Patent Publication Number: US-2023148673-A1

Title: Electronic smoking device with liquid filling valve

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation of U.S. application Ser. No. 16/954,467, filed 16 Jun. 2020 (the &#39;467 application), which is the national stage of international application no. PCT/EP2018/085500, filed 18 Dec. 2018 and published in English on 27 Jun. 2019 under international publication no. WO 2019/121684 (the &#39;500 application), which claims priority to European application no. 17208252.1, filed 18 Dec. 2017 (the &#39;252 application), and claims priority to European application no. 17208247.1, filed 18 Dec. 2017 (the &#39;247 application). The &#39;467 application, the &#39;500 application, the &#39;252 application, and the &#39;247 application are all hereby incorporated by reference in their entirety as though fully set forth herein. 
    
    
     FIELD OF INVENTION 
     The present invention relates generally to electronic smoking devices and in particular electronic cigarettes. The present invention in particular relates to electronic smoking devices having a refillable liquid reservoir. 
     BACKGROUND OF THE INVENTION 
     An electronic smoking device, such as an electronic cigarette (e-cigarette), typically has a housing accommodating an electric power source (e.g. a single use or rechargeable battery, electrical plug, or other power source), and an electrically operable atomizer. The atomizer vaporizes or atomizes liquid supplied from a reservoir and provides vaporized or atomized liquid as an aerosol. Control electronics control the activation of the atomizer. In some electronic cigarettes, an airflow sensor is provided within the electronic smoking device, which detects a user puffing on the device (e.g., by sensing an under-pressure or an air flow pattern through the device). The airflow sensor indicates or signals the puff to the control electronics to power up the device and generate vapor. In other e-cigarettes, a switch is used to power up the e-cigarette to generate a puff of vapor. 
     An electronic smoking device can be adapted to allow refilling a liquid reservoir. 
     SUMMARY OF THE INVENTION 
     In accordance with one aspect of the present invention, there is provided an electronic smoking device that comprises a power supply portion comprising a power supply, and an atomizer/liquid reservoir portion. The atomizer/liquid reservoir portion comprises a refillable liquid reservoir adapted for storing liquid, and an atomizer operable when connected to the power supply to atomize liquid stored in the liquid reservoir. The atomizer/liquid reservoir portion comprises a docking valve for docking a source of liquid to be stored in the liquid reservoir, and a liquid duct that is adapted to receive liquid from the docking valve. The liquid duct opens into the refillable liquid reservoir at a distance to the docking valve. 
     The characteristics, features and advantages of this invention and the manner in which they are obtained as described above, will become more apparent and be more clearly understood in connection with the following description of exemplary embodiments, which are explained with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, same element numbers indicate same elements in each of the views: 
         FIG.  1    is a schematic cross-sectional illustration of an exemplary e-cigarette; 
         FIGS.  2  to  7    show an exemplary embodiment of an e-cigarette in ready-for-use and in refill states; 
         FIGS.  8  to  10    depict the exemplary embodiment of  FIGS.  2  to  7    in a schematic cross-sectional view; 
         FIG.  11    illustrates the exemplary embodiment of  FIGS.  2  to  10    in another schematic cross-sectional view; and 
         FIG.  12    illustrates the exemplary embodiment of  FIGS.  2  to  11    in another schematic cross-sectional view. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Throughout the following, an electronic smoking device will be exemplarily described with reference to an e-cigarette. As is shown in  FIG.  1   , an e-cigarette  10  typically has a housing comprising a cylindrical hollow tube having an end cap  16 . The cylindrical hollow tube may be a single-piece or a multiple-piece tube. In  FIG.  1   , the cylindrical hollow tube is shown as a two-piece structure having a power supply portion  12  and an atomizer/liquid reservoir portion  14 . Together the power supply portion  12  and the atomizer/liquid reservoir portion  14  form a cylindrical tube which can be approximately the same size and shape as a conventional cigarette, typically about 100 mm with a 7.5 mm diameter, although lengths may range from 70 to 150 or 180 mm, and diameters from 5 to 28 mm. 
     The power supply portion  12  and atomizer/liquid reservoir portion  14  are typically made of metal, e.g. steel or aluminum, or of hardwearing plastic and act together with the end cap  16  to provide a housing to contain the components of the e-cigarette  10 . The power supply portion  12  and an atomizer/liquid reservoir portion  14  may be configured to fit together by a friction push-fit, a snap-fit, or a bayonet attachment, magnetic-fit, or screw threads. The end cap  16  is provided at the front end of the power supply portion  12 . The end cap  16  may be made from translucent plastic or other translucent material to allow a light-emitting diode (LED)  20  positioned near the end cap to emit light through the end cap. The end cap can be made of metal or other materials that do not allow light to pass. 
     An air inlet may be provided in the end cap, at the edge of the inlet next to the cylindrical hollow tube, anywhere along the length of the cylindrical hollow tube, or at the connection of the power supply portion  12  and the atomizer/liquid reservoir portion  14 .  FIG.  1    shows a pair of air inlets  38  provided at the intersection between the power supply portion  12  and the atomizer/liquid reservoir portion  14 . 
