KR20250011109A - Heater assembly having heater mounting portion - Google Patents

Abstract

A heater assembly (10) for an aerosol generating device (86). The heater assembly comprises a tubular heating chamber (12) for heating an aerosol-forming substrate. The tubular heating chamber comprises a proximal flared end (54). The heater assembly further comprises a heater casing (16) arranged around the heating chamber. The heater casing comprises a proximal wall surface (48). The proximal wall surface comprises a circular groove (50) extending proximally from an inner surface of the proximal wall surface (52). The circular groove comprises a chamfered inner side wall surface. The chamfered inner side wall surface and the proximal flared end of the tubular heating chamber have matching shapes. The proximal flared end of the tubular heating chamber is mounted within the circular groove of the proximal wall surface. The present invention also relates to an aerosol generating device comprising a heater assembly, and an aerosol generating system comprising an aerosol generating device and an aerosol-forming substrate.

Description

Heater assembly having heater mounting portion

The present invention relates to a heater assembly for an aerosol generating device. The present invention further relates to an aerosol generating device. The present invention further relates to an aerosol generating system comprising an aerosol generating device and an aerosol forming article.

It is known to provide an aerosol-generating device for generating an inhalable vapor. The device can heat an aerosol-forming substrate to a temperature at which one or more components of the aerosol-forming substrate volatilize without burning the aerosol-forming substrate. The aerosol-generating substrate can be provided as part of an aerosol-generating article. The aerosol-generating article can have a rod shape for insertion of the aerosol-generating article into a cavity, such as a heating chamber, of the aerosol-generating device. When the aerosol-generating article is inserted into the heating chamber of the aerosol-generating device, a heating element can be arranged within or around the heating chamber to heat the aerosol-generating substrate.

The heating chamber may be arranged within the housing of the aerosol-generating device and may form part of an airflow passage through the aerosol-generating device. It is known to provide a seal around the airflow passage and between the heating chamber and the housing to prevent aerosol from leaking out of the airflow passage and into other parts of the aerosol-generating device (which may cause damage to the electronics of the device). The seal may be arranged in direct contact with the heating chamber and is typically formed from a heat-resistant polymer, such as silicone or polysiloxane. However, exposure of such a polymeric seal to the heating temperature of the heating chamber may produce undesirable byproducts which may contaminate the aerosol. Furthermore, such heating temperatures may degrade the seal over time.

An additional challenge encountered when sealing the airflow passages within an aerosol generating device is manufacturing tolerances. Variations in component dimensions due to manufacturing tolerances can result in poor fit between components, and potentially aerosol leakage gaps. Achieving a good seal fit between components typically requires tight manufacturing tolerances that may be difficult to achieve in rapid manufacturing processes such as injection molding. Additionally, the device can be accidentally dropped. This can change the position of the heating chamber relative to the housing. A change in position of the heating chamber can cause the heating chamber to no longer be sealingly connected to the housing. Impact loading of the heating chamber due to a dropped aerosol generating device can additionally structurally damage the mounting connection of the heating chamber within the housing of the aerosol generating device.

It would be desirable to provide a heater assembly for an aerosol-generating device having an improved sealing of the airflow path. It would be desirable to provide a heater assembly for an aerosol-generating device that allows for manufacturing tolerances. It would be desirable to provide a heater assembly for an aerosol-generating device that allows for manufacturing tolerances while providing an improved sealing of the airflow path. It would be desirable to provide a heater assembly for an aerosol-generating device that is resistant to shock, such as shock caused by accidental dropping. It would be desirable to provide a heater assembly for an aerosol-generating device where direct contact between the sealing and the heating chamber is minimal to zero.

In accordance with an embodiment of the present invention, a heater assembly for an aerosol-generating device is provided. The heater assembly can include a tubular heating chamber for heating an aerosol-forming substrate. The tubular heating chamber can include a proximal flared end. The heater assembly can further include a heater casing arranged around the heating chamber. The heater casing can include a proximal wall surface. The proximal wall surface can include a circular groove extending proximally from an inner surface of the proximal wall surface. The circular groove can include a chamfered inner side wall surface. The chamfered inner side wall surface and the proximal flared end of the tubular heating chamber can have matching shapes. The proximal flared end of the tubular heating chamber can be mounted within the circular groove of the proximal wall surface.

In accordance with an embodiment of the present invention, a heater assembly for an aerosol-generating device is provided. The heater assembly comprises a tubular heating chamber for heating an aerosol-forming substrate. The tubular heating chamber comprises a proximal flared end. The heater assembly further comprises a heater casing arranged around the heating chamber. The heater casing comprises a proximal wall surface. The proximal wall surface comprises a circular groove extending proximally from an inner surface of the proximal wall surface. The circular groove comprises a chamfered inner side wall surface. The chamfered inner side wall surface and the proximal flared end of the tubular heating chamber have matching shapes. The proximal flared end of the tubular heating chamber is mounted within the circular groove of the proximal wall surface.

By mounting the proximal flared end of the tubular heating chamber within a circular groove of a heater casing comprising a chamfered inner side wall surface having a matching shape, an improved sealing can be provided. By mounting the proximal flared end of the tubular heating chamber within a circular groove of a heater casing comprising a chamfered inner side wall surface having a matching shape, a heater assembly that allows for manufacturing tolerances can be provided. By mounting the proximal flared end of the tubular heating chamber within a circular groove of a heater casing comprising a chamfered inner side wall surface having a matching shape, a heater assembly that allows for manufacturing tolerances while providing improved sealing can be provided. By mounting the proximal flared end of the tubular heating chamber within a circular groove of a heater casing comprising a chamfered inner side wall surface having a matching shape, an impact resistant heater assembly can be provided. By mounting the proximal flared end of the tubular heating chamber within a circular groove of a heater casing having a chamfered inner side wall surface having a matching geometry, minimal to zero contact of the heating chamber to the seal may be required. Accordingly, the generation of hazardous or potentially hazardous constituents (HPHCs) during heating may be reduced or prevented.

The proximal wall surface can be perpendicular to the longitudinal axis of the heater assembly. The proximal flared end can have an inner diameter that increases in the proximal direction. The thickness of the material forming the proximal flared end can be constant. The proximal flared end can have a funnel shape with a diameter that increases in the proximal direction. Both the inner surface and the outer surface of the proximal flared end can be inclined at the same angle with respect to the longitudinal axis of the heater assembly.

The proximal flared end of the tubular heating chamber can be press-fitted into a circular groove of the heater casing. The proximal flared end of the tubular heating chamber can be secured to the circular groove of the heater casing. The proximal flared end of the tubular heating chamber can be attached to the circular groove of the heater casing.

