particular, may comprise tobacco. It may advantageously comprise reconstituted tobacco. 
     The aerosol generating substrate may comprise a plug of aerosol generating material. That is, the aerosol generating substrate may comprise an aerosol generating plug. The aerosol generating substrate may comprise a tobacco plug. 
     The aerosol generating substrate 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 substrate may comprise an aerosol-former content of between approximately 5% and approximately 50% on a dry weight basis. In some embodiments, the aerosol generating substrate may comprise an aerosol-former content of between approximately 10% and approximately 20% on a dry weight basis, and possibly approximately 15% on a dry weight basis. 
     Upon heating, the aerosol generating substrate may release volatile compounds. The volatile compounds may include nicotine and/or flavour compounds such as tobacco flavouring. 
     The wrapper may comprise a material which is substantially non-electrically conductive and non-magnetically permeable and may, for example, comprise a paper wrapper. The use of a wrapper may facilitate manufacture and handing of the aerosol generating article and may enhance aerosol generation. 
     According to a second aspect of the present disclosure, there is provided an aerosol generating system comprising:
         an aerosol generating article according to the first aspect; and   an aerosol generating device including: a crushing tool configured to allow a user to apply a force to the deformable capsule to permit deformation of the capsule by the user from the undeformed state into the deformed state; and a heater for heating the aerosol generating substrate to generate an aerosol for inhalation by a user.       

     The aerosol generating article may be as defined above. As noted above, the crushing tool allows a user to apply the necessary crushing force to the deformable capsule to deform the capsule from the undeformed state into the deformed state and allows the capsule to be manufactured with a sufficiently high crush strength (above 24.5 N) that the aerosol generating article is child proof. 
     The crushing tool may comprise a user-operable lever and a crushing plate. The user-operable lever may be pivotally mounted on a device body or housing of the aerosol generating device and may be movable between a first position and a second position. Upon user operation to move the user-operable lever from the first position to the second position, the crushing plate may be correspondingly moved from a retracted position to an advanced position in which the crushing plate compresses the deformable capsule. 
     The user-operable lever and the crushing plate may be configured to provide a mechanical advantage, such that the force applied to the deformable capsule by the crushing plate is greater than the force applied by a user to the user-operable lever. The crushing tool thus allows a deformable capsule with a high crush strength (above 24.5 N) to be crushed with relative ease. 
     The user-operable lever may be biased to the first position. Thus, the crushing plate is similarly biased to the retracted position unless a force is applied by a user to the user-operable lever. 
     The heater may comprise a heating blade. 
     The heater may comprise a heating tube comprising a chamber dimensioned to at least receive the aerosol generating substrate of the aerosol generating article. 
     The heater may comprise a resistive heater. The resistive heater may comprise a resistive heating element, for example a resistive heating blade or a resistive heating tube. 
     The heater may comprise an induction heatable susceptor and the aerosol generating device may comprise an electromagnetic field generator, such as an induction coil, arranged to generate an alternating electromagnetic field for inductively heating the induction heatable susceptor. This arrangement provides a particularly convenient way to heat the aerosol generating substrate using induction heating. 
     The induction coil may comprise a Litz wire or a Litz cable. It will, however, be understood that other materials could be used. The induction coil may be substantially helical in shape and may extend around a heating chamber in which the aerosol generating article is positioned in use. The circular cross-section of a helical induction coil may, for example, facilitate the insertion of the aerosol generating article comprising the aerosol generating substrate and optionally one or more of said induction heatable susceptors, into the heating chamber and ensures uniform heating of the aerosol generating substrate. 
     The induction heatable 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 induction coil may be arranged to operate in use with a fluctuating electromagnetic field having a magnetic flux density of between approximately 20 mT and approximately 2.0 T at the point of highest concentration. 