     A power supply, preferably a battery  18 , an LED  20 , control electronics  22  and optionally an airflow sensor  24  are provided within the cylindrical hollow tube power supply portion  12 . The battery  18  is electrically connected to the control electronics  22 , which are electrically connected to the LED  20  and the airflow sensor  24 . In this example, the LED  20  is at the front end of the power supply portion  12 , adjacent to the end cap  16  and the control electronics  22  and airflow sensor  24  are provided in the central cavity at the other end of the battery  18  adjacent to the atomizer/liquid reservoir portion  14 . 
     The airflow sensor  24  acts as a puff detector, detecting a user puffing or sucking on the atomizer/liquid reservoir portion  14  of the e-cigarette  10 . The airflow sensor  24  can be any suitable sensor for detecting changes in airflow or air pressure, such as a microphone switch including a deformable membrane which is caused to move by variations in air pressure. Alternatively, the sensor may be a Hall element or an electro-mechanical sensor. 
     The control electronics  22  are also connected to an atomizer  26 . In the example shown, the atomizer  26  includes a heating coil  28  which is wrapped around a wick  30  extending across a central passage  32  of the atomizer/liquid reservoir portion  14 . The coil  28  may be positioned anywhere in the atomizer  26  and may be transverse or parallel to the liquid reservoir  34 . The wick  30  and heating coil  28  do not completely block the central passage  32 . Rather an air gap is provided on either side of the heating coil  28  enabling air to flow past the heating coil  28  and the wick  30 . The atomizer may alternatively use other forms of heating elements, such as ceramic heaters, or fiber or mesh material heaters. Nonresistance heating elements such as sonic, piezo and jet spray may also be used in the atomizer in place of the heating coil. 
     The central passage  32  is surrounded by a cylindrical liquid reservoir  34  with the ends of the wick  30  abutting or extending into the liquid reservoir  34 . The wick  30  may be a porous material such as a bundle of fiberglass fibers, with liquid in the liquid reservoir  34  drawn by capillary action from the ends of the wick  30  towards the central portion of the wick  30  encircled by the heating coil  28 . 
     The liquid reservoir  34  may alternatively include wadding soaked in liquid which encircles the central passage  32  with the ends of the wick  30  abutting the wadding. In other embodiments, the liquid reservoir  34  may comprise a toroidal cavity arranged to be filled with liquid and with the ends of the wick  30  extending into the toroidal cavity. 
     An air inhalation port  36  is provided at the back end of the atomizer/liquid reservoir portion  14  remote from the end cap  16 . The inhalation port  36  may be formed from the cylindrical hollow tube atomizer/liquid reservoir portion  14  or maybe formed in an end cap. 
     In use, a user sucks on the e-cigarette  10 . This causes air to be drawn into the e-cigarette  10  via one or more air inlets, such as air inlets  38 , and to be drawn through the central passage  32  towards the air inhalation port  36 . The change in air pressure which arises is detected by the airflow sensor  24 , which generates an electrical signal that is passed to the control electronics  22 . In response to the signal, the control electronics  22  activate the heating coil  28 , which causes liquid present in the wick  30  to be vaporized, creating an aerosol (which may comprise gaseous and liquid components) within the central passage  32 . As the user continues to suck on the e-cigarette  10 , this aerosol is drawn through the central passage  32  and inhaled by the user. At the same time, the control electronics  22  also activate the LED  20  causing the LED  20  to light up which is visible via the translucent end cap  16  mimicking the appearance of a glowing ember at the end of a conventional cigarette. As liquid present in the wick  30  is converted into an aerosol, more liquid is drawn into the wick  30  from the liquid reservoir  34  by capillary action and thus is available to be converted into an aerosol through subsequent activation of the heating coil  28 . 
     Some e-cigarettes are intended to be disposable and the electric power in the battery  18  is intended to be sufficient to vaporize the liquid contained within the liquid reservoir  34 , after which the e-cigarette  10  is thrown away. In other embodiments the battery  18  is rechargeable and the liquid reservoir  34  is refillable. In the cases where the liquid reservoir  34  is a toroidal cavity, this may be achieved by refilling the liquid reservoir  34  via a refill port. In other embodiments the atomizer/liquid reservoir portion  14  of the e-cigarette  10  is detachable from the power supply portion  12  and a new atomizer/liquid reservoir portion  14  can be fitted with a new liquid reservoir  34  thereby replenishing the supply of liquid. In some cases, replacing the liquid reservoir  34  may involve replacement of the heating coil  28  and the wick  30  along with the replacement of the liquid reservoir  34 . A replaceable unit comprising the atomizer  26  and the liquid reservoir  34  is called a cartomizer. 
     The new liquid reservoir  34  may be in the form of a cartridge having a central passage  32  through which a user inhales aerosol. In other embodiments, aerosol may flow around the exterior of the cartridge  32  to an air inhalation port  36 . 
