Abstract:
An airless dispensing pump for liquid products including a push button with a spray nozzle which communicates with a network of channels that is provided locally on the wall of an internal truncated-cone-shaped bore, and a housing. An upper part of the housing includes a dosing cell having an elastically-deformable wall, which is equipped with an intake valve and topped with a rigid collar for fixing same inside the bore of the aforementioned button. Moreover, the outer periphery of the collar has an inclined face which defines a swirl chamber opposite the above-mentioned network, while the inner periphery thereof is quipped with a passage to the chamber.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   The present application is a continuation of pending International patent application PCT/FR2005/001391 filed on Jun. 7, 2005 which designates the United States and claims priority from French patent application 0406276 filed on Jun. 10, 2004, the content of which is incorporated herein by reference. 

   FIELD OF THE INVENTION 
   The present invention relates to a pump for an airless dispenser of liquid products, and more particularly for a dispenser which dispenses small doses of cosmetic products, perfumes or pharmaceutical products. 
   BACKGROUND OF THE INVENTION 
   Dispensers of this type are generally equipped with traditional pumps consisting of a body which delimits a dosing chamber enclosing a piston and a return spring. 
   However, the various functions of the pump such as, in particular, sealing, compression, elastic return of the piston, dosing, are performed by separate parts which are often made with different materials, some of which have been found to be incompatible with the products in that they degrade the properties of the product over a prolonged residence time or time of contact with said product. 
   In addition, both the manufacture and assembly of these numerous parts are delicate operations, in particular when said parts are of small size. 
   The object of the present invention is to solve these problems in a satisfactory manner. 
   SUMMARY OF THE INVENTION 
   This object is achieved, according to the invention, by means of a pump which is characterised in that it comprises:
         a push button comprising a spraying nozzle which communicates with a network of channels formed locally on the wall of a frustoconical internal bore, and   a body which is provided, in its upper part, with a dosing cell which has an elastically deformable wall and is equipped on the one hand with an intake valve and is surmounted on the other hand by a rigid collar for fixing it in the bore of said button, said collar having on its outer periphery an inclined face which delimits a vortex chamber opposite said network, and having on its inner periphery a passage to said chamber.       

   According to one advantageous feature, this pump comprises an axial rod, borne by said button, which extends through said body and the lower part of which, provided with at least one longitudinal channel, is engaged in a sliding manner in a supply duct which extends said cell while forming the intake valve. 
   According to another feature, the upper edge of said duct is provided with an annular sealing lip which comes into contact with said rod. 
   According to a first variant, said rod is formed in a single piece with said button. In this case, said inclined face of the collar of the cell forms with the wall of the bore of the button a peripheral escape groove which is delimited radially by a flexible lip forming a valve. 
   According to another variant, said rod is an independent piece which is provided, in its upper part, with a central cavity designed to receive a centring pin borne by said button and with a sealing ring which comes to bear against the inner periphery of the collar of said cell while forming an escape valve. 
   Advantageously, said ring is provided with a lower rib which comes to bear in a sealing manner against an annular flange formed on the inner periphery of said collar. 
   In this variant, said ring preferably has teeth which cooperate with notches formed on the inner wall of the bore of the button. 
   According to yet another feature, said body comprises, in its lower part, a bushing for fixing it to a reservoir. 
   Preferably, said bushing comprises a support shoulder for supporting it on said reservoir and at least one spigot which forms a lower stop for said collar during the deformation of said cell. 
   According to another feature, said button comprises a lateral skirt, inside which said body is housed. 
   According to one variant, said cell is produced in the form of a cylindrical bellows-type pocket. 
   It is also possible to provide that said body is extended downwards by a withdrawal tube connected to said intake valve. 
   The pump of the invention makes it possible to combine the functional elements into a very small number of parts or even into the body of the pump itself. 
   The axial rod performs the function of a valve with regard to both intake and escape of the product, which ensures a high level of sealing and also good synchronisation of the opening and closing phases. 