The tubular heating chamber can be a hollow cylinder having at least one flared end, preferably a proximal flared end. The tubular heating chamber can be a hollow tube having at least one flared end, preferably a proximal flared end. The tubular heating chamber can have at least one expanding conical end, preferably a proximal expanding conical end. The proximal flared end can have an inside diameter measured in a direction perpendicular to the longitudinal axis of the heater assembly. The tubular heating chamber can have a central inside diameter measured at a center of the tubular heating chamber in a direction perpendicular to the longitudinal axis of the heater assembly. The inside diameter of the proximal flared end can be greater than the central inside diameter of the tubular heating chamber.

The tubular heating chamber can include a distal flared end. The distal flared end can have a diameter that increases distally. The distal flared end can be funnel-shaped with a diameter that increases distally. Both the inner surface and the outer surface of the distal flared end can be inclined at the same angle.

The tubular heating chamber can include a proximal flared end and a distal flared end. The tubular heating chamber can be flared at both ends. The distal flared end and the proximal flared end of the tubular heating chamber can have the same inside diameter. The distal flared end can be equivalent to the proximal flared end. The distal flared end can have the same shape as the proximal flared end. The tubular heating chamber bay is a hollow cylinder having a flared end. The tubular heating chamber can be a hollow cylinder having an enlarged conical end.

The heater assembly can further include a heater mounting portion. The heater casing can include a heater mounting portion. The heater mounting portion can be attached to the heater casing. The heater casing can coaxially surround the heater mounting portion. The heater mounting portion can be configured to receive one end of a tubular heating chamber. A flared end of the tubular heating chamber can be mounted within the heater mounting portion. A distal flared end of the tubular heating chamber can be mounted within the heater mounting portion. The distal flared end of the tubular heating chamber can be secured to the heater mounting portion. The distal flared end of the tubular heating chamber can be attached to the heater mounting portion. The heater mounting portion can be arranged upstream of the tubular heating chamber. The heater mounting portion can be tubular.

The heater casing, the tubular heating chamber, and the heater mounting portion can define an airflow path through the heater assembly. The heater casing, the tubular heating chamber, and the heater mounting portion can surround the airflow path through the heater assembly. The airflow path can be defined by an airflow channel. The airflow channel can be formed by an inner wall surface of the heater casing, the tubular heating chamber, and the heater mounting portion. The airflow channel can run along a longitudinal axis of the heater assembly. The airflow channel can be a linear airflow channel.

The heater mounting portion can include an additional circular groove extending distally from an inner proximal surface of the heater mounting portion at a proximal end. The inner proximal surface of the heater mounting portion can be perpendicular to a longitudinal axis of the heater assembly. The circular groove of the heater mounting portion can include a chamfered inner side wall surface. The chamfered inner side wall surface of the heater mounting portion can flare distally. The chamfered inner side wall surface of the heater mounting portion and the distal flared end of the tubular heating chamber can have matching shapes. The distal flared end of the tubular heating chamber can be mounted within the circular groove of the heater mounting portion.

Both the circular groove of the heater casing and the heater mounting portion can include chamfered internal side walls. The tubular heating chamber can include proximal and distal flared ends that can have a shape that matches the chamfered internal side walls of the heater casing and the heater mounting portion.

In accordance with an embodiment of the present disclosure, a heater assembly for an aerosol-generating device is provided. The heater assembly comprises a tubular heating chamber for heating an aerosol-forming substrate. The tubular heating chamber comprises a proximal flared end and a distal flared end. The heater assembly further comprises a heater casing arranged around the heating chamber. The heater casing comprises a proximal wall surface. The proximal wall surface comprises a circular groove extending proximally from an inner surface of the proximal wall surface. The circular groove comprises a chamfered inner side wall surface. The chamfered inner side wall surface and the proximal flared end of the tubular heating chamber have matching shapes. The proximal flared end of the tubular heating chamber is mounted within the circular groove of the proximal wall surface. The heater assembly further comprises a heater mounting portion. The heater mounting portion comprises an additional circular groove extending distally from an inner proximal surface of the heater mounting portion at the proximal end. The circular groove of the heater mounting portion comprises a chamfered inner side wall surface. The chamfered inner side wall surface of the heater mounting portion and the distal flared end of the tubular heating chamber have matching shapes. The distal flared end of the tubular heating chamber is mounted within a circular groove of the heater mounting portion.

The chamfered inner side wall surface can comprise at least one rib, preferably three ribs. The chamfered inner side wall surface can comprise two, three, four, five or six ribs. The chamfered inner side wall surface of the circular groove of the heater casing can comprise ribs, preferably two, three, four, five or six ribs. The chamfered inner side wall surface of the circular groove of the heater mounting portion can comprise ribs, preferably two, three, four, five or six ribs, more preferably three ribs. Both the chamfered inner side wall surface of the heater casing and the heater mounting portion can each comprise ribs, preferably three ribs.

At least one of the chamfered inner side walls may include at least one protrusion, preferably three protrusions.

The chamfered inner side wall surface of the heater casing can flare in the proximal direction. The chamfered inner side wall surface of the heater mounting portion can flare in the distal direction. At least one chamfered inner side wall surface can flare toward the bottom of the circular groove. The cross section of at least one circular groove can be a right trapezoid.

The chamfered inner side wall surface of the heater casing and the proximal flared end of the tubular heating chamber can be parallel. The chamfered inner side wall surface and the distal flared end of the heater mounting portion can be parallel. Both the chamfered inner side wall surface and the flared end can be parallel.

The chamfered inner side surface of the heater casing and the heater mounting portion, and the proximal and distal flared ends of the tubular heating chamber can have chamfer angles. The chamfer angle can be measured between a longitudinal axis of the heater assembly and a chamfer of the at least one chamfered inner side surface or the at least one flared end. The chamfered inner side surface of the heater casing can have a chamfer angle that is approximately the same as the proximal flared end of the tubular heating chamber. The chamfered inner side surface of the heater mounting portion can have a chamfer angle that is approximately the same as the distal flared end of the tubular heating chamber. The chamfer angles of the at least one chamfered inner side surface and the at least one flared end can both be approximately the same. The chamfer angles of the chamfered inner side surface and the flared end can have approximately the same absolute value.

The proximal flared end of the tubular heating chamber and the chamfered inner side wall surfaces of the heater casing can have a chamfer angle of from 20° to 45°, preferably from 25° to 40°, more preferably about 30°. The distal flared end of the tubular heating chamber and the chamfered inner side wall surfaces of the heater mounting portion can have a chamfer angle of from 20° to 45°, preferably from 25° to 40°, more preferably about 30°. The flared end of the tubular heating chamber and the chamfered inner side wall surfaces of the heater casing and the heater mounting portion can have a chamfer angle of from 20° to 45°, preferably from 25° to 40°, more preferably about 30°.