     Of course, in addition to the above description of the structure and function of a typical e-cigarette  10 , variations also exist. For example, the LED  20  may be omitted. The airflow sensor  24  may be placed adjacent to the end cap  16  rather than in the middle of the e-cigarette. The airflow sensor  24  may be replaced with a switch which enables a user to activate the e-cigarette manually rather than in response to the detection of a change in air flow or air pressure. 
     Different types of atomizers may be used. Thus, for example, the atomizer may have a heating coil in a cavity in the interior of a porous body soaked in liquid. In this design aerosol is generated by evaporating the liquid within the porous body either by activation of the coil heating the porous body or alternatively by the heated air passing over or through the porous body. Alternatively, the atomizer may use a piezoelectric atomizer to create an aerosol either in combination or in the absence of a heater. 
       FIGS.  2  to  7    show another exemplary embodiment of the e-cigarette  100  in ready-to-use and refill states. The e-cigarette  100  comprises the power supply portion  112  and the atomizer/liquid reservoir portion  114 . 
     Optionally, the power supply portion  112  is removable from the atomizer/liquid reservoir portion  114  or vice versa. 
       FIG.  2    shows the c-cigarette  100  in a ready-to-use state, in which a user of the e-cigarette  100  can use the e-cigarette  100  for vaping, i.e. for inhaling the atomized liquid storable in the atomizer/liquid reservoir portion  114 . In the ready-to-use state, a mouthpiece cap  140  of the e-cigarette  100  is arranged in its vaping position V, in which the mouthpiece cap  140  borders, i.e. directly contacts, the atomizer/liquid reservoir portion  114 , such that an outer side  142  of the mouthpiece cap  140  forms an essentially continuous surface with an outer side  144  of the atomizer/liquid reservoir portion  114 . 
     The atomizer/liquid reservoir portion  114  of the exemplary embodiment of  FIG.  2    is arranged between the power supply portion  112  and the mouthpiece cap  140  in a longitudinal direction L of the e-cigarette  100 , the longitudinal direction L pointing from the mouthpiece cap  140  to the power supply portion  112 . 
       FIG.  3    shows the exemplary embodiment of  FIG.  2    in a refill state. In the refill state, the mouthpiece cap  140  is arranged in its refill position R. In the refill position R, a docking valve  146  of the e-cigarette  100  for receiving liquid to be stored in the atomizer/liquid reservoir portion  114  is exposed or uncovered by the mouthpiece cap  140 . 
     In its refill position R, the mouthpiece cap  140  is arranged at a distance to its vaping position V at least against the longitudinal direction L of the e-cigarette  100 . Hence, in the refill position R, the mouthpiece cap  140  is arranged further away from the power supply portion  112  compared to its vaping position V. 
     Optionally or additionally, the mouthpiece cap  140  may be rotated around the longitudinal direction L by a predefined angle compared to its vaping position V. In the exemplary embodiment of  FIG.  3   , the mouthpiece cap  140  is arranged further away from the power supply portion  112  and rotated around the longitudinal direction L with respect to the vaping position V shown in  FIG.  2   , in which the mouthpiece cap  140  covers the docking valve  146 , such that dirt or dust is hindered from entering the docking valve  146 . 
     The arrow MO indicates a possible movement path of the mouthpiece cap  140  between the refill position R and the vaping position V. 
     At least in the refill position R and optionally also in the vaping position V, the mouthpiece cap  140  is captively or undetachably connected to the atomizer/liquid reservoir portion  114 , such that the mouthpiece cap  140  cannot be lost. 
     In the exposed or uncovered state of the docking valve  146 , a source of liquid, exemplarily shown as a refill bottle  148 , can dock at the docking valve  146  in order to refill the e-cigarette  100 , in particular the liquid reservoir of the e-cigarette  100 . In order to dock the refill bottle  148  with the docking valve  146 , a counter docking valve  150  of the refill bottle  148  can be placed onto or inside of the docking valve  146 , e.g. essentially perpendicular to the longitudinal direction L of the e-cigarette  100 . 
       FIG.  4    shows the exemplary embodiment of  FIGS.  2  and  3   , wherein the refill bottle  148  is in a docked position D after the refill bottle  148  has been moved along a movement path for docking MD, which essentially extends perpendicularly to the longitudinal direction L. 
       FIG.  5    shows the refill bottle  148  in its docked position D. In order to refill the e-cigarette  100 , the refill bottle  148  can be squeezed, e.g. perpendicular the longitudinal direction L. Squeezing the refill bottle  148  means compressing the refill bottle  148 , or pressing opposite side walls  152 ,  154  of the refill bottle  148  together. In the docked position D, the side walls  152 ,  154  can extend essentially perpendicularly to the longitudinal direction L of the e-cigarette  100 . 
       FIG.  6    shows the exemplary embodiment of  FIGS.  2  to  5   . In order to separate the refill bottle  148  from the e-cigarette  100 , the refill bottle  148  is moved away from the e-cigarette  100  along the movement path for undocking MU. In order to release the connection in between the docking valve  146  and the counter docking valve  150 , at least the movement along the movement path for undocking MU is sufficient. Optionally, the refill bottle  148  may additionally tilted back and forth perpendicularly to the movement path for undocking MU. 
