The present disclosure relates to a device for an aerosol provision system that comprises a drive assembly, aerosol provision systems including such a device, and a method of operating such a device.
Many aerosol provision systems, such as electronic systems including e-cigarettes and other electronic nicotine delivery systems that deliver nicotine by vaporizing or heating a suitable material, are formed from two main components or sections, which may be termed a device and an article. The device is a control or power section or component, and may include a power source such as a battery, and a controller or control unit, comprising electronics configured to operate the system, such as circuitry and/or software. The article may be considered as a cartridge or cartomizer section, and includes a storage area, such as a reservoir, for aerosolizable material, and often an aerosol generator or aerosol generating element such as a heater configured to generate vapor for aerosol formation from the aerosolizable material. The article may be intended to be disposable when the aerosolizable material is exhausted so that it is replaceable with a new article for use in conjunction with the device, where the device is intended to operate over the lifetime of many articles. In such a system, the article as a whole may be termed a consumable or consumable component. Alternatively, the article may include a smaller disposable component or consumable containing the aerosolizable material which can be replaced when exhausted. Particularly in the case of consumable articles, the consumable and the device are separate elements that couple together to form the system.
The reservoir may have a syringe-like configuration, operable to dispense the aerosolizable material by movement of a plunger that reduces the reservoir volume and forces material through an outlet. The plunger can be moved by the action of a pushing element, typically housed in the device and driven therefrom. The pushing element requires accurate control to enable correct dispensing of the aerosolizable material.
Arrangements for controlling the dispensing of aerosolizable material from a syringe-style reservoir are therefore of interest.
According to a first aspect of some embodiments described herein, there is provided a device component for an aerosol provision system, the device component comprising: a drive rod for pushing against a movable plunger in order to displace aerosol generating material through an outlet of a reservoir for storing aerosol generating material; a proximity detector configured to detect a spacing of the drive rod from the plunger; a drive assembly operable to advance the drive rod in a pushing direction, at a first speed to approach the plunger and at a second speed when against the plunger to move the plunger in order to displace aerosol generating material, the first speed being faster than the second speed; and a controller configured to operate the drive assembly to advance the drive rod at the first speed from a spacing of the drive rod from the plunger that exceeds a predetermined spacing, and to cease advancing the drive rod at the first speed in response to detection of a spacing that is substantially equal to or less than the predetermined spacing.
According to a second aspect of some embodiments described herein, there is provided an aerosol provision system comprising a device component according the first aspect, and a consumable component configured for connection to the device component and comprising a reservoir for storing aerosol generating material and a movable plunger for displacing aerosol generating material through an outlet of the reservoir when pushed by the drive rod of the device component.
According to a third aspect of some embodiments described herein, there is provided a method for dispensing aerosol generating material from a reservoir in an aerosol provision system; the method comprising: advancing a drive rod in a pushing direction at a first speed to approach a movable plunger for displacing aerosol generating material through an outlet of a reservoir for storing aerosol generating material, from a spacing of the drive rod from the plunger that exceeds a predetermined spacing of the drive rod from the plunger; monitoring the spacing of the drive rod from the plunger during the advancing at the first speed; ceasing the advancing at the first speed when the monitoring indicates that the spacing is substantially equal to or less than the predetermined spacing; and subsequently, when aerosol generating material is required to be displaced from the reservoir, advancing the drive rod against the plunger to push the plunger to displace aerosol generating material through the outlet, at a second speed which is slower than the first speed.
According to a fourth aspect of some embodiments described herein, there is provided a device component for an aerosol provision system, the device component comprising: a drive rod for pushing against a movable plunger in order to displace aerosol generating material through an outlet of a reservoir for storing aerosol generating material; a drive assembly operable to advance the drive rod in a pushing direction, at a first speed to approach the plunger and at a second speed when against the plunger to move the plunger in order to displace aerosol generating material, the first speed being faster than the second speed; and a controller configured to operate the drive assembly to advance the drive rod at the first speed from a spacing of the drive rod from the plunger that exceeds a predetermined spacing, and to cease advancing the drive rod at the first speed when the spacing of the drive rod from the plunger is substantially equal to the predetermined spacing; and operate the drive assembly to advance the drive rod at the second speed to move the plunger to displace aerosol generating material when aerosol generating material is required.
