AEROSOL-GENERATING DEVICE COMPRISING A COVER ELEMENT SENSOR

Abstract

An aerosol-generating device is provided, including: a housing; a cavity to receive an aerosol-generating article; an aperture at least partially defined by the housing and disposed at an end of the cavity for insertion of the article through the aperture; a cover element to move relative to the housing between a closed position and an open position; a sensor to provide an electrical signal indicative of a position of the cover element with respect to the aperture and including an optical sensor; and an indicator element to move relative to the sensor when the cover element is moved between the closed and the open positions and including an optical surface, the signal being determined by a position of the indicator element relative to the sensor, and the optical surface being configured to move relative to the optical sensor when the cover element moves between the closed and the open positions.

Claims

1.-18. (canceled)

19. An aerosol-generating device, comprising: a housing; a cavity configured to receive an aerosol-generating article; an aperture at least partially defined by the housing, wherein the aperture is disposed at an end of the cavity and configured for insertion of the aerosol-generating article into the cavity through the aperture; a cover element configured to move, with respect to the housing, between a closed position in which the cover element at least partially covers the aperture and an open position in which the aperture is at least partially uncovered; a sensor configured to provide an electrical signal indicative of a position of the cover element with respect to the aperture; and an indicator element configured to move, with respect to the sensor, when the cover element is moved between the closed position and the open position, wherein the electrical signal provided by the sensor is determined by a position of the indicator element relative to the sensor, the indicator element comprising an optical surface, wherein the sensor comprises an optical sensor comprising a light transmitter and a light receiver, and wherein the optical surface is configured to move, with respect to the optical sensor when the cover element moves between the closed position and the open position.

20. The aerosol-generating device according to claim 19, wherein the indicator element is further configured to move with respect to the sensor and the cover element, the aerosol-generating device further comprising a mechanical linkage configured to translate movement of the cover element between the closed position and the open position into movement of the indicator element with respect to the sensor.

21. The aerosol-generating device according to claim 20, wherein the cover element is rotatable with respect to the housing between the closed position and the open position, and wherein the mechanical linkage comprises at least one of a cam and a gear.

22. The aerosol-generating device according to claim 21, wherein the cover element comprises a cover portion and a shaft portion extending from the cover portion, wherein the cover portion is configured to at least partially cover the aperture when the cover element is in the closed position, and wherein the shaft portion is received within the housing.

23. The aerosol-generating device according to claim 22, wherein the mechanical linkage comprises at least one of a cam and a gear connected to the shaft portion of the cover element.

24. The aerosol-generating device according to claim 23, wherein the indicator element further comprises at least one of a cam, a cam follower, and a gear.

25. The aerosol-generating device according to claim 19, wherein the indicator element further comprises a magnetic material, and wherein the sensor further comprises at least one of a reed switch and a Hall effect sensor.

26. The aerosol-generating device according to claim 19, wherein the optical surface has a planar shape.

27. The aerosol-generating device according to claim 26, wherein the optical surface is further configured to move between a first rotational position when the cover element is in the closed position and a second rotational position when the cover element is in the open position.

28. The aerosol-generating device according to claim 27, wherein the indicator element further comprises a biasing element configured to bias the optical element towards the first rotational position or the second rotational position.

29. The aerosol-generating device according to claim 27, wherein the optical sensor further comprises a planar sensor surface, and wherein the optical surface is further configured to extend parallel with the planar sensor surface when the optical surface is in the first rotational position or the second rotational position.

30. The aerosol-generating device according to claim 19, wherein the housing comprises a first housing and a second housing configured for removable attachment to the first housing, wherein the aperture is at least partially defined by the second housing, and wherein the cover element is further configured to move, with respect to the second housing, between the closed position and the open position.

31. The aerosol-generating device according to claim 30, wherein the sensor is disposed within the first housing.

32. The aerosol-generating device according to claim 31, wherein the sensor is further configured to provide at least one of an electrical signal indicative of the second housing being detached from the first housing and an electrical signal indicative of the second housing being attached to the first housing.

33. The aerosol-generating device according to claim 19, further comprising a controller and an electrical heater configured to heat the aerosol-generating article when the aerosol-generating article is received within the cavity, wherein the controller is configured to control a supply of power to the electrical heater in response to a signal received from the sensor.

