Aerosol generator equipped with an inductor coil

Abstract

An aerosol generator (10) is provided, comprising an inductor coil (24) which includes a first tubular portion of a conductive material, a second tubular portion of a conductive material, and a helical coil of a conductive material. The helical coil of the conductive material extends between the first tubular portion of the conductive material and the second tubular portion of the conductive material. The aerosol generator (10) also comprises a chamber (16) for receiving at least a portion of an aerosol generating article (102). The inductor coil (24) is arranged such that when the aerosol generating article (102) is inserted into the chamber (16), at least a portion of the aerosol generating article (102) is received within the inductor coil (24) and the inductor coil (24) is in direct contact with the aerosol generating article (102). The aerosol generator (10) also includes a power supply (42) and a control circuit (40) connected to an inductor coil (24) and configured to supply alternating current to the inductor coil (24) so ​​that the inductor coil (24) generates an alternating magnetic field when in use.

Description

Technical Field

[0001] The present disclosure relates to an aerosol generating device comprising an inductor coil. The present invention also relates to a method for forming an inductor coil for an aerosol generating device.

Background Art

[0002] It is known to generate an aerosol from an aerosol forming substrate of an aerosol generating article by applying heat to the substrate without combustion or burning of the substrate. The aerosol generating article may be cylindrical such as a cigarette, and the aerosol forming substrate may contain tobacco material. It is known to apply heat to such an aerosol generating article and heat the aerosol forming substrate of the article using a heat source external to the aerosol generating article.

[0003] However, external heat sources tend to heat the aerosol forming substrate non-uniformly. The aerosol forming substrate closest to the heat source is at the center of the aerosol generating article and is heated more than the aerosol forming substrate further away from the heat source.

[0004] It is also known to heat the aerosol forming substrate of such articles using a heat source located inside the aerosol forming substrate. In some aerosol generating systems, the internal heat source is inductively heated using an induction coil located outside the aerosol generating article and a susceptor material located within the central region of the aerosol generating article. Heating the aerosol forming substrate internally avoids the heat that has to cross through the wrapper to reach the aerosol forming substrate. However, heating the aerosol forming substrate internally also has heating of the substrate at the internal heat source or closest to the internal heat source and greatest, and decreasing as the distance from the internal heat source into the substrate increases, resulting in the aerosol forming substrate being heated in a non-uniform manner.

[0005] Uneven heating of an aerosol-forming substrate can mean that not all available volatile materials are released from the aerosol-forming substrate. This is because increasing the level of heat applied to the substrate to completely extract volatile materials from it, whether using external or internal heating, can lead to unintended and undesirable combustion of the substrate near the heat source, which can result in the generation of undesirable compounds and flavors.

[0006] Therefore, it is desirable to provide an aerosol generator that facilitates efficient and uniform heating of an aerosol-forming substrate without requiring a complex heating arrangement. [Overview of the Initiative]

[0007] According to a first aspect of the present disclosure, a method is provided for forming an inductor coil for an aerosol generator, the method comprising providing a tube of conductive material and cutting out a helical opening in at least a portion of the tube of conductive material. The helical opening defines a helical coil of conductive material, which forms an inductor coil of the aerosol generator. In other words, the helical coil of conductive material can form multiple windings of the inductor coil.

[0008] As used herein, the term “aerosol generator” is used to describe a device that interacts with an aerosol-forming substrate to generate an aerosol. Preferably, the aerosol generator is a smoking device that interacts with an aerosol-forming substrate to generate an aerosol that can be directly inhaled into the user’s lungs through the user’s mouth.

[0009] In this specification, the term "conductive" means at least 0.8 × 10⁻⁶ 6 The term "electrical insulation" is used to refer to materials having an electrical conductivity of siemens per meter. In this specification, the term "electrical insulation" refers to materials with an electrical conductivity of 0.8 × 10⁻⁶. 4It is used to refer to materials with an electrical conductivity of less than Siemens per meter.

[0010] Advantageously, by forming the inductor coil from a conductive material tube, it is possible to provide an inductor coil with a relatively smooth inner surface compared to conventional inductor coils formed by twisting a round wire into a helical coil shape. Advantageously, an inductor coil with a relatively smooth inner surface facilitates the direct insertion of an aerosol-generating article into the inductor coil.

[0011] The inventors have recognized that when alternating current flows through an inductor coil during use, the inductor coil may exhibit thermal losses in the form of resistive heating of the inductor coil. Advantageously, the relatively smooth inner surface of the inductor coil can increase or maximize the surface area of ​​the inductor coil that is in direct contact with the aerosol-generating article compared to conventional wound inductor coils. Advantageously, increasing or maximizing the surface area of ​​the inductor coil that is in direct contact with the aerosol-generating article can increase or maximize the transfer of heat generated by resistive heating from the inductor coil to the aerosol-forming substrate of the aerosol-generating article.

[0012] The process of cutting the helical opening may include any suitable cutting process. The cutting process may include cutting the helical opening using at least one of a mechanical cutting process, electrostatic discharge machining, and a laser cutter. The cutting process may include cutting the helical opening using a milling machine. Preferably, the cutting process includes cutting the helical opening using a laser cutter.

[0013] The process of cutting a spiral opening may include rotating and advancing a tube of conductive material relative to a fixed cutting device. Advantageously, moving the tube of conductive material relative to a fixed cutting device simplifies the cutting process compared to embodiments in which the cutting device is moved relative to the tube of conductive material.

[0014] The step of providing a conductive material tube may include positioning the conductive material tube on a mandrel. In embodiments in which the step of cutting a helical opening includes rotating and advancing the conductive material tube relative to a fixed cutting device, rotating and advancing the conductive material tube may simultaneously include rotating the conductive material tube relative to the mandrel and advancing the conductive material tube along the mandrel. Alternatively, rotating and advancing the conductive material tube may include fixing the conductive material tube to the mandrel and rotating and advancing the mandrel relative to the fixed cutting device.

[0015] The cutting process involves cutting a helical opening in only a portion of the conductive material tube to define a first end portion of the tube, a second end portion of the tube, and a central portion of the tube extending between the first and second end portions, wherein the helical opening extends only along the central portion of the tube. In this case, the inductor coil includes the first end portion of the tube, the second end portion of the tube, and a helical coil of conductive material extending between the first and second end portions of the tube.

[0016] Advantageously, at least one of the first end portion of the tube and the second end portion of the tube can facilitate the attachment of the inductor coil to the aerosol generator.

[0017] Preferably, the first end portion of the tube, the second end portion of the tube, and each winding of the helical coil have a maximum width extending in a direction parallel to the longitudinal axis of the tube, and the maximum width of the first end portion of the tube and the second end portion of the tube are greater than the maximum width of each winding of the helical coil.

[0018] The cutting step may further include cutting a plurality of individual openings in the tube of conductive material. In embodiments in which the cutting step defines a first end portion and a second end portion of the tube, the cutting step may include cutting a plurality of individual openings in at least one of the first end portion and the second end portion of the tube of conductive material.

[0019] Advantageously, multiple individual openings can facilitate the control of the airflow through an aerosol generator equipped with an inductor coil. For example, at least one of the individual openings can form an airflow opening.

[0020] Advantageously, multiple individual openings can reduce the weight of the inductor coil. Advantageously, multiple individual openings can reduce heat loss that could otherwise occur due to heat conduction from the helical coil of conductive material to the first and second end portions of the tube.

[0021] Preferably, the step of cutting a plurality of individual openings includes cutting a plurality of individual openings in both the first end portion of the conductive material tube and the second end portion of the conductive material tube.

[0022] The process of cutting multiple individual openings may include cutting multiple individual openings using at least one of a mechanical cutting process, electrostatic discharge machining, and a laser cutter. Preferably, the process of cutting multiple individual openings includes cutting multiple individual openings using a laser cutter. Preferably, the process of cutting multiple individual openings includes the same cutting technique as the process of cutting a helical opening.

[0023] The process of cutting multiple individual openings may be performed before, after, or simultaneously with the process of cutting the spiral opening.

[0024] Preferably, the individual openings are distributed symmetrically in the circumferential direction extending around the longitudinal axis of the conductive material tube. The individual openings can be arranged in a row or more rows extending in the circumferential direction.

[0025] Each individual opening may have any suitable shape. Each individual opening may be circular, triangular, rectangular, pentagonal, hexagonal, heptagonal, or octagonal.

