Abstract:
A pump comprising a support-forming assembly for securing to a receptacle containing a substance to be dispensed, a moving member co-operating with the support-forming assembly to define a pump chamber of variable volume, and an elastically deformable diaphragm secured to one of the support-forming assembly and the moving member, the diaphragm being arranged so as to deform elastically when the moving member is displaced relative to the support, the pump further comprising a suction valve-forming element arranged to oppose any return of substance towards the receptacle while the volume of the pump chamber is decreasing, and a delivery valve-forming element arranged to oppose any entry of air into the receptacle while the volume of the pump chamber is increasing. The delivery valve-forming element is made by means of a shutter-forming element that is separate from the diaphragm.

Description:
BACKGROUND OF INVENTION 
     1. Field of Invention 
     The invention relates to a pump for dispensing a substance, in particular a cosmetic. 
     2. Description of the Related Art 
     French patent 2 728 809 discloses a pump comprising a pushbutton mounted to move relative to a support which is secured to a receptacle containing the substance to be dispensed, the pushbutton having a circularly cylindrical central duct provided with radial openings at its bottom end, the support defining an annular pump chamber of variable volume around said duct. 
     A diaphragm made of elastomer is mounted on the support. 
     The diaphragm has a circularly cylindrical central portion in the form of a sleeve that is open at its top end and closed at its bottom end. 
     The central duct of the pushbutton is inserted into the diaphragm until it bears against the bottom of the sleeve-shaped central portion. 
     The diaphragm constitutes a resilient return member enabling the pushbutton to be returned to its initial position after a quantity of substance has been dispensed. 
     In addition, during the return movement of the pushbutton, the diaphragm presses against the central duct, thereby isolating the pump chamber and making it possible to prevent air from penetrating into it. 
     The diaphragm thus acts as a delivery valve. The diaphragm also acts as a suction valve. 
     Such a pump has the advantage of comprising only a small number of parts and thus of being relatively inexpensive to manufacture. 
     Nevertheless, that pump does not give full satisfaction, the Applicant company having observed that the pushbutton tends to jam and/or to dispense poorly and in non-uniform quantities. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     The present invention seeks to improve the operating reliability of a pump of the type defined above, i.e. comprising a support-forming assembly for securing to a receptacle containing a substance to be dispensed, a moving member co-operating with the support-forming assembly to define a pump chamber of variable volume, and an elastically deformable diaphragm secured to one of the support-forming assembly and the moving member, the diaphragm being arranged so as to deform elastically when the moving member is displaced relative to the support, the pump further comprising a suction valve-forming element arranged to oppose any return of substance towards the receptacle while the volume of the pump chamber is decreasing, and a delivery valve-forming element arranged to oppose any entry of air into the receptacle while the volume of the pump chamber is increasing. 
     In the pump of the invention, the delivery valve-forming element is made by means of a shutter-forming element that is separate from the diaphragm and the diaphragm is prestressed when the pump is at rest. 
     Thus, in the invention, the diaphragm can act as a spring without any fear of the moving member jamming; since the element forming the delivery valve is distinct from the diaphragm, there is no risk of the diaphragm impeding departure of the substance leaving the pump chamber. 
     Since the diaphragm is prestressed when the pump is at rest, any clearance at rest is avoided and any risk of substance leaking in the event of the pump being transported is reduced. 
     In the known pump described in French patent 2 729 809, the diaphragm is tensioned when the pushbutton is pushed in, and one consequence of this tension can be to impede the flow of the substance leaving the pump chamber and to make priming difficult. 
     In a particular embodiment, the diaphragm has a central portion in the form of a sleeve that is open at one end and closed at its opposite end, the moving member bearing against said central portion. 
