SMOKING SUBSTITUTE DEVICE

Abstract

Disclosed is a smoking substitute device comprising a body, a heating element projecting from an end of the body, a cap for engagement with the end of the body, the cap defining a cavity for receipt of the heating element when engaged with the body, and a lock configured to selectively prevent disengagement of the cap from the body based on a condition of the heating element.

Claims

1. A smoking substitute device comprising: a body a heating element projecting from an end of the body; a cap for engagement with the end of the body, the cap defining a cavity for receipt of the heating element when engaged with the body; and a lock configured to selectively prevent disengagement of the cap from the body based on a condition of the heating element.

2. A device according to claim 1 wherein the lock is configured to selectively prevent disengagement of the cap from the body based on a temperature of the heating element.

3. A device according to claim 2 wherein the lock is configured to selectively prevent disengagement of the cap from the body based on whether the heating element is active.

4. A device according to any one of the preceding claims wherein the lock is configured to prevent disengagement of the cap from the body.

5. A device according to claim 4 wherein the lock is configured to prevent disengagement of the cap from the body when the heating element is in an active state.

6. A device according to any one of the preceding claims wherein the lock forms part of the cap or the body and, when in a locked state, engages a retaining portion forming the other of the cap or the body.

7. A device according to claim 6 wherein the retaining portion comprises an aperture in which a portion of the lock is received.

8. A device according to claim 6 or 7 wherein the lock comprises at least one of an electro-mechanical device, bimetallic component, shape memory allow wire and expanding wax mechanism.

9. A device according to any one of the preceding claims wherein the cap comprises an outer portion for gripping by a user, and an inner portion at least partly enclosing the heating element, and wherein the cap is configured such that a force to disengage the cap from the body, when in the locked state, is greater than a force to separate the outer portion from the inner portion.

10. A device according to claim 9 wherein the outer portion is connected to the inner portion by a weakened portion.

11. A device according to claim 10 wherein the weakened portion is configured to separate at a force that is less than 80N.

12. A device according to any one of claims 9 to 11 wherein the device comprises a tamper sensor for detecting whether the outer portion has been separated from the inner portion.

13. A device according to claim 12 wherein the tamper sensor comprises a hall sensor forming part of the body or the inner portion of the cap, and a magnet disposed on the outer portion.

14. A device according to any one of claims 9 to 13 wherein the lock forms part of the body or inner portion and engages the other of the body or inner portion when in the locked state.

15. A device according to any one of the preceding claims wherein the lock is configured to provide a retaining force of 80N to 100N.

16. A method of controlling a device according to any one of the preceding claims, the method comprising: measuring a temperature of the heating element; comparing the measured temperature to a predetermined threshold temperature; and controlling the lock to enter a locked state if the measured temperature exceeds the threshold temperature.

Description

SUMMARY OF THE FIGURES

[0105] So that the disclosure may be understood, and so that further aspects and features thereof may be appreciated, embodiments illustrating the principles of the disclosure will now be discussed in further detail with reference to the accompanying figures, in which:

[0106] FIG. 1 is a schematic of a smoking substitute system;

[0107] FIG. 2A is a front view of a first embodiment of a smoking substitute system with the consumable engaged with the device;

[0108] FIG. 2B is a front view of the first embodiment of the smoking substitute system with the consumable disengaged from the device;

[0109] FIG. 2C is a section view of the consumable of the first embodiment of the smoking substitute system;

[0110] FIG. 2D is a detailed view of an end of the device of the first embodiment of the smoking substitute system;

[0111] FIG. 2E is a section view of the first embodiment of the substitute smoking system;

[0112] FIG. 3A is a schematic section view of a second embodiment of the substitute smoking system;

[0113] FIG. 3B is a further schematic section view of the second embodiment;

[0114] FIG. 4A is a schematic section view of an embodiment of a lock of a substitute smoking system in an unlocked state; and

[0115] FIG. 4B is a schematic section view of the lock of FIG. 4A in a locked state.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0116] Aspects and embodiments of the present disclosure will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art. All documents mentioned in this text are incorporated herein by reference.

