DEVICE WITH DRIVE ASSEMBLY FOR AN AEROSOL DISPENSING SYSTEM

Abstract

A device component for an aerosol delivery system comprises: a drive rod for pushing against a movable plunger to displace the aerosol-generating material through an outlet of a reservoir for storing the aerosol-generating material; a proximity sensor configured to detect a separation of the drive rod from the plunger; a drive assembly operable for advancing 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 the 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 first speed from a gap between the drive rod and the plunger that exceeds a predetermined gap, and to cease advancing the drive rod at first speed in response to the detection of a gap that is substantially equal to or less than the predetermined gap.

Description

DEVICE WITH DRIVE ASSEMBLY FOR AN AEROSOL DISPENSING SYSTEM TECHNICAL FIELD This description relates to a device for an aerosol delivery system comprising a drive assembly, aerosol delivery systems including said device, and a method for operating said device. BACKGROUND Many aerosol delivery systems, such as electronic systems including e-cigarettes and other electronic nicotine delivery systems that administer nicotine by vaporizing or heating a suitable material, consist of two main components or sections, which may be referred to as the device and the 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 electronic components configured to operate the system, such as circuitry and / or software. The article may be considered 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 item may be intended to be disposable when the aerosolized material is depleted, so that it can be replaced with a new item for use with the device, where the device is intended to function over the lifetime of many items. In such a system, the item as a whole may be referred to as a consumable or consumable component. Alternatively, the item may include a smaller disposable component or consumable that contains the aerosolized material, which can be replaced when depleted. Particularly in the case of consumable items, the consumable and the device are separate elements that are assembled to form the system. The reservoir may have a syringe-like configuration, operable to dispense the aerosolized material by the movement of a plunger that reduces the reservoir's volume and forces the material through an outlet. The plunger may be moved by the action of a pusher, typically housed within and operated by the device. The pusher requires precise control to ensure accurate distribution of the aerosolized material. The arrangements for controlling the distribution of aerosolizable material from a syringe-style reservoir are therefore of interest. BRIEF DESCRIPTION According to a first aspect of some embodiments described in this document, a device component for an aerosol delivery system is provided, the device component comprising: a drive rod for pushing against a movable plunger to displace aerosol-generating material through an outlet of a reservoir for storing aerosol-generating material; a proximity detector configured to detect a separation of the drive rod from the plunger; a drive assembly operable for advancing 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 the 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 first speed from a separation between the drive rod and the plunger that exceeds a predetermined separation. According to a second aspect of some embodiments described in this document, an aerosol delivery system is provided comprising a device component according to the first aspect, and a consumable component configured to connect to the device component and comprising a reservoir for storing aerosol-generating material and a movable plunger for displacing the 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, a method is provided for dispensing aerosol-generating material from a reservoir in an aerosol delivery system; the method comprises: advancing a drive rod in a thrust 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 drive rod-plunger clearance that exceeds a predetermined drive rod-plunger clearance; monitoring the drive rod-plunger clearance during advancement at the first speed; and ceasing advancement at the first speed when the monitoring indicates that the clearance is substantially equal to or less than the predetermined clearance.and subsequently, when it is required that the aerosol generating material be displaced from the reservoir, advance the drive rod against the plunger to push the plunger and displace the aerosol generating material through the outlet, at a second speed that is slower than the first speed. According to a fourth aspect of some embodiments described in this document, a device component for an aerosol delivery system is provided, the device component comprising: a drive rod for pushing against a movable plunger to displace aerosol-generating material through an outlet of a reservoir for storing aerosol-generating material; an operable drive assembly for advancing 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 the 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 first speed from a gap between the drive rod and the plunger that exceeds a predetermined gap, and to stop advancing the drive rod at first speed when the gap between the drive rod and the plunger is substantially equal to the predetermined gap; and to operate the drive assembly to advance the drive rod at second speed to move the plunger to displace the aerosol-generating material when aerosol-generating material is required. ινίΛ / a In accordance with a fifth aspect of some embodiments described herein, a method is provided for dispensing aerosol-generating material from a reservoir in an aerosol delivery system; the method comprises: advancing a drive rod in a thrust 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 separation of the drive rod from the plunger that exceeds a predetermined separation of the drive rod from the plunger; ceasing the advance at the first speed when the separation between the drive rod and the plunger is substantially equal to the predetermined separation;and subsequently, when it is required that the aerosol generating material be displaced from the reservoir, advance the drive rod against the plunger to push the plunger to displace the aerosol generating material through the outlet, at a second speed that is slower than the first speed. These and other aspects of certain embodiments are set forth in the appended independent and dependent claims. It will be appreciated that the features of the dependent claims can be combined with each other and the features of the independent claims in combinations other than those explicitly stated in the claims. Furthermore, the approach described herein is not limited to specific embodiments such as those set forth below, but includes and contemplates any appropriate combination of features presented herein. For example, an aerosol delivery system, a device for the same, or a method for operating the device may be provided in accordance with the approaches described herein that include one or more of the various features described below, as appropriate. BRIEF DESCRIPTION OF THE DRAWINGS Several embodiments of the invention will now be described in detail by way of example only with reference to the following drawings, in which: Figure 1 shows a simplified schematic cross-sectional view of an example aerosol delivery system to illustrate the typical components of such a system; Figure 2 shows a simplified schematic cross-sectional view of an example of an aerosol delivery system having a consumable with a reducible volume reservoir, to which examples from the description can be applied; Figure 3 shows a simplified side view of an example of a push applicator operable for moving a plunger in a reducible volume reservoir such as that of the consumable in the example system of Figure 2; Figures 4A-4F show simplified schematic representations of a push applicator drive rod and plunger in various positions to illustrate parameters of interest in example techniques for actuating the drive rod according to the present disclosure; Figure 5 shows a simplified schematic representation of a first example of a capacitive sensor for detecting proximity according to an example in the present description; Figure 6 shows a simplified schematic representation of a second example of ML / a capacitive sensor for detecting proximity according to an example in this disclosure; Figure 7 shows a simplified schematic representation of an example of a time-of-flight sensor for detecting proximity according to an example in this disclosure; Figure 8 shows a simplified schematic representation of an example of an arrangement for controlling motor operation in order to detect proximity, as per an example in this disclosure; and Figure 9 shows a flowchart of steps in a method for actuating a push applicator according to an example in the present description. DETAILED DESCRIPTION The aspects and characteristics of certain examples and modalities are analyzed / described in this document. Some aspects and characteristics of certain examples and modalities can be implemented conventionally and are not discussed / described in detail for the sake of brevity. Therefore, it will be appreciated that the aspects and characteristics of the apparatus discussed here that are not described in detail can be implemented according to any conventional technique for implementing such aspects and characteristics. As described above, this description refers to (but is not limited to) aerosol or vapor delivery systems, also called delivery systems or simply systems, such as electronic cigarettes. Throughout the following description, the terms “e-cigarette” and “electronic cigarette” may be used interchangeably; however, it will be appreciated that these terms can be used interchangeably with aerosol (vapor) delivery system. In particular, systems may be considered non-combustible aerosol delivery systems, which release compounds from an aerosol-generating material (aerosolizable material) without burning the aerosol-generating material, such as electronic cigarettes and hybrid systems. Such systems are intended to generate an inhalable aerosol by vaporizing an aerosol-generating material in the form of a liquid or gel that may or may not contain nicotine.Furthermore, hybrid systems may comprise a liquid or gel material plus a heated solid substrate. 