     Still in a particular embodiment, the moving member, i.e. the pushbutton, for example, comprises first and second moving portions that are movable relative to each other, the first portion co-operating with the support-forming assembly to define the variable-volume pump chamber, the second portion being movable relative to the first portion between firstly a dispensing position in which it is suitable for entraining the first portion in the direction to decrease the volume of the pump chamber, and secondly in a position relating to suction in which it is suitable for entraining the first portion in the direction to increase the volume of the pump chamber, the shutter-forming element being secured to the second portion, the first portion having a passage to enable substance to flow towards a dispensing endpiece, the shutter-forming element being movable relative to the first portion between a position relating to closure in which it closes said passage, and a position relating to dispensing in which it ceases to close said passage. 
     Such a pump is relatively easy to manufacture since it has only a small number of parts that are easy to assemble together. 
     In a particular embodiment, the shutter-forming element is in its position relating to closure while the second portion of the moving member is in its position relating to suction, and the shutter-forming element is in its position relating to dispensing while the second portion of the moving member is in its position relating to dispensing. 
     Preferably, the shutter-forming element bears against the diaphragm. 
     When it has a central portion in the form of a sleeve, the shutter-forming element advantageously bears against the bottom of said central portion. 
     Still in the context of the diaphragm including a sleeve-shaped central portion, the above-mentioned passage is advantageously defined by a chimney engaged inside said central portion. 
     In which case, the shutter-forming element advantageously has a rod fixed at one end to the second portion of the moving member, said rod extending inside the chimney and being provided at its opposite end with a valve-forming portion suitable for bearing in leakproof manner against the chimney so as to close it. 
     In a particular embodiment, at least one of the first and second portions of the moving member includes a sealing lip suitable for bearing in leakproof manner against the other portion during relative displacement of these two portions. 
     Thus, the relative movement of the two portions of the moving member can take place without any fear of the substance leaking. 
     Preferably, the sealing lip is formed on the first portion at one end of the above-mentioned passage. 
     In a particular embodiment, the first portion is snap-fastened in the support-forming assembly. 
     Advantageously, this first portion corresponds to the bottom portion of a pushbutton comprising two telescopic portions. 
     In a particular embodiment, the support-forming assembly includes an insert on which the diaphragm is mounted. 
     Still in a particular embodiment, the diaphragm has a peripheral portion defining a groove enabling it to be mounted on the insert. 
     In a particular embodiment, the insert has a suction valve integrally formed by molding a plastic material. 
     In a variant, the peripheral portion of the diaphragm includes a flexible lip forming a suction valve, the support-forming assembly having one or more openings enabling substance to reach the pump chamber while its volume is increasing, said opening(s) being closed by the flexible lip while the volume of the pump chamber is decreasing. 
     The invention also provides a receptacle fitted with a pump as defined above. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other characteristics and advantages of the present invention will appear on reading the following detailed description of non-limiting embodiments of the invention, and on examining the accompanying drawings, in which: 
     FIG. 1 is a diagrammatic axial section view of a pump constituting an embodiment of the invention; 
     FIG. 2 shows the FIG. 1 pump after the pushbutton has been pushed down a little; 
     FIG. 3 is a diagrammatic axial section view through a pump constituting a second embodiment of the invention; 
     FIG. 4 is a fragmentary cross-section view on line IV—IV of FIG. 3; 
     FIG. 5 is a view analogous to FIG. 3 after the pushbutton has been pushed down a little; 
     FIG. 6 is a diagrammatic axial section view of a pump constituting a third embodiment of the invention; and 
     FIG. 7 is a view analogous to FIG. 6 after the pushbutton has been pushed down a little. 
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     FIGS. 1 and 2 show a pump  10  for mounting on a receptacle R which is represented in the figures solely by the top end of its neck  1  which is provided with an annular lip  2 . 
     The pump  10  comprises a static assembly  11  made up of a support  12  and an insert  30 . 
     The support  12  has a tubular skirt  12   a  about an axis X, provided at its top end with a rim  13 , the rim being directed regularly outwards. The tubular skirt  12   a  bears in leakproof manner via its radially outer surface  14  against the radially inner surface of the neck  1  of the receptacle R. 