       FIG.  7    shows the exemplary embodiment of  FIGS.  2  to  6   . The mouthpiece cap  140  is shown positioned in its vaping position V. The vaping position V may differ from the refill position R along and/or around the longitudinal direction L. In the exemplary embodiment of  FIG.  7   , the mouthpiece cap  140  is moved from the refill position R to the vaping position V along the movement path MC, i.e. first around the longitudinal direction L and, then, along the longitudinal direction L. 
     The exemplary embodiment of the electronic smoking device comprising the mouthpiece cap  140  and the docking valve  146  may, as such, be advantages on its own and independent of the further features of the exemplary embodiment mentioned in the following. 
       FIG.  8    shows the exemplary embodiment of  FIGS.  2  to  7    in a cross-sectional view, wherein the cross-section extends along the longitudinal direction L of the e-cigarette  100 . 
       FIG.  9    shows an enlarged detail I of  FIG.  8   . 
       FIGS.  8  and  9    show the liquid reservoir  134  of the atomizer/liquid reservoir portion  114 . A central passage  132  of the atomizer/liquid reservoir portion  114  extends through the liquid reservoir  134  against the longitudinal direction L in order to transport atomized liquid towards an air inhalation port  136  of the atomizer/liquid reservoir portion  114 , the air inhalation port  136  opening into the mouthpiece cap  140 . The liquid reservoir  134  has a cylindrical cross-section and extends along the longitudinal direction L. The central passage  132  is arranged in the liquid reservoir  134 , such that the liquid reservoir  134  surrounds or encompasses the central passage  132  at least sectionwise or even completely perpendicular to the longitudinal direction L. 
     The atomizer/liquid reservoir portion  114  is formed with a liquid duct  156 , that is adapted to the receive liquid from the docking valve  146  and that opens into the liquid reservoir  134  at a distance A to the docking valve  146 . The liquid duct  156  essentially extends perpendicularly to the longitudinal direction L. Hence, sections of the liquid reservoir  134 , which are arranged at a distance from the docking valve  146  can receive liquid first when refilling the liquid reservoir  134 . Thus, air present in the liquid reservoir  134  before refilling the liquid reservoir  134  can escape at least along a part of the liquid reservoir  134  that is arranged at the liquid duct  156  and/or the docking valve  146 . 
     The docking valve  146  is shown with a sealing element  158  that is pressed into a sealing position, in which the sealing element  158  seals the docking valve  146 . The docking valve  146  comprises a resilient element  160  that seeks to press the sealing element  158  in the sealed position. 
     For example, the sealing element  158  has a spherical shape, e.g. the shape of a ball. The resilient element  160  is e.g. a spring and for example a coil spring. 
     The resilient element  160  in particular seeks to press the sealing element  156  perpendicular to the longitudinal direction L into its sealing position. 
     In the embodiment shown in  FIGS.  8  and  9   , the mouthpiece cap  140  is positioned in its refill position R and the counter docking valve  150  of the refill bottle  148  is docked to the docking valve  146 . The counter docking valve  150  presses the sealing element  158  out of its sealing position against the spring force of the resilient element  160 , i.e. essentially perpendicular to the longitudinal direction L. 
     The docking valve  146  is adapted to form a snap-fit connection with the counter docking valve  150  of the refill bottle  148 . For example, the docking valve  146  has a docking section, wherein the docking section comprises a convex- or a concave-shaped cross-section, thereby forming a setback or recess  162 . The counter docking valve  150  is adapted to form a snap-fit connection with the docking valve  146  of the electronic smoking device. The counter docking valve  150  for example, comprises elastic latch claws  164  that are arranged around a central axis of the counter docking valve  150 . The latch claws  164  are shown curved towards the central axis and are adapted to engage the recess  162  in the docked position D of the refill bottle  148 . 
     The embodiment of the docking valve  148  forming the recess  162  and the counter docking valve  150  with the elastic latch claws  164  is advantages on its own and in particular independent of the embodiments discussed previously and in the following. 
     The liquid duct  156  opens into the liquid reservoir  134  with an outlet orifice  166 . The outlet orifice  166  is arranged at a predetermined distance to a side wall section  168  of the liquid reservoir  134  at which the docking valve  146  is arranged. For example, the outlet orifice  166  is arranged closer to a side wall section  170  of the liquid reservoir  134  opposite to the side wall section  168 , i.e. opposite to the docking valve  146 , than to the docking valve  146 . In particular, the outlet orifice  166  opens into a section of the liquid reservoir  134  that is opposite to another section of the liquid reservoir  134  arranged at the docking valve  146 . 