According to a fifth aspect of some embodiments described herein, there is provided a method for dispensing aerosol generating material from a reservoir in an aerosol provision system; the method comprising: advancing a drive rod in a pushing direction at a first speed to approach a movable plunger for displacing aerosol generating material through an outlet of a reservoir for storing aerosol generating material, from a spacing of the drive rod from the plunger that exceeds a predetermined spacing of the drive rod from the plunger; ceasing the advancing at the first speed when the spacing of the drive rod from the plunger is substantially equal to the predetermined spacing; and subsequently, when aerosol generating material is required to be displaced from the reservoir, advancing the drive rod against the plunger to push the plunger to displace aerosol generating material through the outlet, at a second speed which is slower than the first speed.
These and further aspects of the certain embodiments are set out in the appended independent and dependent claims. It will be appreciated that features of the dependent claims may be combined with each other and features of the independent claims in combinations other than those explicitly set out in the claims. Furthermore, the approach described herein is not restricted to specific embodiments such as set out below, but includes and contemplates any appropriate combinations of features presented herein. For example, an aerosol provision system, a device therefor, or a method of operating the device may be provided in accordance with approaches described herein which includes any one or more of the various features described below as appropriate.
Various embodiments of the disclosure will now be described in detail by way of example only with reference to the following drawings in which:
Aspects and features of certain examples and embodiments are discussed/described herein. Some aspects and features of certain examples and embodiments may be implemented conventionally and these are not discussed/described in detail in the interests of brevity. It will thus be appreciated that aspects and features of apparatus discussed herein which are not described in detail may be implemented in accordance with any conventional techniques for implementing such aspects and features.
As described above, the present disclosure relates to (but is not limited to) aerosol or vapor provision systems, also referred to as delivery systems or simply systems, such as e-cigarettes. Throughout the following description the terms “e-cigarette” and “electronic cigarette” may sometimes be used; however, it will be appreciated these terms may be used interchangeably with aerosol (vapor) provision or delivery system. In particular, the systems can be considered to be non-combustible aerosol provision systems, that release compounds from an aerosol-generating material (aerosolizable material) without combusting the aerosol-generating material, such as electronic cigarettes and hybrid systems. Such systems are intended to generate an inhalable aerosol by vaporization of an aerosol-generating material in the form of a liquid or gel which may or may not contain nicotine. Additionally, hybrid systems may comprise a liquid or gel material plus a solid substrate which is heated. The solid substrate may be for example tobacco or other non-tobacco products, which may or may not contain nicotine. The terms “aerosolizable material” and “aerosol-generating material” as used herein are intended to refer to materials which can form an aerosol, either through the application of heat or some other means. The term “aerosol” may be used interchangeably with “vapor”.
According to the present disclosure, a “non-combustible” aerosol provision system is one where a constituent aerosol-generating material in the aerosol provision system (or a component thereof) is not combusted or burned in order to facilitate delivery of at least one substance to a user. In some embodiments, the delivery system is a non-combustible aerosol provision system, such as a powered or electronic non-combustible aerosol provision system. In some embodiments, the non-combustible aerosol provision system is an electronic cigarette, also known as a vaping device or electronic nicotine delivery system (END), although it is noted that the presence of nicotine in the aerosol-generating material is not a requirement. In some embodiments, the non-combustible aerosol provision system is a hybrid system to generate aerosol using a combination of aerosol-generating materials, one or a plurality of which may be heated. Each of the aerosol-generating materials may be, for example, in the form of a solid, liquid or gel and may or may not contain nicotine. In some embodiments, the hybrid system comprises a liquid or gel aerosol-generating material and a solid aerosol-generating material. The solid aerosol-generating material may comprise, for example, tobacco or a non-tobacco product. Typically, the non-combustible aerosol provision system may comprise a non-combustible aerosol provision device and a consumable for use with the non-combustible aerosol provision device. In some embodiments, the disclosure relates to consumables comprising aerosol-generating material and configured to be used with non-combustible aerosol provision devices. These consumables are sometimes referred to as articles throughout the disclosure. In some embodiments, the non-combustible aerosol provision system, such as a non-combustible aerosol provision device thereof, may comprise a power source and a controller. The power source may, for example, be an electric power source or an exothermic power source. In some embodiments, the exothermic power source comprises a carbon substrate which may be energized so as to distribute power in the form of heat to an aerosol-generating material or to a heat transfer material in proximity to the exothermic power source. In some embodiments, the non-combustible aerosol provision system may comprise an area for receiving the consumable, an aerosol generator, an aerosol generation area, a housing, a mouthpiece, a filter and/or an aerosol-modifying agent. In some embodiments, a consumable for use with the non-combustible aerosol provision device may comprise aerosol-generating material, an aerosol-generating material storage area, an aerosol-generating material transfer component, an aerosol generator, an aerosol generation area, a housing, a wrapper, a filter, a mouthpiece, and/or an aerosol-modifying agent.
