Patent Publication Number: US-9891086-B2

Title: Fluid dispenser

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 13/563,096, filed Jul. 31, 2012 which claims the benefit under 35 U.S.C. § 119(e) of U.S. provisional patent application Ser. No. 61/534,000, filed Sep. 13, 2011, and priority under 35 U.S.C. § 119(a)-(d) of French Patent Application No. 11 57046, filed Aug. 1, 2011. The entire disclosures of the prior applications are considered part of the disclosure of the accompanying continuation application, and are hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a fluid dispenser that makes it possible to apply a fluid to a target surface by means of an applicator. Fluid is transferred from the applicator that forms an integral part of the fluid dispenser, by putting the applicator into contact with the target surface, which surface may be the skin of a user of the dispenser, for example. The present invention applies more particularly to applicator dispensers for applying fluids of low viscosity, i.e. of viscosities that are close or identical to the viscosity of water, e.g. such as perfumes, lotions, etc. 
     BACKGROUND OF THE INVENTION 
     In the prior art, such applicator dispensers are already known for taking fluid from a fluid reservoir, the applicator is then removed from the reservoir so as to come into contact with the target surface so as to apply fluid thereto. The fluid applicator may retain the fluid by any physical principle, e.g. such as capillarity. By way of example, document FR 2 924 696 is known which describes a fluid dispenser comprising: a reservoir; a metering chamber of variable volume that defines an extraction zone; a dip tube that connects the reservoir to the metering chamber; suction means for sucking fluid from the reservoir into the chamber through the dip tube; and a fluid applicator that is suitable for taking the fluid sucked into the extraction zone of the chamber. In greater detail, the dip tube extends inside the metering chamber, and more particularly inside the extraction zone, such that, at rest, when the metering chamber is at its minimum volume, the extension of the dip tube is driven fully into the extraction zone. In that document, the extraction zone is in the form of a blind tube that is open at its bottom end and closed at its top end. In addition, the bottom end defines a piston lip in leaktight sliding contact with the inside of a cylinder that is mounted in stationary manner on the reservoir. In that way, when the dispenser is at rest, the extension of the dip tube extends inside the blind tube that forms the extraction zone, which in turn is disposed inside the slide cylinder, which in turn is disposed inside the reservoir. That results in four elements being disposed in coaxial manner. However, one of the preferred embodiments of that dispenser is to opt for the various component elements to be made of transparent plastics material, so that the user can see the internal structure of the dispenser. That gives the dispenser a certain glassy look that makes it more attractive in appearance. But, the presence of the extension of the dip tube inside the extraction zone significantly degrades the transparent effect, as a result of the multiplicity of coaxial elements. In addition, from a more functional point of view, the extension of the dip tube should be made with a wall thickness that is relatively thick, so as to impart a certain stiffness thereto. Such stiffness is necessary given that the tube that forms the extraction zone must, on each actuation, be engaged around the extension. As a result of the relatively large diameter of the extension of the dip tube, the tube of the extraction zone must be made with a relatively large diameter, and this degrades firstly attractiveness, and secondly the capacity to retain fluid inside the extraction zone by capillarity. 
     BRIEF SUMMARY OF THE INVENTION 
     An object of the present invention is to remedy the above-mentioned drawbacks by defining another principle for filling the extraction zone, which principle also imparts a more attractive appearance. 
     To achieve this object, the present invention proposes a fluid dispenser comprising: a fluid reservoir containing fluid; a fluid suction chamber of variable volume that defines an extraction and application space; a dip tube that connects the reservoir to the chamber at an injection orifice that defines an injection axis; and suction means for sucking, during a suction stage, fluid from the reservoir into the chamber through the injection orifice; the dispenser being characterized in that the extraction and application space has a constant volume, the injection orifice being situated a little way inside or outside the extraction and application space, such that the fluid is injected in the form of an axial jet into the extraction and application space and fills it, at least in part, without the injection orifice penetrating into the space. Advantageously, the extraction and application space is situated on the injection axis, the space defining an open end that is close to the injection orifice, and a closed end that is remote from the injection orifice, the space communicating with the remainder of the chamber and the injection orifice via the open end. The injection orifice is situated outside the space or penetrates over a very short distance into the space, always being positioned in the proximity of the open end and at a distance from the closed end. Advantageously, the space is formed by a blind tube of constant volume that is secured to a grip member that is movable along the injection axis. Advantageously, the suction chamber includes a shell that, at its bottom end, defines the injection orifice, the tube being disposed in the shell. Advantageously, the shell defines a sealing slide-cylinder in which there slides a piston that is secured to the grip member in such a manner as to create suction in the chamber by pulling axially on the grip member. Advantageously, the increase in volume of the chamber during the suction stage is slightly greater than the volume of the space. Preferably, the tube and the shell are transparent, such that the fluid that fills the space is visible through the tube and the shell. 
