Patent Description:
Electronic vaping devices (or e-vaping devices) are used to vaporize a liquid material into a vapor in order for a user (an adult electronic vaper or adult vaper) to inhale the vapor. E-vaping devices typically include a heater which vaporizes liquid material to produce a vapor. An e-vaping device may include several e-vaping elements including a power source, a cartridge or e-vaping tank including the heater and a reservoir capable of holding the liquid material.

A tobacco-based smoking article typically produces a vapor known to create a familiar sensory experience for adult smokers, including a low to moderate harshness response in the throat and a perceived warmth in the chest. The preferred levels of harshness in the throat and perceived warmth in the chest may differ amongst adult smokers. Users of e-vaping devices (adult vapers) typically prefer vaping a device that does not generate too much harshness but that is sufficient to produce a pleasant or familiar experience.

Liquid formulations for e-vaping devices comprising nicotine and one or more aerosol formers, such as propylene glycol, are widely available.

<CIT> discloses a liquid formulation for an e-vaping device with a health orientation namely preventing and curing decayed teeth. The formulation comprises tobacco leaf extract, <NUM>-<NUM>% w/v propylene glycol, <NUM>-<NUM>% w/v water, tobacco flavor, stabilizer, thickener, xylitol, L-arabinose and sodium fluoride solution.

<CIT> discloses a health-care electronic cigarette liquid for medical use, which comprises: tobacco leaf extract, <NUM>-<NUM>% w/v propylene glycol, <NUM>-<NUM>% w/v pure water, tobacco flavor, stabilizer, thickener and a medicament.

The invention is defined in the appended independent claims, to which reference should now be made. Optional features of the invention are defined in dependent claims. Aspects, embodiments or examples falling outside the scope of the appended independent claims are not part of the invention, and are merely included for illustrative or explanatory purposes. According to the present invention there is provided a liquid formulation for an e-vaping device, the liquid formulation comprising: a vapor former including propylene glycol, water and substantially no amount of glycerol, wherein a concentration of propylene glycol in the vapor former is <NUM> percent by weight and a concentration of water in the vapor former is <NUM> percent by weight; nicotine, wherein a concentration of nicotine in the liquid formulation is equal to or lower than <NUM> percent by weight; and one or more acids, wherein the liquid formulation is configured to form a vapor having a particulate phase and a gas phase when heated in the e-vaping device.

The liquid formulation is configured to form a vapor having a gas phase upon operation of the e-vaping device.

The liquid formulation includes one or more acids. The acid is operative upon the vapor so as to reduce an amount of nicotine content in the gas phase of the vapor.

The vapor former including propylene glycol and substantially no glycerol or glycerin provides nicotine delivery, has a higher wicking rate and capillary efficiency in the cartomizer, evaporates easier, and generates a vapor that is less visible than a vapor formed by a vapor former including both propylene glycol and glycerol/glycerin. The above advantages may be due, among other reasons, to the fact that propylene glycol is substantially less viscous than glycerol and has a lower boiling point than glycerol. In addition, less battery power is required to generate a vapor when the vapor former includes propylene glycol and substantially no glycerol/glycerin. As a result, the performance of the e-vaping device is improved in terms of vapor formation efficiency and battery power usage.

As a result of higher evaporation of the vapor, vapor phase nicotine, which is the concentration of nicotine in the vapor phase of the vapor generated during vaping of the e-vaping device, is substantially increased compared to a lower evaporation rate of the vapor. As a result of the higher vapor phase nicotine, the perception in the chest of a user typically increases. As another result of the higher vapor phase nicotine, a lower nicotine level may be used in the vapor precursor or liquid formulation of the e-vaping device. For example, a nicotine level of substantially <NUM> percent, and nicotine levels that are lower than about <NUM> percent, may be used. For example, nicotine levels of about <NUM> percent, about <NUM> percent and about <NUM> percent may be used.

In addition, as the propylene glycol concentration in the vapor former increases, the visibility of the vapor exhaled by the user decreases. When the vapor former includes propylene glycol and substantially no glycerol, the vapor exhaled by the user is substantially invisible. Accordingly, a vapor precursor or liquid formulation including a vapor former having propylene glycol and substantially no glycerol/glycerin provides the ability for the user to vape without generating a noticeable amount of vapor.

The concentration of acids may be substantially <NUM> percent.

In one embodiment, the liquid formulation may include an acid having a boiling point of at least about <NUM> degrees Celsius and configured to volatilize when heated by a heater in the e-vaping device. The liquid formulation is configured to form a vapor having a particulate phase and a gas phase when heated by the heater in the e-vaping device, the particulate phase containing protonated nicotine and the gas phase containing unprotonated nicotine, and the vapor has a majority amount of the protonated nicotine and a minority amount of the unprotonated nicotine. In one embodiment, the acid is operative upon the vapor so as to reduce the amount of perceived throat harshness by a user in comparison to the vapor being formed upon operation of the e-vaping device without the acid.

