Induction coil structure

Abstract

To provide an induction coil arrangement for use with an apparatus for heating smokable material to volatilize at least one component of the smokable material.SOLUTION: An induction coil arrangement 1 comprises a board, panel or plate 10, and two flat spiral coils of electrically conductive material, such as copper. Specifically, the arrangement includes a plate 10 having opposite first and second sides 11, 12, a first flat spiral coil 21 of electrically conductive material mounted on the first side of the plate, and a second flat spiral coil of electrically conductive material mounted on the second side of the plate.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a device for heating smokable material to volatilize at least one component of the smokable material, an induction coil arrangement for use in a device for heating smokable material to volatilize at least one component of the smokable material, and a system comprising an article containing smokable material and a device for heating smokable material to volatilize at least one component of the smokable material. [Background technology]

[0002] Smoking articles such as cigarettes, cigars and the like, burn tobacco to produce tobacco smoke when used. Attempts have been made to provide alternatives to these articles by creating products that release compounds without combustion. Examples of such products are so-called "heat-not-burn" products or tobacco heating devices or products that release compounds by heating a material rather than burning it. The material can be, for example, tobacco or other non-tobacco products that may or may not contain nicotine. Summary of the Invention

[0003] A first aspect of the present invention provides an induction coil arrangement for use in an apparatus for heating smokable material to volatilize at least one component of the smokable material, the induction coil arrangement comprising: a plate having a first surface and a second surface facing in opposite directions; a first flat spiral coil of conductive material disposed on a first surface of the plate; a second flat spiral coil of conductive material disposed on a second surface of the plate; and The present invention provides an induction coil arrangement comprising:

[0004] In one exemplary embodiment, the induction coil arrangement includes a conductive connector electrically connecting the first flat spiral coil to the second flat spiral coil, in one exemplary embodiment, the conductive connector extends from a radially inner end of the first flat spiral coil to a radially inner end of the second flat spiral coil.

[0005] In one exemplary embodiment, when viewed from one side of the induction coil arrangement, the first flat spiral coil follows a clockwise path from the radially inner end of the first flat spiral coil and the second flat spiral coil follows a counterclockwise path from the radially inner end of the second flat spiral coil.

[0006] In one exemplary embodiment, the induction coil arrangement comprises a laminate having a first layer including a first flat spiral coil and a second layer including a second flat spiral coil. The first and second layers may be separated, such as by an intermediate layer of the laminate. When an intermediate layer is provided, the intermediate layer should be electrically insulating. In one exemplary embodiment, the laminate is or includes a printed circuit board.

[0007] In one exemplary embodiment, each of the first and second flat spiral coils is a rectangular coil, such as a square coil, hi another exemplary embodiment, each of the first and second flat spiral coils is a circular coil.

[0008] In one exemplary embodiment, the first and second flat spiral coils are axially aligned with one another.

[0009] In one exemplary embodiment, the plate is flat or substantially flat.

[0010] A second aspect of the present invention provides a structure comprising a plurality of induction coil arrangements according to the first aspect of the invention and a holder to which corresponding plates of the induction coil arrangements are connected to fix the induction coil arrangements in position relative to each other.

[0011] In one exemplary embodiment, the holder includes or houses a controller for controlling the operation of the flat spiral coils, hi one exemplary embodiment, the controller is for controlling the operation of at least one of the flat spiral coils independently from at least one other of the flat spiral coils.

[0012] A third aspect of the present invention provides an apparatus for heating smokable material to volatilize at least one component of the smokable material, the apparatus comprising an induction coil arrangement according to the first aspect of the invention or a structure according to the second aspect of the invention.

[0013] In one exemplary embodiment, the device is a tobacco heating product.

[0014] A fourth aspect of the present invention provides an apparatus for heating a smoking material to volatilize at least one component of the smoking material, comprising: a heating zone for receiving one or more articles including smoking material; a magnetic field generator for generating a varying magnetic field which, in use, penetrates a corresponding longitudinal portion of the heating zone; wherein the magnetic field generator includes a plurality of flat spiral coils of conductive material, the spiral coils being arranged successively along the longitudinal axis of the heating zone and in respective corresponding planes.

[0015] In one exemplary embodiment, the planes are parallel or substantially parallel to one another.

[0016] In one exemplary embodiment, the heating zone extends through an internal bore of each of a plurality of flat spiral coils.

[0017] In one exemplary embodiment, the device has a support, such as an elongated support, for supporting articles including smoking material within the bores in the flat spiral coil. In one exemplary embodiment, the support is tubular and surrounds the heating zone. In other embodiments, the support is non-tubular.

[0018] In one exemplary embodiment, the apparatus has a heating element including a heating material that is heatable by one or more penetrations of a fluctuating magnetic field to heat a heating zone, in one exemplary embodiment, the support is or includes a heating element.

[0019] In one exemplary embodiment, the heating material includes one or more materials selected from the group consisting of an electrically conductive material, a magnetic material, and a magnetically conductive material.

[0020] In one exemplary embodiment, the heating material comprises a metal or metal alloy.

[0021] In one exemplary embodiment, the heating material comprises one or more materials selected from the group consisting of aluminum, gold, iron, nickel, cobalt, conductive carbon, graphite, plain carbon steel, stainless steel, ferritic stainless steel, steel, copper, and bronze.

[0022] In one exemplary embodiment, the apparatus includes a controller for controlling the operation of at least one of the planar spiral coils independently of at least one other of the planar spiral coils.

[0023] In an exemplary embodiment, the magnetic field generator comprises the induction coil arrangement of the first aspect of the invention, and thus the plurality of flat spiral coils of conductive material of the magnetic field generator comprises first and second flat spiral coils of conductive material of the induction coil arrangement.

[0024] In one exemplary embodiment, the magnetic field generator comprises a structure according to the second aspect of the invention.

