Heater for an aerosol-generating device having a plurality of susceptor groups

Abstract

A heater assembly for an aerosol-generating device comprises a heating chamber (14) for heating an aerosol-forming substrate, a first set of susceptors (16) configured for heating a first heating zone (20) of the heating chamber, and a second set of susceptors (18) configured for heating a second heating zone (22) of the heating chamber. The first and second heating zones are arranged at different longitudinal positions of the heating chamber. The susceptors are mountable on a ridge-like common support base (30) and are not in physical contact with each other. The susceptors in the second set of susceptors (18) can be longer than the susceptors in the first set of susceptors (16) and are paddle-shaped, having a stem (46) and a heating surface (50).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a heater assembly for an aerosol-generating device. The present disclosure further relates to an aerosol-generating device. The present disclosure also relates to an aerosol-generating system comprising an aerosol-generating device and an aerosol-generating article. BACKGROUND

[0002] It is known to provide an aerosol-generating device for generating an inhalable vapour. Such devices can heat an aerosol-forming substrate contained in an aerosol-generating article without burning the aerosol-forming substrate. The aerosol-generating article can have a rod shape to be inserted into a heating chamber of the aerosol-generating device. A heating element is arranged in or around the heating chamber to heat the aerosol-forming substrate when the aerosol-generating article is inserted into the heating chamber of the aerosol-generating device.

[0003] During use, the aerosol-generating article should be held securely in the heating chamber. The aerosol-generating article should be held with sufficient force that it does not fall out of the heating chamber, as this would render the device unable to generate an aerosol.

[0004] It is known to use induction heating whereby an alternating current in an inductor coil induces an alternating magnetic field. This alternating magnetic field is referred to as an induction field because if a susceptor is electrically conductive, the alternating magnetic field induces an alternating ring current (eddy current) in the susceptor. If the susceptor is magnetic, hysteresis losses will occur in the susceptor. In a susceptor that is both electrically conductive and magnetic, both effects (eddy current and hysteresis losses) will cause the susceptor to heat. In general, a material that heats when penetrated by an alternating magnetic field is referred to as a susceptor. The heat generated in this way then propagates to the aerosol-generating substrate, causing it to heat and thus generate an aerosol. Some induction heating devices are designed to have multiple heating zones, i.e. the heating system is able to heat only a sub-portion of the overall consumable. This can for example allow a single consumable to be used multiple times, or allow a single consumable to provide a different user experience depending on which sub-portion is used to generate an aerosol, or simply to achieve a more consistent user experience over a longer period of time. It is known to use different inductor coils to heat different heating zones of a susceptor. SUMMARY

[0005] It is desirable to have an aerosol-generating device that can reduce the energy consumed by the heater assembly. It is desirable to have an aerosol-generating device that can selectively heat a particular heating zone of a plurality of heating zones. It is desirable to have an aerosol-generating device that can reduce the heat transfer between different heating zones. It is desirable to have an aerosol-generating device that can reduce the thermal mass of a susceptor.

[0006] It is also desirable to have an aerosol-generating device that can provide close thermal contact between susceptors and aerosol-forming substrate. It is desirable to have an aerosol-generating device that can securely hold an aerosol-generating article in a heating chamber. It is desirable to have an aerosol-generating device that can allow easy insertion and removal of an aerosol-generating article into and from a heating chamber.

[0007] According to embodiments of the present application, a heater assembly for an aerosol-generating device is provided. The heater assembly can include a heating chamber for heating an aerosol-forming substrate. The heater assembly can include a first set of susceptors configured for heating a first heating zone of the heating chamber. The heater assembly can include a second set of susceptors configured for heating a second heating zone of the heating chamber. The first heating zone and the second heating zone can be arranged at different longitudinal positions of the heating chamber.

[0008] According to embodiments of the present application, a heater assembly for an aerosol-generating device is provided. The heater assembly includes a heating chamber for heating an aerosol-forming substrate. The heater assembly includes a first set of susceptors configured for heating a first heating zone of the heating chamber. The heater assembly further includes a second set of susceptors configured for heating a second heating zone of the heating chamber. The first heating zone and the second heating zone are arranged at different longitudinal positions of the heating chamber.

[0009] By providing the heater assembly of the present application, energy consumed by the heater assembly can be reduced. By providing the heater assembly of the present application, a particular heating zone of a plurality of heating zones can be selectively heated. By providing the heater assembly of the present application, heat transfer between different heating zones can be reduced. By providing the heater assembly of the present application, thermal mass of susceptors can be reduced.

[0010] By providing the heater assembly of the present application, close thermal contact between susceptors and aerosol-forming substrate can be achieved. By providing the heater assembly of the present application, an aerosol-generating device that securely holds an aerosol-generating article in a heating chamber can be provided. By providing the heater assembly of the present application, an aerosol-generating device that allows easy insertion and removal of an aerosol-generating article into and from a heating chamber can be provided.

[0011] Preferably, the heater assembly is a component part of an aerosol-generating device.

[0012] The first heating zone can be arranged distally of the second heating zone with respect to a longitudinal axis of the heating chamber.