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, refer to materials that can form an aerosol, either through the application of heat or some other means. The term “aerosol” may be used interchangeably with “vapor.”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, refer to materials that can form an aerosol, either through the application of heat or some other means. The term “aerosol” may be used interchangeably with “vapor.” IVIA / 1 / According to this disclosure, a “non-combustible” aerosol delivery system is one in which a constituent aerosol-generating material in the aerosol delivery system (or a component thereof) does not burn or combust to facilitate the delivery of at least one substance to a user. In some embodiments, the delivery system is a non-combustible aerosol delivery system, such as a motorized or electronic non-combustible aerosol delivery system. In some embodiments, the non-combustible aerosol delivery 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 delivery system is a hybrid system for generating aerosol using a combination of aerosol-generating materials, one or more of which may be heated. Each of the aerosol-generating materials may be, for example, in solid, liquid, or gel form 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 delivery system may comprise a non-combustible aerosol delivery device and a consumable for use with the non-combustible aerosol delivery device.In some embodiments, the disclosure refers to consumables comprising aerosol-generating material and configured for use with non-combustible aerosol delivery devices. These consumables are sometimes referred to as articles throughout the disclosure. In some embodiments, the non-combustible aerosol delivery system, such as a non-combustible aerosol delivery device therefor, may comprise a power source and a controller. The power source may be, for example, an electrical power source or an exothermic power source. In some embodiments, the exothermic power source comprises a carbon substrate that can be activated to distribute energy in the form of heat to an aerosol-generating material or a heat transfer material in the vicinity of the exothermic power source.In some embodiments, the non-combustible aerosol delivery system may comprise a consumable receiving area, an aerosol generator, an aerosol generation area, a housing, a nozzle, a filter, and / or an aerosol modifying agent. In some embodiments, a consumable for use with the non-combustible aerosol delivery 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 casing, a filter, a nozzle, and / or an aerosol modifying agent. An aerosol-generating material (or aerosolizable material) is a material capable of generating aerosols, for example, when heated, irradiated, or otherwise energized. The 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 flavorings. The description refers specifically to the aerosol-generating material in liquid or gel form. The aerosol-generating material may comprise one or more active substances and / or flavorings, one or more aerosol-forming materials, and optionally, one or more functional materials. The aerosol-forming material may comprise one or more constituents capable of forming an aerosol.In some embodiments, the aerosol-forming material may comprise one or more of glycerin, glycerol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,3-butylene glycol, erythritol, mesoerythritol, ethyl vanillate, ethyl laurate, diethyl suberate, triethyl citrate, triacetin, a mixture of diacetin, benzyl benzoate, benzylphenyl acetate, tributyrin, lauryl acetate, lauric acid, myristic acid, and propylene carbonate. One or more of the other functional materials may comprise one or more pH regulators, colorants, preservatives, binders, fillers, stabilizers, and / or antioxidants. In this document, a consumable is an item (a component of an aerosol delivery system) comprising or consisting of aerosol-generating material, in whole or in part, intended to be consumed during use by a user. A consumable may comprise one or more components, such as an aerosol-generating material storage area, an aerosol-generating material transfer component, an aerosol-generating area, a housing, a wrapper, a nozzle, a filter, and / or an aerosol-modifying agent. A consumable may also comprise an aerosol generator, such as a heater, which emits heat to cause the aerosol-generating material to produce aerosol during use. The heater may comprise, for example, combustible material, an electrically conductive material, or a susceptor. Figure 1 is a highly schematic (not to scale) diagram of a generic example of an aerosol delivery system (10), such as an electronic cigarette, presented to show the relationship between various parts of a typical system and to explain the general operating principles. Note that this disclosure is not limited to a system configured in this way, and the features may be modified according to the various alternatives and definitions described herein and / or evident to those skilled in the art.The electronic cigarette (10) has a generally elongated shape in this example, extending along a longitudinal axis indicated by a dashed line, and comprises two main components, namely, a device (20) (component, section or power control unit) and an article or consumable (30) (cartridge assembly or section, sometimes referred to as a cartomizer or clearomizer) that carries aerosol-generating material and operates as an aerosol-generating component. Article (30) includes a reservoir (3) containing a liquid source or other aerosol-generating material comprising a formulation such as a liquid or gel from which an aerosol, for example, containing nicotine, is to be generated. For example, the source liquid may comprise approximately 1 to 3% nicotine and 50% glycerol, with the remainder comprising approximately equal amounts of water and propylene glycol, and possibly also comprising other components, such as flavorings. A nicotine-free liquid source may also be used, such as to provide flavor. A solid (unpolished) substrate, such as a portion of tobacco or other flavoring element, through which the vapor generated by the liquid passes, may also be included. The reservoir (3) is in the form of a storage tank, being a container or receptacle in which source liquid can be stored so that the liquid moves freely and flows within the limits of the tank.For a consumable article, the reservoir (3) may be sealed or otherwise rendered inaccessible after filling during manufacturing so that it is disposable after the source liquid is consumed; otherwise, it may have an inlet port or other opening through which the user can add a new source of liquid. The article (30) also comprises an aerosol generating component or aerosol generator (4), for example, an electrically driven heating element or heater located outside the reservoir (3) for generating the aerosol by vaporizing the source liquid through heating. A liquid transfer or delivery device (liquid carrying element or, more generally, an aerosol generating material transfer component) such as a wick or other porous element (not shown) may be provided to supply source liquid from the reservoir (3) to the aerosol generator (4).A wick may have one or more parts located within the reservoir (3), or be in fluid communication with the liquid in the reservoir (3), so that it can absorb the source liquid and transfer it by capillary action or wick to other parts of the reservoir that are adjacent to or in contact with the aerosol generator (4). In other arrangements, the liquid may be dispensed from the reservoir (3) directly onto or near the aerosol generator (4). The liquid delivered to the aerosol generator is then vaporized by the action of the aerosol generator, for example, by heating if the aerosol generator is a heater or heating element, to be replaced by fresh source liquid from the reservoir (3) for transfer to the heater (4). A combination of heater and wick (or other aerosol-generating material transfer component) is sometimes called an atomizer or atomizer assembly, and the reservoir with its liquid source plus the atomizer may be collectively referred to as the aerosol source. Various designs are possible, in which the parts may be arranged differently compared to the highly schematic representation in Figure 1. For example, a material transfer component may be porous and be a completely separate element from the heater, or the heater itself may be configured to be porous and capable of performing at least part of the wick function directly (a metal mesh, for example). In an electrical or electronic device, the aerosol generator may be an electrical heating element that operates by ohmic / resistive (Joule) heating or by inductive heating.In general, therefore, an atomizer can be considered as one or more elements that implement the functionality of an aerosol generator or a