Aerosol-generating system with pump

Abstract

An aerosol-generating system (10) includes a heater assembly (24) and a manually operated pump (20). The pump includes a hollow member (30) having an inlet portion (32) and an outlet portion (34), where the inlet portion of the hollow member is configured to connect with a liquid storage portion (18) and the outlet portion of the hollow member is fluidly connected with a dispensing assembly (22). The pump is configured for dispensing a liquid aerosol-forming substrate onto the heater assembly and for pumping a liquid aerosol-forming substrate from the liquid storage portion onto the heater assembly through the dispensing assembly.

Description

[0001] This application is a divisional application of the invention patent application entitled “Aerosol generating system with pump”, with an international application date of February 23, 2017, an international application number of PCT / EP2017 / 054253, and a national application number of 201780018410.0. Technical Field

[0002] The present invention relates to a delivery system for a liquid aerosol-forming substrate for use in an aerosol generating system, such as a hand-held electrically operated aerosol generating system. The invention also relates to an aerosol generating system comprising such a delivery system and a method of generating an aerosol in an aerosol generating system. Background Art

[0003] Hand-held electrically operated aerosol generating systems are known which consist of a device portion comprising a battery and control electronics, a cartridge portion comprising a supply of aerosol-forming substrate contained in a liquid storage portion and an electrically operated vaporizer, and a mouthpiece through which the user inhales the aerosol. The vaporizer typically comprises a coil of heating wire wound around an elongate core which is immersed in a liquid aerosol-forming substrate contained in the liquid storage portion.

[0004] EP 0 957 959 B1 discloses an electrically operated aerosol generator for receiving a liquid material from a source, the aerosol generator comprising an electric pump for pumping a metered amount of liquid material from the source through a tube having an open end. A heating element is provided around the tube. After activating the heater, the liquid material in the tube volatilizes. After volatilization, the liquid material expands and leaves the open end of the tube in gaseous form.

[0005] There is a need to provide an aerosol generating system having a low maintenance liquid delivery system and having a desired aerosolization effect. Summary of the invention

[0006] According to a first aspect of the present invention, an aerosol generating system is provided, comprising a heater assembly and a manually operated pump. The manually operated pump defines a pumping volume having an inlet portion and an outlet portion. The inlet portion of the manually operated pump is configured to be connected to a liquid storage portion. The outlet portion of the manually operated pump is fluidly connected to a dispensing assembly to dispense a liquid aerosol-forming substrate onto the heater assembly. The manually operated pump is used to pump a liquid aerosol-forming substrate from the liquid storage portion to the heater assembly via the dispensing assembly.

[0007] By means of examples of the present invention, the liquid aerosol-forming substrate may be provided to the heater assembly without the need for any electrically driven pumping system. Thus, the number of electrical or electronic components that may be susceptible to electromechanical failure is reduced. Furthermore, the wiring scheme of such a delivery system is less complex, which simplifies both maintenance and assembly of the aerosol generating system.

[0008] The pumping volume of the manually operated pump may be defined by a hollow member having at least one wall, and wherein at least a portion of this wall is flexible. Alternatively, the pumping volume of the manually operated pump may be defined by a hollow member having at least one wall and a plunger movable within the hollow member. The term "pumping volume" as used herein is defined as the internal volume of the hollow member extending between the inlet and outlet of the hollow member. In some embodiments, the hollow member defining the pumping volume may be a hollow flexible member, such as a hollow flexible tube. Using a hollow flexible tube with two ends forming the inlet and outlet portions creates a particularly simple and reliable design that can be produced in a cost-effective manner.

