Automatic cutting aerosol generator

Abstract

The present invention relates to a heating assembly for an aerosol generating device. The heating assembly may comprise a first solder spot and a second solder spot. The heating assembly may further comprise a connection strip electrically connecting the first solder spot to the second solder spot. One of the first solder spot and the second solder spot may be configured as a soft solder spot having a melting temperature of 200°C to 300°C. The connection strip may be configured as a bimetallic strip. The present invention further relates to an aerosol generating device comprising the heating assembly.

Description

[Technical Field]

[0001] The present invention relates to a heating assembly for an aerosol generating device.The present invention further relates to an aerosol generating device comprising a heating assembly. [Background technology]

[0002] It is known to provide aerosol-generating devices for generating inhalable vapors. Such devices may heat an aerosol-forming substrate to a temperature at which one or more components of the aerosol-forming substrate volatilize without burning the aerosol-forming substrate. The aerosol-forming substrate may be provided in liquid form. The aerosol-forming substrate may be volatilized in a heating chamber of the aerosol-generating device. A heating assembly comprising a heating element may be disposed within or around the heating chamber to heat the aerosol-forming substrate.

[0003] The heating element may be configured as a resistive heating element. The heating element may be disposed adjacent to a wicking element configured to draw the aerosol-forming substrate from the liquid reservoir toward the heating element. When the liquid reservoir is depleted, no more aerosol-forming substrate is drawn toward the heating element. If the heating element still operates when there is no longer any liquid substrate in the wick, overheating may become an issue. Overheating of the wicking material may lead to the release of undesirable vapor.

[0004] It would be desirable to have a heating assembly for an aerosol generating device that has overheat protection. It would be desirable to have a heating assembly for an aerosol generating device that prevents unwanted vapor release due to overheating. It would be desirable to have a heating assembly for an aerosol generating device that has improved safety. It would be desirable to have a heating assembly for an aerosol generating device that has mechanical overheat protection. It would be desirable to have a heating assembly for an aerosol generating device that has automatic overheat protection. Summary of the Invention

[0005] According to one embodiment of the present invention, there is provided a heating assembly for an aerosol generating device. The heating assembly may include a first solder spot and a second solder spot. The heating assembly may further include a connecting strip electrically connecting the first solder spot to the second solder spot. One of the first solder spot and the second solder spot may be configured as a soft solder spot having a melting temperature of 200°C to 300°C. The connecting strip may be configured as a bimetallic strip.

[0006] According to one embodiment of the present invention, there is provided a heating assembly for an aerosol generating device. The heating assembly includes a first solder spot and a second solder spot. The heating assembly further includes a connecting strip electrically connecting the first solder spot to the second solder spot. One of the first solder spot and the second solder spot is configured as a soft solder spot having a melting temperature of 200°C to 300°C. The connecting strip is configured as a bimetallic strip.

[0007] The heating assembly according to the present invention has an automatic protection against overheating. If overheated, the soft solder spot acts synergistically with the bimetallic strip to disconnect the heating assembly. More specifically, if the operating temperature of the heating assembly exceeds a desired temperature, the soft solder spot melts. The melting of the soft solder spot leads to the connection strip connecting the soft solder spot being released from the soft solder spot. At the same time, the connection strip, configured as a bimetallic strip, bends away from the soft solder spot due to the temperature increase. The melting of the soft solder spot, together with the bending of the connection strip, results in an electrical disconnection. The electrical disconnection disables the function of the heating assembly, thereby creating an automatic overheating protection.

[0008] The term "soft solder spot" refers to a solder spot that has a relatively low melting temperature, illustratively a melting temperature below 300°C.

[0009] The melting temperature of the soft solder spots may be between 225°C and 275°C, preferably about 250°C.

[0010] This melting temperature is optimized to prevent overheating of the heating assembly. This temperature may be slightly higher than the operating temperature of the heating assembly. The soft solder spot may have a melting temperature higher than the operating temperature of the heating assembly.

[0011] The connecting strip may be arranged to freely span between the first solder spot and the second solder spot.