[0117] FIG. 1 is a schematic providing a general overview of a smoking substitute system 100. The system 100 includes a substitute smoking device 101 and an aerosol-forming article in the form of a consumable 102, which comprises an aerosol former 103. The system is configured to vaporize the aerosol former by heating the aerosol former 103 (so as to form a vapor/aerosol for inhalation by a user).

[0118] The system 100 comprises a heater 104, which forms part of the device 101 and is configured to heat the aerosol former 103 when the consumable 102 is engaged with the device 101. Heat from the heater 104 vaporizes the aerosol former 103 to produce a vapor. The vapor subsequently condenses to form an aerosol, which is ultimately inhaled by the user.

[0119] The system further comprises a power source 105 that forms part of the device 101. In other embodiments the power source 105 may be external to (but connectable to) the device 101. The power source 105 is electrically connected to the heater 104 such that it is able to supply power to the heater 104 (i.e., for the purpose of heating the aerosol former 103). Thus, control of the electrical connection of the power source 105 to the heater 104 provides control of the state of the heater 104 (e.g., between an active state and an inactive state). The power source 105 may be a power store, for example a battery or rechargeable battery (e.g., a lithium-ion battery).

[0120] The system 100 further comprises an I/O module comprising a connector 106 (e.g., in the form of a USB port, Micro USB port, USB-C port, etc.). The connector 106 is configured for connection to an external source of electrical power, e.g., a mains electrical supply outlet. The connector 106 may be used in substitution for the power source 105. That is the connector 106 may be electrically connectable to the heater 104 so as to supply electricity to the heater 104. In such embodiments, the device may not include a power source, and the power source of the system may instead comprise the connector 106 and an external source of electrical power (to which the connector 106 provides electrical connection).

[0121] In some embodiments, the connector 106 may be used to charge and recharge the power source 105 where the power source 105 includes a rechargeable battery.

[0122] The system 100 also comprises a user interface (UI) 107. Although not shown, the UI 107 may include input means to receive commands from a user. The input means of the UI 107 allows the user to control at least one aspect of the operation of the system 100. The input means may, for example, be in the form of a button, touchscreen, switch, microphone, etc.

[0123] The UI 107 also comprises output means to convey information to the user. The output means may, for example, comprise lights (e.g., LEDs), a display screen, speaker, vibration generator, etc.

[0124] The system 100 further comprises a controller 108 that is configured to control at least one function of the device 101. In the illustrated embodiment, the controller 108 is a component of the device 101, but in other embodiments may be separate from (but connectable to) the device 101. The controller 108 is configured to control the operation of the heater 104 and, for example, may be configured to control the voltage applied from the power source 105 to the heater 104. The controller 108 may be configured to toggle the supply of power to the heater 104 between an on state, in which the full output voltage of the power source 105 is applied to the heater 104, and an off state, in which the no voltage is applied to the heater 104.

[0125] Although not shown, the system 100 may also comprise a voltage regulator to regulate the output voltage from the power source 105 to form a regulated voltage. The regulated voltage may then be applied to the heater 104.

[0126] In addition to being connected to the heater 104, the controller 108 is operatively connected to the UI 107. Thus, the controller 108 may receive an input signal from the input means of the UI 107. Similarly, the controller 108 may transmit output signals to the UI 107. In response, the output means of the UI 107 may convey information, based on the output signals, to a user. The controller 108 also comprises a memory 109, which is a non-volatile memory. The memory 109 includes instructions, which, when implemented, cause the controller to perform certain tasks or steps of a method.

[0127] FIGS. 2A and 2B illustrate a heated-tobacco (HT) smoking substitute system 200. The system 200 is an example of the system 100 described in relation to FIG. 1. System 200 includes an HT device 201 and an HT consumable 202. The description of FIG. 1 above is applicable to the system 200 of FIGS. 2A and 2B, and will thus not be repeated.

[0128] The device 201 and the consumable 202 are configured such that the consumable 202 can be engaged with the device 201. FIG. 2A shows the device 201 and the consumable 202 in an engaged state, whilst FIG. 2B shows the device 201 and the consumable 202 in a disengaged state.

[0129] The device 201 comprises a body 209 and cap 210. In use the cap 210 is engaged at an end of the body 209.