[0026] The method may include the step of providing an electrically insulating material layer on the surface of a tube of a conductive material. Advantageously, the electrically insulating material may electrically insulate an inductor coil from other components of the aerosol generating device and from an aerosol generating article inserted into the inductor coil. Advantageously, the electrically insulating material may prevent an electrical short circuit between adjacent windings of the inductor coil. Advantageously, the electrically insulating material may mechanically stabilize the inductor coil. For example, the electrically insulating material may reduce or eliminate the spring-like behavior of the helical coil of the conductive material forming the inductor coil.

[0027] The layer of electrically insulating material may extend over at least a portion of the outer surface of the tube of conductive material. The layer of electrically insulating material may extend over at least a portion of the inner surface of the tube of conductive material. The layer of electrically insulating material may extend over at least a portion of each of the outer and inner surfaces of the tube of conductive material. The layer of electrically insulating material may extend substantially over the entire tube of conductive material.

[0028] The step of providing the layer of electrically insulating material includes wrapping a strip of electrically insulating material around the outer surface of the tube of conductive material. The wrapping step may include helically wrapping a strip of electrically insulating material around the outer surface of the tube of conductive material. Preferably, the helical strip of electrically insulating material is wrapped around the outer surface of the tube of conductive material in a first direction, and the helical opening extends around the tube of conductive material in a second direction, the second direction being opposite to the first direction.

[0029] The strip of electrically insulating material may include a polyimide film such as Kapton.

[0030] The step of providing the layer of electrically insulating material may include overmolding at least a portion of the tube of conductive material with the electrically insulating material.

[0031] The electrically insulating material may include at least one of a polymer, a ceramic, and a glass. The electrically insulating material may include parylene.

[0032] A tube made of conductive material may have an inner surface, and this method includes shaping at least one edge of a winding of a helical coil made of conductive material on the inner surface of the tube made of conductive material. Advantageously, shaping at least one edge of a winding of a helical coil made of conductive material can facilitate the insertion of an aerosol-generating article into the inductor coil.

[0033] The molding process may include providing a bevel, chamfer, or fillet on at least one edge of the winding of the helical coil of conductive material.

[0034] The molding process may be carried out using any suitable process. The molding process may include at least one of cutting and / or machining at least one edge of the windings of the helical coil of conductive material. The molding process may include a grinding process.

[0035] The molding process may include molding only one edge of the windings of a helical coil of conductive material. Advantageously, molding only one edge facilitates the insertion of the aerosol-generating article into the inductor coil and facilitates the retention of the aerosol-generating article within the inductor coil. The shapeless edges of each winding can resist the removal of the aerosol-generating article from the inductor coil until the aerosol-generating article shrinks during use of the aerosol-generating system.

[0036] The method may include repeating the step of cutting at least along the length of a tube of conductive material to form a plurality of connected inductor coils along the tube of conductive material. The method includes repeating any combination of the steps described herein to form a plurality of connected inductor coils along the tube of conductive material. Preferably, the method further includes cutting the tube of conductive material between a series of connected inductor coils to form a plurality of individual inductor coils.

[0037] The helical opening may have a number average width of at least 0.5 mm, or at least 1 mm, or at least 1.5 mm, or at least 2 mm. The helical opening may have a number average width of less than 5 mm, or less than 4 mm, or less than 3 mm, or less than 2 mm.

[0038] The tube can be formed from any suitable conductive material. Preferably, the tube is formed from a metal or metal alloy. The tube can be formed from at least one of copper, copper alloys, copper-nickel alloys, tungsten, aluminum, aluminum alloys, and steel. Suitable steels include stainless steel such as 316 stainless steel.

[0039] According to a second aspect of this disclosure, an inductor coil is provided which is formed using the method according to the first aspect of this disclosure, in accordance with any of the embodiments described herein.

[0040] According to a third aspect of the present disclosure, an inductor coil for an aerosol generator is provided, the inductor coil comprising a first tubular portion of a conductive material, a second tubular portion of a conductive material, and a helical coil of a conductive material extending between the first tubular portion of the conductive material and the second tubular portion of the conductive material.

[0041] The inductor coils according to the second and third embodiments of this disclosure may be fitted with the following optional and preferred features:

[0042] Preferably, the helical coil is formed integrally with the first tubular portion and the second tubular portion.

[0043] Preferably, each of the first tubular portion, the second tubular portion, and each winding of the helical coil has a maximum width extending in a direction parallel to the longitudinal axis of the inductor coil, and the maximum width of each of the first tubular portion and the second tubular portion is greater than the maximum width of each winding of the helical coil.

[0044] The inductor coil may further include a plurality of individual openings provided in at least one of a first tubular portion of the conductive material and a second tubular portion of the conductive material.

[0045] Advantageously, multiple individual openings can facilitate the control of the airflow through an aerosol generator equipped with an inductor coil. For example, at least one of the individual openings can form an airflow opening.

[0046] Advantageously, multiple individual openings can reduce the weight of the inductor coil. Advantageously, multiple individual openings can reduce heat loss that could otherwise occur due to heat conduction from the helical coil of conductive material to the first and second end portions of the tube.

[0047] The inductor coil may include a plurality of separate openings provided in both the first tubular portion of the conductive material and the second tubular portion of the conductive material.

[0048] Preferably, the individual openings are distributed symmetrically in the circumferential direction extending around the longitudinal axis of the conductive material tube. The individual openings can be arranged in a row or more rows extending in the circumferential direction.

[0049] Each individual opening may have any suitable shape. Each individual opening may be circular, triangular, rectangular, pentagonal, hexagonal, heptagonal, or octagonal.

[0050] The inductor coil may include a layer of electrical insulating material extending over at least one surface of the first tubular portion, the second tubular portion, and the helical coil.

[0051] Advantageously, the electrical insulating material can electrically insulate the inductor coil from other components of the aerosol generator and the aerosol generating article inserted into the inductor coil. Advantageously, the electrical insulating material can prevent electrical short circuits between adjacent windings of the inductor coil. Advantageously, the electrical insulating material can mechanically stabilize the inductor coil. For example, the electrical insulating material can reduce or eliminate the spring-like behavior of the helical coil of the conductive material forming the inductor coil.

[0052] The electrical insulating material layer may extend over the surfaces of the first tubular portion, the second tubular portion, and the helical coil. The electrical insulating material layer may extend over the outer surfaces of the first tubular portion, the second tubular portion, and the helical coil. The electrical insulating material layer may extend over the inner surfaces of the first tubular portion, the second tubular portion, and the helical coil. The electrical insulating material layer may extend substantially over the entire first tubular portion, the entire second tubular portion, and the entire helical coil.

[0053] The electrical insulating material layer may include fragments of electrical insulating material wound around the outer surfaces of the first tubular portion, the second tubular portion, and the helical coil. The fragments of electrical insulating material can be wound helically around the outer surfaces of the first tubular portion, the second tubular portion, and the helical coil. Preferably, the helical fragments of electrical insulating material are wound around the outer surfaces of the first tubular portion, the second tubular portion, and the helical coil in a first direction, and the helical coil is rotated in a second direction, the second direction being opposite to the first direction.

[0054] The electrical insulating material fragments may include polyimide films such as Kapton.

[0055] An electrical insulating material layer can be overmolded onto the first tubular portion, the second tubular portion, and at least a portion of the helical coil.

[0056] The electrical insulating material may include at least one of polymers, ceramics, and glass. The electrical insulating material may also include parylene.

[0057] Preferably, the helical coil of the conductive material has an inner surface, and at least one edge of the windings of the helical coil includes a bevel, chamfer, or fillet. Advantageously, providing at least one edge of the windings of the helical coil with a bevel, chamfer, or fillet can facilitate the insertion of an aerosol-generating article into the inductor coil. Preferably, only one edge of each winding includes a bevel, chamfer, or fillet. Advantageously, providing only one edge of each winding with a bevel, chamfer, or fillet can facilitate the insertion of an aerosol-generating article into the inductor coil and facilitate the retention of the aerosol-generating article within the inductor coil. Edges of each winding without a bevel, chamfer, or fillet may resist the removal of the aerosol-generating article from the inductor coil until the aerosol-generating article shrinks during use of the aerosol-generating system.