[0012] The spanning arrangement of the connection strips may enable the connection strips to bend apart when the temperature exceeds the operating temperature of the heating assembly. As described herein, in this case, the soft solder spot melts, which may release the portion of the connection strip connected to the soft solder spot. At the same time, the connection strip bends away from the soft solder spot due to the bimetallic material of the connection strip. Due to the spanning arrangement of the connection strip, the connection strip may then bend away from the soft solder spot, thereby electrically disconnecting it from the soft solder spot. The connection strip may then be connected only to the other solder spot that is not configured as a soft solder spot. This other solder spot may act as a hinge around which the connection strip rotates during the disconnection operation.

[0013] The connecting strip may be configured to be severed from the soft solder spot by bending away from the soft solder spot when the temperature of the connecting strip exceeds 300°C, preferably when the temperature of the connecting strip exceeds 275°C, and most preferably when the temperature of the connecting strip exceeds 250°C.

[0014] The melting temperature of the other solder spot that is not the soft solder spot may be 600°C to 900°C, preferably 650°C to 850°C, and most preferably 700°C to 800°C.

[0015] The solder spots are configured so that they do not melt during an overheating scenario. The solder spots are not melted and the connection strips bend firmly apart, thereby facilitating an electrical disconnection action. The connection strips are held securely in place even in an overheating scenario by the solder spots not being configured as soft solder spots.

[0016] The bimetallic strip may include an active layer and a passive layer.

[0017] The active layer may have a higher coefficient of thermal expansion than the passive layer. The active layer may face the heating assembly. The passive layer may face away from the heating assembly.

[0018] The bimetallic strip may include a layer of an alloy of Fe—Ni and a layer of one of Cu, Ni, Fe—Ni—Cr, Fe—Ni—Mn, and Mn—Ni—Cu.

[0019] The bimetallic strip may be configured so that its shape does not change during normal operating temperatures of the heating assembly.

[0020] As a result, no mechanical stress is induced between the first solder spot and the second solder spot during normal operating temperatures.

[0021] Typical operating temperatures for the heating assembly may be between 90°C and 250°C, preferably between 150°C and 245°C, and most preferably between 200°C and 240°C.

[0022] The soft solder spot may include one of Sn95Pb5, Pb, Pb75In25, and Pb68Sn32.

[0023] The soft solder spots may be comprised of one of Sn95Pb5, Pb, Pb75In25, and Pb68Sn32.

[0024] The other solder spot that is not the soft solder spot may comprise, and preferably consist of, silver.

[0025] The soft solder spot may be configured to melt and release the connection strip when the temperature of the soft solder spot exceeds 300°C, preferably when the temperature of the soft solder spot exceeds 275°C, and most preferably when the temperature of the soft solder spot exceeds 250°C.

[0026] The heating assembly may further include a third solder spot and a heating filament disposed in electrical connection between the third solder spot and one of the first solder spots of the second solder spot.

[0027] The heating function of the heating assembly may be achieved by a heating element. The electrical connection of the heating assembly may be a series connection between the heating element and the connecting strip. The heating assembly may include a first contact and a second contact. The first and second contacts may be configured to supply electrical energy from a power source of the aerosol generating device to the heating assembly. The first contact may be electrically connected to the third solder spot. The third solder spot may be configured as the first contact. The second contact may be electrically connected to one of the first solder spot and the second solder spot. This solder spot may be configured as the second contact. The other of the first solder spot and the second solder spot may be electrically disposed between the third solder spot and the solder spot connected to the second contact. Electrical energy may be supplied through the heating assembly via the first contact, then the third solder spot, then the heating filament, then one of the first solder spot and the second solder spot, then the connecting strip, then the other of the first solder spot and the second solder spot, and finally through the second contact.

[0028] The heating element may be disposed to electrically connect the third solder spot to one of the first solder spot and the second solder spot. The heating element may be in direct contact with the wicking element. The heating element may be printed on the wicking element. The heating element may be embedded within the wicking element. The heating element may be a single filament. The heating element may have an S-shape.

[0029] The present invention further relates to an aerosol generating device comprising a heating assembly as described herein.

