Patent Description:
The present invention relates to a heating element for an aerosol generating device and to a method of generating an inhalable aerosol or vapor.

The use of aerosol generating systems and devices, also known as e-cigarettes, e-cigs (EC), electronic nicotine delivery systems (ENDS), electronic non-nicotine delivery systems (ENNDS), electronic smoking devices (ESDs), personal vaporizers (PV), inhalation devices, vapes, which can be used as an alternative to conventional smoking articles such as lit-end cigarettes, cigars, and pipes, is becoming increasingly popular and widespread. The most commonly used e-cigarettes are usually battery powered and use a resistance heating element to heat and atomize a liquid containing nicotine (also known as e-cigarette liquid, e-cig liquids, e-liquid, juice, vapor juice, smoke juice, e-juice, e-fluid, vape oil), to produce a condensation aerosol (often called vapor) which can be inhaled by a user.

These e-cigarettes are known in the art and on a general level they comprise a mouthpiece arranged in fluid communication with a cartridge, inserted in the mouthpiece or an e-cigarette body to which the mouthpiece is connectable. A heating element is further arranged in an airflow path between an outlet of an e-liquid chamber in the cartridge and the mouthpiece to allow vaporization of the e-liquid contained in the chamber into an aerosol. The heating element may be arranged in connection with the body of the e-cigarette or in the cartridge itself and is designed to be electrically connected in use to a power supply or source. Control circuits, sensors and/or switches may also be provided for an improved control of the e-cigarette and its power/heating management.

Various heating element arrangements are known from the prior art for such aerosol generating systems. Most commonly found heating elements comprise resistive elements such as metal wire coils, which heat upon electrical connection to up to <NUM> to generate an aerosol. These heating elements are cheap and easy to implement but do not allow proper control of the heating temperature of the e-liquid.

Beyond wire coils, more sophisticated resistive heating elements comprising laminar components have also been proposed in the prior art. <CIT> describes for example an elongated heating element formed by a resistive lamella extending longitudinally in a cartridge parallel to an airflow path of the cartridge.

<CIT> discloses a vaporizer device for vaporizing substances containing active and/or aroma materials, including a mouthpiece with a fluid inlet and a fluid outlet, and including: a heating device with a thermal resistor being a metallic foil or a thin sheet configured as a dual coil and/or sinuous line with two ends and dimensions of the cross-section of a cigarette or a small cigar.

<CIT> discloses a power supply section for an e-vapor device includes a power supply section housing including a power supply portion and a heater assembly portion. The power supply portion includes a power supply, and the heater assembly portion includes a heating element and a support.

<CIT> discloses an atomizer and an electronic cigarette. The atomizer includes: an atomizer cartridge; a liquid storage area arranged inside the atomizer cartridge; an electric heating element coiled spirally to form a plate-shape structure; and a first liquid guide cloth.

<CIT> discloses an atomization module of electronic cigarette, the module including: an end cover, a seal ring, a meshed heating disc, an e-liquid conducting cotton including a surface; and a support.

<CIT> discloses a split airflow system for an electrically heated smoking system for generating aerosol, the split airflow system having a downstream end comprises a first channel defining a first flow route and a second channel defining a second flow route.

Such elongated heating elements however present several weaknesses, such as a long form factor due to the length of the heating element needed to generate a sufficient amount of vapor/aerosol or a vapor/aerosol composed of larger droplets as condensation will occur along the elongated air path. Furthermore, it proves difficult to adjust the aerosol temperature along the air flow channel, for example to provide temperature gradients over the length of the heating element in orderto improve aerosol formation and/or reduce condensation and potential leakage from the cartridges/devices. All these limitations have an impact on the consumer satisfaction from a sensory perspective.

it is an aim of the present invention to improve the known aerosol generating devices, and in particular to provide an alternative solution for a heating element for such devices, which does not suffer the disadvantages of the prior art and offer improved heating control and performances for improved users' experience.