In one embodiment, the acid is selected to have a liquid to vapor transfer efficiency of about <NUM> percent or greater and in an amount sufficient to reduce the nicotine gas phase component compared to the nicotine gas phase component of an e-vaping device having a vapor precursor or liquid formulation that does not include the acid. For example, the reduction may be of substantially <NUM> percent or greater.

In one embodiment, the acidic compound that is part of the vapor precursor or liquid formulation may include at least one of pyruvic acid, formic acid, oxalic acid, glycolic acid, acetic acid, isovaleric acid, valeric acid, propionic acid, octanoic acid, lactic acid, sorbic acid, malic acid, tartaric acid, succinic acid, citric acid, benzoic acid, oleic acid, aconitic acid, butyric acid, cinnamic acid, decanoic acid, <NUM>,<NUM>-dimethyl-<NUM>-octenoic acid, <NUM>-glutamic acid, heptanoic acid, hexanoic acid, <NUM>-hexenoic acid, trans-<NUM>-hexenoic acid, isobutyric acid, lauric acid, <NUM>-methylbutyric acid, <NUM>-methylvaleric acid, myristic acid, nonanoic acid, palmitic acid, <NUM>-pentenoic acid, phenylacetic acid, <NUM>-phenylpropionic acid, hydrochloric acid, phosphoric acid and sulfuric acid.

In one embodiment, the acidic compound consists of a mixture of pyruvic acid, lactic acid, benzoic acid and acetic acid.

The liquid formulation includes water. Water can be included in an amount ranging from about <NUM> percent by weight based on the weight of the liquid formulation to about <NUM> percent by weight based on the weight of the liquid formulation. For example, water may be included at about <NUM> percent by weight based on the weight of the liquid formulation.

Features of any of the aspects and embodiments of the present invention described herein may be combined with one or more of the other aspects and embodiments of the present invention.

The above and other features and advantages of example embodiments will become more apparent by describing in detail, example embodiments with reference to the attached drawings. The accompanying drawings are intended to depict example embodiments and should not be interpreted to limit the intended scope of the claims.

Some detailed example embodiments are disclosed herein. However, specific structural and functional details disclosed herein are merely representative for purposes of describing example embodiments. Example embodiments may, however, be embodied in many alternate forms and should not be construed as limited to only the embodiments set forth herein.

Accordingly, while example embodiments are capable of various modifications and alternative forms, embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit example embodiments to the particular forms disclosed, but to the contrary, example embodiments are to cover all modifications, equivalents, and alternatives falling within the scope of example embodiments. Like numbers refer to like elements throughout the description of the figures.

It should be understood that when an element or layer is referred to as being "on," "connected to," "coupled to," or "covering" another element or layer, it may be directly on, connected to, coupled to, or covering the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly connected to," or "directly coupled to" another element or layer, there are no intervening elements or layers present. Like numbers refer to like elements throughout the specification.

It should be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers or sections, these elements, components, regions, layers, or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or section from another region, layer, or section. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of example embodiments.

Spatially relative terms (for example, "beneath," "below," "lower," "above," "upper," and the like) may be used herein for ease of description to describe one element or feature's relationship to another element or feature as illustrated in the figures. It should be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. Thus, the term "below" may encompass both an orientation of above and below.

The terminology used herein is for the purpose of describing various embodiments only and is not intended to be limiting of example embodiments. It will be further understood that the terms "includes," "including," "comprises," and "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof.

Example embodiments are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of example embodiments. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and tolerances, are to be expected. Thus, example embodiments should not be construed as limited to the shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of example embodiments.

When the terms "about" or "substantially" are used in this specification in connection with a numerical value, it is intended that the associated numerical value include a tolerance of ±<NUM> percent around the stated numerical value. Moreover, when reference is made to percentages in this specification, it is intended that those percentages are based on weight, that is, weight percentages. The expression "up to" includes amounts of zero to the expressed upper limit and all values therebetween. When ranges are specified, the range includes all values therebetween such as increments of <NUM> percent.

In one embodiment, an e-vaping device includes a liquid supply reservoir containing a liquid formulation. The liquid formulation is delivered to a heater of the e-vaping device where the liquid formulation is heated and volatilized to form a vapor upon operation of the e-vaping device. In an example embodiment, the liquid formulation includes a mixture of molecular nicotine (unprotonated and uncharged) and an acid, which protonates nearly all of the molecular nicotine in the liquid formulation, so that upon heating of the liquid formulation by a heater in the e-vaping device, a vapor having a majority amount of protonated nicotine and a minority amount of unprotonated nicotine is produced, whereby only a minor portion of all the vaporized nicotine typically remains in the gas phase of the vapor. The fraction of nicotine in the gas phase may contribute to perceptions of throat harshness or other perceived off-tastes. Reducing the proportional level of nicotine in the gas phase may improve the perceived subjective deficits associated with nicotine in the gas phase. For example, a proportion of nicotine in the gas phase of the vaporized nicotine may be substantially <NUM> percent, substantially <NUM> percent or less of the total nicotine delivered.