     Arrow FI indicates the flow-in path of liquid  172  flowing from the refill bottle  148  into the liquid reservoir  134 . The other arrow FO indicates a flow-out path of air as it escapes out of the liquid reservoir  134  when refilling the liquid  172 . The flow-in path FI begins inside of the refill bottle  148  and extends through the counter docking valve  150 , the docking valve  146  and through the liquid duct  156  into the liquid reservoir  134 . The flow-out path FO extends through a part of the liquid reservoir  134  that surrounds the liquid duct  156  and/or is arrange at the docking valve  146  against the longitudinal direction L towards the air inhalation port  136 . Along the air inhalation port  136 , the flow-out path FO extends through the mouthpiece cap  140  outside the electronic smoking device  100 . The embodiment of the atomizer/liquid reservoir portion  114  with the liquid duct  156  and optionally with the outlet orifice  166  is advantages on its own independent of the embodiments previously and in the following. 
       FIG.  10    shows the exemplary embodiment of  FIGS.  2  to  9    in the cross-sectional view of  FIGS.  8  and  9   , wherein no refill bottle is docked with the docking valve  146 . The sealing element  158  seals the docking valve  146 , wherein the resilient element  160  presses the sealing element  158  against side walls of the docking valve  146  that delimit an inlet opening  174  of the docking valve  146 . 
       FIG.  11    shows the exemplary embodiment of  FIGS.  2  to  10    in another cross-sectional view, wherein the cross-section extends along the longitudinal direction L. The docking valve  146  points into the drawing plane of  FIG.  11   . 
     The cross-sectional plane extends along the longitudinal direction L through the central passage  132 . The liquid duct  156  extends through the central passage  132 , in particular, through a convex section  176  of the central passage  132 . The convex section  176  is formed by two passage sections  178 ,  180  that interconnect parts of the central passage  132  before and after the liquid duct  156  in the longitudinal direction L. The passage sections  178 ,  180  essentially form a passage ring through which the liquid duct  156  extends essentially perpendicular to the longitudinal direction L. The path of atomized liquid extends through the central passage  132  and through the passage sections  178 ,  180  is indicated by the arrow AP. 
     The electronic smoking device  100  and in particular the atomizer/liquid reservoir portion  114  comprises a valve  181  for releasing gas, e.g. air from the liquid reservoir  134  when refilling the liquid reservoir  134 , the valve  181  comprising a flexible sealing element  182  and essentially rigid counter sealing element  186  formed by an outer side wall section  183  of the central passage  132 . 
     The section of the central passage  132  that provides for the rigid counter sealing element  186  has a curved shape. 
     The atomizer/liquid reservoir portion  114  comprises at least one flexible sealing element  182  that rests against the outer side wall section  183  of the convex section  176  and thereby closes the flow-out path FO. When refilling the atomizer/liquid reservoir portion  114 , pressing the liquid out of the refill bottle  148  into the liquid reservoir  134  increases the pressure of air within the liquid reservoir  134 . This increased pressure is sufficient in order to replace or deform the flexible sealing element  182 , such that air can escape from the liquid reservoir  134  via the flexible sealing element  182  towards the mouthpiece cap  140 . 
     The flexible sealing element  182  can be an umbrella seal or can comprise at least one flexible sealing tongue or lip with a fixed end in the longitudinal direction L and a free end against the longitudinal direction L. 
     The mouthpiece cap  140  can comprise at least one closing element  184  that forces the flexible sealing element  182  against a rigid counter sealing element  186  provided by the convex section  176  and in particular by the outer side wall section  183 . The rigid counter sealing element  186  and the flexible sealing element  182  are shown arranged at a side of the convex section  176  that faces the mouthpiece cap  140 . 
     In the refill position R the closing element  184  is arranged at a distance to the flexible sealing element  182  against the longitudinal direction L. In the vaping position V of the mouthpiece cap  140 , the closing element  184  rests against the flexible sealing element  182  and holds the flexible element  182  against the rigid counter sealing element  186 . 
     The embodiment of the atomizer/liquid reservoir portion  114  with the flexible sealing element  182 , the closing element  184  and the rigid counter sealing element  186  as such is advantages on its own and independent of the embodiments disclosed previously and in the following. 
       FIG.  12    shows the exemplary embodiment of  FIGS.  2  to  11    in the cross-sectional view of  FIG.  10   . 
     The mouthpiece cap  140  is held in the refill position R and/or the vaping position V in a force-fit manner. For example, the mouthpiece cap  140  is held in the refill position R or in the vaping position V by a latched connection. A latch element  188 , e.g. a protrusion, is provided by an end of the closing element  184  perpendicular to the longitudinal direction L, and counter latch elements  190 ,  192 , for example latch protrusions or latch recesses, are provided by an outer side wall section  194  of the central passage  132 . The outer side wall section  194  may be the lateral surface of the central passage  132 . The counter latch element  190  that holds the mouthpiece cap  140  in the vaping position V may be provided by a latch protrusion and the counter latch element  192  that holds the mouthpiece cap  140  in the refill position R may be provided by a latch recess or a set back provides by the latch recess or a protrusion. 