On a general level, the disclosure provides a plate-shaped, preferably disc-shaped heating element for an aerosol-generating device such as an e-cigarette or an aerosol-generating consumable article or the like, which is configured to allow gradient heating of a vaporizable material delivered from a vaporizable material reservoir to a heating surface of the heating element. The heating element is such that the heating surface is arranged in use substantially perpendicular to an air flow channel in the aerosol generating device or article, i.e. the larger surfaces of the plate-shaped heating element are positioned to block the air flow, and the air flow passes through an opening of the heating element, for example a central opening. The plate-shaped heating element is preferably configured to carry a mesh on at least one of its surfaces. The vaporizable material may wick from the reservoir to the heating surface of the plate-shaped heating element through the mesh material, for example by capillarity, and is then evaporated by the heat generated through the plate-shaped heating element. The mesh element may be attached to the plate-shaped heating element by means of crimping ears or other equivalent means such as clips. The plate-shaped element may preferably be realized as a C-shaped disc element, the extremities of which forming and/or bearing electrical contacts. A heat gradient may be achieved in radial direction of the C-shaped disc element, therewith enabling a selective evaporation of substance provided in the vaporizable material.

In embodiments, the present invention concerns a heating element for an aerosol generating device, the heating element comprising a heating body extending from a first end to a second end and provided with at least first and second electric contact parts wherein the heating body is plate-shaped and comprises an opening forming a substantially central airflow passage in the plate-shaped body. The heating element is configured to provide a heating gradient between an outer periphery of the plate-shaped body and the opening therein and the heating element further comprises a mesh material on at least one side of the plate-shaped body. A thickness of the plate-shaped body measured in a transversal cross-section thereof perpendicular to sides of the plate-shaped body is variable from the outer periphery of the plate to the opening, and gradually diminishes between the outer periphery and the opening.

The temperature is of the heating element is proportional to the current distribution. For example, the range may be fixed, for example from <NUM> to <NUM>, or the range may be based on the evaporation temperature of the vaporizable material as maximal temperature to avoid overheating the vaporizable material in contact with the mesh. For example, the range may start at <NUM> and go up to this evaporation temperature. Accordingly, a temperature gradient will be about <NUM> to <NUM>. Of course, other values may be possible depending on the conditions and the vaporizable material.

in embodiments the disc plate comprises means for holding the mesh material. Such means may for example be ears, lugs or clips etc. or a combination thereof.

in embodiments the plate-shaped body is a disc.

The thickness profile of the disc plate may diminish to reach a sharp end or a flat end.

in embodiments, a largest dimension of the opening of the heating element is at most equal to a width of the plate-shaped body, said width being measured from the outer periphery to an outer edge of the opening in a direction passing through the centre of the opening.

in embodiments the disc plate is made for example of metal material and the mesh material is made for example of sintered or non-sintered metal fiber material or other porous materials The disc plate material and mesh material must resist to typical temperatures used to vaporize e-liquid, i.e., should not deform. Materials for the disc plate should be conductive and have a resistance as appropriate for implementing the heating with the current source available according to the principles of the present invention. Typical non-limiting illustrative examples of materials are Nickel, Nichrome, Kanthal, Tungsten, stainless steel, and/or alloys of these materials.

In embodiments the invention concerns a consumable article for an aerosol generating device, the article comprising a reservoir for a vaporizable material, the reservoir having a material outlet, at least one heating element as defined in present invention to heat vaporizable material exiting the reservoir through the reservoir outlet to form an aerosol, and an airflow channel having an air inlet and an outlet for the aerosol generated through heating of the vaporizable material, wherein the heating element is arranged with respect to the reservoir outlet and airflow channel such that vaporizable material exiting through the reservoir outlet permeates through the mesh material towards the outer periphery of the plate-shaped body and the airflow channel passes through the opening in the plate-shaped body.

in embodiments the article comprises at least two heating elements arranged in series along a common longitudinal axis passing through the centre of each of the openings, wherein each plate-shaped body of said heating elements is configured to provide a different heating temperature.

in embodiments of the article each plate-shaped body has a different thickness and/or a different profile in the transversal cross-section.

in embodiments the said vaporizable material comprise e-liquid and/or wax and/or gel.

in embodiments the present invention concerns an aerosol generating device, such as an e-cigarette, comprising a heating element or an article as defined in the present invention. The device may be an e-cigarette for example.

in embodiments the present invention concerns a method of generating an inhalable aerosol or vapor, wherein an article or a device as defined in the present invention is provided and wherein the plate-shaped body of each heating element is heated to a predetermined temperature at the periphery of the opening so as to heat a vaporizable material provided to the heating elements to its vaporization temperature and form an inhalable aerosol.

in embodiments the predetermined temperature provided by the plate-shaped body of each heating element is a different temperature for each plate so that the temperature of the aerosol generated by heating of a vaporizable material provided to the heating elements and circulated inside the airflow path is adjustable.

