WO2021105173A1

WO2021105173A1 - Electronic cigarette

Info

Publication number: WO2021105173A1
Application number: PCT/EP2020/083302
Authority: WO
Inventors: Pifa Shen; Zhinan MING
Original assignee: Jt International Sa
Priority date: 2019-11-29
Filing date: 2020-11-25
Publication date: 2021-06-03
Also published as: TW202126198A

Abstract

An electronic cigarette (1) is described which includes a housing (10) comprising an air inlet (17); a vaporiser (60); a pressure sensor (90) configured to activate the vaporiser in response to a sensed change in air pressure; and a pressure sensor housing (80) comprising an internal cavity (81) arranged to hold the pressure sensor. The pressure sensor housing comprises a pressure channel (82) running between the internal cavity and a pressure channel opening (84) on the outer surface of the pressure sensor housing. The pressure channel is arranged to place the pressure sensor in communication with the vaporiser. The pressure sensor housing further comprises a main airflow through channel (83) providing an air flow route between the air inlet and the vaporiser. In this way, because the pressure sensor is housed within a cavity in the pressure sensor housing and because the incoming air flow from the inlet is directed through the main airflow through channel and does not pass over the pressure sensor, the responsiveness of the pressure sensor is increased. In particular, the pressure in the cavity drops rapidly upon user inhalation, triggering the pressure sensor.

Description

ELECTRONIC CIGARETTE

Field of invention

The present invention relates to personal vaporizing devices, such as electronic cigarettes. In particular, the invention relates to an electronic cigarette configured to receive disposable cartridges containing a vaporizable material.

Background

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 vapour. Other common substances in the liquid are nicotine and various flavourings. There are several different types of electronic cigarettes, and in general they can be divided into liquid vaporizers, heated tobacco vaporizers or a combination (i.e. a hybrid device) thereof.

An electronic cigarette is typically a hand-held inhaler system, comprising a mouthpiece portion and a power supply portion. Electronic cigarettes are generally configured to receive disposable cartridges containing a vaporizable material are further provided with a power supply portion and a cartridge seating for accommodating the cartridge and for heating the substrate to produce an inhalable vapour to be drawn through the mouthpiece. One known means of triggering the supply of power to the heater is to use a pressure sensor (sometimes referred to as a “puff-sensor”) to determine when a user starts inhaling at the mouthpiece and switching on the supply of power to the heater in response. The pressure sensor identifies air flow associated with a user inhaling at the mouthpiece by measuring a change in pressure within an internal volume of the device which is in fluidic communication with the mouthpiece.

One known problem with such devices is correctly configuring the air pressure sensor so that it triggers correctly when a user inhales at the mouthpiece but is not triggered by other air flow through the device, such as simply moving the device or replacing the cartridge. Often pressure sensors in known devices lack appropriate responsiveness and do not trigger reliably.

An aim of the present invention is to make progress in solving the above mentioned problems with known devices.

Summary

According to a first aspect of the invention there is provided an electronic cigarette comprising a housing comprising an air inlet; a vaporiser; a pressure sensor configured to activate the vaporiser in response to a sensed change in air pressure; a pressure sensor housing positioned between the air inlet and vaporiser, the pressure sensor housing comprising an internal cavity arranged to hold the pressure sensor; wherein the pressure sensor housing comprises a pressure channel running between the internal cavity and a pressure channel opening on the outer surface of the pressure sensor housing, the pressure channel arranged to place the pressure sensor in communication with the vaporiser, the pressure sensor housing further comprising a main airflow through channel providing an air flow route between the air inlet and the vaporiser.

In this way, because the pressure sensor is housed within a cavity in the pressure sensor housing and because the incoming air flow from the inlet is directed through the main airflow through channel and does not pass over the pressure sensor, the responsiveness of the pressure sensor is increased. In particular, air from the inlet is guided through the main airflow through channel, avoiding the pressure sensor, enclosed in a separate part of the air pressure sensor housing. In this way the pressure in the cavity drops rapidly upon user inhalation, triggering the pressure sensor.

As used herein, the term “inhaler” or “electronic cigarette” may include an electronic cigarette configured to deliver an aerosol to a user, including an aerosol for smoking. An aerosol for smoking may refer to an aerosol with particle sizes of 0.5 - 7 microns. The particle size may be less than 10 or 7 microns. The electronic cigarette may be portable. The term “inhaler” or “electronic cigarette” is also intended to cover “heat not burn” devices which generate an aerosol by heating a material, for example tobacco, sufficiently to release a vapour without burning the material.

Preferably the pressure channel and main airflow through channel are separated within the pressure sensor housing. In this way air flow from the air inlet during inhalation does not pass through the cavity or pressure channel but is diverted around the pressure sensor through the main airflow through channel. Preferably the main airflow through channel runs through the pressure sensor housing from a first side to a second side. The main airflow through channel may be substantially parallel to the pressure channel. In this way, air exiting the main air flow through channel will not enter the pressure channel opening on the outer surface of the pressure sensor housing.

