The present disclosure relates to a vapor provision device, e.g. an e-cigarette.
Many electronic vapor provision systems, such as e-cigarettes and other electronic nicotine delivery systems, are formed from two main components—a cartridge, e.g. a cartomizer, and a control unit. The cartridge generally includes a reservoir of liquid and will often also include an atomizer for vaporizing the liquid, although in some cases the atomizer may be included in the control unit. A cartridge that contains an atomizer is sometimes referred to as a cartomizer. The atomizer is often implemented as an electrical (resistive) heater, such as a coil of wire. The control unit generally includes a battery for supplying power to the atomizer. In operation, the control unit may be activated, for example by detecting when a user inhales on the device and/or when the user presses a button, to provide electrical power from the battery to the heater. This activation causes the heater to vaporize a small amount of liquid from the reservoir, which is then inhaled by the user.
This type of e-cigarette therefore generally incorporates two consumables, firstly the liquid to be vaporized, and secondly power in the battery. Regarding the former, once the reservoir of liquid has been exhausted, the cartomizer may be discarded to allow replacement with a new cartomizer. Regarding the latter, the control unit may provide some form of electrical connector for receiving power from an external source, thereby allowing the battery within the e-cigarette to be re-charged.
Although e-cigarettes have developed rapidly over the past few years, there remain areas where it is desirable to improve the operability and user experience for such devices.
Various embodiments provide a mouthpiece for a vapor provision having a length direction corresponding to the direction of insertion of the vapor provision into the mouth of a user, a width direction corresponding to the direction along the lip-line of the user, and a depth direction corresponding to the opening direction of the lips of the user. The mouthpiece comprises first and second opposing faces and an exit hole located between the first and second opposing faces, wherein the opposing faces are approximately planar and lie within or slightly inclined to a plane defined by the longitudinal direction and the width direction.
In some embodiments, each of the opposing faces has a width which is greater than its length. In some embodiments, each of the opposing faces has a continuously curved section adjacent the exit hole of the mouthpiece, wherein the curvature lies substantially within the plane defined by the longitudinal direction and the width direction. In some embodiments, the mouthpiece further comprises a channel located between the first and second opposing faces, the channel extending in a width direction and having an indentation in the length direction, wherein the exit hole is located in said channel.
Various embodiments of the disclosure will now be described in detail by way of example only with reference to the following drawings:
For ease of reference, the x and y axes are marked in
We further assume a z axis (not shown in
The cartomizer 200 and the control unit 300 are detachable from one another by separating in a direction parallel to the y-axis, but are joined together when the device 100 is in use so as to provide mechanical and electrical connectivity between the cartomizer 200 and the control unit 300. When the e-liquid in cartomizer reservoir 270 has been depleted, the cartomizer 200 is removed and a new cartomizer is attached to the control unit 300. Accordingly, the cartomizer 200 may sometimes be referred to as the disposable portion of the e-cigarette 100, while the control unit 300 represents the re-usable portion.
The cartomizer 200 comprises two main portions (at least from an external viewpoint). In particular, there is a lower or base portion 210 and an upper portion 220. The upper portion 220 provides the mouthpiece 250 of the e-cigarette 100, as described in more detail below. When the cartomizer 200 is assembled with the control unit 300, the base portion 210 of the cartomizer 200 sits within the control unit 300, and hence is not externally visible, whereas the upper portion 220 of the cartomizer 200 protrudes above the control unit 300, and hence is externally visible. Accordingly, the depth and width of the base portion 210 are smaller than the depth and width of the upper portion 220, to allow the base portion 210 to fit within the control unit 300. The increase in depth and width of the upper portion 220 compared with the base portion 210 is provided by a lip or rim 240. When the cartomizer 200 is inserted into the control unit 300, this lip or rim 240 abuts against the top of the control unit 300.
As shown in
As also shown in
The top view further shows a hole 280 in the mouthpiece 250 which represents the air outlet from the cartomizer 200. Thus in operation, when a user inhales, air enters the cartomizer 200 at the bottom through inlet 214, flows through the atomizer, including past the heater, where it acquires vapor, and then travels up the centre of the cartomizer to exit through air outlet 280.