   This pump moreover does not contain any metallic element and can be made solely from plastic which is compatible with the biological and/or chemical properties of the product. 
   Furthermore, assembly of the small number of constituent parts and, in particular, the fixing of the button to the body is possible in particular by virtue of the cooperation between the spigots, which form strengthening reinforcements, and the collar. 
   Moreover, due to the symmetry of revolution of the body and of the rod, this assembly operation can easily be automated without it being necessary to index the parts with respect to one another. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be better understood from reading the following description which is given with reference to the drawings, in which: 
       FIG. 1  shows a profile view of one embodiment of the pump of the invention mounted on a product reservoir, 
       FIGS. 2 and 3  show sectional views of two variant embodiments of the pump of the invention, 
       FIG. 3A  shows an exploded view of the variant of  FIG. 3 , 
       FIG. 3B  shows a detailed view from below of the push button used in the variant of  FIG. 3 , 
       FIGS. 4A to 4E  show the successive phases of operation of the pump of  FIG. 3 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The pump shown in the figures is designed for the airless dispensing of perfume samples, cosmetic products or even of small doses of liquid pharmaceutical products. 
   These products are packaged in a reservoir R which may be made of glass or of plastic, on which the pump of the invention is mounted. 
   This pump comprises a push button  1  provided with a spraying nozzle P. The nozzle P comprises an ejection orifice which communicates with a network of channels C formed locally on the wall of a frustoconical internal bore  10  which can be seen in particular in  FIG. 3B . 
   The pump of the invention also comprises a body  2  housed inside a lateral skirt  11  borne by the button  1 . This body is provided, in its upper part, with a dosing cell  20 , the wall of which is elastically deformable so as to be able to return to its initial shape after having been compressed. 
   In the variants shown here in the figures, the cell  20  is produced in the form of a cylindrical bellows-type pocket which is equipped on the one hand in the lower part with an intake valve and is surmounted on the other hand by a rigid collar  23  for fixing it in the bore  10  of the button  1 . 
   The collar  23  has on its outer periphery an inclined face  23   a  which delimits a vortex chamber opposite the network of channels C, said vortex chamber opening to the outside via the nozzle P. 
   Furthermore, the collar  23  has on its inner periphery a passage for the product from the cell  20  to the vortex chamber, formed by at least one upper peripheral portion  12 . 
   The intake valve consists of an axial rod  3  which is borne by the button  1  and which extends through the body  2 . The rod  3  moves with the button  1 . 
   To this end, the lower part of the rod  3  is provided with at least one longitudinal channel  31  and is engaged in a sliding manner in a supply duct  21  which extends the cell  20  downwards. 
   In the embodiment shown in the figures, the duct  21  is connected to a withdrawal tube  4 , the lower end of which is immersed in the product. 
   The upper edge of the duct  21  is provided with an annular sealing lip  21   a  which comes into contact radially with the rod  3  above the level of the channel  31 . 
   The body  2  also comprises, in its lower part, a bushing  22  for fixing it in or on the neck of the reservoir R. 
   To this end, the bushing  22  is produced either in the form of a stopper which is designed to be introduced with radial locking into the interior of the neck ( FIGS. 2 and 3 , half-views on the right) or in the form of a capsule which clips onto the outside of the neck ( FIGS. 2 and 3 , half-views on the left). 
   In all cases, the bushing  22  comprises a support shoulder  24  for supporting it on the neck of the reservoir R and at least one spigot  25  which forms a lower stop for the collar  23  during the deformation of the cell  20  (see  FIG. 4D ). 
   The lateral skirt  11  of the button  1  has, on its inner wall, a peripheral protrusion  11   a  which ensures that the shoulder  24  clips in and is retained and therefore holds the body  2  inside the button  1 . 
   In the variant of  FIG. 2 , the rod  3  is formed in a single piece with the button  1 . In this case, the inclined face  23   a  of the collar  23  forms with the wall of the bore  10  a peripheral product escape groove which is delimited radially by a flexible lip  23   b  forming a valve. 
