WO2023187029A1

WO2023187029A1 - Aerosol-generating device for use with an aerosol-generating article

Info

Publication number: WO2023187029A1
Application number: PCT/EP2023/058238
Authority: WO
Inventors: Dani Ruscio; Larry Sacha Baudet
Original assignee: Philip Morris Products S.A.
Priority date: 2022-03-31
Filing date: 2023-03-30
Publication date: 2023-10-05
Also published as: EP4498847A1; KR20240170545A; IL315856A; JP2025511041A; US20250204599A1; CN118804696A

Abstract

The present invention relates to an aerosol-generating device for use with an aerosol-generating article. The device comprises a chamber within a device housing for removably receiving at least a portion of the aerosol-generating article. The chamber has a chamber inner surface and a proximal open end for insertion of the article into the chamber. The device further comprises an insert sleeve separate from the device housing, wherein the insert sleeve is fixedly arranged in the device such that at least a portion of the insert sleeve extends along at least a proximal portion of the chamber inner surface. The insert sleeve comprises a sleeve outer surface and a sleeve inner surface. In a contact portion of the insert sleeve the sleeve inner surface is configured to come into circumferentially closed contact with a circumference of the aerosol-generating article when received in the chamber. At least a proximal portion of an airflow path through the device extends along the sleeve outer surface.

Description

Aerosol-generating device for use with an aerosol-generating article

The present invention relates to an aerosol-generating device configured for use with an aerosol-generating article to generate an inhalable aerosol by heating an aerosolforming substrate contained within the article. The invention further relates to an aerosolgenerating system comprising such a device and such an article.

Aerosol-generating devices for use with aerosol-generating articles containing heatable aerosol-forming substrates are generally known from prior art. Such devices may comprise a receiving chamber with an insertion opening for receiving at least a portion of the article. In addition, such devices may comprise a heater, for example a resistive or an inductive heater, for heating the substrate when the article is received within the chamber. The device may be configured such that in use volatile compounds released from the heated substrate are entrained into a user generated airflow through the device to form an aerosol which may be drawn out, for example, through a mouthpiece. The receiving chamber may be configured such that a portion of the airflow path through the device extends from the insertion opening along the inner surface of the chamber towards the other end of the chamber opposite the insertion opening, where the airflow enters the article at the article distal end and further passes towards the article proximal end. In particular, the airflow path may extend along a passage formed between the inner surface of the chamber and the outer surface of the article when received in the chamber.

While such an airflow path has several advantages, for example, preconditioning of the incoming air before mixing with the volatilized substrate, the airflow can suffer pressure drops as it passes along the outer surface of the article. The pressure drops, in turn, can influence the resistance to draw (RTD) of the system.

Therefore, it would be desirable to have an aerosol-generating device and an aerosolgenerating system with the advantages of prior art solutions, whilst mitigating their limitations. In particular, it would be desirable to have an aerosol-generating device and a corresponding system providing an improved airflow management and an improved controllability of the resistance to draw (RTD).

According to the invention there is provided an aerosol-generating device for use with an aerosol-generating article. The device comprises a chamber within a device housing for removably receiving at least a portion of the aerosol-generating article. The chamber has a chamber inner surface and a proximal open end for insertion of the article into the chamber. The device further comprises an insert sleeve separate from the device housing, wherein the insert sleeve is fixedly arranged in the device such that at least a portion of the insert sleeve extends along at least a proximal portion of the chamber inner surface. The insert sleeve comprises a sleeve outer surface and a sleeve inner surface. In a contact portion of the insert sleeve the sleeve inner surface is configured to come into circumferentially closed contact with a circumference of the aerosol-generating article when the article is received in the chamber. At least a proximal portion of an airflow path through the device extends along the sleeve outer surface.

In accordance with the invention, it was found that in aerosol-generating devices of the above described type, the observed pressure drops in the airflow path between the inner surface of the chamber and the outer surface of the aerosol-generating article are at least partially due to the specific properties of the article received in the chamber. In particular, it was found that the porosity of the elements forming the article may cause the observed pressure drops as air flowing along the outer surface of the article during a user's puff may be partially absorbed by the article outer surface. Depending on the specific structure of the article, this effect may especially occur in those portions of the received article which are surrounded by a proximal portion of the chamber inner surface close to the proximal open end of the chamber that is used for inserting the article into the chamber.

In order to reduce such pressure drops the present invention suggests avoiding the airflow through the device to pass along the outer surface of the received article at least in a proximal portion of the chamber. To achieve this, the present invention suggests an insert sleeve which is arranged and configured such that it blocks or at least limits any airflow along the outer surface of the article in the proximal portion of the chamber, and at the same time provides an alternative airflow path through the device in that portion of the chamber. For this, the insert sleeve is arranged such that at least a portion of the insert sleeve extends along at least a proximal portion of the chamber inner surface. Thus, when the article is inserted into the chamber, the article passes through the insert sleeve in the proximal portion of the chamber.

Airflow along the outer surface of the article is blocked or at least limited due to the sleeve inner surface in the contact portion being configured to come into circumferentially closed contact with a circumference of that portion of the article that is arranged within the insert sleeve when the article is received in the chamber.

As used herein, the term "circumferentially closed contact" refers to a sealing contact between the outer surface of the article and the sleeve inner surface in the contact portion along the circumference of the article, that prevents or at least limits airflow between the article outer surface and the sleeve inner surface in the contact portion. For this, the shape of the sleeve inner surface in the contact portion preferably is adapted to the shape of the respective portion of the article which the sleeve inner surface in the contact portion gets into contact with upon insertion of the article into the chamber. In particular, an inner cross-sectional shape of the sleeve inner surface in the contact portion may correspond to an outer cross-sectional shape of the article intended to contact the sleeve inner surface in the contact portion. Whilst the shape of the sleeve inner surface in the contact portion may depend on the aerosol-generating article intended to be received in the sleeve, any suitable shape is conceivable. For example, (at least a section of) the sleeve inner surface in the contact portion may have a cylindrical shape. In addition or alternatively, (at least a section, in particular a section other than a cylindrical section of) the sleeve inner surface in the contact portion may have a conical shape. Preferably, (at least a section of) the sleeve inner surface in the contact portion is a (substantially) smooth surface portion. As used herein, “smooth surface” means free or substantially free from projections and/or unevenness. The inner surface in the contact portion may be a continuous surface. The term “surface contact” may include that two parallel surfaces being arranged in contact with each other have the same bending radius. Likewise, (at least a section of) the inner surface in the contact portion may have a ring shape. For example, a ring-shaped ridge may be provided at the inner surface in the contact portion that come into circumferentially closed contact with a circumference of the aerosol-generating article when the article is received in the chamber. Thus, the ring-shaped ridge can exert an annular retention force to the article when it is received in the chamber. The ring-shaped ridge may have a contact width (in the axial direction of the insert sleeve) in a range between 0.5 millimeter and 2 millimeter. The size of the inner cross-sectional shape of the ring-shaped ridge may vary along the axial direction of the insert sleeve. In particular, the inner cross-sectional shape of the ring-shaped ridge may decrease, in particular smoothly decrease along the axial direction of the insert sleeve in the distal direction. Preferably, the inner cross-sectional shape of the ring-shaped ridge may (smoothly) decrease in the distal direction starting from a maximum inner cross- sectional shape of the contact portion towards a minimum inner cross-sectional shape and then increase again, in particular abruptly such as to form a sharp distal edge of the ringshaped ridge.

According to the invention, the alternative airflow path mentioned above, which extends at least along the proximal portion of the chamber, is realized along the sleeve outer surface. This enables that at least that portion of the outer surface of the article, that is arranged in the proximal portion of the chamber, is by-passed such as not to be exposed to the airflow through the device.

The chamber may have a substantially cylindrical shape. As used herein, the term "substantially cylindrical shape" refers to a shape of the chamber without considering any protrusions, that is, to a shape of an envelope through the radially outermost parts of the inner surface of the chamber.

The chamber has a proximal open end which serves as an insertion opening through which an aerosol-generating article may be inserted into the chamber. As used herein, the direction in which the aerosol-generating article is inserted is denoted as insertion direction. Preferably, the insertion direction corresponds to the extension of the center axis of the chamber. Upon insertion into the chamber, at least a portion of the aerosol-generating article may still extend outwards through the proximal open end. The outwardly extending portion preferably may be provided for interaction with a user, in particular for being taken into a user's mouth. Hence, during use of the device, the proximal open end may be close to the user's mouth. Accordingly, sections close to the proximal open end (insertion opening) or close to a user's mouth in use of the device, respectively, are denoted with the prefix “proximal”. Sections which are arranged further away are denoted with the prefix “distal”. Correspondingly, as used herein “proximal” may imply a direction towards a user of the device whereas “distal” may imply a direction opposite the proximal direction i.e. away from a user of the device. The insertion direction may preferably be a distal direction. The chamber may be arranged or located in a proximal portion of the aerosol-generating device. Likewise, the insertion opening may be arranged or located at a proximal end of the aerosol-generating device.

As used herein “sleeve” may refer to a generally tubular shaped element. In particular, a sleeve may comprise opposite open ends. As used herein “fixedly arranged in the device” means not displaceable, such as spatially fixed in a position in the device or immovably coupled.

The insert sleeve may have a wall thickness in the radial direction (with respect to the center axis of the insert sleeve) of less than 1.0 mm, preferably less than 0.5 mm, more preferably less than 0.2 mm. Thereby, a flow in the airflow path may flow past the sleeve in a substantially axial direction of the chamber without being deflected by the insert sleeve.

A length extension of the sleeve along a center axis of the sleeve may be in a range of 10 to 120 percent of a length extension of the chamber, preferably 20 to 40 percent, more preferably 25 to 30 percent. A length extension of the contact portion may be in a range of 10 to 120 percent of a length extension of the chamber, preferably 20 to 40 percent, more preferably 25 to 30 percent. A length extension of the contact portion may be in a range of 50 to 100 percent of the length extension of the sleeve, preferably 70 to 90 percent, more preferably 75 to 85 percent. In absolute numbers, a length extension of the insert sleeve along a center axis of the sleeve may be in a range between 3.5 mm and 8 mm, in particular between 4 mm and 7 mm, preferably between 4.5 mm and 6.5 millimeter, for example 4.7 mm or 4.75 mm or 6.25 mm. The inner surface in the contact portion may advantageously be configured for retention of the article in the chamber. For example, the inner surface in the contact portion may be configured to cause a frictional force acting on the article that prevents the article from falling out of the chamber in the proximal direction in any spatial orientation of the device. The frictional force may be dependent on the surface roughness of the article outer surface and the force applied by the inner surface in the contact portion to the article outer surface. In particular, it is possible that the aerosol-generating article may be in contact exclusively with the insert sleeve in a proximal portion of the chamber.