[0130] The device 201 comprises an output means (forming part of the UI of the device 201) in the form of a plurality of light-emitting diodes (LEDs) 211 arranged linearly along the longitudinal axis of the device 201 and on an outer surface of the body 209 of the device 201. A button 212 is also arranged on an outer surface of the body 209 of the device 201 and is axially spaced (i.e., along the longitudinal axis) from the plurality of LEDs 211.

[0131] FIG. 2C show a detailed section view of the consumable of 202 of the system 200. The consumable 202 generally resembles a cigarette. In that respect, the consumable 202 has a generally cylindrical form with a diameter of 7 mm and an axial length of 70 mm. The consumable 202 comprises an aerosol forming substrate 213, a terminal filter element 214, an upstream filter element 215 and a spacer element 216. In other embodiments, the consumable may further comprise a cooling element. A cooling element may exchange heat with vapor that is formed by the aerosol-forming substrate 213 in order to cool the vapor so as to facilitate condensation of the vapor.

[0132] The aerosol-forming substrate 213 is substantially cylindrical and is located at an upstream end 217 of the consumable 202, and comprises the aerosol former of the system 200. In that respect, the aerosol forming substrate 213 is configured to be heated by the device 201 to release a vapor. The released vapor is subsequently entrained in an airflow flowing through the aerosol-forming substrate 213. The airflow is produced by the action of the user drawing on a downstream 218 (i.e., terminal or mouth) end of the consumable 202.

[0133] In the present embodiment, the aerosol forming substrate 213 comprises tobacco material that may, for example, include any suitable parts of the tobacco plant (e.g., leaves, stems, roots, bark, seeds and flowers). The tobacco may comprise one or more of leaf tobacco, stem tobacco, tobacco powder, tobacco dust, tobacco derivatives, expanded tobacco, homogenized tobacco, shredded tobacco, extruded tobacco, cut rag tobacco and/or reconstituted tobacco (e.g., slurry recon or paper recon). For example, the aerosol-forming substrate 213 may comprise a gathered sheet of homogenized (e.g., paper/slurry recon) tobacco or gathered shreds/strips formed from such a sheet.

[0134] In order to generate an aerosol, the aerosol forming substrate 213 comprises at least one volatile compound that is intended to be vaporized/aerosolized and that may provide the user with a recreational and/or medicinal effect when inhaled. The aerosol-forming substrate 213 may further comprise one or more additives. For example, such additives may be in the form of humectants (e.g., propylene glycol and/or vegetable glycerin), flavorants, fillers, aqueous/non-aqueous solvents and/or binders.

[0135] The terminal filter element 214 is also substantially cylindrical, and is located downstream of the aerosol forming substrate 213 at the downstream end 218 of the consumable 202. The terminal filter element 214 is in the form of a hollow bore filter element having a bore 219 (e.g., for airflow) formed therethrough. The diameter of the bore 219 is 2 mm. The terminal filter element 214 is formed of a porous (e.g., monoacetate) filter material. As set forth above, the downstream end 218 of the consumable 202 (i.e., where the terminal filter 214 is located) forms a mouthpiece portion of the consumable 202 upon which the user draws. Airflow is drawn from the upstream end 217, thorough the components of the consumable 202, and out of the downstream end 218. The airflow is driven by the user drawing on the downstream end 218 (i.e., the mouthpiece portion) of the consumable 202.

[0136] The upstream filter element 215 is located axially adjacent to the aerosol-forming substrate 213, between the aerosol-forming substrate 213 and the terminal filter element 214. Like the terminal filter 214, the upstream filter element 215 is in the form of a hollow bore filter element, such that it has a bore 220 extending axially therethrough. In this way, the upstream filter 215 may act as an airflow restrictor. The upstream filter element 215 is formed of a porous (e.g., monoacetate) filter material. The bore 220 of the upstream filter element 215 has a larger diameter (3 mm) than the terminal filter element 214.

[0137] The spacer 216 is in the form of a cardboard tube, which defines a cavity or chamber between the upstream filter element 215 and the terminal filter element 214. The spacer 216 acts to allow both cooling and mixing of the vapor/aerosol from the aerosol-forming substrate 213. The spacer has an external diameter of 7 mm and an axial length of 14 mm.

