WO2019175102A1

WO2019175102A1 - Cleaning tool for heating element using suction effect

Info

Publication number: WO2019175102A1
Application number: PCT/EP2019/056018
Authority: WO
Inventors: Tony Reevell
Original assignee: Philip Morris Products S.A.
Priority date: 2018-03-13
Filing date: 2019-03-11
Publication date: 2019-09-19

Abstract

The invention relates to a cleaning tool for cleaning an aerosol-generating device. The aerosol-generating device comprises a heating chamber and a heating element arranged in the heating chamber. The cleaning tool comprises a hollow casing and a plunger. The casing is configured to be inserted into the heating chamber. The plunger is configured to be movably and sealingly inserted into the casing.

Description

CLEANING TOOL FOR HEATING ELEMENT USING SUCTION EFFECT

The present invention relates to a cleaning tool for cleaning an aerosol-generating device.

For generating an inhalable aerosol, aerosol-generating devices are known which heat but not burn an aerosol-generating substrate. The substrate typically comprises an aerosol-former and homogenised tobacco material. The substrate may be wrapped with a wrapping paper and provided in the form of a disposable rod such as a heat stick. The known aerosol-generating device comprises a heating chamber, in which the aerosol-generating substrate can be inserted. A heating element such as a heating blade is also arranged in the heating chamber of the aerosol-generating device. During operation of the aerosol generating device, the aerosol-generating substrate is penetrated by the heating element and subsequently heated to generate an inhalable aerosol. After depletion of the aerosol generating substrate, the substrate is removed from the heating chamber of the aerosol generating device. A fresh aerosol-generating substrate can then be inserted into the heating chamber. However, residues of the aerosol-generating substrate may remain in the heating chamber and on the heating element.

Thus, there is a need for a device for cleaning the heating chamber and the heating element of the aerosol-generating device after operation and removal of the aerosol generating substrate.

According to a first aspect of the invention there is provided a cleaning tool for cleaning an aerosol-generating device. The aerosol-generating device comprises a heating chamber and a heating element arranged in the heating chamber. The cleaning tool comprises a hollow casing and a plunger. The casing is configured to be inserted into the heating chamber. The plunger is configured to be movably and sealingly inserted into the casing.

The casing of the cleaning tool is inserted into the heating chamber of the aerosol generating device and subsequently, the plunger is inserted into the casing. A suction effect is generated by removing the plunger from the casing of the cleaning tool. In this regard, a negative pressure is created inside of the heating chamber during removal of the plunger from the casing of the cleaning tool. The negative pressure may result in residues of aerosol forming substrate being entrained in the airflow and drawn into the casing of the cleaning tool. After removal of the plunger from the casing, the casing may as well be removed from the heating chamber of the aerosol-generating device such that the residues from the heating chamber are removed. The negative pressure is created, since the plunger is sealingly inserted into the casing of the cleaning tool. Sealingly inserting the plunger means that essentially no air can enter into the heating chamber between the casing and the plunger. Preferably, this sealing action is facilitated by corresponding shapes of the hollow casing and the plunger. Air can only be sucked into the heating chamber during removal of the plunger through air inlets of the aerosol-generating device or between the casing of the cleaning tool and in the inner sidewalls of the heating chamber.

The casing of the cleaning tool may be cylindrical. The casing preferably comprises a first open end, into which the plunger is inserted. This end is also referred to as the proximal end of the casing. Opposite to the proximal end, the casing preferably comprises a second open end, which is also referred to as the distal end of the casing. The distal end of the casing is preferably inserted first into the heating chamber of the aerosol-generating device. When the plunger is removed from the casing, air is prevented to enter into the casing from the proximal end, but allowed to enter into the casing from the distal end. Since the distal end is open, residues of aerosol-forming substrate may be sucked into the casing during removal of the plunger from the casing via the proximal end of the casing. The casing may be made from plastic or metal. The casing may be made from any suitable material with a sufficient structural integrity.