As used herein, the term "vapor former" describes any suitable known compound or mixture of compounds that, in use, facilitates formation of a vapor and that is substantially resistant to thermal degradation at the operating temperature of the vapor-generating device. Suitable vapor-formers consist of various compositions of polyhydric alcohols such as propylene glycol. In one embodiment, the vapor is propylene glycol.

The liquid formulation may optionally include one or more flavorants in an amount ranging from about <NUM> percent to about <NUM> percent by weight (for example, about <NUM> percent to about <NUM> percent, about <NUM> percent to about <NUM> percent, or about <NUM> percent to about <NUM> percent). The flavorant can be a natural flavorant or an artificial flavorant. In one embodiment, the flavorant is one of tobacco flavor, menthol, wintergreen, peppermint, herb flavors, fruit flavors, nut flavors, liquor flavors, and combinations thereof.

The following examples describe the taste and perception differences between i) formulations that include a mixture of propylene glycol and glycerol, and ii) formulations that include propylene glycol but do not include glycerol. The amount of nicotine in the various formulations may be between about <NUM> percent and about <NUM> percent. For example, nicotine levels of about <NUM> percent, about <NUM> percent, about <NUM> percent, about <NUM> percent, about <NUM> percent and about <NUM> percent may be used. The following examples of e-vaping devices are discussed:
COMPARATIVE EXAMPLE <NUM>: A first comparative liquid formulation solution includes about <NUM> percent propylene glycol (PG), about <NUM> percent glycerol (Gly), about <NUM> percent water and about <NUM> percent nicotine by weight (NBW) with substantially no acid.

COMPARATIVE EXAMPLE <NUM>: A second comparative liquid formulation solution includes about <NUM> percent propylene glycol, about <NUM> percent glycerol, about <NUM> percent water, about <NUM> percent nicotine by weight (NBW) and about <NUM> percent of menthol as a flavorant, with substantially no acid.

EXAMPLE <NUM>: A first example embodiment of a liquid formulation solution includes about <NUM> percent propylene glycol, substantially no glycerol, about <NUM> percent water and about <NUM> percent nicotine by weight (NBW) with substantially no acid.

EXAMPLE <NUM>: A second example embodiment of a liquid formulation solution includes about <NUM> percent propylene glycol, substantially no glycerol, about <NUM> percent water and about <NUM> percent nicotine by weight (NBW) with substantially no acid. The liquid formulation also includes substantially <NUM> percent menthol by weight.

Comparing Examples <NUM> and <NUM> to Examples <NUM> and <NUM>, as described in Table <NUM> below, shows that the removal of glycerol substantially increased the overall enjoyment (overall "liking") of the e-vaping device.

Table <NUM> describes the reaction of a panel of eight users (adult vapers) who performed a taste-test for the examples described above. The users were asked to score the overall enjoyment, or liking, of the e-vaping device, on a scale of <NUM> to <NUM>. The users were asked to rank the "Flavor Liking or Menthol Perception" to provide an evaluation of their liking of the flavorant, and in the case where the flavorant is menthol, of their perception of the menthol in the e-vaping device. The users were also asked to rank the impact of the e-vaping device for each one of the comparative examples and the example embodiments, the strength being perceived in the chest of the user. For example, the strength of the e-vaping device may be the perception of a strong nicotine taste in the chest of the users. The users also ranked the harshness of the e-vaping devices based on the various liquid compositions, the harshness being perceived in one or both of the mouth and the throat of the user. For example, the harshness may be the perception of a burning sensation in one or both of the mouth and the throat of the user during use of the e-vaping device, the burning sensation being due to the combination of propylene glycol and glycerol.

Based on the results described on Table <NUM>, Example Embodiments <NUM> and <NUM> yield greater average scores of <NUM> and <NUM> on a scale of <NUM>-<NUM> compared to Comparative Examples <NUM> and <NUM>, which yield average scores of <NUM> each. Thus, the expert panel of users concluded that e-vaping devices having liquid formulations that include a mixture of propylene glycol, water and nicotine, without including glycerin/glycerol have a more positive perception of the flavor and a better sensation of impact in the chest, harshness in one or both of the mouth and the throat, of the user.

The following experiments also discuss the taste and perception differences among formulations that include a mixture of propylene glycol and glycerol as well as formulations that do not include glycerol. The amount of nicotine in the various formulations is about <NUM> percent, and the amount of water is about <NUM> percent. In the experiments, nicotine measurements per puff of an e-vaping device by a user have been taken with respect to a relative concentration of propylene glycol and glycerol.

The examples of e-vaping devices are discussed below with respect to Table <NUM>:.

Based on the results described in Table <NUM>, and for the same e-vaping conditions, that is, a same battery power output, cartomizer configuration and nicotine and water content in the liquid formulation, the vapor mass and nicotine in the vapor generated per puff (milligrams of nicotine/puff) are different with different propylene glycol to glycerol ratios in the liquid formulation of the e-vaping device. Accordingly, as propylene glycol fraction in the liquid formulation increases, the inhaled vapor produces more strength or impact in the chest of the user, as evidenced by the increasing amount of nicotine per puff. The increasing amount of nicotine per puff is proportional to an increase in the concentration of propylene glycol in the liquid formulation.