[0025] In one exemplary embodiment, the device is for heating the smokable material to volatilize at least one component of the smokable material without combusting the smokable material.

[0026] In one exemplary embodiment, the device is a tobacco heating product.

[0027] A fifth aspect of the present invention provides a system for heating smokable material to volatilize at least one component of the smokable material, comprising: An apparatus according to the fourth aspect of the present invention; an article for placement within a heating zone of the device, the article comprising smoking material; The present invention provides a system comprising:

[0028] In one exemplary embodiment, the article is elongated.

[0029] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0030] [Figure 1] 1 shows a schematic perspective view of an example of an induction coil configuration for use in an apparatus for heating smokable material to volatilize at least one component of the smokable material; [Diagram 2] 2 shows a schematic cross-sectional view of the induction coil arrangement of FIG. 1. [Diagram 3] 2 shows a schematic perspective view of an example of a structure comprising a plurality of induction coil components of FIG. 1 and a holder to which the plates of each of the induction coil components are connected to fix the induction coil components in position relative to each other; [Figure 4] A schematic cross-sectional view of the structure of FIG. 3 is shown. [Diagram 5] A schematic cross-sectional view of an example of a system including an apparatus for heating smoking material to volatilize at least one component of the smoking material and an article containing smoking material for placement within the heating zone of the apparatus is shown. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] As used herein, the term "smoking material" includes materials that upon heating provide volatile components, typically in the form of a vapor or aerosol. "Smoking material" may be a non-tobacco-containing material or a tobacco-containing material. "Smoking material" may include, for example, one or more of tobacco itself, tobacco derivatives, expanded tobacco, reconstituted tobacco, tobacco extract, homogenized tobacco, or tobacco substitutes. Smoking material may be in the form of ground tobacco, cut rag tobacco, extruded tobacco, reconstituted tobacco, reconstituted smoking material, liquid, gel, gelled sheet, powder, or loaf, or the like. "Smoking material" may also include other non-tobacco products, which may or may not contain nicotine, depending on the product. "Smoking material" may include one or more humectants, such as glycerol or propylene glycol.

[0032] As used herein, the term "heater material" or "heating material" refers to a material that is heatable by the penetration of a changing magnetic field.

[0033] Induction heating is a process in which a conductive object is heated by penetrating a varying magnetic field into the object. The process is described by Faraday's law of induction and Ohm's law. An induction heater may comprise an electromagnet and a device for passing a varying current, such as an alternating current, through the electromagnet. When the electromagnet and the object to be heated are appropriately positioned relative to one another such that the resultant varying magnetic field generated by the electromagnet penetrates the object, one or more eddy currents are generated within the object. The object has a resistance to the flow of electric current. Thus, when such eddy currents are generated within the object, they flow against the electrical resistance of the object, thereby heating the object. This process is called Joule heating, Ohmic heating, or resistive heating. Objects that can be inductively heated are known as susceptors.

[0034] It has been found that when the susceptor is in the form of a closed electrical circuit, the magnetic coupling between the susceptor and the electromagnet in use is stronger, resulting in increased or improved Joule heating.

[0035] Magnetic hysteresis heating is the process of heating an object made of a magnetic material by the penetration of the object with a varying magnetic field. Magnetic materials can be thought of as containing many atomic-scale magnets, i.e., magnetic dipoles. When a magnetic field penetrates such a material, the magnetic dipoles align along the magnetic field. Thus, when a varying magnetic field, such as an alternating magnetic field, for example, as produced by an electromagnet, penetrates a magnetic material, the orientation of the magnetic dipoles changes in response to the varying applied magnetic field. This reorientation of the magnetic dipoles generates heat within the magnetic material.

[0036] When an object is both conductive and magnetic, the penetration of a changing magnetic field into the object can produce both Joule heating and magnetic hysteresis heating within the object. Furthermore, the use of magnetic materials can enhance the magnetic field, which can enhance Joule heating and magnetic hysteresis heating.

[0037] In each of the above processes, because heat is generated within the object itself, rather than by thermal conduction from an external heat source, rapid temperature rise and more uniform heat distribution within the object can be achieved, particularly through selection of suitable object materials and geometry, and suitable varying magnetic field magnitude and orientation relative to the object. Furthermore, induction heating and magnetic hysteresis heating do not require a physical connection between the source of the varying magnetic field and the object, allowing greater design freedom, better control over the heating profile, and lower costs.

[0038] 1 and 2, there are shown schematic perspective and cross-sectional views of an example of an induction coil arrangement according to an embodiment of the present invention. The induction coil arrangement 10 is for use in an apparatus for heating smokable material to volatilize at least one component of the smokable material, such as apparatus 100 shown in FIG. 5 and described below.

[0039] The induction coil arrangement 1 comprises a substrate, panel or plate 10 and two flat spiral coils of conductive material such as copper 21, 22. In use, a varying (e.g. alternating) current is passed through each of the coils 21, 22 to create a varying (e.g. alternating) magnetic field which penetrates the heating element and can be used to heat the heating element, as will be explained in more detail below.

[0040] The plate 10 has a first surface 11 and an opposite second surface 12. The first surface 11 and the second surface 12 of the plate 10 face away from each other. In this embodiment, the plate 10 is substantially flat, and the first and second surfaces 11, 12 are the main surfaces of the plate 10. The plate 10 should be made of a non-conductive material, such as a plastic material, to electrically insulate the coils 21, 22 from each other. In this embodiment, the plate 10 is made of FR-4, a composite material made of woven glass fiber cloth with an epoxy resin binder that is flame retardant. A first one 21 of the plurality of flat spiral coils of conductive material is disposed on the first surface 11 of the plate 10, and a second one 22 of the plurality of flat spiral coils of conductive material is disposed on the second surface 12 of the plate 10. Thus, the plate 10 is located between the coils 21, 22.