[0138] Although not apparent from the figure, the aerosol-forming substrate 213, upstream filter 215 and spacer 216 are circumscribed by a paper wrapping layer. The terminal filter 214 is circumscribed by a tipping layer that also circumscribes a portion of the paper wrapping layer (so as to connect the terminal filter 214 to the remaining components of the consumable 202). The upstream filter 215 and terminal filter 214 are circumscribed by further wrapping layers in the form of plug wraps.

[0139] Returning now to the device 201, FIG. 2D illustrates a detailed view of the end of the device 201 that is configured to engage with the consumable 202. The cap 210 of the device 201 includes an opening 221 to an internal cavity 222 (more apparent from FIG. 2D) defined by the cap 210. The opening 221 and the cavity 222 are formed so as to receive at least a portion of the consumable 202. During engagement of the consumable 202 with the device 201, a portion of the consumable 202 is received through the opening 221 and into the cavity 222. After engagement (see FIG. 2B), the downstream end 218 of the consumable 202 protrudes from the opening 221 and thus also protrudes from the device 201. The opening 221 includes laterally disposed notches 226. When a consumable 202 is received in the opening 221, these notches 226 remain open and could, for example, be used for retaining a cover in order to cover the end of the device 201.

[0140] Although not apparent from the figures, the cap 210 is releasably engaged with the device 201 via a snap engagement mechanism. Thus, the cap 210 is removable, for example, for cleaning the device 201.

[0141] FIG. 2E shows a cross section through a central longitudinal plane through the device 201. The device 201 is shown with the consumable 202 engaged therewith.

[0142] The device 201 comprises a heater 204 having a heating element 223. The heater 204 forms part of the body 209 of the device 201 and is rigidly mounted to the body 209. In the illustrated embodiment, the heater 204 is a rod heater with a heating element 223 having a circular transverse profile. In other embodiments the heating element may be in the form of a blade heater (e.g., heating element with a rectangular transverse profile) or a tube heater (e.g., heating element with a tubular form).

[0143] The heating element 223 of the heater 204 projects from an internal base of the cavity 222 along a longitudinal axis towards the opening 221. As is apparent from the figure, the length (i.e., along the longitudinal axis) of the heating element is less than a depth of the cavity 222. In this way, the heating element 223 does not protrude from or extend beyond the opening 221.

[0144] When the consumable 202 is received in the cavity 222 (as is shown in FIG. 2E), the heating element 223 penetrates the aerosol-forming substrate 213 of the consumable 202. In particular, the heating element 223 extends for nearly the entire axial length of the aerosol-forming substrate 213 when inserted therein. Thus, when the heater 204 is activated, heat is transferred radially from an outer circumferential surface the heating element 223 to the aerosol-forming substrate 213.

[0145] The device 201 further comprises an electronics cavity 224. A power source, in the form of a rechargeable battery 205 (a lithium-ion battery), is located in electronics cavity 224.

[0146] The device 201 includes a connector (i.e., forming part of an IO module of the device 201) in the form of a USB port 206. The connector may alternatively be, for example, a micro-USB port or a USB-C port for examples. The USB port 206 may be used to recharge the rechargeable battery 205.

[0147] The device 201 includes a controller (not shown) located in the electronics cavity 224. The controller comprises a microcontroller mounted on a printed circuit board (PCB). The USB port 206 is also connected to the controller 208 (i.e., connected to the PCB and microcontroller).

[0148] The controller 208 is configured to control at least one function of the device 202. For example, the controller 208 is configured to control the operation of the heater 204. Such control of the operation of the heater 204 may be accomplished by the controller toggling the electrical connection of the rechargeable battery 205 to the heater 204. For example, the controller 208 is configured to control the heater 204 in response to a user depressing the button 212. Depressing the button 212 may cause the controller to allow a voltage (from the rechargeable battery 205) to be applied to the heater 204 (so as to cause the heating element 223 to be heated).

[0149] The controller is also configured to control the LEDs 211 in response to (e.g., a detected) a condition of the device 201 or the consumable 202. For example, the controller may control the LEDs to indicate whether the device 201 is in an on state or an off state (e.g., one or more of the LEDs may be illuminated by the controller when the device is in an on state).