It will be appreciated that the dimensions shown in
The front and rear faces 251 provide relatively large surfaces onto which the lips of a user can be placed. For example, we can consider the front face 251 to provide a surface for engaging the upper lip, and the rear face 251 to provide a surface for engaging the lower lip. In this configuration, we can regard the height (y axis) of the e-cigarette 100 as defining a longitudinal or length axis extending away from the user's mouth, the width of the e-cigarette 100 (the x axis) as running parallel to the line between a user's upper and lower lips, and the depth of the e-cigarette 100 (the z axis) as running parallel to the direction of separation of the user's upper and lower lips.
The height (or length) of the front and rear mouthpiece faces 251 (approximately 17 mm in the particular embodiment of
It will be appreciated that these sizings are again provided by way of example only, and may vary according to the particular implementation. Typically the height of the mouthpiece faces 251 is in the range 8-24 mm, for example 12-20 mm, while the width of the mouthpiece faces 251 is at least 20 mm, and for example at least 25 mm. Typically, the width of the mouthpiece faces 251 is at least 30%, and for example at least 50%, greater than the length of the mouthpiece faces 251.
This shape and sizing of the mouthpiece 250 allows the lips of user to engage the mouthpiece 250 for inhalation with much less distortion from the normal resting position of the mouth—e.g. there is no need to purse the lips, as for a straw or conventional cigarette having a small circular mouthpiece. This makes using the mouthpiece 250 of the e-cigarette 100 a more relaxing experience, and also may help to ensure a more consistent seal between the mouth and the mouthpiece 250.
In addition, e-cigarette 100 (like many other e-cigarettes) uses a sensor to detect airflow through the device, i.e. a user puff, which can then trigger operation of the heater to vaporize the liquid. The device has to discriminate between the airflow caused by a user puff, and other forms of airflow or pressure changes that arise due to other actions or circumstances—e.g. movement of the e-cigarette 100 through the air, being on a railway train which enters a tunnel, etc. Having a consistent seal between the mouth and the mouthpiece 250 can help the device 100 provide better discrimination of an actual inhalation, and so reduce the risk of unintentional activation of the heater.
Furthermore, some e-cigarettes use sensor measurements of the airflow through the device not only to initiate activation of the heater, but also to provide dynamic control of the heater (or other components of the e-cigarette). For example, as the measured airflow increases, the heater may be provided with more power, firstly to compensate for the cooling effect of the increased airflow, and/or secondly to vaporize more liquid into the increased airflow. Having a consistent seal between the mouth and the mouthpiece 250 can again help to improve the reliability and accuracy of this dynamic control.
As can be seen in the two side views of
In addition, with reference to the side views of
Typically the span of the channel, as measured parallel to the z axis, is in the range 2-10 mm, and for example within the range 3-6 mm. This relatively narrow depth helps the overhang of the mouthpiece faces 251 to protect the opening 280, and is also compatible with the generally planar configuration of the cartomizer (i.e. the smaller sizing in the z direction). Typically, the channel has an approximately U-shaped profile, with the depth or indentation of the valley 284 below the overhang (as measured in the y direction) being approximately equal to the span of the valley 284 as given above. This level of indentation allows the overhand of the opposing mouthpiece faces 251 to provide reasonable protection for the exit hole 280.
Typically the valley 284 extends for a distance of at least 6 mm, and for example at least 10 mm in the width direction. Note that the exit hole 280, which lies in the middle of the valley, usually halfway along, has a generally circular shape. The size of the exit hole 280 is therefore primarily constrained by the span of the channel, rather than its extension in the width direction, and hence the exit hole 280 may occupy only a relatively small portion of the overall valley 284. It will be appreciated that having the channel extend in the width direction reflects the shaping of the mouthpiece faces 251, which also have their greatest extent in the width direction.
As shown in the central view of
Typically, the curved section is substantially parallel to the width direction adjacent the exit hole 280 of the mouthpiece 250, and the curvature extends for an angle of at least 30 degrees, and for example at least 45 degrees, around towards the length direction on either side of the exit hole 280. In other words, the curved section represents a total rotation of at least 60 or 90 degrees, which as shown in
The cap 480 is formed from substantially rigid plastic such as polypropylene and provides the base portion 210 of the cartomizer 200. The cap 480 is provided with two holes 260, 261 on each side (only one side is visible in
Above the end cap 480 is located the PCB 470, which includes a central air hole 471 to allow air to flow through the PCB 470 into the atomizer (the end cap 480 is likewise provided with a central air hole, not visible in
Above the PCB 470 is located the primary seal 460, which has two main portions, an upper portion which defines (in part) an atomizer chamber 465, and a lower portion 462 which acts as an end seal for the reservoir 270. Note that in the assembled cartomizer 200, the reservoir of e-liquid is located around the outside of the atomizer chamber 465, and the e-liquid is prevented from leaving the cartomizer 200 (at least in part) by the lower portion 462 of the cartomizer plug 460. The cartomizer plug 460 is made from a material that is slightly deformable. This allows the lower portion 462 to be compressed a little when inserted into the shell 410, and hence provide a good seal to retain the e-liquid in reservoir 270.