[0058] A helical coil may define a helical opening extending between the windings of the helical coil. The helical opening may have a number average width of at least 0.5 mm, or at least 1 mm, or at least 1.5 mm, or at least 2 mm. The helical opening may have a number average width of less than 5 mm, or less than 4 mm, or less than 3 mm, or less than 2 mm.

[0059] The first tubular portion, the second tubular portion, and the helical coil can be formed from any suitable conductive material. Preferably, the conductive material is a metal or a metal alloy. The conductive material may be at least one of copper, copper alloys, copper-nickel alloys, tungsten, aluminum, aluminum alloys, or steel. Suitable steels include stainless steel such as 316 stainless steel.

[0060] A fourth aspect of the present disclosure provides an aerosol generator comprising an inductor coil according to a second or third aspect of the present disclosure, as described in any of the embodiments described herein. The aerosol generator also includes a chamber for receiving at least a portion of the aerosol generating article. The aerosol generator also includes a power supply and control circuit connected to the inductor coil and configured to supply an alternating current to the inductor coil so that the inductor coil generates an alternating magnetic field when in use.

[0061] Preferably, the inductor coil is positioned within the chamber such that the aerosol-generating article inserted into the chamber is received within the inductor coil.

[0062] Advantageously, positioning the inductor coil within the chamber facilitates the transfer of heat generated by resistive heating from the inductor coil to the aerosol-forming substrate of the aerosol-generating article received within the chamber. In embodiments where the inductor coil is used to inductively heat a susceptor material or element positioned inside the aerosol-forming substrate, advantageously, the inductive heating of the susceptor element and the resistive heating of the inductor coil may provide simultaneous internal and external heating of the aerosol-forming substrate. Advantageously, simultaneous internal and external heating of the aerosol-forming substrate may facilitate more uniform heating of the aerosol-forming substrate.

[0063] The inductor coil is suspended inside the chamber.

[0064] As used herein, the term “suspended” refers to an arrangement in which less than 50% of the outer surface of the inductor coil is in contact with the inner surface of the chamber. Advantageously, suspending the inductor coil within the chamber may reduce or minimize the transfer of heat generated by resistive heating from the inductor coil to other components of the aerosol generator. Advantageously, by reducing or minimizing the transfer of heat generated by resistive heating from the inductor coil to other components of the aerosol generator, the transfer of heat generated by resistive heating from the inductor coil to the aerosol-forming substrate may be increased or maximized.

[0065] Preferably, less than 40 percent of the outer surface of the inductor coil is in contact with the inner surface of the chamber. Preferably, less than 30 percent of the outer surface of the inductor coil is in contact with the inner surface of the chamber. Preferably, less than 20 percent of the outer surface of the inductor coil is in contact with the inner surface of the chamber. Preferably, less than 10 percent of the outer surface of the inductor coil is in contact with the inner surface of the chamber. Preferably, less than 5 percent of the outer surface of the inductor coil is in contact with the inner surface of the chamber.

[0066] Preferably, the chamber comprises a first open end through which at least a portion of an aerosol-generating article may be inserted into the chamber, and a second closed end opposite the first open end.

[0067] The chamber may include a substantially cylindrical inner surface. Preferably, the outer surface of the inductor coil is spaced apart from the cylindrical inner surface of the chamber. Advantageously, the space between the outer surface of the inductor coil and the cylindrical inner surface of the chamber reduces or minimizes conductive heat transfer from the inductor coil to other components of the aerosol generator.

[0068] Preferably, the aerosol generator further comprises an airflow channel defined between the inner cylindrical surface of the chamber and the outer surface of the inductor coil, the airflow channel providing fluid communication between a first end of the chamber and a second end of the chamber.

[0069] Advantageously, by using the space between the cylindrical inner surface of the chamber and the outer surface of the inductor coil as an airflow channel, it may be possible to eliminate the need for a complex airflow arrangement within the chamber. For example, the cylindrical inner surface of the chamber may have a substantially smooth and continuous surface.

[0070] Advantageously, by using the space between the cylindrical inner surface of the chamber and the outer surface of the inductor coil as an airflow channel, heat transfer from the inductor coil to other components of the aerosol generator can be further reduced or minimized. Advantageously, heat loss from the outer surface of the inductor coil can be absorbed by the airflow through the airflow channel, and the heated airflow can be absorbed by the aerosol-forming substrate received within the chamber.

[0071] Preferably, the annular gap has a radial number average width of at least 0.5 mm, or at least 1 mm, or at least 1.5 mm, or at least 2 mm. Preferably, the annular gap has a radial number average width of less than 5 mm, or less than 4 mm, or less than 3 mm, or less than 2 mm.

[0072] Preferably, the aerosol generator comprises a pressure sensor in fluid communication with an airflow channel defined by an annular gap. Advantageously, the relatively narrow airflow channel defined by the annular gap can amplify the pressure drop that occurs when a user inhales the aerosol generating system, including the aerosol generator. Advantageously, the amplified pressure drop can increase the sensitivity of the pressure sensor to user inhalation.

[0073] Preferably, the pressure sensor is configured to provide a signal to the control circuit indicating that a user has inhaled into an aerosol generating system, including an aerosol generator.

[0074] Preferably, the aerosol generator includes at least one projection extending into the chamber from a closed second end of the chamber. Advantageously, at least one projection may abut the upstream end of an aerosol generating article received in the chamber, separating the upstream end of the aerosol generating article from the closed end of the chamber. Advantageously, separating the upstream end of the aerosol generating article from the closed end of the chamber may facilitate airflow into the aerosol generating article during use.

[0075] The aerosol generator may include a housing, and the inductor coil, power supply, and control circuit are located within the housing. Preferably, the housing has an end wall defining a closed second end of the chamber, with at least one projection extending from the end wall into the chamber. Preferably, at least one projection is formed integrally with the end wall.

[0076] Preferably, at least one projection comprises at least three projections. Advantageously, providing at least three projections may facilitate the secure and correct positioning of the aerosol-generating article within the chamber. Preferably, the chamber has a longitudinal axis defining a first direction along which at least a portion of the aerosol-generating article may be inserted into the chamber, and the at least three projections are equidistant from each other in the circumferential direction around the longitudinal axis.

[0077] The aerosol generator may include a susceptor element. Advantageously, providing the susceptor element as part of the aerosol generator may eliminate the need to provide a susceptor element for each aerosol generating article. Advantageously, this may reduce the cost of each aerosol generating article.

[0078] As used herein, the term “susceptor element” refers to an element containing a material capable of converting magnetic field energy into heat. When a susceptor element is located in an alternating magnetic field, the susceptor is inductively heated. The heating of the susceptor may be the result of at least one of hysteresis losses and eddy currents induced within the susceptor, depending on the electrical and magnetic properties of the susceptor material.

[0079] Preferably, the susceptor element is an elongated susceptor element. Preferably, the elongated susceptor element extends into the chamber from the closed second end of the chamber. Preferably, at least a portion of the elongated susceptor element is positioned inside the inductor coil.

[0080] The susceptor element may be formed from any material that can be inductively heated to a temperature sufficient to aerosolize the aerosol-forming substrate. Suitable materials for the susceptor element include graphite, molybdenum, silicon carbide, stainless steel, niobium, and aluminum. Preferred susceptor elements contain metal or carbon. Preferably, the susceptor element contains or consists of ferromagnetic materials, such as ferrite iron, ferromagnetic steel, or stainless steel ferromagnetic alloys, ferromagnetic particles, and ferrite. Suitable susceptor elements may be aluminum or contain aluminum. The susceptor element preferably contains more than about 5 percent, preferably more than about 20 percent, more preferably more than about 50 percent or more than 90 percent of ferromagnetic or paramagnetic material. Preferred susceptor elements may be heated to a temperature above about 250 degrees Celsius.

[0081] The susceptor element may comprise a nonmetallic core having a metal layer disposed on top of the nonmetallic core. For example, the susceptor element may include one or more metal tracks formed on the outer surface of a ceramic core or substrate.

[0082] The susceptor element may have a protective outer layer, such as a protective ceramic layer or a protective glass layer. The protective outer layer may encase the susceptor element. The susceptor element may have a protective coating formed of glass, ceramic, or an inert metal on the outside of the core of the susceptor material.

[0083] The susceptor element may have any suitable cross-section. For example, the susceptor element may have a square, oval, rectangular, triangular, pentagonal, hexagonal, or similar cross-sectional shape. The susceptor element may have a planar or flat cross-sectional shape.