The above and other objects, features and advantages of the present invention and the manner of realizing them will become more apparent, and the invention itself will best be understood from a study of the following description with reference to the attached drawings showing some preferred embodiments of the invention.

The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description given below, explain features of the invention.

in the present application, identical reference numerals are used, where possible, to designate identical elements that are common to the figures. Also, the drawings are simplified for illustration purposes and may not be depicted to scale.

in the following description, the principles the present invention will be detailed with reference to an e-cigarette, but they are not limited to this illustrative embodiment and applicable to other similar device which are suitable to use a consumable article with a vaporizable material.

The term vaporizable material is used to designate any material that is vaporizable at a temperature up to <NUM>, preferably up to <NUM>, for example aerosol generating liquid, gel, wax and the like.

in embodiments represented in <FIG> heating element for an aerosol-generating device or aerosol-generating consumable article, e.g. a cartomizer, comprises a plate-shaped heating body <NUM> extending from a first end 10a to a second end 10b and having a general C-shape body <NUM> as shown in <FIG>. The substantially circular shape of the body <NUM> as shown in <FIG> is only exemplary and other shapes (i.e. square or triangular) may be contemplated by a skilled person for the plate heating element <NUM> within the scope of the current invention. The body <NUM> comprises an opening <NUM> preferably placed at the center of the plate body. The body <NUM> further comprises contacts <NUM> and <NUM>, reference <NUM> illustrating a negative contact and reference <NUM> illustrating a positive contact. The electrical contacts <NUM>, <NUM> may be integral with the body <NUM> or may be attached and electrically connected to the body <NUM>, such as at the ends 10a, 10b of the body <NUM>. Alternatively, one contact <NUM> or <NUM> may be integral with the body <NUM> and the other contact <NUM> or <NUM> may be attached and electrically connected to the body <NUM>. Also, reference <NUM> may illustrate the positive contact and reference <NUM> the negative contact.

According to the invention, the heating element <NUM> is configured to allow heating of a vaporizable material with a gradient of temperature from an entry point of contact of the vaporizable material with the body <NUM> towards an outlet point of contact at the central opening's rim 11a. in <FIG>, such temperature gradient is schematically illustrated with the lowest temperature at the periphery of the disc plate which is also the entry point of the vaporizable material as marked in <FIG> and the hottest zone being around the opening <NUM> of the body <NUM>.

According to the invention, a mesh is placed at least on one side of the body <NUM> as illustrated in <FIG> and <FIG>. <FIG> illustrates embodiment of the body <NUM> in cross-section. According to these exemplary embodiments, the body <NUM> seen in a transversal cross section taken along a central symmetry axis Z-Z' passing through the centre of the opening <NUM> may present a different profile: for example in <FIG>, the profile has a constant thickness, and therefore does not fall within the scope of the invention. In <FIG>, a profile in compliance with the invention is shown whereby the thickness gradually diminishes between the outer periphery 10c of the body <NUM> and the opening <NUM> to reach a sharp end forming a rim 11a of said opening <NUM>. in <FIG>, another example in compliance with the invention is shown where the rim 11a is formed of a flat end and not a sharp one. Considering an angle α defined between a median plane M of the body <NUM> and a line parallel to the upper surface U or lower surface L of the disc intersecting the longitudinal axis Z-Z' at the centre of the opening <NUM>, the angle α will be in a range from about <NUM>° to about <NUM>°.

In all these embodiments, the transversal profile shape will have an effect on the heating time and the temperature gradient and said transversal profile shape may be adjusted to reach a desired effect, for example a heating time and/or temperature or performance.

<FIG> illustrates an example of a body <NUM> with a mesh <NUM> in a transversal cross-section not in accordance with the present invention. The body <NUM> of this figure corresponds to the embodiment of <FIG> for illustrative purposes and the body <NUM> may also be as illustrated in <FIG> or another body according to the present invention. The mesh <NUM> may be on one side of the body <NUM> or on both sides.