vaporization element capable of generating vapor from the supplied source liquid, and a liquid delivery or transport element or arrangement capable of delivering or transporting liquid from a liquid reservoir or storage facility similar to the aerosol generator. An atomizer is usually housed in an item (30) of an aerosol delivery system, as in Figure 1, but in some examples, at least the aerosol generator may be housed in the device (20). As mentioned, in some designs the liquid can be dispensed from a reservoir directly into an aerosol generator without the need for a separate absorption or capillary element.The disclosure requirements apply to all such configurations that are consistent with the examples and description herein, and include a liquid conveying or delivery element or arrangement capable of delivering or conveying liquid from a liquid reservoir or storage facility similar to the aerosol generator. An atomizer is typically housed in an article (30) of an aerosol delivery system, as in Figure 1, but in some examples, at least the aerosol generator may be housed in the device (20). As mentioned, in some designs, the liquid may be dispensed from a reservoir directly into an aerosol generator without the need for a separate absorption element or capillary. The disclosure requirements apply to all such configurations that are consistent with the examples and description herein. Returning to Figure 1, the article (30) also includes a nozzle or nozzle portion (6) having an opening or air outlet (7) through which a user can inhale the aerosol generated by the aerosol generator (4). The device (20) includes a cell or battery (5) (hereafter referred to as the battery, which may or may not be rechargeable) to provide electrical power to the electrical components of the system (10), in particular to operate the aerosol generator. In addition, there is a controller (8), such as a printed circuit board and / or other electronic components or circuits, to generally control the system (10). The controller (8) may include a processor programmed with software, which can be modified by a user of the system (10). The control circuit / electronics (8) operates the aerosol generator (4) using power from the battery (5) when vapor is required. At this time, the user inhales into the system (10) through the mouthpiece (6), and air A enters through one or more air inlets 9 in the wall of the device (20) (the air inlets may be located alternatively or additionally on the article (30)).When the aerosol generator (4) is operated, it vaporizes the source liquid supplied from the reservoir (3) to generate the aerosol by drawing the vapor into the air flowing through the system (10), and then the user inhales it through the opening (7) in the nozzle (6). The aerosol is carried from the aerosol generator (4) to the nozzle (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 into the nozzle (6). The device (20) and the article (30) are separate connectable parts that can be separated from each other by pulling apart in a direction parallel to the longitudinal axis, as indicated by arrow (C) in Figure 1. Components (20), (30) are joined when the system (10) is in use by cooperating couplings or connecting elements (21), (31) (e.g., a screw or bayonet fitting) that provide mechanical and, in some cases, electrical connectivity between the device (20) and the article (30). Electrical connectivity is required if the aerosol generator (4) is an ohmic heating-operated heater, so that current can pass through the aerosol generator (4) when it is connected to the battery (5). In systems using inductive heating, electrical connectivity can be omitted if no electrically powered parts are located on the article (30).An inductive working coil can be housed in the device (20) and powered from the battery (5). The article (30) and the device (20) can be shaped so that, when connected, the aerosol generator (4), acting as an inductive susceptor, is adequately exposed to the flux generated by the coil, thereby inducing a current flow in the aerosol generator material. Other examples of electrically powered aerosol generators include a vibrating mesh that ejects liquid droplets, for example, operating via the piezoelectric effect. The design in Figure 1 is merely an example arrangement, and the various parts and features can be distributed differently between the device (20) and the article (30), and other components and elements can be included.The two sections can be connected end-to-end in a longitudinal configuration, as in Figure 1, or in a different configuration, such as a parallel, side-by-side arrangement. The system may or may not be generally cylindrical and / or generally longitudinal in shape. One or both sections or components may be intended to be discarded and replaced when depleted (the tank is empty or the battery is discharged, for example), or they may be intended for multiple uses enabled by actions such as refilling the tank and recharging the battery. The modalities and examples in this description are applicable to any of these configurations and other configurations of which a person skilled in the art will be aware. Some aerosol delivery system designs have a reservoir arrangement in the consumable component from which non-solid aerosol-generating material is dispensed by forcing it out through 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 an inward thrust force to reduce the internal volume of the reservoir where the material is stored. The volume reduction increases the pressure on the material in the reservoir, and some material exits the reservoir through the outlet to reduce the pressure to an equilibrium level. The thrust force is applied by a thrust applicator acting on the movable wall on an outer side, as opposed to an inner side facing the interior of the reservoir's internal volume. The thrust applicator, A reservoir arrangement of this type can provide several advantages compared to a fixed-volume reservoir that develops an internal air volume (headspace) as the aerosol-generating material is consumed. Leaks can be reduced, since a headspace can change volume due to changes in ambient pressure or temperature, forcing material out of the reservoir at unwanted times. The viscosity requirements of the aerosol-generating material are relaxed; the material does not need to flow, only be able to be displaced. The system is orientation-independent, as it does not rely on gravity for fluid flow out of the reservoir. Rather, the material is pushed out of the reservoir on demand by operating the push applicator at appropriate times, so the system can be used upside down for extended periods, for example, if the user is reclining. Similarly, Figure 2 shows a simplified schematic representation of an example of such an aerosol delivery system. As in the example in Figure 1, the system comprises a device (20) and a consumable (30), configured to connect to each other in a longitudinal arrangement indicated by arrow C. The device (20) and the consumable (30) are shown in a decoupled configuration to better illustrate the division of parts between the components. The consumable (30) has an outer wall (11), which may have a cylindrical cross-section, defining an internal space, part of which acts as a reservoir (3) for storing aerosol-generating material in an internal volume. This volume is also bounded by a fixed wall (13) extending transversely through the interior space of the outer wall (11) near the nozzle end (6) of the consumable (30), and by a movable wall (12) also extending transversely through the interior space of the outer wall (11) near the connection 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) through which the aerosol-generating material stored in the reservoir (3), indicated by arrow L, can be dispensed.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 nozzle (6), which acts on the material to generate a vapor in any known manner, such as by heating. The aerosol-generating material L may be dispensed directly onto the aerosol generator (4), or in the vicinity of the aerosol generator in a region where the action of the aerosol generator (4) extends, or onto or within some form of aerosol-generating material transport element, such as a wick, porous element, or capillary tube that transports material from the outlet (15) to or near the aerosol generator (4). The movable wall (12) is not fixed and is configured to move or slide on the inner surface of the outer wall (11) in an inward direction, i.e., toward the fixed wall (13). This movement reduces the internal volume of the tank (3), increases the pressure in the aerosol-generating material, and causes some of the material to be displaced through the outlet (15). A suitable sealing arrangement is provided around the perimeter of the movable wall (12) to reduce or prevent leakage of the aerosol-generating material through the joint between the movable wall (12) and the outer wall (11), thereby providing an effective internal storage volume that is watertight except for the outlet (15). A rubber or silicone gasket could be suitable, for example, or the movable wall (12) itself could be made of a flexible, elastic material of this type.This inward movement of the movable wall, indicated by the arrow (W), is effected by a thrust force applied to the outer surface of the movable wall (12), that is, the surface not facing the interior of the tank. The thrust force acts substantially perpendicular to the plane of the movable wall (which in this example is flat, but is not necessarily so), along with the desired inward direction of the movement (W). Accordingly, the supply of aerosol-generating material from the