[0013] Having a separate set of susceptors for each heating zone can advantageously reduce thermal contact between susceptors of different heating zones. Thus, unintentional heat transfer between different heating zones can be reduced. The containment of heat within a particular heating zone can advantageously be improved. Selective heating of individual heating zones can be improved. Heat loss between heating zones can be reduced. Energy consumption can be reduced.

[0014] As used herein, the term 'a set of susceptors' refers to a plurality of susceptors, which means two or more susceptors within one set, for example 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, or 8 or more susceptors. Having a plurality of susceptors for each heating zone can reduce the total mass of susceptor material compared to having one large single susceptor for the entire heating zone. This can reduce one or both of the thermal mass and thermal inertia of the susceptor material of each heating zone. As a result, less energy can be required to heat the heating zones to a desired temperature. As a result, the heating zones can be heated to a desired temperature more quickly. Having a plurality of susceptors for each heating zone can improve the mechanical flexibility of the susceptor arrangement.

[0015] The susceptors in one or both of the first set of susceptors and the second set of susceptors can be flexible in a direction orthogonal to the longitudinal axis of the heating chamber for securely holding an aerosol-generating article after insertion into the heating chamber. As used herein, the direction orthogonal to the longitudinal axis of the heating chamber corresponds to the lateral direction.

[0016] The susceptors in one or both of the first set of susceptors and the second set of susceptors can be elongate along the longitudinal axis of the heating chamber. The longitudinal axis of the susceptors in one or both of the first set of susceptors and the second set of susceptors can be collinear with the longitudinal axis of the heating chamber. This can advantageously provide lateral flexibility of the susceptors for clamping an aerosol-generating article.

[0017] There can be gaps between individual susceptors in a set of susceptors. Thus, lateral airflow through the gaps can be possible.

[0018] One or both of the first set of susceptors and the second set of susceptors can be arranged circumferentially around the heating chamber.

[0019] The susceptors in the first set of susceptors and the susceptors in the second set of susceptors can be arranged alternately such that a susceptor in the first set is adjacent to two susceptors in the second set. The susceptors in the first set of susceptors and the susceptors in the second set of susceptors can be arranged alternately along a lateral circumferential direction such that a susceptor in the first set is adjacent to two susceptors in the second set in the lateral circumferential direction.

[0020] The susceptors in one or both of the first group of susceptors and the second group of susceptors can comprise several parts. The susceptor can comprise a stem for mounting the susceptor at a distal end of the susceptor to a support base. The susceptor can comprise a heating portion for heating an aerosol-forming substrate of an aerosol-generating article. The heating portion can comprise a heating surface. The heating surface can be a flat portion configured to be in close thermal contact with the aerosol-generating article. The susceptor can comprise a tip portion at a proximal end thereof. The tip portion can be curved in a transverse direction orthogonal to a longitudinal direction of one or both of the susceptor and the heating chamber. Due to the curved tip portion of the susceptor, a horn-shaped arrangement of the group of susceptors can result. This can facilitate insertion of the aerosol-generating article into the heating chamber.

[0021] A gap can be provided between the heating surface of a susceptor in the first group of susceptors and the heating surface of a susceptor in the second group of susceptors. A gap can be provided between the heating surfaces of susceptors within a group of susceptors.

[0022] At least a portion of the susceptors in one or both of the first group of susceptors and the second group of susceptors can comprise a curved shape along a longitudinal direction of the heating chamber. At least a portion of the susceptors in one or both of the first group of susceptors and the second group of susceptors can comprise an S-shape along a longitudinal direction of the heating chamber. The curved shape or the S-shape can allow the susceptors to be configured such that only the heating portion or the heating surface of the susceptors is in close thermal contact with the aerosol-generating article in the respective heating zone.

[0023] The susceptors in the second group of susceptors can be longer than the susceptors in the first group of susceptors, measured in parallel to a longitudinal axis of the heating chamber.

[0024] The susceptors of one or both of the first group of susceptors and the second group of susceptors can comprise a thinner distal portion and a wider proximal portion. The thinner distal portion can be configured for mounting the susceptors in a clamp in the device, e.g. in a common base. The thinner distal portion can add mechanical flexibility, which means bendability, to one or both of the first group of susceptors and the second group of susceptors. The thinner distal portion can reduce heat transfer to the mounting clamp. Due to the reduced heat transfer, the clamp can not need to be made of an expensive material capable of withstanding excessive heat and can be made of an inexpensive material such as hard plastic.

[0025] The susceptors in the second group of susceptors can form a paddle shape.

[0026] The heating surface of one or both of the susceptors in the first group of susceptors and the second group of susceptors can be arranged in a honeycomb pattern.

[0027] The shape of the susceptors in the first group of susceptors can be different from the shape of the susceptors in the second group of susceptors. The material of the susceptors in the first group of susceptors can be different from the material of the susceptors in the second group of susceptors.

[0028] The susceptor can be made entirely of inductively heatable material. A portion of the susceptor can comprise a magnetically inert material. As used herein, the term "magnetically inert material" refers to a material that does not substantially heat when penetrated by an alternating magnetic field. A portion of the susceptor can comprise a material that is not susceptor material. This means that the portion is free of any susceptor material that heats with penetration by a varying magnetic field. Only the heated portion or heated surface of the susceptor can comprise susceptor material. For example, the heated surface can be coated with susceptor material. Thus, in use, more energy of the varying magnetic field can be used to heat the heated surface.