34. An aerosol-generating system, comprising an aerosol-generating device according to claim 19 and an aerosol-generating article, wherein the aerosol-generating article comprises an aerosol-forming substrate.

Description

[0173] The invention will now be further described, by way of example only, with reference to the accompanying drawings in which:

[0174] FIG. 1 shows a cross-sectional view of an aerosol-generating device according to an embodiment of the present invention;

[0175] FIG. 2 shows a cross-sectional view of the aerosol-generating device of FIG. 1 with the second housing moved relative to the first housing;

[0176] FIGS. 3 to 5 illustrate the rotational movement of the cover element of the aerosol-generating device of FIGS. 1 and 2;

[0177] FIG. 6 shows an exploded perspective view of the mechanical linkage of the aerosol-generating device of FIGS. 1 and 2;

[0178] FIGS. 7 to 18 illustrate the operation of the mechanical linkage of FIG. 6;

[0179] FIGS. 19 and 20 illustrate a first alternative arrangement of the indicator element of the aerosol-generating device of FIGS. 1 and 2;

[0180] FIGS. 21 and 22 illustrate a second alternative arrangement of the indicator element of the aerosol-generating device of FIGS. 1 and 2;

[0181] FIG. 23 shows an exploded perspective view of an alternative arrangement of the mechanical linkage of the aerosol-generating device of FIGS. 1 and 2;

[0182] FIGS. 24 to 33 illustrate the operation of the mechanical linkage of FIG. 23;

[0183] FIG. 34 shows an exploded perspective view of a further alternative arrangement of the mechanical linkage of the aerosol-generating device of FIGS. 1 and 2;

[0184] FIG. 35 shows a perspective view of the mechanical linkage of FIG. 34; and

[0185] FIG. 36 shows a cross-sectional view of an aerosol-generating article for use with the aerosol-generating device of FIGS. 1 and 2.

[0186] FIGS. 1 and 2 show a cross-sectional view of an aerosol-generating device 10 according to an embodiment of the present invention. The aerosol-generating device 10 comprises a housing 12 comprising a first housing 14 and a second housing 16. The second housing 16 is slidable with respect to the first housing 14 between a compressed position shown in FIG. 2 and an expanded position shown in FIG. 1. The second housing 16 may also be detached from the first housing 14.

[0187] The aerosol-generating device 10 also comprises a controller 18 and a power supply 20 positioned within the first housing 14, and a heater 22 extending from an end of the first housing 14. The power supply 20 is an electrical power supply comprising a rechargeable battery. The heater 22 is an electrical heater comprising a resistive heating element 24. During use, the controller 18 supplies power from the power supply 20 to the resistive heating element 24 to resistively heat the heater 22.

[0188] Positioned on the first housing 14 next to the heater 22 are a sensor 26 and a first magnet 28. The sensor 26 is an optical sensor comprising a light transmitter and a light receiver. The light transmitter is an infrared light emitting diode and the light receiver is a photodiode. The photodiode is sensitive to infrared light transmitted from the infrared light emitting diode. An optical window 30 overlies the sensor 26, wherein the optical window is transparent to the infrared light transmitted from the infrared light emitting diode.

[0189] The second housing 16 defines a cavity 32 for receiving an aerosol-generating article and an aperture 34 positioned at an end of the cavity 32. When the second housing 16 is attached to the first housing 14, the heater 22 extends into the cavity 32 via a heater opening 36 defined by the second housing 16. An air inlet 38 is formed by a gap between the first housing 14 and the second housing 16. The air inlet 38 is in fluid communication with the cavity 32 via an airflow opening 40 defined by the second housing 16.

[0190] When an aerosol-generating article is received within the cavity 32, the aerosol-generating article and the aerosol-generating device 10 together form an aerosol-generating system. During use, the heater 22 heats the aerosol-generating article received within the cavity 32 to generate an aerosol. When a user draws on the aerosol-generating article, air is drawn into the aerosol-generating device 10 via the air inlet 38 and into the cavity 32 through the airflow opening 40. The air then flows through the aerosol-generating article to deliver the generated aerosol to the user.