The plunger may be cylindrical. The plunger may have a shape which corresponds to the shape of the hollow inner of the casing of the cleaning tool. The plunger may be configured as an elongate cylindrical plunger. The plunger may be made from plastic or metal. The plunger may have a diameter which corresponds to the inner diameter of the casing. The plunger may have the shape of the plunger used in a syringe. Hence, the plunger may comprise a disk or plate-shaped element with a diameter corresponding to the inner diameter of the casing. The rest of the plunger may in this case have an elongate shape with sufficient structural integrity such as a cross-shaped profile.

The cleaning tool may further comprise a handle, which is connected with the plunger. The handle may be provided at a proximal end of the plunger. When the plunger is inserted into the casing of the cleaning tool, the proximal end of the plunger is arranged adjacent to the proximal end of the casing, while a distal end of the plunger is arranged adjacent to the distal end of the casing. The handle may have a diameter which is larger than the inner diameter of the casing so that the handle rests against the proximal end of the casing when the plunger has been inserted into the casing.

The handle preferably comprises a structured surface to facilitate gripping of the handle by a user. The structured surface may have any suitable shape such as grooves, ribs or protrusions. For example, grooves may be arranged axially around the handle so that a gripping action of the handle at the sides of the handle is optimized. The handle may have a hollow or porous structure and may be configured elastically compressible to increase the suction effect during extraction of the plunger. The handle may be made of a spongy or hollow or porous or fibrous elastic material. The outer surface of the handle may be made from a material which does not allow air to flow through the outer surface of the handle. However, the outer surface of the handle preferably is also made from an elastic material. When the plunger is inserted into the casing of the cleaning tool, the handle may preferably be compressed by a user pressing onto the handle. Subsequently, the user preferably removes the handle and the plunger from the casing of the cleaning tool. During the removal of the plunger together with the handle, the handle expands to its original shape due to the elastic property of the handle. During the expansion of the handle to its original shape, additional air is sucked into the handle. Since air cannot enter into the handle through the outer surface of the handle, air is drawn into the handle through the plunger. The only way air can enter into the plunger is via the heating chamber of the aerosol-generating device. Hence, the suction effect may be enhanced by an elastically compressible handle. For enabling air to enter the handle via the plunger, the plunger is preferably made from a material which allows air to pass through the plunger. For example, the plunger may also be made from a spongy or hollow or porous or fibrous material. The plunger may be hollow or comprise air channels.

The casing may comprise at least one gap at the distal end of the casing. The gap may be configured to allow air to enter from the side of the casing into the casing, when the casing contacts the base of the heating chamber. The size of the gap may be adjusted to control the strength which is required to remove the plunger from the casing. When no gap is provided or a small gap is chosen, air may only enter into the casing in small amounts, for example between the base of the heating chamber and the casing. Choosing a larger gap or multiple gaps enables more air to enter into the casing over time. Hence, the plunger can more easily removed from the casing, if a larger gap or multiple gaps are provided.

Air may be drawn into the casing between the casing and the inner sidewalls of the heating chamber of the aerosol-generating device. Also, air may be drawn into the casing through air inlets which are already provided in the aerosol-generating device. These air inlets are normally used such that a user can draw air through the aerosol-forming substrate which is arranged within the heating chamber. If the cleaning tool is inserted into the heating chamber instead of the aerosol-forming substrate, the already provided air inlets can then be used such that air can be drawn into the casing during removal of the plunger from the casing of the cleaning tool.

The plunger may comprise a recess. The recess may be configured such that the plunger can be inserted into the heating chamber over the heating element. In the heating chamber of the aerosol-generating device, typically a heating element is provided. The heating element may be a blade-shaped heating element arranged centrally aligned along the longitudinal axis within the heating chamber of the aerosol-generating device. The recess in the plunger may enable the plunger to be inserted into the heating chamber all the way up to the base of the heating chamber.

The plunger may be configured to reach to the base of the heating chamber, when the plunger is inserted into the heating chamber. When the plunger is inserted into the heating chamber, essentially all the air in the heating chamber may be displaced by the plunger. In this way, the suction effect during removal of the plunger can be enhanced.

