Abstract:
A fluid dispenser device ( 1 ) for associating with a fluid reservoir ( 3 ), the device including at least one check valve ( 12, 2 ) that is suitable for controlling the flow of fluid through the device, the check valve comprising a seat ( 12 ), and a movable valve member ( 2 ) that defines a contact zone that is suitable for bearing against the seat ( 12 ) in leaktight manner, the device including resilient prestress means ( 23 ) that urge the valve member in leaktight contact against its seat ( 12 ) at rest, the device being characterized in that the prestress means ( 23 ) are formed integrally with the valve member.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit under 35 U.S.C. §119(e) of pending U.S. provisional patent application Ser. No. 60/874,491, filed Dec. 13, 2006, and priority under 35 U.S.C. §119(a)-(d) of French patent application No. FR-06.51614, filed May 4, 2006. 
     
     TECHNICAL FIELD 
       [0002]    The present invention relates to a fluid dispenser device for associating with a fluid reservoir, the device including at least one check valve that is suitable for controlling the flow of fluid through the device. The present invention also relates to a method of manufacturing a valve member that is insertable in a fluid dispenser device. Such a device and such a method can be used in numerous fields, such as the fields of perfumery, cosmetics, or even pharmacy, for example. 
       BACKGROUND OF THE INVENTION 
       [0003]    Various fluid dispenser devices using one or more check valves have been known of for some considerable time. In particular, mention can be made of pumps and valves. Generally, that type of dispenser device includes one or two check valves that are respectively provided at the inlet and/or at the outlet of an internal dispenser chamber. Each check valve generally comprises a seat, and a movable valve member that defines a contact zone that is suitable for bearing selectively against the seat in leaktight manner, thereby controlling the flow of fluid at the inlet and/or at the outlet of the dispenser chamber. This is valid for pumps and valves, and also applies to other dispenser devices that use one or more check valves to control the flow of fluid. 
         [0004]    In the prior art, it is also known to urge the valve member against its seat by resilient prestress means that can be implemented in a wide variety of forms. By way of example, the prestress means can be a metal spring that presses the valve member against its seat. The resilient prestress means can also be made of plastics material and can be fitted on the valve member so as to urge it towards its seat. The advantage of the resilient prestress means is that the check valve closes more quickly, i.e. the valve member returns more quickly against its seat. This is particularly advantageous when the fluid is of high viscosity and tends to support the valve member. In addition, the resilient prestress means can be used to urge the valve member against its seat even while the check valve is at rest. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    An object of the present invention is to improve prior-art prestressed check valves by defining a check valve that is easier to make and that is easier to assemble, while guaranteeing that the check valve operates well and is leaktight. 
         [0006]    To do this, the present invention proposes a fluid dispenser device for associating with a fluid reservoir, the device including at least one check valve that is suitable for controlling the flow of fluid through the device, the check valve comprising a seat, and a movable valve member that defines a contact zone that is suitable for bearing against the seat in leaktight manner, the device including resilient prestress means that urge the valve member in leaktight contact against its seat at rest, the device being characterized in that the prestress means are formed integrally with the valve member. The valve member is thus automatically prestressed as soon as it is put into place on its seat. There is no need for an additional part or element to be fitted on the valve member or on the seat in order to provide the resilient prestress function. 
         [0007]    The prestress means advantageously bear against an abutment surface that is secured to the seat. The seat is advantageously situated between the contact zone and the abutment surface. The seat and the abutment surface are preferably situated between the contact zone and the prestress means. The valve member is thus held captive by the seat and by the abutment surface that limits its displacement in both directions. While the valve member is moving away from its seat, the prestress means press even harder against the abutment surface, thereby tending to return the valve member against its seat. 
         [0008]    In a practical embodiment, the prestress means comprise resilient tabs having free ends that are engaged with the abutment surface. The tabs are advantageously separated by slots that define flow passages for the fluid. The resilient prestress function is thus provided by the resilient deformation of the tabs having free ends that bear under the seat against the abutment surface. 
         [0009]    According to another advantageous characteristic, the prestress means are prestressed against the abutment surface, while the valve member is resting against its seat. Said prestress ensures that the check valve is perfectly leaktight even while it is at rest. This can be achieved with resilient tabs having free ends that press a little against the abutment surface even while the check valve is closed. 