     The aerosol generating device may include a power source and circuitry which may be configured to operate at a high frequency. The power source and circuitry may be configured to operate at a frequency of between approximately 80 kHz and 500 kHz, possibly between approximately 150 kHz and 250 kHz, and possibly at approximately 200 kHz. 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 induction heatable susceptor that is used. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is diagrammatic cross-sectional view of an aerosol generating article illustrating how airflow is substantially prevented through the article from a distal end to a mouth end by an airflow barrier; 
         FIG.  2    is a diagrammatic cross-sectional view of the aerosol generating article of  FIG.  1    illustrating how airflow is permitted from the distal end to the mouth end following deformation of the airflow barrier; 
         FIG.  3    is a diagrammatic cross-sectional view of a first example of an aerosol generating system comprising a first example of an electrically-operated aerosol generating device and the aerosol generating article illustrated in  FIGS.  1  and  2   ; 
         FIG.  4    is a diagrammatic cross-sectional view of a second example of an aerosol generating system comprising a second example of an electrically-operated aerosol generating device and the aerosol generating article illustrated in  FIGS.  1  and  2   ; and 
         FIG.  5    is a diagrammatic cross-sectional view of part of a third example of an aerosol generating system comprising a third example of an electrically-operated aerosol generating device and the aerosol generating article illustrated in  FIGS.  1  and  2   . 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Embodiments of the present disclosure will now be described by way of example only and with reference to the accompanying drawings. 
     Referring initially to  FIGS.  1  and  2   , there is shown diagrammatically a first example of an aerosol generating article  10 . The aerosol generating article  10  is elongate and substantially cylindrical and is of a so-called “stick” type. Airflow through the aerosol generating article  10  is from left to right as viewed in  FIG.  2   , from a distal (or upstream) end  12  to a mouth (or downstream) end  14  as denoted by the arrows. 
     The aerosol generating article  10  comprises the following elements arranged sequentially and in co-axial alignment in a downstream direction, in other words from the distal end  12  to the mouth end  14 : an aerosol generating substrate  16 , an optional vapour cooling element  18 , an airflow barrier  20  (e.g. deformable capsule  26 ) and an optional filter  22 , for example comprising cellulose acetate fibres. The elements are all assembled inside a wrapper  24  to form a rod, and the wrapper  24  holds the elements in position to form the aerosol generating article  10 . The wrapper  24  is substantially non-electrically conductive and non-magnetically permeable, and typically comprises a paper wrapper, e.g., formed of cigarette paper. 
     The aerosol generating substrate  16  comprises a solid or semi-solid material (i.e. a non-liquid material) and may comprise plant derived material, and in particular tobacco. The aerosol generating substrate  16  typically comprises a tobacco plug. The aerosol generating substrate  16  may include an aerosol-former, such as glycerine or propylene glycol, to facilitate the generation of a vapour or aerosol when heated. 
     The vapour cooling element  18  typically comprises a hollow paper tube  18   a  having a thickness which is greater than the thickness of the paper wrapper  24 . As heated vapour flows through the vapour cooling element  18  in the downstream direction, from the aerosol generating substrate  16  towards the mouth end  14 , the vapour cools and condenses to form an aerosol with suitable characteristics for inhalation by a user. The vapour cooling element  18  (e.g. hollow paper tube  18   a ) may contact the aerosol generating substrate  16  at a first end and/or the airflow barrier  20  (e.g. deformable capsule  26 ) at a second end. Ventilation may be provided through the hollow paper tube  18   a  and wrapper  24  such as by a multitude of perforations. 
     The airflow barrier  20  comprises a deformable capsule  26  which can be deformed by a user from an initially undeformed state as shown in  FIG.  1    into a deformed state as schematically shown in  FIG.  2   . Note that the deformed state shown in  FIG.  2    is highly schematic, and that the capsule  26  may simply be crushed or may break into many parts when it is deformed by a user. When the capsule  26  is in the undeformed state shown in  FIG.  1   , the capsule  26  prevents airflow from the distal end  12  to the mouth end  14  of the aerosol generating article  10  through the aerosol generating substrate  16 , as denoted schematically by the arrows in  FIG.  1   . When the capsule  26  is in the deformed state shown in  FIG.  2   , the capsule  26  permits airflow from the distal end  12  to the mouth end  14  of the aerosol generating article  10  through the aerosol generating substrate  16 , as denoted schematically by the arrows in  FIG.  2   . 