[0030] The aerosol-generating device may further comprise a liquid reservoir containing the liquid aerosol-forming substrate, and a wicking element configured to wick the liquid aerosol-forming substrate from the liquid reservoir to the heating assembly.

[0031] The heating filament of the heating assembly may be configured to heat and vaporize the liquid aerosol-forming substrate.

[0032] One or more first solder spots may be soldered onto the wicking element, preferably by first electrical contact pads, the second solder spots may be soldered onto the wicking element, preferably by second electrical contact pads, and the third solder spots may be soldered onto the wicking element, preferably by third electrical contact pads. The first electrical contact pads may be configured as first contacts. The second electrical contact pads may be configured as second contacts.

[0033] The wicking element may be elongated. The wicking element may be plate-shaped. The wicking element may be rectangular. One or both of the heating filament and the connecting strip may be arranged parallel to the wicking element. One or more of the first, second, and third solder spots may be arranged on the wicking element. One or more of the first, second, and third solder spots may be arranged on the wicking element via an electrical contact pad. The first solder spot may be arranged on the wicking element via a first electrical contact pad. The second solder spot may be arranged on the wicking element via a second electrical contact pad. The third solder spot may be arranged on the wicking element via a third electrical contact pad.

[0034] The aerosol generating device may further comprise a power supply for supplying power to the heater assembly, and a controller for controlling the supply of electrical energy from the power supply to the heater assembly.

[0035] The aerosol generating device may comprise an electrical circuit. The electrical circuit may comprise a microprocessor, which may be a programmable microprocessor. The microprocessor may be part of the controller. The electrical circuit may comprise further electronic components. The electrical circuit may be configured to regulate the supply of power to the heating element. Power may be supplied to the heating element continuously following activation of the aerosol generating device, or may be supplied intermittently (e.g., with each puff). Power may be supplied to the heating element in the form of current pulses. The electrical circuit may be configured to monitor the electrical resistance of the heating element and may preferably be configured to control the supply of power to the heating element depending on the electrical resistance of the heating element.

[0036] The aerosol generating device may include a power source (typically a battery) within the body of the aerosol generating device. In one embodiment, the power source is a lithium-ion battery. Alternatively, the power source may be a nickel-metal hydride battery, a nickel-cadmium battery, or a lithium-based battery (e.g., a lithium-cobalt battery, a lithium iron phosphate battery, a lithium titanate battery, or a lithium polymer battery). Alternatively, the power source may be another form of charge storage device, such as a capacitor. The power source may require recharging and may have a capacity that allows for storage of energy sufficient for one or more use experiences. For example, the power source may have a capacity sufficient to continuously generate aerosol for approximately six minutes, or a multiple of six minutes. In another example, the power source may have a capacity sufficient to provide a predetermined number of puffs or discontinuous activation of the heating element.

[0037] A power source may be electrically connected to the third solder spot. A power source may be electrically connected to one of the first solder spot and the second solder spot.

[0038] As used herein, "aerosol-generating device" refers to a device that interacts with an aerosol-forming substrate to generate an aerosol. The aerosol-forming substrate may be part of an aerosol-generating article, for example part of a smoking article. The aerosol-generating device may be a smoking device that interacts with the aerosol-forming substrate of the aerosol-generating article to generate an aerosol that can be inhaled directly into the user's lungs through the user's mouth. The aerosol-generating device may be a holder. The device may be an electrically heated smoking device. The aerosol-generating device may comprise a housing, an electrical circuit, a power source, a heating chamber, and a heating element.

[0039] The term "aerosol-forming substrate" as used herein relates to a substrate capable of emitting one or more volatile compounds capable of forming an aerosol. Such volatile compounds may be emitted by heating the aerosol-forming substrate. The aerosol-forming substrate may conveniently be part of an aerosol-generating article or a smoking article.

[0040] The aerosol-forming substrate may be provided in liquid form. The liquid aerosol-forming substrate may contain additives and ingredients (such as flavorings). The liquid aerosol-forming substrate may contain water, solvents, ethanol, plant extracts, and natural or artificial flavors. The liquid aerosol-forming substrate may contain nicotine. The liquid aerosol-forming substrate may have a nicotine concentration of about 0.5% to about 10% (e.g., about 2%). The liquid aerosol-forming substrate may be contained within a liquid storage portion of the aerosol-generating article, in which case the aerosol-generating article may be labeled as a cartridge.