The proximal flared end, the distal flared end and the chamfered inner side wall surface of the heater casing and the heater mount can have lengths measured along the chamfers. The length of the proximal flared end of the tubular heating chamber and the chamfered inner side wall surface of the heater casing can be from 0.5 to 5 mm, preferably from 0.5 to 3 mm, more preferably from 0.5 to 2 mm, and most preferably about 1 mm. The length of the distal flared end of the tubular heating chamber and the chamfered inner side wall surface of the heater mount can be from 0.5 to 5 mm, preferably from 0.5 to 3 mm, more preferably from 0.5 to 2 mm, and most preferably about 1 mm. Accordingly, the contact area between the tubular heating chamber and the heater casing and between the tubular heating chamber and the heater mount can be provided to be sufficiently small to prevent potential generation of HPHCs during heating of the heater assembly.

The proximal flared end, the distal flared end and the chamfered inner sidewalls of the heater casing and heater mounting portion can have an axial length measured along the longitudinal axis of the heater assembly. The axial length can be at least 0.8 mm. The axial length can be less than or equal to 4 mm.

The proximal flared end, the distal flared end and the chamfered inner sidewalls of the heater casing and heater mounting portion can have a transverse length measured perpendicular to the longitudinal axis of the heater assembly. The transverse length can be at least 0.5 mm. The transverse length can be no greater than 2.5 mm.

The dimensions of the flared end and the chamfered inner sidewalls can provide improved impact resistance. The heater assembly can be part of an aerosol generating device. Such a device can be accidentally dropped. Upon such a drop, the device can be exposed to forces along the longitudinal axis of the device and thus along the heater assembly. The chamfer angle of the flared end of the tubular heating chamber can split the initial impact force along the longitudinal axis of the heater assembly into two perpendicularly smaller forces. When the magnitude of the initial force is equal to that generated when the device is dropped on a hard surface, the stress generated on the heater assembly by these two smaller forces can be withstood by the heater assembly. To ensure such resistance, the chamfer angle can be between 20° and 45°, preferably between 25° and 40°, more preferably about 30°.

The heater casing can be radially spaced from the tubular heating chamber and the heater mounting portion to define a hollow air space around the tubular heating chamber and the heater mounting portion. This provides thermal insulation of the tubular heating chamber. The heater casing can have an outside diameter measured in a direction orthogonal to a longitudinal axis of the heating assembly. The diameter of the heater casing can be greater than an outside diameter of the tubular heating chamber measured in the same direction. A ratio of the outside diameter of the heater casing to the outside diameter of the tubular heating chamber can be from 2 to 3.5. The heater casing can be a tubular heater casing. The tubular heater casing can be arranged coaxially around the tubular heating chamber.

The inner diameter of the tubular heating chamber can be substantially corresponding to or substantially equal to the outer diameter of the aerosol-generating article. In some embodiments, the inner diameter of the tubular heating chamber can be slightly smaller than the outer diameter of the aerosol-generating article such that the aerosol-generating article is compressed within the tubular heating chamber. For example, the outer diameter of the aerosol-generating article can be about 7.4 mm, and the inner diameter of the tubular heating chamber can be about 7.3 mm. The length of the tubular heating chamber can be substantially corresponding to or substantially equal to the length of the aerosol-forming substrate provided on the aerosol-generating article.

The heater casing can include a proximal heater casing and a distal heater casing. The proximal heater casing can include a proximal wall having a circular groove. The heater casing can be a two-part heater casing. The proximal heater casing can include an air outlet. The air outlet can be an opening for receiving an aerosol-generating article. The aerosol can escape through the opening through the aerosol-generating article received within the tubular heating chamber. The distal heater casing can include an air inlet. The tubular heating chamber can be in fluid communication with the air inlet. The tubular heating chamber can be in fluid communication with the air outlet. The tubular heating chamber can be in fluid communication with both the air inlet and the aerosol air to define an airflow path through the heater assembly.

The proximal heater casing can have an airflow channel. The airflow channel of the proximal heater casing can be in fluid communication with the air inlet. The distal heater casing can have an airflow channel. The airflow channel of the distal heater casing can be in fluid communication with the air outlet. The tubular heating chamber can have an airflow channel. The airflow channel of the tubular heating chamber can pass through the length of the tubular heating chamber. The heater mount can have an airflow channel. The airflow channel of the heater mount can pass through the thickness or length of the heater mount. The airflow channels of the proximal heating casing, the distal heater casing, the tubular heating chamber, and the heater mount can each be in fluid communication with one another to define an airflow path through the heater assembly.

The proximal heater casing and the distal heater casing can be attached to one another. The proximal and distal heater casings can be attached to one another by fasteners. The proximal and distal heater casings can be attached to one another by a plurality of fasteners. The plurality of fasteners can be symmetrically spaced around the proximal and distal heater casings. The fastener or the plurality of fasteners can comprise a threaded fastener, such as a screw. The fastener or the plurality of fasteners can comprise a snap-fit fastener.

The proximal heater casing and the distal heater casing can have lengths measured along the longitudinal axis of the heater assembly. The length of the proximal heater casing can be less than the length of the distal heater casing.

The proximal heater casing can include a proximal portion and a distal portion. The proximal portion and the distal portion can have an outer diameter measured in a direction perpendicular to the longitudinal axis of the heater assembly. The outer diameter of the proximal portion can be smaller than the outer diameter of the distal portion. The distal portion can include a proximal wall surface including a circular groove. The circular groove can have an outer diameter measured in a direction perpendicular to the longitudinal axis of the heater assembly. The outer diameter of the circular groove can be approximately the same as the outer diameter of the proximal portion of the proximal heater casing.

The distal heater casing can include a proximal portion and a distal portion. The proximal portion and the distal portion can have an outside diameter measured in a direction perpendicular to the longitudinal axis of the heater assembly. The outside diameter of the proximal portion can be greater than the outside diameter of the distal portion.

The airflow channel may be defined by the proximal portion of the proximal heater casing, the tubular heater tube, the heater mounting portion, and the distal portion of the distal heater casing.

The heater mount can include a proximal portion and a distal portion. The proximal portion can have a larger diameter measured perpendicular to the longitudinal axis of the heater assembly than the distal portion. The proximal portion can include a circular groove. The distal heater casing can include the heater mount. The distal heater casing can be a part of the distal heater casing. Alternatively, the heater mount can be mounted within the distal heater casing. The heater mount can be connected to the distal heater casing via a snap fit or a threaded engagement. The heater mount can be mounted within a distal opening of the distal heater casing. The proximal portion of the distal heater casing can include a distal wall surface. The distal wall surface can include a distal opening. The distal portion of the heater mount can be at least partially inserted into the distal opening of the distal heater casing.

A tubular heating chamber can be arranged between the proximal heater casing and the heater mount. The tubular heating chamber can be fitted between the proximal heater casing and the heater mount. The tubular heating chamber can be press-fitted into the proximal heater casing and the heater mount. The proximal flared end of the tubular heating chamber can be fitted within a proximal wall surface of the proximal heater casing, and the distal flared end of the tubular heating chamber can be fitted within a proximal portion of the heater mount. The matching shape of the chamfered inner side wall surfaces and the flared end can provide a sealed connection when the tubular heating chamber is fitted between or press-fitted within the proximal heater casing and the heater mount.