[0084] The susceptor element may be solid, hollow, or porous. Preferably, the susceptor element is solid.

[0085] In embodiments where the susceptor element has a planar or flat cross-sectional shape, the susceptor element preferably has a thickness of about 1 mm to about 8 mm, more preferably about 3 mm to about 5 mm. The thickness of the susceptor element is measured along the long axis of the aerosol generator. Preferably, the susceptor element has a width or diameter of about 3 mm to about 12 mm, more preferably about 4 mm to about 10 mm, and more preferably about 5 mm to about 8 mm. The width or diameter of the susceptor element is perpendicular to its thickness.

[0086] In embodiments where the susceptor element is an elongated susceptor element, the elongated susceptor element is preferably in the form of a pin, rod, blade, or plate. Preferably, the elongated susceptor element has a length of about 5 mm to about 15 mm, for example, about 6 mm to about 12 mm, or about 8 mm to about 10 mm. Preferably, the elongated susceptor element has a width of about 1 mm to about 8 mm, more preferably about 3 mm to about 5 mm. The elongated susceptor element may have a thickness of about 0.01 mm to about 2 mm. If the elongated susceptor element has a certain cross-section, for example a circular cross-section, it preferably has a width or diameter of 1 mm to 5 mm.

[0087] Preferably, the inductor coil is positioned such that at least a portion of the aerosol-generating article is received within the inductor coil when the aerosol-generating article is inserted into the chamber. Preferably, the inductor coil is positioned such that it is in direct contact with the aerosol-generating article when the aerosol-generating article is inserted into the chamber. Advantageously, direct contact between the inductor coil and the aerosol-generating article facilitates the conduction of heat generated by resistive heating from the inductor coil to the aerosol-generating article.

[0088] The power supply may be a DC power supply. In one embodiment, the power supply is a DC power supply having a DC supply voltage in the range of approximately 2.5 volts to approximately 4.5 volts and a DC supply current in the range of approximately 1 ampere to approximately 10 amperes (corresponding to a DC power supply in the range of approximately 2.5 watts to approximately 45 watts).

[0089] The power supply may be configured to operate at high frequencies. As used herein, the term “high-frequency oscillating current” means an oscillating current having a frequency of about 500 kilohertz to about 30 megahertz. The high-frequency oscillating current may have a frequency of about 1 megahertz to about 30 megahertz, preferably about 1 megahertz to about 10 megahertz, and more preferably about 5 megahertz to about 8 megahertz.

[0090] The aerosol generator comprises a control circuit connected to an inductor coil and a power supply. The control circuit is configured to control the power supply from the power supply to the inductor coil. The control circuit may include a microprocessor, which may be a programmable microprocessor, a microcontroller, an application-specific integrated circuit chip (ASIC), or other electronic circuit capable of providing control. The control circuit may include further electronic components. The control circuit may be configured to regulate the supply of current to the inductor coil. The current may be supplied to the inductor coil continuously after the aerosol generator is started, or intermittently, such as with each smoke extraction. The control circuit may advantageously include a DC / AC inverter, which may include a Class D or Class E power amplifier.

[0091] The control circuit may be configured to supply electrical energy from the power source to the inductor coil as alternating current, thereby enabling the inductor coil to generate heat through one or a combination of i) resistive heating of the inductor coil and ii) heating of the susceptor element through inductive coupling with the susceptor of the inductor coil. The control circuit may be configured to adjust at least one parameter of the alternating current to change the inductive coupling with the susceptor element of the inductor coil, thereby adjusting the balance between the heat generated through resistive heating of the inductor coil and the heat generated through inductive coupling with the susceptor element of the inductor coil.

[0092] As used herein, the term “inductive coupling” refers to the heating of a susceptor element when it is penetrated by an alternating magnetic field. Heating is caused by the generation of eddy currents in the susceptor element. Heating can also be caused by magnetic hysteresis losses.

[0093] Preferably, at least one parameter includes the frequency of the alternating current. The inductive coupling between the inductor coil and the susceptor element changes with the frequency of the alternating current. The frequency is a value f associated with the alternating current that provides optimal coupling with the susceptor element, enabling nearly the entire energy transfer from the inductor coil to the susceptor element, and consequently creating an alternating magnetic field that yields most of the heat generated by the inductive heating of the susceptor element. suceptor The frequency may be adjusted to have a frequency of f. The frequency is a value associated with an alternating current that provides little or no coupling with the susceptor element and allows the transfer of almost all of the energy remaining in the inductor coil, resulting in an alternating magnetic field that produces most of the heat generated by the resistive heating of the inductor coil. inductor coil The frequency may also be adjusted to have a value f associated with the alternating current, which results in a combination of inductive heating of the susceptor element and resistive heating of the inductor coil. total These frequencies may be adjusted to have the following characteristics. Each of these frequencies varies depending on the materials, physical properties, and configuration of the inductor coil and susceptor element, such as the inductance of the inductor coil and the permeability of the material from which the susceptor element is formed.

[0094] The control circuit may be configured to supply an alternating current to the inductor coil, causing it to generate an alternating magnetic field that inductively heats the susceptor element of the aerosol-generating article, and to supply a direct current to the inductor coil to resistively heat the inductor coil, thereby conducting the aerosol-generating article. Advantageously, using a single coil to provide both heating power to the internal susceptor and resistive heating of the coil itself provides two different heat sources at different locations for an aerosol-forming substrate having a structure that is less complex than a typical induction heating arrangement.

[0095] The control circuit may be configured to adjust the amount of heating provided by induction heating by adjusting the alternating current supplied to the inductor coil during the operation of the aerosol generator.

[0096] The control circuit may be configured to adjust the amount of heating provided by resistive heating by adjusting the DC current supplied to the inductor coil during the operation of the aerosol generator.

[0097] The control circuit may be configured to supply alternating current and direct current to the inductor coil at different times. For example, after the aerosol generator is started, the control circuit may be configured to initially supply alternating current to the inductor coil, and then to supply direct current to the inductor coil. This may provide rapid aerosol generation at the start of a usage session, but may also provide complete and efficient heating of the entire aerosol-forming substrate throughout the entire usage session. At the beginning of a usage session, the susceptor may be in closer contact with the aerosol-forming substrate, so inductive heating of the internal susceptor may provide aerosol more quickly than external resistance heating. The internal susceptor may also heat up more quickly than the external inductor coil if the susceptor has a lower thermal mass than the inductor coil.

[0098] The control circuit may be configured to supply alternating current and direct current to the inductor coil in an alternating sequence. Alternating external and internal heating may be beneficial to avoid overheating of any part of the aerosol-forming substrate.

[0099] The control circuit may be configured to simultaneously supply both alternating current and direct current to the inductor coil. In this way, a larger amount of thermal energy can be transferred to the aerosol-forming substrate, generating a larger volume of aerosol, without either the susceptor or the inductor coil reaching a temperature at which any part of the aerosol-generating article may burn.

[0100] An aerosol generator comprising a control circuit configured to change at least one parameter of the alternating current, or configured to supply both alternating and direct current to an inductor coil, can change the mode of heat application to the aerosol-forming substrate by any one of the following heating regimes: a) Through the resistive heating of the inductor coil only, or primarily through it, b) By heating the susceptor element solely through inductive coupling with the susceptor element of the inductor coil, or primarily through that, c) A combination of resistive heating of the inductor coil and heating of the susceptor element through inductive coupling between the inductor coil and the susceptor element.

[0101] Preferably, the aerosol generator is portable. The aerosol generator may be comparable in size to a conventional cigar or cigarette. The aerosol generator may have an overall length of approximately 30 mm to approximately 150 mm. The aerosol generator may have an outer diameter of approximately 5 mm to approximately 30 mm.

[0102] The aerosol generator housing may be elongated. The housing may be made of any suitable material or combination of materials. Examples of suitable materials include metals, alloys, plastics, or composite materials containing one or more of these materials, or thermoplastic resins suitable for food or pharmaceutical applications, such as polypropylene, polyetheretherketone (PEEK), and polyethylene. The material is preferably light and not brittle.

[0103] The housing may include a mouthpiece. The mouthpiece may include at least one air intake and at least one air outlet. The mouthpiece may include two or more air intakes. One or more of the air intakes may reduce the temperature of the aerosol and reduce the concentration of the aerosol before it is delivered to the user.