     In the illustrated example, the deformable capsule  26  is substantially spherical when in the undeformed state shown in  FIG.  1    and has an outer diameter which is substantially equal to an inner diameter of the wrapper  24  and to a diameter of the filter  22 . When the deformable capsule  26  is in the undeformed state, it spans the cross-section of an airflow channel  27  defined by the paper wrapper  24  and has a transverse cross-sectional area which is substantially equal to the free cross-section of the interior of the paper wrapper  24 . The airflow channel  27  defined by the paper wrapper  24  is, thus, substantially occluded (i.e. blocked) to substantially prevent or limit air flow between an outer surface of the deformable capsule  26  and an inner surface of the paper wrapper  24 . Airflow from the distal end  12  to the mouth end  14  of the aerosol generating article  10  is thereby substantially prevented or limited, thereby creating a high resistance to draw when the deformable capsule  26  is in the undeformed state. 
     Prior to use of the aerosol generating article  10  with an electrically-operated aerosol generating device, the deformable capsule  26  must be deformed to transform it from the undeformed state shown in  FIG.  1    into the deformed state shown in  FIG.  2   . As will be apparent from  FIG.  2   , when the deformable capsule  26  is in the deformed state, the airflow channel  27  is no longer completely occluded and air can flow along the airflow channel  27 , for example between the outer surface of the deformable capsule  26  and the inner surface of the paper wrapper  24 . Airflow from the distal end  12  to the mouth end  14  of the aerosol generating article  10  is, thereby, permitted when the deformable capsule  26  is in the deformed state, enabling the aerosol generating article  10  to be used with an electrically-operated aerosol generating device. 
     The deformable capsule  26  can be a crushable capsule as illustrated in  FIGS.  1  and  2   , such that the capsule  26  remains intact or perforates when it is crushed to transform it from the undeformed state into the deformed state. In another example, the deformable capsule  26  can be a frangible capsule comprising a frangible shell  28 . When a force is applied to the capsule  26  which exceeds its compressive strength, the frangible capsule breaks up into fragments, thus allowing air to flow through the airflow channel  27 . 
     The deformable capsule  26  can contain a flavourant  23  that is released upon deformation of the capsule  26  to enhance or modify the flavour of the aerosol delivered to the user when the aerosol generating article  10  is used with an electrically-operated aerosol generating device. The flavourant  23  can be a liquid flavourant  23  and, in this case, it is preferred that the deformable capsule  26  comprises an impermeable shell  28 . The impermeable shell  28  retains the flavourant  23  inside the capsule  26  when it is in the undeformed state. The impermeable shell  28  ruptures or bursts when the capsule  26  is deformed, thereby releasing the flavourant  23 . 
     In order to further promote the cooling of heated vapour as it flows from the aerosol generating substrate  16  towards the mouth end  14 , the deformable capsule  26  can comprise an outer layer  29  including a vapour cooling substance  25 . The vapour cooling substance  25  may, for example, comprise a polylactic acid although it will be understood that other vapour cooling substances such as cooling liquid may be used. 
     In order to transform the deformable capsule  26  from the undeformed state shown in  FIG.  1    into the deformed state shown in  FIG.  2   , it is necessary to apply a compressive force to the deformable capsule  26  which exceeds the crush strength of the capsule  26 . In a first embodiment, the deformable capsule  26  has a crush strength of between about 4.9 N and about 24.5 N. With a crush strength in this range, the deformable capsule  26  can be transformed from the undeformed state into the deformed state upon the application of a compressive force by a user&#39;s fingers as denoted by the arrows A in  FIG.  1   , thereby enabling the deformable capsule  26  to be readily and conveniently deformed by a user without the need for a separate crushing tool. In a second embodiment, the deformable capsule  26  has a crush strength greater than 24.5 N, possibly between 25 N and 100 N, and preferably between 25 N and 50 N. With a crush strength in these ranges, the deformable capsule  26  cannot be deformed easily upon the application of a compressive force by a user&#39;s fingers, thereby ensuring that the aerosol generating article  10  is child proof. Instead, a separate crushing tool must be used to apply the required compressive force to the capsule  26  to deform it. An example of a suitable crushing tool will be described later in this specification, with reference to  FIG.  5   . 
     Referring now to  FIG.  3   , there is shown diagrammatically a first example of an aerosol generating system  1 . The aerosol generating system  1  comprises a first example of an electrically-operated aerosol generating device  30  and an aerosol generating article  10  as described above. The aerosol generating device  30  has a proximal end  32  and a distal end  34  and comprises a device body  36  which includes a power source  38  and a controller  40  which may be configured to operate at high frequency. The power source  38  typically comprises one or more batteries which could, for example, be inductively rechargeable. 