Aerosol-generating material (or aerosolizable material) is a material that is capable of generating aerosol, for example when heated, irradiated or energized in any other way. Aerosol-generating material may, for example, be in the form of a solid, liquid or gel which may or may not contain an active substance and/or flavorants. Embodiments of the disclosure are particularly concerned with aerosol-generating material in the form of a liquid or a gel. The aerosol-generating material may comprise one or more active substances and/or flavors, one or more aerosol-former materials, and optionally one or more other functional materials. The aerosol-former material may comprise one or more constituents capable of forming an aerosol. In some embodiments, the aerosol-former material may comprise one or more of glycerin, glycerol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,3-butylene glycol, erythritol, meso-erythritol, ethyl vanillate, ethyl laurate, a diethyl suberate, triethyl citrate, triacetin, a diacetin mixture, benzyl benzoate, benzyl phenyl acetate, tributyrin, lauryl acetate, lauric acid, myristic acid, and propylene carbonate. The one or more other functional materials may comprise one or more of pH regulators, coloring agents, preservatives, binders, fillers, stabilizers, and/or antioxidants.
Herein, a consumable is an article (component of an aerosol provision system) comprising or consisting of aerosol-generating material, part or all of which is intended to be consumed during use by a user. A consumable may comprise one or more other components, such as an aerosol-generating material storage area, an aerosol-generating material transfer component, an aerosol generation area, a housing, a wrapper, a mouthpiece, a filter and/or an aerosol-modifying agent. A consumable may also comprise an aerosol generator, such as a heater, that emits heat to cause the aerosol-generating material to generate aerosol in use. The heater may, for example, comprise combustible material, a material heatable by electrical conduction, or a susceptor.
The article 30 includes a reservoir 3 containing a source liquid or other aerosol-generating material comprising a formulation such as liquid or gel from which an aerosol is to be generated, for example containing nicotine. As an example, the source liquid may comprise around 1 to 3% nicotine and 50% glycerol, with the remainder comprising roughly equal measures of water and propylene glycol, and possibly also comprising other components, such as flavorings. Nicotine-free source liquid may also be used, such as to deliver flavoring. A solid substrate (not illustrated), such as a portion of tobacco or other flavor element through which vapor generated from the liquid is passed, may also be included. The reservoir 3 has the form of a storage tank, being a container or receptacle in which source liquid can be stored such that the liquid is free to move and flow within the confines of the tank. For a consumable article, the reservoir 3 may be sealed or otherwise made inaccessible after filling during manufacture so as to be disposable after the source liquid is consumed; otherwise, it may have an inlet port or other opening through which new source liquid can be added by the user. The article 30 also comprises an aerosol generating component or aerosol generator 4, for example an electrically powered heating element or heater located externally of the reservoir tank 3 for generating the aerosol by vaporization of the source liquid by heating. A liquid transfer or delivery arrangement (liquid transport element or more generally an aerosol-generating material transfer component) such as a wick or other porous element (not shown) may be provided to deliver source liquid from the reservoir 3 to the aerosol generator 4. A wick may have one or more parts located inside the reservoir 3, or otherwise be in fluid communication with the liquid in the reservoir 3, so as to be able to absorb source liquid and transfer it by wicking or capillary action to other parts of the wick that are adjacent to or in contact with the aerosol generator 4. In other arrangements, liquid may be dispensed from the reservoir 3 directly onto, or into the vicinity of, the aerosol generator 4. The liquid delivered to the aerosol generator is then vaporized by action of the aerosol generator, for example by heating if the aerosol generator is a heater or heating element, to be replaced by new source liquid from the reservoir 3 for transfer to the heater 4.
