Abstract:
A device for dispensing and receiving a liquid or semi-liquid product via a metering chamber of a pump body. The device includes a piston which is fixably mounted in the pump body and is provided with an end sealingly engaged into the chamber. The piston end is provided with an elastically deformable membrane put thereon. The membrane includes a transversal wall forming an input check valve which is provided with a central supply orifice sealingly closable by a protruded element forming the check valve seat on the end of the piston. The membrane includes a fixing cylindrical skirt which is provided with at least one sealing peripheral lip slidingly contacting the internal wall of the chamber. The skirt forms a valve when it is deformed by contact with a projection bearing by the internal wall of the chamber in such a way that the air compressed by the piston is released into the chamber by the pump priming.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of pending International patent application PCT/FR2006/050228 filed on Mar. 14, 2006 which designates the United States and claims priority from French patent application 0551309 filed on May 20, 2005, the content of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to a device for dispensing and intaking a liquid or semi-liquid product, preferably pharmaceutical or cosmetic, by means of a dosage chamber of a pump body. 
     BACKGROUND OF THE INVENTION 
     Such devices are usually designed for dispensing measured amounts of a liquid product, and for watertight sealing of the neck of a bottle containing said liquid product to be dispensed. 
     Devices of this type exist forming a pump and comprising a pump body, a piston mounted fixed in the pump body, a dosage chamber with variable volume into which the end of the piston opens, the chamber communicating with the outside by means of a release valve enclosed in a push button, allowing a dose of product to be dispensed when it is pressed. In addition, the end of the piston is closed by a valve or a second valve for intaking the liquid product in the chamber. 
     Such devices have certain disadvantages, in particular in the pharmaceutical field, since the doses of product dispensed can vary from one spray to the next, while the dispensing of accurate doses is required. 
     Furthermore, when such devices are implemented on bottles without air intake, for example with deformable walls, the pump must have sufficient suction power to reduce the volume of the container. This demand is difficult to meet, which can affect the precision of the doses of product dispensed. 
     Moreover, such devices are very sensitive and their reliability is not always guaranteed. The manufacturer must ensure that the elements forming the pump are centred and aligned around the axis of symmetry of said pump, at the risk of malfunctions that can result in incomplete doses and/or reduced suction power. In addition, when activating the pump, the user must make sure to press the centre of the push button, in order not to cause the compression elements to move off centre and to avoid breaking the seal between the valve and the dosage chamber. 
     Furthermore, the known devices entail problems when priming the pump. Indeed, due to their design, it is difficult to vent the air contained in the dosage chamber before using the dispenser for the first time. 
     SUMMARY OF THE INVENTION 
     The present invention makes it possible to solve the disadvantages of such pumps. 
     It relates in particular to a device designed to be installed independently on a bottle with varying capacity, which is to say a flexible bottle, or deformable bag, or on a bottle with a mobile scraper, or on a rigid bottle with constant capacity, requiring an air intake or not. 
     The device according to the invention comprises a piston which is mounted fixed in the pump body and which has one end engaged in a watertight manner in the chamber, the end of the piston being covered by an elastically deformable membrane. 
     According to the invention, the membrane comprises:
         on the one hand, a transversal wall forming an intake valve being provided with a central supply orifice, capable of being blocked in a watertight manner by a projecting element forming a valve seat on the end of the piston, and   on the other hand, a cylindrical attachment skirt equipped with at least one sealing peripheral lip in sliding contact with the inner wall of the chamber;   the skirt forming a valve by deformation in contact with a boss provided on the inner wall of the chamber, for releasing the air compressed by the piston in the chamber when priming the pump.       

     Thus manufactured, the device according to the invention guarantees the venting of the air contained in the chamber, which allows the pump to be primed before its first use. 
     According to a first embodiment of the device according to the invention, the boss consists of at least one axial rib projecting from the inner wall of the chamber. 
     In order to improve the watertightness, the bottom face of the transversal wall of the membrane advantageously comprises an annular pad centred on the central orifice, and coming to rest against the projecting element of the end of the piston in the valve closing position. 
     According to one advantageous alternative embodiment, the device according to the invention comprises an element for connecting the piston to the pump body, equipped with a bearing for retaining the membrane. 
     Moreover, according to another alternative embodiment, the retaining bearing comprises means for snap-fitting the skirt of the membrane. The snap-fitting means preferably consist of a peripheral groove, made in the lateral wall of the element and cooperating with a snap-fitting bead provided on the inner wall of the skirt. 