     Thus, the dispenser of the invention differs from the dispenser in document FR 2 924 696 mainly by the fact that the extraction and application space contains only fluid and/or air, and never any other element of the dispenser, given that the injection orifice penetrates little, if at all, inside the extraction and application space. This particular structure has been determined in empirical manner, and the dispenser was observed to operate well without even understanding the physical principle. It was only after in depth studies that it was observed that the extraction and application space is filled, not by suction as in the prior-art document, but rather by injecting a jet under pressure through the injection orifice into the extraction and application space. It should not be forgotten that the extraction and application space includes an end that is closed in such a manner as to define a blind space: thus, the fluid cannot be sucked through the extraction and application space. When the dispenser is handled, the filling of the extraction and application space seems surprising and mysterious, since the physical principle on which filling is based is not obvious. Tests on consumers have shown that they find the handling of the dispenser is somewhat mysterious, since, à priori, the principle on which its extraction and application space is filled is incomprehensible. And the mystery is made deeper still since the tube and the shell are transparent, as is the fluid reservoir. Thus, when the extraction and application space is visible, the user may watch the extraction and application space being filled, but without being able to observe the axial jet of fluid coming from the injection orifice, since the jet is small and rapid. 
     By means of this particular structure in which no element of the dispenser really penetrates inside the extraction and application space, the space may present a configuration that is substantially axially cylindrical, defining an inside diameter of about 3 millimeters (mm). In addition, the space presents an axial height of about 1 centimeter (cm). 
     In order to accentuate the transparency of the tube, said tube may include a free bottom edge that is rounded towards the inside, and that defines the open end of the space. The shell may also be formed with a rounded bottom end, such that no sharp edge is visible at this location. Only the open end of the extraction and application space defines a sharp edge at which the fluid forms a meniscus. 
     According to an advantageous practical characteristic, at the start of the suction stage, the open end of the space is situated axially just above the injection orifice. 
     Preferably, the injection orifice may present a diameter of about 1 mm. 
     In another aspect of the invention, the dip tube is invisible in the fluid. Thus, the user cannot even see the dip tube connecting the reservoir to the extraction and application space. 
     A principle of the invention resides in the fact that the extraction and application space is filled by means of a jet of fluid under pressure, and not only by means of suction. This makes it possible firstly to leave the space free of any other part of the dispenser, and secondly to increase the stiffness of the dispenser. From an appearance point of view, attractiveness is improved considerably, given that the extraction and application space is filled only with fluid and/or air. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is described more fully below with reference to the accompanying drawings, which show an embodiment of the present invention by way of non-limiting example. 
       In the figures: 
         FIG. 1 a    is a vertical-section view through a fluid dispenser in an embodiment of the invention; 
         FIG. 1 b    is a variant of the  FIG. 1 a    embodiment; 
         FIGS. 2, 3, 4, 5, 6, and 7  are views similar to the  FIG. 1 a    view showing the various steps of a complete operating cycle of the dispenser. 
     
    
    
     DETAILED DESCRIPTION 
     Reference is made firstly to  FIG. 1 a    in order to explain in detail the structure of the dispenser in an embodiment of the invention. The fluid dispenser essentially comprises three component elements, namely a reservoir  1 , a ring  2 , and an applicator member that also serves as a removable stopper element. 
     The reservoir  1  may present a design that is very simple, namely in the form of a cylindrical tube that is advantageously circularly cylindrical and that presents a closed bottom and a neck  11  that defines an opening. The reservoir  1  may be made of any material, e.g. glass, appropriate plastics material, metal, etc. The reservoir is preferably transparent, at least at its neck  11 . The reservoir preferably presents capacity that is small, of the order of a few milliliters. It is for filling, at least in part, with fluid P. 