[0041] The coils 21, 22 may be attached to the plate 10 in any suitable manner. In this embodiment, the induction coil arrangement 1 is formed from a printed circuit board (PCB), and thus the first and second flat spiral coils 21, 22 are formed by printing a conductive material onto the respective first and second faces 11, 12 of the substrate or plate 10 during fabrication of the PCB, and then removing (such as by etching) selected portions of the conductive material such that a pattern of the conductive material in the form of the first and second flat spiral coils 21, 22 remains on the plate 10. Thus, the first and second flat spiral coils 21, 22 are a thin film or coating of conductive material on the plate 10.

[0042] Thus, the induction coil arrangement 1 of this embodiment comprises a laminate having a first layer (including a first flat spiral coil 21), a second layer (including a second flat spiral coil 22) and a third layer (plate 10) intermediate between the first and second layers. Thus, plate 10 separates the first and second layers. As plate 10 is made of a non-conductive material, coils 21, 22 are electrically insulated from each other (except for the conductive connector 30 described below). That is, coils 21, 22 are not in contact with each other. In other embodiments, coils 21, 22 may be electrically insulated from each other in a different manner, such as by an air gap between coils 21, 22. In some embodiments, coils 21, 22 may be preformed and then provided on plate 10 in any other suitable manner, such as by being attached to plate 10.

[0043] In some embodiments, plate 10 may be other than a layer of a PCB. For example, plate 10 may be a layer or sheet of material, such as a resin or adhesive, that has been dried, hardened, or solidified.

[0044] The use of coils made from thin printed conductive material as described above eliminates the need for Litz wire, which is made up of many strands of very thin wire gathered together in a braid to overcome the effect of reduced skin depth at higher excitation frequencies. Because the tracks on the PCB are thin (typically around 38um thick for 1Oz Cu and 76um thick for 2Oz Cu), their performance at high frequencies can be comparable to Litz wire of equivalent cross-section, yet without the problems associated with brittleness, shaping Litz wire, or connecting it to other components.

[0045] The first and second flat spiral coils 21, 22 are exposed on the plate 10, which helps to allow dissipation of any heat generated within the coils 21, 22 during use. However, in other embodiments, the first and second flat spiral coils 21, 22 may instead be embedded within the material forming the plate 10 to help protect the coils 21, 22 from damage during shipping, storage, and use.

[0046] In this embodiment, the induction coil arrangement 1 includes a conductive connector 30 that electrically connects the first flat spiral coil 21 to the second flat spiral coil 22. More specifically, the conductive connector 30 extends from the radially inner end 21a of the first flat spiral coil 21 to the radially inner end 22a of the second flat spiral coil 22, thereby connecting the coils 21, 22 in series. In this embodiment, the conductive connector 30 is formed as a "via" through the plate 10 of the PCB, in a manner that will be understood by those skilled in the art. In other embodiments, the conductive connector 30 may take different forms, such as a conductive lead or wire that is internal or external to the plate 10.

[0047] In this embodiment, the flat spiral coils 21, 22 are arranged in respective substantially parallel planes. That is, each of the flat spiral coils 21, 22 has a radius that is orthogonal (varying) to the plane in which the coils 21, 22 lie. Furthermore, the flat spiral coils 21, 22 are axially aligned with each other. That is, the imaginary point from which the path of one of the coils 21, 22 emanates lies on the same axis as the imaginary point from which the path of the other of the coils 21, 22 emanates, the axis being orthogonal to each of the respective planes in which the coils 21, 22 lie. Furthermore, in this embodiment, when observed from one side of the induction coil arrangement 1, the first flat spiral coil 21 follows a clockwise path from the radially inner end 21a of the first flat spiral coil 21, and the second flat spiral coil 22 follows a counterclockwise path from the radially inner end 22a of the second flat spiral coil 22. In this configuration, in use the magnetic fields generated by the coils 21, 22 reinforce each other, effectively doubling the inductance of the coils 21, 22 and doubling the magnetic field along the coil axis.

[0048] As shown in Figures 1 and 2, a hole 13 extends completely through the plate 10 from the first side 11 of the plate 10 to the second side 12 of the plate 10. Furthermore, each of the flat spiral coils 21, 22 is wound around a hole that is substantially aligned with the hole 13 through the plate 10. That is, there is a hole in the center of each of the flat spiral coils 21, 22. The hole 13 and each of the holes are through holes. In use, the varying magnetic field generated by the coils 21, 22 can be used to penetrate a heating element located within the hole 13 and / or within one or both of the holes, as will be explained in more detail below.

[0049] The thickness of each of the first and second flat spiral coils 21, 22, as measured from the first and second faces 11, 12 of the plate 10, may be greater than 50 micrometers and less than 200 micrometers, such as, for example, about 70 micrometers, about 100 micrometers, or about 140 micrometers. In other embodiments, one or each of the coils 21, 22 may have a thickness less than 50 micrometers or greater than 200 micrometers. The thickness selected will help determine the resistance of the coils 21, 22 and the extent to which the coils 21, 22 self-heat in use. The thickness of the plate 10, as measured between the first and second faces 11, 12 of the plate 10, may be less than 2 millimeters, such as, for example, less than 1 millimeter.

[0050] In principle, three or more flat spiral coils could be provided in each layer of the PCB, but because of thermal conduction, the outer layers of the PCB have 2-3 times greater current carrying capacity than any of the inner layers of the PCB. Thus, a dual coil structure such as that described above provides a balance between performance and complexity. Furthermore, in this embodiment, each of the coils 21, 22 is a round or circular flat spiral coil. In other embodiments, one or each of the coils 21, 22 could instead be a rectangular (e.g., square) flat spiral coil. A rectangular profile coil has a slightly higher inductance for a given profile, but circular coils can be more easily interleaved and / or components can be inserted between the coils, resulting in an overall increase in PCB area utilization. A rectangular profile also requires a longer line length for a given magnetic field strength along the coil axis. This increases resistance and reduces the Q factor compared to a circular coil of similar width.