reservoir (3) can be considered analogous to the ejection of liquid from a syringe, where the outer wall (11) of the consumable (30) corresponds to the syringe barrel, and the movable wall (12) corresponds to the syringe plunger. The term “plunger” may hereafter be used to refer to the movable wall (12). Note that a tank with a reducible volume created by a movable wall does not need to be configured as shown in Figure 2. For example, dedicated boundary walls can be provided to define the sides of the tank, so that the tank is mounted within the outer wall of the consumable and does not share walls with it. The outlet can be located differently; for example, it does not need to be centered within the fixed end wall but could be to one side. If the tank has its own side walls located within the outer consumable wall, the outlet could be on the side wall instead of the fixed end wall.This may be more suitable for some aerosol generator configurations, but an outlet in the fixed-end wall may be preferable as it allows for better and more complete expulsion of all material from the tank. This is achieved by the moving wall traveling the entire length of the tank and in contact with the fixed wall, thus reducing the internal storage volume substantially to zero. For configurations with dedicated tank boundary walls, the tank can be replaced separately when empty. In this case, the tank can be considered the consumable or consumable item, and the generator... The aerosol can and nozzle may be contained within the device. Alternatively, the canister could be a consumable item that can be replaced within the larger consumable (30), which in turn can be replaced within the device to form the system. The examples in this description are generally applicable to configurations in which the canister can be removed and replaced with respect to the device, regardless of the nature and quantity of other parts that can be replaced in the same housing as the canister. The device (20) comprises a battery (5) and a controller or control electronics (8) as before. In addition, the device comprises a push applicator (14), which is a device, apparatus, means, or other operable arrangement for providing and applying the required push force (P) to the movable wall (12) when the device (20) is engaged with the consumable (30). The push applicator (14) can operate under the control of the controller (8) to provide the amount of push force (P) necessary to dispense a required volume or portion of material from the reservoir at an appropriate time. Typically, this will occur when a user requires aerosol delivery—in other words, wishes to inhale or “inflate” the system. At the same time, or very shortly thereafter, the aerosol generator (4) is also activated by the controller (8) to vaporize the dispensed portion of material.The push applicator (14) and aerosol generator (4) can be activated by the controller (8) in response to the user's actuation of an input control element on the outside of the system, such as a button or switch (not shown), or in response to airflow through the system detected by an airflow sensor or an air pressure sensor (puff detector, also not shown) when the user begins to inhale through the mouthpiece (6).The push applicator (14) can be activated for a predetermined time period to dispense a predetermined volume of material, such as an amount that typically corresponds to the amount of steam consumed in an average puff, or it can be activated for the duration of the puff, i.e., until the end of the puff is detected by the user ceasing activation of the inlet control element or the cessation of airflow, or for some other time, or to provide a predetermined amount of force. The push applicator (14) can take a variety of forms. Figure 3 shows a simplified schematic side view of an example of a push applicator (14) acting on a plunger (12). The push applicator (14) is a mechanical device comprising a drive rod (41) capable of advancing the push force (P) in the required direction (a push direction, toward the plunger (12)) and pressing or pushing against the outer surface of the plunger (12) to move it inward in direction (W). The rod (41) is driven by a suitable mechanical drive mechanism. Examples of such mechanisms will be obvious to those skilled in the art, such as a worm gear, where the rod (41) may be the worm gear or be coupled to the worm gear, or the rod (41) may be in the form of a lead screw or be coupled to a lead screw. The motion is provided by a motor in a drive assembly (40) to which the rod (41) is coupled.The control unit (40) is operated, using electrical power from the device's battery, to move the rod (41) as required in response to control signals 16 from the controller (8). Specifically, the drive assembly (40) is operable to advance the drive rod in the push direction, bringing it closer to and then into contact with the plunger (12). In this example, the rod (41) terminates at its distal end, away from the drive unit (40), in a shaped engagement member (42) that makes contact with the outer surface of the plunger (12). The engagement member (42) may, for example, be made of an elastic material such as rubber, silicone, or plastic, to absorb the impact when the rod (41) first engages with the plunger (12) and to minimize shock waves and pressure disturbance within the tank.In the illustrated example, the coupling member (42) is wider than the rod (41). This provides a large contact area with the plunger (12) while reducing the material and weight of the rod (41), saving costs, and reducing the power required to drive the rod (41). However, the coupling member (42) and the rod (41) can be the same width. To aid in the engagement of the rod (41) with the plunger (12), the coupling member can have a shape complementary to the shape (43) provided on the outer surface of the plunger (12). In this example, the plunger has a concavity (43) on its outer surface, and the coupling member (42) is convex and shaped to fit into the concavity (43). Other shapes can be used as preferred, including a convex plunger surface and a concave rod end.The piston (12) can be formed directly on or within the piston (12), or it can be provided on a shaped member (not shown) mounted on the outer surface of the piston (12). Such a shaped member can be formed from a strong material in addition to or instead of the engagement member. In use, the drive rod (41) has an initial retracted position in which it is fully or largely housed within the device (20). After the device (20) is connected to the consumable (30), the drive assembly (40) advances the rod (41) in the push direction to make contact with, or be very close to, the plunger (12). The rod (41) is thus positioned to push against the plunger (12) to enable rapid dispensing from the reservoir when aerosol-generating material is required. This initial advancement can occur in response to the detection of the consumable (30) connected to the device (20) by a detector (not shown) which 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) so that it advances an appropriate distance, thereby applying the thrust force (P) against the plunger (12) to move it inward W. After each puff, the rod (41) can maintain its current position against or in contact with the plunger (12), ready to continue advancing when the next puff is requested. Once the reservoir has been emptied, which could be detected by sensing maximum extension or advancement of the rod (41) from the drive 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 allow the consumable (30) to be disconnected from the device (20) for replacement. In some systems, it may also be possible to detach the consumable from the device before it is completely empty and reinstall it later to consume the remaining aerosol-generating material. This allows the user to switch between different types of aerosol-generating material, such as changing the flavor, without having to wait until the reservoir is empty or discard a partially consumed consumable. Additionally, consumables may be supplied with varying volumes of material. ML / to aerosol generator, as smaller sample quantities of material to allow the user to test different types. In these various circumstances, the plunger position is not fixed for all consumables that may be connected to the device. Consequently, it is not feasible, when a consumable is connected to the device, for the controller to simply cause the push rod to advance a set distance so that it is positioned to push against the plunger. Instead, the drive rod must be advanced until it is correctly positioned to push against the plunger, regardless of the plunger's position and, therefore, the gap between the drive rod end and the plunger when the consumable and device are coupled. The amount of initial advance required before dispensing is thus variable. The subsequent incremental advance of the drive rod to push the plunger and dispense aerosol substrate material can be a fixed distance each time, corresponding to a fixed dose of material, and is normally carried out at a relatively low speed, since the distances to be covered are small and to achieve smooth dispensing and avoid jerky plunger movements. If this same speed is used to move the drive rod during the initial advance, it can take an unacceptably long time for the system to reach an operational state, ready for aerosol generation. This is particularly true with a nearly empty reservoir, where the gap between the drive rod and the plunger is large. Consequently, it is proposed that the drive assembly be configured to advance the drive rod at more than one speed, under the direction of the controller. A first speed is enabled to