[0009] The manually activated pump may include a volume regulator configured to change the pumping volume of the manually operated pump. The volume regulator may be configured to be manually operated by a user. The volume regulator may include a movable element engaged with at least one flexible portion or plunger of the wall of the pumping volume. When the user operates the volume regulator, the movable element may be pressed against at least one flexible portion or plunger of the hollow member so that the internal volume of the hollow member changes. When the movable element is pressed against at least one flexible portion or plunger of the hollow member, the internal volume of the hollow member is reduced, thereby forming an overpressure in the pumping volume. Due to this overpressure excess, the liquid aerosol-forming substrate contained in the pumping volume is discharged through the outlet portion of the pumping volume. When the movable element is released from at least one flexible portion or plunger of the hollow member, the internal volume of the hollow member expands to its initial size, thereby forming a negative pressure in the pumping volume. Due to this negative pressure, the liquid aerosol-forming substrate is pumped from the liquid storage portion to the pumping volume of the hollow member.

[0010] The inlet and outlet portions of the hollow member of the manually operated pump may each include a one-way valve. The one-way valve at the inlet portion of the hollow member may only allow liquid to flow from the connected liquid storage portion into the pumping volume. The one-way valve at the outlet portion of the hollow member may only allow liquid to flow from the pumping volume to the dispensing assembly.

[0011] Any commercially available one-way valve of sufficient size and liquid flow may be used, including mini and micro wing valves, duckbill valves or check valves. The valve may be made, for example, of a material resistant to aggressive chemicals or of a material that can be used in the food industry and medical applications.

[0012] In one embodiment of the invention, the pumping volume is defined by a hollow flexible tube having an outlet portion and an inlet portion, each of which is provided with a non-return valve. The volume regulator comprises a movable element and a fixed element. The flexible tube is positioned between the fixed element and the movable element of the volume regulator so that by moving the movable element towards the fixed element, the internal volume of the tube is reduced.

[0013] The movable member of the volume adjuster may be connected to a button provided in the housing of the aerosol generating system, such that a user can easily operate the volume adjuster.

[0014] A resilient member may be provided which ensures that the movable member returns to its original position after the user releases the volume adjuster.

[0015] During operation of the pumping unit, the size of the hollow element and its foldable proportions are directly related to the volume of liquid dispensed onto the heater assembly to form an aerosol, and may be limited to specify a maximum liquid volume per pumping pulse. In embodiments using a flexible hollow tube, the outer diameter of the tube may be in the range of 2 to 8 mm, and may preferably be in the range of 3 to 5 mm.

[0016] The maximum amount of liquid that should be pumped as one puff dose may be a small volume of 0.010 to 0.060 μl, preferably about 0.0125 μl.

[0017] The force and displacement required to squeeze the hollow member of the manually operated pump are extremely small. Therefore, an elastic member can also be used in order to define the minimum force required to operate the volume regulator. This force can be selected substantially freely and can be adapted to the user's habits or expectations. The force can be adjusted to be in the range of 0.1 to 1.0 Newton, and preferably in the range of 0.5 to 0.8 Newton.

[0018] The displacement of the movable member is also freely selectable and can be adapted to the design of the specific embodiment. The displacement can be adjusted to vary within the range of 0.4 to 5.0 mm, and can preferably vary within the range of 0.7 to 3.0 mm.

[0019] The inlet portion of the manually operated pump is configured for connection to the liquid storage portion. The connection between the manually operated pump and the liquid storage portion may be a permanent connection or a releasable connection. In some embodiments, the liquid storage portion may be refillable. In some embodiments, the liquid storage portion may be replaceable and may be replaced when it is empty or when a user would like to use a different type of liquid for aerosol generation. The releasable connection between the manually operated pump and the liquid storage portion may be established by any suitable connection means, including a Luer taper (locking or assembly type).

[0020] The pump may be configured to pump a liquid aerosol-forming substrate characterized by a relatively high viscosity compared to water.The viscosity of the liquid aerosol-forming substrate may be in the range of about 10 to 500 mPas, preferably in the range of about 17 to 86 mPas.

[0021] A nozzle may be provided at the outlet end of the dispensing assembly, through which a liquid aerosol-forming substrate may be sprayed onto the heater assembly for volatilization and aerosol formation. The nozzle converts the liquid aerosol-forming substrate stream into a plurality of small droplets. The spray pattern of the droplets may be adapted to the shape of the heater assembly.