<FIG> illustrates a further embodiment of a heating element <NUM> not in accordance with the invention, whereby the mesh <NUM> is attached to the body <NUM> by means of fastening members. For example, such fastening members may comprise clips <NUM> as illustrated on the left side of the assembly of the body <NUM> and mesh <NUM>, or lugs or ears <NUM> of the body <NUM> as schematically illustrated on the right side of the assembly body <NUM> and mesh <NUM>. Lugs or ears <NUM> may be integrally formed with the heating plate-shaped body <NUM> and provide for example for crimping the mesh <NUM>. The fastening members may be placed on the outer periphery 10c the body <NUM> and/or may be placed in the opening <NUM>. in order to maintain the mesh <NUM> on the body <NUM>, one may use a plurality of fastening members, for example at least three clips <NUM> placed around the periphery of the body and/or around the periphery of the opening <NUM>. The same construction may be followed for ears <NUM>. Alternative fastening members may of course also be used or combined with those previously described to allow proper attachment of the mesh <NUM> to the body <NUM>.

<FIG> illustrates a top view of a body <NUM> with ears <NUM> on the outer periphery of the plate and ears <NUM> on the periphery of the opening <NUM>. in this example, four ears <NUM> and three ears <NUM> are illustrated but less than four/three or more than four/three may be used. Also, the numbers of ears <NUM> and <NUM> may be the same or different. The ears <NUM>, <NUM> may be replaced by clips <NUM>, or one may use a combination of clips <NUM> and ears <NUM>, <NUM>.

<FIG> illustrate top view and side cut view of a body <NUM> with a mesh <NUM> that is fixed by the ears <NUM>, <NUM>. The opening <NUM> is illustrated as being disc-shaped in <FIG> but it may have another shape as illustrated in other figures of the present application.

According to the present invention, the body material and mesh material are chosen to sustain typical heating temperatures of heating elements used to vaporize aerosol-generating materials such as e-liquid, i.e. should not deform or be damaged/transformed up to temperatures of <NUM> to <NUM>. Preferable materials for both the body <NUM> and mesh <NUM> may include metals, metal alloys, ceramics or combination therefrom. The heating body material may include a ceramic sintered material, such as alumina (AI203) and silicon nitride (S13N4), or printed circuit board or silicon rubber. It may alternatively comprise electrically resistive material among one or more of the following materials: semiconductors such as doped ceramics, electrically "conductive" ceramics (such as, for example, molybdenum disilicide), carbon, graphite, metals, metal alloys and composite materials made of a ceramic material and a metallic material. Such composite materials may comprise doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbides. Examples of suitable metals include titanium, zirconium, tantalum and metals from the platinum group. Examples of suitable metal alloys include stainless steel, nickel-, cobalt-, chromium-, aluminum- titanium-zirconium-, hafnium-, niobium-, molybdenum-, tantalum-, tungsten-, tin-, gallium-and manganese-alloys, and super-alloys based on nickel, iron, cobalt, stainless steel.

The mesh <NUM> may also be formed of similar metallic material or non-metallic materials such as fiber, glass, aluminum, ceramic, glass fiber wick, stainless steel mesh for example.

<FIG> illustrates an embodiment of a consumable article <NUM>, such as a cartomizer, not in accordance with the present invention. The article <NUM> comprises a vaporizable material reservoir <NUM> with an outlet <NUM> and a plurality of bodies <NUM> (in <FIG> five plate-shaped bodies <NUM>) as heating elements, an outlet <NUM> being provided for each body, the heating element being arranged with respect to the reservoir outlet forming an airflow channel <NUM> such that vaporizable material <NUM> exiting through the reservoir outlet <NUM> permeates through the mesh material towards the outer periphery of each plate-shaped body <NUM> and the airflow channel passes through the opening in the plate-shaped body <NUM>. Of course, it is possible to use less than five bodies <NUM>, that is a least one body <NUM> or more than five such bodies <NUM>. The bodies <NUM> are arranged preferably parallel to each other and are connected to common electrical contacts <NUM>, <NUM>. The alignment of openings <NUM> of the bodies <NUM> along a longitudinal axis Z-Z' of the cartomizer forms the airflow path <NUM> in which a vapor or aerosol <NUM> formed by heating of a vaporizable material provided to the bodies <NUM> from the vaporizable material reservoir <NUM> is directed into the mouthpiece <NUM> for inhalation by a user. The bodies <NUM> are fitted with mesh material <NUM> as illustrated in <FIG> and <FIG> for example, this construction extending to all configurations of bodies <NUM> in accordance with the principles of the present invention.