In particular, the proximal portion of the airflow path may be formed at least partially between the sleeve outer surface and the chamber inner surface. Thus, the proximal portion of the airflow path is still provided within the chamber. The chamber inner surface may be an innermost surface, facing towards an interior of the chamber.

Due to the insert sleeve being provided as a part of the device, fluid dynamic properties of the sleeve outer surface may be predefined and configured to facilitate desired characteristics of an airflow in the proximal portion of the airflow path.

The insert sleeve may comprise a plurality of airflow channels arranged along a circumference of the sleeve outer surface, wherein the airflow channels form part of the proximal portion of the airflow path. Using such airflow channels, turbulent flow may be reduced - at least to some extent - in the proximal portion of the air path, and thus undesired pressure drops in the device may be further reduced. Alternatively, or in addition, laminar flow in the proximal portion of the air path may be facilitated.

Advantageously, one or more of a width-extension of the airflow channels, a depthextension of the airflow channels or the number airflow channels may be chosen such that upon inserting an aerosol-generating article in the chamber a resistance to draw (RTD) is in a desired range. In non-limiting examples, the number of airflow channels may be in a range of 3 to 15, for example 5 or 12.

The device resistance to draw (RTD) may be in a range of 70 mmWG to 120 mmWG. Preferably, the resistance to draw (RTD) may be between 40 mmWG and 70 mmWG, in particular 45 mmWG and 65 mmWG, for example 55 mmWG.

The plurality of airflow channels may extend substantially along a length extension of the insert sleeve. The length extension of the sleeve may extend along a center axis of the insert sleeve. By this, an airflow along the insert sleeve is guided to flow in a direction substantially along the length extension of the insert sleeve and thus is prevented from flowing in a direction along a circumference of the insert sleeve.

The airflow channels may be formed between adjacent ridges arranged - spaced from each other - along the circumference of the insert sleeve (on the outside of the insert sleeve). The ridges may have a longitudinal extension along the length extension of the insert sleeve. The ridges may be integrally formed with the insert sleeve. Advantageously, the number, the shape and the distance of the plurality of ridges may be chosen such that upon inserting an aerosol-generating article into the chamber, a resistance to draw (RTD) is in the desired range set forth above.

A cross-sectional area of the airflow path through the device may increase downstream of the ridges, due the absence of ridges. It follows that an airflow velocity of an airflow in the airflow path may decrease downstream of the ridges. Thus, the longitudinal extension of the ridges may be adapted such that a change in the airflow velocity, such as a decrease of the airflow velocity, is obtained at a desired location in the chamber. For example, a decrease in velocity of the airflow along at least a portion of a distal portion of the airflow path may facilitate increased pre-heating of the airflow due to the time spent by the airflow in the distal portion for recuperation being prolonged.

A transverse cross-section of the respective ridges may have any suitable shape. Preferably, a cross-section of the respective ridges comprises a substantially rectangular or trapezoid shape, optionally having at least one convex side. However, other shapes are conceivable, such as convex or substantially semi-circular. The ridges may protrude radially outward from a center axis of the insert sleeve. Thereby, an airflow may be guided along the insert sleeve outer surface.

In addition, the ridges may serve to fix the insert sleeve within the device housing and to position the insert sleeve relative to the chamber, in particular coaxial to the chamber. For this, the ridges may be in contact with the chamber inner surface. The contact may be such that the insert sleeve is fixed in the chamber by friction fit. The ridges may respectively comprise an outer contact surface configured to correspond to a radius at bend of the chamber inner surface for contacting the chamber inner surface. In addition, by providing the ridges in contact with the chamber inner surface, adjacent airflow channels may not be in fluid-communication with each other.

The ridges may extend beyond a distal edge of the insert sleeve, in particular such that the insert sleeve comprises a discontinuous distal rim at a distal end of the insert sleeve. The sleeve inner surface may end at the distal edge of the insert sleeve. The sleeve outer surface may end at the distal edge of the insert sleeve. Alternatively, an inner surface (facing towards the center axis of the insert sleeve) of that portion of the ridges, that extends beyond the distal edge of the insert sleeve, may be part of the insert sleeve inner surface.

The ridges may extend beyond a proximal edge of the insert sleeve, in particular such that the insert sleeve comprises a discontinuous proximal rim at a proximal end of the insert sleeve. The sleeve inner surface may end at the proximal edge of the insert sleeve. Likewise, the sleeve outer surface may end at the proximal edge of the insert sleeve. Alternatively, an inner surface (facing towards the center axis of the insert sleeve) of that portion of the ridges, that extends beyond the distal edge of the insert sleeve, may be part of the insert sleeve inner surface. The interstices between proximal end portions of the ridges extending in the proximal direction at a proximal end of the insert sleeve may form axial recesses in fluid communication with the respective airflow channel. The recesses may advantageously form air inlets allowing air to enter the proximal portion of the airflow path, in particular the airflow channels.

Likewise, the airflow channels may be formed by grooves on/in the sleeve outer surface (that is, on the outside of the insert sleeve). The grooves may guide the airflow along the insert sleeve outer surface. The grooves may have a width-extension along a circumference of the sleeve and a depth-extension along a radial direction of the sleeve. A transverse cross-section of the respective grooves may have any suitable shape. Preferably the cross-section of the respective grooves comprises a substantially rectangular or trapezoid shape, optionally having at least one curved side. However, other shapes are conceivable, such as an inwards recessing concave shape or substantially semi-circular.

The chamber may be formed as a sleeve, preferably with a distal closed end, received in a cavity within a proximal portion of the device housing. Likewise, the chamber may be formed as a barrel received in a cavity within a proximal portion of the device housing. The sleeve or barrel may be at least partially inserted into the cavity. The proximal portion of the aerosol-generating device may form part of a device housing. Thus, said cavity may be formed within a housing of the aerosol-generating device. Forming the chamber as a sleeve or barrel may be beneficial with regard to an easy manufacturing and assembling of the device. Alternatively, or in addition, it is facilitated that the chamber may be made of a different material than the proximal portion of the aerosol-generating device, in particular of the device housing. For example, the chamber may comprise or may be at least partially made of a thermal insulation material. The thermal insulation material may be configured to provide thermal insulation to sustain heat within the and to prevent heat conduction between the interior of the chamber and the proximal portion of the aerosolgenerating device, in particular the device housing.

The insert sleeve may cooperate with a proximal portion or a proximal end of the chamber, in particular for locking the sleeve from displacing at least in a distal direction. The insert sleeve may comprise a sleeve distal end that is an unattached end.

The chamber may comprise one or more stops at a distal end of the chamber, configured for preventing the article from displacing at least in a distal direction.

The insert sleeve may comprise an intake portion at a proximal end of the insert sleeve. Advantageously, the intake portion may comprise an enlarged cross-section as compared with other more distal potions of the insert sleeve, for example, that portion of the insert sleeve which extends along the proximal portion of the chamber, in particular the contact portion.

In particular, an inner cross-sectional area of the insert sleeve may increase in the proximal direction along at least a portion of the intake portion. Preferably, the sleeve inner surface may comprise one of a truncated cone shape or a funnel shape in the intake portion. In a non-limiting example, the inner cross-section of the sleeve inner surface may expand to correspond at least to an inner cross-section of the chamber inner surface. Due to this, the sleeve inner surface may advantageously guide an aerosol-generating article during insertion of the article into the device, in particular in a radial direction of the device and towards a position coaxial with the chamber.

Preferably, the intake portion projects in a proximal direction beyond a proximal end of the chamber. This enables that an incoming airflow entering the device may be received and redirected in the intake portion prior to entering the chamber. In particular, an incoming airflow may enter the intake portion or the airflow channels or the intake portion and the airflow channels at a desired angle of incidence relative to a center axis of the insert sleeve. Accordingly, the intake portion may be configured to receive an airflow entering the device. That is, the intake portion may be configured to redirect an airflow as it enters the device.

The intake portion may comprise one or more air inlets for air to enter the proximal portion of the airflow path along the sleeve outer surface, in particular to enter the airflow channels on the sleeve outer surface. The air inlets may be formed and arranged in various configurations in order to realize different airflow management configurations, in particular different ways of supplying air into the proximal portion of the airflow air path.

Depending on the number of airflow channels and air inlets and their size, the total cross-sectional area of the air inlets (all air inlets) may be in a range between 5 and 8 square millimeter, or between 6 and 9 square millimeter, or between 5 and 7 square millimeter between 3 and 5 square millimeter

In general, the air inlets may be arranged at least partially outside the chamber. Likewise, the air inlets may be arranged at least partially inside the chamber. In particular, the air inlets may extend in a distal direction from the intake portion and partially into the chamber. Further details of the air inlets will be discussed further below.

The airflow channels may end in the proximal direction distal of a proximal edge of the insert sleeve. Thus, the airflow channels may be accessible from the outside of the insert sleeve in a radially inward direction with respect to the length extension of the insert sleeve. In particular, the airflow channels may be accessible from the outside of the insert sleeve only in a radially inward direction with respect to the length extension of the insert sleeve. More particularly, the airflow channels may end in the proximal direction distal of a proximal edge of the insert sleeve, thus providing air inlets being accessible from the outside the insert sleeve in a radially inward direction, in particular only in a radially inward direction with respect to the length extension of the insert sleeve.

Having the airflow channels to end in the proximal direction distal of a proximal edge of the insert sleeve may serve to be prevent the airflow channels from becoming blocked by items or debris in the axial direction of the device. This configuration is beneficial in a handheld device, the airflow channels of which may be susceptible to undesired clogging by debris or dirt, for example while being stored or carried in a pocket, bag or like. Such clogging may also unintentionally occur as a user inserts an aerosol-generating article in the device with lacking precision, wherein the article may be brought into contact with airflow channels open in an axial direction. This configuration of the airflow channels may also include that an incoming airflow may first enter the device in a distal direction parallel to the length extension of the insert sleeve and subsequently enter the airflow channels in a radially inward direction with respect of the length extension of the insert sleeve.