[0022] The delivery device may comprise a conventional type of atomizer spray nozzle, in which case the airflow is supplied via the nozzle by the user's puffing action, thereby forming a pressurized airflow that will mix and act with the liquid forming an atomized spray in the outlet of the nozzle. Several systems are available on the market that include nozzles that act on smaller amounts of liquid and are sized to meet the requirements of being assembled in a small portable device. Another category of nozzles that can be used is an airless spray nozzle, which is sometimes referred to as a micro-spray nozzle. Such nozzles produce a very small micro-spray cone. With this category of nozzles, the airflow management inside the device, i.e. the airflow management inside the mouthpiece, surrounds the nozzle and the heating element, thereby flushing the heater assembly towards the mouthpiece outlet, preferably including a turbulent flow pattern of the aerosol leaving the mouthpiece.

[0023] For either class of nozzles, the distance of the air gap between the transfer device and the sheet heater assembly facing the nozzle is preferably in the range of 2 to 10 mm, more preferably in the range of 3 to 7 mm. Any type of available spray nozzle may be used. The airless nozzle 062 Minstac from the manufacturer "The Lee Company" is an example of a suitable spray nozzle.

[0024] The heater assembly may include any type of heating element suitable for vaporizing a liquid aerosol-forming substrate. The heater assembly may be substantially flat in some instances and may have any desired shape. The heater assembly may, for example, have a rectangular, polygonal, circular or oval shape and may have a width and length dimension between 3 and 10 millimeters.

[0025] The heating element may comprise a thin, preferably substantially flat, electrically conductive material suitable for receiving and heating an aerosol-forming substrate for use in an aerosol generating system, such as a fibrous web, an electrically conductive film, or an array of heating strips.

[0026] The heating element may include a plurality of openings. For example, the heating element may include a web of fibers with gaps therebetween. The heating element may include a film or plate optionally perforated with small holes. The heating element may include an array of narrow heating strips connected in series.

[0027] The heater assembly may include a heat-resistant substrate and a heating element disposed in the heat-resistant substrate or on the surface of the heat-resistant substrate. The heat-resistant substrate of the heater assembly may be made of glass, heat-resistant glass, ceramic, silicon, semiconductor, metal or metal alloy.

[0028] The heat-resistant substrate may be substantially flat and may have any desired shape. The heat-resistant substrate may have, for example, a rectangular, polygonal, circular, or oval shape with width and length dimensions between 3 and 10 millimeters. The thickness of the heat-resistant substrate may range between 0.2 and 2.5 millimeters. In some embodiments, the heat-resistant substrate may have a rectangular shape with a size of about 7×6 millimeters or 5×5 millimeters (L×W).

[0029] The heating element can be provided as a thin film coating provided to the surface of the heat-resistant substrate. The heating element can be impregnated, deposited or printed on the surface of the heat-resistant substrate. The material of the thin film heating element can be any suitable material with suitable electrical properties and sufficiently high adhesion to the heat-resistant substrate.

[0030] The heating element may be disposed within the volume of the heat resistant substrate, may be sandwiched between two elements of the heat resistant substrate, or may be covered by a protective layer of heat resistant material.

[0031] In some embodiments, the liquid aerosol-forming substrate may be delivered to the front side of the heat resistant substrate and the heating element may be provided on the back side of the heat resistant substrate.

[0032] The heater assembly can be spaced apart from the dispensing assembly. By providing a heater assembly spaced apart from the transfer assembly, the amount of the liquid aerosol formed by the heater assembly can be better controlled than the vaporizer with a pipeline section for the liquid aerosol to form the substrate flow from the transfer assembly to the heater assembly. The undesirable capillary action caused by this pipeline section can be avoided. When passing through the air gap, the liquid aerosol of the amount transferred forms the jet of the substrate before the surface of the impact heater assembly will be transformed into a droplet. Therefore, in some instances, the liquid aerosol of the amount transferred can be enhanced to form the uniform distribution of the substrate on the heater assembly, thereby better controlling and repeating the generation of the vaporized aerosol with a predetermined amount of substrate per inhalation cycle.