[0150] The device 201 comprises a further input means (i.e., in addition to the button 212) in the form of a puff sensor 225. The puff sensor 225 is configured to detect a user drawing (i.e., inhaling) at the downstream end 218 of the consumable 202. The puff sensor 225 may, for example, be in the form of a pressure sensor, flowmeter or a microphone. The puff sensor 225 is operatively connected to the controller 208 in the electronics cavity 224, such that a signal from the puff sensor 225, indicative of a puff state (i.e., drawing or not drawing), forms an input to the controller 208 (and can thus be responded to by the controller 208).

[0151] FIGS. 3A and 3B provide a further embodiment of the system 300, which illustrates the interaction between the cap 310 and the body 309 (and the heating element 323) of the device 301. It should be appreciated that the features described with respect to this embodiment, could equally form part of the previously described embodiment (as shown in FIG. 2A to 2E).

[0152] The cap 310 is generally formed of an outer portion 327 and an inner portion 328 that are connected to one another (at respective upper ends) by a weakened portion 329 of the cap 310, which is in the form of a thinner portion of the wall of the cap 310.

[0153] The outer portion 327 extends about the inner portion 328 and, when engaged with the body 309, an outer surface of the outer portion 327 defines an outer surface of the device 301. In other words, it is the outer portion 327 of the cap 310 that is gripped by a user in order to disengage the cap 310 from the body 309. The outer portion 327 comprises ramped protrusions 330. These are located at a lower end of the outer portion 327, that is proximate the body 309 when the cap 310 is engaged therewith. The ramped protrusions 330 are received in, and engaged with, corresponding (and complementary) ramped recesses 331. In this way, the cap 310 is releasably snap-engaged with the body 309.

[0154] The inner portion 328 is tubular and extends centrally and downwardly (at least in the orientation illustrated), from the upper opening 321 in the cap 310. Thus, the inner portion 328 defines a cylindrical cavity 322 into which a consumable 302 may be received (i.e., through the opening 321). A lower end of the inner portion 328 comprises an aperture, through which the heating element 323 projects into the cavity 322.

[0155] The inner portion 328 also comprises a retaining portion 333 that projects downwardly from its lower end and that is received in a recess formed in the body 309. As will be described further below with reference to FIGS. 4A and 4B, the retaining portion 309 engages with a lock 334 that forms part of the body 309. The lock 334 is moveable, in response to a control signal from the controller 308, between a locked state and an unlocked state. In the locked state, the lock 334 engages the retaining portion 333 and prevents the cap 310 from being disengaged from the body 309. In the unlocked state, the lock 334 is disengaged from the retaining portion 333, such that the cap 310 can be disengaged from the body 309 (with only minor resistance being provided by the engagement of the ramped protrusions 330 and the ramped recesses 331).

[0156] The controller 308 is configured to receive a signal indicative of a temperature of the heating element 323 (e.g., via a temperature sensor) and control the lock 334 in response to the temperature. In particular, the controller 308 is configured to compare the measured temperature of the heating element 323 to a predetermined threshold temperature. If the measured temperature exceeds the predetermined threshold temperature, then the controller 308 causes the lock 334 to enter the locked state. This may prevent a user from removing the cap 310, so as to expose the hot heating element 323, which could potentially cause injury to the user. When the measured temperature is less than the predetermined threshold temperature, the controller is configured to cause the lock 334 to enter the unlocked state, so as to allow a user to disengage the cap 310 from the body 309.

[0157] The device 301 comprises means for detecting when the cap 310 is removed from the body 309. This is in the form of a hall sensor 336 in the body 309 and a magnet 335 mounted to an inwardly extending projection of the outer portion 327 so as to be adjacent to the all sensor 336 when the cap 310 is engaged with the body 309. When the cap 310 is disengaged from the body 309, the hall sensor 336 no longer detects the presence of the magnet 335. The hall sensor 336 is operatively connected to the controller 308, which is configured to determine that, when the hall sensor 336 provides a signal indicative of the presence of the magnet 335, the cap 310 is engaged with the body 309 and, when the hall sensor 336 provides a signal indicative of the magnet 335 not being present (or provides not signal), the cap 310 is disengaged from the body 309. The controller 308 is further configured to prevent the supply of power to the heating element 323 when the cap 310 is disengaged from the body 309.