Alternatively, the airflow channels may extend in the proximal direction all the way to a proximal edge of the insert sleeve. Thus, the airflow channels may be accessible from the outside of the insert sleeve (at least) in the distal direction, in particular in the distal direction only, or in at least one of the distal direction and a radially inward direction with respect to the length extension of the insert sleeve. More particularly, the airflow channels may extend in the proximal direction all the way to a proximal edge of the insert sleeve, thus providing air inlets being accessible (at least) in the distal direction, in particular in the distal direction only, or in at least one of the distal direction and a radially inward direction with respect to the length extension of the insert sleeve. In any of the latter configurations, an incoming airflow may enter the airflow channels at least in the distal direction, that is, in the direction of the length extension of the airflow channels which may help to reduce the resistance to draw (RTD).

The airflow channels may taper towards the proximal edge of the insert sleeve in at least one of a width extension of the airflow channel and a depth extension of the airflow channel. A transverse cross-section of the airflow channels in such a tapered segment of the airflow channels may comprise a curved shape in at least one of a width extension of the airflow channel and a depth extension of the airflow channel, such as to provide an aerodynamic shape of the airflow channels. Thereby, the resistance to draw (RTD) of the device may be optimized. The insert sleeve may comprise one or more through holes, in particular in the intake portion, that is, through holes through the wall of the insert sleeve, in particular in the intake portion. The one or more through holes provide a fluid communication from the inside of the insert sleeve, in particular from the inside of the intake portion, to the proximal portion of the airflow path on the sleeve outer surface. In particular, the insert sleeve may comprise for each airflow channel a through hole in the intake portion being in fluid communication with the respective airflow channel. Thus, the through holes may allow air to enter the proximal portion of the airflow path, in particular the airflow channels, from the inside of the insert sleeve, in particular from the inside of the intake portion. In other words, the through holes may form air inlets as described above for air to enter the proximal portion of the airflow path, in particular the airflow channels, from the inside of the insert sleeve, in particular from the inside of the intake portion. That is, the one or more air inlets described above may be formed by one or more through holes through the insert sleeve in the intake portion, wherein the through holes allow air to enter the proximal portion of the airflow path, in particular the airflow channels, from the inside of the intake portion. Such air inlets may be denoted as internal air inlets. The through holes may advantageously be sized and configured to optimize an airflow in the intake portion, for example to obtain a desired resistance to draw.

Alternatively, the insert sleeve may comprise one or more axial recesses at the proximal end of the insert sleeve, in particular at a proximal edge of the insert sleeve. In particular, the insert sleeve may comprise for each airflow channel an axial recess being in fluid communication with the respective airflow channel. Like the through holes, the axial recesses may advantageously allow air to enter the proximal portion of the airflow path, in particular the airflow channels, from the inside of the intake portion. In particular, the axial recesses may form air inlets as described above for air to enter the proximal portion of the airflow path, in particular the airflow channels, from the inside of the intake portion. That is, the one or more air inlets described above may be formed by one or more axial recesses at the proximal end of the insert sleeve, in particular at a proximal edge of the insert sleeve, wherein the recesses advantageously allow air to enter the proximal portion of the airflow path, in particular the airflow channels, from the inside of the insert sleeve, in particular from the inside of the intake portion. As already described above, the axial recesses may be formed by respective interstices between proximal end portions of the ridges which extend in the proximal direction at a proximal end of the insert sleeve.

It is also possible that the insert sleeve comprises one or more air inlets, in particular one air inlet for each airflow channel, allowing air to enter the proximal portion of the airflow path, in particular the airflow channels, from the outside of the insert sleeve. Such air inlets may be denoted as external air inlets. In particular, the one or more (external) air inlets may be formed on the outside of the insert sleeve, for example, between a ringshaped support structure (see below), the ridges and the bottom of the airflow channels. Advantageously, such external air inlets ensure that there is no contact between the airflow and the aerosol-generating article in a proximal portion of the chamber.

Furthermore, the insert sleeve may comprise a circumferential collar at the proximal end of the insert sleeve. The collar may have a ring shape or a tubular shape, such as cylindrical. The provision of a collar may be beneficial for fixation of the insert sleeve in the device. In particular, the collar may cooperate with for example the chamber and seal there against.

The circumferential collar may provide a closing-off of the airflow channels in the proximal direction (if present). That is, the airflow channels may end at the collar. Thus, the airflow channels may advantageously be accessible from the outside of the insert sleeve in a radially inward direction with respect to the length extension of the insert sleeve. This may help to prevent that the airflow channels become blocked by items or debris in the axial direction of the device as has been explained herein.

The ridges forming the airflow channels may extend in a proximal direction to merge radially flush with a circumference of the collar. Thus, the airflow channels may advantageously be accessible from the outside of the insert sleeve in a radially inward direction with respect to the length extension of the insert sleeve. Again, this may help to prevent that the airflow channels become blocked by items or debris in the axial direction of the device as has been explained herein.

In particular, the collar may be a turned-over collar comprising a turned-over collar portion surrounding the intake portion spaced from the sleeve outer surface in the intake portion. A turned-over collar portion surrounding the intake portion may be beneficial for fixation of the insert sleeve in the device and sealing the airflow path against the device housing or the chamber.

The ridges may extend into the space between the turned-over collar portion and the intake portion. Advantageously, this allows to keep the airflow channels independent from each other along the turned-over collar and to have each of the airflow channels in separate fluid communication with an individual air inlet in the intake portion.

In order to fixedly arrange the insert sleeve in the device, the insert sleeve may comprise a support structure providing a form-fit with a correspondingly formed counterpart support structure of the chamber. Likewise, the support structure may be configured to provide a press-fit with the counterpart support structure of the chamber. Thereby, the insert sleeve may be form-fitted or press-fitted to the chamber. The support structure may be provided on the ridges which form the airflow channels such that the support structure protrudes beyond the ridges in a direction radially outward from the insert sleeve. As an example, the support structure may be formed by a ring member extending around the circumference of the insert sleeve protruding beyond the ridges in a radially outward direction. Likewise, the support structure may be formed by a ring member extending around the circumference of the turned-over collar portion protruding beyond the turned- over collar portion in a radially outward direction. As another example, the support structure may be formed by a plurality of protrusions, in particular stepped protrusions (stepped in the axial direction of the insert sleeve) on the outside of the of the ridges, preferably a respective (stepped) protrusion on the outside of each one of the ridges. The (stepped) protrusions may be protruding beyond the ridges in a radially outward direction. In particular, the (stepped) protrusions may be arranged in a quasi-ring-like manner around the circumference of the insert sleeve.

In addition to the proximal portion, the airflow path through the device may further comprise a distal portion. The distal portion of the airflow path through the device may be formed between a distal portion of the chamber inner surface and an outer surface of a distal portion of the article located outside the insert sleeve, when the article is received in the chamber. The distal portion of the airflow path is in fluid communication with the proximal portion of the airflow path. This arrangement brings about the advantage that on the one hand a portion of a received aerosol-generating article may be bypassed by means of the proximal airflow path, and is thus prevented from influencing the airflow in the proximal portion of the airflow path, while on the other hand heat that dissipates from the article during operation of the device may be captured by air flowing in a distal portion of the airflow path. The latter may facilitate improved thermal efficiency of the device. In addition, this configuration may help to prevent condensation in the distal portion of the airflow path.

In the configuration described before, the insert sleeve preferably extends only along a proximal portion of the chamber (apart from a possible portion protruding beyond the proximal open end of the chamber in the proximal direction). In other portion(s) of the chamber distal to the proximal portion, the chamber inner surface may directly face the outer surface of an aerosol-generating article received in the chamber. These other portion(s) may comprise a non-contact portion distal to the proximal portion, in which the chamber inner surface may be distanced from the outer surface of an aerosol-generating article when received in the chamber. Advantageously, this prevents the outer surface of the article from being affected by condensate possible forming on that portion of the chamber inner surface. In addition, these other portion(s) may comprise a distal retention portion, distal to the non-contact portion, which is configured to retain a received article in the chamber. The distal retention portion may also be configured to position a received article in a radial direction of the chamber. For both purposes, the chamber inner surface in the distal retention portion may comprise a plurality of protrusions configured to contact at least a portion of the aerosol-generating article received in the chamber. For example, the plurality of protrusions may comprise retention ribs. Preferably, the ribs extend substantially along a direction of the center axis of the chamber. The ribs may have a substantially triangular cross-sectional shape. Alternatively, the ribs may have a substantially rectangular or substantially trapezoid or a substantially semi-oval or a substantially semi-circular cross- sectional shape. The protrusions, in particular the ribs may be chamfered or may comprise at least one chamfer. Preferably, the respective protrusions may be chamfered at a side facing towards the proximal open end of the chamber or may comprise at least one chamfer facing towards the proximal open end of the chamber. Advantageously, this facilitates insertion of the article into the chamber.

In another configuration, the insert sleeve may extend further in the distal direction beyond the proximal portion of the chamber. In this configuration, the insert sleeve may comprise a non-contact portion arranged distal to the contact portion. An inner cross- sectional area of the insert sleeve in the non-contact portion may be larger than an inner cross-sectional area of the insert sleeve in the contact portion. The sleeve inner surface may thus be distanced from a received article at a location distal to the contact portion. Again, this configuration is beneficial in reducing or avoiding undesired condensate effects on the outer surface of an article received in the chamber.

The insert sleeve may further comprise a distal sleeve portion arranged distal to the non-contact portion. The sleeve inner surface in the distal sleeve portion may be configured to come into contact with a circumference of the aerosol-generating article, in particular with a circumference of a distal end portion of the aerosol-generating article, when received in the chamber. The sleeve inner surface in the distal sleeve portion may thus be configured to retain a received article in the chamber. The sleeve inner surface in the distal sleeve portion may also be configured to position a received article in a radial direction of the chamber. For both purposes, the sleeve inner surface in the distal sleeve portion may comprise a plurality of protrusions configured to contact at least a portion of the aerosolgenerating article received in the chamber. For example, the plurality of protrusions may comprise retention ribs. Preferably, the ribs extend substantially along a direction of the center axis of the chamber. The ribs may have a substantially triangular cross-sectional shape. Alternatively, the ribs may have a substantially rectangular or substantially trapezoid or a substantially semi-oval or a substantially semi-circular cross-sectional shape. The protrusions, in particular the ribs may be chamfered or may comprise at least one chamfer. Preferably, the respective protrusions may be chamfered at a side facing towards the proximal open end of the chamber or may comprise at least one chamfer facing towards the proximal open end of the chamber. Advantageously, this facilitates insertion of the article into the chamber.

