Abstract:
A fluid dispenser nozzle including a resilient sealing lip fitted on a substantially rigid support, the sealing lip being adapted to bear in leaktight manner against a shutter member belonging to the support that also includes a fastener member connected to the shutter member via a movable connection, the fastener member carrying the sealing lip. The movable connection is adapted to enable the shutter member to be moved from a first position in which the shutter member is spaced apart from the sealing lip to a second position in which the shutter member bears against the sealing lip and elastically deforms the sealing lip.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This is a 35 USC §371 National Stage Application of International Patent Application No. PCT/FR2006/002864 filed on Dec. 22, 2006, which claims priority under the Paris Convention to French Patent Application No. FR 06 00007, filed on Jan. 2, 2006. 
   FIELD OF THE DISCLOSURE 
   The present invention relates to fluid dispenser nozzles, to dispenser devices including such nozzles, and to methods of fabricating such nozzles. 
   BACKGROUND OF THE DISCLOSURE 
   More particularly, the invention relates to a fluid dispenser nozzle comprising a resilient sealing lip fitted on a substantially rigid support, the sealing lip being adapted to press in leaktight manner against a shutter member belonging to the support, the sealing lip being pressed elastically against a free end of said shutter member. 
   Document WO-A-00 26007 describes an example of such a dispenser nozzle, in which the support comprises a central core having the sealing lip bearing thereagainst, which sealing lip is overmolded onto the core and surrounds said core almost completely. 
   The dispenser nozzle described in that document presents the following drawbacks:
         if the sealing lip adheres accidentally to the core during overmolding, then the nozzle does not operate; and   it is not guaranteed that the sealing lip bears in leaktight manner against the core, given that the lip bears without prestress and given the possibility of shrinkage phenomena occurring during cooling of the nozzle after molding.       

   SUMMARY OF THE DISCLOSURE 
   A particular object of the present invention is to mitigate those drawbacks. 
   To this end, according to the invention, a dispenser nozzle of the kind in question is characterized:
         in that the support further comprises a fastener member connected to the shutter member via a movable connection, the fastener member carrying the sealing lip, the fastener member being annular and extending along a central axis between an inside end and an outside end, the shutter member extending axially inside the fastener member to said free end, and   in that said movable connection is adapted so that the shutter member is movable from a first position in which said shutter member is spaced apart from the sealing lip, to a second position in which said shutter member bears against the sealing lip, elastically deforming said sealing lip (at least to a small extent).       

   By means of these dispositions, the sealing lip of the nozzle can be made on or secured to the fastener member while the shutter member is in its first position, such that said shutter member does not interfere with said making or securing of the sealing lip, thereby avoiding any risk of said sealing lip accidentally adhering to said shutter member. 
   Once the sealing lip is in place on the fastener member, the shutter member is moved into its second position, in such a manner that the nozzle then occupies its normal utilization configuration. The sealing lip is thus pressed elastically against the free end of the core during engagement of the support in the nozzle housing, so that there is always a certain amount of elastic prestress on the lip, thereby guaranteeing that the fluid flow passage is completely leaktight when closed. In addition, the relative positioning between the shutter member and the sealing lip is completely under control because of the movable connection, thereby further contributing to guaranteeing effective leaktight closure by the sealing lip. 