     In summary, in one aspect, the electronic smoking device comprises a power supply portion comprising a power supply, and an atomizer/liquid reservoir portion comprising a refillable liquid reservoir adapted for storing liquid, and an atomizer operable when connected to the power supply to atomize liquid stored in the liquid reservoir. The atomizer/liquid reservoir portion comprises a docking valve for docking a source of liquid to be stored in the liquid reservoir. For example, the source of liquid is a refill bottle filled with liquid to be stored in the liquid reservoir. Furthermore, the atomizer/liquid reservoir portion comprises a liquid duct that is adapted to receive liquid from the docking valve and that opens into the refillable liquid reservoir at a distance to the docking valve. An advantage of this aspect may be that due to the distance between the opening of the liquid duct and the docking valve, a volume remains between the opening of the liquid duct and the docking valve that is filled as a last volume of the liquid reservoir, such that gas and in particular air can escape via this volume. 
     According to an embodiment, the liquid duct opens into the refillable liquid reservoir with an outlet orifice, wherein the outlet orifice is arranged at a predetermined distance to a side wall section of the refillable liquid reservoir at which the docking valve is arranged. According to an embodiment, the outlet orifice faces in or against a longitudinal direction of the electronic smoking device the longitudinal direction extending between two extreme ends of the electronic smoking device. 
     According to an embodiment, the outlet orifice is arranged closer to a side wall section of the refillable liquid reservoir opposite to the docking valve then to the docking valve. 
     According to an embodiment, the electronic smoking device and in particular the atomizer/liquid reservoir portion comprises a central passage that is adapted to conduct atomized liquid. According to an embodiment, the central passage extends through the refillable liquid reservoir. According to an embodiment, the electronic smoking device and in particular the atomizer/liquid reservoir portion comprises a valve for releasing gas from the refillable liquid reservoir when refilling the refillable liquid reservoir, the valve comprising a flexible sealing element and essentially rigid counter sealing element formed by an outer side wall section of the central passage. Thus, a possible advantage of this embodiment may be that as the central passage may be used as a part of the valve, the valve does not require much space, wherein air replaced by the liquid in the liquid reservoir can be released easily. 
     According to an embodiment, the section of the central passage that provides for the rigid counter sealing element has a curved shape. Due to the curved shape, an advantage may be that the flexible sealing element can rest against the rigid counter sealing element at a larger surface area, thereby improving sealing features of the valve. 
     According to an embodiment, the liquid duct extends essentially perpendicular to and through the central passage at a convex section of the central passage. According to an embodiment, the convex section provides for the counter sealing element. Thus, an advantage of this embodiment may be that the liquid from the source of liquid can easily flow to a volume of the liquid reservoir at a distance to the liquid duct, wherein the total cross-section of the central passage is essentially not affected or decreased by the liquid duct. Another advantage of this embodiment may be that the convex section provides the counter sealing element with an essentially symmetric and in particular rotation-symmetric form around the longitudinal direction of the electronic smoking device, thereby facilitating producibility and usability of the electronic smoking device. 
     According to an embodiment, the electronic smoking device and in particular the atomizer/liquid reservoir portion comprises a mouthpiece cap for providing atomized liquid to a user. According to an embodiment, the mouthpiece cap comprises a refill position and a vaping position. According to an embodiment, in the vaping position, the mouthpiece cap is closer to an opposite end of the electronic smoking device and in particular of the atomizer/liquid reservoir portion than in the refill position. Alternatively or additionally, according to an embodiment, in the vaping position, the mouthpiece cap is rotated around the longitudinal axis of the electronic smoking device and in particular of the atomizer/liquid reservoir portion by a predetermined angle compared to the refill position. According to an embodiment, the predetermined angle may be up to 45 degrees, up to 90 degrees, up to 135 degrees, up to 180 degrees or even up to 270 degrees. 
     According to an embodiment, the docking valve is covered by the mouthpiece cap in the vaping position. An advantage of this embodiment may be that particles like dust cannot enter and affect the docking valve when the electronic smoking device and in particular the atomizer/liquid reservoir portion is in use. According to an embodiment, the docking valve is accessible, i.e. not covered, when the mouthpiece cap is in the refill position. Thus, an advantage of this embodiment may be that the docking valve can easily be accessed and docked to the source of liquid when a refill of liquid is required. 
     According to an embodiment, the mouthpiece cap is captively or undetachably affixed to the electronic smoking device and in particular to the atomizer/liquid reservoir portion at least in the refill position and optionally or additionally in the vaping position. Hence, an advantage of this embodiment may be that the mouthpiece cap cannot be lost when the electronic smoking device and in particular the atomizer/liquid reservoir portion is in use or is refilled. 
     According to an embodiment, the mouthpiece cap comprises a closing element that forces the flexible sealing element against the rigid sealing element when the mouthpiece cap is in the vaping position. An advantage of this embodiment may be that no liquid can flow through the valve for releasing gas from the refillable liquid reservoir when the mouthpiece cap is in the vaping position, hence, when the electronic smoking device and in particular the atomizer/liquid reservoir portion are not being refilled, i.e. in use or retained. 
     According to an embodiment, the closing element is arranged at a distance to the flexible sealing element when the mouthpiece cap is in the refill position. An advantage of this embodiment may be that gas can easily escape the liquid reservoir when refilling the liquid reservoir. 