         [0010]    In another aspect of the invention, the dispenser device includes a body forming an inlet duct for communicating with the reservoir, the duct having a fluid inlet and a fluid outlet, the seat being formed at the outlet from the inlet duct, the duct also forming an inner shoulder that faces towards the inlet of the duct, the shoulder forming said abutment surface, the seat and the shoulder facing in diverging directions. In this embodiment, the valve member is held captive in the inlet duct, and can only be displaced in very limited manner against the resilient prestress means that always return it into leaktight contact against its seat. 
         [0011]    In a practical embodiment, the valve member includes a valve rod from which a frustoconical brim extends outwards, the brim forming a contact zone, the prestress means also extending outwards from the valve rod. The prestress means are advantageously folded up towards the rod by pressing against the seat while the valve member is being put into place on its seat. When the prestress means are in the form of resilient tabs, said resilient tabs can extend completely radially outwards on being unmolded, and can be folded up towards the rod while the valve member is being put into place on its seat. By pushing the valve member home against its seat, the free ends of the resilient tabs are received under the shoulder of the inlet duct forming the abutment surface. From that moment on, the valve member is held captive by its seat. 
         [0012]    The present invention also defines a method of manufacturing a valve member including: a contact zone for coming into leaktight contact with a valve seat; and resilient prestress means for urging the contact zone towards its seat, the method comprising molding the valve member integrally with the resilient prestress means that are extended in an unmolded configuration, and then deforming the resilient prestress means into an assembled configuration. The prestress means are advantageously deformed against the seat, so as to reach their assembled configuration. The unmolded configuration can be substantially or completely radial, and the assembled configuration defines an axial component that is greater than the axial component of the unmolded configuration. 
         [0013]    The valve member of the present invention thus integrates resilient prestress means that do not require any additional element other than the valve seat in order to become operational. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The invention is described more fully below with reference to the accompanying drawings which show an embodiment of the invention by way of non-limiting example. 
           [0015]    In the figures: 
           [0016]      FIG. 1  is a fragmentary vertical-section view through a dispenser device of the invention mounted in a fluid dispenser; 
           [0017]      FIGS. 2 and 3  are much larger-scale perspective views of the valve member of  FIG. 1 ; 
           [0018]      FIGS. 4   a ,  4   b , and  4   c  are vertical-section views showing a valve member of the invention being assembled on a valve seat; 
           [0019]      FIG. 5  is a view similar to  FIG. 4   b  showing a variant embodiment; and 
           [0020]      FIG. 6  is a view similar to  FIG. 4   a  showing another variant embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]      FIG. 1  is a view of the top portion of a fluid dispenser including a dispenser device  1  mounted on a neck  31  of a reservoir  3  by means of a fastener ring  4 . More precisely, the dispenser device  1  includes a body  10  defining an inlet duct  11  to which a dip tube  14  can be connected. The body  10  also defines a projecting collar  15  that is engaged in a reception housing  41  formed by the fastener ring  4 . In addition, the ring includes a skirt  42  that is internally threaded and that is engaged by meshing with an external thread on the neck  31 . The dispenser device  1  also includes an actuator rod  16  that is axially displaceable down and up at the top end of the body  10 . The actuator rod  16  is associated with a piston (not shown) that slides inside the body  10 . The actuator rod  16  is provided with a pusher  17  that advantageously defines a dispenser orifice  18 . By pressing on the pusher  17 , the user displaces the actuator rod  16 , thereby causing fluid to be dispensed through the dispenser orifice  18 . This is a fairly conventional design for a fluid dispenser in the field of cosmetics for dispensing high-viscosity fluids. The dispenser device  1  can be a pump or a valve. In  FIG. 1 , it is a cosmetics pump. 
         [0022]    Still with reference to  FIG. 1 , it can be seen that the body  10  defines an inlet valve seat  12  that is defined at the outlet  112  of the inlet duct  11 . The inlet  111  of the inlet duct  11  is connected to the dip tube  14 . In this embodiment, the seat  12  is frustoconically shaped, flaring away from the duct  11 , i.e. towards the inside of the body  10 . Under the seat  12 , an inner projection projects into the inlet duct  11  forming an inner shoulder  13  that faces towards the inlet  111  of the duct  11 . With reference to  FIG. 1 , it is also possible to say that the frustoconical seat  12  faces generally upwards, whereas the shoulder  13  faces downwards. In other words, the seat  12  and the shoulder  13  face in diverging or opposite directions. It should also be observed that the shoulder  13  is very simple to form by molding from the inlet  111  of the duct. The frustoconical seat  12  is also simple to form. The seat  12  can also be formed with a shape other than frustoconical, e.g. completely plane. 