move the drive rod from its initial retracted position toward the plunger and into the position to push against the plunger. A second speed is also enabled to move the drive rod when it is in contact with the plunger to push the plunger inward and dispense material from the reservoir. The first speed is faster (higher, larger, larger) than the second speed.In contrast, the second speed is slower (lower, smaller) than the first speed. Providing multiple drive speeds allows the system to become operational more quickly when the consumable is connected to the device. However, it's important to remember that the plunger's position is variable and unknown to the controller. Continuing the drive rod's movement at the first speed once it's in contact with the plunger is undesirable, as this will reduce the reservoir volume very rapidly and cause unwanted amounts of aerosol-generating material to be dispensed. Therefore, it's also proposed that the drive rod's proximity to the plunger be monitored, measured, or detected as the drive rod approaches the plunger at the first speed. When the proximity (the distance between the drive rod and the plunger) is detected to have decreased to a predetermined gap, the drive assembly stops operating at the first speed. Upon detection of this predetermined gap, the drive assembly can switch to the second speed, change to a speed slower than the first, or stop the drive rod's advance.The preset offset can be a positive value, where the drive rod separates from the piston, or it can be zero, where the drive rod is in contact with the piston. In this way, the drive rod can be moved at an appropriate speed depending on its offset from or contact with the piston. IVIA / 1 / any piston position, and avoiding rapid piston thrust. We can define a range of variables to describe the different combinations of positions and velocities. These are indicated and described with respect to the following highly schematic diagrams. Figure 4A shows a schematic representation of an actuating rod (41) and a piston (12). These two elements are in initial positions that arise when the consumable comprising the reservoir, and therefore the piston (12), is connected to the device comprising the actuating rod (12) (41). The end of the actuating rod (41) closest to the piston (12), which will engage with the piston (12) to push it, is in a retracted initial position (R) at a distance (d1) from the outer surface of the piston (12). The actuating rod (41) will advance toward the piston (12), and therefore move along the pushing direction, at the first speed (S1). The retracted position (R), from which the movement at the first speed (S1) is effected, is at a separation or offset from the piston that is greater than the predetermined offset mentioned above. Figure 4B shows the drive rod (41) and the plunger (12) after the drive rod (41) has traveled the distance (d1) so that its end is in contact with the plunger (12) and can push it along the pushing direction. To perform the pushing, the drive rod moves at the second speed (S2), which is slower than the first speed (S1). To bring the drive rod (41) from its retracted position (R) into contact with the plunger (12), proximity sensing is used as previously described. The distance (d1) can be traveled in one or more stages of movement, as shown in the following examples. Figure 4C shows the drive rod (41) and the plunger (12) in the positions reached according to a first example. The drive rod (41) has advanced at the first speed (S1) from the retracted position (R) to a position (X) where the gap between the end of the drive rod (41) and the plunger (12) is a predetermined separation (d2), which is considered to correspond to the proximity of the drive rod (41) to the plunger (12). When the drive rod (41) reaches the proximity position (X), its movement, controlled by the controller, is stopped. As mentioned earlier, the proximity position (X) can be set so that the predetermined gap (d2) has a positive value; in other words, there is still some distance separating the end of the drive rod (41) from the plunger (12), as shown in Figure 4C. Figure 4D shows the drive rod (41) and piston (12) positioned according to a second example. In this case, the proximity position (X) is adjusted to coincide with the outer surface of the piston (12), so that the drive rod (41) is in contact with the piston (12). In other words, the predetermined clearance (d2) is essentially zero. Thus, in this case, the drive rod (41) advances at the first speed (S1) until it makes contact with the piston (12), at which point the drive ceases at (S1). Figure 4D also indicates another parameter, Y, which is a position of the end of the drive rod (41) that is considered a position in which the drive rod (41) is positioned to push against the piston (12).This is defined by the position occupied by the drive rod (41) before the start of a pushing action during which it is driven at the slowest speed (S2) to move the plunger (12) and dispense material from the reservoir. In this example, positions Y and X are coincident. The fastest speed (S1) is used to move the drive rod (41) until it is in contact with the plunger (12). From this position, when aerosol generation is required, the drive rod (41) can be driven at the slowest speed (S2) to push against the plunger (12) immediately after the slower movement begins. Returning to Figure 4C, a third example is to again define X and Y as coincident, but with the non-zero positive value of the predetermined spacing (d2) shown in Figure 4C. Therefore, in this example, the drive rod (41) is positioned to push, at position (Y), to a position that is separate from the plunger (12). To effect the plunger push when aerosol generation is required, the drive rod (41) can then be advanced from position (Y) at the second speed (S2) until it makes contact with the plunger (12) and then further advanced at the second speed (S2) to move the plunger (12).Although this arrangement takes slightly longer to dispense aerosol-generating material from the reservoir due to the time required for the actuating rod (41) to travel the distance (d2) and make contact with the plunger (12), it may be preferable to the second example because it prevents the actuating rod (41) from impacting the plunger (12) at the first highest speed (S1). Such an impact could cause unwanted movement of the plunger or induce a pressure wave within the reservoir, both of which could result in the material being expelled from the reservoir at an undesirable time. From these examples, it will be seen that the position of the pushrod when considered to be “positioned to push against the piston” is defined to include the alternatives of being already in contact with the piston so that the movement of the pushrod immediately pushes the piston, and being positioned slightly away from the piston so that an initial movement is needed to make contact with the piston before the pushing action begins. This latter arrangement may include a small retraction of the pushrod after each pushing action to restore the slight separation; this can relieve pressure within the reservoir and reduce the risk of accidental fluid ejection that could result from physical shock or thermal expansion. Figure 4E shows the driving rod (41) and plunger (12) positioned according to a fourth example. In this case, the position (X) of the driving rod when it reaches the predetermined distance (d2) is different from the position (Y) of the driving rod when it is positioned to push the plunger (12). The predetermined distance (d2), which when reached causes the driving rod to stop moving at first speed (S1), is set to be greater than the separation of the driving rod (41) from the plunger (12) when the driving rod is positioned to push in position (Y). In other words, position (X) is farther from the plunger (12) than position (Y). To operate according to this example, the driving rod (41) advances at first speed (S1) from its retracted position (R) to the predetermined separation (d2) in position (X).Then, to position the drive rod (41) ready to push when aerosol generation is desired, the drive rod is advanced further to a third speed (S3) which is slower than the first speed (S1). Figure 4F shows the drive rod (41) and plunger (12) after movement at third speed (S3), when the drive rod (41) has reached position (Y), ready to push the plunger (12) when required for aerosol generation. Position (Y) is separated from the plunger by a distance (d3), which is less than the predetermined separation (d2). Then, when material distribution for aerosol generation is required, the drive rod (41) can be operated to advance and engage against the plunger (12) to push it at second speed (S2), as described with respect to Figures 3 and 4. The third speed (S3) used to move the drive rod (41) from the predetermined separation to its final Y position, ready to push, is preferably 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 in an operational 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 case of proximity sensing errors. Alternatively, the third speed (S3) may be slower than (S2). This may allow for more precise positioning of the drive rod at the push 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 set to zero. In other words, the drive rod is brought into contact with the plunger so that it is ready to push, as in the example in Figure 4. Therefore, the drive rod advances at the first speed (S1) to the predetermined space at position (X), and then at the lower third speed (S3) to cover the distance (d2) and make contact with the plunger at position (Y). It remains in this position until aerosol generation