[0041] The wicking element may have a fibrous or spongy structure. Preferably, the wicking element comprises a bundle of capillaries. For example, the wicking element may comprise a plurality of fibers or threads or other fine tubes. The fibers or threads may be generally aligned to transport the liquid to the heater. Alternatively, the wicking element may comprise a spongy or foam-like material. The structure of the wicking element forms a plurality of small holes or tubes through which the liquid can be transported by capillary action. The wicking element may comprise any suitable material or combination of materials. Examples of suitable materials are sponge or foam materials, ceramic or graphite-based materials in the form of fibers or sintered powders, foamed metal or plastic materials, and fibrous materials, such as fibrous materials made of spun or extruded fibers (such as cellulose acetate, polyester, or bonded polyolefin, polyethylene, ethylene, or polypropylene fibers, nylon fibers, or ceramics). Ceramics are particularly preferred materials for the wicking element. Preferably, the wicking element is a porous wicking element. The wicking element may have any suitable capillary action and porosity for use with different liquid physical properties. The liquid has physical properties, including but not limited to viscosity, surface tension, density, thermal conductivity, boiling point, and vapor pressure, that allow the liquid to be moved through the wicking element by capillary action. The wicking element may be configured to transport the aerosol-forming substrate to the heating element. The wicking element may extend into the gap of the heating element.

[0042] The liquid reservoir may be of any suitable shape and size. For example, the liquid reservoir may be substantially cylindrical. The cross section of the liquid reservoir may be, for example, substantially circular, oval, square, or rectangular.

[0043] The liquid storage portion may comprise a housing. The housing may comprise a base and one or more sidewalls extending from the base. The base and the one or more sidewalls may be integrally formed. The base and the one or more sidewalls may be separate elements attached or fixed to each other. The housing may be a rigid housing. As used herein, the term "rigid housing" is used to mean a freestanding housing. The rigid housing of the liquid storage portion may provide mechanical support for the aerosol-generating means. The liquid storage portion may comprise one or more flexible walls. The flexible walls may be configured to fit the volume of the liquid aerosol-forming substrate stored in the liquid storage portion. The housing of the liquid storage portion may comprise any suitable material. The liquid storage portion may comprise a substantially fluid-impermeable material. The housing of the liquid storage portion may comprise a transparent or translucent portion so that the liquid aerosol-forming substrate stored in the liquid storage portion can be seen by a user through the housing. The liquid storage portion may be configured so that the aerosol-forming substrate stored in the liquid storage portion is protected from ambient air. The liquid reservoir may be configured such that the aerosol-forming substrate stored therein is protected from light, thereby reducing the risk of substrate deterioration and maintaining a high level of hygiene.

[0044] The liquid reservoir may be substantially sealed. The liquid reservoir may include one or more outlets for allowing the liquid aerosol-forming substrate stored in the liquid reservoir to flow from the liquid reservoir to the aerosol generating device. The liquid reservoir may include one or more semi-open inlets, which may allow ambient air to enter the liquid reservoir. The one or more semi-open inlets may be semi-permeable membranes or one-way valves that are permeable to allow ambient air to enter the liquid reservoir and impermeable to substantially prevent air and liquid inside the liquid reservoir from exiting the liquid reservoir. The one or more semi-open inlets may allow air to pass through and enter the liquid reservoir under certain conditions. The liquid reservoir may be permanently disposed in the main body of the aerosol generating device. The liquid reservoir may be refillable. Alternatively, the liquid reservoir may be configured as a replaceable liquid reservoir. The liquid reservoir may be part of or configured as a replaceable cartridge. The aerosol generating device may be configured to receive the cartridge. When the initial cartridge is consumed, a new cartridge may be attached to the aerosol generating device.

[0045] The wicking element is preferably in fluid communication with the liquid reservoir to wick the liquid aerosol-forming substrate from the liquid reservoir and is preferably configured to wick the liquid aerosol-forming substrate from the liquid reservoir to the heating element.