   In various embodiments of the invention, recourse may optionally also be had to one or more of the following dispositions:
         the movable connection is bistable, the first and second positions of the shutter member being stable positions;   the movable connection comprises a plurality of arms distributed angularly around the shutter member and connecting said shutter member to the fastener member, each arm extending on a slant:
           radially outwards and axially towards the inside end of the fastener member in said first position; and   radially outwards and axially towards the outside end of the fastener member in said first position;   
           the sealing lip is annular and has a periphery fastened to the fastener member and an inner annular edge bearing elastically against an annular seat formed at the free end of the shutter member, when the shutter member is in the second position;   said annular seat is substantially frustoconical and diverges towards the nozzle housing;   the free end of the shutter member further includes a stud that, when the shutter member is in the second position, fills at least in part a central hole defined by the annular inner edge of the sealing lip;   the outside end of the fastener member presents an end face facing axially outwards, and the periphery of the sealing lip is secured at least to said end face;   the fastener member includes an inner annular surface, and the periphery of the sealing lip is secured to said inner surface at least in the vicinity of the outside end of said fastener member;   the sealing lip is overmolded on the fastener member;   the fastener member is made of a thermoplastic synthetic material and the sealing lip is made of a thermoelastic material that bonds naturally to said thermoplastic material;   the fastener member is made of polybutylene terephthalate (PBT) and the sealing lip is made of liquid silicone rubber (LSR); and   the shutter member projects from the dispenser head by a distance that is shorter than the axial movement that would be necessary to cause the shutter member to pass from the second position to the first position.       

   The invention also provides a fluid dispenser device, the device comprising:
         a dispenser head including a fluid flow passage opening out into an outwardly-open nozzle housing; and   a dispenser nozzle as defined above, the fastener member being engaged in the dispenser head, and the support being engaged in said nozzle housing, the sealing lip being adapted to bear in leaktight manner against the shutter member, thereby isolating the fluid flow passage from the atmosphere so long as fluid does not arrive under pressure from said fluid flow passage.       

   Optionally, the fastener member may present an outer surface that is engaged in direct contact with the dispenser head as a tight fit in the nozzle housing. 
   Where appropriate, the dispenser head may include a bearing member that co-operates with the shutter member by coming into abutment thereagainst to prevent said shutter member from going from the second position to the first position. 
   Furthermore, the invention also provides a method of fabricating a fluid dispenser nozzle as defined above, and comprising at least the following steps: 
   a) molding the support; 
   b) fitting the sealing lip on the support; and 
   c) moving the shutter member from the first position to the second position inside the fastener member. 
   Step b) may be a step of overmolding the sealing lip, and step c) may be performed on the support while still hot, immediately after step b). 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other characteristics and advantages of the invention appear from the following description of two embodiments given as non-limiting examples and with reference to the accompanying drawings. 
     In the drawings: 
       FIG. 1  is a perspective view of an example of a dispenser device in a first embodiment of the invention; 
       FIG. 2  is a vertical section view through the dispenser head of the  FIG. 1  device; 
       FIG. 3  is a detail axial section view of the nozzle forming part of the dispenser head of  FIG. 2 ; 
       FIG. 4  is an end view of the nozzle, seen looking along arrow IV of  FIG. 3 ; 
       FIG. 5  is a view similar to  FIG. 2  showing the dispenser head without the nozzle; 
       FIGS. 6 and 7  are section views similar to  FIG. 3 , showing the nozzle respectively before and after molding of its sealing lip, the shutter member of the nozzle then being in a first position that is different from its final position; and 
       FIG. 8  is a view similar to  FIG. 2  in a second embodiment of the invention. 
   

   DETAILED DESCRIPTION 
   In the various figures, the same references are used to designate elements that are identical or similar. 
     FIG. 1  shows a fluid dispenser device  1 , e.g. for dispensing a cosmetic or the like, and in particular having a consistency that is liquid or semi-liquid. 
   The dispenser device  1  comprises a reservoir  2  containing the fluid, optionally under pressure, and a dispenser head  3  carried by reservoir  2  and provided with a nozzle  4  adapted to enable the fluid to be expelled for utilization. 
   The dispenser head  3 , shown in  FIGS. 2 and 5 , comprises a body  5  that may for example be molded as a single piece of thermoplastic synthetic material, in particular polypropylene or the like. The body  5  may, where appropriate, be covered in a decorative covering, made of metal or of some other substance. 
