Patent Application
20230301355
The present invention relates to a liquid sump for a heater in a capsule for an electronic cigarette.
Electronic cigarettes are an alternative to conventional cigarettes. Instead of generating a combustion smoke, they vaporize a liquid, which can be inhaled by a user. The liquid typically comprises an aerosol-forming substance, such as glycerin or propylene glycol that creates the vapor. Other common substances in the liquid are nicotine and various flavorings.
The electronic cigarette is a hand-held inhaler system, comprising a mouthpiece section, a liquid store, and a power supply unit. Vaporization is achieved by a vaporizer or heater unit which typically comprises a heating element in the form of a heating coil and a fluid transfer element, such as a wick, arranged to transfer fluid from the liquid store to the heating element. Vaporization occurs when the heater heats up the liquid in the fluid transfer element until the liquid is transformed into vapor. The vapor can then be inhaled via an air outlet in the mouthpiece.
The electronic cigarette may comprise a capsule seating which is configured to receive disposable consumables in the form of capsules. Capsules comprising the liquid store and the vaporizer are often referred to as “cartomizers”. In this case, the vaporizer of the cartomizer is connected to the power supply unit when received in the capsule seating of the power supply unit such that electricity can be supplied to the heater of the cartomizer to heat the liquid to generate the vapor. Often some form of mechanical mechanism is used to retain the capsule in the capsule seating such that it does not fall out and separate from the device.
In order to transfer liquid from the liquid store to the heating element, the wick must be arranged between the liquid store and vaporization chamber such that, when the wick is heated, capillary action transports liquid through the porous structure of the wick from the liquid store to the heating element.
It is an object of the present invention to provide an improved transfer of liquid to the heater.
According to a first aspect there is provided a capsule for an electronic cigarette, the capsule having a first end configured to engage with an electronic cigarette device and a second end arranged as a mouthpiece portion having a vapour outlet. The capsule further comprises a storage reservoir configured to store a liquid to be vaporised. A vaporising chamber is arranged to receive liquid from the storage reservoir. A heating element is housed within the vaporising chamber, the heating element comprising a capillary element configured to vaporise the received liquid and generate a vapour. A vapour flow path extends between the vaporising chamber and the mouthpiece to allow the generated vapour to flow from the vaporising chamber to the mouthpiece. A buffer reservoir in fluid communication with the storage reservoir to allow liquid to flow from the storage reservoir to the buffer reservoir, wherein the buffer reservoir has a fluid capacity that is smaller than a fluid capacity of the storage reservoir. The capillary element is arranged to contact liquid received in the buffer reservoir.
The storage reservoir may be considered as a primary liquid reservoir and the buffer reservoir may be considered as a secondary liquid reservoir. The secondary liquid reservoir is smaller than the primary liquid reservoir. At least part of the heating element, namely the capillary element, is arranged in the buffer reservoir meaning that the heating element is fed liquid to be vaporised indirectly from the storage reservoir. That is to say, liquid to be vaporised stored within the storage reservoir flows into and out of the buffer reservoir before it is received by, and vaporised by, the heating element. In other words, the heating element is fed from a secondary liquid reservoir that in turn is fed by one or more liquid conduits from the primary liquid reservoir. By arranging the capillary element to contact the liquid in the buffer reservoir, the heating element is in substantially constant contact with a volume of liquid, which provides a substantially constant flow of liquid to the heating element. This prevents the heating element from drying out during use of the capsule. The capsule may therefore provide improved feeding of the heating element with liquid, providing a substantially constant flow of liquid to the heating element.
Preferably, the buffer reservoir extends in a direction that is parallel to an extension of the heating element. More preferably, the buffer reservoir and the heating element extend in a direction that is perpendicular to a longitudinal axis of the capsule. The surface area of the heating element in contact with the buffer reservoir is therefore increased compared to arrangements in which the buffer reservoir extends in a direction that is perpendicular to an extension of the heating element. Liquid transfer between the buffer reservoir and the heating element is therefore improved.
The buffer reservoir may be fluidly connected to the storage reservoir by a fluid conduit. The conduit therefore enables fluid to flow between the storage reservoir and the buffer reservoir.
The heating element may comprise a heating surface. Preferably, the buffer reservoir is located adjacent to a surface of the heating element which is substantially opposite to the heating surface. More preferably, the buffer reservoir is located adjacent to the capillary element of the heating element. This may allow for efficient transfer of liquid from the buffer reservoir to the heating element.