   During the dispensing operation, the resistance of the lip  23   b  yields when, by deformation of the cell  20 , the pressure within the product reaches a certain threshold. The product is then expelled towards the vortex chamber via the peripheral groove. 
   In the variant of  FIG. 3 , the rod  3  is produced in the form of an independent piece which is provided, in its upper part, with a central cavity  30  designed to receive, with slight axial play, a centring pin  13  borne by the button  1 . The rod  3  also carries a sealing ring  32  which forms an escape valve. 
   The ring  32  comes to bear in a sealed manner, at the bottom, against the inner periphery of the collar  23  which has, to this end, a flange  23   c  which can be seen in particular in  FIG. 3A . Preferably, the inner face of the ring  32  will be provided with an annular rib  32   a  which makes contact with the flange  21   b.    
   The ring  32  has teeth  33  (three in the present case) with a bevelled end  33   a  which cooperate with corresponding notches  14  formed on the inner wall of the bore  10 . The notches  14  have an inclined outer face which allows the guided displacement of the end of the teeth  33  when bearing against the button. 
   If necessary, the teeth  33  may have a capacity for elastic deformation or elastic flexion within the relevant force range. 
   The operation of the pump of the invention will now be described with reference to  FIGS. 4A to 4E  applied to the variant of  FIGS. 3 and 3A . 
     FIG. 4A  corresponds to the rest position of the dispenser. 
   In this position, the product is packaged in a completely sealed manner, the ring  32  resting with its lower rib  32   a  bearing in a sealed manner against the inner flange  23   c  of the collar  23  so as to close off the cell  20  in the top part. 
   In parallel, at the bottom, the intake valve is open due to the fact that the channel  31  of the rod  3  is located opposite the lip  21   a,  thus forming a means of communication between the cell  20 , the duct  21  and the tube  4 . 
   However, the product contained in the cell  20  remains in suspension. 
     FIG. 4B  corresponds to the initial dispensing phase, with the user starting to exert manual pressure on the upper face of the button  1  so as to compress the cell  20 . 
   The first effects resulting from this force are the downward movement of the button  1 , the taking-up of the axial play between the pin  13  and the cavity  30  and the sliding of the bevelled faces  33   a  on the notches  14 . This phase continues until the teeth  33  and/or the upper end of the rod  3  come into abutment in the top part against the end of the bore  10 . This displacement of the rod  3  relative to the collar  23  brings about opening of the escape valve, by moving the lower rib  32   a  away from the flange  23   c.    
   The upward travel of the rod  3  and thus the rate of opening of the escape valve can be increased if necessary by giving the teeth  33  a certain flexibility. The rod  3  is rapidly pressed down until the upper edge of the channel  31  passes below the level of the lip  21   a,  thus closing the intake valve and isolating a dose of product in the cell  20 . 
     FIG. 4   c  corresponds to the phase of spraying the dose of product. 
   Continuing to press manually on the button  1  brings about deformation of the cell  20  and compression of the product which escapes to the outside via the escape valve by exerting a thrust on the lower face of the ring  23 , then via the upper peripheral passage  12 , the network of channels C, the vortex chamber and finally the nozzle P. 
     FIG. 4D  corresponds to the end of spraying. 
   The lower face of the collar  23  of the cell  20  is then in abutment at the bottom against the spigots  25 , which corresponds to the deformation limit of said cell and to a volume of expelled product equivalent to one dose. At the same time, the escape valve recloses. 
     FIG. 4E  corresponds to the return of the pump to its rest position. The release of pressure on the button  1  brings about expansion of the cell  20  in the manner of a return spring. 
   This expansion of the cell  20  causes the rod  3  to move upwards again, while keeping the escape valve in the closed position and intaking product from the reservoir R via the tube  4  and the duct  21 . 
   The filling of the dosing cell  20  is achieved by an intake of product from the time the channel  31  passes the level of the lip  21   a  of the intake valve until the protrusion  11   a  of the button  1  abuts against the shoulder  24  of the bushing  22  of the body  2 .