[0158] As noted above, the inner portion 328 is connected to the outer portion 327 by way of a weakened portion 329 of the cap 310. The weakened portion 329 is specifically configured so as to separate (i.e., break) under a force, imparted by pulling on the cap 310, that is less than the retaining force provided by the lock 334. This means that, if a user attempts (with significant force) to disengage the cap 310 while the lock 334 is in the locked state, the outer portion 327 will separate from the inner portion 328 before the lock 334 releases the retaining portion 333 (e.g., due to lock being damaged).

[0159] FIG. 3B illustrates the cap 310 in this separated state. As is apparent from this figure, when the outer portion 327 separates from the inner portion 328, the inner portion 328 remains engaged with the body 309 by way of the lock 334. In this way, the inner portion 328, in which the heating element 323 projects, provides a barrier to the heating element 323 even though the outer portion 327 has been removed. This ensures that even if a user attempts to remove the cap 310 (i.e., with significant force) when the heating element 323 is above the predetermined threshold temperature, they are still protected from being burnt by the heating element 323. Thus, the provision of the weakened portion 329 may improve the safety of the device 301.

[0160] The safety of the device 301 may further be improved by the positioning of the hall sensor 336 and the corresponding magnet 335. As previously mentioned, the magnet 335 is mounted to the outer portion 327 rather than the inner portion 328. Thus, when the outer portion 327 is separated from the outer portion 327, the magnet 335 moves away from the hall sensor 336 (positioned on the body 309). As a consequence of this, the hall sensor 336 no longer detects the presence of the magnet 335, and in response the controller 308 prevent further supply of power to the heating element 323 (in this respect, the hall sensor 336 may be considered a tamper sensor). Thus, separation of the outer portion 327 from the inner portion 328 leads to the power supply to the heating element 323 being stopped (and thus subsequent cooling-down of the heating element 323).

[0161] FIGS. 4A and 4B illustrate an exemplary lock 434, which could form part of any of the embodiments previously described. The lock 434 is in the form of a solenoid lock and is disposed in a recess 437 of the body 409 (although it could equally form part the cap 410). The cap 410 comprises a retaining portion 433 that projects downwardly from a lower end of the cap 410 and into the recess 437. The retaining portion 433 comprises a laterally extending aperture 438 formed therein, which aligns with the lock 434 when the retaining portion 433 is received in the recess 437. The lock 434 comprises a pin 439 that is moveable (e.g., in response to a signal from a controller) between a retracted state (shown in FIG. 4A) and an extended state (shown in FIG. 4B).

[0162] In the retracted state, the pin 439 is retracted away from the retaining portion 433 so as to allow movement of the retraining portion 433 into and out of the recess 437. This is representative of the lock 434 being in an unlocked state. In the extended state, the pin 439 extends laterally across the recess 437 and through the aperture 438 formed in the retaining portion 433. In this state, the retaining portion 433 is prevented from being moved out of the recess 437 by way of engagement of the pin 439 with the sides of the aperture 438. The retracted state is representative of the lock 434 being in a locked state.

[0163] The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for obtaining the disclosed results, as appropriate, may, separately, or in any combination of such features, be utilized for realizing the disclosure in diverse forms thereof.

[0164] While the disclosure has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the disclosure set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the disclosure.

[0165] For the avoidance of any doubt, any theoretical explanations provided herein are provided for the purposes of improving the understanding of a reader. The inventors do not wish to be bound by any of these theoretical explanations.

[0166] Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0167] Throughout this specification, including the claims which follow, unless the context requires otherwise, the words “have”, “comprise”, and “include”, and variations such as “having”, “comprises”, “comprising”, and “including” will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

[0168] It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by the use of the antecedent “about,” it will be understood that the particular value forms another embodiment. The term “about” in relation to a numerical value is optional and means, for example, +/−10%.

[0169] The words “preferred” and “preferably” are used herein refer to embodiments of the disclosure that may provide certain benefits under some circumstances. It is to be appreciated, however, that other embodiments may also be preferred under the same or different circumstances. The recitation of one or more preferred embodiments therefore does not mean or imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the disclosure, or from the scope of the claims.