PATENT ABSTRACT
A cartomizer section of an electronic cigarette can be connected to a battery section of the electronic cigarette. The cartomizer section comprises a liquid reservoir operable to store liquid material and a one-way valve. The one-way valve is operable to seal an end of the cartomizer section which is in fluid communication with the liquid reservoir. The one-way valve is configured to allow one directional air flow towards a user&#39;s mouth during a draw on the electronic cigarette so as to prevent back flow of vapor produced during operation of the electronic cigarette towards the battery section.

PATENT DESCRIPTION
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 61/827,998, filed on May 28, 2013, the entire content of which is incorporated herein by reference thereto. 
     
    
     FIELD 
       [0002]    This application relates to a device and method for preventing the back flow of liquid and vapor from a cartomizer section into a battery section of an electronic cigarette, and an improved method of sealing a cartomizer section during storage thereof through the use of a one-way valve included in the cartomizer section. 
       BACKGROUND 
       [0003]    Electronic cigarettes are becoming a popular alternative to tobacco smoking because of the many advantages that they offer. One of the main reasons that they are popular is due to their similarities to tobacco smoking. In fact, the closer that they are in providing the experience of a traditional cigarette, the more likely they are to be accepted in the market place. 
         [0004]    One example of an electronic cigarette is a “two-piece” (hereinafter referred to as a “two-piece”) device having a first battery section B and a second cartomizer section A, wherein the cartomizer section A is detachable from the battery section B (hereinafter an “Electronic Cigarette” or “E-cigarette”). An example of one such Electronic Cigarette is shown in  FIGS. 1 and 2 . In some embodiments, the battery section B contains a power cell, a chipset (i.e. control circuitry) and an airflow sensor. In some embodiments, the cartomizer section A contains a heating element and a container (reservoir) of “e-liquid” which comprises flavorings and a vaporizing base, such as glycol (hereinafter referred to as the “cartomizer”). The battery section and cartomizer section can be physically and electrically connected by a threaded engagement. In some embodiments, the battery section has the “male” threaded portion and the cartomizer section has the “female” threaded portion, as shown in  FIG. 2 . 
         [0005]    Early E-cigarettes had one or more notches at the tip of the battery section to allow air intake. Air would enter from the tip, pass through the entire battery section, and continue through the cartomizer section, the vapor-producing portion of the E-cigarette, and enter the smoker&#39;s mouth via an opening in the mouth end insert of the cartomizer section. When a typical smoker puffs on an electronic cigarette, he/she may inadvertently or intentionally exhale into the cigarette, reversing the vapor flow from his/her mouth into the cigarette. This vapor often condenses and eventually builds up inside the battery, causing damage to the flow sensor, chipset and/or the lithium cell. 
         [0006]    To avoid this kind of damage, electronic cigarettes were designed with side vents. When the user inhales, the air enters the cigarette through side holes that are located between the cartomizer section and battery section. Similarly, when the smoker exhales into the e-cigarette, the vapor from his/her mouth travels in the reverse direction, and escapes through the side vents. With this construction, there is minimal air passage through the battery section. However, an opening into the battery section is still necessary to allow the flow sensor inside to sense a puff and activate the heating coil. An example of an electronic cigarette with side vents is disclosed in WO 2012/142293 the entire contents of which is incorporated by reference herein. 
         [0007]    As such, e-cigarettes which include side vents that allow most of the vapor to exit through the side vents thereof during exhalation still include an opening for the vapor to travel into the battery section , which thereby exposes the components within the battery section to the damaging effects of the vapor. It is therefore advantageous to prevent the vapor from leaving the cartomizer section and continuing in the direction of battery components included in the battery section, to avoid its damaging effects on the battery components. 
         [0008]    In contrast to two-piece cigarettes, there are e-cigarettes which encase the battery section and cartomizer section into one integrated housing which saves production costs and eliminates the need for assembly before use thereof. Such electronic cigarettes are often called “one-piece units” or “disposable cigarettes” (hereinafter referred to as a “disposables”). 
         [0009]    Although disposables are convenient for the user, they present difficulties for long term storage and shelf life. Disposables lack some of the advantages of a two-piece. For example, when the cartomizer section is separate from the battery section, the ends of the cartomizer section can be sealed with caps or plugs. Sealing the two ends of the cartomizer section prevents moisture in the environment from being absorbed by the e-liquid, which often decreases the viscosity of the e-liquid and can cause leaking of the e-liquid into a user&#39;s mouth during smoking. The seals also prevent e-liquid or nicotine from evaporating or dripping out of the cartomizer section. 