When the heater mounting portion is mounted within the distal opening of the distal heater casing, the seal can be arranged between the heater mounting portion and an inner surface of the distal heater casing. When the heater mounting portion is mounted within the distal opening of the distal heater casing, the seal can be mounted between the heater mounting portion and an inner surface of the distal heater casing. The seal can be arranged between a distal end of a proximal portion of the heater mounting portion and a distal wall surface of the proximal portion of the distal heater casing.

The seal can be elastic. The seal can be formed of any suitable material. The seal can comprise an elastic material. The seal can comprise a polymer. The seal can comprise an elastomeric polymer. The seal can comprise or be formed of any suitable polymer, including but not limited to ethylene propylene diene monomer (EPDM) rubber or silicone. The seal can be an O-ring. The O-ring can have a diameter measured in a direction perpendicular to the longitudinal axis of the heater assembly. The diameter of the O-ring can be approximately equal to or smaller than an outer diameter of a proximal portion of the heater mounting portion measured in the same direction.

The seal may be compressed when the heater assembly is assembled. The seal may be compressed between the heater mounting portion and the distal heater casing when the heater assembly is assembled.

The seal can have a Shore hardness of from 30 A to 90 A, preferably from 50 A to 80 A, more preferably about 70 A. These values of Shore hardness have been found to be soft enough to absorb manufacturing tolerances, yet hard enough to still provide sufficient strength to the heater assembly for airflow path sealing and heater assembly integrity. The Shore hardness can be determined by the technical standard ISO868 Type A.

The seal can comprise any suitable shape. The seal can comprise a shape that conforms to the shape of the heater mounting portion. The seal can comprise a shape that conforms to the shape of one of the proximal and distal heater casings. The seal can comprise an O-ring. The seal can have any suitable cross-sectional shape in a longitudinal plane of the heater assembly, including but not limited to a circular cross-sectional shape, or a cross-sectional shape having two opposing flat surfaces, such as a square or rectangular cross-sectional shape.

The seals can have an uncompressed thickness or diameter of from 0.5 mm to 2 mm. The seals can have an uncompressed thickness or diameter of about 1 mm. These uncompressed thicknesses have been found to be particularly effective in absorbing manufacturing tolerances and providing airflow path sealing and heater assembly integrity.

An advantage of mounting the seal between the heater casing and the heater mounting portion rather than between the heater casing and the tubular heating chamber is that contact between the seal and the heating chamber is avoided. Furthermore, the seal is advantageously arranged to be spaced apart or at a distance from the tubular heating chamber. This distance between the tubular heating chamber and the seal means that the seal is kept at a lower temperature than the tubular heating chamber and does not overheat. Since the seal is not subject to high thermal stresses, an improved sealing of the airflow path through the heater assembly can be achieved.

The heater assembly of the present disclosure is also less sensitive to manufacturing tolerances because the seal can absorb at least a portion of the manufacturing tolerances to achieve an improved seal. Additionally, the matching geometry of the chamfered inner sidewalls and the flared ends can provide for precise alignment and maintenance of the heater casing, tubular heating chamber, and heater mounting portion.

The proximal heater casing, the distal heater casing, the tubular heating chamber, the heater mounting portion, and the sealing portion may surround an air space. The proximal heater casing, the distal heater casing, the tubular heating chamber, the heater mounting portion, and the sealing portion may surround a sealed space. The sealed space may be hollow. Alternatively or additionally, the sealed space may include an insulating material.

When the chamfered inner side wall surface of the heater casing and the heater mounting portion each include at least one rib, preferably three ribs, the proximal heater casing, the distal heater casing, the tubular heating chamber, the heater mounting portion and the sealing portion can surround an air space. When the chamfered inner side wall surface of the heater casing and the heater mounting portion each include at least one rib, preferably three ribs, the proximal heater casing, the distal heater casing, the tubular heating chamber, the heater mounting portion and the sealing portion can surround an air space. The air space can improve the overall heating efficiency of the heater assembly.

The ribs in combination with the O-rings can provide a hermetic seal. The ribs in combination with the O-rings can limit the possibility of air leakage out of the air space. Alternatively or additionally, the ribs in combination with the O-rings can limit the possibility of air leakage from the airflow path into the heater casing. The ribs and O-rings can absorb manufacturing tolerances. Accordingly, the seal can be little or not affected by manufacturing tolerances.

A heater assembly comprising a two-part heater casing, a tubular heating chamber having flared ends mounted within the proximal heater casing, and a heater mounting portion arranged on a sealing portion provides a less complex assembly while allowing for manufacturing tolerances and providing a good seal.

The tubular heating chamber can comprise a metal. The tubular heating chamber can be manufactured from a metal. The tubular heating chamber can be manufactured from stainless steel.

At least one of the wall surface of the heater casing and the heater mounting portion may comprise a plastic material. At least one of the wall surface of the heater casing and the heater mounting portion may be made of a plastic material. The plastic material may be polyaryl ether ketone (PAEK), polyether ether ketone (PEEK), and polyphenylene sulfone (PPSU), and more preferably polyphenylene sulfone (PPSU).

In one embodiment of the present invention, a heater assembly comprises a tubular heating chamber made of metal, a heater casing and a heater mounting portion made of a plastic material, and a seal between the heater mounting portion and the heater casing. Additionally, the tubular heating chamber comprises proximal and distal flared ends mounted within chamfered inner sidewalls of the heater casing and the heater mounting portion. The heater assembly can reduce contact between the metal tubular heating chamber and the plastic heater casing and the plastic heater mounting portion while providing a sealed connection. Direct contact of the metal tubular heating chamber and the seal is prevented. Accordingly, a heater assembly is provided which can reduce or prevent the occurrence of HPHC.

The tubular heating chamber can have an elongated shape. The length measured along the longitudinal axis of the heater assembly can be greater than the diameter of the tubular heating chamber measured in the same direction. The heating chamber can be an elongated hollow tube.

The heater assembly may further include a heating element. The heating element may be arranged at least partially around the heating chamber. The heating element may include one or more electrically conductive tracks on an electrically insulating substrate. The heating element may be flexible. The heating element may be wrapped at least partially around the tubular heating chamber. The heating element may be arranged between the heating casing and the tubular heating chamber.

Alternatively, the distal heater casing may include a circular groove having a chamfered inner side wall surface, the distal flared end of the tubular heating chamber may be mounted within the circular groove, and the proximal flared end may be mounted within a heater mounting portion mounted within the proximal heater casing.