The insert sleeve may comprise a first sleeve segment comprising the contact portion, a second sleeve segment comprising the non-contact portion and a third sleeve segment comprising the distal sleeve portion. Preferably, the first sleeve segment, the second sleeve segment and the third sleeve segment are parts separate from each other. Providing the sleeve as segments may be beneficial for manufacturing purposes. Furthermore, the sleeve may conveniently be adapted during manufacture, for example to be suitable for use with different aerosol-generating articles.

The aerosol-generating device may comprise a fixation ring at the proximal end of the device configured to fix the insert sleeve and preferably also the chamber, if separate from the device housing, in the device, in particular against the device housing. Preferably, the fixation ring is a screw ring. The screw ring may be configured to screw down the insert sleeve and - if applicable - the chamber against the device housing. The screw ring may be configured to engage with a correspondingly formed threaded portion in the device housing. Alternatively, the fixation ring may be configured to fix the insert sleeve and - if applicable - the chamber by means of a snap-in fixation.

To prevent airflow passing along an outer surface of the chamber, the aerosolgenerating device may comprise a sealing member, such as a gasket or O-ring. The sealing member may be provided at least partially between the insert sleeve and the chamber. The sealing member may provide a seal between the insert sleeve, the chamber and the fixating ring. In particular, the sealing member may abut against the support structure of the insert sleeve.

The device may further comprise a proximal cap, in particular a ring-shaped proximal cap to cover the proximal end face at the proximal end of the device (apart from the open proximal end of the chamber). The proximal cap may comprise an insertion opening for insertion of an aerosol-generating article through the open proximal end of the chamber. Preferably, the proximal cap is configured to be coupled to the primary cap fixation ring. The cross-sectional shape of the insertion opening of the proximal cap may be noncircular. In particular, the proximal cap may comprise protrusions protruding in a radial inward direction of the sleeve into the insertion opening. For example, the protrusions may be configured such as not to cover the air inlets in an axial direction along the center axis of the insert sleeve. Alternatively, the protrusions may be configured to at least partially cover the air inlets in an axial direction along the center axis of the insert sleeve. Thus, the airflow channels may be closed in the axial direction of the insert sleeve, such that the incoming airflow will flow into the airflow channels in a radial direction. Advantageously, the protrusions may be configured to prevent debris from clogging the airflow channels.

A return airflow path may be formed inside the aerosol-generating article when the article is received in the chamber. The return airflow path may be in fluid communication with the airflow path explained herein, in particular with the distal and proximal portion of the airflow path explained herein. As a user draws on the aerosol-generating article, a pressure drop is facilitated in the airflow path, thus causing a user generated airflow in the airflow through the device. In particular, air may enter the proximal portion of the airflow path at the proximal open end of the chamber and further pass in the distal direction along the distal portion of the airflow path towards the distal end of the chamber. There, the airflow may be re-directed and enter the return airflow path in a proximal direction through the aerosol-generating article. Finally, the airflow may exit the return airflow path either through the aerosol-generating article or a mouthpiece connected to the return airflow path.

As used herein, the term "aerosol-generating device" generally refers to an electrically operated device that is capable of interacting with an aerosol-forming substrate provided within an aerosol-generating article, such as to generate an aerosol by heating the substrate. Preferably, the aerosol-generating device is a puffing device for generating an aerosol that is directly inhalable by a user thorough the user's mouth. In particular, the aerosol-generating device is a hand-held aerosol-generating device.

The aerosol-generating device may further comprise a heating device for heating an aerosol-forming substrate within an aerosol-generating article received in the chamber of the device. The heating device may be an inductive heating device. The inductive heating device may comprise an induction source including an inductor which is configured to generate an alternating, in particular high-frequency magnetic field within the chamber. The alternating, in particular high-frequency magnetic field may be in the range between 500 kHz (kilo-Hertz) to 30 MHz (Mega-Hertz), in particular between 5 MHz (Mega-Hertz) to 15 MHz (Mega-Hertz), preferably between 5 MHz (Mega-Hertz) and 10 MHz (Mega-Hertz). Upon inserting an article into the chamber, the alternating magnetic field is used to inductively heat a susceptor which is in thermal contact with or thermal proximity to an aerosol-forming substrate to be heated. The inductor may be arranged such as to surround at least a portion of the chamber or at least a portion of the inner surface of the chamber, respectively. The inductor may be an inductor coil, for example a helical coil, arranged within a side wall of the chamber or on an outer surface of the chamber. Preferably, the inductor may be arranged such as to surround at least the non-contact portion of the chamber or the insert sleeve. More preferably, the inductor may be arranged such as to surround only the least the non-contact portion of the chamber or the non-contact portion the insert sleeve.

Alternatively, the heating device may be a resistive heating device comprising a resistive heating element. The heating resistive element is configured to heat up when an electrical current is passed therethrough due to an immanent ohm resistance or resistive load of the resistive heating element. For example, the resistive heating element may comprise at least one of a resistive heating wire, a resistive heating track, a resistive heating grid or a resistive heating mesh. In use of the device, the resistive heating element is in thermal contact with or thermal proximity to an aerosol-forming substrate to be heated.

The aerosol-generating device may further comprise a controller configured to control operation of the device. In particular, the controller may be configured to control the heating device, preferably in a closed-loop configuration, for controlling heating of the aerosolforming substrate to a pre-determined operating temperature. The operating temperature used for heating the aerosol-forming substrate may be at least 180 degree Celsius, in particular at least 300 degree Celsius, preferably at least 350 degree Celsius, more preferably at least 370 degree Celsius, most preferably at least 400 degree Celsius.

The aerosol-generating device may comprise a power supply, in particular a DC power supply configured to provide a DC supply voltage and a DC supply current to the heating device. Preferably, the power supply is a battery, in particular a rechargeable battery, such as a lithium iron phosphate battery.

According to the invention there is provided an aerosol-generating system comprising an aerosol-generating device according to the present invention and as described herein, as well as an aerosol-generating article comprising an aerosol-forming substrate. At least a portion of the aerosol-generating article may be removably received or removably receivable in the chamber of the aerosol-generating device.

As used herein, the term "aerosol-generating article" refers to an article comprising at least one aerosol-forming substrate that, when heated, releases volatile compounds that can form an aerosol. Accordingly, the aerosol-generating article may be denoted as a heated aerosol-generating article or an aerosol-generating article for heating. That is, the aerosol-generating article preferably comprises at least one aerosol-forming substrate that is intended to be heated rather than combusted in order to release volatile compounds that can form an aerosol. The aerosol-generating article may be a consumable, in particular a consumable to be discarded after a single use.

As used herein, the term "aerosol-forming substrate" relates to a substrate capable of releasing volatile compounds that can form an aerosol when heated. The aerosol-forming substrate may be a solid aerosol-forming substrate or a gel-like aerosol-forming substrate or a liquid aerosol-forming substrate or a combination thereof. The aerosol-forming substrate may comprise a tobacco-containing material containing volatile tobacco flavor compounds, which are released from the substrate upon heating. Alternatively or additionally, the aerosol-forming substrate may comprise a non-tobacco material. The aerosol- forming substrate may further comprise an aerosol former. Examples of suitable aerosol formers are glycerin and propylene glycol. The aerosol-forming substrate may also comprise other additives and ingredients, such as nicotine or flavoring substances. In particular, liquid aerosol-forming substrate may include water, solvents, ethanol, plant extracts and natural or artificial flavors. The aerosol-forming substrate may also be a pastelike material, a sachet of porous material comprising aerosol-forming substrate, or, for example, loose tobacco mixed with a gelling agent or sticky agent, which could include a common aerosol former such as glycerin, and then is compressed or molded into a plug.

The aerosol-generating article may be a tobacco article. In particular, the article may be a rod-shaped article, preferably a cylindrical rod-shaped article, which may resemble conventional cigarettes. The aerosol-generating article may have a circular or elliptical or oval or square or rectangular or triangular or a polygonal cross-section.

As an example, the aerosol-generating article may be a rod-shaped article. In particular a cylindrical article comprising one or more of the following elements: a distal front plug element, a substrate element, a first tube element, a second tube element, and a filter element.

The substrate element preferably comprises the at least one aerosol-forming substrate to be heated and the susceptor arrangement in thermal contact with or thermal proximity to the aerosol-forming substrate. The substrate element may have a length of 10 millimeter to 14 millimeter, for example, 12 millimeter. In case the aerosol-generating system is based on induction heating, the substrate element may further comprise a susceptor which is in thermal contact with or thermal proximity to the aerosol-forming substrate. As used herein, the term "susceptor" refers to an element comprising a material that is capable of being inductively heated within an alternating electromagnetic field. This may be the result of at least one of hysteresis losses or eddy currents induced in the susceptor, depending on the electrical and magnetic properties of the susceptor material.

The first tube element is more distal than the second tube element. Preferably, the first tube element is proximal of the substrate element, whereas the second tube element is proximal of the first tube element and distal of the filter element, that is, between the first tube element and the filter element. At least one of the first tube element and the second tube element may comprise a central air passage. A cross-section of the central air passage of the second tube element may be larger than a cross-section of the central air passage of the first tube element. Preferably, at least one of the first tube element and the second tube element may comprise a hollow cellulose acetate tube. At least one of the first tube element and the second tube element may have a length of 6 millimeter to 10 millimeter, for example, 8 millimeters.

The filter element preferably serves as a mouthpiece, or as part of a mouthpiece together with the second tube element. As used herein, the term "mouthpiece" refers to a portion of the article through which the aerosol exits the aerosol-generating article. The filter element may have a length of 10 millimeter to 14 millimeter, for example, 12 millimeter.