In some examples, the heating element, the heating surface, and the capillary element may be integrally formed. That is, the heating element, the heating surface, and the capillary element may all form a single component. The single component may be referred to as the heating element. This may ensure efficient fluid transfer through the heating element by ensuring good fluid communication between the heating surface and the capillary element. A single component may also help reduce the change of leaks between the capillary element and the heating surface. In addition, this may reduce the overall number of components within the capsule which may reduce the complexity of the capsule and reduce manufacturing costs.
The heating surface may be considered a first portion of the heating element and the capillary element may be considered a second portion of the heating element. The first and second portions of the heating element, and therefore the heating surface and the capillary surface may be substantially opposite each other.
The heating element may be formed from a porous material. The heating surface may be formed from a porous material. The capillary element may be formed from a porous material. Preferably the heating element which includes the heating surface and the capillary element may be formed from a porous material. The porous material may be a rigid ceramic. The porous material may facilitate liquid transfer through the heating element, from the capillary element to the heating surface, via capillary action. Preferably, the heating element is arranged between the storage reservoir and the buffer reservoir. The buffer reservoir may therefore be considered as being located underneath the heating element, when the capsule is held vertically in its operative configuration with the mouthpiece being located at the top of the capsule, above the rest of the capsule. In other words, the mouthpiece is at the highest level when the capsule is held vertically in its operative configuration. This arrangement may allow a heating element to be indirectly fed by the storage reservoir in a controlled manner while providing improved liquid availability to the capillary element.
The storage reservoir may be located closer to the mouthpiece than the buffer reservoir. Thus, the storage reservoir may be located above the buffer reservoir when the capsule is held vertically in its operative configuration. This means that liquid can flow from the storage reservoir to the buffer reservoir via the conduit under the action of gravity. The buffer reservoir can therefore be automatically filled by the storage reservoir during use of the capsule.
The buffer reservoir can be located between the first end and the heating element or vaporizing chamber. The storage reservoir can be located between the second end and the heating element or vaporising chamber.
In some examples, at least part of the heating element is located within the buffer reservoir. Preferably, at least part of the capillary element is located within the buffer reservoir. This ensures good fluid communication between the buffer reservoir and the heating element.
The buffer reservoir comprises a substantially constant volume of liquid along the length of the buffer reservoir, wherein the length of the buffer reservoir is adjacent at least one surface of the heating element. In some examples, the buffer reservoir is configured to hold a volume of liquid having a depth of 1 mm or less adjacent to the capillary element. More preferably, the length of the buffer reservoir is adjacent at least one surface of the capillary element. This arrangement may provide an increased contact surface area between the heating element and the buffer reservoir, ensuring optimal transfer of liquid from the buffer reservoir to the heating element.
Preferably, the depth of the liquid in the sump is about 1 mm or less. Preferably, the heating element, and more preferably the capillary element, is supported in the buffer reservoir by at least one spacer. This may ensure that a space, or gap, is created between the heating element and a floor of the buffer reservoir to ensure that liquid is able to flow around the heating element. In some examples, the at least one spacer may comprise at least one rib. Alternatively, the at least one spacer may comprise at least one bump.
The at least one spacer may comprise part of the heating element. Preferably, the at least one spacer comprises part of the capillary element. This may reduce the number of individual components within the capsule.
In some cases, the at least one spacer comprises a wall of the buffer reservoir. The wall may be located substantially opposite to the capillary element. Thus, the wall may be located substantially opposite to the heating element.
The buffer reservoir may be delimited by a holder of the capsule and a seal member. The holder may comprise a sump. In some examples, the sump may be the buffer reservoir. A main function of the sump is to feed liquid to the heater indirectly and with small volumes of fluid. This means that the liquid feed to the heater is more homogeneous. The sump may additionally be arranged to collect liquid which has not been vaporized and recycle this liquid back to the heating element.
In some examples, the buffer reservoir and the vaporizing chamber are separated from each other by the heating element, preferably the capillary element, and the seal member.
Preferably, the storage reservoir is delimited by an outer casing of the capsule, the seal member, and the mouthpiece. The mouthpiece may be located substantially opposite to the seal member.
The vapor flow path may comprises a vapor tube connecting the vaporizing chamber to the mouthpiece. In some cases, the vaporizing chamber is sealed by the seal member. The seal is preferably a fluid seal. This may prevent the flow of vapor and liquid from the storage reservoir to the heating element. The seal may further be arranged to prevent liquid bypassing the capillary element and instead ensuring that liquid from the buffer reservoir is transferred via the capillary element to the heating element. The seal may be further arranged to ensure fluid tight arrangement in the vapor tube, between the storage reservoir and the vapor tube, and between the vapor tube and the buffer reservoir.
