Aerosol supply device

Abstract

To provide a method for forming an inductor coil for an aerosol supply device.SOLUTION: A method for forming an aerosol supply device inductor coil includes a step for preparing a litz wire having a plurality of wire strands, each of the plurality of wire strands including a bondable coating. The method includes a step for forming an inductor coil from the litz wire on a support member, the inductor coil having a predetermined shape. The method further includes a step for activating the bondable coating so that the inductor coil substantially holds the predetermined shape, and a step for removing the inductor coil from the support member.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a method for forming an inductor coil for an aerosol supply device and an aerosol supply device. Background

[0002] Smoking articles such as cigarettes, cigars, and the like create tobacco smoke by burning tobacco during use. Attempts have been made to provide alternatives to these articles that burn tobacco by creating products that release compounds without combustion. An example of such a product is a heating device that releases compounds by heating rather than burning a material. The material can be, for example, tobacco or other non-tobacco products, which may or may not contain nicotine. Summary

[0003] According to a first aspect of the present disclosure, a method for forming an aerosol supply device inductor coil, comprising: providing a litz wire comprising a plurality of wire strands, each of the plurality of wire strands comprising a joinable coating; forming an inductor coil from the litz wire on a support member, the inductor coil having a predetermined shape; activating the joinable coating so that the inductor coil substantially retains the predetermined shape; and removing the inductor coil from the support member. A method is provided that includes these steps.

[0004] According to a second aspect of the present disclosure, an aerosol supply device induction coil formed from a litz wire comprising a plurality of wire strands, each of the wire strands having a joinable coating, the joinable coating being activated so that the aerosol supply device induction coil substantially retains its own shape without a support member. An aerosol supply device induction coil is provided.

[0005] Further features and advantages of the present invention will become apparent from the following description of the preferred embodiments of the present invention, provided by way of example only, with reference to the accompanying drawings.

Brief Description of the Drawings

[0006]

Figure 1

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Figure 10

[0007] As used herein, the term "aerosol - generating material" includes materials that, when heated, provide volatilized components, typically in the form of an aerosol. The aerosol - generating material includes any tobacco - containing material and can include, for example, one or more of tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco, or tobacco substitutes. The aerosol - generating material can also include other non - tobacco products, which may or may not contain nicotine depending on the product. The aerosol - generating material can be in the form of, for example, a solid, liquid, gel, wax, or the like. The aerosol - generating material can also be, for example, a combination or mixture of materials. The aerosol - generating material may also be known as a "smoking material".

[0008] Typically, devices are known that heat an aerosol - generating material to volatilize at least one component of the aerosol - generating material to form an aerosol that can be inhaled without burning or combusting the aerosol - generating material. Such devices are sometimes described as "aerosol - generating devices", "aerosol - supplying devices", "non - combustion heating devices", "tobacco - heated product devices", or "tobacco - heating devices", or the like. Similarly, there are so - called e - cigarette devices that vaporize an aerosol - generating material, typically in liquid form, which may or may not contain nicotine. The aerosol - generating material can be in the form of a rod, cartridge, or cassette, or the like, that can be inserted into the device or provided as part thereof. A heater for heating and volatilizing the aerosol - generating material can be provided as a "permanent" part of the device.

[0009] The aerosol supply device can receive an article comprising an aerosol - generating material for heating. The "article" in this context is a component that contains, or contains at the time of use, the aerosol - generating material and optionally other components at the time of use, and this aerosol - generating material is heated to volatilize the aerosol - generating material. The user can insert this article into the aerosol supply device before the article is heated to generate an aerosol that the user will later inhale. The article can be of a predefined or specific size, for example, configured to be placed within a heating chamber of a device sized to receive the article.

[0010] A first aspect of the present disclosure defines a method of forming an inductor coil for use in an aerosol supply device. The method begins with a litz wire / cable. A litz wire is a wire comprising a plurality of wire strands and is used to conduct alternating current. A litz wire is used to reduce skin - effect losses within the conductor and comprises a plurality of individually insulated wires that are twisted or woven together. The result of this winding is to equalize the proportion of the total length that each strand is on the outside of the conductor. This has the effect of equally distributing the alternating current among the wire strands and reducing the resistance within the wire. In some examples, the litz wire comprises several bundles of wire strands, and the wire strands within each bundle are twisted together. The bundles of wire are twisted / woven together in a similar manner.

[0011] In the present disclosure, each of a plurality of wire strands comprises a joinable coating. The joinable coating is a coating that surrounds each wire strand and can be activated (such as by heating) so that a strand within a litz wire joins to another adjacent strand. The joinable coating enables the litz wire to be formed into the shape of an inductor coil on a support member, and after the joinable coating is activated, the inductor coil retains its shape. Thus, the joinable coating “sets” the shape of the inductor coil. In some examples, the joinable coating is an electrically insulating layer that surrounds a conductive core. However, the joinable coating and the insulator may be separate layers, with the joinable coating surrounding the insulating layer. In an example, the conductive core of the litz wire comprises copper.

[0012] The litz wire (then in the shape of an inductor coil) can be removed from the support member without losing its shape. The support member is a structure used to form the litz wire into a predefined shape (i.e., the shape of an inductor coil). Thus, the support member holds the litz wire in a predefined shape when the joinable coating is activated.

[0013] Thus, an exemplary method provides an inductor coil that is likely to retain its shape over time. Therefore, after the device is assembled, the desired heating effect can be maintained longer, which increases the lifespan of the device and ensures that the inductor coil is operating most efficiently. This is in contrast to devices having an inductor coil that can deform or distort over time. The method also provides an additional level of flexibility during the manufacture of the device. For example, the inductor coil can be prepared prior to the assembly process rather than when the device is assembled.