[0029] The magnetically inert material can comprise minerals, epoxy, polyester, polyacrylamide, vinyl ester resin, wood, ceramic, alumina, zirconia, aramid, glass fiber, polyethylene, and glass-like materials.

[0030] As used herein, a portion of the susceptor that comprises susceptor material and is configured to inductively heat is referred to as a "susceptor element".

[0031] As used herein, a "susceptor element" is an electrically conductive element that heats when subjected to a varying magnetic field. This can be a result of eddy currents induced in the susceptor element, hysteresis losses, or both eddy currents and hysteresis losses. During use, the susceptor element is in thermal contact with or in close thermal proximity to an aerosol-forming substrate of an aerosol-generating article received in a heating chamber of a heater assembly of an aerosol-generating device. In this way, the aerosol-forming substrate is heated by the susceptor element to cause an aerosol to form.

[0032] Advantageously, providing a heating zone formed by a set of individual susceptors allows the size, position, or size and position of the heating zone to be easily changed by changing one or more of the size, position, shape, and pattern of the susceptors. When only a portion of the susceptors comprise susceptor elements, the remainder of the susceptors can be formed from a non-susceptor material, which can be lighter or cheaper than the susceptor material. Additionally, a portion of the susceptors other than the susceptor elements can be formed from a thermally insulating material. This can additionally allow heat generated in the susceptor elements to remain concentrated in the heating zone. It can also reduce heat lost to other components of the aerosol-generating device. For example, it can additionally reduce the extent to which the housing of the aerosol-generating device heats during use.

[0033] As used herein, the terms "thermally insulating" and "thermally insulative" refer to a material having a bulk thermal conductivity of less than about 50 milliwatts per meter Kelvin (mW / (m K)) at 23 °C and 50% relative humidity as measured using the Modified Transient Plane Source (MTPS) method.

[0034] The susceptor element can comprise a foil or film of susceptor material applied to the heating surface of the susceptor. For example, a foil or film of susceptor material glued or welded to the heating surface.

[0035] The susceptor element can be a susceptor coating deposited on the heating surface. For example, the susceptor coating can be applied or printed as a liquid onto the heating surface. The susceptor coating can be deposited on the heating surface by a vacuum deposition process such as evaporation deposition or sputtering. The susceptor coating can be deposited on the heating surface by electrodeposition.

[0036] The susceptor element can be formed of any material capable of being inductively heated to a temperature sufficient to aerosolise the aerosol-forming substrate. Suitable materials for the susceptor element include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminium, nickel, nickel-containing compounds, titanium, and composites of metallic materials. Preferably, the susceptor element comprises a metal or carbon. Advantageously, the susceptor element can comprise or consist of a ferromagnetic material, such as ferritic iron, ferromagnetic alloys (such as ferromagnetic steel or stainless steel), ferromagnetic particles and ferrites. Suitable susceptor elements can be aluminium or comprise aluminium. The susceptor element preferably comprises greater than 5%, preferably greater than 20%, more preferably greater than 50% or greater than 90% of a ferromagnetic or paramagnetic material. Preferably, the susceptor element can be heated to a temperature in excess of 250 degrees Celsius.

[0037] The susceptor element can comprise a metal or a metal alloy. The susceptor element can be formed of a metal or a metal alloy.

[0038] The susceptor element can comprise or be made of one or more of silicon carbide, molybdenum, graphite, stainless steel, stainless steel alloys, copper, copper tungsten alloys, copper molybdenum alloys and electroplated conductors (such as nickel, silver, gold, silver platinum alloys and silver palladium alloys). The susceptor can be made of one or more of silicon carbide, molybdenum, graphite and stainless steel.

[0039] At least a portion of the susceptor can comprise or be made of a shape memory material. This can facilitate temporary clamping of the aerosol-generating article.

[0040] The first group of susceptors and the second group of susceptors can be mounted on a common base arranged at the distal end of the heating chamber. The common base can be ridge-like. The common base can comprise or be made of a thermally insulating material. Thereby, heat transfer between the susceptors can be reduced. As described herein, preferred thermally insulating materials include, for example, heat-resistant plastics, glass or polymeric materials, preferably having air inclusions (such as fibrous materials, aerogels and foams).

[0041] The heater assembly comprises at least a first heating zone and a second heating zone. The heater assembly can comprise a plurality of heating zones. During use, different heating zones can be heated to different temperatures. The plurality of heating zones can be positioned directly adjacent to each other. The heater assembly can comprise different heating zones separated along the longitudinal axis of the heating chamber. This can allow the heating zones to be used to heat different portions of the aerosol-generating article proximate to different groups of susceptors. For example, different portions of the same aerosol-forming substrate or different aerosol-forming substrates or the aerosol-forming substrate and aerosol-former of the aerosol-generating article.