The present invention further relates to an aerosol-generating device comprising a heater assembly as described herein. Preferably, the aerosol-generating device comprises a power supply configured to supply power to the heating element. The power supply preferably comprises a power source. Preferably, the power supply is a battery, such as a lithium ion battery. Alternatively, the power supply may be another form of charge storage device, such as a capacitor. The power supply may require recharging. For example, the power supply may have sufficient capacity to continuously generate an aerosol for a period of about 6 minutes, or a multiple of 6 minutes. In another example, the power supply may have sufficient capacity to allow a predetermined number of puffs or individual activations of the heater assembly.

The power supply may include control electronics. The control electronics may include a microcontroller. The microcontroller may preferably be a programmable microcontroller. The electrical circuit may include additional electronic components. The electrical circuit may be configured to regulate the supply of power to the heater assembly. Power may be supplied continuously to the heater assembly after the system is activated, or intermittently, for example, each time a puff is made. Power may be supplied to the heater assembly in the form of pulses of current.

The present invention also relates to an aerosol-generating system comprising an aerosol-generating device and an aerosol-generating article. The aerosol-generating article may comprise a substrate portion comprising an aerosol-forming substrate. The aerosol-generating article may be configured to be at least partially inserted into a tubular heating chamber.

The aerosol-generating article can include a substrate portion comprising an aerosol-forming substrate. The substrate portion can have a length that is shorter than or equal to the length of the heating element. The substrate portion can have a length that is greater than the length of the heating element. The substrate portion can have a length that is longer than the length of the heating element but shorter than the length of the heating chamber. The substrate portion can have a length that is equal to or greater than the length of the heating chamber. The aerosol-generating article can include the substrate portion and additionally a mouthpiece portion. The mouthpiece portion can be positioned at a proximal end of the aerosol-generating article. The mouthpiece portion can include a filter.

As used herein, the terms "upstream" and "downstream" are used to describe the relative positions of components, or portions of components, of the aerosol-generating device with respect to the direction in which air flows through the aerosol-generating device during use thereof. An aerosol-generating device according to the present invention comprises a proximal end from which, when in use, the aerosol exits the device. The proximal end of the aerosol-generating device may also be referred to as the mouth end or the downstream end. The mouth end is downstream of the distal end. The distal end of the aerosol-generating article may be referred to as the upstream end. Components, or portions of components, of the aerosol-generating device may be described as being upstream or downstream of one another based on their relative positions with respect to the airflow path of the aerosol-generating device.

The proximal end of the heater assembly according to the present invention is configured to be arranged within the aerosol generating device in a direction toward the mouth end or downstream end of the device. The distal end of the heater assembly according to the present invention is configured to be arranged within the aerosol generating device in a direction toward the distal end or upstream end of the device. The longitudinal axis of the tubular heating chamber can extend between the proximal end of the heating chamber and the distal end of the heating chamber. The longitudinal axis of the tubular heating chamber can extend between the proximal end of the heater assembly and the distal end of the heater assembly.

In all aspects of the present invention, the heating element can comprise an electrically resistive material. Suitable electrically resistive materials include, but are not limited to, semiconductors such as doped ceramics, electrically "conductive" ceramics (e.g., molybdenum disilicide, etc.), carbon, graphite, metals, metal alloys, and composite materials comprising ceramic materials and metallic materials. Such composite materials can include doped ceramics or undoped ceramics.

As described, in any of the embodiments of the present disclosure, the heating element may be part of a heating chamber of a heater assembly for an aerosol-generating device. The heater assembly may include an internal heater, an external heater, or both internal and external heaters, where “internal” and “external” are relative to the aerosol-forming substrate. The internal heating element may take any suitable form. For example, the internal heating element may take the form of a heating blade. Alternatively, the internal heater may take the form of a casing or substrate having different electrically conductive portions, or an electrically resistive metal tube. Alternatively, the internal heating element may be one or more heating needles or rods passing through the center of the aerosol-forming substrate. Other alternatives include heating wires or filaments, such as nickel-chromium (Ni-Cr), platinum, tungsten or alloy wires, or heating plates. Optionally, the internal heating element may be deposited within or on a rigid carrier material. In one such embodiment, the electrically resistive heating element may be formed using a metal having a defined relationship between temperature and resistivity. In such exemplary devices, the metal may be formed as tracks on a suitable insulating material, such as a ceramic material, and then embedded within another insulating material, such as glass. A heater formed in this manner may be used to both heat the heating element during operation and to monitor the temperature of the heating element.

The external heating element may take any suitable form. For example, the external heating element may take the form of one or more flexible heating foils on a dielectric substrate, such as polyimide. The flexible heating foils may be shaped to conform to the periphery of the substrate receiving cavity. Alternatively, the external heating element may take the form of a metal grid or grids, a flexible printed circuit board, a molded interconnect device (MID), a ceramic heater, a flexible carbon fiber heater, or may be formed using a coating technique, such as plasma vapor deposition, on a substrate of a suitable shape. The external heating element may also be formed using a metal having a defined relationship between temperature and resistivity. In such an exemplary device, the metal may be formed as a track between two layers of a suitable insulating material. The external heating element formed in this manner may be used both to heat the external heating element and to monitor the temperature of the external heating element during operation.

The heating element advantageously heats the aerosol-forming substrate by heat conduction. The heating element may be in at least partial contact with the substrate or the carrier on which the substrate is deposited. Alternatively, heat from either the internal or external heating element may be conducted to the substrate by the heat-conductive element.

During operation, the aerosol-forming substrate may be fully contained within the aerosol-generating device. In this case, the user may puff over the mouthpiece of the aerosol-generating device. Alternatively, during operation, the smoking article comprising the aerosol-forming substrate may be partially contained within the aerosol-generating device. In this case, the user may puff directly from the smoking article.

The heating element may be configured as an induction heating element. The induction heating element may comprise an induction coil and a susceptor. Typically, the susceptor is a material capable of generating heat when penetrated by an alternating magnetic field. According to the invention, the susceptor may be electrically conductive or magnetic, or both electrically conductive and magnetic. The alternating magnetic field generated by one or more induction coils heats the susceptor, which in turn transfers the heat to the aerosol-forming substrate so that an aerosol is formed. The heat transfer may be primarily by conduction of heat. This heat transfer is best when the susceptor is in intimate thermal contact with the aerosol-forming substrate. When an induction heating element is used, the induction heating element may be configured as an internal heating element as described herein or as an external heater as described herein. When the induction heating element is configured as an internal heating element, the susceptor element is preferably configured as a pin or blade for penetrating the aerosol-generating article. When the induction heating element is configured as an external heating element, the susceptor element is preferably configured as a cylindrical susceptor at least partially surrounding the cavity or forming a side wall surface of the cavity.