[0014] The above method can be used to form an inductor coil for use in an aerosol supply device. In some examples, the device may comprise two or more inductor coils. Each inductor coil is arranged to generate a varying magnetic field that penetrates the susceptor. As described in more detail herein, the susceptor is a conductive object that can be heated by the varying magnetic field. An article comprising an aerosol-generating material can be received within the susceptor, or disposed near the susceptor, or in contact with the susceptor. Once heated, the susceptor transfers heat to the aerosol-generating material, thereby releasing an aerosol.

[0015] In certain examples, the step of forming the inductor coil includes winding a litz wire around a support member so as to form a helical inductor coil. Thus, the inductor coil can have a helical shape. For example, the support member may be tubular or cylindrical, and the litz wire can be wound around the support member into a predefined helical shape. Accordingly, the support member can have an outer cross-section that defines a predefined shape. For example, the support member can have a first outer cross-section, the helical coil can have a second inner cross-section, and the first outer cross-section and the second inner cross-section can be substantially the same. The first and second cross-sections can be, for example, circular in shape. By winding the litz wire around and along the length of the support member, a helical inductor coil can be formed.

[0016] The method may further include receiving the inductor coil on an insulating member / support after removing the inductor coil from the support member. The insulating member can be, for example, a component disposed within the aerosol supply device. The insulating member can have a third outer cross-section that is substantially equal to the first outer cross-section.

[0017] In other examples, the inductor coil can have a flat shape, a curved shape, or a shape such as a hyperbolic paraboloid.

[0018] The predefined shape may include a connection portion for connecting the inductor coil to a power source at one or more ends of the inductor coil. In other words, at least one end of the inductor coil and the litz wire may define the connection portion. A connection portion may exist at each end of the inductor coil. The connection portion(s) may be connectable to a circuit such as a printed circuit board (PCB), for example. The method may include the step of immersing the connection portion in solder for a period of time. The molten solder acts to melt the insulator or separately remove the insulator from the plurality of wire strands to create good electrical contact between each of the wire strands and the component to which the inductor coil is connected. Thus, at the connection portion, each (or most) of the wire strands are electrically connected to each other by solder that adheres / bonds to the inductor coil. The connector portion comprises the portion (such as an end) of the inductor coil that is connected to the power source.

[0019] The period during which the connection portion is immersed in solder may be, for example, from about 2 seconds to about 6 seconds, or from about 3 seconds to about 5 seconds. It has been found that this length of time provides a good balance between removing the insulator (and bondable coating) from the wire strands without damaging the conductive core of the wire strands and creating good electrical connection. The period is preferably from about 4 seconds to about 5 seconds. This provides a good balance between the above considerations.

[0020] The solder in which the connection portion is immersed may have a temperature of from about 400°C to about 500°C, or from about 400°C to about 450°C. It has been found that solder at this temperature is suitable for removing the insulator (and bondable coating) from the wire strands without damaging the conductive core of the wire strands. The solder preferably may have a temperature of about 450°C.

[0021] The step of activating the joinable coating may include heating the joinable coating. For example, after the induction coil is formed on the support member, the litz wire may be heated so that the induction coil undergoes thermosetting, causing the joinable coating on each of the wire strands to self-join. In certain examples, heating the joinable coating includes heating the joinable coating to a joining temperature of about 180 - 200 °C.

[0022] In another example, the joinable coating may be activated via a solvent.

[0023] The method may further include the step of cooling the induction coil after activating the joinable coating. This process can cool the joinable coating and thus set the shape of the induction coil. The step of cooling the induction coil may include passing air through the induction coil. For example, an air gun or a fan can blow air into the induction coil. Using an air gun or a fan can speed up the cooling process.

[0024] As described above, the induction coil may comprise two connection portions, one disposed towards each end of the induction coil. In one example, the predefined shape comprises two connection portions, both of which are in substantially the same plane, and the step of forming the induction coil includes bending at least one of the connection portions so that it lies in the plane. For example, the two ends of the induction coil may be on an axis parallel to the axis defined by the induction coil (and also parallel to the longitudinal axis of the susceptor within the assembled aerosol supply device). The plane may be arranged so that it is disposed tangentially to the induction coil.

[0025] Bending at least one of the connection portions may include bending by about 90 degrees. In a particular example, the first connection portion extends tangentially from the helically wound inductor coil, and the second connection portion is bent by about 90 degrees from the tangential direction such that it is in the same plane as the first connection portion. The second portion may initially extend tangentially from the inductor coil before it is bent.

[0026] Wrapping the litz wire may include wrapping the litz wire around the support member about 5 to 9 times. Thus, an inductor coil with about 5 to 9 turns may be formed. In one example, a first inductor coil having about 6 to 7 turns, such as about 6.75 turns, is formed. Therefore, wrapping the litz wire includes wrapping the litz wire around the support member about 6 to 7 times, such as about 6.75 times. In another example, a second inductor coil having about 8 to 9 turns, such as about 8.75 turns, is formed. Therefore, wrapping the litz wire includes wrapping the litz wire around the support member about 8 to 9 times, such as about 8.75 times. A turn is a complete revolution around the axis.

[0027] The litz wire may have a twist direction, and forming the inductor coil may include wrapping the litz wire in the same direction as the twist direction. Thus, the twist direction compliments the winding direction, which means that the wire strands in the litz wire are less likely to untwist.