[0104] Alternatively, the mouthpiece may be provided as part of the aerosol-generating article.

[0105] As used herein, the term “mouthpiece” refers to a portion of an aerosol generator that is positioned in the user’s mouth to allow direct inhalation of aerosols generated by the aerosol generator from an aerosol generating article received within the housing’s chamber.

[0106] The aerosol generator may include a user interface for activating the device, such as a button to start heating the device, or a display that shows the status of the device or the aerosol-forming substrate.

[0107] According to a fifth aspect of this disclosure, an aerosol generating system is provided. The aerosol generating system comprises an aerosol generating device according to a fourth aspect of this disclosure, in accordance with any embodiment described herein. The aerosol generating system also comprises an aerosol generating article containing an aerosol-forming substrate.

[0108] As used herein, the term "aerosol-generating article" refers to an article comprising an aerosol-forming substrate having the ability to release volatile compounds capable of forming aerosols. Aerosol-generating articles may be disposable.

[0109] As used herein, the term "aerosol-forming substrate" refers to a substrate consisting of, or containing, an aerosol-forming material having the ability to release volatile compounds upon heating in order to generate aerosols.

[0110] The aerosol-generating article may include an article susceptor element. Preferably, the article susceptor element is positioned in direct contact with the aerosol-forming substrate. Preferably, the article susceptor element is an internal susceptor element positioned within the aerosol-forming substrate.

[0111] Preferably, the aerosol generating article is configured such that at least a portion of the article susceptor element is positioned within the inductor coil when the aerosol generating article is inserted into the chamber of the aerosol generating device.

[0112] The article susceptor element may have any of the optional or preferred features described above with respect to a susceptor element that forms part of an aerosol generator.

[0113] Preferably, the aerosol-forming substrate is a solid aerosol-forming substrate. However, the aerosol-forming substrate may contain both solid and liquid components. Alternatively, the aerosol-forming substrate may be a liquid aerosol-forming substrate.

[0114] The aerosol-forming substrate preferably contains nicotine. More preferably, the aerosol-forming substrate contains tobacco. Alternatively, or additionally, the aerosol-forming substrate may contain a non-tobacco-containing aerosol-forming material.

[0115] When the aerosol-forming substrate is a solid aerosol-forming substrate, the solid aerosol-forming substrate may contain one or more of the following: herb leaves, tobacco leaves, tobacco stems, puffed tobacco, and homogenized tobacco, for example, one or more of the following: powder, granules, pellets, fragments, twisted yarn, splinters, or sheets.

[0116] Optionally, the solid aerosol-forming substrate may contain tobacco or non-tobacco volatile flavor compounds, which are released upon heating of the solid aerosol-forming substrate. The solid aerosol-forming substrate may also contain, for example, one or more capsules containing additional tobacco or non-tobacco volatile flavor compounds, which may melt during heating of the solid aerosol-forming substrate.

[0117] Optionally, the solid aerosol-forming substrate may be provided on or embedded within a thermally stable carrier. The carrier may take the form of a powder, granules, pellets, fragments, yarns, strips, or sheets. The solid aerosol-forming substrate may be deposited on the surface of the carrier, for example, in the form of a sheet, foam, gel, or slurry. The solid aerosol-forming substrate may be deposited over the entire surface of the carrier, or alternatively, in a pattern to provide non-uniform flavor delivery during use.

[0118] In preferred embodiments, the aerosol-forming substrate comprises homogenized tobacco material. As used herein, the term “homogenized tobacco material” refers to material formed by agglomerating particulate tobacco.

[0119] The aerosol-forming substrate preferably comprises an aggregate of homogenized tobacco material sheets. As used herein, the term “sheet” refers to a layered element having a width and length substantially greater than its thickness. As used herein, the term “aggregated” is used to describe a sheet that is wrapped, folded, or otherwise compressed or clamped substantially transversely to the longitudinal axis of the aerosol-generating article. Preferably, the aerosol-forming substrate comprises an aerosol-forming compound. As used herein, the term “aerosol-forming compound” is used to describe any suitable known compound or mixture of compounds that facilitates aerosol formation during use and is substantially resistant to thermal decomposition at the operating temperature of the aerosol-generating article.

[0120] Suitable aerosol-forming materials are known in the art and include, but are not limited to, polyhydric alcohols (such as propylene glycol, triethylene glycol, 1,3-butanediol, and glycerin), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, or triacetate), and aliphatic esters of monocarboxylic acids, dicarboxylic acids, or polycarboxylic acids (such as dimethyl dodecanediate and dimethyl tetradecanediate). Preferred aerosol-forming materials are polyhydric alcohols or mixtures thereof (such as propylene glycol, triethylene glycol, 1,3-butanediol, and most preferably glycerin).

[0121] The aerosol-forming substrate may comprise a single aerosol-forming body. Alternatively, the aerosol-forming substrate may comprise a combination of two or more aerosol-forming bodies. [Examples]

[0122] The present invention is defined in the claims. However, a non-exclusive list of non-limiting embodiments is provided below. One or more features of these embodiments may be combined with one or more features of any of the features described above, for example, one or more features of other embodiments, forms, or aspects described herein.