[0051] In some embodiments, two or more of the above-mentioned induction coil configurations are provided as part of a structure that also includes a holder to which the induction coil configurations are connected or attached, which may hold the induction coil configurations in a fixed position relative to each other, relative to the holder, and / or relative to any other components secured to the holder.

[0052] For example, Figures 3 and 4 show schematic perspective and cross-sectional views of an example structure according to an embodiment of the invention. The structure 50 is for use in an apparatus for heating smokable material to volatilize at least one component of the smokable material, such as the apparatus 100 shown in Figure 5 and described below.

[0053] The structure 50 of this embodiment includes first to fifth induction coil components 1a, 1b, 1c, 1d, and 1e, each of which is identical to the induction coil component 1 shown in FIG. 1 and FIG. 2. The structure 50 further includes a holder 52 to which the plates 10 of the induction coil components 1a, 1b, 1c, 1d, and 1e are attached to fix the induction coil components 1a, 1b, 1c, 1d, and 1e in position relative to each other. In this embodiment, the holder 52 is 3D printed SLS (selective laser sintering) nylon. In other embodiments, the holder 2 may be formed in any other suitable manner, such as from a PCB or from any other suitable material. In this embodiment, the holder 52 includes a base 54, and the induction coil components 1a, 1b, 1c, 1d, and 1e extend away from the base 54 in a direction perpendicular or perpendicular to a surface of the base 54.

[0054] In this embodiment, induction coil components 1a, 1b, 1c, 1d, 1e are separate components from holder 52 and are assembled together with holder 52 during formation of structure 50. Each of induction coil components 1a, 1b, 1c, 1d, 1e includes an electrical connector 23 for electrically connecting coils 21, 22 to an electrical circuit while simultaneously securing induction coil components 1a, 1b, 1c, 1d, 1e to holder 52. In other embodiments, each of components 1a, 1b, 1c, 1d, 1e may include an electrical connector for connecting coils 21, 22 to an electrical circuit and one or more additional structural connector(s) for securing induction coil components 1a, 1b, 1c, 1d, 1e to holder 52. In yet a further variation of this embodiment, the holder 52 may be formed integrally with the plates 10 (and possibly also with the coils 21, 22) of the induction coil arrangements 1a, 1b, 1c, 1d, 1e.

[0055] As shown in Figures 3 and 4, the holder 52 holds the induction coil arrangements 1a, 1b, 1c, 1d, 1e relative to each other such that the flat spiral coils 21, 22 of the induction coil arrangements 1a, 1b, 1c, 1d, 1e are arranged in respective planes successively along the axis AA. In this embodiment, the flat spiral coils 21, 22 of the induction coil arrangements 1a, 1b, 1c, 1d, 1e are each in respective substantially parallel planes perpendicular to the axis AA. Furthermore, the flat spiral coils 21, 22 are all axially aligned with each other, since the respective imaginary points from which the paths of the coils 21, 22 originate are all on a common axis, in this case the axis AA. In addition, the holes 13 through each plate 10 are all axially aligned with each other and are all on the same axis AA as the respective imaginary points from which the paths of the coils 21, 22 originate.

[0056] In this embodiment, the structure 50 includes a controller (not shown) for controlling the operation of the flat spiral coils 21, 22. The controller is housed in the holder 52 and includes an integrated circuit (IC), although in other embodiments the controller may take different forms. In some embodiments, the controller is for controlling the operation of at least one of the induction coil arrangements 1a, 1b, 1c, 1d, 1e independently of at least one other of the induction coil arrangements 1a, 1b, 1c, 1d, 1e. For example, the controller may supply power to the coils 21, 22 of each of the induction coil arrangements 1a, 1b, 1c, 1d, 1e independently of the coils 21, 22 of the other induction coil arrangements 1a, 1b, 1c, 1d, 1e. In some embodiments, the controller may supply power sequentially to the coils 21, 22 of each of the induction coil arrangements 1a, 1b, 1c, 1d, 1e. Alternatively, in at least one mode of operation the controller may be for controlling the operation of all of the induction coil arrangements 1a, 1b, 1c, 1d, 1e simultaneously.

[0057] The holder 52 further includes three arms 55, 56, 57 that extend away from the base 54 in a direction perpendicular or orthogonal to the surface of the base 54 and substantially parallel to the induction coil configurations 1a, 1b, 1c, 1d, 1e. In this embodiment, the arms 55, 56, 57 are 3D printed SLS (selective laser sintering) nylon and are integral with the base 52. In other embodiments, the arms 55, 56, 57 may be separate components that are integrally assembled with the base 54.

[0058] Each of the arms 55, 56, 57 has an opening 55a, 56a, 57a therethrough, with an annular washer or shim 55b, 56b, 57b disposed within each of the openings 55a, 56a, 57a. Each of the shims 55b, 56b, 57b is made from a dielectric or electrically insulating material, such as polyetheretherketone (PEEK) or glass. PEEK has a relatively high melting point compared to most other thermoplastics, making it highly resistant to thermal degradation. Each of the shims 55b, 56b, 57b defines a hole 55c, 56c, 57c therethrough. All of the holes 55c, 56c, 57c are on the same axis AA as the respective imaginary points from which the paths of the coils 21, 22 emanate.

[0059] The structure 50 further comprises an elongated support 130 for supporting an article containing smoking material in use. In this embodiment, the support 130 is tubular and has a longitudinal axis that is coaxial with the axis AA. In other embodiments, the support 130 may be non-tubular. The support 130 is held in place by shims 55b, 56b, 57b and extends through holes in the plurality of flat spiral coils 21, 22, through holes 55c, 56c, 57c in the shims 55b, 56b, 57b, through openings 55a, 56a, 57a in the arms 55, 56, 57, and through holes 13 in the plate 10. The shims 55b, 56b, 57b help prevent the elongated support 130 from contacting the induction coil arrangements 1a, 1b, 1c, 1d, 1e, and in particular the coils 21, 22.