     According to an embodiment, the mouthpiece cap is held in the refill position and/or in the vaping position in a force-fit manner, for example by a latch connection. An advantage of this embodiment may be that the mouthpiece cap cannot inadvertently change its position, thereby affecting refilling or causing liquid spills. 
     According to an embodiment, the mouthpiece cap is held in the vaping position by a latch-connection. 
     According to an embodiment, a latch element of the latch-connection is provided by the closing element and at least one counter latch element is provided by an outer side wall section of the central passage. An advantage of this embodiment may be that the latch connection requires less space. 
     According to an embodiment, the docking valve is adapted to form a snap-fit connection with a counter docking valve of a source of liquid, e.g. of a refill bottle. An advantage of this embodiment may be that a snap-fit connection between the source of liquid and the docking valve cannot be opened inadvertently. Another possible advantage of this embodiment may be that due to the snap-fit connection, a user refilling the electronic smoking device and in particular the atomizer/liquid reservoir portion gets a tactile response when the connection between the source of liquid and the docking valve is completed. 
     According to an embodiment, the docking valve has a docking section, the docking section comprising a convex or a concave shape. An advantage of this embodiment may be that the convex or concave shape provides for the snap-fit connection with a low amount of space. 
     In summary, in another aspect, a refill bottle for refilling an electronic smoking device and in particular an atomizer/liquid reservoir portion with a docking valve for docking the refill bottle is provided. According to an embodiment, the refill bottle comprises a counter docking valve, the counter docking valve being adapted to form a snap-fit connection with the docking valve of the electronic smoking device and in particular with the atomizer/liquid reservoir portion described previously. 
     According to an embodiment, the counter docking valve comprises elastic latch claws that are arranged around a central axis of the counter docking valve. An advantage of this embodiment may be that the elastic latch claws provide for the snap-fit connection with a low requirement for space and at low cost. 
     According to an embodiment, the latch claws curve towards or away from the central axis. An advantage of this embodiment may be that latch claws curving towards the central axis can be placed onto the docking valve, which can thus be received in the counter docking valve, thereby easily providing for the snap-fit connection. Another possible advantage of this embodiment may be that latch claws curving away from the central axis can be easily introduced into the docking valve, thereby providing for the snap-fit connection at low costs and with a low space requirement. 
     In yet another aspect, an atomizer/liquid reservoir portion comprising a refillable liquid reservoir adapted for restoring liquid, and an atomizer operable when connected to a power supply for an electronic smoking device to atomize liquid stored in the liquid reservoir is provided. According to an embodiment, the atomizer/liquid reservoir portion comprises a docking valve for docking a source of liquid to be stored in the liquid reservoir. According to an embodiment, the atomizer/liquid reservoir portion comprises a liquid duct that is adapted to receive liquid from the docking valve and that opens into the refillable liquid reservoir at a distance to the docking valve. 
     According to an embodiment, the liquid duct opens into the refillable liquid reservoir with an outlet orifice, wherein the outlet orifice is arranged at a predetermined distance to a side wall section of the refillable liquid reservoir at which the docking valve is arranged. According to an embodiment, the outlet orifice faces in or against a longitudinal direction of the atomizer/liquid reservoir portion the longitudinal direction extending between two extreme ends of the atomizer/liquid reservoir portion. 
     According to an embodiment, the outlet orifice is arranged closer to a side wall section of the refillable liquid reservoir opposite to the docking valve then to the docking valve. 
     According to an embodiment, the atomizer/liquid reservoir portion comprises a central passage that is adapted to conduct atomized liquid. According to an embodiment, the central passage extends through the refillable liquid reservoir. According to an embodiment, the atomizer/liquid reservoir portion comprises a valve for releasing gas from the refillable liquid reservoir when refilling the refillable liquid reservoir, the valve comprising a flexible sealing element and essentially rigid counter sealing element formed by an outer side wall section of the central passage. Thus, a possible advantage of this embodiment may be that as the central passage may be used as a part of the valve, the valve does not require much space, wherein air replaced by the liquid in the liquid reservoir can be released easily. 
     According to an embodiment, the section of the central passage that provides for the rigid counter sealing element has a curved shape. Due to the curved shape, an advantage may be that the flexible sealing element can rest against the rigid counter sealing element at a larger surface area, thereby improving sealing features of the valve. 
     According to an embodiment, the liquid duct extends essentially perpendicular to and through the central passage at a convex section of the central passage. According to an embodiment, the convex section provides for the counter sealing element. Thus, an advantage of this embodiment may be that the liquid from the source of liquid can easily flow to a volume of the liquid reservoir at a distance to the liquid duct, wherein the total cross-section of the central passage is essentially not affected or decreased by the liquid duct. Another advantage of this embodiment may be that the convex section provides the counter sealing element with an essentially symmetric and in particular rotation-symmetric form around the longitudinal direction of the atomizer/liquid reservoir portion, thereby facilitating producibility and usability of the atomizer/liquid reservoir portion. 