[0042] A plurality of heating zones spaced apart along the longitudinal axis of the heating chamber can allow the heating zones to be used to heat different portions of the aerosol-generating article proximate to different groups of susceptors without inadvertently heating adjacent portions of the aerosol-generating article. For example, the spaced apart aerosol-forming substrates are heated. For example, a first aerosol-forming substrate is heated with the first heating zone and a second aerosol-forming substrate is heated with the second heating zone without substantially heating the second aerosol-forming substrate with the first heating zone or substantially heating the first aerosol-forming substrate with the second heating zone.

[0043] The plurality of heating zones can be formed from the same susceptor material or materials. One or more of the heating zones can be formed from a susceptor having a different composition to the susceptor of at least one other heating zone and thus different susceptor properties. With this arrangement, the first heating zone and the second heating zone can provide different heating profiles due to the different susceptor properties of the first susceptor material and the second susceptor material. The amount of heat provided by each heating zone can be fine-tuned by selecting the part or parts of the susceptor or the susceptor material or materials forming each susceptor. This can also facilitate sequential heating of the susceptors. For example, by forming the heating zones from a susceptor material that heats optimally under an alternating current at a different frequency. The first heating zone and the second heating zone can have different temperature cycles.

[0044] The heater assembly can comprise a further set of susceptors and a further longitudinally separated heating zone. For example, the heater assembly can comprise a third set of susceptors configured for heating a third heating zone of the heating chamber. The heater assembly can comprise a fourth set of susceptors configured for heating a fourth heating zone of the heating chamber.

[0045] The heater assembly can comprise a first inductor coil for heating the first heating zone and a second inductor coil for heating the second heating zone.

[0046] The heater assembly can comprise a single inductor coil for heating both the first heating zone and the second heating zone.

[0047] The heater assembly can comprise one or more induction coils for heating at least a portion of the susceptor in one or both of the first and second groups of susceptors. The heater assembly can comprise a first induction coil for heating the first group of susceptors and a second induction coil for heating the second group of susceptors. The heater assembly can comprise a single induction coil for heating both the first and second groups of susceptors.

[0048] The magnetic axis of the one or more induction coils can be at an angle to the longitudinal axis of the heating chamber, i.e. not parallel. In preferred embodiments, the magnetic axis of the one or more induction coils is substantially parallel to the longitudinal axis of the heating chamber. This can facilitate a more compact arrangement. Preferably, at least a portion of the susceptor is substantially parallel to the magnetic axis of the one or more induction coils. This can facilitate uniform heating of the susceptor element or susceptor by the one or more induction coils. In particularly preferred embodiments, the susceptor is substantially parallel to the magnetic axis of the one or more induction coils and to the longitudinal axis of the heating chamber.

[0049] The present application further relates to an aerosol-generating device comprising a heater assembly as described herein.

[0050] The aerosol-generating device can comprise a controller connected to the one or more induction coils, and a power supply. The controller can be configured to control the supply of electrical power from the power supply to the induction coils. The controller can comprise a microprocessor, which can be a programmable microprocessor, a microcontroller or an application specific integrated chip (ASIC) or other circuitry capable of providing control. The controller can comprise other electronic components. The controller can be configured to regulate the supply of electrical current to the one or more induction coils. The electrical current can be supplied to the one or more induction coils continuously after the aerosol-generating device is activated, or can be supplied intermittently, such as on a puff-by-puff basis. The circuitry can advantageously comprise a DC / AC converter, which can comprise a class D or class E power amplifier. The controller can be configured for independently controlling the first and second heating zones. The controller can be configured for independently controlling the first induction coil for heating the first heating zone and the second induction coil for heating the second heating zone.

[0051] The present application further relates to an aerosol-generating system comprising: an aerosol-generating device comprising a heater assembly as described herein, and an aerosol-generating article comprising an aerosol-forming substrate. The aerosol-generating article can be configured to be at least partially inserted into the heating chamber.

[0052] The aerosol-generating article can comprise a first aerosol-forming substrate located at a first longitudinal position of the aerosol-generating article and configured to be heated by the first set of susceptor heaters at the first heating zone when the aerosol-generating article is inserted into the heating chamber. The aerosol-generating article can comprise a second aerosol-forming substrate located at a second longitudinal position of the aerosol-generating article and configured to be heated by the second set of susceptor heaters at the second heating zone when the aerosol-generating article is inserted into the heating chamber.

[0053] The aerosol-generating article can comprise a hollow tubular substrate portion comprising an aerosol-forming substrate. The hollow tubular substrate portion can be formed from a tubular tobacco mass.

[0054] As used herein, the term "aerosol-forming substrate" refers to a substrate capable of releasing volatile compounds that can form an aerosol. The volatile compounds can be released by heating or combusting the aerosol-forming substrate. As an alternative to heating or combustion, in some cases, the volatile compounds can be released by a chemical reaction or by a mechanical stimulus such as ultrasonic waves. The aerosol-forming substrate can be a solid or a liquid, or can comprise solid and liquid components. The aerosol-forming substrate can be part of an aerosol-generating article.

[0055] As used herein, the term "aerosol-generating article" refers to an article comprising an aerosol-forming substrate capable of releasing volatile compounds that can form an aerosol. The aerosol-generating article can be disposable.