   The body  5  may for example include a top face  6  (slightly domed in the example described) and a substantially cylindrical skirt  7  centered on a substantially vertical axis Z. At the center of the skirt  7 , the body  5  of the head may also include a tubular wall  8  that extends downwards along the axis Z from the top face to a free end, defining an internal well  9  in which it is possible, for example, to engage a hollow actuator rod of a pump or of a valve (not shown). 
   The well  9  communicates via a fluid flow passage  10  with a nozzle housing  11  that opens to the outside along a central axis X that may, for example, be substantially perpendicular to the axis Z (the axis X could also be inclined). The nozzle housing  11  may for example be substantially circularly cylindrical in shape, centered on the axis X. At its inside end adjacent to the tubular wall  8 , the nozzle housing  11  may present at least one abutment-forming shoulder  12 , for a purpose that is described below. 
   As shown in  FIGS. 2 ,  3 , and  4 , the nozzle  4  comprises a support  13  and a sealing lip  35 . 
   The support  13  is molded as a single piece of plastics material, in particular of thermoplastic material, e.g. polybutylene terephthalate (PBT). By way of example, the support  13  may comprise a fastener member  14  and a shutter member  15  connected to the fastener member  14  via a movable mechanical connection  16 , e.g. a bistable connection. 
   The fastener member  14  may be annular in shape, and more particularly it may be in the form of a generally cylindrical sleeve centered on the axis X, extending between an inside end  17  and an outside end  18 . The cylindrical outer surface  19  of the fastener member may present an annular rib  20  in the vicinity of its inside end  17 , which rib projects radially outwards. This rib  20  may for example include a rear face  21  that converges radially inwards and towards the well  9 , and a front face  22  that is substantially perpendicular to the axis X (see  FIG. 3 ). The outside edge  18  of the fastener member  14  may present an end face  23  that is substantially perpendicular to the axis X, and in the vicinity of said end face  23 , the cylindrical inside surface  24  of the fastener member may present an enlarged angular portion  25 . 
   The shutter member  15  may be in the form of a core of plastics material presenting circular symmetry about the axis X and extending axially between a base  26  and a free end  27  that may for example present an annular seat  28  suitable for being formed in particular by a frustoconical surface, the annular seat  28  possibly being extended axially outwards by a stud  29 . 
   The bistable mechanical connection that connects the fastener member  14  to the shutter member  15  may be a toggle connection  16 , comprising a plurality of arms  30  connecting the shutter member to the fastener member. The arms  30  may be molded integrally with the shutter member and the fastener member, and the arms may be distributed angularly around the shutter member  15  (there being three arms  30  that are distributed angularly at 120° from one another in the example described). 
   The bistable connection  16  serves to allow the shutter member  15  to move between first and second stable positions comprising:
         a first position shown in  FIG. 7 , enabling the lip  14  to be molded in the manner described below: in this position, each of the arms  30  can extend in a substantially radial plane from the base  26  of the shutter member, slanting radially outwards and axially towards the outside end  18  of the fastener member, to the inside surface  24  of said shutter member; and   a second position or utilization position, as can be seen in particular in  FIG. 3 , where each arm  30  can extend in a plane that is substantially radial from the base  26  of the shutter member, radially outwards and axially towards the inside end  17  of the fastener member, to the inside surface  24  of the fastener member.       

   It should be observed that in the second position, the shutter member  15  can project from the dispenser head  3  (see  FIG. 2 ) by a distance that is shorter than the axial displacement needed to cause the bistable connection  16  to go from its second position to its first position by pressing against said shutter member from outside the head, thereby guaranteeing that the shutter member remains in place throughout the lifetime of the device. 
   As shown in  FIGS. 2 and 3 , the sealing lip  35  may be overmolded onto the end face  23  and onto the enlarged portion  25  of the inside surface of the fastener member. The sealing lip  35  may be made of an elastomer (a thermoelastic material) selected so that said sealing lip  35  adheres naturally to the material of the support  13  merely as the result of being molded thereon. By way of example, the lip  35  may be made of liquid silicone rubber (LSR). 