Two opposing side walls of the atomizer chamber 465 are provided with respective slots 569 into which the wick 440 is inserted. This configuration thereby ensures that the heater 450, which is positioned on the wick 440, is located near the bottom of the atomizer chamber 465 to vaporize liquid introduced into the atomizer chamber 465 by wick 440. In some embodiments, the wick 440 is made of glass fiber rope (i.e. filaments or strands of glass fiber twisted together), and the heater coil 450 is made of nichrome (an alloy of nickel and chromium). However, various other types of wick 440 and heater are known and could be used in the cartomizer 200, such as a wick 440 made out of porous ceramic, and/or some form of planar heater (rather than a coil). Note that although
The cartomizer plug 460 and the wick/heater assembly 500 are surmounted by the inner frame 430, which has three main sections. The inner frame 430 is substantially rigid, and may be made of a material such as polybutylene terephthalate. The lowermost section 436 of the inner frame 430 covers the lower portion 462 of the cartomizer plug 460, while the middle section 434 completes the atomizer chamber 465 of the cartomizer plug 460. In particular, the inner frame 430 provides the top wall of the atomizer chamber 465, and also two side walls that overlap with the two side walls of the atomizing chamber 465 of the cartomizer plug 460. The final section of the inner frame 430 is an airflow tube 432 that leads upwards from the top wall of the atomizing chamber 465 (part of the middle section 434) and connects with the mouthpiece hole 280. In other words, tube 432 provides a passage for vapor produced in the atomizing chamber 465 to be drawn out of the e-cigarette 100 and inhaled through mouthpiece 250.
Since the inner frame 430 is substantially rigid, the vent seal 420 is provided at (inserted around) the top of the airflow tube 432 to ensure a proper seal between the inner frame 430 and the mouthpiece exit hole 280. The vent seal 420 is made of a suitably deformable and resilient material such as silicone. Lastly, the shell 410 provides the external surface of the upper portion 220 of the cartomizer 200, including the mouthpiece 250, and also the lip or flange 240. The shell 410, like the end cap 480, is formed of a substantially rigid material, such as polypropylene. The lower section 412 of the shell 410 (i.e. below the lip 240) sits inside the end cap 480 when the cartomizer 200 has been assembled. The shell 410 is provided with a latch tab 413 on each side to engage with hole 261 on each side of the end cap 480, thereby retaining the cartomizer 200 in its assembled condition.
The airflow passage through the cartomizer 200 enters a central hole in the cap 480 (not visible in
The reservoir 270 of e-liquid is contained in the space between this airflow passage and the outer surface of the cartomizer 200. Thus shell 410 provides the outer walls (and top) of the housing for the reservoir 270, while the lower section 436 of the inner frame 430 in conjunction with the base portion 462 of the primary seal 460 and end cap 480 provide the bottom or floor of the housing for the reservoir 270 of e-liquid. The inner walls of this housing are provided by the atomizing chamber 465 of the primary seal 460, in cooperation with the middle section 434 of the inner frame 430, and also the airflow tube 432 of the inner frame 430 and the vent seal 420. In other words, the e-liquid is stored in the reservoir space between the outer walls and the inner walls. However, the e-liquid should not penetrate inside the inner walls, into the airflow passage, except via wick 440, otherwise there is a risk that liquid would leak out of the mouthpiece hole 280.