[0033] The operating temperature of the heater assembly may be between 120 and 210 degrees C, preferably between 150 and 180 degrees C. In some examples, the operating temperature may vary.

[0034] The aerosol generating system may be configured such that upon activation of the pumping unit by the user, an electrical signal is generated and transmitted to the control unit. For this purpose, the movable member of the volume regulator may be connected to an electromechanical switch in electrical communication with the control unit. Thus, activation of the pumping unit may also simultaneously trigger the control unit to activate the heater assembly.

[0035] The electrical communication with the control unit can be established by corresponding wiring between the switch and the control unit. The electrical communication with the control unit can also be established by a wireless interface, for example a switch that sends a signal remotely to the control unit, which can be placed at the other end of the device relative to the position of the switch.

[0036] The switch can be designed as a kinetic self-powered electronic component. Such kinetic electronic switches do not require wiring connections to a control unit and power supply, because the electrical energy required to generate and send the signal is generated by the action of pressing the switch button. Single-button-activated kinetic electronic switches for remote signaling are commercially available. Applicable solutions available in the market include highly compressed, small and thin electronic parts, including thin-film flexible electronic parts. Eliminating or reducing wires and electrical contacts simplifies the design and assembly of the aerosol generating system and improves the overall reliability.

[0037] The kinetic electronics may also communicate with further surrounding devices, and in particular also with further electronics used in the aerosol generating system, such as sensors.

[0038] The aerosol generating system may be an electrically operated aerosol generating system. Preferably, the aerosol generating system is portable. The aerosol generating system may have a size comparable to a conventional cigar or cigarette. The aerosol generating system may have an overall length of between approximately 30 mm and approximately 150 mm. The aerosol generating system may have an outer diameter of between approximately 5 mm and approximately 30 mm.

[0039] According to a second aspect of the present invention, a method for generating an aerosol is provided, comprising the following steps: providing a heater assembly; and providing a manually operated pump, the manually operated pump comprising a hollow member having an inlet portion and an outlet portion. The inlet portion of the hollow member is configured to be connected to a liquid storage portion, and the outlet portion of the hollow member is fluidly connected to a dispensing assembly. The method further comprises operating the manually operated pump to pump a liquid aerosol-forming substrate from the liquid storage portion to the heater assembly through the dispensing assembly.

[0040] Features described in relation to one aspect may be equally applicable to other aspects of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0042] Figure 1 is a side view of an exemplary embodiment of an aerosol generating system in a standby mode;

[0043] Figure 2Demonstrates the volume regulator during manual operation Figure 2 delivery system;

[0044] Figure 3 Shows the volume regulator after manual activation Figure 2 delivery system; and

[0045] Figure 4 is a schematic illustration of an alternative mechanism for adjusting the interior volume of a hollow member. DETAILED DESCRIPTION

[0046] Figure 1 Components of an aerosol generating system of the present invention are shown in an initial or standby mode. The aerosol generating system 10 comprises a housing 12, a power source 14, a control unit 16, a liquid storage portion 18, a manually operated pump 20, a dispensing assembly 22 and a heater assembly 24. The housing comprises an air inlet 26 and a mouthpiece 28 at its proximal end. In use, a user sucks or puffs at the mouthpiece, thereby forming an air flow from the air inlet 26 towards the mouthpiece 28 through the heater assembly 24.

[0047] The manually operated pump 20 is configured to collect liquid from the liquid storage portion 18 and pump it in a controllable manner onto the heater assembly 24. The pump 20 comprises a flexible hollow tube 30 having an inlet portion 32 and an outlet portion 34 and defining a pumping volume 36 therebetween. One-way valves 38, 40 are provided at both ends of the tube 30, wherein the one-way valve 38 at the inlet portion 32 allows the liquid aerosol-forming substrate to enter the pumping volume 36, and wherein the one-way valve 40 at the outlet portion 34 allows the liquid aerosol-forming substrate to leave the pumping volume 36. A volume regulator comprising a fixed element 44 and a movable element 46 is provided at opposite sides of the flexible hollow tube 30. The movable element 46 is connected to a button 48 provided in the housing 12 of the aerosol generating system 10.