[0028] The bondable coating may include enamel.

[0029] In one example, the individual wires are Thermobond STP18 wires commercially available from Elektrisola Inc., New Hampshire. These wires have been found to provide excellent compatibility for use in aerosol supply devices. For example, these wires have a relatively high bonding temperature so that the heated susceptor within the device does not re-soften the bondable coating.

[0030] In a second aspect, the aerosol supply device induction coil is formed from a litz wire comprising a plurality of wire strands, each of the wire strands having a bondable coating, and the bondable coating is activated such that the aerosol supply device induction coil substantially retains its own shape without a support member.

[0031] The induction coil may have a connection portion at one end, and the connection portion is coated with solder in electrical contact with substantially all of the wire strands of the litz wire.

[0032] The method described above can be repeated to form a second inductor coil for the aerosol supply device. In one exemplary method, a first inductor coil is formed, a second inductor coil is formed, and the first inductor coil has a shorter length than the second inductor coil. In a particular example, forming the first inductor coil includes winding a first litz wire around a support member over a first length to form a first helical inductor coil, and forming the second inductor coil includes winding a second litz wire around the support member over a second length to form a second helical inductor coil, the first length being shorter than the second length.

[0033] The first length (of the first inductor coil) may be from about 15 mm to about 20 mm, and the second length (of the second inductor coil) may be from about 25 mm to about 30 mm. More specifically, the first length may be about 19 mm (±1 mm), and the second length may be about 28 mm (±1 mm). These lengths have been found to be suitable for providing effective heating of the susceptor while reducing hot smoke.

[0034] The first inductor coil may comprise a first litz wire having a length of from about 250 mm to about 300 mm, and the second inductor coil may comprise a second litz wire having a length of from about 400 mm to about 450 mm. In other words, the length of the wire within each coil is the length when the coil is unwound. For example, the first litz wire may have a length of from about 280 mm to about 290 mm, and the second litz wire may have a length of from about 415 mm to about 425 mm. In a particular configuration, the first litz wire has a length of about 285 mm and the second litz wire has a length of about 420 mm. These lengths have been found to be suitable for providing effective heating of the susceptor while reducing hot smoke.

[0035] The first inductor coil may have a gap between successive turns, and each gap may have a length of about 0.9 mm. The second inductor coil may have a gap between successive turns, and each gap may have a length of about 1 mm. This means that the effect of the susceptor configuration may vary for each inductor coil. More generally, the gap between successive turns may vary for each inductor coil. The gap length is measured in a direction parallel to the longitudinal axis of the device / susceptor. The gap is the portion where there is no wire of the coil (i.e., there is a space between successive turns).

[0036] The first inductor coil may have a mass of about 2 g to about 3 g, and the second inductor coil may have a mass of about 3 g to about 4 g. For example, the first mass may be less than about 3 g, or less than about 2.5 g, and the second mass may be greater than about 3 g, or greater than about 3.5 g. In a particular configuration, the first inductor coil has a mass of about 2.4 g and the second inductor coil has a mass of about 3.5 g.

[0037] Figure 1 shows an example of an aerosol supply device 100 for generating an aerosol from an aerosol-generating medium / material. Broadly, the device 100 can be used to heat a replaceable article 110 comprising an aerosol-generating medium to generate an aerosol or other inhalable medium for inhalation by a user of the device 100.

[0038] The device 100 comprises a housing 102 (in the form of an outer cover) that surrounds and houses the various components of the device 100. The device 100 has an opening 104 at one end through which the article 110 can be inserted for heating by a heating assembly. In use, the article 110 can be inserted fully or partially into the heating assembly where it can be heated by one or more components of the heater assembly.

[0039] The device 100 of this example comprises a first end member 106 with a lid 108 that is movable relative to the first end member 106 to close the opening 104 when the article 110 is not in place. In Figure 1, the lid 108 is shown in an open configuration, but the lid 108 can move to a closed configuration. For example, the user can slide the lid 108 in the direction of arrow "A".

[0040] The device 100 may also include a user-operable control element 112 such as a button or switch that, when pressed, operates the device 100. For example, the user can turn on the device 100 by operating the switch 112.

[0041] Device 100 may also include electrical components such as socket / port 114 that can receive a cable to charge the battery of device 100. For example, socket 114 may be a charging port such as a USB charging port.

[0042] FIG. 2 depicts device 100 of FIG. 1 with outer cover 102 removed and article 110 not present. Device 100 defines a longitudinal axis 134.

[0043] As shown in FIG. 2, first end member 106 is disposed at one end of device 100 and second end member 116 is disposed at the opposite end of device 100. The first and second end members 106, 116 together at least partially define the end surface of device 100. For example, the bottom surface of second end member 116 at least partially defines the bottom surface of device 100. The edge of outer cover 102 may also define a portion of the end surface. In this example, lid 108 also defines a portion of the top surface of device 100.

[0044] The end of the device closest to opening 104 can be known as the proximal end (or mouth-side end) of device 100 because it is closest to the user's mouth during use. During use, the user inserts article 110 into opening 104, activates user control 112 to initiate heating of the aerosol-generating material, and inhales the aerosol generated within the device. This causes the aerosol to flow through device 100 along the flow path towards the proximal end of device 100.

[0045] The other end of the device farthest from opening 104 can be known as the distal end of device 100 because it is farthest from the user's mouth during use. When the user inhales the aerosol generated within the device, the aerosol flows away from the distal end of device 100.