This effect may be due, among other reasons, to the fact that propylene glycol is substantially less viscous than glycerol. As a result, liquid formulations with increased propylene glycol typically have a higher wicking rate and capillary efficiency. Propylene glycol also has a lower boiling point than glycerol. As a result, generation of the vapor is easier for liquid formulations that have increased propylene glycol. In addition, less battery power is required to generate a vapor when the vapor former includes propylene glycol and substantially no glycerol because of the easier generation of vapor. As a result of the above and of the increased fluid properties of propylene glycol, the performance of the e-vaping device is improved in terms of vapor formation efficiency and battery power usage when more propylene glycol is provided in the liquid formulation.

In examples, as the propylene glycol concentration in the vapor former increases, the visibility of the exhaled vapor decreases. When the vapor former includes propylene glycol and substantially no glycerol, the vapor exhaled by a user is substantially invisible. Accordingly, a liquid formulation including a vapor former having propylene glycol and substantially no glycerol provides the ability for the user to vape without generating vapor. For example, a liquid formulation having substantially <NUM> percent propylene glycol, substantially <NUM> percent water and substantially no glycerol may provide the above advantages.

According to at least one example, an acid can be added to the vapor precursor, the acid having the effect of reducing the production of gas phase nicotine with typically minimal sensory and operational impact on the e-vaping device.

In another example, the acid is added within an acceptable sensorial amount according to a sensory impact associated with the acid. For example, to some users, acetic acid, when added at certain levels, may impart a "vinegar" sensorial response. Accordingly, in one embodiment, the acetic acid content may be limited to levels below where such sensory impact arises. Other acids can also be used in combination with the acetic (or other) acid in a similar manner so as to establish an acid complex wherein the desired level of acid functionality is achieved (with multiple acids), but with each acid being included at a level below where noticeable or objectionable sensory impact may arise.

According to at least one example, the acid has a boiling point of at least about <NUM> degrees Celsius, and may be included in the liquid formulation in an amount sufficient to adjust the pH of the liquid formulation in the range of about <NUM> to about <NUM>.

In one example, the acid is included in an amount sufficient to reduce the amount of nicotine gas phase component by about <NUM> percent by weight or greater, preferably about <NUM> percent to about <NUM> percent by weight, more preferably, about <NUM> percent by weight or greater, and most preferably about <NUM> percent by weight or greater, of the level of nicotine gas phase component produced without the acid.

In one example, the acid is operative upon the vapor generated from the liquid formulation upon operation of the e-vaping device so as to reduce the amount of perceived throat harshness in comparison to the vapor formed without the acid.

According to at least one example, the acid included in the liquid formulation includes one or more of pyruvic acid, formic acid, oxalic acid, glycolic acid, acetic acid, isovaleric acid, valeric acid, propionic acid, octanoic acid, lactic acid, levulinic acid, sorbic acid, malic acid, tartaric acid, succinic acid, citric acid, benzoic acid, oleic acid, aconitic acid, butyric acid, cinnamic acid, decanoic acid, <NUM>,<NUM>-dimethyl-<NUM>-octenoic acid, <NUM>-glutamic acid, heptanoic acid, hexanoic acid, <NUM>-hexenoic acid, trans-<NUM>-hexenoic acid, isobutyric acid, lauric acid, <NUM>-methylbutyric acid, <NUM>-methylvaleric acid, myristic acid, nonanoic acid, palmitic acid, <NUM>-pentenoic acid, phenylacetic acid, <NUM>-phenylpropionic acid, hydrochloric acid, phosphoric acid, sulfuric acid, and combinations thereof. The acid also may be incorporated in the form of a salt.

<FIG> is a side view of an e-vaping device, according to a first example. In <FIG>, the liquid formulation forms a vapor when vaporized in an e-vaping device <NUM> such as, for example, an e-vaping device, as shown in <FIG>. The e-vaping device <NUM> comprises a replaceable cartridge (or first section) <NUM> and a reusable fixture (or second section) <NUM>, which are coupled together at a threaded joint <NUM> or by other connecting structure such as one or more of a snug-fit, snap-fit, detent, clamp, clasp, or the like.

<FIG> is a cross-sectional view of another example of an e-vaping device. As shown in <FIG>, the first section <NUM> can house a mouth-end insert <NUM>, a capillary vapor generator including a capillary tube <NUM>, a heater <NUM> to heat at least a portion of the capillary tube <NUM>, a liquid supply reservoir <NUM>, and optionally a valve <NUM>. Alternatively, as shown in <FIG>, the first section <NUM> can house a mouth-end insert <NUM>, a heater <NUM>, a flexible, filamentary wick <NUM> and a liquid supply reservoir <NUM> as discussed in further detail below.

The second section <NUM> can house a power supply <NUM> (shown in <FIG>, <FIG>), a control circuitry <NUM>, and optionally a puff sensor <NUM> (shown in <FIG> and <FIG>). The threaded portion <NUM> of the second section <NUM> can be connected to a battery charger, when not connected to the first section <NUM>, to charge the battery or power supply <NUM>.