     According to a further alternative embodiment, the connection element is an independent part, designed to be added to the bottom part of the pump body. 
     According to yet another alternative embodiment, the connection element comprises a transversal wall forming a bottom, designed to block the body at the bottom. 
     It is advantageously provided for the connection element to comprise a cylindrical bore in which a product intake tube is inserted. 
     The connection element preferably comprises an axial supply conduit, communicating at the bottom with the cylindrical bore. 
     Moreover, it is advantageously provided for the connection element to comprise a peripheral shoulder against which the bottom edge of the skirt of the membrane comes to a stop. 
     It is advantageously provided for the watertight peripheral lip to be made in the proximity of the peripheral shoulder. This makes it possible to improve the watertightness of the device by limiting any radial movement of the membrane, which can offset the projecting element in relation to the central orifice of the membrane. 
     According to yet another embodiment, the device according to the invention comprises an expansion cavity in which the projecting element of the end of the piston is inserted. This cavity is hermetically sealed at the bottom by the projecting element and at the top by the membrane. 
     Finally, it is advantageously provided for the projecting element to consist of a ball mobile between a valve closing position and an opening position in which it allows the liquid product to enter the chamber. 
     The device according to the invention preferably comprises elements for centring the projecting element in the axis of the intake orifice. 
     Thus manufactured, the device according to the invention guarantees not only easy and quick priming of the pump before its first use, but also a perfect seal between the end of the piston and the dosage chamber, regardless of the pressing force and the manner in which the users exerts this force on the push button, or of the area of the push button which the user presses to activate the pump. 
     The device of the invention has a particularly useful application in the field of pump sprayers in which the spray cooperates with a valve having an end needle valve. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further objectives and advantages of the invention will become apparent from the following description made in reference to  FIGS. 1 to 8 , wherein: 
         FIG. 1  shows, in a partial section view, a device according to the invention mounted in a pump; 
         FIG. 2  depicts an embodiment of a membrane which comprises a device according to the invention, in a profile view; 
         FIG. 3  shows a second embodiment of the device according to the invention, in a profile view, the membrane being shown partially in order to illustrate various elements of the device according to the invention; 
         FIG. 4  shows, in a section view, the device shown in  FIG. 3  mounted in a pump body, at the time of priming the pump; 
         FIG. 5  shows, in a section view, the device of  FIGS. 3 and 4  before priming the pump; 
         FIG. 6  is a section view of the device of  FIG. 5  according to the plane E-E shown in  FIG. 5 ; 
         FIG. 7  is a section view of the device of  FIG. 5  according to the plane D-D shown in  FIG. 5 ; and 
         FIG. 8  is a section view of the device of  FIG. 5  according to the plane C-C shown in  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The device described below is particularly suitable for dispensing a pharmaceutical product, such as a medicine, contained in a bottle container. 
     It should, however, be understood that the device according to the invention does not only apply to dispensing a pharmaceutical product, and that it relates to any device corresponding to the definition of the invention capable of being used in any type of pump body. 
     For this purpose, two embodiments of the device according to the invention are presented below. 
       FIG. 1  depicts a first embodiment of the device according to the invention, and  FIGS. 3 to 8  depict a second embodiment. 
     Regardless of the embodiment shown in the figures, the device according to the invention is designed for dispensing a dose of liquid or semi-liquid product, via a dosage chamber  1  of a pump body  2 . 
     In a standard manner, as shown in  FIG. 1  for example, the pump body  2  comprises a hollow cylinder  21  with dimensions allowing it to accommodate the device according to the invention. 
     The hollow cylinder  21  is open at a first end to accommodate an exhaust system, not shown in detail in the figures, which is equipped in particular with a push button  22  and which comprises the dosage chamber  1 . 
     The push button  22  is mounted mobile between a pressed position and a released inactive position in a guiding sleeve  23  assembled in the hollow cylinder  21  of the pump body  2 . 
     A compression spring  24  in the sleeve provides, in this case, the elastic return of the push button  22  from its pressed position to its inactive position. 
     The first end of the hollow cylinder  21  comprises a flange  26  for hooking on the neck of the bottle container. It is possible to provide an annular seal  27 , under the hooking flange  26 , to guarantee the seal with the neck of the bottle. Moreover, an outer girder  28  makes it possible in this case to crimp the pump on the bottle container. 
     In order to facilitate the understanding of the figures, neither the bottle container nor the liquid product are shown. 
     A second end of the cylinder  21  of the pump body is closed around a conduit  25  providing the connection for the end of an intake tube  76  of a liquid product contained in the bottle container on which the pump is mounted. 