As used herein, the term "aerosol-forming substrate" refers to a substrate capable of releasing a volatile compound capable of forming an aerosol. The volatile compound may be released by heating or burning the aerosol-forming substrate. As an alternative to heating or burning, in some cases the volatile compound may be released by a chemical reaction or by mechanical stimulation, such as ultrasound. The aerosol-forming substrate may be a solid or a liquid, or may include both solid and liquid components. The aerosol-forming substrate may be part of an aerosol-generating article.

The aerosol-forming substrate can comprise nicotine. The nicotine-containing aerosol-forming substrate can be a nicotine salt matrix.

The aerosol-forming substrate can comprise a plant-based material. The aerosol-forming substrate can comprise tobacco. The aerosol-forming substrate can comprise a tobacco-containing material comprising volatile tobacco flavouring compounds that are released from the aerosol-forming substrate when heated. Alternatively, the aerosol-forming substrate can comprise a non-tobacco material. The aerosol-forming substrate can comprise a homogenised plant-based material. The aerosol-forming substrate can comprise a homogenised tobacco material. The homogenised tobacco material can be formed by agglomerating particulate tobacco.

The aerosol-forming substrate may comprise at least one aerosol former. The aerosol former is any suitable known compound or mixture of compounds which, when used, facilitates the formation of a dense, stable aerosol and is substantially resistant to thermal degradation at the operating temperature of the device. Suitable aerosol formers are well known in the art and include, but are not limited to, polyhydric alcohols such as triethylene glycol, 1,3-butanediol and glycerin; esters of polyhydric alcohols such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Preferred aerosol formers are polyhydric alcohols or mixtures thereof, such as triethylene glycol, 1,3-butanediol. Preferably, the aerosol former is glycerin. When present, the homogenized tobacco material may have an aerosol former content of greater than 5 weight percent on a dry weight basis, preferably from 5 weight percent to 30 weight percent on a dry weight basis. The aerosol forming substrate may include other additives and ingredients, such as flavourings.

As used herein, the term "aerosol-generating article" refers to an article comprising an aerosol-forming substrate capable of releasing a volatile compound capable of forming an aerosol. The aerosol-generating article may be disposable.

As used herein, the term "aerosol-generating device" refers 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 and 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. An electrically operated aerosol-generating device can include an atomizer, such as an electric heater, that heats the aerosol-forming substrate to form an aerosol.

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 an aerosol-generating system, the aerosol-forming substrate and the aerosol-generating device cooperate to generate an aerosol.

A non-exhaustive list of non-limiting examples is provided below. Any one or more features of these examples may be combined with any one or more features of any other embodiment, implementation, or aspect described herein.

Example ex1. A heater assembly for an aerosol generating device,

A tubular heating chamber for heating an aerosol forming substrate, said tubular heating chamber comprising a proximal flared end; and

A heater assembly comprising a heater casing arranged around the heating chamber, wherein the heater casing comprises a proximal wall surface, the proximal wall surface comprises a circular groove extending proximally from an inner surface of the proximal wall surface, the circular groove comprises a chamfered inner side wall surface, the chamfered inner side wall surface and the proximal flared end of the tubular heating chamber have matching shapes, and the proximal flared end of the tubular heating chamber is mounted within the circular groove of the proximal wall surface.

Example ex2. In Example ex1, the heater assembly has a chamfered inner side wall surface of the heater casing that flares out in the proximal direction.

Example ex3. A heater assembly in any of the aforementioned embodiments, wherein the tubular heating chamber comprises a distal flared end.

Example ex4. A heater assembly according to Example ex3, further comprising a heater mounting portion, wherein the distal flared end of the tubular heating chamber is mounted within the heater mounting portion.

Example ex5. In Example ex4, a heater assembly, wherein the heater casing, the tubular heating chamber, and the heater mounting portion define an airflow path through the heater assembly.

Example ex6. A heater assembly in any one of examples ex4 or ex5, wherein the heater mounting portion includes an additional circular groove extending distally from an inner proximal surface of the heater mounting portion at a proximal end, the circular groove including a chamfered inner side wall surface, the chamfered inner side wall surface flares distally, the chamfered inner side wall surface and the distal flared end of the tubular heating chamber have matching shapes, the distal flared end of the tubular heating chamber being mounted within the circular groove of the heater mounting portion.

Example ex7. A heater assembly in any of the above-described embodiments, wherein one or both of the chamfered inner side wall surface of the proximal wall surface and the chamfered inner side wall surface of the heater mounting portion include at least one rib, preferably three ribs.

Example ex8. A heater assembly in any one of the above-described embodiments, wherein the chamfered inner side wall surface of the heater casing has the same chamfer angle as the proximal flared end of the tubular heating chamber.

Example ex9. In Example ex8, the heater assembly wherein the proximal flared end of the tubular heating chamber and the chamfered inner side wall surface of the heater casing have a chamfer angle of 20° to 45°, preferably 25° to 40°, more preferably about 30°.

Example ex10. A heater assembly in any one of the above-described embodiments, wherein the length of the proximal flared end of the tubular heating chamber and the chamfered inner side wall surface of the heater casing is 0.5 to 5 mm, preferably 0.5 to 3 mm, more preferably 0.5 to 2 mm, and most preferably about 1 mm.

Example ex11. A heater assembly in any one of the above-described embodiments, wherein the heater casing is a tubular heater casing, and preferably, the tubular heater casing is arranged coaxially around the tubular heating chamber.

Example ex12. A heater assembly in any one of the above-described embodiments, wherein the heater casing comprises a proximal heater casing and a distal heater casing, and the proximal heater casing comprises a proximal wall surface having the circular groove.

Example ex13. A heater assembly according to Example ex12, wherein the proximal heater casing comprises an air outlet and the distal heater casing comprises an air inlet.

Example ex14. A heater assembly further comprising a heater mounting portion of Example ex4 in any one of Examples ex12 or ex13, wherein the distal heater casing comprises the heater mounting portion, or the heater mounting portion is mounted within a distal opening of the distal heater casing.

Example ex15. In Example ex14, the tubular heating chamber is fitted between the proximal heater casing and the heater mounting portion or is press-fitted therein, the heater assembly.

Example ex16. A heater assembly in any one of examples ex14 or ex15, wherein the heater mounting portion is mounted within the distal opening of the distal heater casing, and the sealing portion is arranged between the heater mounting portion and the inner surface of the distal heater casing.

Example ex17. In Example ex16, a heater assembly, wherein one or both of the chamfered inner side wall surface of the proximal wall surface and the chamfered inner side wall surface of the heater mounting portion comprise at least one rib, preferably three ribs, and the proximal heater casing, the distal heater casing, the tubular heating chamber, the heater mounting portion and the sealing portion surround an air space, preferably the air space is an airtight space, more preferably the airtight space is hollow.

Example ex18. A heater assembly in any one of the above-described embodiments, wherein the tubular heating chamber is made of metal, preferably made of stainless steel.