The plunger may comprise a roughened surface at the end of the plunger which contacts the base of the heating chamber, when the plunger is inserted into the heating chamber. This roughened surface may be used to loosen residues of aerosol forming substrate from the base of the heating chamber. A user may rotate the plunger before removing the plunger from the casing of the cleaning tool. The rotation of the plunger may further aid to loosen or scrap off residues of the aerosol-forming substrate from the base of the heating chamber.

The outside sidewalls of the casing may similarly be provided with a roughened surface such that residues of the aerosol-forming substrate may be scraped off of the inner sidewalls of the heating chamber during insertion of the casing into the heating chamber. All of the loosened and scraped off residues may be pulled into the casing during removal of the plunger by the generated sucking action.

The casing may be configured to have the same outer diameter as the inner diameter of the heating chamber so that essentially no air can flow between the casing and the inner sidewalls of the heating chamber, when the casing has been inserted into the heating chamber. In this case, air can preferably only enter into the casing by air inlets of the aerosol generating device.

The casing or the plunger or the casing and the plunger may comprise a sealing element, wherein the sealing element may be configured to prevent air from flowing between the casing and the plunger. Such a sealing element could for example be provided as an O- ring or any other known sealing element. The sealing element could be arranged around the outer circumference of the plunger. The plunger may comprise a corresponding recess to mount the sealing element. Alternatively or additionally, the inner sidewalls of the casing may be provided with a sealing element. Again, the inner sidewalls of the casing may be provided with a recess to mount the sealing element.

The invention also relates to an aerosol-generating device and a cleaning tool as described above for cleaning the aerosol-generating device. The aerosol-generating device comprises a heating chamber and a heating element arranged in the heating chamber. The casing of the cleaning tool is configured to be inserted into the heating chamber. The plunger of the cleaning tool is configured to be movably and sealingly inserted into the casing.

The aerosol-forming substrate utilized in the aerosol-generating device may be a solid aerosol-forming substrate. Alternatively, the aerosol-forming substrate may comprise both solid and liquid components. The aerosol-forming substrate may comprise a tobacco- containing material containing volatile tobacco flavour compounds which are released from the substrate upon heating. Alternatively, the aerosol-forming substrate may comprise a non tobacco material. The aerosol-forming substrate may further comprise an aerosol former. Examples of suitable aerosol formers are glycerine and propylene glycol.

The heating element may be an electrically resistive heating element. The heating chamber may have a cylindrical shape. The heating element may take the form of a heating blade or an electrically resistive metallic tube. Alternatively, the heating element may be one or more heating needles or rods that run through the center of the aerosol forming substrate. Optionally, the heating element may be deposited in or on a rigid carrier material. The heating element may be formed as a track on a suitable insulating material, such as ceramic material, and then sandwiched in another insulating material, such as a glass. The heating element advantageously heats the aerosol-forming substrate by means of conduction.

During operation of the aerosol-generating device, the aerosol-forming substrate provided in the form of an article such as a heat stick may be partially contained within the aerosol-generating device. In that case, the user may puff directly on the article. The article may be substantially cylindrical in shape. The article may be substantially elongate. The article may have a length and a circumference substantially perpendicular to the length. The aerosol-forming substrate may be substantially cylindrical in shape. The aerosol-forming substrate may be substantially elongate. The aerosol-forming substrate may also have a length and a circumference substantially perpendicular to the length.

The aerosol-generating device may comprise a sensor for activating the heating element. The sensor may preferably be provided as an airflow sensor within the aerosol generating device. The airflow sensor may detect an airflow in an airflow path through the device, when a user draws onto the aerosol-forming substrate. The sensor may also be configured as a negative pressure sensor. The negative pressure sensor may detect that a user draws onto the aerosol-forming substrate, since this may result in a negative pressure in an airflow path through the device. The heating element may also be activated by an on-off button. The aerosol-generating device may further comprise a power supply for supplying power to the heating element. The power supply may be any suitable power supply, for example a DC voltage source. In one embodiment, the power supply is a Lithium-ion battery. Alternatively, the power supply may be a Nickel-metal hydride battery, a Nickel cadmium battery, or a Lithium based battery, for example a Lithium-Cobalt, a Lithium-Iron-Phosphate, Lithium Titanate or a Lithium-Polymer battery.