[0123] Example 1: A method for forming an inductor coil for an aerosol generator, To provide a tube made of conductive material, A method comprising cutting a helical opening in at least a portion of a tube of conductive material to define a helical coil of conductive material, wherein the helical coil of conductive material forms an inductor coil for an aerosol generator. Example 2: The method according to Example 1, wherein the step of cutting a spiral opening includes rotating and advancing a tube of conductive material relative to a fixed cutting device. Example 3: The method according to Example 1 or 2, wherein the step of providing a tube of conductive material includes positioning the tube of conductive material on a mandrel. Example 4: The method according to Example 2 or 3, wherein rotating and advancing a tube of conductive material simultaneously involves rotating the tube of conductive material around a mandrel and advancing the tube of conductive material along the mandrel. Example 5: The method according to any one of Examples 1 to 4, wherein the cutting step includes cutting a helical opening in only a portion of the tube of conductive material to define a first end portion of the tube, a second end portion of the tube, and a central portion of the tube extending between the first end portion and the second end portion, and the helical opening extends only along the central portion of the tube such that the inductor coil includes the first end portion and the second end portion of the tube, and the helical coil of conductive material extends between the first end portion and the second end portion of the tube. Example 6: The method according to Embodiment 5, wherein the first end portion of the tube, the second end portion of the tube, and each winding of the helical coil have a maximum width extending in a direction parallel to the longitudinal axis of the tube, and the maximum width of the first end portion of the tube and the second end portion of the tube, respectively, is greater than the maximum width of each winding of the helical coil. Example 7: The method according to Example 5 or 6, wherein the cutting step further includes cutting a plurality of separate openings in at least one of the first end portion of the conductive material tube and the second end portion of the conductive material tube. Example 8: The method according to Example 7, wherein the step of cutting multiple individual openings includes cutting multiple individual openings in both the first end portion of the conductive material tube and the second end portion of the conductive material tube. Example 9: The method according to Example 7 or 8, wherein multiple individual openings are distributed symmetrically in the circumferential direction extending around the longitudinal axis of the conductive material tube. Example 10: The method according to Example 7, 8, or 9, wherein each individual opening has a circular, triangular, rectangular, pentagonal, hexagonal, heptagonal, or octagonal shape. Example 11: The method according to any one of Examples 1 to 10, further comprising the step of providing a layer of electrical insulating material around the outer surface of a tube of conductive material. Example 12: The method according to Example 11, wherein the step of providing a layer of electrical insulating material includes winding a piece of electrical insulating material around the outer surface of a tube of conductive material. Example 13: The method according to Example 12, wherein the winding step includes winding a helical strip of electrical insulating material around the outer surface of a tube made of conductive material. Example 14: The method according to Example 13, wherein a helical strip of electrical insulating material is wrapped around the outer surface of a tube of conductive material in a first direction, and a helical opening extends around the tube of conductive material in a second direction, the second direction being opposite to the first direction. Example 15: The method according to Example 11, wherein the step of providing a layer of electrical insulating material includes overmolding the outer surface of a conductive material tube with electrical insulating material. Example 16: The method according to any one of Examples 1 to 15, wherein the tube of conductive material has an inner surface, and the method further comprises forming at least one edge of a winding of a helical coil of conductive material on the inner surface of the tube of conductive material. Example 17: The method according to Example 16, wherein the molding step includes providing a bevel, chamfer, or fillet on at least one edge of the winding of a helical coil of conductive material. Example 18: The method according to Example 16 or 17, wherein the molding step includes at least one of cutting and / or machining at least one edge of the winding of a helical coil of conductive material. Example 19: The method according to any one of Examples 1 to 18, wherein the cutting step includes cutting a tube of conductive material using a laser cutter. Example 20: The method according to any one of Examples 1 to 19, further comprising the step of repeatedly cutting a tube of conductive material along its length to form a plurality of connected inductor coils along the tube of conductive material. Example 21: The method according to Example 20, further comprising cutting a tube of conductive material between a series of connected inductor coils to form a plurality of individual inductor coils. Example 22: An inductor coil formed using the method described in any of Examples 1 to 21. Example 23: An inductor coil for an aerosol generator, The first tubular portion of the conductive material, The second tubular portion of the conductive material, and An inductor coil comprising a helical coil of conductive material extending between a first tubular portion of conductive material and a second tubular portion of conductive material. Example 24: The inductor coil according to Example 23, wherein the helical coil is integrally formed with the first tubular portion and the second tubular portion. Example 25: The inductor coil according to Example 23 or 24, wherein each of the first tubular portion, the second tubular portion, and each winding of the helical coil has a maximum width extending in a direction parallel to the longitudinal axis of the inductor coil, and the maximum width of each of the first tubular portion and the second tubular portion is greater than the maximum width of each winding of the helical coil. Example 26: The inductor coil according to Example 23, 24, or 25, further comprising a plurality of individual openings provided in at least one of a first tubular portion of a conductive material and a second tubular portion of a conductive material. Example 27: The inductor coil according to Embodiment 26, further comprising a plurality of separate openings provided in both a first tubular portion and a second tubular portion of the conductive material. Example 28: An inductor coil according to Example 26 or 27, wherein multiple individual openings are distributed symmetrically in the circumferential direction extending around the longitudinal axis of a tube of conductive material. Example 29: The inductor coil according to Example 26, 27, or 28, wherein each individual opening has a circular, triangular, rectangular, pentagonal, hexagonal, heptagonal, or octagonal shape. Example 30: An inductor coil according to any of Examples 23 to 29, further comprising a layer of electrical insulating material extending around a first tubular portion, a second tubular portion, and the outer surface of a helical coil. Example 31: An inductor coil according to Example 30, wherein the layer of electrical insulating material includes a strip of electrical insulating material extending around a first tubular portion, a second tubular portion, and the outer surface of a helical coil. Example 32: An inductor coil according to Example 31, wherein a strip of electrical insulating material extends spirally around a first tubular portion, a second tubular portion, and the outer surface of a helical coil. Example 33: An inductor coil according to Example 32, wherein a helical strip of electrical insulating material is wound in a first direction, and the helical coil is wound in a second direction, the second direction being opposite to the first direction. Example 34: An inductor coil according to Example 30, wherein an electrical insulating layer is overmolded onto the outer surfaces of the first tubular portion, the second tubular portion, and the helical coil. Example 35: An inductor coil according to any one of Examples 23 to 34, wherein a helical coil of a conductive material has an inner surface, and at least one edge of the winding of the helical coil includes a bevel, chamfer, or fillet. Example 36: Aerosol generator, An inductor coil as described in any of Examples 22 to 35, A chamber for receiving at least a portion of an aerosol-generating article, and An aerosol generator comprising a power supply and control circuit connected to an inductor coil, configured to supply alternating current to the inductor coil so that the inductor coil generates an alternating magnetic field when in use. Example 37: The aerosol generator according to Example 36, wherein the chamber includes an open first end through which at least a portion of an aerosol-generating article may be inserted into the chamber, and a closed second end opposite to the open first end. Example 38: The aerosol generator according to Example 37, further comprising at least one projection extending into the chamber from a closed second end of the chamber. Example 39: The aerosol generator according to Example 38, wherein at least one projection includes at least three projections. Example 40: The aerosol generator according to Embodiment 39, wherein the chamber has a longitudinal axis defining a first direction along which at least a portion of an aerosol generating article may be inserted into the chamber, and at least three protrusions are spaced equidistant from each other in the circumferential direction around the longitudinal axis. Example 41: An aerosol generator according to any one of Examples 36 to 40, further comprising a housing, wherein an inductor coil, a power supply, and a control circuit are arranged within the housing. Example 42: An aerosol generator, in combination with Example 41 and any of Examples 37-40, wherein the housing comprises an end wall defining a closed second end of the chamber, and at least one projection extending from the end wall into the chamber. Example 43: An aerosol generator according to Example 42, wherein at least one protrusion is integrally formed with the end wall. Example 44: An aerosol generator according to any one of Examples 37 to 43, further comprising an elongated susceptor element extending into the chamber from a closed second end of the chamber. Example 45: The aerosol generator according to Example 44, wherein at least a portion of the elongated susceptor element is positioned inside the inductor coil. Example 46: An aerosol generator according to any one of Examples 36 to 45, wherein the inductor coil is arranged such that at least a portion of the aerosol generating article is received within the inductor coil when the aerosol generating article is inserted into the chamber. Example 47: Aerosol generation system, an aerosol generator according to any one of Examples 36 to 46, and An aerosol generating system comprising an aerosol generating article having an aerosol-forming substrate. Example 48: The aerosol generating system according to Example 47, wherein the aerosol generating article further comprises an article susceptor element. Example 49: The aerosol generating system according to Embodiment 48, wherein the aerosol generating article is configured such that at least a portion of the article susceptor element is positioned within the inductor coil when the aerosol generating article is inserted into the chamber. [Brief explanation of the drawing]

[0124] The present invention will be further described, for illustrative purposes only, with reference to the attached drawings.

[0125] [Figure 1] Figure 1 shows a side cross-sectional view of an aerosol generator equipped with an inductor coil according to a first embodiment of the present invention. [Figure 2] Figure 2 shows a partial cutaway view of the aerosol generator shown in Figure 1, illustrating the outer surface of the inductor coil. [Figure 3] Figure 3 shows an axial cross-sectional view of the aerosol generator shown in Figure 1 along line 1-1. [Figure 4] Figure 4 shows a side cross-sectional view of an aerosol generation system equipped with the aerosol generator shown in Figure 1. [Figure 5] Figure 5 shows a flowchart illustrating a method for forming an inductor coil according to one embodiment of the present invention. [Figure 6] Figure 6 is a cross-sectional view of the inductor coil windings in Figure 1, showing the first arrangement of the windings. [Figure 7] Figure 7 is a cross-sectional view of the inductor coil windings in Figure 1, showing the second winding arrangement. [Figure 8] Figure 8 shows a side cross-sectional view of an aerosol generator according to a second embodiment of the present invention. [Figure 9] Figure 9 shows a side cross-sectional view of an aerosol generation system equipped with the aerosol generator shown in Figure 8. [Figure 10] Figure 10 shows a side cross-sectional view of an aerosol generator according to a third embodiment of the present invention. [Figure 11] Figure 11 shows a side cross-sectional view of an aerosol generator according to a fourth embodiment of the present invention. [Modes for carrying out the invention]

[0126] Figures 1 to 3 show an aerosol generator 10 according to a first embodiment of the present invention. The aerosol generator 10 comprises a housing 12 defining a chamber 16 for receiving a portion of an aerosol generating article. The chamber 16 comprises an open end 18 through which the aerosol generating article may be inserted into the chamber 16, and a closed end 20 opposite the open end 18. The cylindrical wall 22 of the chamber 16 extends between the open end 18 and the closed end 20.

[0127] The aerosol generator 10 also includes an inductor coil 24 containing a plurality of windings 26 positioned within the chamber 16. The inductor coil 24 is formed from a conductive metal tube 27 with a helical opening 29 formed to define the plurality of windings 26. The plurality of windings 26 form a helical coil of conductive material extending between a first tubular portion of conductive material formed by a first end of the metal tube 27 and a second tubular portion of conductive material formed by a second end of the metal tube 27. The metal tube 27 defines a lumen 28 into which a portion of the aerosol generating article is received when the aerosol generating article is inserted into the chamber 16. Advantageously, positioning the inductor coil 24 in direct contact with the aerosol generating article received within the chamber 16 facilitates the transfer of heat generated by the resistive heating of the inductor coil 24 to the aerosol generating article.