Example ex19. A heater assembly in any one of examples ex4 or ex18, wherein at least one of the wall surface of the heater casing and the heater mounting portion is made of a plastic material, preferably polyaryl ether ketone (PAEK), polyether ether ketone (PEEK), or polyphenylene sulfone (PPSU), more preferably polyphenylene sulfone (PPSU).

Example ex20. A heater assembly according to any one of the above-described embodiments, wherein the tubular heating chamber has an elongated shape, preferably, the tubular heating chamber is an elongated hollow tube.

Example ex21. A heater assembly according to any of the preceding embodiments, further comprising a heating element, preferably wherein the heating element is at least partially arranged around the tubular heating chamber.

Example ex22. A heater assembly according to Example ex21, wherein the heating element comprises one or more electrically conductive tracks on an electrically insulating substrate.

Example ex23. A heater assembly according to any one of examples ex21 or ex22, wherein the heating element is flexible and at least partially wrapped around the tubular heating chamber.

Example ex24. An aerosol generating device comprising a heater assembly according to any one of the above-described examples.

Example ex25. An aerosol-generating system comprising an aerosol-generating article comprising an aerosol-generating device and a substrate portion including an aerosol-forming substrate of ex24, wherein the aerosol-generating article is configured to be at least partially inserted into the tubular heating chamber.

Features described in connection with one embodiment may equally be applied to other embodiments of the invention.

The present invention will now be further described, by way of example only, with reference to the accompanying drawings.
FIG. 1 illustrates one embodiment of a heater assembly for an aerosol generating device;
Figures 2a, 2b, 2c and 2d each show a flared end of a tubular heating chamber having a chamfered inner side wall surface;
Figure 3 shows one embodiment of an aerosol generating device including a heater assembly.

FIG. 1 shows a cross-section of a heater assembly (10). The heater assembly (10) includes a tubular heating chamber (12) and a heater casing (14) arranged around the tubular heating chamber (12). The heater casing (14) includes a proximal heater casing (16) and a distal heater casing (18). The proximal heater casing (16) includes a proximal portion (20) and a distal portion (22). The proximal portion (20) has a smaller diameter than the distal portion (22). Both the proximal and distal portions (20 and 22) are tubular. The proximal portion (20) defines a proximal airflow channel. The proximal portion further includes an air outlet (24). The distal heater casing (18) includes a proximal portion (26) and a distal portion (28). The proximal portion (26) has a larger diameter than the distal portion (28). Both the proximal and distal portions (26 and 28) are tubular. The distal portion (28) defines a distal airflow channel. The distal portion (28) includes a distal air inlet (30).

The heater assembly (10) additionally includes a heater mounting portion (32). The heater mounting portion (32) includes a proximal portion (34) and a distal portion (36). The proximal portion (34) has a larger diameter than the distal portion (36). Both the proximal and distal portions (34 and 36) are tubular.

The proximal and distal heater casings (16 and 18) and the heater mounting portion (32) are made of a plastic material, preferably polyether ether ketone (PEEK) due to its favorable mechanical and insulating properties.

The proximal portion (20), the tubular heating chamber (12), the heater mounting portion (32), and the distal portion (28) define an airflow channel including an airflow path (38). The proximal heater casing (16), the tubular heating chamber (12), the heater mounting portion (32), and the distal heater casing (18) are arranged coaxially around the longitudinal axis (40) of the heater assembly (10). The proximal heater casing (16), the tubular heating chamber (12), the heater mounting portion (32), and the distal heater casing (18) enclose a hollow air space. The hollow air space provides insulation for the tubular heating chamber (12). Accordingly, heat loss from the tubular heating chamber (12) and heat transfer to the exterior of the heater assembly are reduced.

The tubular heating chamber (12) has a wall surface made of a metal tube, preferably the tubular heating chamber is made of stainless steel. A flexible heating element (42) is wrapped around an outer surface of the tubular heating chamber (12) to heat the tubular heating chamber (12) and ultimately heat an aerosol-forming substrate (not shown) accommodated within the interior space of the tubular heating chamber (12). The heating element (42) includes an electrically conductive heating track (44) on an electrically insulating flexible substrate (46). The electrically conductive heating substrate (46) typically comprises a heat-resistant flexible polyimide film having electrically conductive heating tracks (44) forming a serpentine pattern on the film. The electrically conductive heating tracks (44) are connected to a power supply (not shown) and generate heat when current passes through them. In the illustrated embodiment, proximal and distal edge portions of the flexible substrate (46) are not covered by the heating tracks (44). In other embodiments, different areas or even the entire surface of the flexible substrate (46) may be covered by the heating track (44). Alternatively, the heating element (42) may be configured as an induction heating element comprising a susceptor and an induction coil (not shown).

The distal portion (22) of the proximal heater casing (16) includes a proximal wall surface (48). The proximal wall surface (48) includes a circular groove (50). The circular groove (50) includes a chamfered inner side wall surface (52). Accordingly, the circular groove (50) has a right trapezoidal cross section. A proximal flared end (54) of the tubular heating chamber (12) is mounted in the circular groove (50). The chamfered inner side wall surface (52) and the proximal flared end (54) have the same chamfer.

The proximal portion (26) of the distal heater casing (18) includes a distal wall surface (56) including a distal opening (58). The distal portion (36) of the heat mounting portion (32) is mounted within the distal opening (58). A seal (60) is arranged between the proximal portion (34) of the heater mounting portion (32) and the inner surface of the proximal portion (26) of the distal heater casing (18). Accordingly, the proximal portion (34) of the heater mounting portion (32) is spaced from the inner wall surface of the distal heater casing (18). Additionally, the seal (60) is spaced from the tubular heating chamber (12). The seal (60) is an O-ring made of ethylene propylene diene monomer (EPDM) rubber. The seal (60) has a Shore hardness of 70 A as determined by the technical standard ISO868 Type A. This hardness was found to be sufficiently soft to absorb manufacturing tolerances, yet sufficiently hard to apply force to the heater assembly (10) to provide a seal of the airflow path (38) and integrity of the heater assembly (10). The seal (60) has an uncompressed thickness or diameter of 1 mm. This thickness was also found to be suitable for absorbing manufacturing tolerances and applying force to the heater assembly (10) to provide a seal of the airflow path (38) and integrity of the heater assembly (10).

The heater mounting portion (32) includes a circular groove (62) having a chamfered inner side wall surface (64). Accordingly, the circular groove (62) has a right trapezoidal cross section. A distal flared end (66) of a tubular heating chamber (12) is mounted in the circular groove (62).

The flared ends (54 and 66) of the tubular heating chamber (12) are press-fitted into the circular grooves (50 and 62), respectively. The flared ends (54 and 66) are not surrounded by the heating element (42).