The aerosol-generating device may further comprise electric circuitry. The electric circuitry may comprise a microprocessor, which may be a programmable microprocessor. The microprocessor may be part of a controller. The electric circuitry may comprise further electronic components. The electric circuitry may be configured to regulate a supply of power from the power supply to the heating element. Sensor data from the sensor may be sent to the electric circuitry, so that the electric circuitry can control the activation of the heating element and the supply of electrical power to the heating element.

The invention also relates to a method for cleaning an aerosol-generating device with a cleaning tool. The aerosol-generating device comprises a heating chamber and a heating element arranged in the heating chamber. The cleaning tool comprises a hollow casing and a plunger. The plunger is configured to be movably and sealingly inserted into the casing. The method comprises the steps of:

inserting the casing into the heating chamber;

inserting the plunger into the casing; and

extracting the plunger out of the casing to generate a suction effect.

Preferably, the method comprises the further step, during the insertion of the plunger into the casing, of compressing the handle to increase the suction effect during extraction of the plunger. To facilitate the compression of the handle, the handle is preferably configured elastic and hollow or porous as described above.

The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

Fig. 1 shows a cross-section through the cleaning tool according to the invention,

Fig. 2 shows an illustration of a plunger of the cleaning tool as well as a casing of the cleaning tool,

Fig. 3 shows a cross-section through the cleaning tool according to the invention inserted into the heating chamber of an aerosol-generating device,

Fig. 4 shows the airflow route in the aerosol-generating device and into the casing of the cleaning tool, Fig. 5 shows an embodiment of the plunger with a recess, and

Fig. 6 shows an illustration of the cleaning tool according to the invention inserted into the heating chamber of the aerosol-generating device.

Fig. 1 shows the cleaning tool according to the present invention. In Fig. 1 , the cleaning tool is depicted comprising a casing 10 and a plunger 12. Also, a handle 14 is depicted which is arranged at a proximal end 16 of the plunger 12. The handle 14 will be described in more detail below with reference to Fig. 2.

The plunger 12 has a cylindrical shape. The casing 10 has a hollow cylindrical shape. The plunger 12 has a shape such that the plunger 12 fits inside of the casing 10. The diameter of the plunger 12 corresponds to the inner diameter of the casing 10. The plunger 12 as well as the casing 10 have an elongate shape.

In the left part of Fig. 1 , the plunger 12 has been fully inserted into the casing 10, until the handle 14 abuts the proximal end 18 of casing 10. In the right part of Fig. 1 , the plunger 12 is removed from the casing 10. Since essentially no air can enter the casing 10 through the handle 14 or between the plunger 12 and casing 10, air can only enter into the casing through the open distal end 20 of the casing 10. Due to the fact that air can only enter into the casing through the open distal end 20 of the casing 10, a suction effect occors, when the plunger 12 is removed from the casing 10. As indicated by the arrows in the right part of Fig. 1 , air enters the casing 10 due to the created suction effect.

Fig. 2 shows an illustration of the plunger 12 being inserted into the casing 10 and removed from the same. Again, in the left part of Fig. 2, the plunger 12 is fully inserted into the casing 10. In the right part of Fig. 2, the plunger 12 is removed from the casing 10, resulting in a suction effect, which draws air into the casing 10 through the open distal end 20.

In Fig. 2, the handle 14 is depicted in more detail. In this regard, the handle 14 comprises a structured surface. By means of the structured surface, the handle 14 can easily be gripped by a user. The structured surface preferably comprises grooves extending around the outer circumference of the handle 14.

In Fig. 2, multiple gaps 22 are depicted at the distal end 20 of the casing 10. Exemplary, four gaps 22 are depicted in Fig. 2. However, only one gap or multiple gaps 22 can be provided at the distal end 20 of the casing 10. Gaps 22 enable air to enter into the casing 10. If the casing 10 is inserted into a heating chamber of an aerosol-generating device as described below, the open distal end 20 of the casing 10 can be blocked by the base of the heating chamber. Then, air can still enter into the casing through the gaps 22. The shape and size of the gaps 22 can be adapted regarding the desired amount of air which can be drawn into the casing over time during removal of the plunger 12 from the casing 10.