The distal front plug element may be used to cover and protect the distal front end of the substrate element. The distal front plug element may have a length of 3 millimeter to 6 millimeter, for example, 5 millimeter. The distal front plug element may be made of the same material as the filter element

All of the aforementioned elements may be sequentially arranged along a length axis of the article in the above described order, wherein the distal front plug element preferably is arranged at a distal end of the article and the filter element preferably is arranged at a proximal end of the article. Each of the aforementioned elements may be substantially cylindrical. In particular, all elements may have the same outer cross-sectional shape and/or dimensions.

In addition, the elements may be circumscribed by one or more outer wrappers such as to keep the elements together and to maintain the desired cross-sectional shape of the rod-shaped article. Preferably, the wrapper is made of paper. The wrapper may further comprise adhesive that adheres the overlapped free ends of the wrapper to each other. For example, the distal front plug element, the substrate element and the first tube element may be circumscribed by a first wrapper, and the second tube element and the filter element may be circumscribed by a second wrapper. The second wrapper may also circumscribe at least a portion of the first tube element (after being wrapped by the first wrapper) to connect the distal front plug element, the substrate element and the first tube element being circumscribed by a first wrapper to the second tube element and the filter element. The second wrapper may comprise perforations around its circumference.

Where the aerosol-generating device is intended for use with an aerosol-generating article according to the specific example described before (two support elements), the device and the article are preferably configured such that the first tube element is in contact with the sleeve inner surface of the contact portion of the insert sleeve, whereas the distal front plug element preferably is in contact with the chamber inner surface in the distal retention portion of the chamber or with the sleeve inner surface in the distal sleeve portion of the insert sleeve, respectively. The substrate element is surrounded by the non-contact portion of the chamber or the insert sleeve, respectively, yet without being in contact with the chamber inner surface or the insert sleeve. Preferably, the first tube element may have a length in a direction along a length axis of the article which corresponds to a length of the insert sleeve, in particular a length of the contact portion along the center axis of the chamber. Likewise, the distal front plug element may have a length in a direction along a length axis of the article which corresponds to a length of the retention portion of the chamber or the distal sleeve portion along the center axis of the chamber. Accordingly, the substrate element may have a length in a direction along a length axis of the article which corresponds to a length of the non-contact portion of the chamber or the insert sleeve along the center axis of the chamber. Alternatively, at least one of the insert sleeve, in particular the contact portion, and the retention portion of the chamber or the distal sleeve portion may have a length extension in a respective direction towards the substrate element which is larger than a respective length extension of the first tube element or the distal front plug element such as to get at least partially into touch with the substrate element.

Any of the aforementioned configurations is advantageous for several reasons: First, the airflow in a proximal portion of the airflow path is optimized in respect of resistance to draw. Furthermore, the airflow in the airflow path is pre-heated curtesy of the close proximity of the airflow path and the aerosol-generating article. Due to the contact portion of the sleeve, the article is in addition securely retained within the chamber without the risk to be displaced or to fall out of the device.

Further features and advantages of the aerosol-generating system and the aerosol-generating article according to the present invention have already been described above with regard to aerosol-generating device and thus equally apply.

The invention is defined in the claims. However, below there is provided a non- exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

Example Ex1 : An aerosol-generating device for use with an aerosol-generating article, the device comprising a chamber within a device housing for removably receiving at least a portion of the aerosol-generating article, the chamber having a chamber inner surface and a proximal open end for insertion of the article into the chamber, the device further comprising an insert sleeve separate from the device housing, being fixedly arranged in the device such that at least a portion of the insert sleeve extends along at least a proximal portion of the chamber inner surface, wherein the insert sleeve comprises a sleeve outer surface and a sleeve inner surface, wherein in a contact portion of the insert sleeve the sleeve inner surface is configured to come into circumferentially closed contact with a circumference of the aerosol-generating article when received in the chamber, and wherein at least a proximal portion of an airflow path through the device extends along the sleeve outer surface.

Example Ex2: The aerosol-generating device according to example Ex1 , wherein the proximal portion of the airflow path is formed at least partially between the sleeve outer surface and the chamber inner surface.

Example Ex3: The aerosol-generating device according to any one of the preceding examples, wherein the insert sleeve comprises a plurality of airflow channels arranged along a circumference of the sleeve outer surface, the airflow channels forming part of the proximal portion of the airflow path.

Example Ex4: The aerosol-generating device according to example Ex3, wherein the plurality of airflow channels extend substantially along a length extension of the insert sleeve.

Example Ex5: The aerosol-generating device according to any one of the preceding examples, wherein the airflow channels are formed between adjacent ridges arranged spaced from each other along the insert circumference of the sleeve.

Example Ex6: The aerosol-generating device according to example Ex5, wherein the ridges protrude radially outward from a center axis of the insert sleeve.

Example Ex7: The aerosol-generating device according to any one of example Ex5 or example Ex6, wherein the ridges are in contact with the chamber inner surface.

Example Ex8: The aerosol-generating device according to any one of examples Ex5 to Ex7, wherein the ridges extend beyond a distal edge of the insert sleeve.

Example Ex9: The aerosol-generating device according to any one of examples Ex5 to Ex9, wherein the ridges extend beyond a proximal edge of the insert sleeve.

Example Ex10: The aerosol-generating device according to any one of example Ex3 or example Ex4, wherein the airflow channels are formed by grooves on the sleeve outer surface.

Example Ex11 : The aerosol-generating device according to any one of the preceding examples, wherein the chamber is formed as a sleeve, preferably with a distal closed end, or a barrel received in a cavity within a proximal portion of the device housing.

Example Ex12: The aerosol-generating device according to any one of the preceding examples, wherein the insert sleeve comprises an intake portion at a proximal end of the insert sleeve, preferably the intake portion projects in a proximal direction beyond a proximal end of the chamber.

Example Ex13: The aerosol-generating device according to example Ex12, wherein an inner cross-sectional area of the insert sleeve increases in the proximal direction along at least a portion of the intake portion, preferably the sleeve inner surface comprises one of a truncated cone shape or a funnel shape in the intake portion.

Example Ex14: The aerosol-generating device according to any one of example Ex12 or example Ex13, wherein the intake portion comprises one or more air inlets for air to enter the proximal portion of the airflow path along the sleeve outer surface, in particular to enter the airflow channels on the sleeve outer surface.

Example Ex15: The aerosol-generating device according to any one of examples Ex3 to Ex14, wherein the airflow channels end in the proximal direction distal of a proximal edge of the insert sleeve, thus being accessible, in particular from the outside of the insert sleeve, in a radially inward direction, in particular only in a radially inward direction (with respect to the length extension of the insert sleeve).

Example Ex16: The aerosol-generating device according to any one of examples Ex3 to Ex15, wherein the airflow channels end in the proximal direction distal of a proximal edge of the insert sleeve, thus providing air inlets being accessible, in particular from the outside of the insert sleeve, in a radially inward direction, in particular only in a radially inward direction (with respect to the length extension of the insert sleeve).

Example Ex17: The aerosol-generating device according to any one of examples Ex3 to Ex14, wherein the airflow channels extend in the proximal direction (all the way) to a proximal edge of the insert sleeve, thus being accessible (from the outside of the insert sleeve) in at least one of the distal direction and a radially inward direction (with respect to the length extension of the insert sleeve).

Example Ex18: The aerosol-generating device according to any one of examples Ex3 to Ex14, wherein the airflow channels extend in the proximal direction (all the way) to a proximal edge of the insert sleeve, thus providing air inlets being accessible in at least one of the distal direction and a radially inward direction (with respect to the length extension of the insert sleeve.

Example Ex19: The aerosol-generating device according to any of example Ex17 or example Ex18, wherein the airflow channels taper towards the proximal edge of the insert sleeve in at least one of a width extension of the airflow channel and a depth extension of the airflow channel.

Example Ex20: The aerosol-generating device according to any one of examples Ex3 to Ex14, wherein the insert sleeve comprises one or more through holes in the intake portion, (in particular the insert sleeve comprises for each airflow channel a through hole in the intake portion being in fluid communication with the respective airflow channel), the through holes (forming air inlets) allowing air to enter the proximal portion of the airflow path, in particular the airflow channels, from the inside of the insert sleeve, in particular from the inside of the intake portion.

Example Ex21 : The aerosol-generating device according to any one of examples Ex3 to Ex14, wherein one or more air inlets are formed by one or more through holes through the insert sleeve, in particular in the intake portion, the through holes allowing air to enter the proximal portion of the airflow path, in particular the airflow channels, from the inside of the insert sleeve, in particular from the inside of the intake portion.

Example Ex22: The aerosol-generating device according to any one of examples Ex3 to Ex14, wherein the insert sleeve comprises one or more axial recesses at a proximal end of the insert sleeve, in particular in or at a proximal edge of the insert sleeve, the recesses (forming air inlets) allowing air to enter the proximal portion of the airflow path, in particular the airflow channels, from the inside of the insert sleeve, in particular from the inside of the intake portion.

Example Ex23: The aerosol-generating device according to any one of examples Ex3 to Ex14, wherein the insert sleeve comprises for each airflow channel an axial recesses at a proximal end of the insert sleeve, in particular in or at a proximal edge of the insert sleeve, being in fluid communication with the respective airflow channel, the recesses (forming air inlets) allowing air to enter the proximal portion of the airflow path, in particular the airflow channels, from the inside of the insert sleeve, in particular from the inside of the intake portion.

Example Ex24: The aerosol-generating device according to any one of examples Ex3 to Ex14, wherein the one or more air inlets are formed by one or more axial recesses at a proximal end of the insert sleeve, in particular in or at a proximal edge of the intake portion, the recesses allowing air to enter the proximal portion of the airflow path, in particular the airflow channels, from the inside of insert sleeve, in particular from the inside of the intake portion.

Example Ex25: The aerosol-generating device according to any one of examples Ex22 to Ex24, wherein the recesses are formed by respective interstices between proximal end portions of the ridges extending in the proximal direction at a proximal end of the insert sleeve.

Example Ex26: The aerosol-generating device according to any one of examples Ex1 to Ex21 , wherein the insert sleeve comprises a circumferential collar at the proximal end of the insert sleeve.

Example Ex27: The aerosol-generating device according to example Ex26, wherein the collar provides a circumferential closing-off of the airflow channels (if present) in the proximal direction.