<FIG> is a cross-sectional view of an e-vaping device according to another example. As shown in <FIG>, the e-vaping device <NUM> can also include a middle section (third section) <NUM>, which can house the liquid supply reservoir <NUM>, the heater <NUM> and the valve <NUM>. The middle section <NUM> can be configured to be fitted with a threaded joint <NUM>' at an upstream end of the first section <NUM> and a threaded joint <NUM> at a downstream end of the second section <NUM>. In this example, the first section <NUM> houses the mouth-end insert <NUM>, while the second section <NUM> houses the power supply <NUM> and the control circuitry <NUM>.

In one example, the first section <NUM>, the second section <NUM> and the optional third section <NUM> include an outer cylindrical housing <NUM> extending in a longitudinal direction along the length of the e-vaping device <NUM>. Moreover, in one example, the middle section <NUM> is disposable and one or both of the first section <NUM> and the second section <NUM> are reusable. The sections <NUM>, <NUM>, <NUM> can be attached by threaded connections or connectors whereby the middle section <NUM> can be replaced when the liquid supply reservoir <NUM> is used up. In another example, the first section <NUM> can also be replaceable so as to avoid the need for cleaning one or both of the capillary tube <NUM> and the heater <NUM>.

In one example, the first section <NUM> and the second section <NUM> may be integrally formed without threaded connections to form a disposable e-vaping device.

As shown in <FIG>, the outer cylindrical housing <NUM> can include a cutout or depression <NUM> which allows a user to manually apply pressure to the liquid supply reservoir <NUM>. In one example, the outer cylindrical housing <NUM> is one or both of flexible and compressible along the length thereof and fully or partially covers the liquid supply reservoir <NUM>. The cutout or depression <NUM> can extend partially about the circumference of the outer cylindrical housing <NUM>. Thus, the outer cylindrical housing <NUM> can be formed of or include a variety of materials including plastics, rubber and combinations thereof. In one example, the outer cylindrical housing <NUM> is formed of or includes silicone. The outer cylindrical housing <NUM> can be any suitable color. The outer cylindrical housing <NUM> can include graphics or other indicia printed thereon. Moreover, the liquid supply reservoir <NUM> is compressible such that when pressure is applied to the liquid supply reservoir, liquid is pumped from the liquid supply reservoir <NUM> to the capillary tube <NUM>. A pressure activated switch <NUM> can be positioned beneath the liquid supply reservoir <NUM>. When pressure is applied to the liquid supply reservoir <NUM> to pump liquid, the switch is also pressed and a heater <NUM> is activated. The heater <NUM> can be a portion of the capillary tube <NUM>. By applying manual pressure to the pressure switch, the power supply <NUM> is activated and an electric current heats the liquid in the capillary tube <NUM> via electrical contacts so as to volatilize the liquid.

In the example illustrated in <FIG>, the liquid supply reservoir <NUM> is a tubular, elongated body formed of or including an elastomeric material so as to be one or both of flexible and compressible when squeezed. In one example, the elastomeric material can be one of silicone, plastic, rubber, latex, and combinations thereof.

In one example, the compressible liquid supply reservoir <NUM> has an outlet <NUM> in fluid communication with a capillary tube <NUM> so that when squeezed, the liquid supply reservoir <NUM> can deliver a volume of liquid material to the capillary tube <NUM>. Contemporaneously to delivering liquid to the capillary, the power supply <NUM> is activated upon the application of the manual pressure on the pressure switch, and the capillary tube <NUM> is heated to form a heated section wherein the liquid material is volatilized. Upon discharge from the heated capillary tube <NUM>, the volatilized material expands, mixes with air and forms a vapor.

In one example, the liquid supply reservoir <NUM> extends longitudinally within the outer cylindrical housing <NUM> of the first section <NUM> (shown in <FIG>) or the middle section <NUM> (shown in <FIG>). Moreover, the liquid supply reservoir <NUM> contains a liquid formulation that is configured to be volatilized when heated and to form a vapor when discharged from the capillary tube <NUM>.

In the examples illustrated in <FIG> and <FIG>, the capillary tube <NUM> includes an inlet end <NUM> in fluid communication with the outlet <NUM> of the liquid supply reservoir <NUM>, and an outlet end <NUM> configured to expel volatilized liquid material from the capillary tube <NUM>. In one example, as shown in <FIG> and <FIG>, the liquid supply reservoir <NUM> may include a valve <NUM>.

As shown in <FIG>, the valve <NUM> can be a check valve configured to maintain the liquid material within the liquid supply reservoir and to open when the liquid supply reservoir <NUM> is squeezed and pressure is applied to the reservoir <NUM>. In one example, the check valve <NUM> opens when a critical, minimum pressure is reached so as to avoid inadvertent dispensing of liquid material from the liquid supply reservoir <NUM> or activating the heater <NUM>. In one example, the critical pressure needed to open the check valve <NUM> is essentially equal to or slightly less than the pressure required to apply a pressure switch <NUM> to activate the heater <NUM>. In one example, the pressure required to press the pressure switch <NUM> is high enough such that accidental heating is avoided. Such arrangement avoids activation of the heater <NUM> in the absence of liquid being pumped through the capillary.