is required, and then the drive rod is actuated to advance at the second speed (S2) to move the plunger. In the examples where the location for pushing, the position (Y) of the driving rod, is separated from the piston (d3>0), the initial part of the pushing action in which the driving rod advances over the distance (d3) to reach the piston can be carried out at the second speed (S2), as stated 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). Based on the preceding description, it follows that, to achieve the proposed multi-speed or dual-speed actuation of the drive rod by the drive assembly, it is appropriate to detect the proximity of the drive rod to the piston. In this context, proximity is the separation or distance between the drive rod and the piston, or the separation of the drive rod from the piston. If proximity is detected while the drive rod is approaching the piston at the first speed, the predetermined distance from the piston can be established by comparing the detected proximity with the predetermined distance value. When the predetermined separation is reached, the advance of the drive rod at the first speed is stopped. This can be achieved by using a proximity sensing arrangement or a proximity detector that monitors the gap while the drive assembly moves the drive rod to first speed under the controller's control. The proximity detector can continuously or periodically output measured proximity values ​​to the controller. The controller repeatedly compares the most recent measured proximity value with a stored value for the predetermined gap. When the comparison determines that the measured proximity is substantially equal to the predetermined gap, the controller stops the drive assembly from moving the drive rod to first speed. Alternatively, the comparison can be performed to find a measured proximity that is slightly greater than the predetermined separation, so that the controller instructs the cessation of movement at first speed before the predetermined separation is reached. This allows for processing time and the time required to stop the drive rod (inertial effects, for example), so that when movement ceases, the drive rod has reached the predetermined distance. This can be useful in examples where the predetermined spacing is substantially zero (Figure 4D), to minimize the impact of the drive rod on the piston. In other cases, it may be sufficient to treat the predetermined spacing as a threshold and stop the advance at first speed when the comparison shows that the detected proximity is equal to or less than the predetermined spacing.This may be appropriate for periodic proximity measurements, so that no single measurement may exactly match the stored value for the default gap. Alternatively, the default gap could be defined as a range of gaps, and driving at first speed stops when the measured proximity value first falls within that range. To implement this, the device further comprises a proximity detector, configured to detect the separation or distance between the drive rod and the plunger. This can be the distance between the surface of the end of the drive rod and the outer surface of the plunger, as shown in the examples in Figure 4. Alternatively, depending on the nature and position of the proximity detector, the actual measured distance may be between some other part of the plunger and some other part of the drive rod. Provided the measurements are properly calibrated and the predetermined separation is set with reference to the two endpoints of the median distance, the precise configuration is not critical. Any form of proximity sensor may be employed, as will be evident to anyone skilled in the art.Some examples will be described below, but disclosure is not limited in this respect, and other forms of proximity sensor may be used if desired. Figure 5 shows a schematic representation of a first example of a proximity detector that can be used to measure or detect the separation of interest between the actuating rod and the plunger. The proximity detector comprises a capacitive sensor, where capacitance measurement is an established technology for proximity detection. The capacitance between a pair of conductive or dielectric elements (capacitor plates) is monitored, and this varies with the separation between the elements; therefore, the capacitance value is directly related to the separation between the elements.In the example of Figure 5, the capacitive sensor comprises a first capacitor plate (50) provided on or at the end face of the drive rod (41), for example, by forming a portion of the drive rod end of a suitable material, or by providing the surface of the drive rod end with a coating of a suitable material and an electrical connection (54) between the first plate (50) and the controller (8). A second capacitor plate (52) is provided on or at the outer face of the plunger (12), again as a portion of suitable material secured to the plunger or as a surface coating.The electrical connection (54) is configured so that the controller applies a small voltage to the first capacitor plate (50) (by connecting it to the battery in the device) when proximity measurements are required, and to query the capacitance (C) between plates (50) and (52) as the drive rod moves toward the plunger (12). The capacitance value (C)' corresponding to the predetermined separation (d2) can be stored in the controller's memory (8), and a comparison is made between the currently measured capacitance value (C) and the stored value (C') to determine when the drive rod (41) has reached the predetermined separation. Alternatively, the controller could be configured to convert the currently measured capacitance value (C) to its corresponding separation value and compare the separation value with a stored value of the predetermined separation.The conversion can be performed by calculation according to a stored formula that relates capacitance to spacing, or by reference to a lookup table, for example, comparing the spacing value to a stored default spacing value. The capacitor plates can be configured differently if desired. For example, the plunger (12) itself can be made of a suitable conductive or dielectric material. Alternatively, a portion of a suitable material could be embedded within the plunger or provided on the inner surface of the plunger, where a coating of a suitable material could also be used. These arrangements can be used if the plunger is made of a non-conductive material unsuitable for use as a capacitor plate and can be useful for 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) could be embedded behind the surface of the end of the drive rod (41) or provided with a non-conductive protective coating. Figure 6 shows a schematic representation of a second example of a proximity detector using capacitance detection. In this example, the first capacitor plate (50) is provided in, on, or otherwise associated with the actuating rod (41), as in the example in Figure 5. The other element acting as the second capacitor plate (52) is the aerosol-generating material stored in the reservoir (3). Therefore, the capacitance (C) is measured between the first capacitor plate (50) and the end surface or end portion of the aerosol-generating material in the reservoir (3) immediately behind the plunger (12). The plunger (12) must be made of a non-conductive material, or at least a material that is substantially less conductive / dielectric than the aerosol-generating material, so that it is effectively invisible to the capacitance measurement. Figure 7 shows a schematic representation of a third example of a proximity detector. The detector in this case comprises a time-of-flight detector. A transmitter / receiver or a sensor or emitter / detector module (56) is mounted on or at the end face of the actuating rod (41), or alternatively on a side surface of the actuating rod (41) facing the plunger (12). The sensor (56) comprises a transmitter / emitter (56a) configured to transmit a pulse of light (or other electromagnetic energy such as a radio wave) or sound (58T) toward the plunger (12). The sensor (56) is controlled by the controller (8) via a connection (54), to be activated to emit pulses at known emission times when proximity detection is required.At least a portion of the energy in the transmitted pulse (58T) is reflected or bounced off the surface of the plunger (12) to provide a return portion (58R), which is detected by a receiver / detector (56)b in the device (56). The detection time is recorded, and the round-trip duration for the pulse (to the plunger and back) is calculated from the transmission time and the detection time—this is the time of flight. Since the transmission speed of the pulse is known (since the speeds of sound and electromagnetic radiation are fixed), the distance the pulse has traveled can be calculated. From this, the proximity between the drive rod (41) and the plunger (12) can be calculated as half the round-trip distance. These calculations can be performed on the sensor (56) so that a signal representing the currently measured proximity value can be sent to the controller (8) via connection (54).Alternatively, and more conveniently, the sensor (56) can simply communicate to the controller (8) that the pulse has been detected, and the calculations can be performed in the controller (8). The detected proximity can be compared with a predetermined space stored in the controller's (8) memory to determine when the drive rod (41) has reached the position corresponding to the predetermined separation so that it can cease movement at the first speed. Alternatively, a round-trip time of the pulse (time of flight) corresponding