A heater and wick (or other aerosol-generating material transfer component) combination is sometimes referred to as an atomizer or atomizer assembly, and the reservoir with its source liquid plus the atomizer may be collectively referred to as an aerosol source. Various designs are possible, in which the parts may be differently arranged compared with the highly schematic representation of
Returning to
The device 20 includes a cell or battery 5 (referred to herein after as a battery, and which may or may not be re-chargeable) to provide electrical power for electrical components of the system 10, in particular to operate the aerosol generator. Additionally, there is a controller 8 such as a printed circuit board and/or other electronics or circuitry for generally controlling the system 10. The controller 8 may include a processor programmed with software, which may be modifiable by a user of the system 10. The control electronics/circuitry 8 operates the aerosol generator 4 using power from the battery 5 when vapor is required. At this time, the user inhales on the system 10 via the mouthpiece 6, and air A enters through one or more air inlets 9 in the wall of the device 20 (air inlets may alternatively or additionally be located in the article 30). When the aerosol generator 4 is operated, it vaporizes source liquid delivered from the reservoir 3 to generate the aerosol by entrainment of the vapor into the air flowing through the system 10, and this is then inhaled by the user through the opening 7 in the mouthpiece 6. The aerosol is carried from the aerosol generator 4 to the mouthpiece 6 along one or more air channels (not shown) that connect the air inlets 9 to the aerosol generator 4 to the air outlet 7 when a user inhales on the mouthpiece 6.
The device 20 and the article 30 are separate connectable parts detachable from one another by separation in a direction parallel to the longitudinal axis, as indicated by the arrow C in
Some designs of aerosol provision system have a reservoir arrangement in the consumable component from which non-solid aerosol-generating material is dispensed by being forced out of an outlet in the reservoir wall. This is achieved by configuring the reservoir to have a movable wall that can slide under the application of a pushing force in an inwards direction to reduce the internal volume of the reservoir where the material is stored. The reduction in volume increases the pressure on the material in the reservoir, and an amount of material leaves the reservoir via the outlet in order to reduce the pressure to an equilibrium level. The pushing force is applied by a push applicator that acts on the movable wall on an exterior side, opposite to an interior side that faces into the internal volume of the reservoir. The push applicator, which may take a variety of forms, is accommodated in the device component, and operable to provide the pushing force to the movable wall when the device component and the consumable component are coupled, engaged or connected together to form the aerosol provision system.
A reservoir arrangement of this type can provide some benefits as compared to a fixed volume reservoir which develops a volume of air (headspace) inside as the aerosol generating material is consumed. Leakage can be reduced, since a headspace can change volume due to changes in ambient pressure or temperature, thereby pushing material from the reservoir at unwanted times. Requirements for viscosity of the aerosol generating material are relaxed; the material does not need to flow, merely be able to be displaced. The system is made independent of orientation since there is no reliance on gravity for the flow of liquid out of the reservoir. Rather, the material is pushed out of the reservoir on demand, by operation of the push applicator at appropriate times, so the system can be used upside down for an extended period, such as if the user is reclining. Similarly, the absence of any gravitational feed also increases the options for the relative orientation of the reservoir and the aerosol generator.
The consumable 30 has an outer wall 11, which might have a cylindrical transverse cross-section, which defines within it a space of which part acts as a reservoir 3 for storing aerosol generating material in an internal volume. This volume is also bounded by a fixed wall 13 which extends transversely across the space inside the outer wall 11 at a position towards the mouthpiece end 6 of the consumable 30, and by a movable wall 12 which also extends transversely across the space inside the outer wall 11, at a position proximate to the connecting end of the consumable. The space between the fixed wall 13 and the movable wall 12 is the reservoir 3. The fixed wall 13 has an outlet 15 therein through which aerosol generating material stored in the reservoir 3 can be dispensed, indicated by the arrow L. The dispensed material is delivered to an aerosol generator 4, located in an aerosol generating space or cavity between the fixed wall 13 and the mouthpiece 6, that acts on the material to generate a vapor in any known manner, such as by heating. The aerosol-generating material L can be dispensed directly onto the aerosol generator 4, or into the vicinity of the aerosol generator in a region into which the action of the aerosol generator 4 extends, or onto or into some form of aerosol generating material transport element such as a wick or porous element or capillary tube that carries material from the outlet 15 to or near the aerosol generator 4.