[0191] The aerosol-generating device 10 also comprises a cover element 42 comprising a cover portion 44 overlying an end wall 46 of the second housing 16 and a shaft portion 48 extending through the end wall 46. The cover element 42 is rotatable between a closed position in which the cover portion 44 covers the aperture 34 and an open position in which the cover portion 44 does not cover the aperture 34. The closed position is shown in FIG. 2 and the open position is shown in FIG. 1. FIGS. 3 to 5 illustrate the rotation of the cover element 42 from the closed position (FIG. 3) to the open position (FIG. 5).

[0192] Positioned within the second housing 16 is a mechanical linkage 50 arranged to interact with the shaft portion 48 of the cover element 42. An exploded view of the mechanical linkage 50 is shown in FIG. 6.

[0193] The mechanical linkage 50 comprises a chassis 152 attached to the second housing 16 by a screw 54. Mounted onto the chassis 152 is second magnet 56 arranged to interact with the first magnet 28 on the first housing 14. In particular, the first and second magnets 28, 56 are magnetically attracted to each other to facilitate attachment of the second housing 16 to the first housing 14.

[0194] Also mounted on the chassis 152 are a latching mechanism 158 and a closing mechanism 159 comprising a bushing 160, a cam 162, a cam follower 164, a cam follower biasing spring 165, a torsion spring 166, a release pin 168 and a release pin biasing spring 169.

[0195] The cam 162 is connected to an end of the shaft portion 48 of the cover element 42 by an interference fit. Therefore, when the cover element 42 is rotated between the closed and open positions, the cam 162 is also rotated. The bushing 160 and the torsion spring 166 are positioned coaxially about the shaft portion 48 of the cover element 42.

[0196] The cam follower 164 is slidably received within the chassis 152 and engages a first cam surface 163 formed on the cam 162. Therefore, when the cam 162 rotates during rotation of the cover element 42, the cam follower 164 moves up and down within the chassis 152. An indicator element 74 comprising an optically reflective aluminium layer is positioned on a bottom surface of the cam follower 164. When the cam follower 164 moves up and down within the chassis 152, the sensor 26 senses a change in distance between the sensor 26 and the indicator element 74. Based on the sensed distance between the sensor 26 and the indicator element 74, the sensor 26 provides a signal to the controller 18 indicative of whether the cover element 42 is in the closed position or the open position.

[0197] If the signal from the sensor 26 is indicative of the cover element 42 being in the closed position, it is assumed that an aerosol-generating article is not received within the cavity 32 and the controller 18 will not supply power from the power supply 20 to the heater 22 for heating an aerosol-generating article.

[0198] If the signal from the sensor 26 is indicative of the cover element 42 being in the open position, an aerosol-generating article may be received within the cavity 32 and the controller 18 may supply power from the power supply 20 to the heater 22 for heating an aerosol-generating article.

[0199] If the sensor 26 cannot detect the indicator element 74 it is assumed that the second housing 16 has been detached from the first housing 14. In this case, the sensor 26 provides a signal to the controller 18 indicative of the second housing 16 being detached from the first housing 14 and the controller 18 will prevent the supply of power to the heater 22.

[0200] The operation of the latching mechanism 158 and the closing mechanism 159 will now be described with reference to FIGS. 7 to 18.

[0201] FIG. 7 shows the cover element 42 in the closed position. When the cover element 42 is in the closed position, the cam follower 164 is biased into a lowered position by the cam follower biasing spring 165 and the release pin 168 is maintained in a raised position by the first housing 14, as shown in FIG. 8.

[0202] When the cover element 42 is rotated towards the open position, the rotation of the cam 162 raises the cam follower 164 into a raised position against the force of the cam follower biasing spring 165 and loads the torsion spring 166. As shown in FIG. 10, the release pin 168 remains in its raised position.

[0203] When the cover element 42 reaches the open position, the cam follower 164 is received within a detent 171 defined by the first cam surface 163 of the cam 162, as shown in FIG. 11. When the cam follower 164 is received within the detent 171, the torsion spring 166 is unable to rotate the cam 162 and the cover element 42 back towards the closed position. The release pin 168 remains in its raised position, as shown in FIG. 12.

[0204] When the second housing 16 is moved away from the first housing 14, the release pin biasing spring 169 pushed the release pin 168 into a lowered position, as shown in FIGS. 13 and 14. During the motion of the release pin 168 into its lowered position, a projection 173 on the release pin 168 engages a second cam surface 175 defined by the chassis 152, which rotates the release pin 168 to position the projection 173 underneath the cam follower 164.