Advantageously, the use of a check valve <NUM> aids in limiting the amount of liquid that is drawn back from the capillary tube upon release of pressure upon the liquid supply reservoir <NUM>, the switch <NUM>, or both, if manually pumped so as to avoid air uptake into the liquid supply reservoir <NUM>. Presence of air degrades pumping performance of the liquid supply reservoir <NUM> and can degrade the liquid formulation.

Once pressure upon the liquid supply reservoir <NUM> is relieved, the valve <NUM> closes. The heated capillary tube <NUM> discharges any liquid remaining downstream of the valve <NUM>.

Optionally, a critical flow orifice <NUM> is located downstream of the check valve <NUM> to establish a maximum flow rate of liquid to the capillary tube <NUM>.

As shown in <FIG>, in other examples, the valve <NUM> can be a two-way valve and the liquid supply reservoir <NUM> can be pressurized. For example, the liquid supply reservoir <NUM> can be pressurized using a pressurization arrangement <NUM> configured to apply constant pressure to the liquid supply reservoir <NUM>. For example, pressure can be applied to the liquid supply reservoir <NUM> using an internal or external spring and plate arrangement which constantly applies pressure to the liquid supply reservoir <NUM>. Alternatively, the liquid supply reservoir <NUM> can be compressible and positioned between two plates that are connected by springs or the liquid supply reservoir <NUM> could be compressible and positioned between the outer housing and a plate that are connected by a spring so that the plate applies pressure to the liquid supply reservoir <NUM>.

In one example, the capillary tube <NUM> of <FIG> and <FIG> has an internal diameter of about <NUM> millimetres to about <NUM> millimetres, preferably about <NUM> millimetres to about <NUM> millimetre, and more preferably about <NUM> millimetres to about <NUM> millimetres. Capillary tubes of smaller diameter provide more efficient heat transfer to the fluid because, with the shorter distance to the center of the fluid, less energy and time is required to vaporize the liquid.

In one example, the capillary tube <NUM> may have a length of about <NUM> millimetres to about <NUM> millimetres, more preferably about <NUM> millimetres to about <NUM> millimetres or about <NUM> millimetres to about <NUM> millimetres. In one example, the capillary tube <NUM> is substantially straight. In other examples, the capillary tube <NUM> is coiled or includes one or more bends therein to conserve space, accommodate a long capillary tube, or both.

In some examples, the capillary tube <NUM> is formed of or includes a conductive material, and thus acts as its own heater <NUM> by passing current through the tube. The capillary tube <NUM> may be any electrically conductive material capable of being resistively heated, while retaining the necessary structural integrity at the operating temperatures experienced by the capillary tube <NUM>, and which is non-reactive with the liquid material. Suitable materials for forming the capillary tube <NUM> are one or more of stainless steel, copper, copper alloys, porous ceramic materials coated with film resistive material, Inconel® available from Special Metals Corporation, which is a nickel-chromium alloy, nichrome, which is also a nickel-chromium alloy, and combinations thereof.

In one example, the capillary tube <NUM> is a stainless steel capillary tube <NUM>, which serves as a heater <NUM> via electrical leads <NUM> attached thereto for passage of direct or alternating current along a length of the capillary tube <NUM>. Thus, the stainless steel capillary tube <NUM> is heated by resistance heating. The stainless steel capillary tube <NUM> may be circular in cross section and may be formed of or include tubing suitable for use as a hypodermic needle of various gauges. For example, the capillary tube <NUM> may comprise a <NUM> gauge needle having an internal diameter of about <NUM> millimetres and a <NUM> gauge needle having an internal diameter of about <NUM> millimetres.

In another example, the capillary tube <NUM> may be a non-metallic tube such as, for example, a glass tube. In such an example, the heater <NUM> is formed of or includes a conductive material capable of being resistively heated, such as, for example, stainless steel, nichrome or platinum wire, arranged along the glass tube. When the heater arranged along the glass tube is heated, liquid material in the capillary tube <NUM> is heated to a temperature sufficient to at least partially volatilize liquid material in the capillary tube <NUM>.

In one example, at least two electrical leads <NUM> (<FIG>) are bonded to a metallic capillary tube <NUM>. In an example, the at least two electrical leads <NUM> are coupled to the capillary tube <NUM>. In one example, one electrical lead <NUM> is coupled to a first, upstream portion <NUM> of the capillary tube <NUM> and a second electrical lead <NUM> is coupled to a downstream, end portion <NUM> of the capillary tube <NUM>, as shown in <FIG> and <FIG>.

In operation, once the capillary tube <NUM> of <FIG> and <FIG> is heated, the liquid material contained within a heated portion of the capillary tube <NUM> is volatilized and ejected out of the outlet <NUM> where the liquid material expands and mixes with air and forms a vapor in a mixing chamber <NUM>.