Example Ex28: The aerosol-generating device according to any of example Ex 26 or example Ex27, wherein the ridges merge radially flush with a circumference of the collar.

Example Ex29: The aerosol-generating device according to any of Ex 26 or example Ex27, wherein the collar is a turned-over collar comprising a turned-over collar portion surrounding the intake portion spaced from the sleeve outer surface in the intake portion.

Example Ex30: The aerosol-generating device according to example Ex 29 wherein ridges extend into the space between the turned-over collar portion and the intake portion.

Example Ex31 : The aerosol-generating device according to any one of the preceding examples, wherein the insert sleeve comprises a support structure providing a form-fit with a correspondingly formed counterpart support-support structure of the chamber.

Example Ex32: The aerosol-generating device according to any one of the preceding examples, wherein a distal portion of the airflow path is formed between a distal portion of the chamber inner surface and an outer surface of a distal portion of the article located outside the insert sleeve, when the article is received in the chamber, wherein the distal portion of the airflow path is in fluid communication with the proximal portion of the airflow path.

Example Ex33: The aerosol-generating device according to the examples Ex1 to Ex32 wherein the insert sleeve comprises a non-contact portion arranged distal to the contact portion, wherein an inner cross-sectional area of the insert sleeve in the non-contact portion is larger than an inner cross-sectional area of the insert sleeve in the contact portion.

Example Ex34: The aerosol-generating device according to the preceding example Ex33, wherein the insert sleeve comprises a distal sleeve portion arranged distal to the noncontact portion, wherein the sleeve inner surface in the distal sleeve portion is configured to come into contact with a circumference of the aerosol-generating article, in particular with a circumference of a distal end portion of the aerosol-generating article, when received in the chamber,

Example Ex35: The aerosol-generating device according to example Ex34, wherein the insert sleeve comprises a first sleeve segment comprising the contact portion, a second sleeve segment comprising the non-contact portion and a third sleeve segment comprising the distal sleeve portion, wherein the first sleeve segment, the second sleeve segment and the third sleeve segment are parts separate from each other.

Example Ex36: An aerosol-generating system comprising an aerosol-generating device according to any one of the preceding examples and an aerosol-generating article comprising an aerosol-forming substrate, wherein at least a portion of the aerosolgenerating article is removably received or removably receivable in the chamber of the aerosol-generating device.

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

Fig. 1a shows a chamber with in insert sleeve for use in an aerosolgenerating device according to a first embodiment of the present invention;

Fig. 1b shows a cross-sectional view of the embodiment of Fig.1a;

Fig. 1c shows the embodiment of Fig.1b when an aerosol-generating article is at least partially received in the chamber;

Figs. 2a-2b show isometric views of the insert sleeve of the embodiment shown in Fig. 1a-1c;

Figs. 2c-2d show isometric views of an alternative embodiment of the insert sleeve according to Fig. 1a-1c;

Fig. 3a shows assembling of the insert sleeve to the chamber according to the embodiment shown in Fig. 1a-1c;

Fig. 3b shows an exploded view of certain details of an aerosol-generating device according to the present invention;

Fig. 4a shows a cross-sectional view of the device according to Fig. 3b;

Fig. 4b shows a front view of a proximal end of the device according to Fig. 4a along the center axis of the sleeve;

Fig. 4c shows the device according to Fig. 4a when an aerosol-generating article is at least partially received in the chamber;

Fig. 5a shows an insert sleeve according to a second embodiment;

Fig. 5b shows a cross-sectional view of the sleeve according to Fig. 5a inserted into a chamber;

Fig. 5c shows an isometric view of the embodiment according to Fig. 5b;

Fig. 5d shows the embodiment of Fig. 5b when an aerosol-generating article is at least partially received in the chamber;

Fig. 6a shows an insert sleeve according to a third embodiment;

Fig. 6b shows the embodiment of Fig. 6a when an aerosol-generating article is at least partially received in the chamber,

Fig. 6c a front view of a proximal end of the device of Fig. 6b;

Fig. 6d shows a perspective view of the embodiment of Fig. 6b;

Figs. 7a-7b show isometric views of an insert sleeve according to a third embodiment;

Fig.7c shows a cross-sectional view a chamber comprising the sleeve according to Figs. 7a-7b along the center axis of the sleeve;

Fig.7d shows a front view of a proximal end of a chamber according to the embodiment of Fig.7c;

Figs.7e-7f show further details of the embodiment of Fig. 7c-7d;

Fig.8a shows an exploded view of an insert sleeve and a chamber according to a fourth embodiment;

Fig.8b shows an aerosol-generating device comprising the insert sleeve and the chamber of Fig.8a;

Figs. 9a-9b show isometric views of an insert sleeve according to a fifth embodiment;

Figs. 10a-10b show isometric views of an insert sleeve according to a sixth embodiment; and

Figs. 11a-11 b show isometric views of an insert sleeve according to a seventh embodiment.

Figs. 1a-1c show a first embodiment of a chamber 110 with an insert sleeve 130 for use in an aerosol-generating device according to the present invention. Further details of the aerosol-generating device, in particular of the chamber 110 and the insert sleeve 130 are shown in Figs. 2a-2b, Figs. 3a-3b and Figs. 4a-4c and will be described further below. While Fig. 1a is a front view as seen along a chamber center axis 117, Fig. 1b is a cross- sectional side view of the configuration. As can be seen in particular from Fig. 1b, the insert sleeve 130 is arranged at least partially inserted in the chamber 110. Fig. 1c additionally shows an aerosol-generating article 170, a portion of which is received in the insert sleeve 130 and the chamber 110.

The chamber 110 has a chamber inner surface 113 and a chamber outer surface 114. The proximal open end 115 of the chamber enables insertion of the article 170 into the chamber 110. When the article is received in the chamber 110, a first airflow path 180 - as indicated in Fig. 4c - is formed between the chamber inner surface 113 and the aerosolgenerating article 170. As can be further seen in Fig. 4c, the first airflow path 180 is in fluid communication with a second return airflow path 188 inside the article 170. As used herein, the term “the airflow path” primarily refers to the first airflow path 180. The first 180 and second airflow path 188 are fluidly connected via the free space between one or more stops 118 which are arranged at a distal end 123 of the chamber 110. The stops 118 provide an abutment for the aerosol-generating article preventing it from being inserted to the very distal end of the chamber, thus enabling the airflow to change its course from the distal direction in the first airflow path into the proximal direction in the second airflow path 188.

As can be especially seen in Fig. 4a, the insert sleeve 130 is an element separate from the device housing 103 and separate from the chamber 110. That is, the sleeve 130, the device housing 103 and the chamber 130 are separate elements. Upon assembling, the sleeve 130 is fixedly arranged in the device 101 such that at least a portion of the insert sleeve 130 extends along at least a proximal portion 111 of the chamber inner surface 113 (see Fig. 1c).

The insert sleeve 130 comprises a sleeve outer surface 136 and a sleeve inner surface 134 (see Fig. 2a and 2b). The insert sleeve 130 is arranged coaxial with the chamber 110. Thus, a sleeve length extension 131 of the insert sleeve 130 is parallel the chamber center axis 117. In a contact portion 135 of the insert sleeve 130, the sleeve inner surface 134 is arranged in circumferentially closed contact with a circumference of the aerosol-generating article 170 when the article 170 is received in the chamber (see Fig. 1c, Fig. 4a, and Fig. 4c). For this, the article 170 has an outer cross-sectional shape corresponding at least to an inner cross-sectional shape of the contact portion 135. In particular, a diameter of the outer cross-sectional shape of the article 170 corresponds at least to a diameter of the inner cross-sectional shape of the contact portion 135. Thus, the article 170 is securely retained in the chamber 110 by the contact portion 135. At the same time, the circumferentially closed contact provides a sealing contact between the outer surface of the article 170 and the sleeve inner surface 134 in the contact portion 135 along the article circumference. As a result, the sealing contact that prevents or at least limits airflow through the proximal portion of the chamber 110 between the outer surface of the article 170 and the sleeve inner surface 134 in the contact portion 135. Instead, according to the present invention, the airflow path 180 through the proximal portion of the chamber 110, that is, a proximal portion 181 of the airflow path 180 extends along the sleeve outer surface 136. More particularly, the proximal portion 181 of the airflow path 180 is formed at least partially between the sleeve outer surface 136 and the chamber inner surface 113 (see Fig. 4c).

As shown for example in Figs. 2a-2b, the insert sleeve 130 comprises a plurality of airflow channels 132 arranged along a circumference of the sleeve outer surface 136. The airflow channels 132 forming part of the proximal portion 181 of the airflow path 180. The plurality of airflow channels 132 extend substantially along a length extension 131 of the insert sleeve 130 from a proximal end 143 to a distal end 144 of the insert sleeve 130, in particular 130 from a proximal edge 142 to a distal edge 141 of the insert sleeve 130. The chamber 110 has a length extension 119 along a center axis 117 of the chamber 110. , which is parallel with the chamber center axis 117.

In the present embodiment, the airflow channels 132 are formed between adjacent ridges 137 which are arranged spaced from each other along the circumference of the insert sleeve 130 (on the outside of the insert sleeve 130). The ridges 137 protrude radially outward from a center axis 140 of the insert sleeve 130 to be in contact with the chamber inner surface 113 such that the insert sleeve 130 is radially supported in the chamber 110 via the ridges 137. In addition, the insert sleeve 130 comprises a support structure 155 providing a form-fit with a correspondingly formed counterpart support structure 120 of the chamber 110. In the present embodiment (see Fig. 1 b), the support structure 155 is formed by a ring member protruding beyond the ridges 137 in a radially outward direction.

As shown in Fig.1b and also in Fig.4c, Fig.5d, Fig.6b and Fig.8b, the aerosolgenerating article 170 is a rod-shaped article 170 having a substantially cylindrical shape. The article 170 according to the present embodiment comprises the following cylindrical elements which are sequentially arranged along a length axis of the article 170: a distal front plug element 172, a substrate element 173, a first tube element 174, a second tube element 175, and a filter element 176. Details of these elements have already been described further above. The distal front plug element 172, the substrate element 173 and the first tube element 174 are circumscribed by a first wrapper, and the second tube element 175 and the filter element 176 are circumscribed by a second wrapper. The second wrapper also circumscribes at least a portion of the first tube element 174 (after being wrapped by the first wrapper) to connect the distal front plug element 172, the substrate element 173 and the first tube element 173 (being circumscribed by a first wrapper) to the second tube element 175 and the filter element 176. As shown in Fig.4c, the article 170 of the present embodiment is an inductively heatable article comprising a susceptor element 127 configured to heat the aerosol-forming substrate within the substrate element 173 by means of induction heating.