     The aerosol generating device  30  comprises a substantially cylindrical heating chamber  42  having air inlets  42   a.  The heating chamber  42  is positioned at the proximal end  32  of the aerosol generating device  30  and is arranged to receive the substantially cylindrical aerosol generating article  10 . The aerosol generating device  30  includes a plurality of air inlets  44  formed in the device body  36  which deliver air to the heating chamber  42  via the air inlets  42   a.    
     The aerosol generating article  10  is positioned in the heating chamber  42  by inserting the distal end  12  into the heating chamber  42  via an opening  46 . The heating chamber  42  and aerosol generating article  10  are dimensioned so that the mouth end  14 , and in particular the filter  22 , projects from the heating chamber  42  at the proximal end  32  of the aerosol generating device  30 . Prior to inserting the aerosol generating article  10  into the heating chamber  42 , a compressive force is applied to the deformable capsule  26  in the manner described above to transform it from the undeformed state into the deformed state, and thereby allow air to flow from the air inlets  44 ,  42   a  and through the aerosol generating article  10 . 
     The aerosol generating device  30  comprises a resistive heating element  48  mounted on the device body  36  so that it projects into the heating chamber  42 . Thus, the heating element  48  is inserted into the aerosol generating substrate  16  during insertion of an aerosol generating article  10  into the heating chamber  42  by a user. For example, the heating element  48  could be a blade or an elongate pin which penetrates the aerosol generating substrate  16  as the aerosol generating article  10  is inserted into the heating chamber  42 . 
     During operation of the aerosol generating device  30 , electrical energy is supplied by the power source  38  to the resistive heating element  48  and the resistive heating element  48  is thereby heated. The heat is transferred from the resistive heating element  48  to the aerosol generating substrate  16 , causing it to heat up without burning and thereby produce a vapour. The vaporisation of the aerosol generating substrate  16  is facilitated by the addition of air from the surrounding environment through the air inlets  44 ,  42   a  or the opening  46 . The vapour generated by heating the aerosol generating substrate  16  cools and condenses as it flows through airflow channel  27  and the vapour cooling element  18 . In examples in which the deformable capsule  26  comprises a vapour cooling substance  25  as described above, further cooling takes places as the vapour or aerosol flows around the deformed capsule  26 . The resultant aerosol finally passes through the filter  22 , and is inhaled by a user. It will be understood that the flow of air through the aerosol generating article  10 , i.e. from the air inlets  44 ,  42   a  or the opening  46 , through the airflow channel  27  and through the filter  22 , is aided by negative pressure created by a user drawing air from the outlet side of the device  10  through the filter  22 . 
     Referring now to  FIG.  4   , there is shown diagrammatically a second example of an aerosol generating system  2 . The aerosol generating system  2  is similar to the aerosol generating system  1  described above with reference to  FIG.  3   , and corresponding components are identified using the same reference numerals. 
     The aerosol generating system  2  comprises a second example of an electrically-operated aerosol generating device  50  and an aerosol generating article  10  as described above. 
     The aerosol generating device  50  comprises a magnetic field generator  52  for generating an electromagnetic field. The magnetic field generator  52  comprises a substantially helical induction coil  54 . The induction coil  54  has a circular cross-section and extends around the substantially cylindrical heating chamber  42 . The induction coil  54  can be energised by the power source  38  and controller  40 . The controller  40  includes, amongst other electronic components, an inverter which is arranged to convert a direct current from the power source  38  into an alternating high-frequency current for the induction coil  54 . 
     The aerosol generating system  2  further includes an induction heatable susceptor (not shown) located proximate, or in contact with, the aerosol generating substrate  16 . The induction heatable susceptor may, for example, comprise a blade-shaped or pin-shaped or ring-shaped susceptor mounted on the device body in the same way as the resistive heating element  48  illustrated in  FIG.  3   . The induction heatable susceptor may alternatively comprise a particulate susceptor material which is dispersed throughout the aerosol generating substrate  16  during manufacture and assembly of the aerosol generating article  10 . 