[0060] In this embodiment, the support 130 comprises a heating material that is heatable by penetration of a fluctuating magnetic field to heat an interior volume of the support 130. More specifically, in use, the respective fluctuating magnetic fields generated by the coils 21, 22 penetrate the support 130. Thus, respective portions of the heating element 130 are heatable by penetration of the respective fluctuating magnetic fields. Thus, the support 130 acts as a heating element in use. The controller may be configured to cause heating of respective portions of the heating element 130 at different respective times, for different respective durations, and / or at different respective rates, for example.

[0061] In other embodiments, the support 130 may not include a heating material. For example, in some embodiments, the support 130 may be made of a non-conductive material, such as glass or a plastic material. In further embodiments, the support 130 may be omitted.

[0062] 5, there is shown a schematic cross-sectional view of an example of a system according to an embodiment of the present invention. The system 1000 comprises an article 70 including smokable material 72 and an apparatus 100 for heating the smokable material 72 to volatilize at least one component of the smokable material 72. In this embodiment, the smokable material 72 includes tobacco and the apparatus 100 is a tobacco heating product (also known in the art as a tobacco heating device or non-combustion heating device).

[0063] In this embodiment, the smoking material 72 is in the form of a rod, and the article 70 includes a cover 74 around the smoking material 72. The cover 74 surrounds the smoking material 72 and helps protect the smoking material 72 from damage during transportation and use of the article 70. In use, the cover 74 can also help direct air flow into and through the smoking material 72, and can help direct vapor or aerosol flow through and out of the smoking material 72. In this embodiment, the cover 74 includes a covering that is wrapped around the smoking material 72 such that the free ends of the covering overlap one another. The covering thus forms all, or a majority, of the outer periphery of the article 70. The covering may be formed from paper, reconstituted tobacco, aluminum, or the like. The cover 74 also includes an adhesive (not shown) that adheres the overlapping free ends of the covering to one another. The adhesive may include, for example, one or more of gum arabic, natural or synthetic resins, starch, and varnish. The adhesive helps prevent the overlapping free ends of the covering from separating. In other embodiments, the adhesive and / or cover 74 may be omitted. In still other embodiments, the article may take a different form than any of those discussed above.

[0064] Generally speaking, the device 100 comprises an elongated heating zone 110 for receiving an item 70 and a magnetic field generator 120 for generating a varying magnetic field that penetrates respective portions 110a, 110b, 110c, 110d, 110e of the heating zone 110 in use. In this embodiment, the heating zone 110 includes a recess for receiving the item 70. The item 70 can be inserted into the heating zone 110 by a user in any suitable manner, such as through a slot in a wall of the device 100 or by first moving a portion of the device 100, such as the mouthpiece, to access the heating zone 110. In other embodiments, the heating zone 110 may be other than a recess, such as a shelf, surface, or protrusion, and may require a mechanical fit with the item to cooperate with or receive the item. In this embodiment, the heating zone 110 is sized and shaped to accommodate the entire item 70. In other embodiments, the heating zone 110 may be dimensioned to receive only a portion of the item 70 in use.

[0065] The device 100 has an air inlet (not shown) that fluidly connects the heating zone 110 with the exterior of the device 100, and an outlet (not shown) for allowing volatilizable material to pass from the heating zone 110 to the exterior of the device 100 in use. A user can inhale volatile components of the smokable material 72 by drawing on the volatile components through the outlet. As volatile components are removed from the heating zone 110, air is drawn into the heating zone 110 through the air inlet of the device 100. A first end 111 of the heating zone 110 is closest to the outlet and a second end 112 of the heating zone 110 is closest to the air inlet.

[0066] The magnetic field generator 120 comprises a plurality of flat spiral coils 21-22 of conductive material arranged in respective planes successively along the longitudinal axis HH of the heating zone 110. More specifically, the magnetic field generator 120 of the device 100 comprises the structure 50 of Figs. 3 and 4, the plurality of flat spiral coils 21, 22 of the magnetic field generator 120 being respective pairs 21, 22 of coils of the induction coil arrangements 1a, 1b, 1c, 1d, 1e. The connectors 30 of the induction coil arrangements 1a, 1b, 1c, 1d, 1e are omitted from Fig. 5 for clarity. The induction coil arrangements 1a, 1b, 1c, 1d, 1e surround respective portions 110a, 110b, 110c, 110d, 110e of the heating zone 110. It will be understood that the planes in which the coils 21, 22 lie are substantially parallel to each other. Moreover, all of the planes are substantially perpendicular to the longitudinal axis HH of the heating zone 110, which extends through holes in each of the flat spiral coils 21,22.

[0067] The longitudinal axis of the support 130 is coaxial with the longitudinal axis HH of the heating zone 110. In other embodiments, the support 130 may be non-tubular and / or may only partially surround the heating zone 110. For example, the support may be an element or pin that penetrates the heating zone 110 such that it is surrounded by the heating zone 110.

[0068] In this embodiment, the apparatus 100 comprises a controller 6 for controlling the operation of the flat spiral coils 21, 22. The controller 6 may, for example, control the operation of one of the flat spiral coils 21, 22 independently of at least one other of the flat spiral coils 21, 22, thereby causing inductive heating of a respective portion of the heating element 130. In some embodiments, the controller 6 may sequentially supply power to the coils 21, 22 of each of the induction coil arrangements 1a, 1b, 1c, 1d, 1e.

[0069] Although not shown, the magnetic field generator 120 also includes a power source (not shown) and a user interface (not shown) for operation by a user of the controller 6. In this embodiment, the power source is a rechargeable battery. In other embodiments, the power source may be other than a rechargeable battery, such as a non-rechargeable battery, a capacitor, or a connection to a power grid.