Fig. 3 shows the cleaning tool as described with reference to Figs. 1 and 2 in use. In this regard, Fig. 3 additionally shows a heating chamber 24 of an aerosol-generating device 26. In the heating chamber 24, a heating element 28 is arranged. The heating chamber 24 is formed by sidewalls 30 and a base 32. The heating chamber 24 is part of the aerosol generating device 26.

In the left part of Fig. 3, residues 34 of aerosol-forming substrate are depicted adjacent to the base 32 of the heating chamber 24. For removing these residues 34, the casing 10 of the cleaning tool has been inserted into the heating chamber 24. Furthermore, the plunger 12 of the cleaning tool has been inserted into the casing 10. After the insertion of the casing 10 into the heating chamber 24 of the aerosol-generating device 26 and of the plunger 12 into the casing 10, air can only enter into the casing 10 via air inlets 36 of the aerosol-generating device 26. The air inlets 36 are arranged near a mouthpiece end 38 of the aerosol-generating device 26. Alternatively or additionally, air inlets 36 could also be arranged at a different location of the aerosol-generating device 26. As described with reference to Fig. 2, at the distal end 20 of the casing 10, gaps 22 may be provided for facilitating air to enter from the air inlets 36 into the casing 10.

In the right part of Fig. 3, the plunger 12 has been partially removed from the casing 10. Due to this removal, air is sucked from the air inlets 36 and through the gaps 22 into the casing 10. The residues 34 of the aerosol-forming substrate are entrained in this airflow and drawn into the casing 10. After the residues 34 of the aerosol-forming substrate are drawn into the casing 10, the cleaning tool comprising the casing 10 as well as the plunger 12 can be fully removed out of the heating chamber 24 of the aerosol-generating device 26. The residues 34 of the aerosol-forming substrate can then be disposed and a new rod comprising fresh aerosol-forming substrate can be introduced into the heating chamber 24 of the aerosol-generating device 26.

The left part of Fig. 4 shows in more detail the airflow path from the air inlets 36 into the heating chamber 24 of the aerosol-generating device 26. This airflow path is utilized during normal operation of the aerosol-generating device 26, when a rod of aerosol-forming substrate is inserted into the heating chamber 24 of the aerosol-generating device 26 and pierced by the heating element 28. The heating element 28 is then heated to vaporize aerosol-forming substrate for generating aerosol. The aerosol is subsequently delivered towards the mouth of a user by the airflow indicated by the aerosol in Fig. 4. In the right part of Fig. 4, the airflow is depicted by arrows from the air inlet 36 through gaps 22 of the casing 10 into the casing 10. This airflow is generated during removal of the plunger 12 from the casing 10 due to a negative pressure forming in the heating chamber 24.

Fig. 5 shows an embodiment of the plunger 12, in which a recess 40 is provided at a distal end 42 of the plunger 12. The recess 40 is provided such that the plunger 12 can be pushed over the heating element 28 without the heating element 28 damaging the plunger 12. In this embodiment, the plunger 12 can be inserted into the heating chamber 24 of the aerosol-generating device 26 all the way up to the base 32 of the heating chamber 24. In this embodiment, essentially all the air is displaced out of the heating chamber 24, when the casing 10 is inserted into the heating chamber 24 and the plunger 12 is subsequently inserted into the casing 10. An optimized negative pressure can then be created, when the plunger 12 is removed from the casing 10. Again, in the left part of Fig. 5, the plunger 12 is shown fully inserted into the casing 10. In the right part of Fig. 5, the plunger 12 is partly removed from the casing 10 to create the desired suction effect.

Fig. 6 shows an illustration of the operation of the cleaning tool. From top to down, the cleaning tool is provided, wherein the plunger 12 is inserted into the casing 10, but the cleaning tool is not yet inserted into the heating chamber 24 of the aerosol-generating device 26. After that, the cleaning tool is inserted into the heating chamber 24 of the aerosol generating device 26 so that the air in the heating chamber 24 is displaced. At last, the plunger 12 is removed from the casing 10 to create a suction effect for removing residues of aerosol-forming substrate out of the heating chamber 24 of the aerosol-generating device 26. Not shown in Fig. 6, the cleaning tool can subsequently be completely removed from the heating chamber 24 so that new aerosol-forming substrate can be introduced into the heating chamber 24 for normal operation. An on-off button 46 is depicted in Fig. 6 for the purpose of operating the aerosol-generating device 26.