Preferably the pressure sensor housing is positioned between the vaporiser and the air inlet with a first side of the pressure sensor housing facing the vaporiser and a second opposing side of the pressure sensor housing facing the air inlet; wherein the pressure channel opening is on the first side of the pressure sensor housing. By positioning the pressure sensor housing between the air inlet and the vaporiser it is positioned within the air flow route within the electronic cigarette. It therefore may be configured to control the air flow through the device by blocking the parts of the air flow path and only allowing air to pass through the main airflow through channel. By positioning the pressure channel opening on the first side of the pressure sensor housing it is directed at the vaporiser, meaning the change of pressure due to inhalation is more efficiently directed to the pressure sensor and main air flow cannot enter the pressure channel.

Preferably the main airflow through channel runs through the pressure sensor housing from the second side to the first side. In this way, the dimensions of the housing can be appropriately configured to provide the required air flow characteristics. Preferably the pressure sensor housing is configured such that the main airflow channel provides the only air flow route past the pressure sensor housing from the air inlet in the electronic cigarette housing. In particular, preferably this is achieved by arranging the pressure sensor housing such that it forms a seal across the internal volume of the electronic cigarette, i.e. to divide the internal volume between a portion containing the air inlet and a portion containing the vaporiser. The pressure sensor housing may extend between opposing inner surfaces of the housing to form a seal. In some embodiments, the pressure sensor housing may form the seal in combination with other components of the electronic cigarette. For example the sensor housing may extend between the internal components of the device to seal the air flow. In one embodiment the pressure sensor housing extends across the device between one side of the battery and an opposing inner surface of the housing to seal the internal volume of the device.

Preferably the pressure sensor housing comprises an elastic material. Preferably the pressure sensor housing comprises a resilient deformable material. With these materials, the pressure sensor housing may conform to the internal diameter of the housing formed by the inner surface of the housing and/or internal component to form a high quality seal. In one example the pressure sensor housing comprises silicone.

Preferably the vaporiser comprises a vaporiser air inlet wherein the vaporiser air inlet is larger than the housing air inlet. In this way, inhalation at the mouthpiece causes a rapid reduction in pressure as air within the internal volume of the device can exit the device through the vaporiser inlet faster than it can enter the device through the air inlet in housing.

The vaporiser preferably comprises a heating element and a liquid transport element to transport liquid from a liquid store to the heating element to be vaporised. Preferably the vaporiser is provided with a cartridge, i.e. a cartomiser, comprising a liquid store, a liquid transport element, a heating element and a vapour flow path arranged to allow the generated vapour to exit the cartomiser. The electronic cigarette preferably comprises a cartridge seating arranged to receive a removable cartridge, the cartridge seating preferably comprising electrical contacts to contact corresponding contact on the cartridge such that the heating element of the cartridge can be connected to the battery. The vaporiser air inlet may be provided by the air inlet in the cartridge seating which provides an air flow route into a cartridge received in the cartridge seating.

The first cartridge may comprise an aerosol-forming substance such as propylene glycol and/or glycerol and may contain other substances such as nicotine and acids. The liquid L may also comprise flavourings such as tobacco, menthol or other flavours. The mouthpiece may comprise a vapour outlet through which a vapour generated in the first cartridge may be inhaled by a user when the mouthpiece is in the closed position.

The electronic cigarette may further comprise an internal cavity within the housing, the internal cavity positioned between the pressure sensor housing and the vaporiser. In this way, the pressurised airflow exiting the pressure channel opening passes through the internal cavity before reaching the air inlet of the vaporiser.

Preferably the electronic cigarette further comprises an air inlet tube arranged between the air inlet in the housing and the pressure sensor housing wherein the air inlet tube is connected to the main airflow through channel of the pressure sensor housing such that together the air inlet tube and the main airflow through channel provide an air flow route from the air inlet to the vaporiser. The air inlet tube may be a tubular component which extends for at least a portion, preferably the majority, more preferably the entirety of the air flow route between the air inlet in the housing and the pressure sensor housing. The air inlet tube comprises a tubular passage connected to the air inlet at one end and the main airflow through passage of the pressure sensor housing at the other end.

In some embodiments the pressure channel opening is provided on a protruding portion of the pressure sensor housing. In particular the pressure sensor housing may comprise a protruding portion on a second side, facing the air inlet, which extends away from the second surface of the pressure sensor housing. The protruding portion may interface with other components of the device to provide a tight seal. For example the protruding portion of the sensor housing may be configured to interface with the air inlet tube to provide a sealed air flow route between the air inlet and the pressure sensor housing. In some embodiments the protruding portion may be sleeved on or within the air inlet tube. The protruding portion may comprise one or more circumferential ridges to improve the seal.

Preferably the pressure sensor comprises a planar pressure sensing surface and the pressure channel is arranged substantially normal to the plane of the pressure sensing surface. In particular the pressure sensor may comprise a pressure sensing membrane or diaphragm configured to move under an applied pressure, where the movement can be sensed by, for example, piezoelectric, piezoresistive, capacitive or electromagnetic sensing elements. By arranging the pressure channel substantially normal to the plane of the pressure sensing surface the movement of the pressure sensing surface is increased for a given pressure, meaning the pressure sensor is more sensitive to changes in pressure.

Preferably the main air flow through channel is arranged substantially normal to the plane of the pressure sensing surface. This minimises the amount of air passing through the main airflow through channel which reaches the pressure sensor.