[0046] Device 100 further includes a power source 118. The power source 118 may be a battery, such as a rechargeable battery or a non-rechargeable battery, for example. Examples of suitable batteries include, for example, lithium batteries (such as lithium-ion batteries), nickel batteries (such as nickel-cadmium batteries), and alkaline batteries. The battery is electrically coupled to the heating assembly to supply power when required to heat the aerosol-generating material and under the control of a controller (not shown). In this example, the battery is connected to a central support 120 that holds the battery 118 in place.

[0047] The device further includes at least one electronic device module 122. The electronic device module 122 may include, for example, a printed circuit board (PCB). The PCB 122 may support at least one controller, such as a processor, and memory. The PCB 122 may also include one or more electrical tracks for electrically connecting the various electronic components of the device 100 together. For example, battery terminals may be electrically connected to the PCB 122 so that power can be distributed throughout the device 100. The socket 114 may also be electrically coupled to the battery via an electrical track.

[0048] In exemplary device 100, the heating assembly is an induction heating assembly and comprises various components for heating the aerosol-forming material of article 110 through an induction heating process. Induction heating is a process of heating a conductive object (such as a susceptor) by electromagnetic induction. The induction heating assembly may comprise an induction element, for example, one or more inductor coils, and a device for passing an alternating current, such as a variable current, through the induction element. The variable current in the induction element results in a variable magnetic field. The variable magnetic field penetrates a susceptor suitably positioned relative to the induction element and generates eddy currents inside the susceptor. The susceptor has an electrical resistance to the eddy currents, and thus the flow of the eddy currents against this resistance causes the susceptor to be heated by Joule heating. If the susceptor comprises a ferromagnetic material such as iron, nickel, or cobalt, heat may also be generated by magnetic hysteresis losses within the susceptor, i.e., by the changing orientation of magnetic dipoles within the magnetic material as a result of alignment with the variable magnetic field. In induction heating, for example, compared to heating by conduction, heat is generated inside the susceptor, enabling rapid heating. Further, no physical contact is required between the induction heater and the susceptor, allowing for increased freedom in construction and application.

[0049] The induction heating assembly of exemplary device 100 comprises a susceptor construct 132 (referred to herein as the "susceptor"), a first inductor coil 124, and a second inductor coil 126. The first and second inductor coils 124, 126 are made of a conductive material. In this example, the first and second inductor coils 124, 126 are made of Litz wire / cable wound in a helical form to provide helical inductor coils 124, 126. Litz wire comprises a plurality of individual wires that are individually insulated and twisted together to form a single wire. Litz wire is designed to reduce skin effect losses within the conductor. In exemplary device 100, the first and second inductor coils 124, 126 are made of copper Litz wire having a rectangular cross-section. In other examples, the Litz wire may have other shaped cross-sections, such as circular.

[0050] The first inductor coil 124 is configured to generate a first alternating magnetic field for heating a first region of the susceptor 132, and the second inductor coil 126 is configured to generate a second alternating magnetic field for heating a second region of the susceptor 132. In this example, the first inductor coil 124 is adjacent to the second inductor coil 126 in a direction along the longitudinal axis 134 of the device 100 (i.e., the first and second inductor coils 124, 126 do not overlap). The susceptor structure 132 may comprise a single susceptor or two or more separate susceptors. The ends 130 of the first and second inductor coils 124, 126 may be connected to the PCB 122.

[0051] It should be understood that the first and second inductor coils 124, 126 may have at least one characteristic that is different from each other in some examples. For example, the first inductor coil 124 may have at least one characteristic that is different from the second inductor coil 126. More specifically, in one example, the first inductor coil 124 may have an inductance value that is different from the second inductor coil 126. In FIG. 2, the first and second inductor coils 124, 126 are of different lengths such that the first inductor coil 124 is wound over a smaller region of the susceptor 132 than the second inductor coil 126. Thus, the first inductor coil 124 may have a different number of turns than the second inductor coil 126 (assuming that the spacing between individual turns is substantially the same). In yet another example, the first inductor coil 124 may be made of a different material than the second inductor coil 126. In some examples, the first and second inductor coils 124, 126 may be substantially identical.

[0052] In this example, the first inductor coil 124 and the second inductor coil 126 are wound in opposite directions. This can be useful when the inductor coils are active at different times. For example, initially, the first inductor coil 124 may operate to heat a first region of the article 110, and later, the second inductor coil 126 may operate to heat a second region of the article 110. Winding the coils in opposite directions helps reduce the current induced in the induction coils when used in conjunction with a particular type of control circuit. In FIG. 2, the first inductor coil 124 is a right-handed helix, and the second inductor coil 126 is a left-handed helix. However, in another embodiment, the inductor coils 124, 126 may be wound in the same direction, or the first inductor coil 124 may be a left-handed helix, and the second inductor coil 126 may be a right-handed helix.

[0053] The susceptor 132 of this example is hollow and thus defines a receptacle for receiving the aerosol-generating material. For example, the article 110 may be inserted into the susceptor 132. In this example, the susceptor 120 is tubular with a circular cross-section.

[0054] The device 100 of FIG. 2 is generally tubular and further includes an insulating member 128 that at least partially surrounds the susceptor 132. The insulating member 128 can be constructed from any insulating material such as, for example, plastic. In this particular example, the insulating member is constructed from polyetheretherketone (PEEK). The insulating member 128 can help insulate the various components of the device 100 from the heat generated within the susceptor 132.