[0046] At least one air inlet may be provided in the wall of the housing of the aerosol generating device. The air inlet may be a semi-open inlet. A semi-open inlet may be an inlet that allows air or fluid flow in one direction, such as into the device, but at least restricts, preferably prohibits, air or fluid flow in the opposite direction. A semi-open inlet preferably allows ambient air to enter the aerosol generating device. Air or liquid may be prevented from exiting the aerosol generating device through the semi-open inlet. A semi-open inlet may be, for example, a semi-permeable membrane that is permeable to air in only one direction but is airtight and liquid-tight in the opposite direction. A semi-open inlet may also be, for example, a one-way valve. A semi-open inlet preferably allows air to pass through the inlet only when certain conditions are met, such as a minimum pressure on the aerosol generating device or the amount of air passing through the valve or membrane.

[0047] In any embodiment of the present disclosure, the heating element may include an electrically resistive material. Suitable electrically resistive materials include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilicide), carbon, graphite, metals, alloys, and composites made of ceramic and metallic materials. Such composites may include doped or undoped ceramics. An example of a suitable doped ceramic is doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum platinum, gold, and silver. Examples of suitable metal alloys include stainless steel, nickel-containing, cobalt-containing, chromium-containing, aluminum-containing, titanium-containing, zirconium-containing, hafnium-containing, niobium-containing, molybdenum-containing, tantalum-containing, tungsten-containing, tin-containing, gallium-containing, manganese-containing, gold-containing, and iron-containing alloys, as well as nickel-, iron-, cobalt-, and stainless steel-based superalloys, Timetal®, and iron-manganese-aluminum-based alloys. In the composite material, the electrically resistive material may optionally be embedded in, encapsulated in, or coated with the insulating material, or vice versa, depending on the required energy transfer kinetics and external physicochemical properties.

[0048] The heating element is preferably configured as a resistance heater disposed between the third solder spot and one of the first and second solder spots. The resistance heater is disposed adjacent to the wicking element, and preferably parallel to the wicking element. Alternatively, the heating element may illustratively be a capillary heater, a mesh heater, or a metal plate heater. The heating element may include, for example, a flat heater having a solid or mesh surface. The heating element may include an array of filaments. The heating element may be disposed in direct contact with the proximal surface of the wicking element.

[0049] The following provides a non-exhaustive list of non-limiting examples, any one or more of the features of which may be combined with any one or more features of any other example, embodiment, or aspect described herein. [Example]