[0070] The controller 6 is electrically connected between a power source and the coils 21, 22 of the induction coil arrangements 1a, 1b, 1c, 1d, 1e, and is communicatively connected to a user interface which may be located external to the device 100. The controller 6, in this embodiment, is operated by a user's manipulation of the user interface which may include push buttons, toggle switches, dials, a touch screen, or the like.

[0071] In this embodiment, the user's manipulation of the user interface causes the controller 6 to pass an alternating current through one or more of the coils 21, 22 of the induction coil arrangements 1a, 1b, 1c, 1d, 1e, thereby generating an alternating magnetic field in the or each coil 21, 22. The coils 21, 22 and the heating element 130 are arranged relative to one another such that the alternating magnetic field generated by the coils 21, 22 penetrates the heating material of the heating element 130. When the heating material of the heating element 130 is a conductive material, this may result in the generation of one or more eddy currents in the heating material. The flow of eddy currents in the heating material against the electrical resistance of the heating material causes the heating material to heat by Joule heating. Furthermore, when the heating material is made of a magnetic material, the orientation of the magnetic dipoles in the heating material changes with the changing applied magnetic field, thereby generating heat in the heating material.

[0072] In this embodiment, the article 70 is elongate and has a longitudinal axis BB, which is coaxial or parallel to the longitudinal axis HH of the heating zone 110 when the article 70 is placed within the heating zone 110 in use. Thus, heating one of the more portions of the heating element 130 heats one or more of the corresponding portions 110a, 110b, 110c, 110d, 110e of the heating zone 110. This in turn heats one or more of the more corresponding sections 72a, 72b, 72c, 72d, 72e of the smokable material 72 of the article 70 when the article 70 is placed within the heating zone 110.

[0073] In some embodiments, the controller 6 is operable to heat a first section of the smokable material 72 prior to heating a second section of the smokable material 72. That is, the controller 6 is operable to apply a varying current to one or both of the coils 21, 22 of a first one of the induction coil configurations 1 to initiate volatilization of at least one component of, and generation of aerosol within, a first section of the smokable material 72 adjacent to the first induction coil configuration before applying a varying current to one or both of the coils 21, 22 of a second one of the induction coil configurations 1 to initiate volatilization of at least one component of, and generation of aerosol within, a second section of the smokable material 72 adjacent to the second induction coil configuration 1. Thus, gradual heating of the smokable material 72 of the article 70 may be effected over time.

[0074] In some embodiments, the first induction coil arrangement 1 and associated first section of smokable material 72 may be the one 1a, 72a closest to the first end 111 of the heating zone 110, and the second induction coil arrangement 1 and associated second section of smokable material 72 may be closer to the second end 112 of the heating zone 110. This helps to allow aerosol to be generated relatively quickly and emitted from the article 70 for inhalation by the user in the first section 72a of smokable material 72 that is relatively closer to the outlet, yet provides a time-dependent release of aerosol such that aerosol continues to be generated and emitted even after the first section 72a of smokable material 72 has stopped generating aerosol. Such cessation of aerosol generation may occur as a result of the first section 72a of smokable material 72 being depleted of volatile components.

[0075] The device 100 may include a temperature sensor (not shown) for sensing the temperature of the heating zone 110, or the temperature of the article 70, or the temperature of the heating element 130. The temperature sensor may be communicatively connected to the controller 6 so that the controller 6 can monitor the temperature. Based on one or more signals received from the temperature sensor, the controller 6 may adjust the characteristics of the fluctuating or alternating current passed through the coils 21, 22 as necessary to ensure that the temperature of the smokable material 72 remains within a predetermined temperature range, such as the amplitude, or the frequency, or the duty cycle, etc. Within the predetermined temperature range, in use, the smokable material 72 is heated sufficiently to volatilize at least one component 72 of the smokable material without combusting the smokable material 72. Thus, the controller 6, and the device 100 as a whole, are configured to heat the smokable material 72 to volatilize at least one component 72 of the smokable material without combusting the smokable material 72.

[0076] In some embodiments, the temperature range is from about 150° C. to about 300° C. The temperature range can be, for example, greater than 150° C., or greater than 200° C., or greater than 250° C. The temperature range can be, for example, less than 300° C., or less than 290° C., or less than 250° C. In some embodiments, the upper limit of the temperature range can be greater than 300° C. In some embodiments, the temperature sensor may be omitted.

[0077] In variations of this embodiment, the support 130 may be penetrable by less than all of the fluctuating magnetic field during use, and in some such variations, the unpenetrated portions of the support 130 may be heated by thermal conduction from the penetrated portions of the support 130 during use.

[0078] In other embodiments, the support and heating element of the device may be separate components. For example, the support may be a non-magnetic and / or non-conductive element and the heating element may be a rod or pin that penetrates the heating zone 110 such that it is surrounded by the heating zone 110. The support may be, for example, a tube of plastic material (such as PEEK) or glass that surrounds the heating zone 110. In some embodiments, the elongated support may be omitted.

[0079] In further embodiments, the article 70 may include at least one heating element including a heating material that is heatable by the intrusion of one or more of the fluctuating magnetic fields to heat the smokable material 72 of the article 70 in use. The heating element of the article 70 is in thermal contact, and in some embodiments, face-to-face contact, with the smokable material 72 of the article 70. For example, the heating element of such an article may be elongated and extend from a first end of the article to an opposite second end of the article. The heating element of the article may be, for example, tubular or rod-shaped. In some such embodiments, the smokable material may be tubular and may be radially inward or radially outward of the tubular heating element of the article. In some embodiments, the article 70 may include a heating material dispersed within the smokable material 72 of the article 70. For example, the article 70 may include a material including the smokable material 72 and a mixture of elements, each of which includes a heating material that is heatable by the intrusion of a fluctuating magnetic field. Each of the elements may include a closed circuit of the heating material. Some or each of the elements may be, for example, toroidal or spherical, and may be formed from multiple separate strands of heating material.