         [0010]    In disposables, there is typically no seal between the cartomizer section and the battery section, and if e-liquid drains into the air path of the cartomizer section, it can easily drain upstream into the battery section, thereby damaging the flow sensor, chipset and/or the lithium cell that are housed in the battery section. Additionally, without the presence of a seal between the cartomizer and battery sections, the e-liquid eventually evaporates, as well as the nicotine, which greatly impairs the effectiveness of the e-liquid as well as the user&#39;s experience. Also, lack of a seal allows ambient air moisture to enter the cartomizer section, which is then readily absorbed into the hydrophilic e-liquid, increasing the e-liquid&#39;s volume, and lowering the viscosity of the e-liquid, resulting in leakage of excess e-liquid. 
         [0011]    Therefore, it is desirable to have a method of preventing the e-liquid in the cartomizer section from escaping into the battery section, and air moisture from the battery section from entering the cartomizer section when not in use. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  illustrates an electronic cigarette according to embodiments disclosed herein. 
           [0013]      FIG. 2  illustrates an electronic cigarette including a cartomizer section which is detachable from a battery section according to embodiments disclosed herein. 
           [0014]      FIGS. 3A-3D  illustrate embodiments of a one-way valve. 
           [0015]      FIG. 4A-4C  illustrate embodiments of a one-way valve. 
           [0016]      FIG. 5  illustrates a cross-section of a cartomizer section including a one-way valve according to embodiments disclosed herein. 
           [0017]      FIG. 6  illustrates an embodiment of an electronic cigarette including a one-way valve installed onto a post in a cartomizer section thereof according to embodiments disclosed herein. 
       
    
    
     SUMMARY 
       [0018]    Disclosed herein is a cartomizer section of an electronic cigarette which can be connected to a battery section of the electronic cigarette. The cartomizer section comprises a liquid reservoir operable to store liquid material and a one-way valve. The one-way valve is operable to seal an end of the cartomizer section which is in fluid communication with the liquid reservoir. The one-way valve is configured to allow one directional air flow towards a user&#39;s mouth during a draw on the electronic cigarette so as to prevent back flow of vapor produced during operation of the electronic cigarette towards the battery section thereof. 
       DESCRIPTION 
       [0019]    Disclosed herein is a one-way valve that can be included in a cartomizer section of an electronic cigarette, allowing one directional air flow towards a user&#39;s mouth, while preventing back flow of vapor or e-liquid towards the battery section of the electronic cigarette. Accordingly, during prolonged storage, the one-way valve provides a seal for the cartomizer section, which prevents e-liquid stored in a liquid reservoir of the cartomizer section from draining into the battery section, and greatly reduces evaporation of e-liquid and nicotine out of the cartomizer section. Additionally, the one-way valve prevents ambient air moisture from being absorbed into the e-liquid, preserving its viscosity and preventing leaking. 
         [0020]    In another embodiment, sealing properties of the one-way valve allows for disposable electronic cigarettes to be stored for extended periods with minimal loss of e-liquid and nicotine potency, greatly extending the shelf life thereof. Additionally, because the one-way valve prevents the flow of excess e-liquid into the battery section, there is no longer a limitation on the orientation of the disposables during transportation or storage. Whereas before, one had to store and ship the disposables in an upright position with the battery section oriented above the cartomizer section to avoid leakage of e-liquid into the battery section, embodiments as disclosed herein allow for the disposables to be stored and shipped in any orientation. 
         [0021]    The one-way valve extends the longevity of the electronic cigarette by preventing the back flow of vapor towards the battery section, thereby eliminating the damage typically caused by vapor on the battery components of the battery section. 
         [0022]    Additionally, the one-way valve provides a seal between the cartomizer section and the battery section which can extend the life of the e-liquid of the electronic cigarette between smoking sessions. The presence of a one-way valve prevents liquid leakage and evaporation of e-liquid from the distal end of the cartomizer section. A plug can be used to seal the mouth end insert of the cartomizer section or disposable between uses. 
         [0023]      FIGS. 3A-D  and  FIGS. 4A-C  illustrate embodiments of a one-way valve  300  as disclosed herein. According to an embodiment, a one-way valve  300  can be formed as a generally cylindrical shape forming an elongated portion  320  with one end that is blocked which forms a valve face  305 . The valve face  305  can have a cut or a slit  310  on a surface thereof The cut or slit  310  can extend across the entire surface (along the diameter) of the valve face  305 . Two flaps  315   a,b  are formed on opposite sides of the slit  310 . Under normal storage conditions or between puffs, the two flaps  315   a,b  on opposite sides of the slit  310  can be situated tightly adjacent to each other so as to form a tight seal against air and e-liquid. 