     Irrespective of the particular configuration of the induction heatable susceptor, and as will be understood by one of ordinary skill in the art, when the induction coil  54  is energised during use of the aerosol generating system  2 , an alternating and time-varying electromagnetic field is produced. This couples with the induction heatable susceptor and generates eddy currents and/or magnetic hysteresis losses in the susceptor causing it to heat up. The heat is then transferred from the induction heatable susceptor to the aerosol generating substrate  16 , for example by conduction, radiation and convection, to heat the aerosol generating substrate  16  without burning and thereby produce a vapour. The flow of vapour and aerosol through the aerosol generating device  50  is the same as that described above in connection with the aerosol generating device  30  of  FIG.  3   . 
     Referring now to  FIG.  5   , there is shown diagrammatically a third example of part of an aerosol generating system  3 . The aerosol generating system  3  is similar to the aerosol generating systems  1 ,  2  described above with reference to  FIGS.  3  and  4   , and corresponding components are identified using the same reference numerals. 
     The aerosol generating system  3  comprises an aerosol generating device  60  for receiving the aerosol generating article  10 . It will be understood by one of ordinary skill in the art that only part of the aerosol generating device  60  is shown in  FIG.  5   , and in particular that the power source and controller described above are not shown. The aerosol generating device  60  comprises a cup-shaped heater  62  which receives the distal end  12  of the aerosol generating article  10  when the aerosol generating article  10  is inserted into the aerosol generating device  60 . The cup-shaped heater  62  can be a resistive heater as described above with reference to  FIG.  3    or an induction heatable susceptor as described above with reference to  FIG.  4    or a metal cup onto which a thin film heater is affixed such as described in WO 2020/074611 A1 entitled “Aerosol generation device and heating chamber therefor”. In all cases, it will be understood that during operation of the aerosol generating device  60 , heat is transferred from the cup-shaped heater  62  to the adjacent aerosol generating substrate  16  to thereby heat the aerosol generating substrate  16  without burning to produce a vapour. 
     The aerosol generating device  60  is particularly suitable for use with an aerosol generating article  10  in which the deformable capsule  26  has a high crush strength, for example above  24 . 5  N as described above, and which cannot, therefore, be crushed by a compressive force applied directly by a user&#39;s fingers. Accordingly, the aerosol generating device  60  includes a crushing tool  64  that is configured to allow a user to apply a suitable crushing force to the deformable capsule  26  to deform the capsule  26  from the undeformed state shown in  FIGS.  1  and  5    into the deformed state shown in  FIG.  2   . As will be understood by one of ordinary skill in the art, deformation of the capsule  26  takes place after the aerosol generating article  10  has been inserted into the aerosol generating device  60 . 
     In the illustrated example, the crushing tool  64  comprises a pair of user-operable levers  66  and associated crushing plates  68  positioned at diametrically opposite locations on the device body  36 . Each of the user-operable levers  66  is pivotally mounted on the device body  36  by a pivotal mounting  70  and is movable by a user towards the device body  36  in the direction of the arrows B from a first position shown in  FIG.  5    to a second position. 
     The aerosol generating device  60  is dimensioned so that the user-operable levers  66  can be grasped by a user and moved simultaneously from the first position to the second position in the direction of the arrows B. Upon movement of the user-operable levers  66  by a user from the first position to the second position, the associated crushing plates  68  are correspondingly moved about the pivotal mounting  70  in the direction of the arrows C from a retracted position shown in  FIG.  5    to an advanced position in which the crushing plates  68  contact the deformable capsule  26 . As the crushing plates  68  move towards each other in the direction of the arrows C and contact the deformable capsule  26 , the deformable capsule  26  is crushed between the crushing plates  68  and transformed from the undeformed state shown in  FIGS.  1  and  5    into the deformed state shown in  FIG.  2   . 
     The user-operable levers  66  are spring-biased to the first position. Thus, when the user-operable levers  66  are released by a user, the crushing plates  68  are correspondingly biased to the retracted position shown in  FIG.  5   . 
     The user-operable levers  66  and the crushing plates  68  are configured to provide a mechanical advantage. Accordingly, the force applied to the deformable capsule  26  by the crushing plates  68  is greater than the force applied by a user to the user-operable levers  66 , meaning that a deformable capsule  26  with a high crush strength can be easily crushed using the crushing tool  64 . 
     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. 
     Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like, are to be construed in an inclusive as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.