in <FIG>, an embodiment of a consumable article according to the present invention is shown. This embodiment is similar to the one of <FIG> but differs in the profile of the individual bodies <NUM>. As shown, they may have different profiles as illustrated in <FIG> for example. in this figure, the first body <NUM> on the proximal side (i.e. close to the mouthpiece <NUM>) has the profile illustrated in <FIG>, the second body going downwards has the profile illustrated in <FIG> and the three last bodies on the distal end have the profile illustrated in <FIG>. Of course, this is only an example and all bodies <NUM> may have the same profile or a different one. Also the width of the airflow path may be constant from the distal side of the consumable article (away from the mouthpiece) to the proximal side of the consumable article (close to the mouthpiece) or it may change, for example increase from the distal side to the proximal side, or it may decrease from the distal side to the proximal side. This may be dependent on the profile of the bodies <NUM> or may be independent.

In the embodiment of <FIG>, the different profiles of the bodies <NUM> may be used to manage the temperature around the openings <NUM> of each body <NUM> and therefore to vary the temperature along the airflow path.

This can be achieved by selecting and arranging the bodies <NUM> in the consumable article so that a heating temperature profile along the air flow path in the article can be controlled. For example, to avoid particles condensation, one can choose to increase the temperature along the air flow channel, the proximal bodies <NUM> increasing progressively the temperature.

Alternatively, if one wants to reduce the vapor temperature, the proximal bodies will have a lower temperature than the distal bodies. A higher temperature in the middle portion of the article is likewise foreseeable increasing the temperature in the bodies arranged in such middle portion of the article. Preferably the temperature towards the opening <NUM> of each body shall be close to the boiling point of the vaporizable material provided to said body in the article. Accordingly, due to the temperature gradient, the vaporizable material is gradually vaporized until reaching the central (inner) zone of the disk. However, by exceeding the boiling point around about +<NUM> to <NUM>, the inner region will warm up the vapor.

For example, the temperature may be constant along the airflow path, or the temperature may increase or decrease from the distal side to the proximal side. in such case, the temperature of each body may increase, respectively decrease, or several bodies may have the same temperature.

<FIG> schematically illustrates an embodiment of a vapor generating device according to the present invention. Generally, such a device <NUM> comprises a mouthpiece <NUM>, a consumable article <NUM>, such as a cartomizer (comprising a cartridge containing the vaporizable material <NUM>), a heating element and a power supply or source <NUM>. For example, such device may be an e-cigarette.

<FIG> illustrates in a block diagram the method of generating an inhalable aerosol or vapor with an article as defined herein is provided and wherein the plate-shaped body (<NUM>) of each heating element is heated to a predetermined temperature at the periphery of the opening (<NUM>) in such a way to heat a vaporizable material provided to the heating elements to its vaporisation temperature and form an inhalable aerosol. Different temperature for each plate can be set so that the temperature of the aerosol generated by heating of a vaporizable material provided to the heating elements and circulated inside the airflow path (<NUM>) is adjustable.

The present description is neither intended nor should it be construed as being representative of the full extent and scope of the present invention. The present invention is set forth in various levels of detail herein as well as in the attached drawings and in the detailed description of the invention and no limitation as to the scope of the present invention is intended by either the inclusion or non-inclusion of elements, components, etc..

Claim 1:
A heating element (<NUM>) for an aerosol generating device, the heating element comprising a heating body (<NUM>) extending from a first end (10a) to a second end (10b) and provided with at least first and second electric contact parts (<NUM>, <NUM>) wherein the heating body (<NUM>) is plate-shaped and comprises an opening (<NUM>) forming a substantially central airflow passage in the plate-shaped body (<NUM>); wherein the heating element is configured to provide a heating gradient between an outer periphery of the plate-shaped body (<NUM>) and the opening (<NUM>) therein;
wherein the heating element further comprises a mesh material (<NUM>) on at least one side of the plate-shaped body (<NUM>);
characterized in that a thickness of the plate-shaped body (<NUM>) measured in a transversal cross-section thereof perpendicular to sides of the plate-shaped body is variable from the outer periphery of the plate to the opening (<NUM>), and gradually diminishes between the outer periphery and the opening (<NUM>).