[0080] In some embodiments in which the article includes a heating element, the device 100 does not include a heating element that is penetrable by the magnetic field generated by the coils 21, 22. In other embodiments, the device 100 and the article 70 may each include a heating element. For example, in a variation of the embodiment shown in Figure 5, the article 70 may also include a tubular or rod-shaped heating element. Any of the above-described methods of operating the system 1000 shown in Figure 5 may be correspondingly used in such other embodiments.

[0081] In some embodiments, device 100 is sold, supplied, or otherwise provided separately from article 70 with which device 100 can be used. However, in some embodiments, device 100 and one or more of articles 70 may be provided together as a system, such as a kit or assembly, possibly with additional components, such as cleaning tools.

[0082] In each of the above-described embodiments, the article 70 is a consumable item. Once all, or substantially all, of the volatile components of the smokable material 72 within the article 70 has been depleted, the user may remove the article 70 from the heating zone 110 of the device 100 and discard the article 70. The user may then reuse the device 100 with another one of the articles 70. However, in other embodiments, the article may be non-consumable, with the device and article being discarded together once the volatile components of the smokable material have been depleted.

[0083] In each of the above-described embodiments, the heating material is steel. However, in other embodiments, the heating material may include one or more materials selected from the group consisting of conductive materials, magnetic materials, and magnetic conductive materials. In some embodiments, the heating material may include a metal or metal alloy. In some embodiments, the heating material may include one or more materials selected from the group consisting of aluminum, gold, iron, nickel, cobalt, conductive carbon, graphite, plain carbon steel, stainless steel, ferritic stainless steel, copper, and bronze. In other embodiments, other heating materials may be used. In some embodiments where the heating material includes iron, such as steel (e.g., mild steel or stainless steel), the heating element (such as support 130) may be coated to help avoid corrosion or oxidation of the heating element during use. Such coatings may include, for example, nickel plating, gold plating, or a ceramic or inert polymer coating.

[0084] In each of the above-described embodiments, the smoking material includes tobacco. However, in respective variations of each of these embodiments, the smoking material may consist of tobacco, consist substantially entirely of tobacco, include tobacco and smoking material other than tobacco, include smoking material other than tobacco, or be tobacco-free. In some embodiments, the smoking material may include a vapor or aerosol generating agent or a humectant, such as glycerol, propylene glycol, triacetin, or diethylene glycol.

[0085] To address various problems and advance the art, the entire disclosure illustrates, by way of example and illustration, various embodiments in which the claimed invention may be practiced and provides an improved induction coil arrangement for use in an apparatus for heating a smokable material to volatilize at least one component of the smokable material, an improved apparatus for heating a smokable material to volatilize at least one component of the smokable material, and an improved system including such an apparatus. The advantages and features of the disclosure are only a representative sample of embodiments and are not intended to be exhaustive and / or exclusive. The advantages and features of the disclosure are presented only to aid in the understanding and teaching of the claimed and otherwise disclosed features. It is to be understood that the advantages, embodiments, examples, features, features, structures, and / or other aspects of the disclosure should not be construed as limitations of the disclosure as defined by the claims, or of the equivalents of the claims, and that other embodiments may be utilized and changes may be made without departing from the scope and / or spirit of the disclosure. Various embodiments may comprise, consist of, or consist essentially of various combinations of the disclosed elements, components, features, parts, steps, means, etc. The present disclosure may include other inventions that are not currently claimed, but may be claimed in the future. [Item of invention] [Item 1] 1. An induction coil arrangement for use in an apparatus for heating a smokable material so as to volatilize at least one component of the smokable material, comprising: a plate having a first surface and a second surface facing in opposite directions; a first flat spiral coil of conductive material disposed on the first surface of the plate; a second flat spiral coil of conductive material disposed on the second surface of the plate; and 1. An induction coil arrangement comprising: [Item 2] Item 2. The induction coil configuration of item 1, comprising a conductive connector electrically connecting the first flat spiral coil to the second flat spiral coil. [Item 3] 3. The induction coil configuration of claim 2, wherein the conductive connector extends from a radially inner end of the first flat spiral coil to a radially inner end of the second flat spiral coil. [Item 4] 4. The induction coil configuration according to any one of items 1 to 3, wherein, when viewed from one side of the induction coil configuration, the first flat spiral coil follows a clockwise path from a radially inner end of the first flat spiral coil and the second flat spiral coil follows a counterclockwise path from a radially inner end of the second flat spiral coil. [Item 5] 5. The induction coil configuration according to any one of claims 1 to 4, comprising a laminate having a first layer including the first flat spiral coil and a second layer including the second flat spiral coil. [Item 6] A plurality of induction coil assemblies according to any one of items 1 to 5, a holder to which the corresponding plates of the induction coil arrangements are connected to fix the induction coil arrangements in position relative to one another; A structure comprising: [Item 7] An apparatus for heating a smokable material so as to volatilize at least one component of the smokable material, the apparatus comprising the induction coil arrangement according to any one of items 1 to 5, or the structure according to item 6. [Item 8] 1. An apparatus for heating a smokable material to volatilize at least one component of the smokable material, comprising: a heating zone for receiving one or more articles including smoking material; a magnetic field generator for generating a varying magnetic field which, in use, penetrates a corresponding longitudinal portion of said heating zone; wherein the magnetic field generator includes a plurality of flat spiral coils of conductive material, the spiral coils being arranged in succession along a longitudinal axis of the heating zone and in respective corresponding planes. [Item 9] 9. The apparatus of claim 8, wherein the planes are substantially parallel to each other. [Item 10] 10. The apparatus of claim 8 or 9, wherein the heating zone extends through an internal bore of each of the plurality of flat spiral coils. [Item 11] 11. The device according to claim 10, comprising an elongated support for supporting an article containing smoking material within the bore in the flat spiral coil. [Item 12] Item 12. The apparatus of item 11, wherein the support is tubular and surrounds the heating zone. [Item 13] 13. The apparatus according to any one of items 8 to 12, having a heating element comprising a heating material heatable by penetration of one or more of the fluctuating magnetic fields to heat the heating zone. [Item 14] 14. The apparatus according to claim 13, wherein the support comprises the heating element. [Item 15] 15. The apparatus of claim 13 or 14, wherein the heating material comprises one or more materials selected from the group consisting of conductive materials, magnetic materials, and magnetic conductive materials. [Item 16] 16. The apparatus of any one of items 13 to 15, wherein the heating material comprises a metal or a metal alloy. [Item 17] 17. The apparatus according to any one of items 13 to 16, wherein the heating material comprises one or more materials selected from the group consisting of aluminum, gold, iron, nickel, cobalt, conductive carbon, graphite, plain carbon steel, stainless steel, ferritic stainless steel, steel, copper, and bronze. [Item 18] Item 18. The apparatus of any one of items 8 to 17, comprising a controller for controlling operation of at least one of the flat spiral coils independently of at least one other of the flat spiral coils. [Item 19] 19. The apparatus according to any one of items 8 to 18, wherein the magnetic field generator comprises the structure according to item 6. [Item 20] 20. The device according to any one of items 7 to 19, wherein the device is a tobacco heating product. [Item 21] 1. A system for heating a smokable material to volatilize at least one component of the smokable material, comprising: An apparatus according to any one of items 8 to 20, an article for placement within the heating zone of the device, the article comprising smokable material; A system comprising:

Claims

1. 1. An induction coil arrangement for use in an apparatus for heating a smokable material so as to volatilize at least one component of the smokable material, comprising: a plate having opposing first and second surfaces, the plate comprising a printed circuit board (PCB); a first flat spiral coil of conductive material printed on the first surface of the plate; a second flat spiral coil of conductive material printed on the second surface of the plate; and 1. An induction coil arrangement comprising:

2. the first flat spiral coil and the second flat spiral coil 10. The induction coil configuration of claim 1, having: (i) a thickness of about 38 um with 1 Oz Cu; or (ii) a thickness of about 76 um with 2 Oz Cu.

3. 3. The induction coil arrangement of claim 1 or 2, comprising a conductive connector electrically connecting the first flat spiral coil to the second flat spiral coil.

4. 4. The induction coil configuration of claim 3, wherein the conductive connector extends from a radially inner end of the first planar spiral coil to a radially inner end of the second planar spiral coil.

5. 5. The induction coil arrangement of claim 1, wherein when viewed from one side of the induction coil arrangement, the first flat spiral coil follows a clockwise path from a radially inner end of the first flat spiral coil and the second flat spiral coil follows a counterclockwise path from a radially inner end of the second flat spiral coil.

6. 6. The induction coil arrangement of claim 1, comprising a stack having a first layer including the first flat spiral coil and a second layer including the second flat spiral coil.

7. A plurality of induction coil configurations according to any one of claims 1 to 5; a holder to which the corresponding plates of the induction coil arrangements are connected to fix the induction coil arrangements in position relative to one another; A structure comprising:

8. The structure of claim 7 , wherein the retainer is formed from a PCB.

9. An apparatus for heating smokable material so as to volatilize at least one component of the smokable material, the apparatus comprising an induction coil arrangement as claimed in any one of claims 1 to 6, or a structure as claimed in claim 7 or 8.

10. 1. An apparatus for heating a smokable material to volatilize at least one component of the smokable material, comprising: a heating zone for receiving one or more articles including smoking material; a magnetic field generator for generating a varying magnetic field which, in use, penetrates a corresponding longitudinal portion of said heating zone; wherein the magnetic field generator includes a plurality of flat spiral coils of conductive material, the spiral coils being arranged in succession along a longitudinal axis of the heating zone and in respective corresponding planes, and each of the plurality of flat spiral coils being mounted on a PCB.

11. The apparatus of claim 10 , wherein the planes are substantially parallel to one another.

12. 12. The apparatus of claim 10 or 11, wherein the heating zone extends through an internal bore of each of the plurality of flat spiral coils.

13. 13. The apparatus of claim 12, further comprising an elongate support for supporting an article including smoking material within the bore in the flat spiral coil.

14. The apparatus of claim 13 , wherein the support is tubular and surrounds the heating zone.

15. An apparatus according to any one of claims 10 to 14, comprising a heating element comprising a heating material heatable by penetration of one or more of the fluctuating magnetic fields to heat the heating zone.

16. 16. Apparatus according to claim 15 when dependent on claim 13 or 14, wherein the support comprises the heating element.

17. 17. The apparatus of claim 15 or 16, wherein the heating material comprises one or more materials selected from the group consisting of conductive materials, magnetic materials, and magnetic conductive materials.

18. The apparatus of any one of claims 15 to 17, wherein the heating material comprises a metal or metal alloy.

19. 19. The apparatus of any one of claims 15 to 18, wherein the heating material comprises one or more materials selected from the group consisting of aluminum, gold, iron, nickel, cobalt, conductive carbon, graphite, plain carbon steel, stainless steel, ferritic stainless steel, steel, copper, and bronze.

20. 20. Apparatus according to any one of claims 10 to 19, comprising a controller for controlling the operation of at least one of the flat spiral coils independently of at least one other of the flat spiral coils.

21. Apparatus according to any one of claims 10 to 20, wherein the magnetic field generator comprises a structure according to claim 7.

22. A device according to any one of claims 9 to 21, wherein the device is a tobacco heating product.

23. 1. A system for heating a smokable material to volatilize at least one component of the smokable material, comprising: An apparatus according to any one of claims 10 to 22, an article for placement within the heating zone of the device, the article comprising smokable material; A system comprising:

Images