Preferably, the capsule further comprises an airflow path extending between an air inlet of the capsule and the vaporising chamber for allowing air to flow into the vaporising chamber. The air inlet may be located on an outer surface of the holder. This provides a convenient entry point for air to enter the capsule.
According to another aspect there is provided an electronic cigarette comprising a main body and a capsule wherein the main body comprises a power supply unit, electrical circuitry, and a capsule seating configured to connect with the capsule, the capsule comprising: a first end configured to engage with the electronic cigarette device and a second end arranged as a mouthpiece portion having a vapour outlet, the capsule further comprising: a storage reservoir configured to store a liquid to be vaporised; a vaporising chamber arranged to receive liquid received from the storage reservoir; a heating element housed within the vaporising chamber, the heating element comprising a capillary element configured to vaporise the received liquid and generate a vapour; a vapour flow path extending between the vaporising chamber and the mouthpiece to allow the generated vapour to flow from the vaporising chamber to the mouthpiece; a buffer reservoir in fluid communication with the storage reservoir to allow liquid to flow from the storage reservoir to the buffer reservoir, wherein the buffer reservoir has a fluid capacity that is smaller than a fluid capacity of the storage reservoir; and wherein the capillary element is arranged to contact liquid received in the buffer reservoir.
There may also be provided an electronic cigarette comprising a capsule according to any of the above described capsules.
Embodiments of the present invention will now be described by wait of example with reference to the accompanying drawings in which:
The upper housing portion 10 includes a storage reservoir 30 arranged to contain a liquid to be vaporised. The lower housing portion 20 includes a vaporising chamber 40, where the vaporising chamber 40 has an air inlet 46 and a vapour outlet 47 as shown in
The fluid transfer element 50 generally takes the form of a capillary-style wick which is configured to transport liquid from the storage reservoir 30 through to the vaporising chamber 40 via capillary action through the wick structure, driven by the evaporation of liquid from the centre of the wick by the heating element 41. Generally, the fluid transfer element has an elongate form which extends across the internal volume of the vaporising chamber 40. In this way, when the upper and lower housing portions are brought together as shown in
The lower housing portion 20 comprises a seal member 80 and a holder 44, as shown in
As can be seen from
As shown, for example, in
As can be seen in
The electrical contact elements 70 provide the additional function of coupling the seal member 80 to the holder 44 of the lower housing portion 20. As shown in
The electrical contact elements 70 are therefore arranged in a substantially U-shaped manner, having a vertically extending portion (i.e. the longitudinally extending portions 71) and two horizontally extending portions (i.e. the base portion 72 and the free ends 71a). It should be noted that vertical and horizontal directions are defined with reference to the capsule when it is held in its operative configuration, as shown in
In this way when the capsule 100 is received in an aerosol generating device, for example a main body of an electronic cigarette, the free ends 71a of the electrical contact elements 70 are exposed through the lower housing portion 20, as shown in
Further details of the heating element 41 and the storage reservoir 30 will now be described.
As mentioned, and with reference to
As shown in
Similarly the upper housing portion 10 includes an outer wall 101 forming an outer boundary of the storage reservoir 30 and a tubular wall which defines the vapour flow path 75 extending between the vaporising chamber 40 and the mouthpiece 5. The vapour flow path 75 may be thought of as a tubular passageway or conduit aligned with the elongate axis of the capsule 100. In other words, the vapour flow path 75 is substantially parallel to a longitudinal axis 110 of the capsule 100, as can be seen in
The vaporisation flow path 70 extends in a direction that is substantially perpendicular to an axial direction (i.e. a longitudinal axis) of the capsule 100. The vaporisation flow path 70 may therefore be thought of as a transversal passageway. This arrangement increases the length of the vaporisation flow path 70 across the heating element 41. The heating element 41 is therefore exposed to a longer vaporisation flow path 70 allowing a more consistent, as well as a greater volume, of vapour to be generated.
As has been mentioned previously, the heating element 41 comprises a capillary type heating element having two ends 42. The heating element 41 includes a capillary element 43 which is arranged to receive the liquid to be vaporised from the storage reservoir 30 and a heating surface 45 which is arranged to vaporise the received liquid. The capillary element 43 therefore carries out the function of the previously described fluid transfer element 50.