When the article 170 is received in the chamber 110, the first tube element 174 is at least partially surrounded by the sleeve inner surface 134 of the contact portion 135, with the article outer surface 171 parallel to the contact portion 135. More particularly, (at least a section of) the inner surface in the contact portion 135 is in circumferential closing surface contact with wrapper(s) around the first tube element 174 such that airflow along that portion of the article 170 is prevented. Thus, the insert sleeve 130 with its contact portion 135 prevents air from being absorbed by that portion of the article 170, when a user takes a puff.

In a distal retention portion 122 as shown, for example, in Fig. 1 b and Fig.1c, the chamber 110 comprises retention ribs 116 extending in a radial direction towards the center axis 117 of the chamber 110. The retention ribs 116 are configured to contact a distal portion of the received article 170 for retaining the article 170 in the chamber 110, preferably during any spatial orientation of the chamber 110. The retention ribs 116 extend along the center axis 117 of the chamber 170 and project radially inward beyond a distal portion 114 of the sleeve inner surface 113. Preferably, the retention ribs 116 are integrally formed with the chamber 110. Between the distal retention portion 122 and the proximal portion, the chamber 110 comprises a non-contact portion having a larger inner cross-sectional shape than the distal retention portion 122 and the insert sleeve 130. Thus, the chamber inner surface in the noncontact portion is distanced from the outer surface of an aerosol-generating article 170 when received in the chamber 110. Advantageously, this prevents the outer surface of the part of the article 170 from being affected by condensate possible forming on the chamber inner surface.

Further with reference to Figs. 1a-1d and Figs. 2a-2b, the insert sleeve 130 comprises an intake portion 133 at a proximal end 143 (in particular proximal edge 142) of the insert sleeve 130. Preferably, the intake portion 133 projects in a proximal direction beyond a proximal end 115 of the chamber 110. An inner cross-sectional area of the insert sleeve 130 increases in the proximal direction along at least a portion of the intake portion 133. The sleeve inner surface 134 comprises one of a truncated cone shape or a funnel shape in the intake portion 133. Advantageously, the truncated cone shape provides a guidance for the aerosol-generating article 170 during insertion into the device,

As can be particularly seen in Fig. 2b, the insert sleeve 130 comprises a plurality of through holes 149 in the intake portion 133, one for each airflow channel 132, such as to provide an individual fluid communication for each airflow channel 132. The through holes 149 form air inlets 145 allowing air to enter the proximal portion 181 of the airflow path 180, formed by the airflow channels 132, from the inside of the intake portion 133. Thus, the airflow channels 132 are accessible for an incoming airflow to enter at least in a direction along the sleeve center axis 140.

The insert sleeve 130 further comprises a circumferential collar 139 at the proximal end 143 of the insert sleeve 130. In the present embodiment, the collar 139 is a turned-over collar comprising a turned-over collar portion surrounding the intake portion 133 spaced from the sleeve outer surface 136 in the intake portion 133 (see also Figs. 1b -1c). The ridges 137 forming the airflow channels 132 extend into the space between the turned-over collar portion of the turned-over collar and the intake portion 133.

While Figs. 1a-1d and Figs. 2a-2b show an insert sleeve 130 having twelve ridges 137 and, accordingly, twelve airflow channels and twelve through holes 149/air inlets 145, Figs. 2c-2d show an alternative embodiment of the insert sleeve having five ridges 137 and, accordingly five airflow channels and five through holes 149 or air inlets 145, respectively.

As has been explained further above and as shown in Figs. 1a-1d, Figs. 3a-3b and Figs. 4a-4c, the chamber 110 according to the present embodiment is formed as a sleeve with a distal closed end or, likewise, as a barrel received in a cavity 105 within the proximal portion 104 of the device housing 103.

Figs. 3a-3b show an exploded view of the proximal potion 104 of the aerosolgenerating device which illustrate the assembly of the chamber 110 and the insert sleeve 130 into the cavity 105 within the proximal portion 104 of the device housing 103, thus resulting in the aerosol-generating device shown in Figs. 4a-4c. Upon inserting the chamber 110 into the cavity 105, the sleeve 130 is inserted into the chamber 110. Subsequently, a sealing member 108 is provided at least partially between the chamber 110 and the insert sleeve 130 in order to prevent airflow passing along the outer surface of the chamber 110. The chamber 110, the sleeve 130 and the sealing member 108 are fixedly secured to the device housing 103 by means of the fixation ring 106. In the present embodiment, the fixation ring 106 is a screw ring configured to engage with a correspondingly formed threaded portion in the device housing 103. Finally, a ring-shaped proximal cap 107 is attached to the proximal end face at the proximal end of the device 101 to cover the proximal end face. The proximal cap 107comprises a respective insertion opening 124 for insertion of an aerosol-generating article 170 through the open proximal end of the chamber 110. Preferably, the proximal cap 107 is configured to be coupled to the fixation ring 106. As can be seen especially from Figs. 3b and 4b, the cross-sectional shape of the insertion opening 124 of the proximal cap 107 is non-circular. In particular, the proximal cap 107 comprises protrusions 126 protruding in a radial direction of the sleeve 130 such as to at least partially cover the inlets 145 along the distal direction, as shown for example in Fig. 4b.

Figs. 5a-5d show details of an aerosol-generating device according to the present invention which comprises an insert sleeve 530 according to a second embodiment. In general, the embodiment according to Figs. 5a-5d is very similar to the embodiment shown in Fig. 1a - Fig. 4c. Therefore, identical or similar features are denoted with the same reference signs, yet incremented by 400. In contrast to the embodiment of the insert sleeve 130 shown in Fig. 1a - Fig. 4c, the insert sleeve 530 according to the second embodiment shown in Figs. 5a -5d, does not comprises any collar at its proximal end, in particular any turned-over circumferential collar. Instead, the airflow channels 532 extend in the proximal direction all the way to a proximal edge 542 of the insert sleeve 530, thus being accessible from the outside of the insert sleeve 530 in at least one of the distal direction and a radially inward direction with respect to the length extension of the insert sleeve 530. As can be seen in particular in Fig. 5a, the airflow channels 532 taper towards the proximal edge 542 of the insert sleeve in at least one of a width extension of the airflow channel 532 and a depth extension of the airflow channel 532. This configuration results in a widening of the airflow channels 532 in the intake portion 533 in a distal direction that may be beneficial for aerodynamics of the intake portion 533. The airflow channels 532 also taper in an opposite distal direction. In particular, the airflow channels 532 taper downstream of the support structure 555 of the insert sleeve 530. As can be also seen in Fig.5a, the ridges 537 extend beyond a distal edge 541 of the sleeve 530.

Figs. 6a-6d show details of another aerosol-generating device according to the present invention which comprises an insert sleeve 630 according to a third embodiment. In general, the embodiment according to Figs. 6a-6d is very similar to the embodiment shown in Figs.5a-5d. Therefore, identical or similar features are denoted with the same reference signs, yet incremented by 100. Like in Figs. 5a-5d, the airflow channels 632 extend in the proximal direction all the way to a proximal edge 642 of the insert sleeve 630, thus being also accessible from the outside of the insert sleeve 630 in at least one of the distal direction and a radially inward direction with respect to the length extension of the insert sleeve 630. In contrast to the embodiment shown in Figs. 5a-5d, the insert sleeve 630 comprises ridges 637 extending beyond the proximal edge 642 of the insert sleeve 630. The interstices between the protruding proximal ends of the ridges 637 form axial recesses 646 at the proximal end of the insert sleeve. Each axial recesses 646 is in fluid communication with a respective airflow channel 632, thus forming respective air inlets 645 allowing air to enter the proximal portion 681 of the airflow path 680 from the inside of the intake portion 633. As is derivable from Fig. 6a, the proximal edge 642 and the proximal end portions 651 of the ridges 637 form a discontinuous rim at the proximal end 653 of the sleeve 630.

Figs. 7a-7f show details of yet another aerosol-generating device according to the present invention which comprises an insert sleeve 730 according to a fourth embodiment. Like the previous embodiment, the embodiment according to Figs. 7a-7f is also very similar to the embodiment shown in Figs.5a-5d. Therefore, identical or similar features are denoted with the same reference signs, yet incremented by 200. In contrast to the embodiment according to Figs. 5a-5d, the airflow channels 732 in the embodiment according to Figs. 7a- 7f do not extend all the way to the proximal edge 742 of the insert sleeve 730, but rather end in the proximal direction distal of the proximal edge 742. Thus, the airflow channel are accessible from the outside of the insert sleeve 730 only in a radially inward direction with respect to the length extension 731 of the insert sleeve 730, but not directly in the distal direction. This is achieved by a collar 739 which provides a closing-off of the airflow channels 732 in the proximal direction. As shown in Figs 7a-7b, the ridges 737 extend in the proximal direction to merge radially flush or substantially flush with the circumference of the collar 739. In this embodiment, air inlets 745 are provided inside the device. More specifically, the air inlets 745 are at least partially covered by the fixation ring 706 in a radial direction of the inert sleeve 730. Figs. 8a-8b show still another alternative embodiment of the insert sleeve 830 which is based on the embodiment shown in Fig.1a - Fig.4c. Therefore, identical or similar features are denoted with the same reference signs, yet incremented by 700. In contrast to the embodiment according to Fig.1a - Fig.4c, the insert sleeve 830 extends further in the distal direction beyond the proximal portion of the chamber 810. More specifically, the insert sleeve comprises three segments, namely, a first sleeve segment 856 comprising the contact portion 835, a second sleeve segment 857 comprising a non-contact portion 859 and a third sleeve segment 858 comprising a distal sleeve portion 860. The first sleeve segment 856, the second sleeve segment 857 and the third sleeve segment 858 are parts separate from each other. An inner cross-sectional area of the insert sleeve 830 in the noncontact portion 859 is larger than an inner cross-sectional area of the insert sleeve 830 in the contact portion 835, such that the sleeve inner surface in the non-contact portion 859 is distanced from the received article 870. This configuration is beneficial in reducing or avoiding undesired condensate effects on the outer surface of the article 870, which is particularly important with respect to the outer surface around the substrate element. The sleeve inner surface 834 in the distal sleeve portion 860 is in contact with the circumference of the aerosol-generating article 870, in particular with a circumference of a distal end portion in order to retain the article 870 in the chamber 810 and to position the article 870 in the radial direction. For both purposes, the sleeve inner surface 834 in the distal sleeve portion 860 comprises a plurality of protrusions configured to contact the aerosol-generating article 870. For example, the plurality of protrusions may comprise retention ribs.