Preferably the pressure sensor housing comprises one or more lead wire through holes running through the housing for connections between the electrical components of the device to pass through the pressure sensor housing, wherein the holes comprise a film sealing one side of the lead wire through holes to prevent air passing through the lead wire through holes. In this way, connections may be made between components sealed on either side of the pressure sensor housing whilst maintaining the seal with the pressure sensor housing. In particular, by providing a film sealing one side of the lead wire through holes, the film is only pierces upon making the connections during assembly of the device and the film is preferably elastic such that it seals around the wires to maintain the seal across the pressure sensor housing.

Preferably the electronic cigarette further comprises a PCB (printed circuit board) wherein the plane of the PCB is arranged substantially normal to the pressure sensing surface of the pressure sensor.

In some embodiments the electronic cigarette may further include an air channel plug arranged within the outer housing sleeve between the closed end of the outer housing comprising the air inlet and the pressure sensor housing, the air channel plug comprising: an air channel arranged to provide at least a portion of an air flow route connecting the air inlet to the cartridge seating. Preferably the air channel plug is arranged to provide a seal across the internal volume of the housing such that air entering the air inlet is restricted to passing through the air channel to the pressure sensor housing. In this way the air flow route into the device can be better defined to provide a more constant pressure drop upon inhalation into the device, thus allowing the heater to be more reliably triggered.

Preferably the air channel plug extends from an inner surface of the housing at the air inlet to the pressure sensor housing and the air channel connects the air inlet with the main airflow channel of the pressure sensor housing.

The air channel plug is preferably a solid piece of material positioned within the outer housing at the closed end of the outer housing sleeve. The air channel plug preferably fills the internal volume of the outer housing sleeve from the closed end to a certain position along the length of the outer housing sleeve. The air channel is preferably provided through the air channel plug to define the air flow route into the device.

Preferably the air channel plug extends from the closed end of the outer housing sleeve over more than 25% of the length of the housing sleeve measured from the closed end to the open end. This provides particularly increased protection to the electronic components of the electronic cigarette. This also allows for the air channel to provide an air flow route to the air inlet of the cartridge seating. Preferably the air channel plug comprises a resilient deformable material, for example an elastic material such as rubber or silicone. This allows it to conform to the inner surfaces of the outer housing and the internal components of the electronic cigarette.

In some embodiments the electronic cigarette may comprise an outer housing sleeve having an open end and a closed end; a functional insert comprising electrical components; wherein the functional insert is arranged to be introduced through the open end of the outer housing sleeve and is held within the outer housing sleeve. By grouping the functional electronic components together on the functional insert and by providing the device housing in the form of a sleeve, the assembly process is simplified as the functional components can be assembled in a first assembly step and then subsequently sleeved within the outer housing in a single step, thus reducing the complexity of the assembly procedure. It is also more straightforward to reproducibly assemble the functional components in the correct arrangement when this carried out on a separate integral structure before sleeving this within the housing, thus reducing variation in the performance of the electronic cigarette.

In these embodiments, the functional insert preferably includes the pressure sensor and pressure sensor housing such that these components may be assembled and connected appropriately before being inserted into the housing. The term “functional insert” refers to a component which comprises the functional components of the device, that is, the components associated with the functional of producing an aerosol for inhalation, in particular the electrical components. The functional insert is preferably an integral component to which the functional elements of the electronic cigarette are attached or housed within.

The outer housing sleeve preferably comprises a hollow tubular housing with an open end, through which the functional insert may be inserted into the device during assembly, and a closed end. The closed end is “closed” in that the insert can only be introduced through the open end but the closed end may comprises one or more openings, for example to accommodate an air inlet and/or charging port.

The functional insert preferably comprises a cartridge seating for receiving a removable cartridge; a battery; and electronic circuitry for supplying power from the battery to a cartridge received in the cartridge seating during use. These components require careful assembly and relative positioning so by providing them in the form of an integral functional insert provides significant reduction in the complexity of manufacture. The functional insert preferably comprises one or more of a PCB, the airflow sensor for sensing inhalation at the mouthpiece so that power provision to a cartridge in the cartridge seating may be initiated, a charging port for connecting the battery to mains power, a connection mechanism for connecting to a mouthpiece.

Preferably the electronic cigarette further comprises: a mouthpiece portion (also referred to as the mouthpiece), the mouthpiece portion being moveably connected the outer housing sleeve or functional insert by a connection mechanism; wherein the connection mechanism is configured to enable the mouthpiece portion to move relative to the functional insert or housing between: a closed position in which the first cartridge seating is enclosed in the electronic cigarette; and an open position in which the first cartridge seating is exposed such that a first cartridge can be received, while the mouthpiece portion remains connected to the functional insert or outer housing sleeve by the connection mechanism.

Preferably, the mouthpiece portion comprises a second cartridge seating configured to receive a second cartridge. Accordingly the characteristics of the generated vapour may be formed as a combination of two vapours generated from the respective cartridges such that vapour characteristics can be adjusted and enhanced, thereby improving the user experience. Preferably the second cartridge is replaceable. The second cartridge may be inserted into the second cartridge seating through an opening in the second cartridge seating. The second cartridge seating may be provided by a mouthpiece channel which runs through the mouthpiece from a vapour outlet, through which vapour is inhaled, to an internal opening in the second contacting surface which is adjacent to the first cartridge seating when the mouthpiece is in the closed position. The opening in the cartridge seating may be provided by the vapour outlet in the mouthpiece portion such that the second cartridge may be inserted when the mouthpiece is in a closed position. The second cartridge may be configured such that it provides a mouthpiece through which a user inhales the generated vapour. In particular, when the second cartridge is inserted a portion of the second cartridge may protrude from the mouthpiece portion providing a mouthpiece.