   In the example described herein, the sealing lip  35  is in the form of an annular body of revolution about the axis X, the periphery  31  of said sealing lip being overmolded onto the above-mentioned end face  23  and enlarged portion  25 , and the annular inside edge  32  of said sealing lip pressing resiliently against the annular seat  28  of the shutter member  15  when the shutter member is in its second position. In this position, the central hole  32  left empty in the center of the annular inside edge  32  of the sealing lip can be substantially filled by the stud  29  of the shutter member, thereby preventing any fluid stagnating and drying out in said hole between two utilizations. 
   During the process of fabricating the nozzle  4 , the support  13  is initially molded with the bistable connection  16  in its first position, as shown in  FIG. 6 . 
   Thereafter, the sealing lip  35  is molded onto the support  13 , preferably in the same mold device that was used for molding the support  13 , using a conventional dual injection method. During unmolding, the base  26  of the shutter member is pressed in the direction of arrow  34  (see  FIG. 7 ), so as to cause the shutter member  15  to pass from its first position to its second position, as shown in  FIG. 3 . The shutter member  15  then deforms the peripheral inside edge  32  of the lip elastically to a small extent, thereby providing sealing contact with elastic prestress of said lip against the above-mentioned annular seat  28 . 
   This movement of the shutter member  15  with the bistable connection  16  going between its first and second positions can be made easier by the fact that the plastics material constituting the support  13  is still hot (particularly since the thermoelastic material of the lip  35  is generally hot-molded): the arms  30  forming the bistable connection  16  are thus subjected to plastic deformation during this movement. 
   It should be observed that the mold used for molding the sealing lip  35  may include an internal insert (not shown) having a central rod that passes through the hole  33  and an enlarged head that corresponds to the inside shape of the sealing lip  35 . During unmolding, the insert is withdrawn through the central hole  33  of the sealing lip which is thus elastically expanded as the enlarged head of the insert passes therethrough. 
   After the nozzle  4  has been made in full, the support  13  is engaged as a tight fit in the nozzle housing  11 , the outside surface  19  of the fastener member  14  coming into direct contact with the body  5  of the head. During this engagement, the annular rib  20  deforms the material of the body  5  of the head locally since said material is more flexible than the material of the support  13 . This engagement movement is made easier by the slanting profile of the rear face  21  of the rib  20 . 
   When the rear end  17  of the support member  14  comes into abutment against the shoulder  12  of the housing  11 , the rib  20  becomes anchored in the material of the body  5 , thereby guaranteeing that the nozzle  4  is completely prevented from moving. 
   The above-described device operates as follows: at rest, the sealing lip  35  hermetically closes the nozzle housing  11 , the fluid flow passage  10 , and the well  9 , thereby preventing the fluid from drying out inside the dispenser head  3 . When the user presses manually on the head  3 , that moves the hollow rod of the pump or the valve mounted on the reservoir  2 , thereby causing fluid to be expelled under pressure into the well  9 , the passage  10 , and the nozzle housing  11 , such that the annular inside edge  32  of the sealing lip moves elastically away from the seat  28  of the shutter member, thereby allowing the fluid to go past. At the end of fluid expulsion, the sealing lip  35  immediately presses once more against the shutter member  15 . 
   In the second embodiment of the invention as shown in  FIG. 8 , the dispenser device is similar to the above-described device and is therefore not described in detail herein. This dispenser device differs from the above-described device by the fact that the dispenser head  3  includes a bearing member  36  that may for example be in the form of a cylindrical or conical rod extending along the axis X inside the nozzle housing  11  from the inside end of said nozzle housing to an end face  17  that is in contact with the base  26  of the shutter member  15  or that is in the vicinity thereof. The bearing member prevents the shutter member  15  from being able to pass from its second position to its first position once the nozzle is in place on the dispenser head. In addition, and where appropriate, the bearing member  36  can also serve to cause the shutter member  15  to go from its first position to its second position during assembly of the nozzle  4  with the head  3 .