     As shown in  FIG. 1 , the device according to the invention, which is mounted in the pump body  2 , comprises in particular a piston  3 . 
     The piston  3  which is mounted fixed in the bottom of the pump body  2 , comprises a top end  31  inserted in a watertight manner in the chamber  1 . 
     The end  31  of the piston is covered by an at least partially elastically deformable membrane  4 , which is more particularly shown in  FIG. 2 . 
     The membrane  4  comprises, on the one hand, a deformable transversal wall  41  forming an intake valve being provided with a central supply orifice  42 , capable of being blocked in a watertight manner by a projecting element  5  forming a valve seat on the end of the piston  3  (see  FIG. 3 ). 
     On the other hand, the membrane  4  comprises a cylindrical attachment skirt  43 , provided with at least one and in this case two peripheral sealing lips  44 , in sliding contact with the inner wall of the chamber  1 . 
     Where applicable, the skirt  43  can be made from a different material which is more rigid than that of the wall  41 . 
     It is provided for the peripheral lips to be made at the bottom of the cylindrical skirt of the membrane, in order to guarantee an optimum seal which is explained in greater detail below. 
     The membrane  4  allows the introduction of a liquid product in the dosage chamber  1 , when a depression is created in this chamber  1 . Indeed, the deformable nature of its wall  41  allows it to lift, separating from the projecting element under the pressure of the liquid, unblocking the orifice  42  and thus allowing the liquid to penetrate into the dosage chamber. 
     According to the invention, the skirt  43  forms a valve by deformation of at least the lips  44  in contact with a boss  6  provided on the inner wall of the chamber  1 , for releasing the air compressed by said piston  3  in the chamber  1  when priming the pump. 
     As shown in  FIG. 1 , the boss consists in this case of at least one axial rib  6  projecting on the inner wall of the chamber  1 . 
     The axial rib  6  comprises a channel  61  which is longitudinal and has a very narrow cross-section, allowing the passage of the air expelled from the dosage chamber  1  when priming the pump. 
       FIG. 4  shows, in particular, the shape taken on by the membrane  4  when the piston  3  is pressed into the dosage chamber. 
     It is noted that the rib  6  crushes the sealing lips  44  without breaking the seal of the liquid product. Indeed, the supporting contact between the groove  6  and the lips  44  does not create a passage for the liquid. Only the channel  61  forming a capillary guarantees the release of the air compressed during the initial phase of priming the pump, said release taking place by passing around the sealing lips  44  and towards the outside of the chamber  1 . 
     In order to improve the watertightness of the intake valve between the membrane  4  and the end of the piston, the bottom face of the transversal wall  41  comprises an annular pad  45  centred on said central orifice  42 , and coming to rest against the projecting element  5 . 
     As shown more particularly in  FIG. 3 , in a partial section view, the device according to the invention comprises an element  7  guaranteeing the connection of the piston  3  to the pump body  2 . 
     The connection element  7  is provided with a bearing  71  for retaining the membrane  4 . 
     The retaining bearing  71  comprises means for snap-fitting the skirt  43  of the membrane  4 . These snap-fitting means consist of a peripheral groove  72 , made in the lateral wall of the element  7  and cooperating with a snap-fitting bead  73  provided on the inner wall of the skirt  43 . 
     The connection element  7  in this case is made as a separate part from the pump body  2 , which is designed to be inserted through the top opening and accommodated in the bottom part of said body. 
     The connection element  7  comprises a base  74  made in the shape of a disc, which guarantees the positioning and coaxial setting of the element. 
     It is provided to make at least one radial recess  79  in the thickness of the disc, cooperating with a rivet (not shown in the figures) projecting from the bottom of the pump body, which prevents all rotation of said device according to the invention when the latter is correctly arranged on the bottom of the pump body. 
     It should be understood that, according to one variation, not shown, the connection element  7  can be added to the bottom part of the pump body  2 , so that the transversal wall  74  forms a bottom blocking said body  2  at the bottom. 
     As can be seen in  FIG. 5  in particular, the connection element  7  comprises, at the bottom, a cylindrical bore  75  in which the tube  76  for intaking the liquid product is inserted ( FIGS. 1 and 4 ). 
     Moreover, the connection element  7  comprises, at the top, an internal conduit  77  for supplying the product to the chamber  1 , the supply conduit communicating with the cylindrical bore  75  ( FIGS. 1 ,  4  and  5 ). 