     The rim  13  is extended radially outwards at several points around its periphery by assembly tabs  15  which are arranged to snap-fasten to the annular lip  2 . 
     The bottom end of the tubular skirt  12   a  is connected via a transverse wall  20  to an endpiece  16  for connection to a dip tube (not shown) so as to enable the receptacle R to be used in the head-up position. 
     Inside the support  12 , the endpiece  16  is extended upwards by a duct  17 . 
     In its bottom portion, the tubular skirt  12   a  has an inwardly directed step  18  which is connected to a cylindrical wall  19  about the axis X for mounting the insert  30 . 
     At its bottom, the cylindrical wall  19  is connected to the above-mentioned transverse wall  20 . 
     At the step  18 , the support  12  has a through orifice  21  for allowing air to penetrate into the receptacle R, as described below. 
     Furthermore, substantially halfway up the tubular skirt  12   a , there is an annular groove  22  formed in its radially inner surface. 
     The bottom of this groove  22  is defined by an annular bead  23  and the top by a shoulder  24  which is situated at the bottom end of a ramp  25  sloping inwards and downwards. 
     The insert  30  has a tubular wall  31  about the axis X which is engaged by force at its bottom end into the cylindrical wall  19 . 
     The tubular wall  31  splits into two at its top end so as to form firstly a radially outer sealing lip  32  and secondly a radially inner extension  33  having a plurality of openings  34  passing through it and spaced around its periphery for a purpose that is explained below. 
     Longitudinal channels  35  are formed in the radially inner surface of the tubular wall  31  extending as far as the openings  34 . 
     The extension  33  serves to secure a diaphragm  40  made of elastomer material, e.g. a nitrile or a silicone elastomer. 
     The diaphragm  40  has a central portion in the form of a sleeve  41  and a flexible annular lip  42  at its top, said annular lip  42  surrounding the sleeve-forming central portion  41  and being connected to the top end thereof by means of a transverse wall  43  that bears against the top end edge of the above-mentioned extension  33 . 
     The central portion of the diaphragm  40  is closed by a bottom wall  45 . 
     The height of the annular lip  42  is greater than that of the openings  34  and the annular lip  42  is arranged, at rest, to bear in leakproof manner against the radially outer surface of the extension  33  so as to be capable of preventing substance returning towards the receptacle R via the openings  34 , as explained below. 
     In addition to the static assembly  11  as described above, the pump  10  also includes a moving assembly forming a pushbutton  50 , the moving assembly comprising a bottom portion  51  which is engaged in part in the support  12 , and a top portion  52  that is movable relative to the bottom portion  51 . 
     The bottom portion  51  has an assembly skirt  53  arranged to snap-fasten in the support  12 . 
     This assembly skirt  53  has a radially inner surface  54  that is circularly cylindrical about the axis X and that has the annular sealing lip  32  of the insert  30  bearing thereagainst in leakproof manner. 
     The assembly skirt  53  also has teeth  56  on its radially outer surface arranged to snap-fasten in the annular groove  22  of the support  12 . 
     The bottom end  57  of the assembly skirt  53  comprises an annular lip that is arranged to bear in leakproof manner against the annular bead  23  when the teeth  56  are resting against the shoulder  24 , as shown in FIG.  1 . 
     This prevents air entering into the receptacle when the pump is at rest. 
     Above the assembly skirt  53 , the bottom portion  51  has a neck  60 . 
     In its radially outer surface, the neck  60  has an annular groove  61  for securing the top portion  52  of the pushbutton. 
     The top portion  52  has an assembly skirt  63  provided at its bottom end with an annular bead  64  that is arranged to snap into the above-mentioned groove  61 . 
     Together with the assembly skirt  53 , the neck  60  forms a shoulder  65  against which the top portion  52  can bear. 
     The bottom portion  51  has a transverse wall  66  which connects to the bottom surface of the neck  60  above the annular groove  61 . 