[0048] exist Figure 1 In FIG. 1 , the manually operated pump is depicted in an initial position in which the pumping volume is completely filled with the liquid aerosol-forming substrate.

[0049] When the user presses button 48, Figure 2 As depicted in FIG. 4 , the hollow tube 30 is squeezed between the movable element 46 and the fixed element 44. As a result, the pumping volume 36 is reduced and an overpressure is formed in the pumping volume 36. In order to compensate for the overpressure, part of the liquid aerosol-forming substrate is discharged through the outlet portion 34 of the hollow tube 30. This is caused by Figure 250 in the figure. The outlet portion 34 is fluidly connected to the dispensing assembly 22. The dispensing assembly 22 includes a conduit 52 and a spray nozzle 54. The spray nozzle 54 is an airless spray nozzle that forms a spray cone 56 of small droplets of a liquid aerosol-forming substrate, which is uniformly delivered to the heater assembly 24.

[0050] The heater assembly 24 is electrically connected to the power source 14 via wiring 58 and is controlled by the control unit 16. The control unit 16 communicates with an electrical switch 62 connected to the button 48 via wiring 60. Thus, upon activation of the manually operated pump via the button 48, the user generates an electrical signal via the electrical switch 62, and the control unit 16 then activates the heater assembly 24 to volatilize the delivered liquid aerosol-forming substrate.

[0051] When pressing the button 48, the user may draw one puff at the mouthpiece 28, thereby forming an air flow between the air inlet 26 and the mouthpiece 28. The volatilized liquid aerosol-forming substrate mixes with the air flow, thereby forming an aerosol to be inhaled by the user.

[0052] When the button 48 is released, Figure 3 As depicted in FIG. 4 , the movable element 46 is returned to its original position by the resilient spring member 64. The hollow tube 30 regains its original size, thereby forming a negative pressure in the pumping volume 36. To compensate for the negative pressure, fresh liquid aerosol-forming substrate is pumped from the liquid storage portion 18 into the pumping volume 36 through the inlet valve 38. This is accomplished by Figure 3 Indicated by arrow 66 in FIG. 1 . In this embodiment, the liquid storage portion 18 comprises a folded bag. When the liquid aerosol-forming substrate is pumped from the liquid storage portion 18, the volume of the folded bag decreases.

[0053] The embodiments described above rely on flexible walls to adjust the internal volume of the hollow member. However, other ways of adjusting the volume of the hollow member are possible.

[0054] Figure 4 1 is a schematic illustration of an alternative mechanism for adjusting the internal volume of a hollow member in a manually operated pump. The hollow member 100 includes a rigid wall 105 that contains a volume of liquid. The hollow member 100 is shown with reference to Figures 1 to 3The described manner is connected to the liquid storage portion through the inlet valve 110 and to the heater assembly through the outlet valve 115. The plunger 120 can move in the hollow member 100 and maintain a liquid-tight seal with the rigid wall 105 when moving. The internal volume 108 of the hollow member is defined between the rigid wall 105, the inlet valve 110, the outlet valve 115 and the plunger 120. The movement of the plunger in the hollow member changes the internal volume. The plunger is fixed to a button 125, which can be pressed by a user to move the plunger, thereby reducing the internal volume of the hollow member. A return spring 130 is provided between the button and the rigid wall 105 to return the plunger to an initial position when the button is released. When the button is pressed by the user, the liquid in the hollow member is forced to leave through the outlet valve 115, and when the button is released, the plunger returns to its initial position and the liquid is sucked into the hollow member through the inlet valve 110.

[0055] The exemplary embodiments described above are illustrative and not limiting.In view of the exemplary embodiments discussed above, other embodiments consistent with the above exemplary embodiments will now be apparent to those of ordinary skill in the art.