[0128] The metal tube 27 includes a plurality of notches 30 at its first end, which is positioned toward the open end 18 of the chamber 16. Thus, the plurality of notches 30 extend through the first tubular portion of the conductive material. Advantageously, the plurality of notches 30 reduce the weight of the inductor coil 24 and reduce heat losses that may arise from heat conduction from the winding 26 to the first end of the metal tube 27.

[0129] The metal tube 27 also includes a plurality of airflow openings 32 at a second end of the metal tube 27 positioned toward the closed end 20 of the chamber 16. Thus, the plurality of airflow openings 32 extend through the second tubular portion of the conductive material. Advantageously, the plurality of airflow openings 32 provide fluid communication between the outside and inside of the metal tube 27, as will be further described below.

[0130] The housing 12 defines a plurality of first projections 37 and a plurality of second projections 38, each extending into the chamber 16. Advantageously, the first projections 37 and the second projections 38 support the metal tube 27 within the chamber 16 so that the inductor coil 24 is positioned coaxially with the central axis 36 of the aerosol generator 10. Advantageously, positioning the inductor coil to extend concentrically around the central axis 36 of the aerosol generator 10 facilitates the insertion of the aerosol generating article into the chamber 16. Furthermore, the first projections 37 and the second projections 38 position the metal tube 27 such that its outer surface is spaced apart from the cylindrical wall 22 of the chamber 16. By spaced the outer surface of the metal tube 27 apart from the cylindrical wall 22 of the chamber 16, an annular gap 34 is defined between the cylindrical wall 22 of the chamber 16 and the outer surface of the metal tube 27. Advantageously, the annular gap 34 reduces or minimizes the transfer of heat generated by the resistive heating of the inductor coil 24 to the housing 12. Advantageously, the annular gap 34 facilitates the airflow through the chamber 16 when the aerosol-generating article is received into the chamber 16.

[0131] Multiple first projections 37 contact the outer surface of the metal tube 27. Each of the multiple second projections 38 is received in a corresponding slot defined by the second end of the metal tube 27. As further described below, the multiple second projections 38 also function to maintain a gap between the end of the aerosol generating article and the closed end 20 of the chamber 16 when the aerosol generating article is fully inserted into the chamber 16. In the embodiments shown in Figures 1 to 3, the housing 12 defines three first projections 37 and three second projections 38 that are equidistant around the central axis 36 of the aerosol generator 10. Preferably, the multiple first projections 37 are rotationally offset from the multiple second projections 38 around the central axis 36 to increase or maximize the stability of the metal tube 27 in the chamber 16. Those skilled in the art will understand that the housing 12 may define more or fewer of each of the first projection 37 and the second projection 38, and the arrangement of the first and second projections 37, 38 within the chamber 16 may be changed.

[0132] The aerosol generator 10 also includes a control circuit 40 and a power supply 42 connected to an inductor coil 24. The control circuit 40 is configured to supply alternating current from the power supply 42 to the inductor coil 24 in order to generate an alternating magnetic field. A pressure sensor 46 is positioned in fluid communication with the annular gap 34 between the inductor coil 24 and the cylindrical wall 22 of the chamber 16. During use of the aerosol generator 10, the pressure sensor 46 supplies a signal to the control circuit 40 indicating the air pressure in the annular gap 34.

[0133] Figure 4 shows a cross-sectional view of an aerosol generating system 100 comprising the aerosol generating device 10 and the aerosol generating article 102 shown in Figure 1.

[0134] The aerosol generating article 102 comprises an aerosol-forming substrate 104 in the form of a cigarette plug, a first hollow acetate tube 106, a second hollow acetate tube 108, a mouthpiece 110, and an outer wrapper 112. The aerosol generating article 102 also comprises a susceptor element 114 disposed within the aerosol-forming substrate 104. During use, a portion of the aerosol generating article 102 is inserted into the chamber 16 and the inductor coil 24 such that the aerosol-forming substrate 104 and the susceptor element 114 are located inside the windings 26 of the inductor coil 24. The control circuit 40 supplies alternating current from the power supply 42 to the inductor coil 24, generating an alternating magnetic field that inductively heats the susceptor element 114, which heats the aerosol-forming substrate 104 and generates an aerosol.

[0135] The airflow through the aerosol generating system 100 in use is illustrated by the dashed line 116 in Figure 3. When a user inhales the mouthpiece 110 of the aerosol generating article 102, a negative pressure is generated in the chamber 16. This negative pressure is sensed by a pressure sensor 46, which provides a signal to the control circuit 40 indicating that the user has inhaled the mouthpiece 110. Advantageously, positioning the pressure sensor 46 to be in fluid communication with a narrow annular gap 34 amplifies the pressure drop sensed by the pressure sensor 46, increasing its sensitivity to user inhalation. In response to the signal from the pressure sensor 46, the control circuit 40 can turn on or increase the power supplied from the power supply 42 to the inductor coil 24.

[0136] The negative pressure created by the user inhaling through the mouthpiece 110 draws air into the chamber 16 at the open end 18 of the chamber. The air that enters the chamber 16 flows through the annular gap 34 between the metal tube 27 and the cylindrical wall 22 of the chamber 16. When the airflow reaches the closed end 20 of the chamber 16, the air flows through the airflow opening 32 at the second end of the metal tube 27 and enters the aerosol generating article 102 through the aerosol forming substrate 104. The airflow through the airflow opening 32 is facilitated by a second projection 38 that receives the upstream end of the aerosol generating article 102, thereby preventing the aerosol generating article 102 from obstructing the airflow opening 32.

[0137] As the airflow passes through the aerosol-forming substrate 104, the aerosol generated by the heating of the aerosol-forming substrate 104 is carried into the airflow. The aerosol then flows along the length of the aerosol-generating article 102 and through the mouthpiece 110 to the user.

[0138] Figure 5 is a flowchart illustrating a method 200 for forming an inductor coil for an aerosol generator. While the method 200 is described in context with reference to the inductor coil 24 in Figures 1-3, those skilled in the art will understand that the method 200 is not limited to forming the inductor coil 24 and may be used to form inductor coils according to alternative embodiments.

[0139] In the first step, Method 200 includes providing a tube 202 of a conductive material, such as a metal tube 27. In the second step, the metal tube 27 is mounted on a rotatable mandrel 204 to facilitate the formation of an inductor coil 24 from the metal tube 27. In the third step, Method includes defining a helical coil containing a plurality of windings 26 that form the inductor coil 24 by cutting a helical opening 29 in at least a portion of the tube 27 206. The cutting step 206 may be carried out with a fixed laser cutter, and the mandrel is simultaneously advanced and rotated relative to the laser cutter to form the helical opening 29 in the metal tube 27. The fourth step includes forming a plurality of openings within the metal tube 27, such as a plurality of notches 30 and a plurality of airflow openings 32 208. The openings may be formed using the same technique as for forming the helical opening 29, such as a laser cutter. Those skilled in the art will understand that the forming step 208 may be performed before, after, or simultaneously with the cutting step 206.

[0140] In the final step, the inner surface of the inductor coil 24 may be machined 210 to facilitate the insertion of an aerosol-generating article into the inductor coil 24. Figure 6 shows a first example of an inductor coil 24 in which each of the windings 26 is machined to provide a chamfered edge 212 that faces the aerosol-generating article when the aerosol-generating article is inserted into the inductor coil 24 along a first direction 214. Figure 7 shows a second example in which each of the windings 26 is instead machined to form a rounded surface 216 that faces the aerosol-generating article when the aerosol-generating article is inserted into the inductor coil 24 along a first direction 214. Advantageously, by machining only one edge of each winding 26, the insertion of the aerosol-generating article into the inductor coil 24 is facilitated, and the retention of the aerosol-generating article within the inductor coil 24 is facilitated. The unformed edges of each winding 26 resist the removal of the aerosol-generating article from the inductor coil 24 until the aerosol-generating article shrinks during use of the aerosol-generating system 100.

[0141] Figure 8 shows a cross-sectional view of an aerosol generator 300 according to a second embodiment of the present invention. The aerosol generator 300 is similar to the aerosol generator 10 described with reference to Figures 1 to 3, and the same reference numerals are used to specify similar parts.