     This transverse wall  66  supports an annular lip  67  that extends downwards and an annular lip  68  that extends upwards, for functions that are described below. 
     The top portion  52  has an inner skirt  70  whose radially inner surface presents a shoulder  73  at its bottom end, said shoulder  73  axially defining a circularly cylindrical surface  71  against which the top end of the annular lip  68  bears in leakproof manner. 
     A cylindrical housing  74  is formed in the center of the inner skirt  70  for receiving a shutter-forming element  80  which is described below. 
     The top portion  52  has a dispenser endpiece  77  communicating with the space defined by the inner skirt  70 . 
     The annular lips  67  and  68  define a passage  90  that enables substance coming from the receptacle to reach the dispenser endpiece  77 . 
     At its top portion, the shutter-forming element  80  has a rod  81  which is received in the housing  74 , and in its bottom portion it has an internally hollowed-out portion  82  that is connected to the rod  81  by forming a shoulder  83 . 
     This shoulder  83  is arranged to bear against the bottom end of the annular lip  67  when the pump is at rest, as shown in FIG.  1 . The shutter-forming element  80  then has its bottom end  86  resting against the bottom wall  45  of the central portion  41  of the diaphragm  40 ; 
     When the shutter-forming element  80  bears against the annular lip  67  and the bottom portion  51  of the pushbutton bears via its teeth  56  against the shoulder  24 , the tubular wall of the diaphragm  40  extending between the end wall  45  and the transverse wall  43  is under tension. 
     Together with the diaphragm  40  and the shutter-forming element  80 , the bottom portion  51  defines a pump chamber  91  of variable volume. 
     The operation of the pump  10  is described below. 
     It is assumed that the pump  10  is primed. 
     When the pump  10  is at rest, the passage  90  is closed by the shutter-forming element  80  and the bottom portion  51  bears via its teeth  56  against the shoulder  24  under the return action of the diaphragm  40 . 
     When the user presses down the top portion  52 , it begins by coming to bear via the bottom end of its assembly skirt  63  against the shoulder  65  of the bottom portion  51 , so the shutter-forming element  80  releases the passage  90 . 
     Thereafter, the top portion  52  entrains the bottom portion  51  downwards. 
     The downward displacement of the bottom portion  51  reduces the volume of the pump chamber  91  and causes the substance to be delivered via the dispensing endpiece  77 . 
     The pressure in the substance has the effect of pressing the flexible lip  42  against the radially outer surface of the extension  33  as the volume of the pump chamber decreases, thereby preventing any substance returning towards the receptacle R. 
     The downward stroke of the bottom portion  51  continues until its teeth  56  come to bear against the annular bead  23 , thus causing the sealing lip  57  to cease to bear in leakproof manner against the annular bead  23  and allowing air to be taken into the receptacle R via the air intake orifice  21 , the air flowing between the assembly skirt  53  and the support  12 . 
     During the downward movement of the pushbutton  50 , the shutter-forming element  80  bears against the bottom wall  45  of the diaphragm  40  and gives rise to elastic deformation of the central portion  41  of the diaphragm. 
     The diaphragm  40  thus behaves like a spring and confers behavior on the pump  10  that is agreeable to the user. 
     When the user releases the pushbutton  50 , the shutter-forming element  80  is returned by the diaphragm  40  to come into abutment against the annular lip  67 , thereby closing the passage  90 , and then the bottom portion  51  is returned upwards, having the consequence of increasing the volume of the pump chamber  91  and of causing substance to be sucked into it, with the flexible lip  42  moving away from the insert  30  so as to allow the substance to flow through the openings  34 . 
     FIGS. 3 to  5  show a pump constituting a first variant of the invention. 
     The same reference numerals are conserved in these figures to designate elements that are identical to those described above. 
     The pump  110  shown in FIGS. 3 to  5  differs from the pump  10  described above essentially in the shape of its shutter-forming element, in the shape of the bottom portion of its pushbutton, and by the presence of a suction valve that is independent of the diaphragm. 