[0205] When the second housing 16 is moved towards the first housing 14, the first housing 14 pushes the release pin 168 upwards against the force of the release pin biasing spring 169. As the release pin 168 moves upwards, the projection 173 on the release pin 168 engages the cam follower 164 and pushes the cam follower 164 towards its raised position, as shown in FIGS. 15 and 16. As the cam follower 164 is pushed towards its raised position, the cam follower 164 is disengaged from the detent 171 defined by the first cam surface 163 of the cam 162.

[0206] When the cam follower 164 is disengaged from the detent 171 defined by the first cam surface 163 of the cam 162, the torsion spring 166 rotates the cam 162 and returns the cover element 42 to the closed position, as shown in FIG. 17. At the same time, the first housing 14 continues to push the release pin 168 upwards and the projection 173 on the release pin 168 engages a third cam surface 177 defined by the second housing 16. The third cam surface 177 rotates the projection 173 away from the cam follower 164 so that the release pin 168 disengages the cam follower 164, as shown in FIG. 18. At this point, the latching mechanism 158 and the closing mechanism 159 have returned to the initial configurations shown in FIGS. 7 and 8.

[0207] FIGS. 19 and 20 illustrate a first alternative arrangement of the indicator element 74. In the arrangement shown in FIGS. 19 and 20, the indicator element 74 comprises a substrate portion 75 connected to the cam follower 164 by a pivot 77. The indicator element 74 also comprises an optically reflective aluminium layer positioned on a planar surface of the substrate portion 75 to form an optical surface 79 having a planar shape. The indicator element 74 also comprises a biasing element 81 in the form of a spring positioned between a free end of the substrate portion 75 and the bottom surface of the cam follower 164.

[0208] When the cam follower 164 is in the raised position shown in FIG. 19, when the cover element 42 is in the open position, the biasing element 81 pushes the free end of the substrate portion 75 away from the bottom surface of the cam follower 164 so that the optical surface 79 is positioned in a first rotational position with respect to the sensor 26. When the optical surface 79 is in the first rotational position, light emitted from the light transmitter 83 of the sensor 26 is reflected away from the light receiver 85 of the sensor 26. Therefore, when the optical surface 79 is in the first rotational position, the light receiver 85 of the sensor 26 provides a low or null signal indicative of the cover element 42 being in the open position.

[0209] When the cam follower 164 moves into the lowered position shown in FIG. 20, when the cover element 42 is in the closed position, the free end of the substrate portion 75 abuts the optical window 30 and overcomes the biasing force provided by the biasing element 81 so that the optical surface 79 is positioned in a second rotational position with respect to the sensor 26. When the optical surface 79 is in the second rotational position, light emitted from the light transmitter 83 of the sensor 26 is reflected towards the light receiver 85 of the sensor 26. Therefore, when the optical surface 79 is in the second rotational position, the light receiver 85 of the sensor 26 provides a high signal indicative of the cover element 42 being in the closed position.

[0210] FIGS. 21 and 22 illustrate a second alternative arrangement of the indicator element 74. In the arrangement shown in FIGS. 21 and 22, the indicator element 74 comprises a substrate portion 175 adhered to a bottom surface of the cam follower 164. The substrate portion 175 comprises an elastically compressible foam and has a wedge-shape. The indicator element 74 also comprises an optically reflective aluminium layer positioned on a planar surface of the substrate portion 175 to form an optical surface 179 having a planar shape.

[0211] When the cam follower 164 is in the raised position shown in FIG. 21, when the cover element 42 is in the open position, the wedge-shape of the substrate portion 175 positions the optical surface 179 in a first rotational position with respect to the sensor 26. When the optical surface 179 is in the first rotational position, light emitted from the light transmitter 83 of the sensor 26 is reflected away from the light receiver 85 of the sensor 26. Therefore, when the optical surface 179 is in the first rotational position, the light receiver 85 of the sensor 26 provides a low or null signal indicative of the cover element 42 being in the open position.

[0212] When the cam follower 164 moves into the lowered position shown in FIG. 22, when the cover element 42 is in the closed position, the substrate portion 175 is elastically compressed into a planar shape against the optical window 30 so that the optical surface 179 is positioned in a second rotational position with respect to the sensor 26. When the optical surface 179 is in the second rotational position, light emitted from the light transmitter 83 of the sensor 26 is reflected towards the light receiver 85 of the sensor 26. Therefore, when the optical surface 179 is in the second rotational position, the light receiver 85 of the sensor 26 provides a high signal indicative of the cover element 42 being in the closed position.