As discussed above and illustrated in <FIG>, the liquid formulation can also be used in an e-vaping device including a heater zone having at least one heater <NUM> and a filamentary wick <NUM>. The first section <NUM> includes an outer tube (or casing) <NUM> extending in a longitudinal direction and an inner tube (or chimney) <NUM> coaxially positioned within the outer tube <NUM>. In one example, a nose portion <NUM> of an upstream gasket (or seal) <NUM> is fitted into an upstream end portion <NUM> of the inner tube <NUM>, while at the same time, an outer perimeter <NUM> of the gasket <NUM> provides a liquid-tight seal with an interior surface <NUM> of the outer casing <NUM>. The upstream gasket <NUM> also includes a central, longitudinal air passage <NUM>, which opens into an interior of the inner tube <NUM> that defines a central channel <NUM>. A transverse channel <NUM> at an upstream portion of the gasket <NUM> intersects and communicates with the central, longitudinal air passage <NUM> of the gasket <NUM>. This channel <NUM> assures communication between the central, longitudinal air passage <NUM> and a space <NUM> defined between the gasket <NUM> and a threaded connection <NUM>.

In one example, a nose portion <NUM> of a downstream gasket <NUM> is fitted into a downstream end portion <NUM> of the inner tube <NUM>. An outer perimeter <NUM> of the gasket <NUM> provides a substantially liquid-tight seal with an interior surface <NUM> of the outer casing <NUM>. The downstream gasket <NUM> includes a central channel <NUM> disposed between the central passage <NUM> of the inner tube <NUM> and the mouth-end insert <NUM>.

In this example, the liquid supply reservoir <NUM> is contained in an annulus between an inner tube <NUM> and an outer casing <NUM> and between the upstream gasket <NUM> and the downstream gasket <NUM>. Thus, the liquid supply reservoir <NUM> at least partially surrounds the central air passage <NUM>. The liquid supply reservoir <NUM> comprises a liquid material and optionally a liquid storage medium (not shown) configured to store the liquid material therein.

The inner tube <NUM> has a central air passage <NUM> extending therethrough and that houses the heater <NUM>. The heater <NUM> is in contact with the filamentary wick <NUM>, which preferably extends between opposing sections of the liquid supply reservoir <NUM> so as to deliver the liquid formulation from the liquid supply reservoir to the heater <NUM>.

In one example, the e-vaping device <NUM> described herein also includes at least one air inlet <NUM>. As shown in <FIG>, the at least one air inlet <NUM> can be located upstream of the heater <NUM>.

In the examples illustrated in <FIG> and <FIG>, the at least one air inlet <NUM> is preferably arranged downstream of the capillary tube <NUM> so as to minimize drawing air along the capillary tube and thereby avoid cooling of the capillary tube <NUM> during heating cycles.

In the examples, the at least one air inlet <NUM> includes one or two air inlets. Alternatively, there may be three, four, five or more air inlets. Altering the size and number of air inlets <NUM> can also aid in establishing the resistance to draw of the e-vaping device <NUM>.

The power supply <NUM> of the examplescan include a battery or power supply <NUM> arranged in the e-vaping device <NUM>. The power supply <NUM> is configured to apply voltage across the heater <NUM> associated with the capillary tube <NUM>, as shown in <FIG> and <FIG>, or the heater <NUM> associated with the wick <NUM>, as shown in <FIG>. Thus, the heater <NUM> or <NUM> volatilizes liquid material according to a power cycle of either a predetermined time period, such as a <NUM> to <NUM> second period.

In one example, the electrical contacts or connection between the heater <NUM>, <NUM> and the electrical leads <NUM> are substantially conductive and temperature resistant while the heater <NUM>, <NUM> is substantially resistive so that heat generation occurs primarily along the heater <NUM> and not at the contacts.

The battery <NUM> can be a lithium-ion battery or one of its variants, for example a lithium-ion polymer battery. Alternatively, the battery may be a nickel-metal hydride battery, a nickel cadmium battery, a lithium-manganese battery, a lithium-cobalt battery or a fuel cell. In that case, preferably, the e-vaping device <NUM> is usable by a smoker until the energy in the power supply is depleted. Alternatively, the power supply <NUM> may be rechargeable and include circuitry allowing the battery to be chargeable by an external charging device. In that case, preferably the circuitry, when charged, provides power for a pre-determined number of puffs, after which the circuitry must be re-connected to an external charging device.

In one example, the e-vaping device <NUM> also includes control circuitry which can be on a printed circuit board <NUM> (shown in <FIG>, <FIG>). The control circuitry <NUM> can also include a heater activation light <NUM> that is configured to glow when the heater <NUM>, <NUM> is activated. In one example, the heater activation light <NUM> comprises at least one LED and is at an upstream end <NUM> (shown in <FIG>) of the e-vaping device <NUM> so that the heater activation light <NUM> illuminates a cap which takes on the appearance of a burning coal during use. Moreover, the heater activation light <NUM> can be configured to be visible to the adult vaper. In addition, the heater activation light <NUM> can be utilized for smoking article system diagnostics. The light <NUM> can also be configured such that the adult vaper can activate, deactivate, or activate and deactivate the light <NUM> when desired, such that the light <NUM> would not activate during vaping if desired.