to the predetermined separation can be stored in memory and compared with the measured round-trip time to identify arrival at the predetermined separation. A time-of-flight proximity detector can also be implemented by placing the sensor (56) on the plunger and reflecting pulses from the advance of the pushrod, or by placing one part of the transmitter or receiver on the pushrod and the other part of the transmitter or receiver on the plunger (so that the pulse travels through space for direct detection, rather than undergoing reflection after a round trip). However, these arrangements can be more complex to implement since electrical connectivity to parts in the consumable is required. Proximity sensors, such as capacitive or time-of-flight sensors, can be used to continuously monitor the gap between the pushrod and the plunger. They can provide measurements that allow monitoring of a predetermined positive gap—in other words, a predetermined gap where the pushrod separates from the plunger. A predetermined zero gap, where the pushrod is in contact with the plunger, can also be detected by looking for a sudden change in the measured response resulting from the contact. For example, in time-of-flight detection, the return pulse will become undetectable when the pushrod bottoms out with 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 plates of the capacitor in a capacitive sensor make contact, as the capacitive capacitance is lost and the capacitance drops to zero. Alternatively, if at least one of the plates is located away from the adjacent surfaces of the drive rod and 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. Other alternative arrangements are capable of detecting a predetermined zero separation, i.e., when the push rod makes contact with the plunger, implementing proximity detection based on the operation of an electric motor included in the pusher assembly. Figure 8 shows a simplified schematic representation of a proximity sensing arrangement based on motor control. The drive assembly (40) includes a motor (60) that operates in response to control signals from the controller (8) to extend and retract the drive rod (41) at the various speeds described above. The drive assembly (40) also includes a sensor (62) that acts as a proximity sensor in that it is configured to detect a condition indicating that the drive rod (41) is making contact with the plunger (12). The detection of this condition can be fed to the controller (8), which in turn acts to stop the movement of the drive rod (41) at the first speed. When the drive rod makes contact with the plunger, the load on the motor increases. More force is required to keep the drive rod moving, as it is now pushing against the plunger. The motor now has to work harder to move both the drive rod and the plunger. The increased load causes the motor to draw more current from the device's battery. Consequently, when impact occurs, there is a surge in the current drawn by the motor. Therefore, the detector (62) can be a current detector that monitors the current drawn by the motor. The detector will detect a current spike, such as a sudden spike or surge, and this condition will be communicated to the controller (8) to shut down the first drive speed of the drive rod.Other engine operating parameters change with increasing load, so they can be monitored similarly to detect when contact is made between the pushrod and the piston. For example, the engine's rotational speed will change for a given power output. Other parameters may be obvious to someone skilled in the field and can, alternatively, be controlled as desired. The pushrod may be fitted with a compressible element at its end, such as a spring or a piece of foam. This will compress when it makes contact with the piston, causing a more gradual change in engine load. However, this change can still be detected, and the pushrod will stop (or slow down) while compression is still in progress to prevent further movement of the piston. Figure 9 shows a flowchart of steps in an example method for operating a push assembly, such as a drive rod, in a device of an aerosol delivery system according to this disclosure. In a first step (S1), a consumable having a syringe-like reservoir with a movable wall or plunger is connected or attached to a device to form an aerosol delivery system. In a second step (S2), a drive rod or similar push applicator occupying a retracted position in the device advances or moves toward the plunger at a first speed. While the movement at the first speed is in progress, the gap between the drive rod and the plunger is detected or measured so that the gap can be controlled, in a step (S3).Next, in step (S4), gap control is used to detect when the gap reaches a predetermined level. This could be, for example, zero gap, where the drive rod is in contact with the plunger, or a positive gap, where there is a small separation between the drive rod and the plunger. Once the predetermined gap is reached, in step (S5), the drive rod advances at the first speed, in response to the achievement of the predetermined gap. Subsequently, when aerosol delivery is required, the method proceeds to step (S6), where the drive rod advances at a second speed, which is slower than the first speed, to push against the plunger and move it inward.This reduces the volume of the tank and causes the aerosol-generating material in the tank to be expelled through an outlet in the tank, thus making the material available to be vaporized. More generally, the dual-speed drive concept for the drive rod can be implemented without proximity sensing. For example, if the consumable is configured so that it can only be attached to a device when the reservoir is full, and the plunger's position is therefore fixed between consumables, the distance the drive rod must move from its retracted position to the location where it pushes against the plunger is always constant for each consumable. Consequently, the drive rod can advance at the first speed to cover the necessary distance. Subsequently, when aerosol generation is desired and aerosol-generating material needs to be dispensed from the reservoir, the drive rod advances at the second, slower speed to push the plunger forward and displace the material through the reservoir outlet.The motor's operation to move the drive rod the required distance at first speed could be based on a number of motor revolutions known to correspond to that distance, for example. Alternatively, an encoder could be used to track the distance. Another option is to run the motor at first speed for a fixed time corresponding to the distance, but this approach can be less robust since factors such as differences in available battery voltage or variations in friction would cause variations in the distance the drive rod travels in the fixed time. Accordingly, the example method in Figure 9 can be implemented without steps (S3) and (S4), and a device component for use with a consumable component having a syringe-type reservoir with a plunger can be implemented with a push applicator as a two-speed actuated drive rod, without a proximity detector. In all examples and configurations, the various speeds, particularly the first and second speeds, can be selected considering the overall design of the aerosol delivery system to achieve the desired reduced speed for dispensing the aerosol-generating material, along with minimal delay in engaging the drive rod and plunger after the device and consumable are connected. The slower second speed may be a function of the power output for the system selected by the user, as it is related to the mass of aerosol-generating material that must be dispensed for vaporization. The absolute value of the second speed will depend on the aspect ratio of the consumable and the cross-sectional area of ​​the reservoir, as this determines the amount of aerosol-generating material dispensed per given distance traveled by the plunger. The preceding examples have been described in terms of a controller that positively controls the motor to operate at several different speeds when the drive rod is known to be in any of the corresponding positions. However, this positive control may not be necessary, and the required second, slower speed may arise by default as a consequence of the motor's 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 by the drive rod. When the drive rod makes contact with the plunger, the load on the motor increases as it works to push the plunger and displace the aerosol-generating material out of the tank, and if the power is maintained at the same level, the speed will decrease, thus producing the second, slower speed by default. The various embodiments described herein are presented only to aid in understanding and teaching the claimed features. These embodiments are provided only as a representative sample of the embodiments and are not exhaustive and / or exclusive. It should be understood that the advantages, embodiments, examples, functions, features, structures, and / or other aspects described herein should not be considered limitations on the scope of the invention as defined in the claims or limitations on equivalents to the claims, and that other embodiments may be used and modifications may be made without departing from the scope of the claimed invention. Various embodiments of the invention may properly comprise, consist of, or essentially consist of appropriate combinations of the elements, components, features, parts, steps, means, etc., described other than those specifically described herein.Furthermore, this disclosure may include other inventions not currently claimed, but which may be claimed in the future.