[0213] FIG. 23 shows an exploded view of an alternative arrangement of the mechanical linkage 50.

[0214] The alternative mechanical linkage comprises a chassis 252 attached to the second housing 16 by a screw 54. Mounted onto the chassis 252 is second magnet 56 arranged to interact with the first magnet 28 on the first housing 14. In particular, the first and second magnets 28, 56 are magnetically attracted to each other to facilitate attachment of the second housing 16 to the first housing 14.

[0215] Also mounted on the chassis 252 are a latching mechanism 258 and a closing mechanism 259 comprising a washer 260, a first gear 262, a geared cam follower 264, a cam follower biasing spring 265, a release element 268 and a release element biasing spring 269.

[0216] The washer 260 is formed from a low friction material to facilitate rotation of the first gear 262 on the chassis 252. The first gear 262 is connected to an end of the shaft portion 48 of the cover element 42 by an interference fit. Therefore, when the cover element 42 is rotated between the closed and open positions, the first gear 262 is also rotated.

[0217] The geared cam follower 264 is slidably received within the chassis 252 and engages the first gear 262 and a first cam surface 263 formed by the chassis 252. Therefore, when the first gear 262 rotates during rotation of the cover element 42, the geared cam follower 264 moves up and down within the chassis 252. An indicator element 74 comprising an optically reflective aluminium layer is positioned on a bottom surface of the geared cam follower 264. When the geared cam follower 264 moves up and down within the chassis 252, the sensor 26 senses a change in distance between the sensor 26 and the indicator element 74. Based on the sensed distance between the sensor 26 and the indicator element 74, the sensor 26 provides a signal to the controller 18 indicative of whether the cover element 42 is in the closed position or the open position. It will be appreciated that the indicator element 74 may be substituted with either of the alternative arrangements described herein with reference to FIGS. 19 to 22.

[0218] If the signal from the sensor 26 is indicative of the cover element 42 being in the closed position, it is assumed that an aerosol-generating article is not received within the cavity 32 and the controller 18 will not supply power from the power supply 20 to the heater 22 for heating an aerosol-generating article.

[0219] If the signal from the sensor 26 is indicative of the cover element 42 being in the open position, an aerosol-generating article may be received within the cavity 32 and the controller 18 may supply power from the power supply 20 to the heater 22 for heating an aerosol-generating article.

[0220] If the sensor 26 cannot detect the indicator element 74 it is assumed that the second housing 16 has been detached from the first housing 14. In this case, the sensor 26 provides a signal to the controller 18 indicative of the second housing 16 being detached from the first housing 14 and the controller 18 will prevent the supply of power to the heater 22.

[0221] The operation of the latching mechanism 258 and the closing mechanism 259 will now be described with reference to FIGS. 24 to 33.

[0222] FIG. 24 shows the cover element 42 in the closed position. When the cover element 42 is in the closed position, the geared cam follower 264 is biased into a lowered position by the cam follower biasing spring 265 and the release element 268 is maintained in a raised position by the first housing 14, as shown in FIG. 25. In the raised position, an internal rib 290 on the release element 268 is engaged with an external rib 292 on the geared cam follower 264, as shown in FIGS. 32 and 33.

[0223] When the cover element 42 is rotated towards the open position, the rotation of the first gear 262 rotates the geared cam follower 264, which rotates the release element 268. During rotation of the geared cam follower 264, the first cam surface 263 raises the geared cam follower 264 into a raised position against the force of the cam follower biasing spring 265, as shown in FIG. 26. When the cover element 42 reaches the open position, the geared cam follower 264 is received within a detent 271 defined by the first cam surface 263, as shown in FIG. 27. When the geared cam follower 264 is received within the detent 271, the cover element 42 cannot be rotated back towards the closed position.

[0224] When the second housing 16 is moved away from the first housing 14, the release element biasing spring 269 pushed the release element 268 into a lowered position, which disengages the internal rib 290 on the release element 268 from the external rib 292 on the geared cam follower 264. During the motion of the release element 268 into its lowered position, a first projection 273 on the release element 268 engages a second cam surface 275 defined by the chassis 252, which rotates the release element 268 to a position in which a second projection 280 is positioned underneath a third cam surface 282 defined by the chassis 252, as shown in FIGS. 28 and 29.