The second cartridge may also comprise an aerosol-forming substance such as tobacco, propylene glycol and/or glycerol and may contain other substances such as nicotine and acids. The liquid may also comprise flavourings such as tobacco, menthol or other flavours. Preferably the second cartridge comprises a tobacco substrate. In this way, the vapour generated in the first cartridge passes through the tobacco substrate, picking up compounds which provide the generated vapour with an improved flavour and nicotine content, enhancing the user experience.

Preferably the electronic cigarette is arranged such that, when the mouthpiece portion is brought to the closed position, a vapour flow path is created between the first cartridge and the second cartridge. In particular, when a first cartridge is received in the first cartridge seating, a second cartridge is received in the second cartridge seating and the mouthpiece is brought to the closed position a fluidic connection is formed between the first cartridge, the second cartridge and the mouthpiece. In this way, a vapour generated in the first cartridge, flows through the second cartridge which imparts new characteristics on the generated vapour before it is inhaled by the user through the mouthpiece. A wide range of different vapour characteristics may therefore be provided, enhancing the user experience and the inhaled vapour may have improved flavour or active ingredient content.

Preferably the hinge mechanism, connecting the mouthpiece to the first end of the functional insert, comprises an internal lever, the lever being fixedly connected at one end to the mouthpiece portion and rotatably connected at the opposite end in a receiving portion located in the functional insert. By providing an internal hinge mechanism, the mechanism is protected within the functional insert improving the lifetime of the mechanism and the external shape of the device may be uniform, improving the usability.

Preferably the lever is L-shaped and the lever connects a central point in the mouthpiece portion to a point near an edge of the functional insert. This allows an internal lever to provide an increased displacement of the mouthpiece portion with a smaller movement of the lever. In particular, the lever may be connected near a radial extremity of the first contact surface and nearer the centre of the second contacting surface.

In a further aspect of the invention there is provided a kit comprising: an electronic cigarette and a removable cartridge wherein the electronic cigarette comprises: a housing comprising an air inlet; a cartridge seating configured to receive a replaceable cartridge comprising a vaporiser; a pressure sensor configured to activate the vaporiser in response to a sensed change in air pressure; a pressure sensor housing comprising an internal cavity arranged to hold the pressure sensor; wherein the pressure sensor housing comprises a pressure channel running between the internal cavity and a pressure channel opening on the outer surface of the pressure sensor housing, the pressure channel arranged to place the pressure sensor in communication with the vaporiser, the pressure sensor housing further comprising a main airflow through channel providing an air flow route between the air inlet and the vaporiser. In a further aspect of the invention there is provided a first cartridge configured for use with electronic cigarette as defined in any of the appended claims.

Brief description of the drawings

The invention will now be described with reference to the appended drawings, which by way of example illustrate embodiments of the present invention and in which like features are denoted with the same reference numerals, and wherein:

Figure 1 A and 1 B respectively illustrate an outer view and cross-section view or an electronic cigarette according to the present invention; Figure 2 illustrates a portion of an electronic cigarette according to the present invention; Figure 3 schematically illustrates a portion of an electronic cigarette according to the present invention;

Figures 4A and 4B schematically illustrate views of a pressure sensor housing according to the invention;

Figured 5 schematically illustrates a pressure sensor housing according to the invention;

Figure 6 schematically illustrates an electronic cigarette according to the present invention.

Detailed description

Figures 1 to 3 schematically illustrate an electronic cigarette 1 according to the present invention. The electronic cigarette 1 includes a housing 10 comprising an air inlet 17 and, as shown in the cross sectional figures 1 B, 2 and 3, a vaporizer assembly 60, a pressure sensor 90 and a pressure sensor housing 80. The pressure sensor 90 is configured to activate the vaporizer 60 in response to a sensed change in air pressure. The pressure sensor housing 80 comprises an internal cavity 81 arranged to hold the pressure sensor 90. The pressure sensor housing 80 further includes a pressure channel 82 connecting the internal cavity 81 to a pressure channel opening 84 on the outer surface of the pressure sensor housing 80. The pressure channel 82 is arranged to place the pressure sensor 90 in communication with the vaporizer 60 and the pressure sensor housing 80 further comprises a main air flow through channel 83 providing an air flow route between the air inlet 17 in the housing 10 and the vaporizer 60.

By providing the air pressure sensor 90 within an internal cavity 81 of the pressure sensor housing 80 and connecting this fluidically with the vaporizer 60 using the pressure channel 82, the pressure sensor 90 is protected from the main air flow route which is directed through the main air flow through channel 83 within the sensor housing 80. The pressure sensor housing 80 also fills a proportion of the internal volume of the electronic cigarette 1 such that the pressure sensor is held with a reduced volume within the cavity 81 , and therefore is more responsive to a user’s inhalation as this more significantly changes the pressure within the cavity 81.