Claims

1. A device component for an aerosol delivery system, the device component comprising: an actuating 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 sensor configured to detect a separation of the actuating rod from the plunger; a transmission assembly operable for advancing the actuating 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 the 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 first speed from a clearance between the drive rod and the plunger that exceeds a predetermined clearance, and to stop advancing the drive rod at first speed in response to the detection of a clearance substantially equal to or less than the predetermined clearance.

2. A device component according to claim 1, wherein the controller is configured to stop advancing the drive rod at the first speed when the drive rod is positioned to push against the piston.

3. A device component according to claim 1, wherein the controller is configured, after ceasing to advance the drive rod at the first speed, to operate the drive assembly to advance the drive rod at a speed slower than the first speed to position the drive rod to push against the plunger.

4. A device component according to claim 3, wherein the slowest speed is the second speed.

5. A device component according to any of claims 2 to 4, wherein, when the drive rod is positioned to push against the plunger, the drive rod is in contact with the plunger.

6. A device component according to any of claims 2 to 4, wherein, when the drive rod is positioned to push against the plunger, the drive rod is separated from the plunger to contact the plunger by operating the drive assembly to advance the drive rod at the second speed or another speed slower than the first speed when it is required that the aerosol generating material be displaced from the reservoir.

7. A device component according to any of claims 2 to 6, wherein the controller is further configured to operate the drive assembly to advance the drive rod to the second speed when it is required that the drive rod against the plunger and the aerosol generating material be moved from the reservoir.

8. A device component according to any of claims 1 to 7, and further configured to connect to a consumable component of an aerosol delivery system, the consumable component comprising the movable plunger and the reservoir for storing aerosol-generating material, and the drive rod being operable to push against the plunger when the device component is connected to the consumable component.

9. A device component according to any of claims 1 to 8, wherein the proximity detector comprises a capacitive sensor mounted on the drive rod for detecting a capacitance between the sensor and an element comprising or contained in the plunger or reservoir, the predetermined separation corresponding to a particular capacitance value.

10. A device component according to any of claims 1 to 8, wherein the proximity detector comprises a time-of-flight sensor mounted on the drive rod for measuring a distance from the drive rod to the plunger, the predetermined separation corresponding to a particular distance.

11. A device component according to any of claims 1 to 8, wherein the drive assembly comprises an electric motor, and the proximity sensor comprises a detector operable to detect a change in an electrical parameter associated with the electric motor produced when the drive rod being advanced to the first speed impacts the plunger, the predetermined separation being a separation of zero.

12. A device component according to claim 11, wherein the detector comprises a current detector operable to detect an increase in the current consumed by the electric motor when the impeller strikes the plunger.

13. An aerosol delivery system comprising a device component according to any of claims 1 to 12, 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 the aerosol-generating material through an outlet of the reservoir when pushed by the drive rod of the device component.

14. A method for dispensing aerosol-generating material from a reservoir in an aerosol delivery system; the method comprising: advancing a drive rod in a thrust 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 gap between the drive rod and the plunger that exceeds a predetermined gap of the drive rod from the plunger; monitoring the gap of the drive rod from the plunger during advancement at the first speed; ceasing advancement at the first speed when the control indicates that the gap is substantially equal to or less than the predetermined gap;and subsequently, when it is required that the aerosol generating material be displaced from the reservoir, advance the drive rod against the plunger to push the plunger to displace the aerosol generating material through the outlet, at a second speed that is slower than the first speed.; 15. A device component for an aerosol delivery system, the device component comprising: an actuating 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 transmission assembly operable for advancing the actuating 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 the 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 first speed from a gap between the drive rod and the plunger that exceeds a predetermined gap, and to stop advancing the drive rod at first speed when the gap between the drive rod and the plunger is substantially equal to the predetermined gap; and to operate the drive assembly to advance the drive rod at second speed to move the plunger to displace the aerosol-generating material when aerosol-generating material is required.

16. A method for dispensing aerosol-generating material from a reservoir in an aerosol delivery 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 clearance between the drive rod and the plunger that exceeds a predetermined clearance of the drive rod from the plunger; ceasing to advance at the first speed when the clearance between the drive rod and the plunger is substantially equal to the predetermined clearance; and subsequently, when it is required that the aerosol-generating material be displaced from the reservoir, advancing the drive rod against the plunger to push the plunger to displace the aerosol-generating material through the outlet, at a second speed that is slower than the first speed.

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