[0056] As used herein, the term "aerosol-generating device" relates to a device that interacts with an aerosol-forming substrate to generate an aerosol. The aerosol-generating device can interact with one or both of an aerosol-generating article comprising an aerosol-forming substrate or a cartridge comprising an aerosol-forming substrate. In some examples, the aerosol-generating device can heat the aerosol-forming substrate to facilitate the release of volatile compounds from the substrate. Electrically operated aerosol-generating devices can comprise an atomiser, for example an electric heater, to heat the aerosol-forming substrate to form an aerosol.

[0057] As used herein, the term "aerosol-generating system" refers to the combination of an aerosol-generating device and an aerosol-forming substrate. When the aerosol-forming substrate forms part of an aerosol-generating article, the aerosol-generating system refers to the combination of the aerosol-generating device and the aerosol-generating article. In the aerosol-generating system, the aerosol-forming substrate and the aerosol-generating device cooperate to generate an aerosol.

[0058] As used herein, the term "longitudinal" is used to describe a direction along a heater assembly, aerosol-generating device, aerosol-generating article, or a major axis of a component of an aerosol-generating device or aerosol-generating article, while the term "lateral" is used to describe a direction perpendicular to the longitudinal direction. When referring to a heating chamber, the term "longitudinal" refers to the direction in which an aerosol-generating article is inserted into the chamber, while the term "lateral" refers to a direction perpendicular to the direction in which the aerosol-generating article is inserted into the chamber.

[0059] Generally, a heating chamber can have an open end in which an aerosol-generating article is inserted and a closed end opposite the open end. In such embodiments, the longitudinal direction is a direction extending between the open end and the closed end. In certain embodiments, the longitudinal axis of the heating chamber is parallel to the longitudinal axis of the aerosol-generating device. For example, the open end of the chamber is at the proximal end of the aerosol-generating device. In other embodiments, the longitudinal axis of the heating chamber is at an angle to the longitudinal axis of the aerosol-generating device, for example, transverse to the longitudinal axis of the aerosol-generating device. For example, where the open end of the heating chamber is positioned along a side of the aerosol-generating device such that the aerosol-generating article can be inserted into the heating chamber in a direction perpendicular to the longitudinal axis of the aerosol-generating device.

[0060] As used herein, the term "proximal" refers to the end or mouth end of the aerosol-generating device, and the term "distal" refers to the end opposite the proximal end. Likewise, with respect to a heating assembly or susceptor, the term "proximal" refers to the direction closest to the user during use, while the term "distal" refers to the direction away from the user during use. Correspondingly, each of the aerosol-generating device, heating assembly, susceptor, and heating chamber has a proximal end and an opposite distal end. When referring to a heating chamber or susceptor coil, the term "proximal" refers to the region closest to the open end of the heating chamber, while the term "distal" refers to the region closest to the closed end. The ends of the aerosol-generating device or heating chamber can also be referred to with respect to the direction of air flow through the aerosol-generating device. The proximal end can be referred to as the "downstream" end, while the distal end can be referred to as the "upstream" end.

[0061] As used herein, the term "length" refers to the major dimension in the longitudinal direction of a susceptor, heating chamber, aerosol-generating device, aerosol-generating article, or component of an aerosol-generating device or aerosol-generating article.

[0062] As used herein, the term "width" refers to the major dimension in the lateral direction at a particular location along the length of a susceptor, heating chamber, aerosol-generating device, aerosol-generating article, or component of an aerosol-generating device or aerosol-generating article. The term "thickness" refers to the dimension in the lateral direction perpendicular to the width.

[0063] A non-exhaustive list of non-limiting examples is provided below. Any one or more features of these examples can be combined with any one or more features of another example, embodiment, or aspect described herein.

[0064] Example A: A heater assembly for an aerosol-generating device, comprising

[0065] a heating chamber for heating an aerosol-forming substrate;

[0066] a first set of susceptors configured for heating a first heating zone of the heating chamber; and

[0067] a second set of susceptors configured for heating a second heating zone of the heating chamber;

[0068] wherein the first heating zone and the second heating zone are arranged at different longitudinal positions of the heating chamber.

[0069] Example B: The heater assembly according to Example A, wherein the first heating zone is arranged distally of the second heating zone relative to a longitudinal axis of the heating chamber.

[0070] Example C: The heater assembly according to Example A or Example B, wherein the susceptors of one or both of the first set of susceptors and the second set of susceptors are elongate along a longitudinal axis of the heating chamber.

[0071] Example D: The heater assembly according to any one of the preceding examples, wherein one or both of the first set of susceptors and the second set of susceptors are arranged circumferentially around the heating chamber.

[0072] Example E: The heater assembly according to Example D, wherein the susceptors of the first set of susceptors and the susceptors of the second set of susceptors are arranged alternately, such that a susceptor of the first set is adjacent to two susceptors of the second set.

[0073] Example F: The heater assembly according to any one of the preceding examples, wherein the susceptors of one or both of the first set of susceptors and the second set of susceptors are flexible in a direction orthogonal to a longitudinal axis of the heating chamber for securely holding an aerosol-generating article after insertion of the aerosol-generating article into the heating chamber.