[0050] Example A: 1. A heating assembly for an aerosol generating device, comprising: a first solder spot; a second solder spot; a connecting strip electrically connecting the first solder spot to the second solder spot; A heating assembly, wherein one of the first solder spot and the second solder spot is configured as a soft solder spot having a melting temperature of 200°C to 300°C, and the connecting strip is configured as a bimetal strip. Example B: The heating assembly according to embodiment A, wherein the melting temperature of the soft solder spot is between 225°C and 275°C, preferably about 250°C. Example C: A heating assembly according to either embodiment A or B, wherein the connecting strip is arranged to span freely between the first solder spot and the second solder spot. Example D: A heating assembly according to any of Examples A-C, wherein the connecting strip is configured to be severed from the soft solder spot by bending away from the soft solder spot when the temperature of the connecting strip exceeds 300°C, preferably when the temperature of the connecting strip exceeds 275°C, and most preferably when the temperature of the connecting strip exceeds 250°C. Example E: The heated assembly according to any one of Examples A to D, wherein the melting temperature of the other solder spot that is not the soft solder spot is 600°C to 900°C, preferably 650°C to 850°C, and most preferably 700°C to 800°C. Example F: The heating assembly according to any of embodiments A-E, wherein the bimetallic strip comprises an active layer and a passive layer. Example G: A heating assembly according to any of Examples A-F, wherein the bimetallic strip includes a layer of an alloy of Fe—Ni and a layer of one of Cu, Ni, Fe—Ni—Cr, Fe—Ni—Mn, and Mn—Ni—Cu. Example H: A heating assembly according to any of embodiments A-G, wherein the bimetallic strip is configured so that its shape does not change during normal operating temperatures of the heating assembly. Example I: A heating assembly according to any of embodiments A-H, wherein the normal operating temperature of the heating assembly is between 90°C and 250°C, preferably between 150°C and 245°C, and most preferably between 200°C and 240°C. Example J: A heating assembly according to any of Examples A-I, wherein the soft solder spot comprises one of Sn95Pb5, Pb, Pb75In25, and Pb68Sn32. Example K: A heating assembly according to any of Examples AJ, wherein the soft solder spot comprises one of Sn95Pb5, Pb, Pb75In25, and Pb68Sn32. The heating assembly according to any of Examples AJ, wherein the other solder spot that is not the soft solder spot comprises silver, preferably consists of silver. Example L: A heating assembly according to any of embodiments A-K, wherein the soft solder spot is configured to melt and release the connection strip when the temperature of the soft solder spot exceeds 300°C, preferably when the temperature of the soft solder spot exceeds 275°C, and most preferably when the temperature of the soft solder spot exceeds 250°C. Example M: A heating assembly according to any of Examples A-L, further comprising a third solder spot and a heating filament disposed in electrical connection between the third solder spot and one of the first solder spots of the second solder spot. Example N: An aerosol generating device comprising a heating assembly according to any of embodiments A-M. Example O: The aerosol generating device according to example N, further comprising: a liquid reservoir containing a liquid aerosol-forming substrate; and a wicking element configured to wick the liquid aerosol-forming substrate from the liquid reservoir to the heating assembly. Example P: An aerosol generating device according to embodiment O, wherein one or more first solder spots are soldered onto the wicking element, preferably by a first electrical contact pad, a second solder spot is soldered onto the wicking element, preferably by a second electrical contact pad, and a third solder spot is soldered onto the wicking element, preferably by a third electrical contact pad. Example Q: An aerosol generating device according to one of embodiments N-P, further comprising: a power supply for supplying power to the heater assembly; and a controller for controlling the supply of electrical energy from the power supply to the heater assembly. Example R: The aerosol generating device according to embodiment Q, wherein a power source is electrically connected to the third solder spot and a power source is electrically connected to one of the first solder spot and the second solder spot.

[0051] Features described with respect to one embodiment may equally apply to other embodiments of the invention.

[0052] The invention will now be further described, by way of example only, with reference to the accompanying drawings in which: [Brief explanation of the drawings]

[0053] [Figure 1] FIG. 1 shows an aerosol generating device that utilizes a heating assembly. [Figure 2] FIG. 2 shows the heating assembly. [Figure 3] FIG. 3 shows a cross-sectional view of the heating assembly. [Figure 4]FIG. 4 shows a cross-sectional view of the heating assembly in an overheating scenario. DETAILED DESCRIPTION OF THE INVENTION

[0054] 1 shows an aerosol generating device 10. The aerosol generating device 10 comprises a body 12. A power source in the form of a battery (not shown) is disposed within the body 12. Additionally, an electrical circuit (not shown) is disposed within the body 12. The electrical circuit is configured to control the supply of electrical energy from the power source to the heating assembly 14.

[0055] FIG. 1 further illustrates the cartridge 16. The cartridge 16 includes a liquid reservoir 18 for holding a liquid aerosol-forming substrate. The liquid aerosol-forming substrate is drawn toward the heating assembly 14. The drawing of the liquid aerosol-forming substrate is preferably facilitated by a wicking element 24, as shown in more detail in FIGS. 2-4, discussed below. The heating assembly 14 is sandwiched between the body 12 and the cartridge 16. When the cartridge 16 is attached to the body 12, the heating assembly 14 is securely held between the cartridge 16 and the body 12. Alternatively, the heating assembly 14 may be fixed to the cartridge 16 or the body 12. The cartridge 16 may be replaceable or refillable. The cartridge 16 further includes a mouthpiece 20, through which the aerosol generated by the aerosol generating device 10 exits the device and can be inhaled by a user.

[0056] Fluidly connecting the heating assembly 14 with the mouthpiece 20 provides an airflow channel 44. An aerosol-forming substrate vaporized by the heating assembly 14 can travel through the airflow channel 44 toward the mouthpiece 20. The aerosol may be formed at the heating assembly 14 or downstream of the heating assembly 14 within the airflow channel 44.