The vaporiser 60 may be provided by any known means to vaporise a liquid. In this example the vaporizer 60 comprises a heating element and a liquid transport element (not shown) configured to transport aerosol generating liquid from a liquid store to the heating element for vaporization. In the example shown in the figures, the vaporizer is provided within a replaceable cartridge 40 (i.e. a “cartomizer") which includes a heating element, liquid store and liquid transport element in addition to a vapour channel configured to provide a vapour flow route from the heating element to an air outlet for inhalation by a user.

As shown in Figures 1 B and 2, the electronic cigarette 1 includes a first cartridge seating 21 arranged to receive the replaceable cartridge 40 and connect electrical contacts on the replaceable cartridge 40 with the battery 22 within the body of the electronic cigarette 1. By selectively providing power from the battery 22 to the heating element of the removable cartridge 40 received in the first cartridge seating 21 , a vaporisable liquid held within the cartridge 40 is vaporised and transported through a vapour passage 42 out of the cartridge 40 and cartridge seating 21 for inhalation through the mouthpiece portion 30. In the example of the figures, the electronic cigarette 1 further includes a second cartridge seating 32 within the mouthpiece portion 30 where the second cartridge seating 32 is configured to receive a second cartridge 41 which is arranged such that the vapour generated within the first cartridge 40 passes through the second cartridge to be inhaled by a user. The second cartridge 41 is received in the cartridge seating 32 such that a portion of the second cartridge 41 protrudes from the mouthpiece portion 30, providing the mouthpiece around which the user may place their lips in order to inhale the vapour. The second cartridge is entirely optional and other examples may use only a single cartridge with no implications for the functioning of the other components of the device, described herein.

The supply of current from the battery 22 to the heating element of the removable cartridge 40 received in the first cartridge seating 21 is activated when the pressure sensor 90 senses a drop in pressure within the device 1 . The pressure sensor may be provided by any appropriate sensor which is configured to sense a change in pressure in the internal volume of the electronic cigarette 1 to an appropriate degree of accuracy in order to trigger the power supply to the heating element. The pressure sensor 90 may comprise a deformable membrane 91 which distorts under an applied pressure where the distortion of the membrane can be measured in order to determine a change in pressure communicated to the membrane.

In the example of Figure 2, the membrane is a planar membrane 91 substantially parallel to a top surface of the pressure sensor 90. The pressure sensitive membrane 91 is in communication with the air flow route to the mouthpiece via pressure channel 81 through the pressure sensor housing 80. As shown in Figures, the air pressure sensor 90 is arranged such that membrane 91 has space within the internal cavity 81 directly above the membrane, allowing it to upwardly deform under a negative pressure. That is, the pressure sensor 90 is positioned such that a proportion of the volume of the internal cavity 81 remains unoccupied above the pressure sensor membrane 91 allowing it to bend upwards.

In known devices generally the interior space of the device is quite large and there is a large quantity of air that enters through holes in the casing, for example through the charging port which can result in a lack of responsiveness of the air flow sensor. In the present invention, the air pressure sensor housing 80 provides a number of features which reduce this effect and provide a more reliable activation of the pressure sensor 90.

Firstly, the pressure sensor housing 80 divides the main air flow through channel 83 from the pressure sensor cavity 81 and pressure channel 82. In particular, the pressure sensor cavity 81 is provided centrally within the pressure sensor housing and is connected to an outer surface only by the pressure channel 82. As shown in Figure 2, the pressure channel 82 connects to a pressure channel opening 84 on a first side 85 of the pressure sensor housing 80 which faces the vaporizer assembly within the first cartridge 40 within the first cartridge seating 21. A change in pressure due to a user inhaling at the mouthpiece 41 of the second cartridge 41 shown in Figure 1 B is therefore communicated to the pressure sensor 19 by a vapour flow route comprising the vapour channel 43 in the second cartridge 41 , the vapour channel 42 in the first cartridge 40 the inlet 61 to the first cartridge seating 21 and finally through the air pressure channel 82 to the pressure sensor 90 received in the pressure sensor cavity 81. The pressure sensor cavity 81 is preferably sealed on the opposing second side 86 of the pressure sensor housing 80 such that the pressure sensor cavity 81 is a relatively small volume and therefore experiences more significant pressure changes for a given volume of an air flow out of the device 1.

The main air flow through channel 83 provides an air flow route between the second side 86 and the first side 85 of the pressure sensor housing 80. This main air flow through channel 83 is divided from the pressure sensor cavity 81 within the pressure sensor housing 80 such that no air passes over the air flow sensor from the inlet 17. This arrangement provides significantly enhanced sensitivity of the air pressure sensor 90. As shown by the arrows indicating the air flow route in Figure 3, when a user inhales at the mouthpiece 30, air enters the housing 10 through the inlet 17 at the base 12 of the device 1 , passes in to the device and through the main air flow through channel 83 of the pressure sensor housing 80. The air flow then passes into the vaporiser inlet 61 at the base of the first cartridge seating 21.