The capacity of this space is typically of the order of 2 ml in accordance with some embodiments, although it will be appreciated that this capacity will vary according to the particular features of any given design. Note that unlike for some e-cigarettes, the e-liquid reservoir 270 is not provided with any absorbent material (such as cotton, sponge, foam, etc.) for holding the e-liquid. Rather, the reservoir chamber only contains the liquid, so that the liquid can move freely around the reservoir 270. This has certain advantages, such as generally supporting a larger capacity, and also making the filling procedure less complex. One potential disadvantage with having a free liquid in the reservoir 270 (i.e. not holding the liquid in a sponge or other absorbent structure) is that the liquid can flow more easily, and hence might be more likely to leak in an undesirable manner from the reservoir 270 into the airflow passage. However, such leakage is generally prevented by the vent seal 420 and the primary seal 460.
As visible in
Also visible in
Referring now to
There are also two much smaller holes 587A, 587B formed in the rectangular indentation 584 of the lower portion of the cartomizer plug 460, one on either side of the central hole 583. The contact wires 552A and 552B extend downwards from the heater 450 and pass respectively through these two holes, 587A, 587B, in order to exit the vaporizing chamber 465.
A slit 590A, 590B is formed in each of the front and back walls of the rectangular indentation 584. After extending through the two holes 587A, 587B, each contact wire from the heater 450 is bent flat onto the underside of the cartomizer plug 460, and then leaves the rectangular indentation via the respective slits 590A, 590B. Thus contact wire 552A passes out of the atomizing chamber 465 through hole 587A, and then exits the rectangular indentation 584 via slot 590A; likewise, contact wire 552B passes out of the atomizing chamber 465 through hole 587B, and then exits the rectangular indentation 584 via slot 590B. The remaining portion of each wire 552A, 552B is then bent upwards towards the atomizing chamber 465 in order to sit within a respective groove 597 in the cartomizer plug 460 (see
As noted above, the middle section 434 of the inner frame 430 complements and completes the atomizing chamber 465 of the cartomizer plug 460. In particular, the middle section 434 provides two opposing side walls 668 and a top wall or roof 660. The latter closes the top of the atomizing chamber 465, except in respect of the air tube 432 which extends up from the atomizing chamber 465 to the exit hole 280 of the mouthpiece 250.
Each of the opposing side walls 668 includes a slot 669A, 669B which extends upwards (parallel to the y axis) from the bottom of the side wall 668 to the closed end of the respective slot 669A, 669B. Accordingly, as the base section 436 of the inner frame 430 is lowered down past the atomizing chamber 465, the portions of the wick 440 that extend out from each side of the atomizing chamber 465 pass through these slots 669A, 669B (in addition to slots 671A, 671B). This therefore allows the side walls 668 of the inner frame 430 to overlap the side walls 568 of the cartomizer plug 460. Further downward movement of the inner frame 430 is prevented once the closed end of slots 669A, 669B contacts the wick 440, which coincides with the base section 436 of the inner frame 430 being received into the lower portion 462 of the cartomizer plug 460. At this stage, the combination of cartomizer plug 460, heater/wick assembly 500, and inner frame 430, as shown in
As previously described, the rectangular indentation 584 is provided with a pair of holes 587, located on either side of the central hole 583. Each hole 587 allows egress of a respective contact wire 552A, 552B from the vaporizer chamber 465. The contact wires 552A, 552B are bent flat against the floor of the rectangular indentation 584, and then exit the rectangular indentation 584 via respective slots 590A, 590B in the front and back walls of the rectangular indentation 584n. The final portion of each heater contact wire 552A, 552B, is then bent upwards, back towards the top of the cartomizer 200 and mouthpiece 250, and located in a corresponding groove or channel 597 formed in the cartomizer plug 460. In addition, the base portion 412 of the shell 410 also includes a slot 415 on each of the front and back faces to accommodate a respective heater contact wire 552A, 552B.
In accordance with some embodiments, the PCB 470 does not contain any active components, but rather provides two large contact pads 810A, 810B on either side of the central hole 471. These contact pads are visible in
The opposing pairs of contact pads on either side of the PCB 470 are connected by respective sets of one or more vias 820A, 820B. In other words, vias 820A provide a conductive path between one contact pad on the lower face of the PCB 470 and a corresponding contact pad on the upper face of the PCB 470, and vias 820B provide a conductive path between the other contact pad on the lower face of the PCB 470 and its corresponding contact pad on the upper face of the PCB 470. Accordingly, when the control unit 300 is connected to the cartomizer 200, pins from the control unit 300 touch the contact pads on the lower side of the PCB 470, and electrical current flows to/from the heater 450 through the respective vias 820A, 820B, contact pads on the upper side of the PCB 470, and respective heater contact wires 552A, 552B.