The movable wall 12 is not fixed and is configured to be able to move or slide over the inner surface of the outer wall 11 in an inwards direction, that is, towards the fixed wall 13. This movement reduces the internal volume of the reservoir 3, increases the pressure in the aerosol-generating material, and causes a portion of the material to be displaced through the outlet 15. A suitable sealing arrangement is provided around the perimeter of the movable wall 12 in order to reduce or prevent leakage of the aerosol-generating material through the junction between the moveable wall 12 and the outer wall 11, thereby providing an effectively water-tight internal storage volume except for the outlet 15. A rubber or silicone gasket might be suitable, for example, or the moveable wall 12 itself may be formed from a flexible resilient material of this type. This inward movement of the moveable wall, indicated by the arrow W, is effected by a pushing force applied to the outer surface of the moveable wall 12, that is, the surface that does not face towards the reservoir interior. The pushing force acts substantially perpendicularly to the plane of the movable wall (which in this example is flat, but need not be), along the desired inward direction of movement W.
Accordingly, the delivery of aerosol-generating material from the reservoir 3 can be considered analogously to the ejection of liquid from a syringe, where the outer wall 11 of the consumable 30 corresponds to the barrel of the syringe, and the movable wall 12 corresponds to the plunger of the syringe. In the following, the term “plunger” may be used to refer to the movable wall 12.
Note that a reservoir with a reducible volume effected by a movable wall need not be configured as shown in
The device 20 comprises a battery 5 and a controller or control electronics 8 as before. Additionally, the device comprises a push applicator 14, being a device, apparatus, means or other arrangement operable to provide and apply the required pushing force P to the movable wall 12, when the device 20 is engaged with the consumable 30. The push applicator 14 can be operable under the control of the controller 8 to provide an amount of pushing force P necessary to dispense a required volume or portion of material from the reservoir at an appropriate time. Typically this will be when a user requires aerosol provision, in other words, wishes to inhale or “puff” on the system. At the same time or very shortly thereafter, the aerosol generator 4 is also activated, by the controller 8, in order to vaporize the dispensed portion of material. The push applicator 14 and the aerosol generator 4 can be activated by the controller 8 in response to user actuation of an input control element on the exterior of the system, such as a button or switch (not shown), or in response to a flow of air through the system detected by an air flow sensor or air pressure sensor (puff detector, also not shown) when the user begins to inhale via the mouthpiece 6. The push applicator 14 may be activated for a pre-set amount of time configured to dispense a predetermined volume of material, such as an amount generally corresponding to the amount of vapor consumed in an average puff, or it may be activated for the duration of the puff, in other words until the end of the puff as detected by the cessation of user activation of the input control element or the cessation of air flow, or for some other time, or to provide a predetermined amount of force. The push applicator 14 may take a variety of forms.
In use, the drive rod 41 has an initial retracted position in which it is housed wholly or largely within the device 20. After the device 20 is connected to the consumable 30, the drive assembly 40 acts to advance the rod 41 in the pushing direction to make contact with the plunger 12, or to be in close proximity thereto. The rod 41 is therefore located in a position for it to pushing against the plunger 12 in order to enable rapid dispensing from the reservoir when aerosol generating material is needed. This initial advancement may be made in response to detection of the consumable 30 being connected to the device 20 by a detector (not shown) when sends a detection signal to the controller 8. Then, each time aerosol is required, the controller 8 activates the drive assembly to operate the rod 41 such that it advances an appropriate distance, thereby applying the pushing force P against the plunger 12 in order to move it inwardly W. After each puff, the rod 41 may maintain its current position against or in contact with the plunger 12, ready for further advancement when the next puff is demanded. Once the reservoir has been emptied, which might be detected by detection of a maximum extension or advancement of the rod 41 from the driver unit 40 for example, the drive assembly 40 can operate in reverse to retract the rod 41 to its initial position within the device 20. This will enable the consumable 30 to be disconnected from the device 20 for replacement.