         [0023]    The dispenser device also includes an inlet valve member  2  for co-operating with the seat  12  for selectively controlling the flow of fluid from the inlet duct  11  to the inside of the body  10 . The valve member  2  includes a central axial rod  21  that extends along the same axis as the duct  11  and the body  10 . A brim  22  extends outwards in frustoconical manner from the central rod  21 . It can be said that the brim  22  extends outwards and upwards from the rod  21  in a direction and with an inclination that correspond to the direction and the inclination of the frustoconical seat  12 . The brim  22  defines a frustoconical outer contact zone  221  for coming into leaktight contact against the seat  12 , as shown in  FIGS. 1 and 4   b . The brim  22  is spaced apart from the rod  21  by an annular intermediate gap  24  that thus enables the brim  22  to be deformed radially inwards, as described below. The valve member also defines resilient prestress means, which, in this embodiment, are in the form of flexible or resilient tabs or blades  23  that extend outwards from the central rod  21 . In  FIGS. 1  and  4   b , it can be seen that the tabs  23  extend outwards and upwards from the rod  21 . The resilient tabs  23  define free ends  231  that are engaged under the shoulder  13  that thus forms an annular abutment surface. 
         [0024]    The position shown in  FIGS. 1 and 4   b  is the assembled position of the valve member at rest, i.e. when the dispenser is not actuated. It can be seen that the brim  22  is in leaktight contact against the seat  12 , and that the free ends  231  of the tabs  23  bear against the shoulder  13 . As a result, the brim  22  is pressed against its seat  12  as a result of the resilient characteristic of the tabs  23  that are prestressed a little while in the rest position. It is thus not only gravity that causes the valve member to rest against its seat. 
         [0025]    Still with reference to  FIGS. 1 and 4   b , it should be observed that the bottom portion of the valve member  2  is engaged inside the inlet duct  11 , with its top portion projecting inside the body  10 , i.e. beyond the seat  12 . The valve member thus reduces the useful flow section of the inlet duct  11 , which useful flow section is thus merely defined by the slots  232  defined between each tab  231 . 
         [0026]    Reference is made below to  FIGS. 2 and 3  which show, in larger-scale manner, the valve member  2  of  FIG. 1  on being unmolded. This means that the valve member is not yet subjected to any prestress: the tabs  23  extend radially from the central rod  21  in a substantially plane configuration. This can be seen more clearly in  FIG. 4   a . The tabs  23  can be made to curve downwards a little at their free ends  231 , as can be seen in the figures. The curve enables the free ends  231  to hold better under the shoulder  13 . It should also be observed in  FIGS. 2 and 3  that the tabs  23  are separated by slots  232  that define the useful flow section of the inlet duct  11  once the valve member is in place on its seat, as shown in  FIGS. 1 ,  4   b , and  4   c . The intermediate annular space  24  that spaces the brim  22  apart from the central rod  21  can be seen clearly in  FIG. 2 . 