Figs. 9a-9b show a fifth embodiment of the insert sleeve 130, which is similar to the two embodiments of the insert sleeve according to Figs. 1a-1d, 2a-2b and Figs. 2c-2d, respectively. Accordingly, similar or identical features are denoted with the same reference signs. While Figs. 1a-1d, 2a-2b and Figs. 2c-2d show embodiments of an insert sleeve 130 having twelve and five ridges 137, respectively, Figs. 9a-9b show an insert sleeve having ten ridges 137 and, accordingly ten airflow channels and ten through holes 149 or air inlets 145, respectively. Further in contrast to the embodiments shown in Figs. 1a-1d, 2a-2b and Figs. 2c-2d, the insert sleeve 130 shown in Figs. 9a-9b has a smaller length extension. In Figs. 9a-9b, the length extension of the insert sleeve may be, for example, in a range between 4.5 mm and 5 millimeter. As can be further seen in Figs. 9a-9b, one or more ringshaped ridges may be provided at the inner surface in the contact portion 135 that come into circumferentially closed contact with a circumference of the aerosol-generating article such as to exert an annular retention force to the article when it is received in the chamber. The inner diameter of the ring-shaped ridge(s) may vary along the axial direction of the insert sleeve. In particular, the inner cross-sectional shape of the ring-shaped ridge(s) may decrease, in particular smoothly decrease along the axial direction of the insert sleeve in the distal direction. Preferably, the inner cross-sectional shape of the ring-shaped ridge(s) may smoothly decrease in the distal direction starting from a maximum inner cross-sectional shape of the contact portion t135 towards a minimum inner cross-sectional shape and then increase again, in particular abruptly such as to form a sharp distal edge of the ring-shaped ridge.

Figs. 10a-10b show a sixth embodiment of the insert sleeve 730, which is similar to the embodiment of the insert sleeve shown in Figs. 7a-7b. Accordingly, similar or identical features are denoted with the same reference signs. Like in Figs. 7a-7b, the airflow channels 732 in the embodiment according to Figs. 10a-10b do not extend all the way to the proximal edge 742 of the insert sleeve 730, but rather end in the proximal direction distal of the proximal edge 742. Thus, the airflow channel are accessible from the outside of the insert sleeve 730 only in a radially inward direction with respect to the length extension 731 of the insert sleeve 730, but not directly in the distal direction. This is achieved by a collar 739 which provides a closing-off of the airflow channels 732 in the proximal direction. As shown in Figs. 7a-7b, the ridges 737 extend in the proximal direction to the collar 739, but do not merge radially flush with the circumference of the collar 739. In contrast to the embodiment shown in Figs. 7a-7b, the insert sleeve 730 shown in Figs. 10a-10b has a smaller length extension. Further in contrast, the insert sleeve 730 shown in Figs. 10a-10b has eight ridges 737 and, accordingly eight airflow channels 732 only, instead of twelve as in Figs. 7a-7b.

Figs. 11a-11 b show a seventh embodiment of the insert sleeve 930, which is similar to the embodiment of the insert sleeve 730 shown in Figs. 10a-10b. Accordingly, similar or identical features are denoted with the same reference signs, yet incremented by 200. Like in 10a-10b, the insert sleeve 930 according to Figs. 11a-11b has eight ridges 937 and, accordingly eight airflow channels 932. In contrast to the embodiment according to Figs. 10a-10b, adjacent ridges 937 and adjacent air flow channels 932 of the insert sleeve 930 according to Figs. 11a-11b have alternating larger and smaller widths. Further in contrast to the embodiment according to Figs. 10a-10b, the insert sleeve 930 comprises a support structure 955 which is formed by a ring member protruding beyond the ridges 937 in a radially outward direction. The ring-shaped support structure 955 is similar to, but stronger than the ring-shaped support structure 155 of the insert sleeve 130 shown in Figs. 1a-1d, 2a-2b and Figs. 2c-2d, respectively, thus providing a better thingness of the sealing member. However, the insert sleeve 930 shown in Figs. 11a-11b does not comprise a turned-over collar as do the insert sleeves in Figs. 1a-1d, 2a-2b and Figs. 2c-2d, respectively. Rather, the insert sleeve 930 according to Figs. 11a-11b comprises through holes 949, one for each airflow channel 932, which are formed between the ring-shaped support structure 955, the ridges 937 and the bottom of the airflow channels 932. Each through hole 949 provides an individual fluid communication for each airflow channel 932. More particularly, the through holes 949 form air inlets 945 allowing air to enter the proximal portion of the airflow path, formed by the airflow channels 932, from the outside of the insert sleeve 930 in a direction along the sleeve center axis 140, whereas in Figs. 1a-1d, 2a-2b and Figs. 2c-2d air enters the proximal portion of the airflow path, formed by the airflow channels 132, from the inside of the insert sleeve 130. Accordingly, the air inlets 945 in Figs. 11a-11b may be denoted as external air inlets 945, whereas the air inlets 145 in Figs. 1a-1d, 2a-2b and Figs. 2c-2d may be denoted as internal air inlets 145. Advantageously, the external air inlets 945 ensure that there is no contact between the airflow and the aerosol-generating article in a proximal portion of the chamber.

For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term "about". Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A ± 5 percent of A. Within this context, a number A may be considered to include numerical values that are within general standard error for the measurement of the property that the number A modifies. The number A, in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.

Claims

1. An aerosol-generating device for use with an aerosol-generating article, the device comprising a chamber within a device housing for removably receiving at least a portion of the aerosol-generating article, the chamber having a chamber inner surface and a proximal open end for insertion of the article into the chamber, the device further comprising an insert sleeve separate from the device housing, being fixedly arranged in the device such that at least a portion of the insert sleeve extends along at least a proximal portion of the chamber inner surface, wherein the insert sleeve comprises a sleeve outer surface and a sleeve inner surface, wherein in a contact portion of the insert sleeve the sleeve inner surface is configured to come into circumferentially closed contact with a circumference of the aerosol-generating article when received in the chamber, and wherein at least a proximal portion of an airflow path through the device extends along the sleeve outer surface.

2. The aerosol-generating device according to claim 1 , wherein the proximal portion of the airflow path is formed at least partially between the sleeve outer surface and the chamber inner surface.

3. The aerosol-generating device according to any one of the preceding claims, wherein the insert sleeve comprises a plurality of airflow channels arranged along a circumference of the sleeve outer surface, the airflow channels forming part of the proximal portion of the airflow path.

4. The aerosol-generating device according to claim 3, wherein the airflow channels are formed between adjacent ridges arranged spaced from each other along the circumference of the insert sleeve, the ridges preferably being in contact with the chamber inner surface.

5. The aerosol-generating device according to any one of the preceding claims, wherein the insert sleeve comprises an intake portion at a proximal end of the insert sleeve, the intake portion preferably comprising one or more air inlets for air to enter the proximal portion of the airflow path along the sleeve outer surface, in particular to enter the airflow channels on the sleeve outer surface.

6. The aerosol-generating device according to any one of claims 3 to 5, wherein the airflow channels end in the proximal direction distal of a proximal edge of the insert sleeve, thus being accessible, in particular from the outside of the insert sleeve, in a radially inward direction, in particular only in a radially inward direction with respect to the length extension of the insert sleeve. The aerosol-generating device according to any one of claims 3 to 6, wherein the airflow channels extend in the proximal direction to a proximal edge of the insert sleeve, thus being accessible from the outside of the insert sleeve in at least one of the distal direction and a radially inward direction with respect to the length extension of the insert sleeve. The aerosol-generating device according to any one of claims 3 to 7, wherein the insert sleeve comprises one or more through holes, in particular in the intake portion, the through holes allowing air to enter the proximal portion of the airflow path, in particular to enter the airflow channels, from the inside of the insert sleeve, in particular from the inside of the intake portion. The aerosol-generating device according to any one of claims 3 to 8, wherein the insert sleeve comprises one or more axial recesses in a proximal edge of the insert sleeve, the recesses allowing air to enter the proximal portion of the airflow path, in particular to enter the airflow channels, from the inside of the insert sleeve, in particular from the inside of the intake portion. The aerosol-generating device according to any one of claims 1 to 8, wherein the insert sleeve comprises a circumferential collar at the proximal end of the insert sleeve. The aerosol-generating device according to claim 10, wherein the circumferential collar provides a closing-off of the airflow channels in the proximal direction. The aerosol-generating device according to any of claim 10 or claim 11 , wherein the collar is a turned-over collar comprising a turned-over collar portion surrounding the intake portion spaced from the sleeve outer surface in the intake portion. The aerosol-generating device according to any one of the preceding claims, wherein the insert sleeve comprises a non-contact portion arranged distal to the contact portion, wherein an inner cross-sectional area of the insert sleeve in the non-contact portion is larger than an inner cross-sectional area of the insert sleeve in the contact portion. The aerosol-generating device according to the preceding claim 13, wherein the insert sleeve comprises a distal sleeve portion arranged distal to the non-contact portion, wherein the sleeve inner surface in the distal sleeve portion is configured to come into contact with a circumference of the aerosol-generating article, in particular with a circumference of a distal end portion of the aerosol-generating article, when received in the chamber, The aerosol-generating device according to claim 14, wherein the insert sleeve comprises a first sleeve segment comprising the contact portion, a second sleeve segment comprising the non-contact portion and a third sleeve segment comprising the distal sleeve portion, wherein the first sleeve segment, the second sleeve segment and the third sleeve segment are parts separate from each other.