In some systems, it may further be possible to separate the consumable from the device before it is completely empty, and reinstall it at a later time for consumption of the remaining aerosol generating material. This allows the user to switch between different types of aerosol generating material, such as changing flavor, without having to wait until the reservoir is empty or throwing away an only partially-consumed consumable. Also, it may be that consumables are provided with different volumes of aerosol generating material therein, such as smaller sample quantities of material to allow the user to test different types. In these various circumstances, the position of the plunger is not fixed across all consumables that might possibly be connected to the device. Consequently, it is not feasible, when a consumable is connected to the device, for the controller merely to cause the drive rod to be advanced by a set distance in order for it to be located for pushing against the plunger.
Instead, the drive rod should be advanced until it is properly located for pushing against the plunger, regardless of the plunger position and hence the spacing between the end of the drive rod and the plunger when the consumable and the device are coupled together. The amount of initial advancement required prior to dispensing is therefore variable. Subsequent incremental advancement of the drive rod for pushing the plunger and dispensing aerosol substrate material may be a fixed distance each time, corresponding to a fixed dose of material, and is typically carried out at a relatively low speed, since the distances to be covered are small, and in order to achieve smooth dispensing and avoid jerky movement of the plunger.
If this same speed is used to move the drive rod during the initial advancement, it may take an unacceptably long time for the system to be placed into an operational state, ready for aerosol generation. This is particularly the case for a near-empty reservoir, when the spacing between the drive rod and the plunger is large. Accordingly, it is proposed that the drive assembly be configured to advance the drive rod at more than one speed, under direction from the controller. A first speed is enabled, for moving the drive rod from its initial retracted position towards the plunger and into position for pushing against the plunger. A second speed is also enabled, for moving the drive rod when it is contact with the plunger in order to push the plunger inwards and dispense material from the reservoir. The first speed is faster (higher, greater, larger) than the second speed. Conversely, the second speed is slower (lower, less, smaller) than the first speed. The provision of multiple drive speeds enables the system can be rendered operable more rapidly when the consumable is connected to the device.
However, recall that the position of the plunger is variable, and unknown to the controller. It is undesirable to continue movement of the drive rod at the first speed once it is in contact with the plunger, since this will reduce the reservoir volume very quickly and cause unwanted quantities of aerosol generating material to be dispensed. Accordingly, it is also proposed that the proximity of the drive rod to the plunger be monitored, measured or detected while the drive rod is approaching the plunger at the first speed, and when the proximity (spacing between the drive rod and the plunger) is detected to have decreased to a predetermined spacing, the drive assembly ceases operation at the first speed. Upon detection of the predetermined spacing, the drive assembly can switch to the second speed, or switch to another speed which is slower than the first speed, or halt the advancement of the drive rod. The predetermined spacing may be a positive value, at which the drive rod is separated from the plunger, or the predetermined spacing may be zero, at which the drive rod is in contact with the plunger. In this way, the drive rod can be moved at an appropriate speed according to its separation from or contact with the plunger, for any plunger position, and avoiding unwanted rapid pushing of the plunger.
We can define a range of variables to describe the different combinations of positions and speeds. These are indicated on and described with respect to the following highly schematic diagrams.
Referring back to
From these examples it will be appreciated that the position of the drive rod when it is deemed to be “located for pushing against the plunger” is defined so as to include the alternatives of being located in already in contact with the plunger so that movement of the drive rod immediately pushes the plunger, and being located slightly spaced apart from the plunger so that an initial movement is needed to contact the plunger before pushing begins. The latter arrangement may include a small retraction of the drive rod after each pushing action in order to reinstate the slight spacing; this can relieve pressure inside the reservoir and reduce the risk of accidental ejection of liquid that might arise from physical shocks or thermal expansion.
The third speed S3 used to move the drive rod 41 from the predetermined spacing into its final position Y ready for pushing can be slower than the first speed S1. In some examples it may be substantially the same as the second speed S2. In other examples it may be faster than S2. This contributes to the rapid positioning of the drive rod to place the system into an operable state while avoiding the use of the fastest drive speed when the drive rod is very close to the plunger. This can reduce the risk of accidental high speed impact of the drive rod with the plunger in the event of errors in the proximity detection. Alternatively, the third speed S3 may be slower than S2. This can allow more precise positioning of the drive rod into the pushing location Y. In summary, S1>S2 and S1>S3, where S2=S3 or S2>S3 or S2<S3.