         [0024]    In an alternative embodiment, the valve face  305  can include more than one slit thereon wherein the slits can be made by making 3 or 4 (criss-cross) symmetrical cuts on the valve face  305 , thus creating 3 or 4 flaps respectively. Alternatively, the slits  310  do not need to be straight or symmetrical. They can be wavy, saw-toothed or virtually any shape imaginable. 
         [0025]    The one-way valve  300  should be preferably made of a flexible and/or stretchable material such as rubber or silicone, so that when the smoker inhales, a vacuum is formed above the surface of the valve face  305 , creating a negative pressure. This negative pressure pulls the flaps  315   a,b  on opposite sides of the slit  310  to fold up and away from each other, forming an air pathway in the direction towards a mouth of the user. If a user exhales or blows into the e-cigarette, a positive pressure is applied on the surface of the valve face  305 , forcing the flaps  315   a,b  to go back to their original shape and block the back flow of vapor. Alternatively, the one-way valve  300  can be made of one material or a composite of materials, and does not necessarily need to have uniform flexibility and elasticity throughout. For instance, the flaps  315   a,b  can include edges or “lips”  316   a,b  (see  FIG. 4B ) along the slit  310  which may be made more rigidly than the flaps  315   a,b , and the opening motion can occur at the joints where the “lips”  316   a,b  meet at the extremities of the slit  310 . 
         [0026]      FIG. 5  depicts a schematic of a cutaway section of a cartomizer section  500  including a one-way valve  300 . Some components of the cartomizer section  500  have been removed for the purpose of simplicity. The cartomizer section can include a liquid reservoir, heating coil, an air channel (i.e. airflow path) and other components as shown in WO 2012/142293. As can be seen in  FIG. 5 , the cartomizer section  500  can be generally cylindrical and can include a center space  505  therein. The center space  505  can include a metal or plastic “post”  510  which can protrude in an axial direction of the cartomizer section  500  towards a mouth end insert  650  (see  FIG. 6 ). The one-way valve  300  should be made of the correct size so as to fit tightly onto the post  510  of the cartomizer section  500 . Preferably, when the one-way valve  300  is on the post  510 , the cylindrical length of the one-way valve  300  should be such that the valve face  305  of the valve  300  should either sit directly on the top of the post  510  (to prevent the flaps from opening in the wrong direction) or it should extend at least slightly beyond the top of the post  510  (up to 3 mm). 
         [0027]    The valve face  305  should preferably be axially spaced from a heater such as a heating coil  620  (see  FIG. 6 ) so that it does not melt or warp from the elevated heat of the heater. It is therefore also recommended to preferably make the valve out of a heat resistant material such as for example silicone. 
         [0028]      FIG. 6  depicts a cutaway section of an electronic cigarette  600 , also showing a one-way valve  300  installed onto a post  510  in a cartomizer section  601 . The electronic cigarette  600  can include a separate cartomizer section  601  which is disposable and a separate battery section  602  which is reusable, or alternatively, the cartomizer section  601  and the battery section  602  can be an integral piece wherein the electronic cigarette  600  is disposable. As shown in  FIG. 6 , the valve face  305  of the one-way valve  300  is located between the top of the post  510  and the heating coil  620 . The battery section  602  can include an airflow sensor, battery, and other components as shown in WO 2012/142293. 
         [0029]    Although the elongated portion  320  of the one-way valve  300  is typically cylindrical, it can alternatively have a square, rectangular or virtually any-shaped cross-section. In fact, that elongated portion  320  of the one-way valve  300  does not necessarily need to exist, and indeed, just the valve face  305  of the one-way valve  300  is enough for the one-way valve  300  to function. As seen from  FIGS. 3A-D  and  4 A-C, the valve face  305  can be flat (see  FIGS. 4A-C ), or contoured and protruding (See  FIGS. 3A-D ). For example, as illustrated in  FIGS. 3A and 3B , the valve face  305  of the one-way valve can protrude outwardly, or alternatively, as illustrated in  FIG. 3D , the valve face  305  of the one-way valve  300  can be contoured such that the slit  310  of the valve face  305  fits in a recess thereof. 
         [0030]    It will be understood that the embodiments disclosed herein have been disclosed herein by way of example, and that other modifications and alterations may occur to those skilled in the art without departing from the scope of the embodiments disclosed herein.