[0074] Example G: The heater assembly according to any one of the preceding examples, wherein at least a portion of the susceptors of one or both of the first set of susceptors and the second set of susceptors comprise a curved shape along a longitudinal direction of the heating chamber.

[0075] Example H: The heater assembly according to Example G, wherein at least a portion of the susceptors in one or both of the first set of susceptors and the second set of susceptors comprise an S-shape along a longitudinal direction of the heating chamber.

[0076] Example I: The heater assembly according to any of the preceding examples, wherein the susceptors in the second set of susceptors are longer than the susceptors in the first set of susceptors, measured parallel to a longitudinal axis of the heating chamber.

[0077] Example J: The heater assembly according to any of the preceding examples, wherein the susceptors in the second set of susceptors comprise a thinner distal portion and a wider proximal portion.

[0078] Example K: The heater assembly according to any of the preceding examples, wherein the susceptors in the second set of susceptors form a paddle shape.

[0079] Example L: The heater assembly according to any of the preceding examples, wherein the heating surfaces of one or both of the first set of susceptors and the second set of susceptors are arranged in a honeycomb pattern.

[0080] Example M: The heater assembly according to any of the preceding examples, wherein a gap is provided between the heating surfaces of the susceptors in the first set of susceptors and the heating surfaces of the susceptors in the second set of susceptors.

[0081] Example N: The heater assembly according to any of the preceding examples, wherein a gap is provided between the heating surfaces of the susceptors within one set of susceptors.

[0082] Example O: The heater assembly according to any of the preceding examples, wherein the shape of the susceptors in the first set of susceptors is different from the shape of the susceptors in the second set of susceptors.

[0083] Example P: The heater assembly according to any of the preceding examples, wherein the material of the susceptors in the first set of susceptors is different from the material of the susceptors in the second set of susceptors.

[0084] Example Q: The heater assembly according to any of the preceding examples, wherein the first set of susceptors and the second set of susceptors are mounted on a common base arranged at a distal end of the heating chamber.

[0085] Example R: The heater assembly according to any of the preceding examples, comprising a first inductor coil for heating the first set of susceptors and a second inductor coil for heating the second set of susceptors.

[0086] Example S: The heater assembly according to any of Examples A to Q, comprising a single inductor coil for heating both the first set of susceptors and the second set of susceptors.

[0087] Example T: A heater assembly according to any one of the preceding examples, wherein at least a portion of the susceptor comprises or is made of one or more of silicon carbide, molybdenum, graphite, stainless steel, stainless steel alloys, copper, copper tungsten alloys, copper molybdenum alloys and electroplated conductors such as nickel, silver, gold, silver platinum alloys and silver palladium alloys.

[0088] Example U: A heater assembly according to any one of the preceding examples, wherein at least a portion of the susceptor comprises or is made of a shape memory material.

[0089] Example V: An aerosol-generating device comprising a heater assembly according to any one of the preceding examples.

[0090] Example W: An aerosol-generating system comprising an aerosol-generating device according to Example V and an aerosol-generating article comprising aerosol-forming substrate, wherein the aerosol-generating article is configured to be at least partially inserted into the heating chamber.

[0091] Example X: An aerosol-generating system according to Example W, wherein the aerosol-generating article comprises a first aerosol-forming substrate and a second aerosol-forming substrate, the first aerosol-forming substrate being located at a first longitudinal position of the aerosol-generating article and configured to be heated by the first set of susceptors at the first heating zone when the aerosol-generating article is inserted into the heating chamber, the second aerosol-forming substrate being located at a second longitudinal position of the aerosol-generating article and configured to be heated by the second set of susceptors at the second heating zone when the aerosol-generating article is inserted into the heating chamber.

[0092] Features described in relation to one embodiment can equally apply to other embodiments of the application. BRIEF DESCRIPTION OF DRAWINGS

[0093] The application will be further described, by way of example only, with reference to the accompanying drawings in which:

[0094] Figure 1 shows a heater assembly of the application;

[0095] Figure 2 a to 2f show individual susceptors;

[0096] Figure 3 show two sets of susceptors in an alternating arrangement; and

[0097] Figure 4a and 4b show an aerosol-generating article and an article inserted into a heater assembly of the application. DETAILED DESCRIPTION

[0098] Figure 1a and 1b A heater assembly 10 of the present invention as part of an aerosol-generating device is shown in cross-sectional view. The dashed line indicates a central longitudinal axis 12 of the heater assembly 10. The heater assembly 10 comprises a heating chamber 14 for heating an aerosol-forming substrate of an aerosol-generating article. Two groups of susceptors, namely a first group of susceptors 16 and a second group of susceptors 18, are arranged circumferentially in a distal portion of the heating chamber 14. Figure 1a and 1b The same heater assembly 10 is shown. However, Figure 1b It appears that the first group of susceptors 16 is configured for heating a first heating zone 20 of the heating chamber 14, while the second group of susceptors 18 is configured for heating a second heating zone 22 of the heating chamber 14. The first heating zone 20 and the second heating zone 22 are arranged at different longitudinal positions of the heating chamber 14. The heater assembly 10 further comprises a first inductor coil 24 for heating the first group of susceptors 16 and a second inductor coil 26 for heating the second group of susceptors 18. The first inductor coil 24 and the second inductor coil 26 are correspondingly arranged at different longitudinal positions of the heating chamber 14 to coaxially surround the susceptor arrangement. A thermal insulator tube 28 is coaxially provided between the inductor coils 24, 26 and the susceptors 16, 18.