The air flow sensor housing preferably extends across at least a portion of the internal volume of the housing 10 to prevent air passing around the pressure sensor housing 80 and the internal walls of the housing 10. In some embodiments the air pressure sensor housing 80 may extend across the full cross section of the internal volume of the device. In other examples, such as that pictured in Figure 2, the air flow sensor housing 80 extends between the internal components of the device 1 to seal the air flow route through the device 1. In the example of Figure 2 the pressure sensor housing 80 extends between the battery 22 and an opposing surface of the inner housing 10 walls to seal this portion of the internal volume of the device 1.

Figures 4A and 4B show the pressure sensor housing 80 from two different views. The air pressure sensor housing 80 is preferably made of an elastic material such as silicone which can conform to the internal surfaces of the components and housing 10 to provide a seal across the air flow route into the internal volume of the device 1. As shown in Figure 4, the air pressure sensor housing 80 is substantially disc shaped with a first side 85 containing the opening 84 to the pressure channel 82 where the first side 85 is arranged to be directed towards the vaporizer 60. The opposing second side 86 of the housing 80 is arranged to face the air inlet 17 in the device housing 10. The second side 86 includes the opening to the main air flow through channel 83 which may be provided on a protruding portion 87 of the housing 80 which extends towards the air inlet 17 when appropriately oriented within the device 1 .

The electronic cigarette may also comprise an air inlet tube 18 which is positioned between the air inlet 17 and the pressure sensor housing 80 and arranged to provide at least a portion of the airflow route between the air inlet 17 and the main air flow through channel 83. As shown in Figures 1 B, 2 and 3 the air inlet tube connects the air inlet with the main airflow through channel 83 of the pressure sensor housing 80. In the examples of the figures, the protruding portion 87 of the sensor housing 80 is partially sleeved within the air inlet tube 18 to provide a sealed air flow passage between the air inlet 17 and the main airflow through passage 83. In this way, the air flow does not pass over the internal components of the devices such as the battery 22 and PCB 220, reducing the risk of contamination of the air flow and reducing the volume of the air flow channel between the air inlet 17 and the vaporiser, leading to a quicker drop in pressure during inhalation and an associated faster response of the air pressure sensor 90. The protruding portion 87 of the housing which includes the main air flow through channel 83 may additionally comprise one or more circumferential ridges 88 which are arranged to engage within the air inlet tube 18 within the housing 10 to provide a sealed connection.

As shown in Figure 5, the pressure sensor housing 80 may include one or more lead wire through holes 89 which extend from the first, upper, side 85 of the housing 80 to the second, lower, side 86 of the housing 80. The lead wire through holes 89 include a larger diameter opening 891 on the first side of the housing and a reduced diameter 892 second opening on the second side 86 of the housing 80. The reduced diameter second opening 892 may be sealed with a film 893 or thin layer of housing material prior to insertion in the device 1. Then lead wires may be pushed through the lead wire through holes 89 when connecting the components of the device such that the film 893 at the second opening 892 is pierce to provide a seal around lead wires which pass through the lead wire through holes 89 to prevent air flow at these points through the sensor housing 80.

As shown in Figure 3 this allows the vaporizer 60 to be connected to components below the sensor housing 80. Figure 3 shows how connections 221 are provided between the vaporizer 60 provided on the upper side of the sensor housing 80 and the PCB 220 provided on the lower side of the housing 80. In this way, connections may be made between the components positioned above the pressure sensor housing 80 and components below the pressure sensor housing 80 whilst maintaining the seal across the internal volume of the electronic cigarette 1. The film 893 is preferably an elastic material which engages with the leas wires after being pierced to provide the seal.

To further improve the sensitivity of the air pressure sensor 90, the air inlets can be appropriately configured to improve responsiveness. In particular, the air inlet 61 to the vaporizer 60 is preferably larger than the air inlet 17 into the housing 10 of the device 1. In this way, when a user inhales at the mouthpiece air within the housing 10 is more rapidly removed than it is replaced through the inlet 17. This results in a rapid drop in pressure and accordingly provides a more responsive pressure sensor 90. When the appropriate sizing of the air inlet is combined with the other features of the pressure sensor housing 80, in particular a small internal cavity with a pressure channel 82 which is separated by the housing 80 from the main air flow through channel 83, significant improvement to the reliability of the sensor 90 can be achieved. Furthermore, the electronic cigarette 1 may further comprise an internal cavity within the housing 10 positioned between the pressure sensor housing 80 and the vaporizer 60. In this way, the pressurised air flow needs to exit the pressure channel 82 and pass through the internal cavity 19 before reaching the inlet 61 to the cartridge seating 21 .

As described above, the pressure sensor 90 is substantially planar and comprises a planar pressure sensing surface 91 in the form of a membrane which is deformed under the application of pressure changes which can be senses by electronic elements within the pressure sensor 90. As shown in Figure 2, the pressure channel is arranged substantially normal to the plane of the pressure sensing surface 91. This communicates pressure changes to the pressure sensing surface 91 most effectively to provide increased sensitivity of the pressure sensor 90. The main air flow through channel 83 is also arranged substantially normal to the plane of the pressure sensing surface such that air flow through the air flow channel 83 is not directed across the opening 84 to the pressure channel 82 where it may be communicated to the pressure sensor 90.