As previously discussed, the end cap 480 includes three holes, a central hole 214 and two holes 212A, 212B located on either side of this central hole 214. The fitting of the end cap 480 aligns the central hole 214 of the end cap with the central hole 471 in the PCB 470 and with the central hole 583 in the primary seal 460 in order to provide the main airflow channel into the cartomizer 200. The two side holes 212A, 212B allow pins from the control unit 300, acting as positive and negative terminals, to pass through the end cap 480 and make contact with respective contact pads 810A, 810B on the lower side of the PCB 470, thereby enabling the battery 350 in the control unit 300 to supply power to the heater 450.
In accordance with some embodiments, the primary seal 460, which as noted above is made of a resilient deformable material such as silicone, is held in a compressed state between the inner frame 430 and the end cap 480. In other words, the end cap 480 is pushed onto the cartomizer 200 and compresses the primary seal 460 slightly before the latch components 413 and 261 engage with one another. Consequently, the primary seal 460 remains in this slightly compressed state after the end cap 480 and shell 410 are latched together. One advantage of this compression is that the end cap 480 acts to push the PCB 470 onto the heater contact wires 552A, 550B, thereby helping to ensure a good electrical connection without the use of solder.
At the bottom of the cavity formed by the upper portion of control unit walls 315 (but otherwise at the top of the main body of the control unit 300) is a battery seal 910 (see also
As shown in
Also shown in
The battery seal 910, which as noted above is made of a resilient deformable material such as silicone, is held in a compressed state between the cartomizer 200 and the control unit 300. In other words, inserting the cartomizer 200 into the cavity formed by walls 315 causes the end cap 480 of the cartomizer 200 to compress the battery seal 910 slightly before the spring clips 931A, 931B of the control unit 300 engage with the corresponding holes 260A, 260B in the lower portion 210 of the cartomizer 200. Consequently, the battery seal 910 remains in this slightly compressed state after the cartomizer 200 and the control unit 300 are latched together, which helps to provide protection against any leakage of e-liquid, as discussed above.
The airflow enters through a gap at the sides of the e-cigarette 100, in between the top of the walls 315 of the control unit 300, and the flange or rim 240 of the cartomizer shell 410. The airflow then passes down a slight spacing between the inside of the walls 315 and the outside of the lower portion 210 of the cartomizer 200, past the spring clips 931, and hence into perimeter groove 921 (as shown in
After travelling an angle of approximately 90 degrees around the perimeter groove 921, the airflow passes into the central groove 922, from where it travels to and through the central hole 583 of the end cap 480 and hence into the central air passage of the cartomizer 200. Note that
There are various benefits associated with the overall airflow path such as shown in
On the other hand, it is generally desirable to reduce or avoid an airflow past electronics components, for example, because such electronics components tend to become warm with use, and may potentially shed volatiles. It will be appreciated that the airflow path shown in
Furthermore, in many existing e-cigarettes, the overall air path is not tightly controlled. For example, air may leak into the air path at joins between various components (such as between the cartomizer 200 and control unit 300), rather than just at the dedicated air inlet(s). This leakage (as well as various other manufacturing variations) may result in significant variation in the draw resistance of the device 100, where the draw resistance in effect represents the pressure difference needed to produce a given air flow through the device 100. This variation in draw resistance can prevent a consistent user experience and can also effect the operation of the device 100. For example, if the draw resistance is high, it is likely that the flow of air through the device 100 may be reduced, which in turn reduces the amount of air cooling experienced by the heater 450.
Accordingly, the approach described herein provides an e-cigarette device including: an atomizer for vaporizing a liquid; an air passage through the atomizer, the air passage exiting the e-cigarette at a mouthpiece; at least one air inlet joined by a channel to the air passage through the vaporizer; and at least one resilient seal which acts to prevent air from the air inlet travelling to the air passage except through the channel.
For example, in the implementation described above, the air flow entering the central air passage through the vaporizer must first travel along groove 922. This groove 922, in conjunction with the bottom of the end cap 480 that in effect provides a top surface or closure for the groove 922, defines the airflow channel through the control unit 300 into the cartomizer 200.