         [0027]    Reference is made below to  FIGS. 4   a ,  4   b , and  4   c  in order to explain how the valve member of  FIGS. 2 and 3  is put into place in a pump or valve body that forms a seat  12 . In its unmolded configuration in  FIGS. 2 and 3 , the valve member  2  is inserted into the body  10  via its top end remote from the inlet duct  11 . The valve member  2  thus comes to rest with its tabs  23  against the top edge of the frustoconical seat  12 . The valve member  2  is not yet subjected to any prestress. From this position, shown in  FIG. 4   a , axial pressure starts to be exerted on the valve member  2  in the direction of arrow F shown in  FIG. 4   b . As a result of their thin wall thickness, the tabs  23  present good flexibility, thereby enabling them to deform elastically by pressing against the seat  12 . The tabs  23  thus fold up towards the central rod  21  while the valve member  2  is being pushed into the seat  12  and the duct  11 . The tabs  23  thus continue to be folded up inside the duct  11  until their free ends  231  are received under the shoulder  13 . To achieve the position shown in  FIG. 4   b , it is necessary to exert relatively strong pressure on the valve member  2 , since it is desirable for the tabs  23  to be prestressed a little while the brim  22  bears against the seat  12  in leaktight manner. It is thus necessary to cause the valve member  2  to penetrate into the duct  11  by deforming the brim  22  a little against the seat  12 . This is possible as a result of the wall thickness of the brim  22  being thin, and as a result of the brim being spaced apart from the central rod  21  by the annular intermediate gap  24 . Because of its frustoconical configuration, deforming the brim  22  makes it possible to displace the rod  21  inside the duct  11  over a distance that is short, but nevertheless long enough to enable the free ends  231  of the tabs  23  to become snap-fastened under the shoulder  13 . The tab ends  231  snap-fasten automatically as a result of the tabs tending to move away from the rod  21  because of their original radial configuration. It then suffices to release the strong pressure exerted on the valve member, so as to allow the brim  22  to relax. This results in the tabs  23  being deformed a little, so they remain prestressed. The brim  22  is thus pressed a little against its seat even in the rest position. This is possible as a result of the brim  22  being more rigid than the tabs  23 . 
         [0028]    In operation, as shown in  FIG. 4   c , the brim  22  can lift off its seat  12 , thereby causing further deformation of the flexible tabs  23  that come to bear harder against the shoulder  13 . The flow passage is thus open between the inlet of the duct  11  and the inside of the body  10 . The fluid flows through the slots  232  defined between the tabs  23 , and around the brim  22 . Such an open check valve configuration occurs when the pressure differential across the check valve is enough to deform the flexible tabs  23 . As soon as the pressure differential is no longer enough, the tabs  23  return to their assembled rest condition shown in  FIG. 4   b , returning the brim  22  into leaktight contact against its seat  12 . 
         [0029]    A characteristic of the check valve of the invention is that it does not require any additional part to provide the function of the valve member being resiliently prestressed against its seat. The valve member co-operates only with the seat and the inlet duct  11 . It should be observed that the seat  12  and the shoulder  13  are situated axially between the brim  22  and the tabs  23 . 
         [0030]    The valve member  2  can be made as a single part by injection-molding a plastics material: the flexibility of the tabs and of the brim coming from their thin wall thicknesses. 
         [0031]    Such a check valve can be used as an inlet valve or as an outlet valve of any dispenser device, such as a pump or a valve, for example. In  FIGS. 4   b  and  4   c , it should be observed that the tabs  23  are deformed or deform outwards by making them more convex. As with reference to  FIG. 5 , it is also possible to envisage that the tabs  23  are deformed inwards by becoming more concave. Both configurations are completely equivalent. 
         [0032]      FIG. 6  shows a variant embodiment for the valve member  2 . In this embodiment, the brim  22 ′ defines a rounded contact zone  221 , such that the contact with the frustoconical seat  12  is made on an annular line, and no longer against a frustoconical surface. In addition, the brim  22 ′ does not extend from the central rod  21 , defining an annular intermediate gap  24 . In contrast, it is the central rod  21  that forms a central gap  24 ′ about which the brim  22 ′ is formed. The brim can also thus deform radially inwards when it is pressed hard against its seat  12 , so as to enable the ends  231  of the flexible tabs to snap-fasten under the shoulder  13 . 
         [0033]    Thus, the annular intermediate gap  24  and the central gap  24 ′ have an identical function of enabling the brim to deform radially inwards into an inner gap when said brim is pressed against its seat. 
         [0034]    In the figures, the seat and the contact zone are frustoconically shaped. However, it is possible to envisage other shapes, e.g. plane. It is also possible to provide a seat of a shape that is different from the shape of the contact zone. 
         [0035]    The resilient prestress means are described as being made in the form of tabs or blades. In a variant, the resilient means can be in the form of a deformable brim. In addition, the resilient means described are situated axially on the seat, inside the inlet duct. However, it is possible to provide resilient means that are situated axially above the seat, e.g. inside the pump body. 
         [0036]    The check valve is particularly well suited to dispensing high-viscosity fluids with which the valve member often encounters difficulties in returning to bear against its valve seat in leaktight manner. This is all the more remarkable given that the valve member is made of a light material, such as plastics material, for example. By means of the resilient prestress means of the invention, the valve member returns immediately against its seat.