[0057] Ambient air may be drawn into the aerosol generating device 10 through an air inlet (not shown) toward the heating assembly 14. The air inlet may be disposed within the body 12 or within the cartridge 16. The air inlet is fluidly connected to the heating assembly 14.

[0058] 2 shows the heating assembly 14 in more detail. The heating assembly 14 includes a heating element 22. The heating element 22 is configured as an electrically resistive filament. The electrically resistive filament is printed on or embedded within a wicking element 24. The heating element 22 is configured to be resistively heated to vaporize a liquid aerosol-forming substrate. The liquid aerosol-forming substrate to be vaporized is provided within the wicking element 24.

[0059] The wicking element 24 has a rectangular shape. The wicking element 24 is disposed parallel to the heating element 22. The liquid aerosol-forming substrate is drawn from the liquid storage portion 18 of the aerosol-generating device 10 toward the wicking element 24. The wicking element 24 is fluidly connected to the liquid aerosol-forming substrate in the liquid storage portion 18.

[0060] The liquid aerosol-forming substrate vaporized by the heating element 22 is entrained in the ambient air that is drawn through the airflow channel towards the mouthpiece 20 .

[0061] Disposed in series with the heating element 22 is a connecting strip 26. The connecting strip 26 is a bimetallic strip. The connecting strip 26 is configured to prevent overheating of the heating assembly 14 by automatically disconnecting the heating assembly 14 electrically in the event of an overheating scenario.

[0062] The connecting strip 26 has an active layer and a passive layer. The active layer is disposed facing the wicking element 24. The passive layer is disposed facing away from the wicking element 24. The connecting strip 26 is disposed so as to freely span between a first solder spot 28 and a second solder spot 30.

[0063] The first solder spot 28 has a melting point of 700° C. to 800° C. Therefore, the first solder spot 28 will not melt even in an overheating scenario.

[0064] The second solder spot 30 has a melting point of approximately 250° C. The second solder spot 30 melts in an overheating scenario.

[0065] An overheating scenario occurs, inter alia, when the liquid aerosol-forming substrate in the liquid storage portion 18 is depleted. Liquid aerosol-forming substrate is then no longer delivered to the wicking element 24. Thus, the wicking element 24 dries out. A dry wicking element 24 can heat up to normal operating temperatures of 200°C to 240°C if the wicking element 26 is dry but the heating element 22 is operational. Overheating prevention measures are facilitated to prevent unwanted vapor from being released from the wicking element 24.

[0066] Overheat protection is facilitated by the melting of the second solder spot 30, which is configured as a soft solder spot. Furthermore, overheat protection is facilitated by the bending action of the connecting strip 26. When the temperature exceeds approximately 250°C, the second solder spot 30 melts. Therefore, the connecting strip 26 is no longer mechanically or electrically attached to the second solder spot 30. The connecting strip 26 bends away from the second solder spot 30 and away from the wicking element 24. The release of the connecting strip 26 due to the melting of the second solder spot 30, along with the bending of the connecting strip 26, results in the electrical disconnection of the connecting strip 26. Because the heating element 22 is connected in series with the connecting strip 26, electrical energy is no longer supplied to the heating element 22. Heating stops. Overheat protection is achieved.

[0067] The heating element 22 is electrically connected to the second solder spot 30 by the second electrical contact pad 32. The second electrical contact pad 32 is disposed directly on the wicking element 24. The second solder spot 30 is in direct contact with the second electrical contact pad 32. The connecting strip 26 is not in contact with the second electrical contact pad 32, but only with the second solder spot 30. Thus, in an overheating scenario, the connecting strip 26 is released while the heating element 22 remains unchanged.