In such a device, air from the air inlet must necessarily travel through the channel to reach the air passage (because the seal prevents other routes). Accordingly, the channel provides a point of control for the draw resistance—especially if the channel provides the majority of the draw resistance for the air path through the whole device 100. In particular, as long as the draw resistance for the channel (which is determined largely by the size of the channel) is reasonably constant between devices (and between different usages of the same device), then the draw resistance for the device as a whole will likewise be reasonably constant.
In some implementations, the e-cigarette 100 may further comprise a facility to alter the predetermined draw resistance for the e-cigarette 100. This facility may allow a user to set the predetermined draw resistance for the e-cigarette 100 to one of a limited number of discrete values according to individual preference, etc. For example, for the e-cigarette 100 described herein, there may be two successive latch positions between the cartomizer 200 and the control unit 300, which result in a lower or greater compression of the battery seal 910. The lower compression will generally allow groove 922 to expand slightly, and hence provide a lower draw resistance than the latch position which produces the higher compression of the battery seal 910. Another way of implementing this facility would be to provide some baffle that can be moved into the channel or groove 922 to partly obstruct the airflow by a desired amount.
The seal 910 may be formed of a resilient material, such as silicone, and the channel is formed at least in part by the seal material itself. For example, in some embodiments, the channel is defined by a resilient material compressed against a surface of a rigid material, such as the battery seal 910 pressing against the end cap 480, and the surface of the rigid material may include a hole, such as hole 583 in end cap 480, that connects from the channel 922 into the air passage through the atomizer. Note that the channel 922 may in fact comprises a network of multiple (sub)channels as appropriate, according to the particular implementation.
As described above, the device may include a cartomizer 200 and a control unit 300, and the resilient seal is provided as part of the control unit that contacts the exterior of the cartomizer when the cartomizer is joined to the control unit. The resilient material may be held under compression between the cartomizer and the control unit when the cartomizer is joined to the control unit, such as by a latch mechanism. This compression of the resilient material helps to provide an air-tight seal around the edges of the seal 910.
A further consideration is that for some e-cigarettes, there is a risk that the e-liquid may leak 270 into main air passage. In such a situation, the seal 910 helps to ensure that the e-liquid is only able to travel from the air passage into the air channel, thereby helping to prevent the e-liquid coming into contact with the battery 350 and other electrical components. Furthermore, the air channel may be sufficiently narrow to prevent significant flow of e-liquid through the channel, which further helps to constrain any leaked e-liquid.
Although various embodiments have been described in detail herein, this is by way of example only, it will be appreciated that a channel to constrain airflow into a device may be utilized in many different configurations. For example, this approach might be used for a one-piece or three-piece device (rather than a two-piece device, i.e. cartomizer and control unit, as described here). Similarly, this approach could be utilized with electronic vapor provision systems that includes material derived from tobacco plants which is provided in any suitable form (powder, paste, shredded leaf material, etc., i.e. not liquid), and then heated to produce volatiles for inhalation by a user. This approach could also be used with various types of heater for the e-cigarette, various types of airflow configuration, various types of connection between the cartomizer and the control unit (such as screw or bayonet), etc. The skilled person will be aware of various other forms of electronic vapor provision system which might utilize a channel for restricting the airflow as described herein.
Furthermore, it will be appreciated the manner of cartomizer assembly set out above is merely one example, and an assembly process comprising different steps, or a similar steps performed in a different order may also be adopted. For example, with reference to the steps set out in relation to
In conclusion, in order to address various issues and advance the art, this disclosure shows by way of illustration various embodiments in which the claimed invention(s) may be practiced. The advantages and features of the disclosure are of a representative sample of embodiments only, and are not exhaustive and/or exclusive. They are presented only to assist in understanding and to teach the claimed invention(s). It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects of the disclosure are not to be considered limitations on 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 may suitably comprise, consist of, or consist essentially of, various combinations of the disclosed elements, components, features, parts, steps, means, etc other than those specifically described herein. The disclosure may include other inventions not presently claimed, but which may be claimed in future.
The present application is a continuation application of U.S. Ser. No. 16/087,012, filed Sep. 20, 2018, which is a National Phase entry of PCT Application No. PCT/GB2017/050788, filed Mar. 21, 2017, which claims priority from GB Patent Application No. 1605104.7, filed Mar. 24, 2016, each of which is hereby fully incorporated herein by reference.
Number | Date | Country | |
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Parent | 16087012 | Sep 2018 | US |
Child | 18501801 | US |