The present invention is not limited by the described embodiments. The skilled person understands that the described features can be combined with each other within the scope of the invention.

Claims

1 . Cleaning tool for cleaning an aerosol-generating device, wherein the aerosol generating device comprises a heating chamber and a heating element arranged in the heating chamber, wherein the cleaning tool comprises a hollow casing and a plunger, wherein the casing is configured to be inserted into the heating chamber, and wherein the plunger is configured to be movably and sealingly inserted into the casing.

2. A cleaning tool according to claim 1 , wherein the casing and the plunger are configured cylindrical.

3. A cleaning tool according to claim 1 or 2, wherein the cleaning tool further comprises a handle, which is connected with the plunger, wherein the handle preferably comprises a structured surface to facilitate gripping of the handle by a user.

4. A cleaning tool according to claim 3, wherein the handle has a hollow or porous structure and is configured elastically compressible to increase the suction effect during extraction of the plunger.

5. A cleaning tool according to one of the proceeding claims, wherein the casing comprises at least one gap at the distal end of the casing, and wherein the gap is configured to allow air to enter from the side of the casing into the casing, when the casing contacts the base of the heating chamber.

6. A cleaning tool according to one of the proceeding claims, wherein the plunger comprises a recess, and wherein the recess is configured such that the plunger can be inserted into the heating chamber over the heating element.

7. A cleaning tool according to one of the proceeding claims, wherein the plunger is configured to reach to the base of the heating chamber, when the plunger is inserted into the heating chamber.

8. A cleaning tool according to claim 7, wherein the plunger comprises a roughened surface at the end of the plunger which contacts the base of the heating chamber, when the plunger is inserted into the heating chamber.

9. A cleaning tool according to one of the proceeding claims, wherein the casing is configured to have the same outer diameter as the inner diameter of the heating chamber so that essentially no air can flow between the casing and the inner sidewalls of the heating chamber, when the casing has been inserted into the heating chamber.

10. A cleaning tool according to claim 9, wherein the outer surface of the casing is roughened so that residues are scraped of the inner wall of the heating chamber, when the casing is inserted into the heating chamber.

1 1. A cleaning tool according to one of the proceeding claims, wherein the casing or the plunger or the casing and the plunger comprise a sealing element, wherein the sealing element is configured to prevent air from flowing between the casing and the plunger.

12. Aerosol-generating device and cleaning tool according to one of the proceeding claims for cleaning the aerosol-generating device, wherein the aerosol generating device comprises a heating chamber and a heating element arranged in the heating chamber, wherein the casing of the cleaning tool is configured to be inserted into the heating chamber, and wherein the plunger of the cleaning tool is configured to be movably and sealingly inserted into the casing.

13. Aerosol-generating device and cleaning tool according to claim 12, wherein the aerosol-generating device comprises at least one air inlet, and wherein the casing comprises at least one gap at the distal end of the casing, and wherein the gap is configured to allow air to enter from the air inlet of the aerosol-generating device into the casing, when the casing contacts the base of the heating chamber.

14. Method for cleaning an aerosol-generating device with a cleaning tool, wherein the aerosol-generating device comprises a heating chamber and a heating element arranged in the heating chamber, wherein the cleaning tool comprises a hollow casing and a plunger, wherein the plunger is configured to be movably and sealingly inserted into the casing, wherein the method comprises the steps of:

inserting the casing into the heating chamber;

inserting the plunger into the casing; and

extracting the plunger out of the casing to generate a suction effect.

15. Method according to claim 14, wherein the cleaning tool further comprises a handle, which is connected with the plunger, wherein the handle has a hollow or porous structure and is configured elastically compressible, and wherein the method comprises the further step, during the insertion of the plunger into the casing, of compressing the handle to increase the suction effect during extraction of the plunger.