     As shown in  FIGS. 4 and 5 , the connection element  7  also comprises a peripheral shoulder  78  against which the bottom edge of the skirt  43  of the membrane  4  comes to a stop. 
     As can be seen in particular in  FIG. 3 , an expansion cavity  8  is provided on the end of the piston  3  under the membrane  4 , the cavity  8  being hermetically sealed by the projecting element  5  and by the membrane  4 . 
     The liquid product is introduced in this cavity before penetrating into the dosage chamber  1 . 
     As can be seen in the figures, the projecting element  5  of the end of the piston  3  is inserted in the cavity  8 . 
     According to the first embodiment shown in  FIG. 1 , the projecting element  5  consists of a mobile ball  5  resting between centring elements  51  in the valve closing position. 
     As can be seen in  FIG. 1 , the top end of the supply conduit  77  is made to form a race  9  ( FIG. 1 ) in the shape of a truncated cone, providing support and centring of the ball  5 . 
     According to this embodiment, in the valve closing position, the ball blocks both the end of the supply conduit  77  and the orifice of the membrane  4 . It is thus immobilised between the race and the membrane. Thus, the ball prevents any liquid from entering the cavity  8 , and any liquid from entering the dosage chamber. 
     According to another embodiment shown, for example in  FIG. 4  or  5 , the top end of the connection element  7  comprises slots delimited in this case by two tabs  52  provided on the bearing  71 , designed to extend the conduit  77 . The tabs  52  maintain the projecting element  5  centred in the axis of the conduit  77  and at a distance from its end. The projecting element  5  is thus presented in the shape of a full cylinder with a diameter that is substantially equal to or slightly greater than, the distance separating the two tabs  52 , so that the projecting element is immobilised between the two tabs  52 . 
     According to this embodiment, even if the projecting element  5  only blocks the orifice of the membrane, the liquid can enter the expansion cavity  8 . 
     The cavity  8  can thus be used as a chamber for treating the liquid product. For this purpose, it is possible to insert a chemical or biological agent in such cavity, with which the liquid product can interact by mutual contact or dispersion. This agent can be contained in the material forming the projecting element  5  or on the walls of the cavity  8 . 
     In order better to visualise the space filled by the liquid in the valve closing position,  FIGS. 6 to 8  each show section views of the end of the piston according to several transversal planes. These figures each depict the zones filled by the liquid when the projecting element  5  blocks the orifice  42  of the membrane  4 . 
       FIG. 8  is a section view according to the plane C-C shown in  FIG. 5 .  FIG. 8  shows the liquid (in grey) filling the supply conduit  77 . 
       FIG. 7  is a section view according to the plane D-D shown in  FIG. 5 . This figure shows that the liquid fills the entire free volume of the cavity  8  located under the projecting element  5  and on either side of the projecting element  5 , between the centring tabs  52 . 
     Finally,  FIG. 6  is a section view according to the plane E-E shown in  FIG. 5 . This figure shows that the liquid fills the entire free volume of the cavity  8  located on either side of the projecting element  5 , between the centring tabs  52 . 
     The centring tabs  52  guarantee that the projecting element  5  is always centred on the axis of the supply conduit  77 , and also on the axis of the orifice  42 , to guarantee a regular flow of the liquid and optimum watertightness at the level of the orifice  42  of the membrane  4 . 
     Moreover, the actual position of the peripheral sealing lips  44  on the skirt  43  of the membrane  4  reinforces the sealing capacity of the membrane. Indeed, the closer these lips  44  are to the shoulder, the smaller the risk of the membrane  4  moving and being offset in relation to the axis of the supply conduit. 
     Also, maximum watertightness is guaranteed by the combination of the sealing lips  44  positioned near the shoulder  78 , on the one hand, and the centring elements  51  (or  52 ) of the projecting element  5  forming a valve seat on the end of the piston, on the other hand. 
     The preceding description clearly explains how the invention makes it possible to guarantee the watertightness at the intake of the dosage chamber, by guaranteeing the radial setting of the membrane  4  when a user presses the push button of the pump. 
     In addition, the preceding description clearly describes the means providing the venting of the air contained in the dosage chamber when priming the pump. 
     An advantageous combination of these typical characteristics of the device according to the invention offers the pharmaceutical and/or cosmetic industry a pump:
         that dispenses accurate doses of a liquid product, thanks to the improved watertightness between the membrane and the dosage chamber when the pump is not being used; and   which is easily primed thanks to the means implemented to vent the air contained in the dosage chamber before a first use.