[0099] The susceptors 16, 18 are mounted at a distal end of the heating chamber 14 on a ridge-like common support base 30. The heater assembly 10 further comprises a distal thermal insulator member 32, an air inlet 34, a sealing member 36 and a housing 38.

[0100] The individual susceptors 16, 18 are not in physical contact with each other. There is a gap between adjacent susceptors 16, 18. Thus, there is a gap between the susceptors 16, 18 of different groups of susceptors. Due to the gap between the susceptors 16, 18 of different groups, the heat transfer between the different heating zones is reduced.

[0101] There is also a longitudinal gap between the susceptors within a group. Due to the gap between the susceptors within a group of susceptors, it is made possible for a lateral air flow to pass through the gap between the susceptors from the air inlet 34 and into a central region of the heating chamber 14 at the central longitudinal axis 12. This can advantageously improve aerosol generation, in particular when an aerosol-generating article comprising a hollow tubular aerosol-forming substrate is inserted into the heating chamber 14.

[0102] Figure 2 a to 2f show Figure 1a and 1bthe individual susceptors 16, 18 of the two groups of susceptors of the heater assembly 10 of Fig. 1. Each susceptor 16, 18 of both the first group of susceptors 16 and the second group of susceptors 18 is elongated along the longitudinal axis of the heating chamber.

[0103] Figure 2 Figs. 1a to 2c show a front view, a side view and a top view of a susceptor 16 of the first group of susceptors, respectively. Figure 2 The front view of Fig. 1a shows the susceptor 16 comprising a stem 40, a heating surface 42 and a tip 44. In Figure 1a and 1b In the heater assembly of Fig. 1, the distal end of each susceptor 16 is mounted at the stem 40 to the common support base 30. When inserting an aerosol generating article into the heating chamber 14, the heating surface 42 is in close thermal contact with the aerosol-forming substrate of the aerosol generating article.

[0104] Figure 2 The side view of Fig. 1b and Figure 2 The top view of Fig. 1c shows that the tip 44 is inclined. This results in a trumpet shape at the proximal end of the circumferentially arranged set of first susceptors 16, thereby facilitating the insertion of an aerosol generating article.

[0105] Figure 2 Figs. 1d to 2f show a front view, a side view and a top view of a susceptor 18 of the second group of susceptors 18, respectively. The susceptors 18 of the second group of susceptors are longer than the susceptors 16 of the first group of susceptors, measured parallel to the longitudinal axis of the heating chamber. Figure 2 The front view of Fig. 1d shows that the susceptors 18 of the second group of susceptors 18 comprise a thinner distal portion and a wider proximal portion. The susceptors 18 form a paddle shape. The susceptors 18 comprise a stem 46, a curved portion 48, a heating surface 50 and a tip 52. In Figure 1a and 1b In the heater assembly of Fig. 1, the distal end of each susceptor 18 is mounted at the stem 46 to the common support base 30. The curved portion 48 has a curved shape along the longitudinal direction of the heating chamber. This results in a laterally protruding portion. In Figure 2 The curved form of the portion 48 is shown in the side view of Fig. 1e. In the assembled state, the portion 48 is curved away from the longitudinal center axis of the heating chamber. An S-shape of the susceptor 18 along the longitudinal direction of the heating chamber 14 is shown. Thereby, only the heating surface 50 is in close thermal contact with the aerosol-forming substrate of the aerosol generating article when inserting the aerosol generating article into the heating chamber 14. The second susceptors 18 advantageously do not contact and thus do not heat the aerosol generating article in the region of the first heating zone 20.

[0106] Figure 2 The side view of Fig. 1e and Figure 2The top view of f shows that the tips 52 are tilted. This results in a horn shape of the circumferentially arranged sets of second susceptors 18, which facilitates insertion of the aerosol generating article.

[0107] Figure 3 The alternating arrangement of the first and second susceptors 16, 18 in the heater assembly of Figure 1a and 1b is shown. Each susceptor 16 in the first set is adjacent to two susceptors 18 in the second set. Figure 3 It is also shown that the heating surfaces 42, 50 of the susceptors 16, 18 in the first and second sets are arranged in a honeycomb-like pattern. Figure 3 It is also shown that gaps between the individual susceptors. For ease of presentation, Figure 3 susceptors 16, 18 in a flat arrangement instead of a circumferential arrangement around the central axis 12 in the assembled state of Figure 1a and 1b are shown.