Claims

1. An aerosol generating system, comprising: heater assembly, and A manually operated pump comprising a hollow member having an inlet portion and an outlet portion and a volume regulator having a movable element, the volume regulator being configured to vary the internal volume of the hollow member, wherein The inlet portion of the hollow member is configured to be connected to a liquid storage portion, The outlet portion of the hollow member is fluidly connected to a dispensing assembly to dispense a liquid aerosol-forming substrate onto a heater assembly, the inlet portion and the outlet portion each comprising a one-way valve, wherein the one-way valve at the inlet portion only allows liquid to flow from the liquid storage portion into the hollow member, and wherein the one-way valve at the outlet portion only allows liquid to flow from the hollow member to the dispensing assembly; and wherein the manually operable pump is used to pump liquid aerosol-forming substrate from the liquid storage portion through the dispensing assembly to the heater assembly.

2. An aerosol generating system according to claim 1, wherein the hollow member comprises at least one wall, and wherein at least a portion of the wall is flexible.

3. An aerosol generating system according to claim 2, wherein the volume regulator is configured to press against a flexible portion of the at least one wall of the hollow member of the manually-operated pump, and wherein upon compression of the hollow member, the internal volume of the hollow member is reduced and the liquid aerosol-forming substrate comprised in the hollow member is discharged through the outlet portion of the hollow member, and Wherein, upon expanding the hollow member, liquid aerosol-forming substrate is pumped from the liquid storage portion into the interior volume of the hollow member through the inlet portion.

4. An aerosol generating system according to any one of the preceding claims, wherein the volume regulator comprises a movable element and a fixed element, wherein the hollow member of the manually-operated pump is defined by a flexible tube, and Wherein the flexible tube is positioned between the fixed element and the movable element of the volume regulator such that by moving the movable element towards the fixed element the internal volume of the tube is reduced, and vice versa.

5. An aerosol generating system according to claim 4, wherein the volume adjuster comprises a resilient element which helps the movable element to return to its initial position when the volume adjuster is released by a user.

6. An aerosol generating system according to any one of the preceding claims, wherein the dispensing assembly comprises a nozzle for spraying the liquid aerosol-forming substrate onto the heater assembly.

7. An aerosol generating system according to any preceding claim, wherein upon activation of the pump, a predetermined amount of liquid aerosol-forming substrate is transferred to the heater assembly.

8. An aerosol generating system according to any one of the preceding claims, wherein the heater assembly comprises a resistive heating element, a metal mesh or a metal thin film coating on a non-conductive, heat-resistant substrate.

9. An aerosol generating system according to any one of the preceding claims, wherein the movable element is connected to an electronic switch which forms an electrical signal when the volume regulator is operated.

10. An aerosol generating system according to claim 9, wherein the electronic switch is a kinetic electronic switch, and wherein a signal generated by actuation of the switch is transmitted to a control unit via a wireless communication channel.

11. A method of delivering a liquid aerosol-forming substrate, comprising: A heater assembly is provided, and A manually operated pump is provided, the manually operated pump comprising a hollow member having an inlet portion and an outlet portion and a volume adjuster having a movable element, the volume adjuster being configured to change the internal volume of the hollow member, wherein The inlet portion of the hollow member is configured to be connected to a liquid storage portion, and the outlet portion of the hollow member is fluidly connected to a dispensing assembly, the inlet portion and the outlet portion each comprising a one-way valve, wherein the one-way valve at the inlet portion only allows liquid to flow from the liquid storage portion into the hollow member, and wherein the one-way valve at the outlet portion only allows liquid to flow from the hollow member to the dispensing assembly; and The manually operable pump is operated to pump liquid aerosol-forming substrate from the liquid storage portion through the dispensing assembly and onto the heater assembly.

12. The method of claim 11, wherein the manually operated pump is operated by actuating a volume regulator comprising a movable element, The movable element is connected to an electronic switch which generates an electronic signal whenever the volume adjuster is activated.

13. A method according to any one of claims 11 or 12, wherein the electronic switch is a kinetic manual electronic switch, and wherein the generated signal is transmitted to a control unit via a wireless communication channel.

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