[0055] The insulating member 128 can also fully or partially support the first and second inductor coils 124, 126. For example, as shown in FIG. 2, the first and second inductor coils 124, 126 are positioned around the insulating member 128 and are in contact with the radially outward surface of the insulating member 128. In some examples, the insulating member 128 does not abut against the first and second inductor coils 124, 126. For example, a small gap may exist between the outer surface of the insulating member 128 and the inner surfaces of the first and second inductor coils 124, 126.

[0056] In certain examples, the susceptor 132, the insulating member 128, and the first and second inductor coils 124, 126 are coaxial about the central longitudinal axis of the susceptor 132.

[0057] FIG. 3 shows a side view of the device 100 in partial cross-section. In this example, an outer cover 102 is present. The rectangular cross-sectional shape of the first and second inductor coils 124, 126 can be more clearly visualized.

[0058] The device 100 further includes a support 136 that engages one end of the susceptor 132 to hold the susceptor 132 in place. The support 136 is connected to the second end member 116.

[0059] The device may also include a second printed circuit board 138 associated within the control element 112.

[0060] The device 100 further includes a second lid / cap 140 and a spring 142 disposed toward the distal end of the device 100. The spring 142 enables the second lid 140 to be opened to provide access to the susceptor 132. A user can open the second lid 140 to clean the susceptor 132 and / or the support 136.

[0061] Device 100 further includes an extension member 144 that extends away from the proximal end of susceptor 132 toward the opening 104 of the device. At least partially located within the extension member 144 is a retaining clip 146 that contacts and holds article 110 when received within device 100. The extension member 144 is connected to the end member 106.

[0062] FIG. 4 is an exploded perspective view of device 100 of FIG. 1 with outer cover 102 omitted.

[0063] FIG. 5A of FIG. 5 depicts a cross-section of a portion of device 100 of FIG. 1. FIG. 5B of FIG. 5 depicts an enlargement of a region of FIG. 5A. FIGS. 5A and 5B show article 110 received within susceptor 132, and article 110 is sized such that the outer surface of article 110 abuts the inner surface of susceptor 132. This ensures that heating is most efficient. Article 110 of this example includes aerosol-generating material 110a. The aerosol-generating material 110a is positioned within susceptor 132. Article 110 may also include other components such as a filter, a wrapper, and / or a cooling structure.

[0064] FIG. 5B shows that the outer surface of susceptor 132 is spaced apart from the inner surfaces of inductor coils 124, 126 by a distance 150 measured in a direction perpendicular to the longitudinal axis 158 of susceptor 132. In one particular example, the distance 150 is about 3 mm to 4 mm, about 3 mm to 3.5 mm, or about 3.25 mm.

[0065] FIG. 5B further shows that the outer surface of insulating member 128 is spaced apart from the inner surfaces of inductor coils 124, 126 by a distance 152 measured in a direction perpendicular to the longitudinal axis 158 of susceptor 132. In one particular example, the distance 152 is about 0.05 mm. In another example, the distance 152 is substantially 0 mm such that inductor coils 124, 126 abut and touch insulating member 128.

[0066] In one example, susceptor 132 has a wall thickness 154 of from about 0.025 mm to 1 mm, or about 0.05 mm.

[0067] In one example, susceptor 132 has a length of from about 40 mm to 60 mm, from about 40 mm to 45 mm, or about 44.5 mm.

[0068] In one example, insulating member 128 has a wall thickness 156 of from about 0.25 mm to 2 mm, from 0.25 mm to 1 mm, or about 0.5 mm.

[0069] FIG. 6 depicts a portion of the heating assembly of device 100. As briefly described above, the heating assembly includes a first inductor coil 124 and a second inductor coil 126 that are arranged adjacent to each other in a direction along axis 200. Inductor coils 124, 126 extend helically around insulating member 128. Susceptor 132 is disposed within tubular insulating member 128. In this example, the wires forming the first and second inductor coils have a circular cross-section, although they may have a different shaped cross-section such as a rectangular cross-section.

[0070] Axis 200 can be defined, for example, by one or both of inductor coils 124, 126. Axis 200 is parallel to the longitudinal axis 134 of device 100 and parallel to the longitudinal axis of susceptor 158. Each inductor coil 124, 126 thus extends around axis 200. Alternatively, axis 200 can be defined by insulating member 128 of susceptor 132.

[0071] In use, the first inductor coil 124 is operated first. This heats a first region of the susceptor 132 (i.e., the region of the susceptor 132 surrounded by the first inductor coil 124), which in turn heats a first portion of the aerosol-generating material. Subsequently, the first inductor coil 124 can be switched off and the second inductor coil 126 can be operated. This heats a second region of the susceptor 132 (i.e., the region of the susceptor 132 surrounded by the second inductor coil 126), which in turn heats a second portion of the aerosol-generating material. The second inductor coil 126 can be switched on while the first inductor coil 124 is operating, and the first inductor coil 124 can be switched off while the second inductor coil 126 continues to operate. Alternatively, the first inductor coil 124 can be switched off before the second inductor coil 126 is switched on. The controller can control when each inductor coil is operated / excited.

[0072] In some examples, the length 202 of the first inductor coil 124 is shorter than the length 204 of the second inductor coil 126. The length of each inductor coil is measured in a direction parallel to the axis 200 of the inductor coils 124, 126. The first, shorter inductor coil 124 can be disposed closer to the mouth-side end (proximal end) of the device 100 than the second inductor coil 126. When the aerosol-generating material is heated, an aerosol is released. When the user inhales, the aerosol is drawn towards the mouth-side end of the device 100 in the direction of arrow 206. The aerosol exits the device 100 through the opening / mouthpiece 104 and is inhaled by the user. The first inductor coil 124 is disposed closer to the opening 104 than the second inductor coil 126.