     In this example, the static assembly  11  of the pump  10  is replaced by a static assembly  111  having an insert  130  which differs from the above-described insert  30  by the presence of a valve  95  that is integrally molded out of the same plastics material as the insert  103 . 
     The valve member  95   a  of the valve  95  is connected to the insert  130  by flexible links  96  which leave it free to move a little along the axis X. 
     At rest, the valve member  95   a  bears against the top end of the duct  17 , as shown in FIGS. 3 and 5, thereby closing it. 
     When substance is sucked into the pump chamber, the valve body  95   a  lifts off the top end of the duct  17  so as to allow substance to pass through, with the links  96  deforming elastically. 
     In the embodiment of FIGS. 3 to  5 , the bottom portion  51  of the pushbutton  50  in the preceding embodiment is replaced by a bottom portion  151  which differs by the fact that the bottom annular lip  67  is replaced by a chimney  167  which extends inside the central portion of the diaphragm  40  and defines a passage  190  for the substance. 
     The top portion  152  has a shutter-forming element  180  which includes a rod  181  fixed at one end in the housing  74 . This rod  181  is provided at its other end with a valve-forming element  183  having an upwardly converging frustoconical surface  183   a.    
     The bottom end of the chimney  167  is shaped to bear in leakproof manner against said frustoconical surface  183   a  when the pump  110  is at rest, i.e. in the configuration shown in FIG.  3 . 
     The valve-forming portion  183  rests permanently against the bottom wall  45  of the diaphragm  40 . 
     The insert  130  differs from the above-described insert  30  by the fact that the extension  33  is replaced by an extension  133  provided with openings  134  which extend over a height that is greater than that of the flexible lip  42  of the diaphragm  40 ; 
     Thus, in the embodiments of FIG. 3 to  5 , the flexible lip  42  serves solely for connection purposes and it no longer performs the additional function of a suction valve, as is the case in the embodiment of FIGS. 1 and 2. 
     The pump  110  operates as follows. 
     It is assumed that the pump chamber  191  as defined by the insert  130 , the bottom portion  151 , and the chimney  167 , is full of substance. 
     When the user presses on the top portion  152 , that causes the shutter-forming element  180  to move downwards relative to the bottom portion  151  so the valve-forming portion  183  moves away from the bottom end of the chimney  167 . 
     The bottom end of the assembly skirt  63  comes to bear against the bottom portion  151  at the end of a predetermined stroke. 
     With continued downward movement of the pushbutton, the volume of the pump chamber  191  decreases and the substance is expelled towards the passage  190  formed inside the chimney  167 . 
     Since the member  95   a  of the valve  95  is pressed against its seat constituted by the top end of the duct  17 , it prevents substance from returning towards the receptacle. 
     While the pushbutton is being pushed down, the central portion of the diaphragm deforms elastically, thereby acting as a spring. 
     When the user releases the top portion  152 , the diaphragm  40  begins by returning the shutter-forming element  180  so that it bears against the bottom end of the chimney  167  in order to close the passage  190 . 
     The top portion  152  is then entrained upwards by the diaphragm  40  which tends to return to its initial shape. 
     The volume of the pump chamber  191  increases and substance is sucked in from the receptacle R. 
     The substance flows via the duct  17 , with the member  95   a  of the valve  95  lifting off the top end of the duct  17 . 
     FIGS. 6 and 7 show a variant embodiment which differs from that of FIGS. 3 and 5 by the fact that the shutter-forming element  180  is replaced by the shutter-forming element  80  as described with reference to FIGS. 1 and 2. 
     The bottom portion  151  of the pushbutton in the preceding embodiment is replaced by the previously described bottom portion  51 . 
     Naturally, the invention is not limited to the embodiments described above. 
     In particular, the suction valve and the delivery valve can be implemented in numerous other ways. 
     For example, the suction valve can be implemented in the form of a ball.