Figures 2a and 2b illustrate cross-sectional views of a chamfered side wall surface (68) having a flared end (70). The chamfered side wall surface (68) can be one or both of the chamfered inner side wall surfaces (52 and 64). The flared end (70) can be one or both of the flared ends (54 and 66). The chamfered side wall surface (68) and the flared end (70) have a length (72) measured along the chamfer, a transverse length (74) measured perpendicular to the longitudinal axis (40), and an axial length (76) measured along the longitudinal axis (40). The axial length of the chamfered inner side wall surfaces (52 and 64) is from 0.8 mm to 4 mm and the transverse length is from 0.5 mm to 2.5 mm. The axial length of the flared ends (54 and 66) is 0.8 mm to 4 mm and the transverse length is 0.5 mm to 2.5 mm.

The chamfered side wall surface (68) is chamfered at a chamfer angle (78). The flared end (70) is chamfered at a chamfer angle (80). The chamfer angles (78 and 80) are measured with respect to the longitudinal axis (40) of the heater assembly (10). The chamfered side wall surface (68) and the flared end (70) are parallel. Accordingly, the chamfer angles (78 and 80) have the same absolute value. The chamfer angle (78) is in the range of 20° to 45°, preferably in the range of 25° to 40°, more preferably in the range of about 30°. The chamfer angle (80) is in the range of 20° to 45°, preferably in the range of 25° to 40°, more preferably in the range of about 30°. Both chamfer angles (78 and 80) are between 20° and 45°, preferably between 25° and 40°, more preferably about 30°. These chamfer angle ranges, particularly a chamfer angle of 30°, provide improved impact resistance as the impact initial force along the longitudinal axis of the heater assembly (10) is split into two perpendicularly smaller forces.

FIG. 2c shows how the initial force along the longitudinal axis F is split into forces F1 (along the chamfer) and F2 (perpendicular to the chamfer). For example, for a chamfer angle of 30°, F1 is about 87% (cos30°) of the initial force F. However, this force F1 is limited because the tubular heating chamber (12) cannot move along its flared end without expanding it. The second force F2 is about 50% (sin30°) of the initial force F. F2 pushes the chamfered inner side walls (52 and 64) toward the tubular hollow core. However, the conical structure has already reduced F2 to a sustainable force that the elastic properties of the plastic part can maintain when the magnitude of F is in the range of the drop test force.

FIG. 2d shows a cross-sectional view of a chamfered side wall surface (82). The chamfered side wall surface (82) can be one or both of the chamfered inner side wall surfaces (52 and 64). The chamfered side wall surface (82) includes three ribs (84). The ribs (84) press against the surface of the flared end.

FIG. 3 shows a cross-sectional view of an aerosol generating device (86). The aerosol generating device (86) includes the heater assembly (10) of FIG. 1. The aerosol generating device (86) may additionally include a power supply (88) and control electronics (90). The power supply (88) may be a rechargeable battery. At the opening (92), an aerosol forming substrate (not shown) may be at least partially inserted into the tubular heating chamber (12) of the heater assembly (10).

Claims (15)

As a heater assembly for an aerosol generating device,
A tubular heating chamber for heating an aerosol forming substrate, said tubular heating chamber comprising a proximal flared end; and
A heater assembly comprising a heater casing arranged around the heating chamber, the heater casing including a proximal wall surface, the proximal wall surface including a circular groove extending proximally from an inner surface of the proximal wall surface, the circular groove including a chamfered inner side wall surface, the chamfered inner side wall surface and the proximal flared end of the tubular heating chamber having a matching shape, the proximal flared end of the tubular heating chamber being mounted within the circular groove of the proximal wall surface. A heater assembly in the first paragraph, wherein the chamfered inner side wall surface of the heater casing flares out in the proximal direction. A heater assembly according to claim 1 or 2, wherein the tubular heating chamber comprises a distal flared end, and preferably, the heater assembly further comprises a heater mounting portion, wherein the distal flared end of the tubular heating chamber is mounted within the heater mounting portion. In the third aspect, the heater assembly further comprises the heater mounting portion, the distal flared end of the tubular heating chamber being mounted within the heater mounting portion, the heater mounting portion comprising an additional circular groove extending distally from an inner proximal surface of the heater mounting portion at the proximal end, the circular groove comprising a chamfered inner side wall surface, the chamfered inner side wall surface flaring distally, the chamfered inner side wall surface and the distal flared end of the tubular heating chamber having a matching shape, the distal flared end of the tubular heating chamber being mounted within the circular groove of the heater mounting portion. A heater assembly according to any one of claims 1 to 4, wherein one or both of the chamfered inner side wall surface of the proximal wall surface and the chamfered inner side wall surface of the heater mounting portion comprise at least one rib, preferably three ribs. A heater assembly according to any one of claims 1 to 5, wherein the chamfered inner side wall surface of the heater casing has the same chamfer angle as the proximal flared end of the tubular heating chamber. A heater assembly in claim 6, wherein the proximal flared end of the tubular heating chamber and the chamfered inner side wall surface of the heater casing have a chamfer angle of 20° to 45°, preferably 25° to 40°, more preferably about 30°. A heater assembly according to any one of claims 1 to 7, wherein the length of the proximal flared end of the tubular heating chamber and the chamfered inner side wall surface of the heater casing is 0.5 to 5 mm, preferably 0.5 to 3 mm, more preferably 0.5 to 2 mm, and most preferably about 1 mm. A heater assembly according to any one of claims 1 to 8, wherein the heater casing includes a proximal heater casing and a distal heater casing, and the proximal heater casing includes a proximal wall surface having the circular groove. A heater assembly in claim 9, wherein the tubular heating chamber comprises a distal flared end, the heater assembly further comprises a heater mounting portion, the distal flared end of the tubular heating chamber is mounted within the heater mounting portion, the distal heater casing comprises the heater mounting portion, or the heater mounting portion is mounted within a distal opening of the distal heater casing. A heater assembly in claim 10, wherein the tubular heating chamber is fitted or pressure-fitted between the proximal heater casing and the heater mounting portion. A heater assembly in claim 10 or 11, wherein the heater mounting portion is mounted within the distal opening of the distal heater casing, and a sealing portion is arranged between the heater mounting portion and the inner surface of the distal heater casing. A heater assembly in claim 12, wherein one or both of the chamfered inner side wall surface of the proximal wall surface and the chamfered inner side wall surface of the heater mounting portion comprise at least one rib, preferably three ribs, and wherein the proximal heater casing, the distal heater casing, the tubular heating chamber, the heater mounting portion and the seal surround an air space, preferably the air space is an airtight space, more preferably the airtight space is hollow. An aerosol generating device comprising a heater assembly according to any one of claims 1 to 13. An aerosol-generating system comprising an aerosol-generating article comprising an aerosol-generating device according to claim 14 and a substrate portion comprising an aerosol-forming substrate, wherein the aerosol-generating article is configured to be at least partially inserted into the tubular heating chamber.