[0073] In this example, the first inductor coil 124 has a length 202 of about 20 mm, and the second inductor coil 126 has a length 204 of about 30 mm. The first wire wound in a helical shape to form the first inductor coil 124 has a length of about 285 mm when not wound. The second wire wound in a helical shape to form the second inductor coil 126 has a length of about 420 mm when not wound.

[0074] Each inductor coil 124, 126 is formed from a Litz wire comprising a plurality of wire strands. For example, there may be from about 50 to about 150 wire strands within each Litz wire. In this example, there are about 75 wire strands within each Litz wire. In some examples, the wire strands are grouped into two or more bundles, each bundle comprising several wire strands, such that the total number of wire strands when summing all wire strands within all bundles results in the total number of wire strands. In this example, there are 5 bundles of 15 wire strands.

[0075] Each of the wire strands has a certain diameter. For example, the diameter may be from about 0.05 mm to about 0.2 mm. In some examples, the diameter is from 34 AWG (0.16 mm) to 40 AWG (0.0799 mm), where AWG is the American Wire Gauge standard. In this example, each of the wire strands has a diameter of 38 AWG (0.101 mm). Thus, the Litz wire may have a radius of from about 1 mm to about 2 mm. In this example, the Litz wire has a radius of from about 1.3 mm to about 1.4 mm.

[0076] As shown in FIG. 6, the Litz wire of the first inductor coil 124 is wound about 6.75 times around the axis 202, and the Litz wire of the second inductor coil 126 is wound about 8.75 times around the axis 202. The Litz wire does not form a complete number of turns (see, e.g., FIG. 10) because some ends of the Litz wire are bent away from the surface of the insulating member 128 before a complete turn is completed.

[0077] Figure 6 shows the gaps between successive windings / wraps. These gaps may be, for example, from about 0.5 mm to about 2 mm.

[0078] In some examples, each inductor coil 124, 126 has the same pitch, which is the length of the inductor coil over one complete winding (measured along the axis 200 of the inductor coil or along the longitudinal axis 158 of the susceptor). In other examples, each inductor coil 124, 126 has a different pitch.

[0079] In this example, the first inductor coil 124 has a mass of about 1.4 g and the second inductor coil 126 has a mass of about 2.1 g.

[0080] In one example, the inner diameter of the first and second inductor coils 124, 224, 224, 226 is about 12 mm in length and the outer diameter is about 14.3 mm in length.

[0081] Figure 7 depicts a flowchart of a method 300 for forming an aerosol supply device inductor coil. Such a method can be used to form one or both of the inductor coils 124, 126 described in connection with FIGS. 2 - 6.

[0082] The method includes, at block 302, providing a litz wire comprising a plurality of wire strands, each of the plurality of wire strands comprising a joinable coating. For example, a litz wire having the parameters described above can be provided.

[0083] This method includes, at block 304, the step of forming an inductor coil from a litz wire on a support member, wherein the inductor coil has a predefined shape. FIG. 8 depicts an exemplary apparatus used to form an inductor coil 400 from a litz wire. As shown, the litz wire 402 may first be wound around a bobbin 404 before being unwound and wound around a support member 406. In this example, the drum 408 is rotated and moved parallel to the guide rail 410, thereby causing the litz wire to be helically wound along the length of the support member 406. The speed at which the drum 408 rotates and moves along the guide rail 410 defines the spacing / gap size between adjacent turns in the inductor coil 400. To form a longer inductor coil 400, the drum 408 can be moved further along the guide rail 410 (while continuing to rotate). To form an inductor coil 400 with a greater number of turns, the drum 408 can rotate a greater number of times.

[0084] The support member 406 has a diameter that substantially corresponds to the diameter of the insulating member 128. Accordingly, the support member 406 has an outer cross-section that corresponds to the outer cross-section of the insulating member 128. When the litz wire 402 is wound around the support member 406, an inductor coil 400 having a predefined shape is formed. Accordingly, the support member 406 at least partially defines the shape of the inductor coil 400. Accordingly, the inner cross-section of the inductor coil 400 is substantially the same as the outer cross-section of the support member 406. In this example, the support member 406 has a diameter of about 12 mm. The litz wire has a diameter of about 1.3 mm, and as a result, the outer diameter of the inductor coil is about 14.6 mm. Inductor coils having different dimensions can be formed in the same manner.

[0085] Once the inductor coil 400 is formed in the desired shape, the method further includes, at block 306, activating a joinable coating so that the inductor coil 400 substantially retains its predefined shape. In this example, the litz wire has an enamel joinable coating that is activated by heating. Thus, heat is applied to the inductor coil 400 while the inductor coil 400 remains on the support member 406. In this example, the heated air is moved through the inductor coil 400. For example, the air is heated to an activation temperature suitable for activating the joinable coating and blown across the inductor coil 400 by a fan or an air gun. In one example, the activation temperature is about 190 degrees Celsius. The heat activates the joinable coating, as a result of which the viscosity of the joinable coating decreases. After a predefined period, the application of heat is stopped and the joinable coating begins to cool. In some examples, the cooling process can be accelerated by the application of cold air. For example, an air gun or a fan can flow cold air / ambient air across the inductor coil. As the temperature of the joinable coating drops, the viscosity of the joinable coating increases again. This joins the individual wire strands within the litz wire to each other. In another example, the joinable coating can be activated by contact with a solvent.