[0142] The aerosol generator 300 differs from the aerosol generator 10 only in the addition of a susceptor element 314. The susceptor element 314 has an elongated shape and extends into the chamber 16 from the closed end 20 of the chamber 16. The susceptor element 314 extends along the central axis 36 of the aerosol generator 300 such that the inductor coil 24 extends concentrically around the susceptor element 314.

[0143] Figure 9 shows a cross-sectional view of an aerosol generating system 370 comprising the aerosol generating device 300 and the aerosol generating article 172 shown in Figure 8. The aerosol generating system 370 is similar to the aerosol generating system 100 described with reference to Figure 4, and the same reference numerals are used to specify similar parts.

[0144] The aerosol generating system 370 differs only in the absence of a susceptor element in the aerosol generating article 372. When the aerosol generating article 372 is inserted into the chamber 16, the susceptor element 314 of the aerosol generating device 300 is received into the aerosol forming substrate 104 of the aerosol generating article 372. With the aerosol generating article 372 inserted into the chamber 16, the operation of the aerosol generating system 370 is identical to the operation of the aerosol generating system 100 described with respect to Figure 4.

[0145] Figure 10 shows a cross-sectional view of an aerosol generator 400 according to a third embodiment of the present invention. The aerosol generator 400 is similar to the aerosol generator 10 described with reference to Figures 1 to 3, and the same reference numerals are used to specify similar parts.

[0146] The aerosol generator 400 differs from the aerosol generator 10 by the configuration of multiple notches 430 and multiple airflow openings 432 within the metal tube 427 of the inductor coil 424. Specifically, in the aerosol generator 400, each of the notches 430 and airflow openings 432 has a larger hexagonal shape compared to the smaller circular shapes of the notches 30 and airflow openings 32 in the aerosol generator 10. Advantageously, the larger size of the notches 430 and airflow openings 432 further reduces the weight of the inductor coil 24 and further reduces the heat generated in the windings 426 conducted toward the first and second ends of the metal tube 427. Advantageously, the hexagonal shape of the notches 430 facilitates the nesting of notches 430 in adjacent rows.

[0147] The operation and use of the aerosol generator 400 are the same as those of the aerosol generator 10 described above. Those skilled in the art will understand that the aerosol generator 400 may be modified to include the susceptor element described above with respect to the aerosol generator 300.

[0148] Figure 11 shows a cross-sectional view of an aerosol generator 500 according to a fourth embodiment of the present invention. The aerosol generator 500 is similar to the aerosol generator 10 described with reference to Figures 1 to 3, and the same reference numerals are used to specify similar parts.

[0149] The aerosol generator 500 differs from the aerosol generator 10 in the configuration of the inductor coil 524. Specifically, the metal tube 527 used to form the inductor coil 524 is shorter and defines only a plurality of windings 526. In other words, the metal tube 527 does not define any notches or airflow openings at its first and second ends. Because the metal tube 527 has no airflow openings, it is positioned so that its second end abuts against a plurality of second projections 38 such that the second end of the metal tube 527 is spaced apart from the closed end 20 of the chamber 16. The space between the second end of the metal tube 527 and the closed end 20 of the chamber 16 allows air to flow from the annular gap 34 into the aerosol generating article received in the inductor coil 524 during use of the aerosol generator 500.

[0150] The operation and use of the aerosol generator 500 are the same as those of the aerosol generator 10 described above. Those skilled in the art will understand that the aerosol generator 500 may be modified to include the susceptor element described above with respect to the aerosol generator 300.

Claims

1. An inductor coil, The first tubular portion of the conductive material, The second tubular portion of the conductive material, and An inductor coil comprising a helical coil of conductive material extending between a first tubular portion of the conductive material and a second tubular portion of the conductive material, A chamber for receiving at least a portion of an aerosol-generating article, wherein when the aerosol-generating article is inserted into the chamber, at least a portion of the aerosol-generating article is received within the inductor coil, and the inductor coil is arranged so as to be in direct contact with the aerosol-generating article; An aerosol generator comprising a power supply and control circuit connected to the inductor coil and configured to supply an alternating current to the inductor coil so that the inductor coil generates an alternating magnetic field when in use.

2. The aerosol generating apparatus according to claim 1, wherein the helical coil is integrally formed with the first tubular portion and the second tubular portion.

3. The aerosol generator according to claim 1 or 2, wherein each of the first tubular portion, the second tubular portion, and each winding of the helical coil has a maximum width extending in a direction parallel to the longitudinal axis of the inductor coil, and the maximum width of each of the first tubular portion and the second tubular portion is greater than the maximum width of each winding of the helical coil.

4. The aerosol generating apparatus according to any one of claims 1 to 3, further comprising a plurality of individual openings in at least one of the first tubular portion of the conductive material and the second tubular portion of the conductive material.

5. The aerosol generator according to claim 4, further comprising a plurality of individual openings in both the first tubular portion and the second tubular portion of the conductive material.

6. The aerosol generator according to claim 4 or 5, wherein the plurality of individual openings are distributed symmetrically in the circumferential direction extending around the longitudinal axis of the inductor coil.

7. The aerosol generator according to any one of claims 1 to 6, further comprising a layer of electrical insulating material extending around the first tubular portion, the second tubular portion, and the outer surface of the helical coil.

8. The aerosol generator according to any one of claims 1 to 7, wherein the helical coil of the conductive material has an inner surface, and at least one edge of the winding of the helical coil includes a bevel, chamfer, or fillet.

9. The aerosol generating apparatus according to any one of claims 1 to 8, further comprising a susceptor element.

10. The aerosol generator according to any one of claims 1 to 9, wherein the chamber includes an open first end through which at least a portion of an aerosol generating article can be inserted into the chamber, and a closed second end opposite to the open first end.

11. an aerosol generation system, an aerosol generator according to any one of claims 1 to 10, An aerosol generating system comprising an aerosol generating article having an aerosol-forming substrate.

12. A method for forming an inductor coil for an aerosol generator, To provide a tube made of conductive material, The method involves cutting a helical opening in at least a portion of the tube of the conductive material to define a helical coil of the conductive material, wherein the helical coil of the conductive material forms an inductor coil for an aerosol generator. A method comprising cutting a plurality of individual openings in a tube of the conductive material.

13. The method according to claim 12, wherein the step of cutting the helical opening includes cutting the helical opening in only a portion of the tube of the conductive material to define a first end portion of the tube, a second end portion of the tube, and a central portion of the tube extending between the first end portion and the second end portion, and the helical opening extends only along the central portion of the tube such that the inductor coil includes the first end portion and the second end portion of the tube, and the helical coil of the conductive material extends between the first end portion and the second end portion of the tube.

14. The method according to claim 13, wherein the step of cutting the plurality of individual openings includes cutting the plurality of individual openings in at least one of the first end portion of the tube of the conductive material and the second end portion of the tube of the conductive material.

15. The method according to claim 13, wherein the step of cutting the plurality of individual openings includes cutting the plurality of individual openings in both the first end portion of the conductive material tube and the second end portion of the conductive material tube.

16. The method according to any one of claims 13 to 15, wherein the first end portion of the tube, the second end portion of the tube, and each winding of the helical coil have a maximum width extending in a direction parallel to the longitudinal axis of the tube, and the maximum width of the first end portion of the tube and the second end portion of the tube, respectively, is greater than the maximum width of each winding of the helical coil.

17. The method according to any one of claims 12 to 16, wherein the step of cutting the helical opening includes rotating and advancing the tube of the conductive material relative to a fixed cutting device.

18. The method according to any one of claims 12 to 17, wherein the tube of the conductive material has an inner surface, and the method further comprises forming at least one edge of a winding of a helical coil of the conductive material on the inner surface of the tube of the conductive material.

19. The method according to claim 18, wherein the molding step includes providing a bevel, chamfer, or fillet on at least one edge of the winding of the helical coil of the conductive material.

20. The method according to any one of claims 12 to 19, further comprising at least repeating the step of cutting the helical coil along the length of the tube of the conductive material to form a plurality of connected inductor coils along the tube of the conductive material.

21. The method according to claim 20, further comprising cutting the tube of conductive material between a series of connected inductor coils to form a plurality of individual inductor coils.

22. An inductor coil formed using the method according to any one of claims 12 to 21.

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