[0068] The first solder spot 28 is disposed on the first electrical contact pad 34. The first electrical contact pad 34 is in direct contact with the wicking element 24. The first solder spot 28 is in direct contact with the first electrical contact pad 34. The first solder spot 28 is in electrical contact with the power source of the body 12 having an electrical connection 40. The heating element 22 is disposed between the second electrical contact pad 32 and the third electrical contact pad 36. The third solder spot 38 is in direct contact with the third electrical contact pad 36. The third electrical contact pad 36 is in direct contact with the wicking element 24. The third solder spot 38 is in electrical contact with the power source of the body 12 having an electrical connection 42.

[0069] Figure 3 shows a cross-sectional view of heating assembly 14 taken along line AA shown in Figure 2. Figure 3 illustrates the arrangement of connecting strip 26 during normal operation of heating assembly 14. Connecting strip 26 is electrically connected to first solder spot 28 and second solder spot 30. Connecting strip 26 is arranged to freely span between first solder spot 28 and second solder spot 30.

[0070] FIG. 4 shows a cross-sectional view of the heating assembly 14 along line AA, similar to FIG. 3. In contrast to FIG. 3, an overheating scenario is shown in FIG. 4. Due to a temperature greater than approximately 250° C., the second solder spot 30 melts. In addition to the melting of the second solder spot 30, the connecting strip 26 bends away from the second solder spot 30 and away from the wicking element 24. Due to these two occurrences, the connecting strip 26 is no longer connected to the second solder spot 30, and the electrical connection of the heating element 22 is interrupted. Therefore, heating stops. Overheating is prevented.

Claims

1. 1. A heating assembly for an aerosol generating device, comprising: a first solder spot; a second solder spot; a connecting strip electrically connecting the first solder spot to the second solder spot; A heating assembly, wherein one of the first solder spot and the second solder spot is configured as a soft solder spot having a melting temperature of 225°C to 275°C, and the connecting strip is configured as a bimetallic strip.

2. The heating assembly of claim 1 , wherein the melting temperature of the soft solder spots is about 250° C.

3. 2. The heating assembly of claim 1, wherein the connecting strip is disposed so as to freely span between the first solder spot and the second solder spot.

4. 2. The heating assembly of claim 1, wherein the connecting strip is configured to be severed from the soft solder spot by bending away from the soft solder spot when the temperature of the connecting strip exceeds 275°C, most preferably when the temperature of the connecting strip exceeds 250°C.

5. 2. The heating assembly of claim 1, wherein the melting temperature of the other solder spot that is not the soft solder spot is between 600°C and 900°C, preferably between 650°C and 850°C, and most preferably between 700°C and 800°C.

6. The heating assembly of claim 1 , wherein the bimetallic strip includes an active layer and a passive layer.

7. 2. The heating assembly of claim 1, wherein the bimetallic strip includes a layer of an alloy of Fe—Ni and a layer of one of Cu, Ni, Fe—Ni—Cr, Fe—Ni—Mn, and Mn—Ni—Cu.

8. The heating assembly of claim 1 , wherein the bimetallic strip is configured so that its shape does not change during normal operating temperatures of the heating assembly.

9. 10. The heating assembly of claim 1, wherein the typical operating temperature of the heating assembly is between 150°C and 245°C.

10. The soft solder spot is Sn 95 Pb 5 , Pb, Pb 75 In 25 , and Pb 68 Sn 32 10. The heating assembly of claim 1, comprising one of:

11. 2. The heating assembly of claim 1, wherein the other solder spot that is not the soft solder spot comprises, and preferably consists of, silver.

12. 2. The heating assembly of claim 1, wherein the soft solder spot is configured to melt and release the connecting strip when the temperature of the soft solder spot exceeds 275°C, most preferably when the temperature of the soft solder spot exceeds 250°C.

13. An aerosol generating device comprising a heating assembly according to any one of claims 1 to 12.

14. 14. The aerosol generating device of claim 13, further comprising a liquid reservoir containing a liquid aerosol-forming substrate, and a wicking element configured to wick the liquid aerosol-forming substrate from the liquid reservoir to the heating assembly.

15. 15. The aerosol generating device of claim 14, wherein one or more of the first solder spots are soldered onto the wicking element, preferably by a first electrical contact pad, the second solder spot is soldered onto the wicking element, preferably by a second electrical contact pad, and the third solder spot is soldered onto the wicking element, preferably by a third electrical contact pad.

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