     According to an embodiment, the atomizer/liquid reservoir portion comprises a mouthpiece cap for providing atomized liquid to a user. According to an embodiment, the mouthpiece cap comprises a refill position and a vaping position. According to an embodiment, in the vaping position, the mouthpiece cap is closer to an opposite end of the atomizer/liquid reservoir portion than in the refill position. Alternatively or additionally, according to an embodiment, in the vaping position, the mouthpiece cap is rotated around the longitudinal axis of the atomizer/liquid reservoir portion by a predetermined angle compared to the refill position. According to an embodiment, the predetermined angle may be up to 45 degrees, up to 90 degrees, up to 135 degrees, up to 180 degrees or even up to 270 degrees. 
     According to an embodiment, the docking valve is covered by the mouthpiece cap in the vaping position. An advantage of this embodiment may be that particles like dust cannot enter and affect the docking valve when the atomizer/liquid reservoir portion is in use. According to an embodiment, the docking valve is accessible, i.e. not covered, when the mouthpiece cap is in the refill position. Thus, an advantage of this embodiment may be that the docking valve can easily be accessed and docked to the source of liquid when a refill of liquid is required. 
     According to an embodiment, the mouthpiece cap is captively or undetachably affixed to the atomizer/liquid reservoir portion at least in the refill position and optionally or additionally in the vaping position. Hence, an advantage of this embodiment may be that the mouthpiece cap cannot be lost when the atomizer/liquid reservoir portion is in use or is refilled. 
     According to an embodiment, the mouthpiece cap comprises a closing element that forces the flexible sealing element against the rigid sealing element when the mouthpiece cap is in the vaping position. An advantage of this embodiment may be that no liquid can flow through the valve for releasing gas from the refillable liquid reservoir when the mouthpiece cap is in the vaping position, hence, when the atomizer/liquid reservoir portion are not being refilled, i.e. in use or retained. 
     According to an embodiment, the closing element is arranged at a distance to the flexible sealing element when the mouthpiece cap is in the refill position. An advantage of this embodiment may be that gas can easily escape the liquid reservoir when refilling the liquid reservoir. 
     According to an embodiment, the mouthpiece cap is held in the refill position and/or in the vaping position in a force-fit manner, for example by a latch connection. An advantage of this embodiment may be that the mouthpiece cap cannot inadvertently change its position, thereby affecting refilling or causing liquid spills. 
     According to an embodiment, the mouthpiece cap is held in the vaping position by a latch-connection. 
     According to an embodiment, a latch element of the latch-connection is provided by the closing element and at least one counter latch element is provided by an outer wall section of the central passage. An advantage of this embodiment may be that the latch connection requires less space. 
     According to an embodiment, the docking valve is adapted to form a snap-fit connection with a counter docking valve of a source of liquid, e.g. of a refill bottle. An advantage of this embodiment may be that a snap-fit connection between the source of liquid and the docking valve cannot be opened inadvertently. Another possible advantage of this embodiment may be that due to the snap-fit connection, a user refilling the atomizer/liquid reservoir portion gets a tactile response when the connection between the source of liquid and the docking valve is completed. 
     According to an embodiment, the docking valve has a docking section, the docking section comprising a convex or a concave shape. An advantage of this embodiment may be that the convex or concave shape provides for the snap-fit connection with a low amount of space. 
     While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims. 
     LIST OF REFERENCE SIGNS 
     
         
           10 ,  100  electronic smoking device 
           12 ,  112  power supply portion 
           14 ,  114  atomizer/liquid reservoir portion 
           16  end cap 
           18  battery 
           20  light-emitting diode (LED) 
           22  control electronics 
           24  airflow sensor 
           26 ,  126  atomizer 
           28  heating coil 
           30  wick 
           32 ,  132  central passage 
           34 ,  134  liquid reservoir 
           36 ,  136  air inhalation port 
           38 ,  138  air inlets 
           140  mouthpiece cap 
           142  outer side of mouthpiece cap 
           144  outer side of atomizer/liquid reservoir portion 
           146  docking valve 
           148  refill bottle 
           150  counter docking valve 
           152 ,  154  side walls of refill bottle 
           156  liquid duct 
           158  sealing element 
           160  resilient element 
           162  recess 
           164  elastic latch claws 
           166  outlet orifice of liquid duct 
           168  side wall section of liquid reservoir with docking valve 
           170  side wall section of liquid reservoir opposite to docking valve 
           172  liquid 
           174  inlet opening of docking valve 
           176  convex section of central passage 
           178 ,  180  passage section 
           181  valve 
           182  flexible sealing element 
           183  outer side wall section of convex section of central passage 
           184  closing element 
           186  rigid counter sealing element 
           188  latch element 
           190 ,  192  counter latch element 
           194  outer side wall section of central passage with counter latch element 
         A distance 
         AP path of atomized liquid 
         D docked position 
         FI flow-in path 
         FO flow-out path 
         L longitudinal direction 
         MC movement path from vaping to refill position 
         MD movement path for docking 
         MO movement path from refill to vaping position 
         MU movement path for undocking 
         R refill position 
         V vaping position