[0086] After the joinable coating is activated, the method further includes, at block 308, removing the inductor coil from the support member 406. The joining process means that the inductor coil 400 substantially retains its predefined shape even after being removed from the support member 406. To facilitate removal from the support member, the support member can be formed of or coated with a material to which the inductor coil does not strongly adhere, such that the coil also does not join to the support during the heating process. The support member can be, for example, made of metal.

[0087] The litz wire stored in the bobbin 404 may have a specific twisting direction. That is, the individual strands of wire within the litz wire are twisted in a specific direction. For example, the wire strands may have a left-handed twist direction or a right-handed twist direction. The litz wire preferably has a twist direction corresponding to the winding direction of the litz wire around the support member 406. For example, a litz wire having a right-handed twist direction should be used for an inductor coil wound in a right-handed manner. A litz wire having a left-handed twist direction should be used for an inductor coil wound in a left-handed manner. This configuration has been found to prevent the wire strands from unwinding, meaning that the inductor coil more closely adapts to the outer surface of the insulating member 128.

[0088] Other shaped inductor coils may be formed in a substantially similar manner. For example, a flat inductor coil may be formed by winding a litz wire while being supported by a support member of a suitable shape.

[0089] Once the inductor coil 400 is formed and removed from the support member 406, the inductor coil 400 may be assembled within the device 100. Thus, the method may further include the step of receiving the inductor coil 400 on the insulating member 128. For example, the inductor coil 400 may be slid onto the insulating member 128. From there, the inductor coil 400 may be connected to a power source within the device 100.

[0090] FIG. 9 depicts first and second inductor coils 124, 126 connected to a printed circuit board (PCB) 122. The first inductor coil 124 includes a first connection portion 500a leading to a first end 130a of the first inductor coil 124. Thus, the first connection portion 500a includes the first end 130a. The connection portion 500a forms an electrical connection with the PCB 122 so that the inductor coil 124 can receive power. The first inductor coil 124 also includes a second connection portion 500b leading to a second end 130b of the first inductor coil 124. Thus, the second connection portion 500b includes the second end 130b. The second connection portion 500b also forms an electrical connection with the PCB 122. In some examples, any portion of the connection portions 500a, 500b may be electrically connected to the PCB 122 rather than the ends 130a, 130b.

[0091] Similarly, the second inductor coil 126 includes a first connection portion 500c leading to a first end 130c of the second inductor coil 126. Thus, the first connection portion 500c includes the first end 130c. The first connection portion 500c forms an electrical connection with the PCB 122 so that the inductor coil 126 can receive power. The second inductor coil 126 also includes a second connection portion 500d leading to a second end 130d of the second inductor coil 126. Thus, the second connection portion 500d includes the second end 130d. The second connection portion 500d also forms an electrical connection with the PCB 122. In some examples, any portion of the connection portions 500c, 500d may be electrically connected to the PCB 122 rather than the ends 130c, 130d.

[0092] Thus, each inductor coil 124, 126 includes connection portions disposed at each end. Generally, a connection portion is defined as the portion of the inductor coil that forms an electrical connection with a power source. More specifically, a connection portion includes an end of the inductor coil.

[0093] As shown in FIG. 9, each of the inductor coils 124, 126 has two connection portions, each of which is disposed at an end of the inductor coil. Therefore, the shape of the inductor coils 124, 126 is partially defined by the connection portions. FIG. 10 depicts a top view of the first and second inductor coils 124, 126 with the first inductor coil 124 located on top.

[0094] As shown, both connection portions of each of the inductor coils 124, 126 are in a substantially same plane 600. Thus, as shown in FIG. 9, the first and second ends of each of the inductor coils 124, 126 are on / end on an axis 502 parallel to the axis 200 defined by the inductor coil. The plane 600 is arranged such that it is disposed tangentially with respect to the inductor coils 124, 126, and as a result, a 90-degree angle is defined between the plane 600 and the radius 602 of the inductor coil 124 at the point where the plane 602 forms a tangent with the inductor coil 124.

[0095] The method desirably includes, in block 304, the step of bending at least one of the connection portions such that it is in the same plane as the other connection portions. The dashed line in FIG. 10 depicts the second connection portion of the first inductor coil 124 before being bent to a predetermined position. In this initial position, the second connection portion 500b extends tangentially away from the helical portion of the inductor coil 124. To form the inductor coil 124, the connection portion 500b is bent by approximately 90 degrees such that the second end 130b is in the same plane as the first end 130a. The solid line in FIG. 10 shows the second connection portion 500b after being bent to the predetermined position. In this example, the first connection portion 500a is not bent and extends tangentially from the helical portion of the inductor coil 124. By forming the inductor coils 124, 126 in this manner, the ends of the inductor coils 124, 126 can be more easily connected by the PCB 122.

[0096] As described, the connection portion enables the inductive coil to be connected to a power source (e.g., via the PCB 122). To form a suitable electrical contact, the method further includes the step of immersing / dipping the connection portion in solder for a period of time. For example, the end of the inductive coil is immersed in solder. The molten solder acts to melt the insulator or separately remove the insulator from the plurality of wire strands within the litz cable, thus creating a point for good electrical contact.

[0097] In this example where the litz wire comprises approximately 75 individual wire strands having a diameter of 38 AWG (0.101 mm), the solder should be at a temperature of approximately 450°C and the connection portion should be immersed in the solder for approximately 4 - 5 seconds to ensure that good electrical contact is created. Once the connection portion is formed, the inductive coil can be connected to a power source (such as the PCB 122).