In another example, the distance d3 can be selected to be zero. In other words, the drive rod is placed in contact with the plunger in order to be located ready for pushing, as in the
In examples in which the location for pushing, drive rod position Y, is spaced apart from the plunger (d3>0), the initial part of the pushing action in which the drive rod is advanced over the distance d3 to reach the plunger may be effected at the second speed S2, as noted above, or at the third speed S3, or at some other speed different from both the second speed S2 and the third speed S3 and also less than the first speed S1.
From the foregoing description it will be understood that in order to achieve the proposed multi- or dual-speed driving of the drive rod by the drive assembly, it is appropriate to detect the proximity of the drive rod to the plunger. In this context, the proximity is the spacing or distance between the drive rod and the plunger, or the separation of the drive rod from the plunger. If the proximity is detected while the drive rod is approaching the plunger at the first speed, it can be established when the drive rod reaches the predetermined spacing from the plunger by comparison of the detected proximity with the value of the predetermined spacing. When the predetermined spacing is reached, the advancement of the drive rod at the first speed is stopped.
This can be achieved by the use of a proximity detecting arrangement or proximity detector which monitors the spacing while the drive rod is being driven at the first speed by the drive assembly under control of the controller. The proximity detector can continuously or periodically output values of the measured proximity which are provided to the controller. The controller repeatedly compares the most recent value of the measured proximity with a stored value of the predetermined spacing. When the comparison determines that the measured proximity is substantially equal to the predetermined spacing, the controller stops operation of the drive assembly to move the drive rod at the first speed. This can be followed by the controller sending control signals to the drive assembly for any of various immediate or subsequent movements of the drive rod at the second speed, the third speed or another slower speed according to the various examples set out above.
Alternatively, the comparison may be carried out to look for a measured proximity that is slightly larger than the predetermined spacing, so that the controller instructs cessation of movement at the first speed before the predetermined spacing is reached. This can allow for processing time and the time required to bring the drive rod to a halt (inertial effects, for example), so that when the movement ceases, the drive rod has arrived at the predetermined spacing. This may be useful in examples where the predetermined spacing is substantially zero (
To implement this, the device additionally comprises a proximity detector, configured to detect the spacing or distance between the drive rod and the plunger. This can be the distance between the end surface of the drive rod and the exterior surface of the plunger, as depicted in the
The capacitor plates may be differently configured if desired. For example, the plunger 12 may itself be made from a suitable conductive or dielectric material. Alternatively a portion of a suitable material might be embedded within the plunger, or provided on the interior surface of the plunger, where a coating of a suitable material might also be used. These arrangements can be used if the plunger is made from a non-conductive material unsuited for use as a capacitor plate, and may be useful in protecting the second capacitor plate 52 from damage when the drive rod 41 impacts the plunger 12. For similar reasons, the first capacitor plate 50 might be embedded behind the end surface of the drive rod 41, or provided with a non-conductive protective coating.
A time of flight proximity detector may also be implemented by placing the sensor 56 on the plunger and reflecting the pulses off the advancing drive rod, or by placing one of the transmitter or the receiver on the drive rod and the other of the transmitter or the receiver on the plunger (so that the pulse travels across the spacing for direct detection, rather than undergoing reflection and a round trip). However, these arrangements may be more complex to implement since electrical connectivity to the parts in the consumable is needed.
Proximity sensors such as a capacitive sensor or a time-of-flight sensor can be used to continuously monitor the spacing between the drive rod and the plunger, and are able to provide measurements that allow a positive predetermined spacing to be monitored, in other words, a predetermined spacing in which the drive rod is separated from the plunger. A predetermined spacing of zero, where the drive rod is in contact with the plunger, can also be detected, at least by looking for a sudden change in the measured response that results from contact being made. For example, for time of flight detection, the return pulse will become undetectable when the drive rod abuts the plunger, so the signal detected by the time of flight sensor will suddenly drop to zero. A similar sudden change in capacitance will occur if the two capacitor plates in a capacitive sensor make contact, since the capacitive ability is lost and the capacitance will drop to zero. Alternatively, if at least one of plates is located away from the abutting surfaces of the drive rod and the plunger (for example if the aerosol generating material in the reservoir is used as the second capacitor plate), a detectable capacitance will be maintained even when the drive rod impacts the plunger.
Further alternative arrangements are able to detect a zero predetermined spacing, that is, when contact is made by the drive rod onto the plunger, by implementing proximity detection based on the operation of an electric motor comprised in the drive assembly.