The time-period of the electric current supply to the heater <NUM> may be pre-set depending on the amount of liquid desired to be vaporized. The control circuitry <NUM> can be programmable and can include an application specific integrated circuit (ASIC). In other examples, the control circuitry <NUM> can include a microprocessor programmed to carry out functions such as heating the capillary tubes, operating the valves, or both.

As shown in <FIG>, <FIG>, the e-vaping device <NUM> further includes a mouth-end insert <NUM> having at least two off-axis, preferably diverging outlets <NUM>. In one example, the mouth-end insert <NUM> includes at least two diverging outlets <NUM> (for example, <NUM>, <NUM>, <NUM>, <NUM> to <NUM> outlets or more). In one example, the outlets <NUM> of the mouth-end insert <NUM> are located at ends of off-axis passages <NUM> and are angled outwardly in relation to the longitudinal direction of the e-vaping device <NUM> (i.e., divergently). As used herein, the term "off-axis" denotes at an angle to the longitudinal direction of the e-vaping device. Also preferably, the mouth-end insert (or flow guide) <NUM> includes outlets uniformly distributed around the mouth-end insert <NUM> so as to substantially uniformly distribute vapor in a user's mouth during use.

In addition, the outlets <NUM> and off-axis passages <NUM> are arranged such that droplets of unvaporized liquid material carried in the vapor impact at least one of interior surfaces of the mouth-end insert <NUM> and interior surfaces of the off-axis passages <NUM> such that the droplets are removed or broken apart.

In one example, one or more of the outlets <NUM> may have a diameter of about <NUM> inch to about <NUM> inch (for example, about <NUM> inch to about <NUM> inch or about <NUM> inch to about <NUM> inch). The size of the outlets <NUM> and off-axis passages <NUM> along with the number of outlets <NUM> can be selected to adjust the resistance to draw (RTD) of the e-vaping device <NUM>, if desired.

In one example, the e-vaping device <NUM> is about the same size as a tobacco-based smoking article. In some examples, the e-vaping device <NUM> can be about <NUM> millimetres to about <NUM> millimetres long, preferably about <NUM> millimetres to about <NUM> millimetres long and about <NUM> millimetres to about <NUM> millimetres in diameter. For example, in one example, the e-vaping device is about <NUM> millimetres long and has a diameter of about <NUM> millimetres.

The outer cylindrical housing <NUM> of the e-vaping device <NUM> may be formed of or include any suitable material or combination of materials. In one example, the outer cylindrical housing <NUM> is formed at least partially of metal and is part of the electrical circuit.

In one example, the liquid formulation may include one of more acids from pyruvic acid, formic acid, oxalic acid, acetic acid, isovaleric acid, valeric acid, propionic acid, octanoic acid, lactic acid, levulinic acid, sorbic acid, malic acid, tartaric acid, succinic acid, citric acid, benzoic acid, oleic acid, aconitic acid, butyric acid, cinnamic acid, decanoic acid, <NUM>,<NUM>-diemthyl-<NUM>-octenoic acid, <NUM>-glutamic acid, heptanoic acid, hexanoic acid, <NUM>-hexenoic acid, trans-<NUM>-hexenoic acid, isobutyric acid, lauric acid, <NUM>-methylbutyric acid, <NUM>-methylvaleric acid, myristic acid, nonanoic acid, palmitic acid, <NUM>-pentenoic acid, phenylacetic acid, <NUM>-phenylpropionic acid, hydrochloric acid, phosphoric acid, sulfuric acid and combinations thereof. The acid also may be incorporated into the liquid formulation in the form of a salt. In one example, the salt form of the acid is selected such that the addition of the acid does not have significant adverse effects on one or both of the vapor transfer efficiency and the reaction of the corresponding free acid form with nicotine.

The acids included in the liquid formulation can have a boiling point of at least about <NUM> degrees Celsius. For example, the acids may have a boiling point ranging from about <NUM> degrees Celsius to about <NUM> degrees Celsius or from about <NUM> degrees Celsius to about <NUM> degrees Celsius (for example, about <NUM> degrees Celsius to about <NUM> degrees Celsius, about <NUM> degrees Celsius to about <NUM> degrees Celsius, about <NUM> degrees Celsius to about <NUM> degrees Celsius or about <NUM> degrees Celsius to about <NUM> degrees Celsius). By including acids having a boiling point within this range, the acid may volatilize when heated by heater elements of e-vaping devices as previously described. In one example utilizing a heater coil and a wick, the heater coil may reach an operating temperature at or about <NUM> degrees Celsius.

Claim 1:
A liquid formulation for an e-vaping device, the liquid formulation comprising:
a vapor former including propylene glycol, water and substantially no amount of glycerol, wherein a concentration of propylene glycol in the vapor former is <NUM> percent by weight and a concentration of water in the vapor former is <NUM> percent by weight;
nicotine, wherein a concentration of nicotine in the liquid formulation is equal to or lower than <NUM> percent by weight; and
one or more acids,
wherein the liquid formulation is configured to form a vapor having a particulate phase and a gas phase when heated in the e-vaping device.