[0225] When the second housing 16 is moved towards the first housing 14, the first housing 14 pushes the release element 268 upwards against the force of the release element biasing spring 269, as shown in FIG. 30. As the release element 268 moves upwards, the internal rib 290 on the release element 268 engages the external rib 292 on the geared cam follower 264 and disengages the geared cam follower 264 from the detent 271. At the same time, the second projection 280 on the release element 268 engages the third cam surface 282 as shown in FIG. 31, which rotates the release element 268, the geared cam follower 264 and the cover element back to the initial configuration show in FIGS. 24 and 25.

[0226] FIGS. 34 and 35 show a further alternative arrangement of the mechanical linkage 50.

[0227] The further alternative mechanical linkage comprises a chassis 52 attached to the second housing 16 by a screw 54. Mounted onto the chassis 52 is second magnet 56 arranged to interact with the first magnet 28 on the first housing 14. In particular, the first and second magnets 28, 56 are magnetically attracted to each other to facilitate attachment of the second housing 16 to the first housing 14.

[0228] Also mounted on the chassis 52 is a biasing mechanism 58 comprising a washer 60, a first gear 62, a spring holder 64, a torsion spring 66, a spindle 68 and a cap 70.

[0229] The washer 60 is formed from a low friction material to facilitate rotation of the first gear 62 on the chassis 52. The first gear 62 is connected to an end of the shaft portion 48 of the cover element 42 by an interference fit. Therefore, when the cover element 42 is rotated between the closed and open positions, the first gear 62 is also rotated.

[0230] An outer surface of the spring holder 64 forms a second gear 72 that is engaged with the first gear 62. The spring holder 64 is rotatably received within the chassis 52 and engages a cam surface formed on the chassis 52. Therefore, when the spring holder 64 rotates with respect to the cam surface, the spring holder 64 functions as a cam follower and moves up and down along the spindle 68. An indicator element 74 comprising an optically reflective aluminium layer is positioned on a bottom surface of the spring holder 64. When the spring holder 64 moves up and down along the spindle 68, the sensor 26 senses a change in distance between the sensor 26 and the indicator element 74. Based on the sensed distance between the sensor 26 and the indicator element 74, the sensor 26 provides a signal to the controller 18 indicative of whether the cover element 42 is in the closed position or the open position. It will be appreciated that the indicator element 74 may be substituted with either of the alternative arrangements described herein with reference to FIGS. 19 to 22.

[0231] If the signal from the sensor 26 is indicative of the cover element 42 being in the closed position, it is assumed that an aerosol-generating article is not received within the cavity 32 and the controller 18 will not supply power from the power supply 20 to the heater 22 for heating an aerosol-generating article.

[0232] If the signal from the sensor 26 is indicative of the cover element 42 being in the open position, an aerosol-generating article may be received within the cavity 32 and the controller 18 may supply power from the power supply 20 to the heater 22 for heating an aerosol-generating article.

[0233] If the sensor 26 cannot detect the indicator element 74 it is assumed that the second housing 16 has been detached from the first housing 14. In this case, the sensor 26 provides a signal to the controller 18 indicative of the second housing 16 being detached from the first housing 14 and the controller 18 will prevent the supply of power to the heater 22.

[0234] A first end of the torsion spring 66 is engaged with the spring holder 64 and a second end of the torsion spring 66 is engaged with the cap 70. When a user rotates the cover element 42 from the closed position to the open position, the spring holder 64 rotates and loads the tension spring 66. When a user releases the cover element 42, the load on the tension spring 66 exerts a rotational force on the spring holder 64, which biases the cover element 42 from the open position towards the closed position.

[0235] FIG. 36 shows a cross-sectional view of an aerosol-generating article 80 for use with the aerosol-generating device 10. The aerosol-generating article 80 comprises an aerosol-forming substrate 82 in the form of a tobacco plug, a hollow acetate tube 84, a polymeric filter 86, a mouthpiece 88 and an outer wrapper 90. When the aerosol-generating article 80 is received within the cavity 32 of the aerosol-generating device 10, the heater 22 is received within the tobacco plug. During use, the heater 22 heats the tobacco plug to generate an aerosol.