     The ring  2  is preferably made of plastics material, e.g. by injection molding. The ring  2  is circularly symmetrical about a central axis X that is also the axis of the reservoir  1 . The ring  2  includes a fastener skirt  21  for coming into engagement around the neck  11  of the reservoir in permanent and leaktight manner. The fastener skirt  21  may present profiles for coming to be housed below an annular reinforcement of the neck  11 . In a variant that is not shown, the skirt  21  may present an internal thread for co-operating with an external thread that is formed by the neck  11 . Other fastening principles may also be envisaged. The ring  2  also includes an annular disk  22  that is for flattening an annular neck gasket  4  against the annular edge of the neck  11 . For appearance purposes, the skirt  21  and the disk  22  may be covered with a covering hoop  3  that advantageously masks the ring  2  completely. By way of example, the hoop  3  may be made of metal. At the inner periphery of the disk  22 , the ring  2  is extended axially upwards by a threaded section  23 . The ring  2  is thus extended once again downwards, defining a sealing slide-cylinder  25  that is disposed in coaxial manner inside the threaded section  23 . At the junction between the threaded section  23  and the slide cylinder  25 , the ring  2  forms one or more vent holes  24 . The ring  2  is extended further downwards substantially in register with the slide cylinder  25 , forming a shell  26  that extends inside the neck  11 . The shell  26  presents a main section that is substantially circularly cylindrical, and a bottom portion that is rounded in the shape of a dome. At its lowest point, the shell forms an engagement section  28  in which there is engaged a dip tube  5  that extends inside the reservoir  1  into the proximity of its bottom wall (not shown). The dip tube communicates with the inside of the shell  26  through an injection orifice  27  that is formed at the low point of the shell  26  inside the engagement section  28 . The size of the injection orifice may be of millimeter order. 
     The ring  2  may be made as a single part, or, in a variant, by assembling a plurality of separate parts. The shell  26  may be a distinct part that may be made of a transparent plastics material. 
     The applicator member of the invention is made by assembling together three component elements, namely a cap  6 , a tube  7 , and a grip member  8 . The three parts are assembled together in permanent manner so as to constitute a single part. Without going beyond the ambit of the invention, the cap  6  may be made integrally with the tube  7  or with the grip member  8 . Using three assembled-together parts satisfies technical criteria for ease of molding and of assembly, and also criteria for attractiveness. It is also possible to make the applicator member as a single part. 
     The cap  6  is a part, preferably made by injection-molding plastics material, that is circularly symmetrical about the axis X, as is the ring  2 . The cap  6  includes a bushing  63  that is internally threaded and that is for coming into engagement with the threaded section  23  of the ring  2 . Thus, the bushing  63  may be screwed on or off the ring  2 . A hard point at the end of screw-fastening makes it possible to indicate to the user that screw-fastening has been fully achieved. The cap  6  also defines a vent lip  64  that is for interrupting the passage between the vent holes  24  and the outside. The lip may also be replaced by a gasket. The cap  6  also defines a piston  65  that is for sliding in leaktight manner inside the slide cylinder  25  of the ring  2 . Thus, when the cap  6  is screwed on or off, the piston  65  slides in leaktight manner in the cylinder  25 . Finally, the cap  6  defines a stopper  67  that is engaged in the tube  7 , as described below. When the cap  6  is screwed tight onto the ring  2 , the vent lip  64  prevents any communication between the vent holes  24  and the outside. However, when the cap  6  is unscrewed from the ring  2 , the vent lip  64  is no longer in contact with the ring  2 , and the vent holes  24  find a passage to the outside between the threaded section  23  and the threaded bushing  63 . Given that the vent holes  24  are in direct communication with the inside of the reservoir  1 , it is possible to vent the reservoir when the cap  6  is unscrewed from the ring  2 . However, when the cap  6  is screwed tight onto the ring  2 , the inside of the reservoir  1  is isolated from the outside. 
     The tube  7  may be made by injection molding a plastics material, preferably a transparent plastics material. It may also be made of metal (to feel cold), glass, ceramic, etc. The tube  7  defines a bottom section  71  and a top section  75 , and presents an internal through passage that is closed in the top section  75  by the stopper  67  of the cap  6 . In its bottom section  71 , the tube  7  defines an extraction and application space  70 . The space  70  presents a closed top end  74  that is closed by the stopper  67 , and an open bottom end  73 , so that the its volume is defined and constant. It is also possible to define the space  70  as a blind housing that is closed at its top end  74  and open at its bottom end  73 . The tube  7  is secured to the cap  6  by engaging its top section  75  in the piston  65 , and by engaging the stopper  67  in its through passage. The bottom portion  71  of the tube, inside which the extraction and application space  70  is formed, extends freely and axially downwards, projecting below the cap  6 . It should be observed that the outside wall  72  of the bottom section  71  is rounded, such that the only sharp edge defined at this level is the edge that defines the open bottom end  73  of the space  70 . The extraction and application space  70  may present the following dimensions: 3 mm in diameter and 10 mm in height. 