An alternative example of an electronic cigarette 1 according to the present invention is schematically illustrated in Figure 6. As with the previously described examples, the electronic cigarette 1 comprises a pressure sensor housing 240 positioned between a vaporizer assembly 60 and an air inlet 117 on the closed end 102 of the housing 100. The example of Figure 6 differs from the previously described electronic cigarettes 1 in that it further includes an air channel plug 210 which is arranged within the outer housing sleeve 100 between the closed end 102 of the outer housing sleeve 100 and the functional insert 200. The air channel plug 300 comprises an air channel 310 which provides at least a portion of an air flow route connecting the air inlet 117 of the outer housing 100 to the cartridge seating 221 . The air channel plug 300 is a plug of material which occupies a portion of the internal volume of the outer housing sleeve 100 at the first end 102. In particular the air channel plug 300 may comprise a piece of material which substantially fills the internal volume of the closed end 102 of the outer housing sleeve 100 and extends a certain length L1 from the closed end 102 towards the open end 101 .

The air channel plug 300 serves a number of purposes. It firstly acts to only allow air flow into the device 1 through a defined air flow passage way 310. In some devices which do not include such an air channel plug, air can enter the device through openings in the casing, for example the charging port, which reduces the pressure drop when inhaling through the mouthpiece and can have implications for aerosol generation and for the correct triggering of the pressure sensor 90 to activate the device 1. Furthermore, the air channel plug 300 can act to protect the electrical components of the device by preventing contact between these components and the closed end within the outer housing sleeve 100, which can minimise damage, for example if the electronic cigarette is dropped.

By managing the air flow route into the device through the air channel 310 within the air channel plug 300 it can be ensured that the air flow pressure exerted from inhaling at the mouthpiece is directed to the sensor 242 and the sensor 242 is not triggered by air flow through the openings at the base of the device 1 over the air flow sensor 242. It also reduces the free internal volume of the device which can lead to a lack of responsiveness of the sensor 242. The air channel plug 300 is preferably made of a resilient deformable material such as an elastic material (e.g. silicone) which deforms to the shape of the internal volume within the outer housing 100 and provides shock absorption within the device 1 to protect the electrical components of the device. The air channel plug 300 also provides a seal across the cross section of the internal volume of the outer housing sleeve 100 such that air flow into the outer housing sleeve 100 is restricted other than through passage via the air channel 310.

The air channel plug 300 preferably extends over a length from the closed end 102 of the outer housing sleeve towards the open end which corresponds to more than 25% of the total length of the housing, as measured from the closed end 102 to the open end 101 . This provides sufficient shock absorption to prevent damage from accidental dropping of the device and also the advantage that it is possible to properly position the cartridge seating 221 and arrange the cartridge air inlet within the device.

The air channel 310 is preferably arranged such that it passes through the air channel plug 300, that is, it passes centrally through the mass of deformable elastomeric material. The air channel 310 and the air channel plug 300 which houses it may extend upwards from the closed end of the device sufficiently to engage with the main airflow through channel 241 in the pressure sensor housing 240.

As described above the electronic components may be provided in the form of an integral functional insert 200 arranged to be inserted through an open end of a tubular housing sleeve 100 and secured within the device 1 . A secure connection between the functional insert 200 and the air channel plug 300 may be achieved in a number of different ways. In the example of Figure 6, the PCB 220 extends along the elongate axis of the device 1 from its connection with the battery 222 and cartridge seating 221 towards the second base end 102, where it engages with a slot 301 provided in the air channel plug 300. In this way, the PCB 220, which is connected to the electronic components of the functional insert 200, extends along the elongate axis downwards towards the closed end of the housing 100 and extends within a slot 301 provided in the air channel plug 300 which retains the PCB providing a mechanical connection between the functional insert 200 and the air channel plug 300.

The electronic cigarette 1 may also include a charging port 302 allowing the device to be connected to a mains power supply to charge the battery 222. In the example of Figure 6 the charging port 302 is provided within the air channel plug 300 and is connected to the electronic components of the functional insert 200 by electrical circuitry 303. This provides another connection between the air channel plug 300 and the functional insert 200. In particular, the charging port 302 is generally a metallic aperture arranged to receive a mains charger and may be positioned wholly or partially within the elastomeric material of the air channel plug 300 with the open end of the charging port extending out of the base such that it protrudes sufficiently to align with an aperture at the closed end 102 of the outer housing sleeve 100. The charging port 302 may be connected to the PCB 220 within the slot 301 within the air channel plug 300. In this way, a mechanical and electrical connection is provided between the functional insert 200 and the air channel plug 300 using the existing features of these components, i.e. without requiring any additional securing components.

Figure 6 further illustrates how the air flow sensor housing 240, which houses the air flow sensor 242, connects to the air channel plug 300. The internal cavity 243 which holds the air flow sensor is in fluidic communication with the first cartridge seating 221 such that the air flow sensor is triggered when the user inhales at the mouthpiece 30. As above, the air flow sensor 242 is also connected to the power supply to turn on the power to the heater from the battery when a change in air pressure, corresponding to a user inhaling at the device, is detected. As shown in Figure 8, the air flow sensor housing 240 also includes a separate air flow through channel 241 which is not in connection with the internal chamber. The air flow through channel 241 is connected to the air flow passage 310 within the air channel plug 300. Together therefore, the air flow through channel 241 of the air flow sensor housing 240 and the air channel 310 of the air channel plug provide the air flow route from the air inlet 117 in the outer housing sleeve 100 to the cartridge seating 221 .