[0098] The above embodiments are to be understood as illustrative examples of the present invention. Further embodiments of the present invention will occur to one of ordinary skill in the art. Any feature described in connection with any one embodiment may be used alone or in combination with any other feature described, and may also be used in combination with one or more features of any other embodiment, or any combination of any other embodiments. It is further understood that equivalents and modifications not described above may be employed without departing from the scope of the invention as defined in the appended claims.

[0099] This specification discloses the following embodiments. (Embodiment 1) A method of forming an aerosol supply device inductive coil, comprising: providing a litz wire comprising a plurality of wire strands, each of the plurality of wire strands having a coating that is joinable; Forming an inductor coil from the Litz wire on a support member, the inductor coil having a predetermined shape; Activating the joinable coating so that the inductor coil substantially retains the predetermined shape; Removing the inductor coil from the support member. A method comprising the steps of. (Embodiment 2) The method according to embodiment 1, wherein the step of forming the inductor coil includes winding the Litz wire around the support member to form a helical inductor coil. (Embodiment 3) The predetermined shape includes a connection portion for connecting the inductor coil to a power source at one or more ends of the inductor coil, and the method includes: The method according to embodiment 1 or 2, including the step of immersing the connection portion in solder for a period of time. (Embodiment 4) The method according to embodiment 3, wherein the period is about 2 seconds to about 6 seconds. (Embodiment 5) The method according to embodiment 3 or 4, wherein the solder has a temperature of about 400°C to about 500°C. (Embodiment 6) The method according to any one of embodiments 1 to 5, wherein the step of activating the joinable coating includes heating the joinable coating. (Embodiment 7) The method according to embodiment 6, including the step of cooling the inductor coil after activating the joinable coating. (Embodiment 8) The predetermined shape includes two connection portions, both of which are in substantially the same plane, and the forming step includes bending at least one of the connection portions so that it is in the plane. The method according to any one of embodiments 1 to 7. (Embodiment 9) The method according to embodiment 8, wherein the bending includes bending by about 90 degrees. (Embodiment 10) The method according to any one of embodiments 1 to 9, wherein the step of winding the litz wire includes winding the litz wire around the support member about 5 to 9 times. (Embodiment 11) The method according to any one of embodiments 1 to 10, wherein the litz wire has a twisting direction, and the forming step includes winding the litz wire in the same direction as the twisting direction. (Embodiment 12) The method according to any one of embodiments 1 to 11, wherein the joinable coating includes enamel. (Embodiment 13) An aerosol supply device induction coil formed from a litz wire including a plurality of wire strands, each of the wire strands having a joinable coating, the joinable coating being activated such that the aerosol supply device induction coil substantially retains its own shape without a support member. (Embodiment 14) The aerosol supply device induction coil according to embodiment 13, wherein the induction coil has a connection portion at one end, and the connection portion is coated with solder in electrical contact with substantially all of the wire strands of the litz wire. (Embodiment 15) An aerosol supply device according to embodiment 13 or 14, and An article comprising an aerosol generating material and An aerosol supply system comprising the same.

Claims

1. An aerosol supply device inductor coil (400) formed from a litz wire (402) comprising a plurality of wire strands, wherein the litz wire (402) has a twisting direction, the twisting direction being the direction in which the plurality of wire strands are twisted, and the litz wire (402) is wound in the same direction as the twisting direction to form the inductor coil (400).

2. The aerosol supply device inductor coil (400) according to claim 1, wherein the litz wire (402) forming the inductor coil (400) has first and second ends, and the first end comprises a first connection portion.

3. The aerosol supply device inductor coil (400) according to claim 2, wherein the second end of the litz wire (402) comprises a second connection portion.

4. The aerosol supply device inductor coil (400) according to claim 3, wherein the first and second connection portions are in substantially the same plane.

5. The aerosol supply device inductor coil (400) according to any one of claims 2 to 4, wherein one or both of the first and second connection portions contain solder, the solder covering substantially all of the wire strands of the litz wire and being in electrical contact with substantially all of the wire strands of the litz wire.

6. The aerosol supply device inductor coil (400) according to any one of claims 1 to 5, wherein the litz wire (402) comprises 50 to 150 wire strands.

7. The aerosol supply device inductor coil (400) according to claim 6, wherein the litz wire (402) comprises 75 wire strands.

8. The aerosol supply device inductor coil (400) according to any one of claims 1 to 7, wherein the wire strands are grouped into two or more bundles, each bundle comprising several wire strands, such that the total number of wire strands is obtained by summing the wire strands within all the bundles.

9. The aerosol supply device inductor coil (400) according to any one of claims 1 to 8, wherein the diameter of each wire strand is from 0.05 mm to 0.2 mm.

10. The aerosol supply device inductor coil (400) according to claim 9, wherein the diameter of each wire strand is 38 US wire gauge standard (0.101 mm).

11. The aerosol supply device inductor coil (400) according to any one of claims 1 to 10, wherein each of the wire strands comprises a coatable coating.

12. The aerosol supply device inductor coil (400) according to claim 11, wherein the coatable coating is activated.

13. The aerosol supply device inductor coil (400) according to any one of claims 1 to 12, wherein the inductor coil (400) comprises a gap between consecutive turns of the inductor coil (400), and each gap can have a length of 0.9 mm or 1 mm.

14. An aerosol supply device (100) comprising at least one aerosol supply device inductor coil (400) according to any one of claims 1 to 13.

15. An aerosol supply system comprising the aerosol supply device (100) according to claim 14 and an article (110), wherein the article (110) comprises an aerosol-generating material.

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