     It should be observed that the bottom section  71  of the tube  7  is engaged inside the shell  26  of the ring  2 , defining shapes that are substantially complementary. A metering chamber C of variable volume is thus defined between the shell  26  and the tube  7 , with said volume varying as the cap  6  is screwed on and off the ring  2 . The metering chamber C is closed at its top end by the leaktight contact defined between the piston  65  and the slide cylinder  25 . At its bottom end, the metering chamber C communicates directly with the reservoir  1  through the injection orifice  27  and the dip tube  5 . The extraction and application space  70  forms an integral part of the metering chamber C and constitutes a constant-volume portion thereof. It can also be said that the variable-volume portion of the metering chamber C is constituted by everything that is situated outside the space  70 . 
     In particular, it should be observed that no component element of the dispenser penetrates into the space  70 . Its open end  73  is situated just above the injection orifice  27 . The way in which the space  70  is filled with fluid during the removal of the applicator member is described below. 
     Finally, the grip member  8  is fastened on the cap  6  by means of a collar  86  that becomes engaged in permanent manner around the threaded bushing  63 . The grip member  8  includes a grip head  81  via which the user may hold the grip member. By exerting rotary torque on the grip head  81 , the cap  6  is turned so as to screw the ring  2  on/off. 
       FIG. 1 b    shows a slight variation of the  FIG. 1 a    embodiment, in which the injection orifice  27  is formed at the top end of a small extension tube  28   a  that projects into the chamber C and slightly penetrates into the space  70 . However, it should be observed that the injection orifice  27  is nevertheless situated at the open end  73  of the space  70 . In addition, when the fluid is injected into the space  70  ( FIG. 4 ), the injection orifice  27  has already been removed from the space  70  and is at a distance from its open end  73 . The jet of fluid has to pass through a portion of the chamber C before reaching the space  70 . 
     A complete operating cycle is described below with reference to  FIGS. 2 to 7 . Starting from  FIG. 2  that shows the dispenser in the same state as in  FIG. 1 a   , when the user unscrews the grip member  8  by holding the reservoir still, the piston  65  slides in leaktight manner inside the cylinder  25  to provide a means for sucking. This relative movement between the piston and the ring  2  has the effect of increasing the working volume of the metering chamber C, thereby creating suction in the chamber C and the dip tube  5 : this is shown in  FIG. 3  by the gray zones. By continuing to remove the applicator member from the ring  2 , fluid P originating in the reservoir  1  is sucked through the dip tube  5  and the injection orifice  27 : this is shown in  FIG. 4  which shows an axial jet of fluid P under pressure being injected into the extraction and application space  70  through the chamber C. The space is moving away from the injection orifice, but the jet is powerful enough to penetrate deep into the space. At this moment, only the space  70  receives fluid.  FIG. 5  shows the dispenser just before the piston ceases to be in leaktight sliding contact with the cylinder  25 : the chamber C is thus still under suction (gray zones). The space  70  is filled with fluid P, except possibly for a small air bubble B that may form in its top portion. It can also be seen that a small quantity of fluid P is present in the bottom portion of the shell  26 . When the applicator member is removed completely from the ring, as visible in  FIG. 6 , the fluid P that has been injected into the space  70  is retained by capillarity: a meniscus is formed at the open bottom end  73  of the space  70 . The small air bubble B floats in the space  70 . A small quantity of fluid P is still present in the bottom portion of the shell  26 . 
     Once the fluid has been spread over the target surface by means of the tube  7 , and the space  70  has thus been emptied, the piston  65  is once again inserted into the cylinder  25 , thereby reforming the metering chamber C, isolating it from the outside. Driving the piston  65  into the cylinder  25  causes pressure to be increased in the chamber C by decreasing its working volume. The small quantity of fluid P remaining in the chamber C is forced to flow through the injection orifice  27  and the dip tube  5 , into the reservoir  1 . Thus, there is no fluid in the chamber C; this is visible in  FIG. 7 . The dip tube  5  is even emptied of fluid in the rest position. Thus, the fluid stored in the reservoir is not in direct contact with the outside air. The ring  2  forms a first barrier offering a single outlet passage through the dip tube. In addition, the applicator member closes this passage to the outside by forming a metering chamber of minimum volume in the rest position. It should thus be observed that the air that is held captive in the dispenser when the piston  65  is once again in leaktight sliding contact in its cylinder  25  may escape through the vent holes  24  (arrow A) until the vent lip  64  comes to interrupt the passage on the cap being screwed on tight. The dispenser is thus once again in the  FIG. 2  state. 
     By making the shell  26  and the tube  7  out of a transparent plastics material, the user may observe the extraction and application space being filled without understanding how it is filled, where filling is based on injection and not only on suction. This gives the dispenser an element of mystery that contributes to improving its image.