The air flow sensor housing 240 may also comprise a similar material to the air channel plug 300 such as a resilient deformable material such as an elastic material (e.g. silicone). Together, the air channel plug 300 and the air flow sensor housing 240 provide the air flow route from the inlet 117 to the cartridge seating 221 and ensure that this does not pass over the air flow sensor 242. This prevents the air flow sensor 242 being triggered via air flow through the inlet 117 but only via the reduction in air pressure from the user inhaling at the mouthpiece which is delivered directly to the internal chamber of the airflow sensor housing. The air flow route from the inlet 117 in the outer housing shell 100 to the cartridge seating 221 is illustrated with a series of arrows A. In this example, the air channel plug 300 extends from the closed end 102 of the housing upwards to meet the air flow sensor housing 240. Furthermore, the air flow channel 310 provided in the air channel plug 300 directly connects the air inlet 117 in the outer housing sleeve 100 to the air flow through channel 241 in the air flow sensor housing 240. Therefore, together the air channel plug 300 and the air flow sensor housing 240 form an air flow path from the air inlet to the cartridge seating 221 . In particular, as shown by the arrows A, the air enters the air inlet 117 passes through the air flow channel 310 of the air channel plug 300 enters the air flow through channel 241 of the air flow sensor housing 240 and is directed into the base of the cartridge seating 221 to extract the vapour generated therein and carry it to the mouthpiece 30. Because there is no direct air flow from the inlet over the air flow sensor, the air flow sensor is more sensitive to air flow pressure changes due to inhalation at the mouthpiece.

Claims

1. An electronic cigarette comprising a housing comprising an air inlet; a vaporiser; a pressure sensor configured to activate the vaporiser in response to a sensed change in air pressure; a pressure sensor housing positioned between the air inlet and vaporiser, the pressure sensor housing comprising an internal cavity arranged to hold the pressure sensor; wherein the pressure sensor housing comprises a pressure channel running between the internal cavity and a pressure channel opening on the outer surface of the pressure sensor housing, the pressure channel arranged to place the pressure sensor in communication with the vaporiser; the pressure sensor housing further comprising: a main airflow through channel providing an air flow route between the air inlet and the vaporiser.

2. The electronic cigarette of claim 1 wherein the pressure channel and main airflow through channel are separated within the pressure sensor housing.

3. The electronic cigarette of claim 1 or claim 2 wherein a first side of the pressure sensor housing faces the vaporiser and a second opposing side of the pressure sensor housing faces the air inlet; wherein the pressure channel opening is on the first side of the pressure sensor housing.

4. The electronic cigarette of claim 3 wherein the main airflow through channel runs through the pressure sensor housing from the second side to the first side.

5. The electronic cigarette of claim 3 or claim 4 wherein the pressure sensor housing forms a seal across the internal volume of the electronic cigarette between the inlet and the vaporiser.

6. The electronic cigarette of any preceding claim wherein the pressure sensor housing comprises an elastic material.

7. The electronic cigarette of any preceding claim wherein the vaporiser comprises a vaporiser air inlet wherein the vaporiser air inlet is larger than the housing air inlet.

8. The electronic cigarette of any preceding claim further comprising an internal cavity within the housing, the internal cavity positioned between the pressure sensor housing and the vaporiser.

9. The electronic cigarette of any preceding claim wherein the pressure sensor comprises a planar pressure sensing surface and the pressure channel is arranged substantially normal to the plane of the pressure sensing surface.

10. The electronic cigarette of claim 9 wherein the main air flow through channel is arranged substantially normal to the plane of the pressure sensing surface.

11 . The electronic cigarette of any preceding claim further comprising an air inlet tube arranged between the air inlet in the housing and the pressure sensor housing wherein the air inlet tube is connected to the main airflow through channel of the pressure sensor housing such that together the air inlet tube and the main airflow through channel provide an air flow route from the air inlet to the vaporiser.

12. The electronic cigarette of claim 11 wherein the pressure channel opening is provided on a protruding portion of the pressure sensor housing, the protruding portion sleeved within or around the air inlet tube to provide a sealed connection between the air inlet tube and the main airflow through channel of the pressure sensor housing.

13. The electronic cigarette according to any preceding claim wherein the pressure sensor housing comprises one or more lead wire through holes running through the housing for connections between the electrical components of the device to pass through the pressure sensor housing, wherein the holes comprise a film sealing one side of the lead wire through holes to prevent air passing through the lead wire through holes.

14. The electronic cigarette according to any preceding claim further comprising an air channel plug positioned within the housing between the air inlet and the pressure sensor housing wherein the air channel plug comprises an air inlet channel and the air channel plug is arranged to provide a seal across the internal volume of the housing such that air entering the air inlet is restricted to passing through the air channel to the pressure sensor housing.

15. The electronic cigarette of claim 14 wherein the air channel plug extends from an inner surface of the housing at the air inlet to the pressure sensor housing and the air channel connects the air inlet with the main airflow channel of the pressure sensor housing.

16. The electronic cigarette of any preceding claim further comprising a PCB wherein the plane of the PCB is arranged substantially normal to the pressure sensing surface of the pressure sensor.