When the drive rod makes contact with the plunger, the load on the motor will increase. More force is required to make the drive rod continue to advance, since it is now pushing against the plunger. The motor now has to work to move both the drive rod and the plunger. The increased load will cause the motor to drawn more current from the device's battery. Accordingly, when impact occurs, there is a surge in current drawn by the motor. The detector 62 can therefore be a current detector that monitors the current drawn by the motor. A current surge will be detected by the detector as a sudden spike or increase in current, and this condition will be communicated to the controller 8 to cause the first speed driving of the drive rod to be switched off. Other operational parameters of the motor undergo change with the increased load, so can be similarly monitored to detect when contact is made between the drive rod and the plunger. For example, the rotational speed of the motor will change for a fixed power. Other parameters may be apparent to the skilled person and may alternatively be monitored as well.
The drive rod may be provided with a compressible member on its end, such as a spring or a foam portion. This will compress when contact is made with the plunger and cause a more gradual change in the load on the motor. This can be still be detected, however and the drive rod brought to a halt (or switched to a slower speed) while compression is still ongoing so that no movement is imparted to the plunger.
More generally, the concept of dual-speed driving of the drive rod can be implemented without the proximity detection. For example if the consumable is configured such that it can only be coupled to a device when the reservoir is full, and the plunger position is therefore fixed between consumables, the distance over which the drive rod needs be moved to take it from its retracted position to the location for pushing against the plunger is always constant, for every consumable. Accordingly, the drive rod can be advanced at the first speed in order to cover the necessary distance. Subsequently, when aerosol generation is desired and it is necessary to dispense aerosol generating material from the reservoir, the drive rod is advanced at the second, slower, speed to push the plunger forward and displace material through the reservoir outlet. Operation of the motor in order to carry the drive rod over the required distance at the first speed can be for a number of revolutions of the motor known to correspond to that distance for example. An encoder could also be used to track the distance. Another alternative is to operate the motor at the first speed for a fixed time corresponding to the distance, but this approach may be less robust since factors such as differences in voltage available from the battery or varying friction would cause variations in the distance for which the drive rod would be moved in the fixed time.
Consequently, the example method of
In all examples and embodiments, the various speeds, in particular the first speed and the second speed, can be selected having regard to the overall design of the aerosol provision system in order to achieve the desired reduced speed for dispensing the aerosol generating material together with a minimal delay in engaging the drive rod and the plunger after the device and the consumable are connected together. The slower second speed can be a function of an output power for the system selected by the user since this is related to the mass of aerosol generating material that needs to be dispensed for vaporization. The absolute value for the second speed will depend on aspect ratio of the consumable and the cross-sectional area of the reservoir since this determines the amount of aerosol generating material dispensed per given distance travelled by the plunger.
Examples above have been described in terms of the controller positively controlling the motor to operate at the various different speeds when it is known that the drive rod is in any of the corresponding positions. However, this positive control may not be necessary, and the required slower second speed may arise by default as a consequence of motor operation. If the motor is supplied with an appropriate constant power level, it will operate to move the drive rod at a corresponding first speed while the motor is loaded only with the drive rod. When the drive rod contacts the plunger, the load on the motor increases as it works to push the plunger and displace the aerosol generating material out of the reservoir, and if the power is maintained at the same level, the speed will decrease, thereby producing the slower second speed by default.
The various embodiments described herein are presented only to assist in understanding and teaching the claimed features. These embodiments are provided as a representative sample of embodiments only, and are not exhaustive and/or exclusive. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects described herein are not to be considered limitations on the scope of the disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilized and modifications may be made without departing from the scope of the claims. Various embodiments of the disclosure may suitably comprise, consist of, or consist essentially of, appropriate combinations of the disclosed elements, components, features, parts, steps, means, etc., other than those specifically described herein. In addition, this disclosure may include other inventions not presently claimed, but which may be claimed in future.
Number | Date | Country | Kind |
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2014416.8 | Sep 2020 | GB | national |
The present application is a National Phase entry of PCT Application No. PCT/GB2021/052251, filed Aug. 31, 2021, which claims priority from GB Application No. 2014416.8, filed Sep. 14, 2020, each of which hereby fully incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/GB2021/052251 | 8/31/2021 | WO |