As can be seen at least in
The capillary element 43 is arranged opposite to the heating surface 45 of the heating element 41 which is in contact with the air flow. As shown in
The heating surface 45 of the heating element 41 essentially extends in a transversal direction and the air flow through the vaporisation flow path 70 flows in the same direction. As a result of capillary action, the liquid is drawn axially through the capillary element 43 to the heating surface 45. Thus, liquid is drawn through the heating element 41 in a substantially vertical direction whilst air flows through the vaporisation flow path 70 in a transverse direction, when the capsule is oriented vertically with the mouth piece above.
In order to aid transfer of the liquid between the storage reservoir 30 and the heating surface 45, the heating surface 45 and the capillary element 43 are in fluid communication with each other. To facilitate the transfer the heating element 41, including the heating surface 45 and the capillary element 43, is formed from a rigid, porous ceramic, which transfers the liquid via capillary action through the porous structure, driven by the evaporation of liquid by the heating element 41. In other words, the heating surface 45 and the capillary element 43 are both formed from a rigid, porous ceramic. Liquid is therefore transferred via capillary action through the overall porous structure of the heating element 41 from the capillary element 43 to the heating surface 45.
A heater track 41a is positioned on the heating surface 45, between the two ends 42 of the heating element 41. In some examples, the heater track 41a is directly printed onto a ceramic surface of the heating element 41. The heater track 41a vaporises the received liquid which causes the liquid vapour to be generated within the vaporising chamber 40, which then flows along the vaporisation flow path 70 and out of the vaporising chamber 40.
As well as the storage reservoir 30, the capsule 100 also includes a buffer reservoir 90 located within the lower housing portion 20, as illustrated in
The buffer reservoir 90 is formed such that it is able to store a substantially constant volume of liquid along the length of the buffer reservoir 90, wherein the length of the buffer reservoir 90 is in a direction that is perpendicular to a longitudinal axis of the capsule 100. The heating element 41 is arranged between the storage reservoir 30 and the buffer reservoir 90. In other words, the buffer reservoir 90 is located underneath the heating element 41 when the capsule is held vertically in its operative configuration, as illustrated in
In order that the liquid in the buffer reservoir 90 can be vaporised by the heating element 41, the buffer reservoir 90 is located adjacent to the heating element 41, as can be seen in
To further improve the transfer of liquid from the buffer reservoir 90 to the heating surface 45, a portion of the heating element 41 is located within the buffer reservoir 90. The heating element 41, in particular the capillary element 45, is supported in the buffer reservoir 90 by a number of spacers 52, illustrated in
The spacers 52 therefore provide a support function and are constructed so that liquid cannot flow through the spacers 52. The spacers 52 can therefore be thought of as forming part of the wall of the buffer reservoir 90. The wall is located substantially opposite to the heating element 41, in particular substantially opposite to the capillary element 43.
The buffer reservoir 90, or liquid sump 90, therefore provides a secondary reservoir within the capsule 100 wherein the storage reservoir 30 is the primary reservoir. This secondary reservoir is located underneath the heating element, as shown in
Since the capillary element 43 is at least partially located within the buffer reservoir 90, the heating surface 45 of the heating element 41 is indirectly fed liquid to be vaporised from the storage reservoir 30. In other words, liquid to be vaporised stored within the storage reservoir 30 flows into and then out of the buffer reservoir 90 before it is received by the heating element 41. Liquid from the storage reservoir 30 is fed to the buffer reservoir by a side port 54, shown in
As can be seen in
Together with the holder 44, the seal member 80 delimits the buffer reservoir 90, in particular an upper boundary of the buffer reservoir 90, as can be seen in
In addition, the heating surface 43 of the heating element 41 can be thought of as forming part of a surface of the seal member 80. As such, the heating surface 45 of the heating element 41 delimits the vaporizing chamber 40, in particular the lower boundary of the vaporizing chamber 40. The heating surface 45 therefore forms a fluid seal with the seal member 80, preventing the flow of vapor and liquid from the vaporizing chamber 40 to the heating element 41. The vaporizing chamber 40 is therefore sealed by the seal member 80.
As the skilled person will appreciate, the capsule described above, and any of its modifications, can be used as part of an electronic cigarette. For example, an electronic cigarette comprises a main body having a power supply, electrical circuitry, and a capsule seating. The capsule seating of the main body is arranged to engage with and electrically connect with the first end 1 of the capsule described above.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20191173.2 | Aug 2020 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/072232 | 8/10/2021 | WO |