[0108] Due to the elongated shape of the susceptors, and the susceptors being mounted to the common support base 30 at their stems 40, 46, the susceptors are flexible in the transverse direction, particularly at their tips 44, 52. This spring-like flexibility of the susceptors 16, 18 facilitates insertion of the aerosol generating article into the heating chamber 14. In addition, the flexible susceptors 16, 18 provide an improved clamping and secure holding of the inserted aerosol generating article. The distance between the closest points of the heating surfaces 42, 50 and the central axis 12 can be smaller than the diameter of the aerosol generating article before the aerosol generating article is inserted into the heating chamber 14. However, when the aerosol generating article is inserted into the induction heating chamber 14, the spring-like properties of the susceptors 16, 18 push them transversely away from the central axis 12 and allow the aerosol generating article to be clamped in place without penetrating the aerosol generating article. Thus, the heater surfaces 42, 50 push transversely against the aerosol generating article to securely hold the aerosol generating article and provide a tight thermal contact. At the same time, the aerosol generating article can be gently removed from the heating chamber 14 by pulling it along the longitudinal axis 12. This can additionally be facilitated by the heater surfaces 42, 50 being configured to have a low coefficient of friction.

[0109] Figure 4a An aerosol generating article 54 for use with an aerosol generating device comprising the heater assembly of the present invention is shown. The aerosol generating article 54 comprises a hollow cylindrical tube comprising two portions of solid aerosol-forming substrate 56, 58 at its distal end, and a mouthpiece comprising a mouthpiece filter (not shown) at its proximal end 60.

[0110] Figure 4b Insertion of Figure 1a and1b heating chamber 14 of the heater assembly 10 of Figure 4a aerosol-generating article 54. The distal end of the aerosol-generating article 54 is inserted into the heating chamber 14 such that the hollow cylindrical tube of the aerosol-generating article 54 is circumferentially surrounded by the susceptor arrangement.

[0111] A first portion of the aerosol-forming substrate 56 is surrounded by and in close thermal contact with the heating surface 42 of the susceptor 16 in the first group of susceptors. The first portion of the aerosol-forming substrate 56 is arranged in the first heating zone 20. A second portion of the aerosol-forming substrate 58 is surrounded by and in close thermal contact with the heating surface 50 of the susceptor 18 in the second group of susceptors. The second portion of the aerosol-forming substrate 58 is arranged in the second heating zone 22.

[0112] During use, air can enter the air inlet 34 and then propagate laterally through the gap between the susceptors 16, 18 and further into the aerosol-forming substrate 56, 58. The formed aerosol can then propagate laterally into the hollow core of the aerosol-generating article 54 and then longitudinally towards the mouthpiece at the proximal end 60 of the aerosol-generating article 54, where a user can inhale the aerosol.

Claims

1. A heater assembly for an aerosol generating apparatus, comprising: Heating chamber used to heat the aerosol-forming matrix; A first set of receptors, consisting of two or more receptors, is configured to heat the first heating zone of the heating chamber; as well as A second set of receptors, consisting of two or more receptors, is configured to heat the second heating zone of the heating chamber; The first heating zone and the second heating zone are arranged at different longitudinal positions in the heating chamber; and One or both of the first group of receptors and the second group of receptors are elongated along the longitudinal axis of the heating chamber.

2. The heater assembly of claim 1, wherein one or both of the first set of sensors and the second set of sensors are arranged circumferentially around the heating chamber.

3. The heater assembly of claim 2, wherein the receptors in the first group of receptors and the receptors in the second group of receptors are arranged alternately such that the receptors in the first group of receptors are adjacent to two receptors in the second group of receptors.

4. The heater assembly according to claim 1 or claim 2, wherein one or both of the first set of sensors and the second set of sensors are flexible in a direction orthogonal to the longitudinal axis of the heating chamber, for securely holding the aerosol-generating article after it has been inserted into the heating chamber.

5. The heater assembly according to claim 1 or claim 2, wherein at least a portion of one or both of the first set of sensors and the second set of sensors comprises a curved shape along the longitudinal direction of the heating chamber.

6. The heater assembly according to claim 1 or claim 2, wherein, when measured parallel to the longitudinal axis of the heating chamber, the receptors in the second set of receptors are longer than the receptors in the first set of receptors.

7. The heater assembly of claim 1 or claim 2, wherein the receptor in the second set of receptors includes a thinner distal portion and a wider proximal portion, and wherein the proximal portion refers to the direction closest to the user during use, and the distal portion refers to the direction away from the user during use.

8. The heater assembly according to claim 1 or claim 2, wherein the receptors in the second set of receptors are formed in a paddle shape.

9. The heater assembly according to claim 1 or claim 2, wherein a gap is provided between the heating surface of the sensor in the first group of sensors and the heating surface of the sensor in the second group of sensors.

10. The heater assembly according to claim 1 or claim 2, wherein a gap is provided between the heating surfaces of the sensors within a set of sensors.

11. The heater assembly according to claim 1 or claim 2, wherein the shape of the receptors in the first group of receptors is different from the shape of the receptors in the second group of receptors.

12. The heater assembly according to claim 1 or claim 2, wherein the first set of sensors and the second set of sensors are mounted on a common base disposed at the distal end of the heating chamber.

13. An aerosol generating apparatus comprising a heater assembly according to any one of claims 1 to 12.

14. An aerosol generation system comprising the aerosol generation apparatus of claim 13 and an aerosol generation article, the aerosol generation article comprising an aerosol forming matrix, wherein the aerosol generation article is configured to be at least partially inserted into the heating chamber.

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